Title:
BILL-VALIDATING APPARATUS
United States Patent 3589514
Abstract:
An apparatus for bill validation wherein the apparatus is enabled upon entry of the paper bill to be examined, whereupon the bill is received and held by a transport for movement past a sensor for detection of predetermined characteristics present on the paper bill. The transport means is controlled to move the bill past the sensor and, simultaneously, additional photoelectric monitoring means disposed along the bill transport path provide additional sensing of the paper bill physical characteristics; failure of a sensor function causes reversal of the bill transport while satisfaction of sensor functions continues transport of the paper bill to an escrow depository.
US Patent References:
Document identifying system
Ett - January 1960 - 2922893
BILL VALIDATING APPARATUS
Townsend - December 1969 - 3481464
DOCUMENT VERIFICATION AND BANKING MACHINE
James - January 1970 - 3487905
Document identifying system
Ett - January 1960 - 2922893
BILL VALIDATING APPARATUS
Townsend - December 1969 - 3481464
DOCUMENT VERIFICATION AND BANKING MACHINE
James - January 1970 - 3487905
Application Number:
04/810974
Publication Date:
06/29/1971
Filing Date:
03/27/1969
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
209/588, D10/46, 250/556, 250/557
International Classes:
G07D7/00; G07D7/00
Field of Search:
250/219DQ,75 209/73,74,111.6,111.7
Primary Examiner:
Knowles, Allen N.
Claims:
What I claim is
1. A paper bill-validating device comprising:
2. A paper bill-validating device as set forth in claim 1 wherein said bill transport means comprises:
3. A paper bill-validating device as set forth in claim 1 wherein said sensor means comprises:
4. A paper bill-validating device as set forth in claim 2 wherein said sensor means comprises:
5. A paper bill-validating device as set forth in claim 3 wherein said photosensing means comprises:
6. A paper bill-validating device as set forth in claim 1 wherein said enabling means comprises:
7. A paper bill-validating device as set forth in claim 2 wherein said enabling means comprises:
8. A paper bill-validating device as set forth in claim 4 wherein said enabling means comprises:
9. A paper bill-validating device as set forth in claim 1 wherein said control means comprises:
10. A paper bill-validating device comprising:
11. A paper bill-validating device comprising:
12. A paper bill-validating device as set forth in claim 11 wherein said sensor means comprises:
13. A paper bill-validating device as set forth in claim 11 wherein said enabling relay circuit means comprises:
14. A paper bill-validating device as set forth in claim 3 wherein said photosensing means comprises:
15. A paper bill-validating device as set forth in claim 14 which is further characterized to include:
16. A paper bill-validating device as set forth in claim 1 which is further characterized to include:
17. A paper bill-validating device as set forth in claim 3 wherein said reactance means comprises:
18. A paper bill-validating device as set forth in claim 17 which is further characterized to include:
19. A paper bill-validating device comprising:
20. A paper bill-validating device as set forth in claim 19 which is further characterized to include:
21. A paper bill-validating device as set forth in claim 19 wherein said control means comprises:
22. In a paper bill-validating device for use with continuously moving paper bills, photosensitive sensing circuitry comprising:
23. Sensing circuitry as set forth in claim 22 wherein said lens means comprises:
24. Sensing circuitry as set forth in claim 23 which is further characterized to include:
25. Sensing circuitry as set forth in claim 24 which is further characterized to include:
1. A paper bill-validating device comprising:
2. A paper bill-validating device as set forth in claim 1 wherein said bill transport means comprises:
3. A paper bill-validating device as set forth in claim 1 wherein said sensor means comprises:
4. A paper bill-validating device as set forth in claim 2 wherein said sensor means comprises:
5. A paper bill-validating device as set forth in claim 3 wherein said photosensing means comprises:
6. A paper bill-validating device as set forth in claim 1 wherein said enabling means comprises:
7. A paper bill-validating device as set forth in claim 2 wherein said enabling means comprises:
8. A paper bill-validating device as set forth in claim 4 wherein said enabling means comprises:
9. A paper bill-validating device as set forth in claim 1 wherein said control means comprises:
10. A paper bill-validating device comprising:
11. A paper bill-validating device comprising:
12. A paper bill-validating device as set forth in claim 11 wherein said sensor means comprises:
13. A paper bill-validating device as set forth in claim 11 wherein said enabling relay circuit means comprises:
14. A paper bill-validating device as set forth in claim 3 wherein said photosensing means comprises:
15. A paper bill-validating device as set forth in claim 14 which is further characterized to include:
16. A paper bill-validating device as set forth in claim 1 which is further characterized to include:
17. A paper bill-validating device as set forth in claim 3 wherein said reactance means comprises:
18. A paper bill-validating device as set forth in claim 17 which is further characterized to include:
19. A paper bill-validating device comprising:
20. A paper bill-validating device as set forth in claim 19 which is further characterized to include:
21. A paper bill-validating device as set forth in claim 19 wherein said control means comprises:
22. In a paper bill-validating device for use with continuously moving paper bills, photosensitive sensing circuitry comprising:
23. Sensing circuitry as set forth in claim 22 wherein said lens means comprises:
24. Sensing circuitry as set forth in claim 23 which is further characterized to include:
25. Sensing circuitry as set forth in claim 24 which is further characterized to include:
Description:
CROSS-REFERENCE TO RELATED APPLICATION
The subject matter of the present application is particularly related to that invention subject matter contained in U.S. Pat. application Ser. No. 658,079 entitled "Bill Validating Apparatus" filed on Aug. 3, 1967 by the present inventor, now U.S. Pat. No. 3,481,464.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to document validation devices and, more particularly, but not by way of limitation, it relates to improved apparatus for readily ascertaining the validity of paper currency to selectively enable payout and/or coin-change apparatus.
2. Description of the Prior Art
The prior art includes various types of bill-validating apparatus which employ one or more of various types of sensing such as photoelectric, magnetic, thickness-testing conductivity, etc. There are various types of such equipments which tend to utilize photoelectric means alone, or such photoelectric means in combination with another form of detection, e.g. magnetic sensing. These devices function to a high degree of satisfaction and presently find employ in diverse fields. There still exist some shortcomings in operation of those types of device utilizing photoelectric cells due to various inherent factors present within the photoelectric or photoconductive cells utilized. Such factors are generally those which necessitate combination of photoelectric operation with another form or mode of bill characteristic detection.
SUMMARY OF THE INVENTION
The present invention contemplates bill validation apparatus utilizing photoelectric detection means to examine a document or paper bill for a selected physical characteristic, thereafter to escrow or return the bill or document in accordance with the finding. The invention includes a transport means for receiving and carrying a bill or document to be examined whereupon the bill is moved at a predetermined rate past a photoelectric sensing station to check for validity while additional photoelectric means are utilized to signify bill presence and position of traverse along the transport path. Control means functioning in response to validity finding of the bill by the sensor means controls the transport means to deliver the bill to escrow; or, if invalid, to return it backward out to the point of entry. The invention utilizes a particular form of bill characteristic sensing as it photoelectrically inspects grid or line portions of bill printing to derive a sense indication dependent upon proper line spacing, a photoelectric sense reading is applied to an amplifier which provides an output indicative of the required line or grid periodicity.
Therefore, it is an object of the present invention to provide an improved bill-validating device which is more compact in size and more reliable in detection.
It is also an object of the invention to substitute photoelectric devices for mechanical control switching thereby to provide increased reliability at lower cost of manufacture.
It is still another object of the invention to provide bill detection apparatus which may utilize a single bill characteristic sensing device of the photoelectric type with a high degree of accuracy and reliability.
Finally, it is an object of the present invention to provide a bill-validating device which is uniformly small, lightweight and applicable to diverse bill-changing requirements, and which is highly reliable and offering increased resistance to all known piracy techniques.
Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawings which illustrate the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of validating apparatus constructed in accordance with the present invention;
FIG. 2 is a vertical section taken along lines 2-2 of FIG. 1;
FIG. 3 is a partial section of validating apparatus of FIG. 1 as taken along lines 3-3;
FIG. 4 is a schematic diagram of the control circuitry of the validating apparatus of FIG. 1;
FIG. 5 is a schematic diagram of amplifier circuitry which is employed in the validating apparatus of FIG. 1;
FIG. 6 is a form of heater circuit which may be employed in the control circuitry of FIG. 4;
FIG. 7 is a form of heat control circuit which may be employed in the control circuitry of FIG. 4;
FIG. 8 is an alternative form of heat control circuit which may be employed in the control circuitry of FIG. 4;
FIG. 9 depicts in vertical section an alternative design for a bill-sensing device to be utilized in the validating apparatus; and
FIG. 10 is a figurative illustration of still another form of bill characteristic sensing device which may be utilized.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a bill-validating apparatus 10 consists of a frame member 12, a rectangularly bent metal frame, having opposite side panels 14 and 16 (not shown) which are suitably secured thereon in removable manner. A front opening 18 is provided through a front panel 20 of frame 12 to accommodate bill reception through a bill-receiving tray 22 having respective left and right side panels 24 and 26 and being securely affixed in an entry position.
Referring now to FIG. 2, the interior of validating apparatus 10 includes a plurality of electronic components 28 mounted in operative relationship on a circuit board 30 which, in turn, is mounted by suitable insulative mounting means (not specifically shown) inside of rear panel 32 of rectangular frame 12. A drive motor 34 including a suitable reduction gearbox 36 is mounted on the side panel 16 to support a rotary drive shaft 38 and drive pulley 40 in proper operative relationship as will be described. Although a matter of choice, the drive motor 34 and selected gearbox 36 may be separate, commercially available items; however, as shown in FIG. 2, the motor 34 and gearbox 36 may be obtained as an integral unit having selected power requirements and predetermined drive output speed and torque. Thus, the motor 34 may be a conventional capacitor run AC motor which may be selected from various commercially available types. In some applicants it may also be desirable to employ a reversible, shaded pole motor or well-known design.
The drive pulley 48 is in engagement with a transport belt 42 which may be the toothed, nonslip variety as shown. The transport belt 42 is positioned by idler pulleys 44 and 46 and tension pulley 48 so that it will contact around about one-half of the circumference of a transport disc 50. The transport disc 50 is rotatable on a shaft 62 and should be formed of relatively smooth material so that a paper bill or such can be held around its circumference beneath transport belt 42. The thickness of transport disc 50 is not critical; however, one form of the invention maintains the transport disc 50 at the same thickness as the width of transport belt 42, i.e. about three-eighths inch.
Referring also to FIG. 3, a pair of arcuate slide plates 52 and 54 located on the near and far side respectively of transport disc 50, are rigidly secured approximate the entry access hole 18 to serve as side guides for an inserted paper bill. Thus, the arcuate side guides 52 and 54 may each be formed integrally with the entry plate 22, the entire piece being rigidly secured by suitable fastening techniques such as a plate 56 secured by a bracket 58. A bracket 60 secured as by spot welding to side guide 52 may be supported on the positioning shaft 62 which is securely journaled between opposite side panels 14 and 16 of validating apparatus 10, and which also serves to maintain the transport disc 50 in operative position. A similar bracket (not shown) would support side guide 54 on the further side of transport disc 50.
The idler pulleys 44 and 46 are suitable supported on respective shafts 64 and 66 and tension pulley 48 is similarly supported in rotational manner on a shaft 68. The shafts 64, 66 and 68 may also be suspended in rigid manner between suitable journal affixures on the respective side panels 14 and 16. A tension bar 70 is supported by a pair of side brackets 72 (the near one not being shown) which are pivotally affixed about a journaled shaft 74. A pair of tension springs 74 (the near one again not being shown) such that tension bar 70 is urged upward about pivot axis or shaft 74. A solenoid 78 is mounted on side panel 16 and positioned to extend armature 80 into pivotal contact with shaft 64. The bracket plate 69 is formed with an angularly shaped lower edge 82 which coacts with a knife plate 84 suspended by a flange connection 86 for movement with bracket plates 69 and axle 64 about the pivot shaft 68. Thus, upon actuation of the solenoid 78 as will be further described below, bracket plate 69 is urged leftward, (relative to FIG. 3) and lower edge 82 of bracket plate 69 bears against a suitable spacer or roller 88 to force the pivotal brackets 72 downward, this allowing a bill passage spacing between knife plate 84 and roller 88. The knife plate 84 in its relaxed state tends to hold a bill against roller 88 to prevent piratelike removal back along the transport route as by a thread attachment or such.
A plurality of photocells are employed to perform various function actuations within the validating apparatus 10. Thus, a lamp 90 is mounted so that it can be viewed through an entry aperture 92 in entry plate 22 by an entrance photocell 94 which is held by means of a suitable supporting tube 96 and bracket 98 attached to a securing post 100. A second photocell 102, a light burnout or safety photocell is mounted directly below lamp 90 in viewing relationship thereto. Still an additional photocell 104, the reject and "hold on" photocell, and photocell 106, the "turnoff" photocell, are each supported on opposite sides of a bracket 108 which is secured in keyed manner on shaft 68 so that photocells 104 and 106 continually view the lamp 90.
The bill-verifying photoconductive cell 110 is retained within a barrel 112 which is supported by a suitable bracket 114 suspended from securing post 100 as can be seen to best advantage in FIG. 3. Thus, the photoconductive cell 110 is held by barrel 112 for viewing through a hole 116 in arcuate slide plate 54 to a bill-verifying light source, a lamp 118, as supported by bracket 120 affixed to transverse shaft 62.
The barrel 12 includes the photoconductive cell 110 at its upper end with a selected grid or mask 122 disposed across the interior of the barrel at a selected midpoint which provides proper focal registration. The mask 122 is a selected line structure which should provide a selected moire effect upon comparison with a particular line structure of ink printing on the document to be examined. Thus, in the case of examination of portrait background on a 1 dollar bill, a line structure of about 120 lines per inch will provide the proper grid function or moire effect as relied upon in the electronics, to be further described below. This line structure will vary with different denominations of paper money or with any other pattern for which the device may be utilized in recognition. An objective lens 124 is disposed across barrel 112 at a distance which will provide proper focus as between a bill or document disposed on arcuate slide plate 54 and the image plane at mask 122. It is contemplated that barrel 112 be of sectional construction to enable various sliding adjustments as to focus and imaging of the recognition structure.
Referring now to FIG. 4, control circuitry 130 provides actuation control for the bill validation apparatus 10. AC line voltage is applied in between a high side lead 132 and a lead 134 which may be connected directly to a common lead 136. The bill inspection lamp 118, e.g. a 110-volt AC, 6-watt lamp bulb, is connected directly across the AC line between lead 132 and common lead 136.
A voltage-dropping resistor 138 is connected between AC lead 132 and a rectifier 140 which provides half-wave DC voltage at junction point 142, which DC voltage is employed for various functions to be further described. The light burnout or safety photocell 102 is connected between junction 142 and a junction 144 which is connected via lead 146 and a resistor 148 to common 136. Junction point 144 is further connected to a resistor 150 in series with a junction 152 and the entrance photocell 94 to common 136. A lead 154 is connected from junction 142 to a coil 156 of the "turn on" relay.
A neon lamp 158 in series with a resistor 160 is connected between the junction point 152 and a junction point 162 which is further connected through a resistor 164 to the gate electrode of a semiconductive controlled rectifier 166. The junction point 162 is connected through a thermal conduction device 168, a thermistor or other such heat-regulating device (as will be further described), to the common lead 136, as well as through a resistor 170 junction 172 and a dropping resistor 174 to the DC supply lead 154. A control diode 176 is then connected between junction 144 and the junction 172 to provide isolation relative to the light burnout photocell 102 to insure that the circuitry is completely disabled when lamp 90 burns out.
The relay coil 156 has one end connected to the DC half-wave supply on lead 154 while the other end is connected through a voltage-dropping resistor 178 to the anode of the controlled rectifier 166. A capacitor 180 and resistor 182 are connected in series across relay coil 156 to provide the necessary damping upon energization of the "turn on" relay coil 156. The cathode of control rectifier 166 is connected directly to common 136. The relay coil 156 actuates wiper contacts 184 and 186 to apply voltage energization to the remainder of the control circuitry 130. Thus, wiper contact 186 is connected to the AC lead 132 and, when relay coil 156 is energized, wiper contact 186 makes with contact 188 and a lead 190 which conveys AC voltage to various additional circuit components. The wiper contact 184 applies rectified DC via lead 192. Contact 184 connection in the normal position is through contact 194 to a lead 196 through a resistor 198 to a grounded or common junction point 200, and in the energized position, the conduction is via contact 202 to a rectifier 204 and resistor 206 which, is energized from the AC lead 190.
A "reject" relay is controlled by a relay coil 208 which is energized via a lead 210 from a junction point 212 energized by a rectifier 214. The rectifier 214 and a dropping resistor 216 are connected back to the AC lead 190 which is enabled by energization of the "turn on" relay coil 156. The "reject" relay coil 208 is connected through a resistor 218 to the anode of a control rectifier 220 and a capacitor 222 in series with the resistor 224 is connected across the relay coil 208. The gate electrode of controlled rectifier 220 is connected through a resistor 226 and diode 228 to a junction point 230. A neon lamp 232 is connected between junction point 230 and a junction point 234 while junction point 234 is biased above common by the "hold on" photocell 104. Junction point 234 is connected back to junction point 144 through a resistor 235 by means of a lead 236.
The junction point 230 is also connected through a diode 238 to a junction point 240 which is shorted to the junction point 162 in the "turn on" circuit. The junction point 240 is also connected in series through a resistor 242 and series-connected diodes 244 and 246 to common. A capacitor 248 conducts control input from photocell 106 as energized by DC voltage from 250 and series resistor 252.
The cathode of controlled rectifier 220 is connected via a lead 256 back to a point of DC reference at junction point 172. The cathode of controlled rectifier 220 is also connected via lead 258 to a connection which is normally grounded prior to validation output as will be further described. A lead 260 provides holding contact from the anode of controlled rectifier 220 back to the "reject" contact 262 which, upon energization, makes through wiper contact 264 and lead 266 to common. In its normal position, wiper contact 264 makes with contact 268 to maintain ground potential on a lead 270 that is connected to the cathode of a controlled rectifier 272 which controls the "validate" relay coil 274. The "reject" relay coil 208 also controls application of the AC supply lead 190 through wiper contact 276 to the drive motor 34.
Thus, in its normal or deenergized position, contact 278 applies AC voltage via lead 280 to one side 282 of the motor-energizing coil 284. In its energized position, wiper contact 276 makes with a contact 286 to apply AC voltage via lead 288 to the remaining side 290 of energizing coil 284. A center tap 292 is connected via lead 294 through lamp 90 to common 136. A pair of Zener diodes 296 and 298 of selected rating are connected series-opposed across lamp 90 to maintain a 6 volt DC energizing source for the DC lamp 90.
A running capacitor 300 is connected across motor-energizing winding 284 in shunt. An additional motor winding 302 may be optionally included for the purpose of providing an isolation output across terminals 304 and 306. This would amount to a space-saving measure where the motor-energizing coil 284 is employed as a transformer primary while secondary coil 302 derives an AC output for use in energizing the remainder of the circuitry. This is particularly attractive for the purpose of providing isolation between the AC line and the control circuitry 130 for safety purposes. It should be understood too that there are other commercially available forms of reversible AC motor which can be employed in the present invention with little or no application variations.
The "validate" relay coil 274 is connected between the DC junction point 212 and the anode of controlled rectifier 272. The capacitor 308 and resistor 310 are connected across relay coil 274 and in parallel with a current-limiting resistor 312 while a lead 314 provides a relay holding connection. The gate electrode of control rectifier 272 is connected through a capacitor 317 to the normally grounded lead 270 and also through the wiper element of a potentiometer 318 connected between normally grounded lead 270 and a resistor 320 leading to a control input 322 which is connected to a validation amplifier (FIG. 5) as will be further described in detail. Positive going signal input at amplifier input 322 causes controlled rectifier 272 to conduct to energize the "validate" relay coil 274.
When relay coil 274 is energized, a wiper contact 324 applies AC voltage from lead 132 to a contact 326 which connects to lead 328 supplying AC voltage to the solenoid 78. A second wiper contact 330, connected via lead 332 to a voltage storage capacitor 334, breaks connection with a contact 336 and lead 338 to one side of a "payout" relay coil 340. Also when coil 274 is energized, wiper contact 330 makes with contact 342 to a lead 344, a DC source from a rectifier 346 and dropping resistor 348 connected in series from lead 192. Still further, a third wiper contact 350 breaks a connection through contact 352 and lead 354 to the cathode of controlled rectifier 220, the "reject" controlled rectifier, to make with a relay contact 356 and the relay hold lead 314.
A lead 360 connects the remaining side of "payout" relay 340 to ground such that its energization depends from wiper contact 330 of the "validate" relay. The "payout" relay coil 340 energizes a single, normally open wiper contact 362 into contact with a normally open contact 364 to short circuit leads 366 and 368 to provide a validity output signal to an external payout circuit. The external payout circuit may be any of the conventional bill, ticket, coin, etc. dispensing mechanisms which might be employed with the particular bill-validating apparatus 10. DC voltage for use throughout the system is generated upon energization of the "turn on" relay coil 156. Thus, wiper contact 184 mates with contact 202 which, through the action of rectifier 204 connected back to AC source lead 190, provides DC voltage via lead 192 which is available at a junction point 370. The DC voltage 370 is available on a lead 372 for output at a DC 1 terminal 374, adequate filtering being effected by a capacitor 376 connected to ground or common 136. A reduced value of DC is present at DC 2 terminal point 378 as derived via lead 380 from junction point 382. A dropping resistor 384 is connected between terminal point 370 and terminal point 382, and additional capacitor filtering is provided by a capacitor 386 connected between terminal point 382 and common 136.
Referring now to FIG. 5, an amplifier 390 is energized by DC 2 voltage at input terminal 379, DC 1 voltage at input terminal 375 and AC line voltage at an input terminal 392. The validity recognition photocell 110, as shown also in FIG. 2, is connected between common lead 394 and a junction point 396 which is energized by a potential determined by a voltage-dropping resistor 398 connected to the DC 2 input source 379. Input voltage variation at junction point 396 is applied through a coupling capacitor 400 to the base of an NPN-type transistor 402 having its emitter connected directly to common lead 394. The collector of transistor 402 is connected through a load resistor 404 to a DC supply lead 406 which is energized through an additional series load resistor 408 connected to the DC 1 voltage source 375. A Zener diode 409 connected between lead 406 and common provides voltage regulation. A biasing resistor 410 and parallel-connected feedback capacitor 412 connected between the collector and base of transistor 402 serve to effect neutralization by providing degenerative feedback.
The output from transistor 402 is taken from the collector for application through a coupling capacitor 414 to the base of an emitter-grounded, NPN-type transistor 416. Amplification is effected by serial amplification in a cascade of transistor amplifier stages of similar configuration. Thus, in the manner of emitter-grounded connection of transistor 402, each of NPN-type transistors 416, 418, 420 and 422 are similarly connected for energization through the respective parallel load resistors 424, 426, 428 and 430, as interconnecting output signal coupling is effected by coupling capacitors 432, 434, 436 and 438, respectively. Collector-base neutralization and biasing for each amplifier stage is effected by the respective degenerative feedback networks, resistance-capacitance networks 440, 442, 444 and 446.
A final amplifier output is conducted through capacitor 438 for application to an output doubler circuit consisting of grounded diode 448 and serial diode 450 which charges storage capacitor 452. Charge buildup on capacitor 452 is conducted through a resistor 454 for application to the base of NPN-type transistor 456 which provides emitter output via amplifier output lead 458, i.e. input 322 to the control circuitry 130 (FIG. 4). In the case of a single validation channel, a single transistor 456 is employed with DC energization effected through bypass lead 460 (dash line) connected to the DC voltage source lead 406. In the event that a second validation channel input is employed, the input 462 is applied to a second serial transistor stage 464 through a base resistor 466. The addition of extra validation input channels is a matter of choice depending upon design exigencies and, in any event, a filter capacitor 468 is connected between the voltage supply lead 406 and common lead 394.
An accessory circuit, a density regulation circuit 470, may also be included in the amplifier circuitry 390 to further refine the operation and increase the capabilities of the validation device. The density circuit 470 is energized by the DC potential lead 406 as applied across a network including density-reading photocells 472 and 474. Density reading photocell 472 is connected between the DC source lead 406 and a junction point 476, and a potentiometer 478 is connected between point 476 and common lead 394. In opposite disposition, a density photocell 474 is connected between common lead 394 and a junction point 480 whereupon a potentiometer 482 is connected between junction point 480 and the DC source lead 406.
Junction point 476 is connected through a diode 484 to a junction point 486 while junction point 480 is connected in parallel through a diode 488. Junction point 486 constitutes the input through a dropping resistor 490 to the base of an NPN-type transistor 492 which is connected common-emitter as it has the collector lead 494 coupled directly to the base of output transistor 456. Thus, diodes 484 and 488 constitute an OR gate input-controlling transistor 492 which, in turn, controls conduction of transistor 456 to provide the amplifier output. The density-reading photocells 472 and 474 are so connected that either an undue dark reading at photocell 474 or an undue light reading at photo cell 472 will actuate through the respective OR gate diodes 488 and 484 to energize transistor 492 so that output transistor 456 is blocked to cancel any signal output on amplifier output lead 458.
Additional OR gate inputs to the base of transistor 492 are coupled through diodes 496 and 498. The diode 498 receives signal input from the 110-volt AC line at input 392 as conducted through a capacitor 500 biased above ground by a resistor 502. AC signal at a junction point 504 is full-wave rectified and doubled by diodes 506 and 508 for input through diode 498. A capacitance 510 and parallel-connected resistor 512 are connected between the anode of diode 498 and common lead 394. The DC 2 voltage at input terminal 379 is applied through a capacitor 514 to a terminal 516 and DC return is provided through a resistor 518. The voltage variations at junction point 516 are applied to the anode of diode 496. Thus, diodes 496 and 498 constitute further OR inputs to the base of control transistor 492.
OPERATION
The validating apparatus 10 can be employed in various types of coin-change, laundry operation, and dispensing machines to mention only a few possible applications. Each validating apparatus 10 is first preadjusted for its particular application. Thus, the recognition optics within the barrel 112 must be adjusted for proper focus and line masking. The mask 122 is selected to have a line pattern which will exhibit a desired moire effect with a certain denomination of paper money. As previously mentioned, if recognition requires a view of the portrait background on a 1 dollar bill, the line structure of about 120 lines per inch, 50 percent open, will provide the proper grid function. The barrel 112 and objective lens 124 are also adjusted to provide most accurate imaging at the plane of the mask 122.
In its standby state there is no AC voltage distributed throughout the validating apparatus 10. Entry of a paper currency bill on entry plate 22 will block the entry aperture 92 such that illumination from lamp 90 is removed from view of the entrance of photocell 94. As shown in FIG. 4, darkening of photocell 94 increases its resistance such that the voltage increase at terminal point 152 is reflected to terminal point 162 and the increase in positive voltage is received at the gate electrode of semiconductive control rectifier 166 to trigger it into conduction. The conduction permits maximum current flow from positive voltage junction point 142 through the "turn on" relay coil 156, thereby to energize the "turn on" relay. The energization closes relay contacts 186 and 184 to their energized positions whereupon AC line energization from the lead 132 is applied via a lead 190 for distribution to energize the circuitry throughout the validating apparatus 10. A DC potential as derived from AC lead 190 through rectifier 204 is available on lead 192 for application variously as will be described below. The AC energization on lead 190 is applied through the "reject" relay contact 276 (normal position) for conduction via lead 280 to energize drive motor 34 in its forward rotation. Thus, the paper bill which was previously introduced on entry plate 22 will be gripped by the moving transport belt 42 and carried up around arcuate guide plates 52, 54 and the transport disc 50.
The paper bill is moved at a constant rate around transport disc 50 by means of transport belt 42, and positioning is such that a selected line-grid portion of the bill print, e.g. portrait background, is maintained in viewing relationship to the barrel 112 holding the recognition optics. Thus, as shown in FIG. 3, the selected portion of the bill will pass over aperture 116 to receive light transmission from lamp 118 for inspection by mask 122 and photocell 110.
The photocell 110, e.g. a cadmium sulfide photoconductive element, exhibits change in resistance with a change in light and it is affected by a moire effect pattern as the combined light from the bill print structure and mask 122 is projected on the sensitive surface of photocell 110. If there is in fact proper portrait background, i.e. the proper number and spacing of lines and spaces, the resistance of photocell 110 will be changed at a predetermined frequency which is distinguished by the amplifier circuitry 390 (FIG. 5) as being a proper or valid background recognition. The amplifier circuitry 390 is energized by the proper frequency input from photocell 110 to provide an amplified output via lead 458 which is then employed to actuate the "validate" relay in control circuitry 130 (FIG. 4) as will be further described.
A recognition input from varying resistance of photocell 110 is applied from terminal point 396 through coupling capacitor 400 for serial amplification in the respective cascaded amplifiers, transistors 402, 416, 418, 420 and 422. The resistor 398 and coupling capacitor 400, as considered with the resistance of photocell 110, are selected values which contribute to the desired frequency response, i.e. a pass band on the order of 300 to 400 cycles which is effectively an open circuit below 120 cycles. Amplified output from the final amplifier transistor 422 is applied through a coupling capacitor 438 and then doubled for application to the base of an output transistor 456. Emitter output from transistor 456 is then applied via lead 458 for input to the amplifier input 322 of control circuitry 130 in FIG. 5. The transistor 456 may be coupled for energization as by dashline 460; or, a second output transistor 464 may be connected in series to provide output in response to energization by a second recognition channel input at input 462. Such second channel input 462 may receive signal from a concurrently employed sensor of well-known type e.g. magnetic sensing, pierce-test sensing, other photoelectric sensing devices, etc.
The essential operation of amplifier circuitry 390 is complete as set forth above, but it may be further enhanced by the inclusion of sensity test photocells which provide further validation as to the type or density of the paper material. Thus, photocells 472 and 474 may be suitably disposed within validating apparatus 10 (FIGS. 2 and 3) in a position whereby they view the light source 90, the position being such that the bill being tested will pass between lamp 118 (or other validating lamp) and photocells 472 and 474 during the validation function. The potentiometers 478 and 382 may be preadjusted to set a threshold and upper limit, respectively, of energization as derived from light passing through the paper material of the currency. Thus, if not enough light is seen by photocell 474, the voltage at terminal 480 is increased to cause conduction of transistors 492 such that the base of amplifier output transistor 456 is effectively grounded and cut off so that no validating output can be conducted. On the other hand, if greater than a predetermined amount of light is present and detected by photocell 472 the voltage at terminal 476 is raised above a predetermined threshold setting, and this too will bring about conduction of transistor 492 to ground the base of transistor 456 and block amplifier output via lead 458.
Further blocking inputs may be received through the OR gate diodes 496 and 498. The diode 496 is connected to terminal 516 and input capacitor 514 from the DC 2 source 379 to provide blocking of amplifier output transistor 456 when the unit is first turned on. That is, input through diode 496 will hold transistor 492 in conduction until the control circuitry 130 warms up or reaches its stable operating level throughout the circuitry. The diode 498 provides blocking of amplifier output transistor 456 in the event that line transient voltages, e.g. motor brush transients, inductive kickback voltage fluctuations, etc., are present on the AC line to the validating assembly 10.
Referring again to FIG. 4, a signal representative of a valid recognition may be received at input 322 whereupon it is applied to gate electrode of the semiconductive control rectifier 272 to cause conduction and energize the coil 274 of the "validate" relay. The energized "validate" relay applies AC from lead 132 to contact 324 to a lead 328 which energizes the solenoid 78 (see also FIGS. 2 and 3). Solenoid 78 serves to move idler pulley 46 and, therefore, the lower portion of transport belt 42 into position to guide the valid bill into an escrow compartment associated with validating apparatus 10. Also, it operates to position the knife plate 84 to prevent cheating by withdrawal of the bill after payout actuation.
The "validate" relay contact 330 is closed to apply DC voltage from rectifier 346 and lead 344 through a lead 332 to charge up a capacitor 334 which is connected to the grounded junction point 200. Thus, upon release of the "validate" relay to its normal contact position, lead 332 is connected through contact 330 to contact 336 and lead 338 to apply the stored electrical charge from capacitor 334 across "payout" relay coil 340 to energize it sufficiently to provide a circuit-closure actuation as between external payout circuit leads 366 and 368. The charge from capacitor 334 is merely a pulse sufficient to momentarily actuate the "payout" relay coil 340.
Still a further function of the "validate" relay is to disconnect the grounded relay contact 350 from contact 352 which connects via lead 258 to the cathode of the controlled rectifier 220, the "reject" actuator controlled rectifier. This places a positive voltage from junction point 172 and lead 256 on the cathode of controlled rectifier 220 to prevent its conduction and, therefore, it also prevents actuation of the "reject" relay by energization of coil 208.
In the event that there is no validation or proper bill recognition from amplifier circuit 390, and no energization of "validate" relay coil 274, the "reject" relay coil 208 will be energized to effect bill return functions. Thus, if the bill passes around transport disc 50 (FIG. 2) and blocks the light from lamp 90 to photocell 104 without there having been a valid recognition and energization of "validate" relay coil 274, an increased positive voltage is applied to the gate electrode of controlled rectifier 220 to energize the "reject" relay coil 208. This energization redirects AC voltage from lead 190 and contact 276 through lead 288 which energizes the remaining drive coil side 290 of drive motor 34 such that it is energized to move in the reverse direction to back the paper bill back out of validating apparatus 10 and outward across the entry plate 22. The relay contact 264 is a holding contact which applies ground from lead 266 to the lead 260. Thus, the "reject" relay is held energized after extinction or ceasing of conduction through controlled rectifier 220. The "reject" relay coil 208 is deenergized only upon release of the "turn on" relay when the paper bill is removed and photocell 94 is once again illuminated by lamp 90. The "turn on" relay contact 186 only applies energization through lead 190, resistor 216 and rectifier 214 to the "validate" and "reject" relays when the "turn on" relay is energized.
A specific form of heater circuit 520 is shown in FIG. 6. The heater circuit 520 is energized between the AC lead 132 and common lead 136. A selected form of heater element 522 is connected through a rectifier 524 of the AC lead 132 while the other end of heater element 522 at a junction point 526 is connected to the anode of a controlled rectifier 528 having the cathode connected to common lead 136. A thermistor 530, selected for desired temperature range, is connected to a junction point 532 which, in turn, is connected in series with a resistor 534 to the gate electrode of controlled rectifier 528. A series-connected resistance 536 and capacitor 538 are connected between junction 532 and junction point 526 to provide holding of the controlled rectifier 528.
The heater circuit 520 can be employed with heater element 522 optimally placed within the validating apparatus 10 to provide heat distribution throughout the interior thereof. The heat circuit 520 then allows periodic conduction of current through the heater element 522 as the controlled rectifier 528 is periodically triggered when the thermistor 530 changes to a predetermined threshold state. The thermistor 530, as well as the heater element 522, will be selected in accordance with the required design characteristics and intended usage of the validating apparatus 10.
FIG. 7 illustrates an efficient heat-sensing circuitry 540 which guards against overheat conditions. The heat-sensing circuitry 540 employs a pair of thermistors 542 and 544 of selected temperature range which may be located at optimally sensitive points within the validating apparatus 10, e.g. one situated near drive motor 34 and the other situated near solenoid 78. A control relay 546 having normally open contacts 548 connected between common 136 and a junction 162 (FIG. 4). The relay 546 is energized from AC lead 132 through a resistor 550 and rectifier 552 with return being via a resistor 554 and a normally conducting controlled rectifier 556. The gate electrode of controlled rectifier 556 is connected through a resistor 558 to a first rectifier 560 leading to a first terminal point 562, and, in parallel, to a second rectifier 564 leading to a second terminal point 556. The terminal point 562 is a divider point between a resistor 568 and thermistor 544 which may be situated near the drive motor 34 (FIGS. 2 and 3), while the second voltage divider point 566 is formed between a resistor 570 and the thermistor 542 disposed adjacent solenoid 78 (FIG. 2). A series-connected capacitor 572 and resistor 574 are connected between the anode of controlled rectifier 556 and the DC lead of the cathode of rectifier 552. Thus, if either of thermistors 542 and 544 sense an overheat condition at their respective mounting positions, their resistance will be lessened to reduce the DC trigger voltage at the gate electrode of controlled rectifier 556 such that it is allowed to drop out of conduction to deenergize relay 546, thereby to short circuit the junction point 162 (FIG. 4) to the common or ground 136. Grounding of junction point 162 disallows the possibility of conduction of controlled rectifier 166 (FIG. 4) such that the "turn on" relay is disabled and no operation of the control circuitry 130 of validating apparatus 10 can take place.
FIG. 8 shows a similar form of heat-sensing circuitry where the normally conducting controlled rectifier 556 is connected directly in the cathode circuit of the controlled rectifier 166 (FIG. 4) which controls energization of the "turn on" relay. Thus, controlled rectifier 556 is normally conducting to allow conduction, when triggered, of the controlled rectifier 166 of the "turn on" circuit in control circuitry 130 (FIG. 4); however, sensing of the overheat condition of either of thermistors 542 and 544 reduces the positive voltage on the gate electrode of controlled rectifier 556 such that it will drop out of conduction to open the cathode circuit of controlled rectifier 166 (FIG. 4).
FIG. 9 is an alternative form of bill recognition device 580 which may be used in the validating apparatus 10. Advantages arising from recognition device 580 would merely be those of positioning, space saving, etc. The recognition device 580 is arranged to view a paper bill traveling along the path indicated by arrow 582 through an aperture 584. Light transmitted through the bill and aperture 584 is reflected from a 45° angle reflector 586 through an imaging lens 588 for projection on a suitable grid mask 590 for impingement on the photoconductive cell 592. The entire assembly is shown as being held by a rectangular casing 594; however, it should be understood that casing 594 may be a telescoping assembly which provides various focusing adjustments as between the photoconductive cell 592 and the imaging optics, i.e. lens 588 and reflector 586.
FIG. 10 shows still another alternative form of recognition device 600 which utilizes a somewhat reversed structure. That is, a lamp 602 supported a predetermined distance from bill path 604 by a barrel or casing 606, is mounted to project light through a lenticulated glass plate 608 whereupon the segmented light is projected through the bill to photo-optically affect a photoconductive cell 610. The lenticulated glass plate 608 actually provides the masking effect by dividing the projected light beam into a series of parallel light bands each to be individually focused at the face of the paper bill (path 604). The lenticulated plate may be formed by various well-known methods, i.e. engraving, etching, etc. The size and spacing of individual lenticulations is selected in accordance with the line pattern, number and spacing of lines which it is desired to include. In other words, the type and/or denomination of bill and bill matter to be used in recognition will dictate the lenticulation.
It should be understood that any one or all of the electromechanical switching components and elements alluded to in the prior description may be replaced by counterpart solid-state circuitry of well-known types. Substitution of solid-state devices for performance of the various relay switching devices is deemed to be well within the skills of the trained artisan.
The foregoing discloses novel bill-validating apparatus of reduced size and complexity which is capable of distinguishing validity characteristics with a very much increased probability of accuracy. The apparatus utilizes recognition concepts which reduce the possibilities of all known forms of piracy of such validation devices; that is, cheating the machine through counterfeits or attachments for withdrawing validated currency as well as various other forms of pirating technique are effectively combated by the present device. In addition, the apparatus has the attribute that there is a reduced chance that valid currency, even old or battered bills, will be wrongly returned without validation. In addition to these various advantages and the reduced size and complexity of each unit, the device embodies certain additional advantageous factors such as the switching system which only allows full equipment energization during times when a bill or document is inserted in the machine.
Changes may be made in the combination and arrangement of elements as heretofore set forth in this specification and shown in the drawings; it being understood, that changes may be made in the embodiments disclosed without departing from the spirit and scope of the invention as defined in the following claims.
The subject matter of the present application is particularly related to that invention subject matter contained in U.S. Pat. application Ser. No. 658,079 entitled "Bill Validating Apparatus" filed on Aug. 3, 1967 by the present inventor, now U.S. Pat. No. 3,481,464.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to document validation devices and, more particularly, but not by way of limitation, it relates to improved apparatus for readily ascertaining the validity of paper currency to selectively enable payout and/or coin-change apparatus.
2. Description of the Prior Art
The prior art includes various types of bill-validating apparatus which employ one or more of various types of sensing such as photoelectric, magnetic, thickness-testing conductivity, etc. There are various types of such equipments which tend to utilize photoelectric means alone, or such photoelectric means in combination with another form of detection, e.g. magnetic sensing. These devices function to a high degree of satisfaction and presently find employ in diverse fields. There still exist some shortcomings in operation of those types of device utilizing photoelectric cells due to various inherent factors present within the photoelectric or photoconductive cells utilized. Such factors are generally those which necessitate combination of photoelectric operation with another form or mode of bill characteristic detection.
SUMMARY OF THE INVENTION
The present invention contemplates bill validation apparatus utilizing photoelectric detection means to examine a document or paper bill for a selected physical characteristic, thereafter to escrow or return the bill or document in accordance with the finding. The invention includes a transport means for receiving and carrying a bill or document to be examined whereupon the bill is moved at a predetermined rate past a photoelectric sensing station to check for validity while additional photoelectric means are utilized to signify bill presence and position of traverse along the transport path. Control means functioning in response to validity finding of the bill by the sensor means controls the transport means to deliver the bill to escrow; or, if invalid, to return it backward out to the point of entry. The invention utilizes a particular form of bill characteristic sensing as it photoelectrically inspects grid or line portions of bill printing to derive a sense indication dependent upon proper line spacing, a photoelectric sense reading is applied to an amplifier which provides an output indicative of the required line or grid periodicity.
Therefore, it is an object of the present invention to provide an improved bill-validating device which is more compact in size and more reliable in detection.
It is also an object of the invention to substitute photoelectric devices for mechanical control switching thereby to provide increased reliability at lower cost of manufacture.
It is still another object of the invention to provide bill detection apparatus which may utilize a single bill characteristic sensing device of the photoelectric type with a high degree of accuracy and reliability.
Finally, it is an object of the present invention to provide a bill-validating device which is uniformly small, lightweight and applicable to diverse bill-changing requirements, and which is highly reliable and offering increased resistance to all known piracy techniques.
Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawings which illustrate the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of validating apparatus constructed in accordance with the present invention;
FIG. 2 is a vertical section taken along lines 2-2 of FIG. 1;
FIG. 3 is a partial section of validating apparatus of FIG. 1 as taken along lines 3-3;
FIG. 4 is a schematic diagram of the control circuitry of the validating apparatus of FIG. 1;
FIG. 5 is a schematic diagram of amplifier circuitry which is employed in the validating apparatus of FIG. 1;
FIG. 6 is a form of heater circuit which may be employed in the control circuitry of FIG. 4;
FIG. 7 is a form of heat control circuit which may be employed in the control circuitry of FIG. 4;
FIG. 8 is an alternative form of heat control circuit which may be employed in the control circuitry of FIG. 4;
FIG. 9 depicts in vertical section an alternative design for a bill-sensing device to be utilized in the validating apparatus; and
FIG. 10 is a figurative illustration of still another form of bill characteristic sensing device which may be utilized.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a bill-validating apparatus 10 consists of a frame member 12, a rectangularly bent metal frame, having opposite side panels 14 and 16 (not shown) which are suitably secured thereon in removable manner. A front opening 18 is provided through a front panel 20 of frame 12 to accommodate bill reception through a bill-receiving tray 22 having respective left and right side panels 24 and 26 and being securely affixed in an entry position.
Referring now to FIG. 2, the interior of validating apparatus 10 includes a plurality of electronic components 28 mounted in operative relationship on a circuit board 30 which, in turn, is mounted by suitable insulative mounting means (not specifically shown) inside of rear panel 32 of rectangular frame 12. A drive motor 34 including a suitable reduction gearbox 36 is mounted on the side panel 16 to support a rotary drive shaft 38 and drive pulley 40 in proper operative relationship as will be described. Although a matter of choice, the drive motor 34 and selected gearbox 36 may be separate, commercially available items; however, as shown in FIG. 2, the motor 34 and gearbox 36 may be obtained as an integral unit having selected power requirements and predetermined drive output speed and torque. Thus, the motor 34 may be a conventional capacitor run AC motor which may be selected from various commercially available types. In some applicants it may also be desirable to employ a reversible, shaded pole motor or well-known design.
The drive pulley 48 is in engagement with a transport belt 42 which may be the toothed, nonslip variety as shown. The transport belt 42 is positioned by idler pulleys 44 and 46 and tension pulley 48 so that it will contact around about one-half of the circumference of a transport disc 50. The transport disc 50 is rotatable on a shaft 62 and should be formed of relatively smooth material so that a paper bill or such can be held around its circumference beneath transport belt 42. The thickness of transport disc 50 is not critical; however, one form of the invention maintains the transport disc 50 at the same thickness as the width of transport belt 42, i.e. about three-eighths inch.
Referring also to FIG. 3, a pair of arcuate slide plates 52 and 54 located on the near and far side respectively of transport disc 50, are rigidly secured approximate the entry access hole 18 to serve as side guides for an inserted paper bill. Thus, the arcuate side guides 52 and 54 may each be formed integrally with the entry plate 22, the entire piece being rigidly secured by suitable fastening techniques such as a plate 56 secured by a bracket 58. A bracket 60 secured as by spot welding to side guide 52 may be supported on the positioning shaft 62 which is securely journaled between opposite side panels 14 and 16 of validating apparatus 10, and which also serves to maintain the transport disc 50 in operative position. A similar bracket (not shown) would support side guide 54 on the further side of transport disc 50.
The idler pulleys 44 and 46 are suitable supported on respective shafts 64 and 66 and tension pulley 48 is similarly supported in rotational manner on a shaft 68. The shafts 64, 66 and 68 may also be suspended in rigid manner between suitable journal affixures on the respective side panels 14 and 16. A tension bar 70 is supported by a pair of side brackets 72 (the near one not being shown) which are pivotally affixed about a journaled shaft 74. A pair of tension springs 74 (the near one again not being shown) such that tension bar 70 is urged upward about pivot axis or shaft 74. A solenoid 78 is mounted on side panel 16 and positioned to extend armature 80 into pivotal contact with shaft 64. The bracket plate 69 is formed with an angularly shaped lower edge 82 which coacts with a knife plate 84 suspended by a flange connection 86 for movement with bracket plates 69 and axle 64 about the pivot shaft 68. Thus, upon actuation of the solenoid 78 as will be further described below, bracket plate 69 is urged leftward, (relative to FIG. 3) and lower edge 82 of bracket plate 69 bears against a suitable spacer or roller 88 to force the pivotal brackets 72 downward, this allowing a bill passage spacing between knife plate 84 and roller 88. The knife plate 84 in its relaxed state tends to hold a bill against roller 88 to prevent piratelike removal back along the transport route as by a thread attachment or such.
A plurality of photocells are employed to perform various function actuations within the validating apparatus 10. Thus, a lamp 90 is mounted so that it can be viewed through an entry aperture 92 in entry plate 22 by an entrance photocell 94 which is held by means of a suitable supporting tube 96 and bracket 98 attached to a securing post 100. A second photocell 102, a light burnout or safety photocell is mounted directly below lamp 90 in viewing relationship thereto. Still an additional photocell 104, the reject and "hold on" photocell, and photocell 106, the "turnoff" photocell, are each supported on opposite sides of a bracket 108 which is secured in keyed manner on shaft 68 so that photocells 104 and 106 continually view the lamp 90.
The bill-verifying photoconductive cell 110 is retained within a barrel 112 which is supported by a suitable bracket 114 suspended from securing post 100 as can be seen to best advantage in FIG. 3. Thus, the photoconductive cell 110 is held by barrel 112 for viewing through a hole 116 in arcuate slide plate 54 to a bill-verifying light source, a lamp 118, as supported by bracket 120 affixed to transverse shaft 62.
The barrel 12 includes the photoconductive cell 110 at its upper end with a selected grid or mask 122 disposed across the interior of the barrel at a selected midpoint which provides proper focal registration. The mask 122 is a selected line structure which should provide a selected moire effect upon comparison with a particular line structure of ink printing on the document to be examined. Thus, in the case of examination of portrait background on a 1 dollar bill, a line structure of about 120 lines per inch will provide the proper grid function or moire effect as relied upon in the electronics, to be further described below. This line structure will vary with different denominations of paper money or with any other pattern for which the device may be utilized in recognition. An objective lens 124 is disposed across barrel 112 at a distance which will provide proper focus as between a bill or document disposed on arcuate slide plate 54 and the image plane at mask 122. It is contemplated that barrel 112 be of sectional construction to enable various sliding adjustments as to focus and imaging of the recognition structure.
Referring now to FIG. 4, control circuitry 130 provides actuation control for the bill validation apparatus 10. AC line voltage is applied in between a high side lead 132 and a lead 134 which may be connected directly to a common lead 136. The bill inspection lamp 118, e.g. a 110-volt AC, 6-watt lamp bulb, is connected directly across the AC line between lead 132 and common lead 136.
A voltage-dropping resistor 138 is connected between AC lead 132 and a rectifier 140 which provides half-wave DC voltage at junction point 142, which DC voltage is employed for various functions to be further described. The light burnout or safety photocell 102 is connected between junction 142 and a junction 144 which is connected via lead 146 and a resistor 148 to common 136. Junction point 144 is further connected to a resistor 150 in series with a junction 152 and the entrance photocell 94 to common 136. A lead 154 is connected from junction 142 to a coil 156 of the "turn on" relay.
A neon lamp 158 in series with a resistor 160 is connected between the junction point 152 and a junction point 162 which is further connected through a resistor 164 to the gate electrode of a semiconductive controlled rectifier 166. The junction point 162 is connected through a thermal conduction device 168, a thermistor or other such heat-regulating device (as will be further described), to the common lead 136, as well as through a resistor 170 junction 172 and a dropping resistor 174 to the DC supply lead 154. A control diode 176 is then connected between junction 144 and the junction 172 to provide isolation relative to the light burnout photocell 102 to insure that the circuitry is completely disabled when lamp 90 burns out.
The relay coil 156 has one end connected to the DC half-wave supply on lead 154 while the other end is connected through a voltage-dropping resistor 178 to the anode of the controlled rectifier 166. A capacitor 180 and resistor 182 are connected in series across relay coil 156 to provide the necessary damping upon energization of the "turn on" relay coil 156. The cathode of control rectifier 166 is connected directly to common 136. The relay coil 156 actuates wiper contacts 184 and 186 to apply voltage energization to the remainder of the control circuitry 130. Thus, wiper contact 186 is connected to the AC lead 132 and, when relay coil 156 is energized, wiper contact 186 makes with contact 188 and a lead 190 which conveys AC voltage to various additional circuit components. The wiper contact 184 applies rectified DC via lead 192. Contact 184 connection in the normal position is through contact 194 to a lead 196 through a resistor 198 to a grounded or common junction point 200, and in the energized position, the conduction is via contact 202 to a rectifier 204 and resistor 206 which, is energized from the AC lead 190.
A "reject" relay is controlled by a relay coil 208 which is energized via a lead 210 from a junction point 212 energized by a rectifier 214. The rectifier 214 and a dropping resistor 216 are connected back to the AC lead 190 which is enabled by energization of the "turn on" relay coil 156. The "reject" relay coil 208 is connected through a resistor 218 to the anode of a control rectifier 220 and a capacitor 222 in series with the resistor 224 is connected across the relay coil 208. The gate electrode of controlled rectifier 220 is connected through a resistor 226 and diode 228 to a junction point 230. A neon lamp 232 is connected between junction point 230 and a junction point 234 while junction point 234 is biased above common by the "hold on" photocell 104. Junction point 234 is connected back to junction point 144 through a resistor 235 by means of a lead 236.
The junction point 230 is also connected through a diode 238 to a junction point 240 which is shorted to the junction point 162 in the "turn on" circuit. The junction point 240 is also connected in series through a resistor 242 and series-connected diodes 244 and 246 to common. A capacitor 248 conducts control input from photocell 106 as energized by DC voltage from 250 and series resistor 252.
The cathode of controlled rectifier 220 is connected via a lead 256 back to a point of DC reference at junction point 172. The cathode of controlled rectifier 220 is also connected via lead 258 to a connection which is normally grounded prior to validation output as will be further described. A lead 260 provides holding contact from the anode of controlled rectifier 220 back to the "reject" contact 262 which, upon energization, makes through wiper contact 264 and lead 266 to common. In its normal position, wiper contact 264 makes with contact 268 to maintain ground potential on a lead 270 that is connected to the cathode of a controlled rectifier 272 which controls the "validate" relay coil 274. The "reject" relay coil 208 also controls application of the AC supply lead 190 through wiper contact 276 to the drive motor 34.
Thus, in its normal or deenergized position, contact 278 applies AC voltage via lead 280 to one side 282 of the motor-energizing coil 284. In its energized position, wiper contact 276 makes with a contact 286 to apply AC voltage via lead 288 to the remaining side 290 of energizing coil 284. A center tap 292 is connected via lead 294 through lamp 90 to common 136. A pair of Zener diodes 296 and 298 of selected rating are connected series-opposed across lamp 90 to maintain a 6 volt DC energizing source for the DC lamp 90.
A running capacitor 300 is connected across motor-energizing winding 284 in shunt. An additional motor winding 302 may be optionally included for the purpose of providing an isolation output across terminals 304 and 306. This would amount to a space-saving measure where the motor-energizing coil 284 is employed as a transformer primary while secondary coil 302 derives an AC output for use in energizing the remainder of the circuitry. This is particularly attractive for the purpose of providing isolation between the AC line and the control circuitry 130 for safety purposes. It should be understood too that there are other commercially available forms of reversible AC motor which can be employed in the present invention with little or no application variations.
The "validate" relay coil 274 is connected between the DC junction point 212 and the anode of controlled rectifier 272. The capacitor 308 and resistor 310 are connected across relay coil 274 and in parallel with a current-limiting resistor 312 while a lead 314 provides a relay holding connection. The gate electrode of control rectifier 272 is connected through a capacitor 317 to the normally grounded lead 270 and also through the wiper element of a potentiometer 318 connected between normally grounded lead 270 and a resistor 320 leading to a control input 322 which is connected to a validation amplifier (FIG. 5) as will be further described in detail. Positive going signal input at amplifier input 322 causes controlled rectifier 272 to conduct to energize the "validate" relay coil 274.
When relay coil 274 is energized, a wiper contact 324 applies AC voltage from lead 132 to a contact 326 which connects to lead 328 supplying AC voltage to the solenoid 78. A second wiper contact 330, connected via lead 332 to a voltage storage capacitor 334, breaks connection with a contact 336 and lead 338 to one side of a "payout" relay coil 340. Also when coil 274 is energized, wiper contact 330 makes with contact 342 to a lead 344, a DC source from a rectifier 346 and dropping resistor 348 connected in series from lead 192. Still further, a third wiper contact 350 breaks a connection through contact 352 and lead 354 to the cathode of controlled rectifier 220, the "reject" controlled rectifier, to make with a relay contact 356 and the relay hold lead 314.
A lead 360 connects the remaining side of "payout" relay 340 to ground such that its energization depends from wiper contact 330 of the "validate" relay. The "payout" relay coil 340 energizes a single, normally open wiper contact 362 into contact with a normally open contact 364 to short circuit leads 366 and 368 to provide a validity output signal to an external payout circuit. The external payout circuit may be any of the conventional bill, ticket, coin, etc. dispensing mechanisms which might be employed with the particular bill-validating apparatus 10. DC voltage for use throughout the system is generated upon energization of the "turn on" relay coil 156. Thus, wiper contact 184 mates with contact 202 which, through the action of rectifier 204 connected back to AC source lead 190, provides DC voltage via lead 192 which is available at a junction point 370. The DC voltage 370 is available on a lead 372 for output at a DC 1 terminal 374, adequate filtering being effected by a capacitor 376 connected to ground or common 136. A reduced value of DC is present at DC 2 terminal point 378 as derived via lead 380 from junction point 382. A dropping resistor 384 is connected between terminal point 370 and terminal point 382, and additional capacitor filtering is provided by a capacitor 386 connected between terminal point 382 and common 136.
Referring now to FIG. 5, an amplifier 390 is energized by DC 2 voltage at input terminal 379, DC 1 voltage at input terminal 375 and AC line voltage at an input terminal 392. The validity recognition photocell 110, as shown also in FIG. 2, is connected between common lead 394 and a junction point 396 which is energized by a potential determined by a voltage-dropping resistor 398 connected to the DC 2 input source 379. Input voltage variation at junction point 396 is applied through a coupling capacitor 400 to the base of an NPN-type transistor 402 having its emitter connected directly to common lead 394. The collector of transistor 402 is connected through a load resistor 404 to a DC supply lead 406 which is energized through an additional series load resistor 408 connected to the DC 1 voltage source 375. A Zener diode 409 connected between lead 406 and common provides voltage regulation. A biasing resistor 410 and parallel-connected feedback capacitor 412 connected between the collector and base of transistor 402 serve to effect neutralization by providing degenerative feedback.
The output from transistor 402 is taken from the collector for application through a coupling capacitor 414 to the base of an emitter-grounded, NPN-type transistor 416. Amplification is effected by serial amplification in a cascade of transistor amplifier stages of similar configuration. Thus, in the manner of emitter-grounded connection of transistor 402, each of NPN-type transistors 416, 418, 420 and 422 are similarly connected for energization through the respective parallel load resistors 424, 426, 428 and 430, as interconnecting output signal coupling is effected by coupling capacitors 432, 434, 436 and 438, respectively. Collector-base neutralization and biasing for each amplifier stage is effected by the respective degenerative feedback networks, resistance-capacitance networks 440, 442, 444 and 446.
A final amplifier output is conducted through capacitor 438 for application to an output doubler circuit consisting of grounded diode 448 and serial diode 450 which charges storage capacitor 452. Charge buildup on capacitor 452 is conducted through a resistor 454 for application to the base of NPN-type transistor 456 which provides emitter output via amplifier output lead 458, i.e. input 322 to the control circuitry 130 (FIG. 4). In the case of a single validation channel, a single transistor 456 is employed with DC energization effected through bypass lead 460 (dash line) connected to the DC voltage source lead 406. In the event that a second validation channel input is employed, the input 462 is applied to a second serial transistor stage 464 through a base resistor 466. The addition of extra validation input channels is a matter of choice depending upon design exigencies and, in any event, a filter capacitor 468 is connected between the voltage supply lead 406 and common lead 394.
An accessory circuit, a density regulation circuit 470, may also be included in the amplifier circuitry 390 to further refine the operation and increase the capabilities of the validation device. The density circuit 470 is energized by the DC potential lead 406 as applied across a network including density-reading photocells 472 and 474. Density reading photocell 472 is connected between the DC source lead 406 and a junction point 476, and a potentiometer 478 is connected between point 476 and common lead 394. In opposite disposition, a density photocell 474 is connected between common lead 394 and a junction point 480 whereupon a potentiometer 482 is connected between junction point 480 and the DC source lead 406.
Junction point 476 is connected through a diode 484 to a junction point 486 while junction point 480 is connected in parallel through a diode 488. Junction point 486 constitutes the input through a dropping resistor 490 to the base of an NPN-type transistor 492 which is connected common-emitter as it has the collector lead 494 coupled directly to the base of output transistor 456. Thus, diodes 484 and 488 constitute an OR gate input-controlling transistor 492 which, in turn, controls conduction of transistor 456 to provide the amplifier output. The density-reading photocells 472 and 474 are so connected that either an undue dark reading at photocell 474 or an undue light reading at photo cell 472 will actuate through the respective OR gate diodes 488 and 484 to energize transistor 492 so that output transistor 456 is blocked to cancel any signal output on amplifier output lead 458.
Additional OR gate inputs to the base of transistor 492 are coupled through diodes 496 and 498. The diode 498 receives signal input from the 110-volt AC line at input 392 as conducted through a capacitor 500 biased above ground by a resistor 502. AC signal at a junction point 504 is full-wave rectified and doubled by diodes 506 and 508 for input through diode 498. A capacitance 510 and parallel-connected resistor 512 are connected between the anode of diode 498 and common lead 394. The DC 2 voltage at input terminal 379 is applied through a capacitor 514 to a terminal 516 and DC return is provided through a resistor 518. The voltage variations at junction point 516 are applied to the anode of diode 496. Thus, diodes 496 and 498 constitute further OR inputs to the base of control transistor 492.
OPERATION
The validating apparatus 10 can be employed in various types of coin-change, laundry operation, and dispensing machines to mention only a few possible applications. Each validating apparatus 10 is first preadjusted for its particular application. Thus, the recognition optics within the barrel 112 must be adjusted for proper focus and line masking. The mask 122 is selected to have a line pattern which will exhibit a desired moire effect with a certain denomination of paper money. As previously mentioned, if recognition requires a view of the portrait background on a 1 dollar bill, the line structure of about 120 lines per inch, 50 percent open, will provide the proper grid function. The barrel 112 and objective lens 124 are also adjusted to provide most accurate imaging at the plane of the mask 122.
In its standby state there is no AC voltage distributed throughout the validating apparatus 10. Entry of a paper currency bill on entry plate 22 will block the entry aperture 92 such that illumination from lamp 90 is removed from view of the entrance of photocell 94. As shown in FIG. 4, darkening of photocell 94 increases its resistance such that the voltage increase at terminal point 152 is reflected to terminal point 162 and the increase in positive voltage is received at the gate electrode of semiconductive control rectifier 166 to trigger it into conduction. The conduction permits maximum current flow from positive voltage junction point 142 through the "turn on" relay coil 156, thereby to energize the "turn on" relay. The energization closes relay contacts 186 and 184 to their energized positions whereupon AC line energization from the lead 132 is applied via a lead 190 for distribution to energize the circuitry throughout the validating apparatus 10. A DC potential as derived from AC lead 190 through rectifier 204 is available on lead 192 for application variously as will be described below. The AC energization on lead 190 is applied through the "reject" relay contact 276 (normal position) for conduction via lead 280 to energize drive motor 34 in its forward rotation. Thus, the paper bill which was previously introduced on entry plate 22 will be gripped by the moving transport belt 42 and carried up around arcuate guide plates 52, 54 and the transport disc 50.
The paper bill is moved at a constant rate around transport disc 50 by means of transport belt 42, and positioning is such that a selected line-grid portion of the bill print, e.g. portrait background, is maintained in viewing relationship to the barrel 112 holding the recognition optics. Thus, as shown in FIG. 3, the selected portion of the bill will pass over aperture 116 to receive light transmission from lamp 118 for inspection by mask 122 and photocell 110.
The photocell 110, e.g. a cadmium sulfide photoconductive element, exhibits change in resistance with a change in light and it is affected by a moire effect pattern as the combined light from the bill print structure and mask 122 is projected on the sensitive surface of photocell 110. If there is in fact proper portrait background, i.e. the proper number and spacing of lines and spaces, the resistance of photocell 110 will be changed at a predetermined frequency which is distinguished by the amplifier circuitry 390 (FIG. 5) as being a proper or valid background recognition. The amplifier circuitry 390 is energized by the proper frequency input from photocell 110 to provide an amplified output via lead 458 which is then employed to actuate the "validate" relay in control circuitry 130 (FIG. 4) as will be further described.
A recognition input from varying resistance of photocell 110 is applied from terminal point 396 through coupling capacitor 400 for serial amplification in the respective cascaded amplifiers, transistors 402, 416, 418, 420 and 422. The resistor 398 and coupling capacitor 400, as considered with the resistance of photocell 110, are selected values which contribute to the desired frequency response, i.e. a pass band on the order of 300 to 400 cycles which is effectively an open circuit below 120 cycles. Amplified output from the final amplifier transistor 422 is applied through a coupling capacitor 438 and then doubled for application to the base of an output transistor 456. Emitter output from transistor 456 is then applied via lead 458 for input to the amplifier input 322 of control circuitry 130 in FIG. 5. The transistor 456 may be coupled for energization as by dashline 460; or, a second output transistor 464 may be connected in series to provide output in response to energization by a second recognition channel input at input 462. Such second channel input 462 may receive signal from a concurrently employed sensor of well-known type e.g. magnetic sensing, pierce-test sensing, other photoelectric sensing devices, etc.
The essential operation of amplifier circuitry 390 is complete as set forth above, but it may be further enhanced by the inclusion of sensity test photocells which provide further validation as to the type or density of the paper material. Thus, photocells 472 and 474 may be suitably disposed within validating apparatus 10 (FIGS. 2 and 3) in a position whereby they view the light source 90, the position being such that the bill being tested will pass between lamp 118 (or other validating lamp) and photocells 472 and 474 during the validation function. The potentiometers 478 and 382 may be preadjusted to set a threshold and upper limit, respectively, of energization as derived from light passing through the paper material of the currency. Thus, if not enough light is seen by photocell 474, the voltage at terminal 480 is increased to cause conduction of transistors 492 such that the base of amplifier output transistor 456 is effectively grounded and cut off so that no validating output can be conducted. On the other hand, if greater than a predetermined amount of light is present and detected by photocell 472 the voltage at terminal 476 is raised above a predetermined threshold setting, and this too will bring about conduction of transistor 492 to ground the base of transistor 456 and block amplifier output via lead 458.
Further blocking inputs may be received through the OR gate diodes 496 and 498. The diode 496 is connected to terminal 516 and input capacitor 514 from the DC 2 source 379 to provide blocking of amplifier output transistor 456 when the unit is first turned on. That is, input through diode 496 will hold transistor 492 in conduction until the control circuitry 130 warms up or reaches its stable operating level throughout the circuitry. The diode 498 provides blocking of amplifier output transistor 456 in the event that line transient voltages, e.g. motor brush transients, inductive kickback voltage fluctuations, etc., are present on the AC line to the validating assembly 10.
Referring again to FIG. 4, a signal representative of a valid recognition may be received at input 322 whereupon it is applied to gate electrode of the semiconductive control rectifier 272 to cause conduction and energize the coil 274 of the "validate" relay. The energized "validate" relay applies AC from lead 132 to contact 324 to a lead 328 which energizes the solenoid 78 (see also FIGS. 2 and 3). Solenoid 78 serves to move idler pulley 46 and, therefore, the lower portion of transport belt 42 into position to guide the valid bill into an escrow compartment associated with validating apparatus 10. Also, it operates to position the knife plate 84 to prevent cheating by withdrawal of the bill after payout actuation.
The "validate" relay contact 330 is closed to apply DC voltage from rectifier 346 and lead 344 through a lead 332 to charge up a capacitor 334 which is connected to the grounded junction point 200. Thus, upon release of the "validate" relay to its normal contact position, lead 332 is connected through contact 330 to contact 336 and lead 338 to apply the stored electrical charge from capacitor 334 across "payout" relay coil 340 to energize it sufficiently to provide a circuit-closure actuation as between external payout circuit leads 366 and 368. The charge from capacitor 334 is merely a pulse sufficient to momentarily actuate the "payout" relay coil 340.
Still a further function of the "validate" relay is to disconnect the grounded relay contact 350 from contact 352 which connects via lead 258 to the cathode of the controlled rectifier 220, the "reject" actuator controlled rectifier. This places a positive voltage from junction point 172 and lead 256 on the cathode of controlled rectifier 220 to prevent its conduction and, therefore, it also prevents actuation of the "reject" relay by energization of coil 208.
In the event that there is no validation or proper bill recognition from amplifier circuit 390, and no energization of "validate" relay coil 274, the "reject" relay coil 208 will be energized to effect bill return functions. Thus, if the bill passes around transport disc 50 (FIG. 2) and blocks the light from lamp 90 to photocell 104 without there having been a valid recognition and energization of "validate" relay coil 274, an increased positive voltage is applied to the gate electrode of controlled rectifier 220 to energize the "reject" relay coil 208. This energization redirects AC voltage from lead 190 and contact 276 through lead 288 which energizes the remaining drive coil side 290 of drive motor 34 such that it is energized to move in the reverse direction to back the paper bill back out of validating apparatus 10 and outward across the entry plate 22. The relay contact 264 is a holding contact which applies ground from lead 266 to the lead 260. Thus, the "reject" relay is held energized after extinction or ceasing of conduction through controlled rectifier 220. The "reject" relay coil 208 is deenergized only upon release of the "turn on" relay when the paper bill is removed and photocell 94 is once again illuminated by lamp 90. The "turn on" relay contact 186 only applies energization through lead 190, resistor 216 and rectifier 214 to the "validate" and "reject" relays when the "turn on" relay is energized.
A specific form of heater circuit 520 is shown in FIG. 6. The heater circuit 520 is energized between the AC lead 132 and common lead 136. A selected form of heater element 522 is connected through a rectifier 524 of the AC lead 132 while the other end of heater element 522 at a junction point 526 is connected to the anode of a controlled rectifier 528 having the cathode connected to common lead 136. A thermistor 530, selected for desired temperature range, is connected to a junction point 532 which, in turn, is connected in series with a resistor 534 to the gate electrode of controlled rectifier 528. A series-connected resistance 536 and capacitor 538 are connected between junction 532 and junction point 526 to provide holding of the controlled rectifier 528.
The heater circuit 520 can be employed with heater element 522 optimally placed within the validating apparatus 10 to provide heat distribution throughout the interior thereof. The heat circuit 520 then allows periodic conduction of current through the heater element 522 as the controlled rectifier 528 is periodically triggered when the thermistor 530 changes to a predetermined threshold state. The thermistor 530, as well as the heater element 522, will be selected in accordance with the required design characteristics and intended usage of the validating apparatus 10.
FIG. 7 illustrates an efficient heat-sensing circuitry 540 which guards against overheat conditions. The heat-sensing circuitry 540 employs a pair of thermistors 542 and 544 of selected temperature range which may be located at optimally sensitive points within the validating apparatus 10, e.g. one situated near drive motor 34 and the other situated near solenoid 78. A control relay 546 having normally open contacts 548 connected between common 136 and a junction 162 (FIG. 4). The relay 546 is energized from AC lead 132 through a resistor 550 and rectifier 552 with return being via a resistor 554 and a normally conducting controlled rectifier 556. The gate electrode of controlled rectifier 556 is connected through a resistor 558 to a first rectifier 560 leading to a first terminal point 562, and, in parallel, to a second rectifier 564 leading to a second terminal point 556. The terminal point 562 is a divider point between a resistor 568 and thermistor 544 which may be situated near the drive motor 34 (FIGS. 2 and 3), while the second voltage divider point 566 is formed between a resistor 570 and the thermistor 542 disposed adjacent solenoid 78 (FIG. 2). A series-connected capacitor 572 and resistor 574 are connected between the anode of controlled rectifier 556 and the DC lead of the cathode of rectifier 552. Thus, if either of thermistors 542 and 544 sense an overheat condition at their respective mounting positions, their resistance will be lessened to reduce the DC trigger voltage at the gate electrode of controlled rectifier 556 such that it is allowed to drop out of conduction to deenergize relay 546, thereby to short circuit the junction point 162 (FIG. 4) to the common or ground 136. Grounding of junction point 162 disallows the possibility of conduction of controlled rectifier 166 (FIG. 4) such that the "turn on" relay is disabled and no operation of the control circuitry 130 of validating apparatus 10 can take place.
FIG. 8 shows a similar form of heat-sensing circuitry where the normally conducting controlled rectifier 556 is connected directly in the cathode circuit of the controlled rectifier 166 (FIG. 4) which controls energization of the "turn on" relay. Thus, controlled rectifier 556 is normally conducting to allow conduction, when triggered, of the controlled rectifier 166 of the "turn on" circuit in control circuitry 130 (FIG. 4); however, sensing of the overheat condition of either of thermistors 542 and 544 reduces the positive voltage on the gate electrode of controlled rectifier 556 such that it will drop out of conduction to open the cathode circuit of controlled rectifier 166 (FIG. 4).
FIG. 9 is an alternative form of bill recognition device 580 which may be used in the validating apparatus 10. Advantages arising from recognition device 580 would merely be those of positioning, space saving, etc. The recognition device 580 is arranged to view a paper bill traveling along the path indicated by arrow 582 through an aperture 584. Light transmitted through the bill and aperture 584 is reflected from a 45° angle reflector 586 through an imaging lens 588 for projection on a suitable grid mask 590 for impingement on the photoconductive cell 592. The entire assembly is shown as being held by a rectangular casing 594; however, it should be understood that casing 594 may be a telescoping assembly which provides various focusing adjustments as between the photoconductive cell 592 and the imaging optics, i.e. lens 588 and reflector 586.
FIG. 10 shows still another alternative form of recognition device 600 which utilizes a somewhat reversed structure. That is, a lamp 602 supported a predetermined distance from bill path 604 by a barrel or casing 606, is mounted to project light through a lenticulated glass plate 608 whereupon the segmented light is projected through the bill to photo-optically affect a photoconductive cell 610. The lenticulated glass plate 608 actually provides the masking effect by dividing the projected light beam into a series of parallel light bands each to be individually focused at the face of the paper bill (path 604). The lenticulated plate may be formed by various well-known methods, i.e. engraving, etching, etc. The size and spacing of individual lenticulations is selected in accordance with the line pattern, number and spacing of lines which it is desired to include. In other words, the type and/or denomination of bill and bill matter to be used in recognition will dictate the lenticulation.
It should be understood that any one or all of the electromechanical switching components and elements alluded to in the prior description may be replaced by counterpart solid-state circuitry of well-known types. Substitution of solid-state devices for performance of the various relay switching devices is deemed to be well within the skills of the trained artisan.
The foregoing discloses novel bill-validating apparatus of reduced size and complexity which is capable of distinguishing validity characteristics with a very much increased probability of accuracy. The apparatus utilizes recognition concepts which reduce the possibilities of all known forms of piracy of such validation devices; that is, cheating the machine through counterfeits or attachments for withdrawing validated currency as well as various other forms of pirating technique are effectively combated by the present device. In addition, the apparatus has the attribute that there is a reduced chance that valid currency, even old or battered bills, will be wrongly returned without validation. In addition to these various advantages and the reduced size and complexity of each unit, the device embodies certain additional advantageous factors such as the switching system which only allows full equipment energization during times when a bill or document is inserted in the machine.
Changes may be made in the combination and arrangement of elements as heretofore set forth in this specification and shown in the drawings; it being understood, that changes may be made in the embodiments disclosed without departing from the spirit and scope of the invention as defined in the following claims.