Title:
Means and method for converting speech into visible indicia
United States Patent 2137888


Abstract:
This invention relates to a method and means for analysing the wave forms of spoken sounds and for causing those spoken sounds to make a visible Indication. The latter may be in the form of an illuminated letter, symbol, or word sign, or on the other hand may be in the form of a permanent printed...



Inventors:
Fuller, Wallace Watt J.
Application Number:
US5045635A
Publication Date:
11/22/1938
Filing Date:
11/18/1935
Assignee:
Fuller, Wallace Watt J.
Primary Class:
Other Classes:
178/31, 313/410, 324/76.26, 400/86, 434/112
International Classes:
G10L21/06
View Patent Images:



Description:

This invention relates to a method and means for analysing the wave forms of spoken sounds and for causing those spoken sounds to make a visible Indication. The latter may be in the form of an illuminated letter, symbol, or word sign, or on the other hand may be in the form of a permanent printed record.

It is a well known fact that speech is a complex phenomenon of pitch or frequency differences; volume, intensity or amplitude differences; and quality or number and relative strength of partials or harmonics or wave form differences. In the sense of hearing, all three of these components, and the duration or time element of each, are utilized for articulation or intelligibility.

It is an object of the present invention to provide a method and apparatus for converting inLelligible sounds (primarily speech sounds) into Intelligible visible indicia and, in accordance with this invention, I take into account all of the above mentioned factors, whereas, in the prior art, as far as I am aware, only the matter of frequency differences has been considered. For this reason, no operative method of, or apparatus for converting speech sounds into intelligible visible indicia have been produced, prior to my invention.

It is the primary object of the present invention, therefore, to provide a method and means for converting sounds into intelligible visible form, such as word signs, letters or characters, either exhibited, illuminated or printed.

It is an object of the invention to provide a method and apparatus which will make possible the conversion of speech sound into visible form, for instance, to enable totally deaf persons to understand, visually, the spoken word. The Invention, of course, is not confined to use by the deaf, as it is of utility in converting speech into a permanent printed record.

According to the pinciple of this invention, speech sounds or the like are first converted into a corresponding pulsating current, for instance, by the use of a microphone, a series of filters, and an audio-frequency amplifier. This current, and an appropriate sweep circuit, control the electron beam to trace a path corresponding to the spoken sound. As is well understood, either electro-magnetic or electro-static means, that is, coils or plates, respectively, or a combination :o of both may be used to control deflection. The voice current circuit may be connected to one pair of electron beam deflecting plates or coils of the cathode ray tube, and the other pair of plates or coils associated therewith may be connected either to a signal synchrontrzd sweep circult, or to a signal released, single stroke sweep circuit, as preferred.

Instead of using a conventional cathode ray tube, in which the electron beam is projected directly onto a fluorescent screen, merely for a the purpose of Illuminating the same, a special type of target is provided in my invention. The target is associated with the cathode ray tube, in the path of the. electron beam, and comprises essentially a mask provided with apertures of novel type, as explained below, and means behind the mask adapted to be affected by the beam projecting through one or more of the apertures.

The mask is provided with apertures positioned thereon in accordance with a plurality of different patterns, each pattern corresponding to the wave form or path traced thereon by the electron beam when actuated or controlled by a particular previously recorded sound. Each sound adapted to be indicated visually by the method and apparatus of the present invention will, of course, cause the electron beam to trace a different wave form on the mask. These curves may be traced before hand by the use of oil covered photographic plate or by the discoloring of the metal of the mask by the electron beam. One or more apertures may then be drilled or otherwise formed at convenient pointa along each curve, care being taken to avoid forming the apertures where the different sound traces cross 80 one another, and to avoid too close a spacing of the apertures. For each sound trace, a different position, number, size, or shape of apertures are provided.

When the electron beam is actuated and controlled by a predetermined sound, it will necessarily travel along the path prevloiWly recorded on the mask by a corresponding sound and will be projected through the aperture or apertures positioned on that path, but through no other apertures.

Since, as stated, the position, number, size or shape of the apertures are different, the effect of the beam projected therethrough will be different for each sound, and it is an important feature of the present invention to provide means, which may be of several different types, for utilizing the projected and screened beam to select and actuate an apropriate visual indicator.

Three alternative ways are described below for utilizing the energy of the electron beam passing through the screen to select and actuate an indicator. The first, for convenience, may be termed the "impulse system", the second, the "charge accumulative system", and the third, the 5 "direct fluorescent" or "direct illumination system".

In the first two systems, I position behind the screen a charge accumulating or conducting device, preferably, but not necessarily, in the form of a Faraday cage. In the third, I position behind the mask a fluorescent screen, preferably provided with visible indicia, such, for instance, as stenciled letters or word signs.

For each system, a slightly different form of target mask is used, although all three are basically the same. In the impulse system, each wave form or path is provided with a plurality of apertures which differ, from pattern to pattern as to their shape, spacing and/or number.

In the accumulative charge system the apertures along each sound trace differ as regards their number or size, whereas in the third (direct illumination) system, only one aperture is provided for each sound trace, and the apertures differ from one another only in the matter of their position.

In the first or impulse system, individual pulses are applied to the conductor positioned therebehind as the electron beam travels over the apertures in the mask arranged on a particular wave form pattern. These pulses are amplified, and may be used to actuate a high speed electrical integrator or indicator for actuating printS0 ing keys. Thus, each path traversed by the electron beam will create, in the circuit connected to the target, a series of unidirectional pulses which are different from series to series in the matter of their number, duration, or periodic frequency or a combination thereof.

Indicators adapted to be controlled and actuated by such pulsating currents are known in the art.

In the case of the cumulative charge system, the individual pulses Imparted by the electron beam to the charge accumulator behind the mask, as a result of the passage of the beam through the several openings on a particular path, are stored up until the end of the sweep of the beam for that particular sound. At the end of the sweep, a circuit is closed from the target to ground, and the potential of the discharge, which will be different for each sound track pattern, is utilized to control the selection of the appropriate indicator.

In the direct illumination system, the beam will pass through only one aperture during its traverse of a particular sound track. Positioned behind the mask is a fluorescent screen, adapted to be illuminated by the electron beam when it passes through the mask. Since the spot of illumination will be different for each sound trace, the mask acts as a selector. At the points on the screen, or on the end of the tube, correspending to the spots which will be illuminated by the beam, appropriate indicia, such as letters or other characters are positioned, so that they will be illuminated or indicated by the luminous spots on the fluorescent surface. Consequently, a letter or other character corresponding to the spoken sound will be Illuminated by the electron beam.

Thus, the spoken sound automatically controls the actuation of a particular indicating means, so that a visual indication corresponding to it is made.

As stated above, when either of the first two ways is used, there is positioned behind the mask a charge receiving device which may be in the nature of a Faraday cage. Such a device is particularly desirable in the charge accumulative system, because means must be provided to receive the successive charges projected through the screen. The same device may be used in the impulse system, or a simple plate of material of high electron absorption coeficient may be substituted. The mask should be insulated from the conducting or accumulating member, and this insulation is accomplished by spacing the members apart and, if desired, connecting the mask to ground. The apertures in the mask should have well defined, sharp edges.

If a Faraday cage type of collector is associated with the mask, its front face preferably is provided with openings registering with the pattern openings in the screen so that electrons projecting through the openings can enter the cage to be absorbed by the walls thereof, but so that the electrons will be restrained from being reflected outwardly thereof. In practicing my invention, it is essential that all of the sound waves traced on the target start from the same point and that all are released or set in operation by the voice itself. Each sound wave or trace will be different from the others, and the apertures are so located on the different traces as to take advantage of these differences most efficiently.

When the impulse system is used, the charge absorbing and conducting element behind the screen may be connected through appropriate amplification to a counter or indicator of the type used in teletype work or any other type of indicator, adapted to be actuated by the number, frequency and/or duration of the successive pulses may be used. The charge absorbing and conducting member behind the screen in the impulse system is so connected that the impulses are registered on the indicator circuit immediately as the electron beam traverses the pattern and projects through the openings thereon.

In the case of the charge accumulating method, the charges resulting from the projection of the beam through the several openings are stored up during the entire time that the beam travels across the mask, and means must be provided for discharging this accumulated charge at the end of the travel of the beam, so that the current may be utilized to effect the necessary selection of the proper indicating means. This means may comprise an auxiliary electrode positioned at the end of the several traces, adapted to close a circuit, by an appropriate relay, so that the accumulated current will flow from the collector to ground. By the interposition of an appropriate resistor in the last mentioned circuit, the potential drop across it will be applied to an appropriate amplification circuit to control the indicators. Alternatively, I may use a relay tube interposed in the O6 beam sweep circuit to close the circuit from the collector to ground when the current has risen sufficiently high in the sweep circuit to have moved the beam all the way across the target.

With my invention, either of two circuits, termed "sweep circuits" may be used to control the movement of the beam across the target. The first may be described as a voice released sweep circuit, which consists of a circuit adapted to cause the beam to make a single, relatively slow stroke across the target for each sound. The second Is a voice synchronized sweep circuit, which is recurrent, L e., similar to the so-called sawtooth relaxation oscillation impulses. In this type, the beam makes a great Splurality of strokes across the target during each sound. In the former, a constant period of time Is consumed by the beam during each traverse of the target. In the latter, the sweep velocity bears a definite sub-multiple relationship to the voice frequencies.

The voice stroke, signal released sweep circuit is preferable in certain cases, but it must be understood that my Invention is not limited thereto. A control electrode is located at the beginning position of rest to which the beam is normally directed when no voice current is in the sound circuit. When a current is impressed upon this circuit, by the admission of a sound, the beam will be deflected by the detector plates or coils in the cathode ray tube and will then be removed from the control electrode. Such removal of the beam will make a change in the current in a circuit connected to that electrode, which, through an appropriate thermionic relay, will start the operation of the sweep circuit to move the beam across the target. An electronic time delay may be inserted in this circuit, e. g., a current limiting tube, that is, one which draws a constant plate current may be used to decrease or control the sweep velocity If desired.

As is well known in the art, appropriate weak couplings between the impressed voice currents and the time base circuit may be used for "locking" or maintaining a relationship between the voice current and the rate of sweep or time of horizontal traverse.

In the foregoing general description, mention has been made of the use of a single electron beam tube in connection with this invention, but, for certain purposes, it is often desirable to use two or more such tubes connected in parallel. If it is desired to make the apparatus capable of indicating a great plurality of differing sounds, it is of advantage to use a plurality of electron tubes, each of which is provided with a screen having the openings thereof arranged on different patterns so that each tube controls a different group of visual indicators and is adapted to be actuated by a correspondingly different group of sounds. In such a case, the beam of electrons in each tube may move simultaneously along the same wave form, for each sound, but the mask in only one tube will have openings corresponding to each wave form, and that tube alone will be operative to control an indicator.

Alternatively, the tubes connected in parallel may be arranged in iuch a circuit that they operate in sequence so that one tube will operate at the beginning of a rather long sound, another tube at the middle portion thereof, and if desired, a third tube at the end of the sound. Each tube has associated with it a screen having a plurality of patterns corresponding to sound waves of the type that will be traced thereon as a result of the particular sounds which will control the beams. Thus, the apparatus in accordance with this conception will be capable of taking care of long and involved sounds.

Although the accumulative charge system described generally above has certain desirable features, is is Inherently limited in the number of wave forms that can be analyzed, by reason of the fact that the amount of the charge that can be stored up in the charge accumulator Is definitely limited by the nature and size thereof, and by the fact that the selection is based simply on magnitude of charge. With the impulse system, the charge absorbing and conducting member imposes no such limitation, because an almost infinite number of variations in the number, frequency, and duration of impulses can be worked out. As stated above, many electrical ci uits and systems for receiving and discriminating between electrical impulses are known in the art, and the system described below is flustrative only. Because of the shortness of the pulses and of the intervals between the pulses, it is preferable that the electric circuit be of a nature as to permit the functioning of the counter or indicator and/or to compensate for the time factor of the printing mechanism used. The circuit retains, delays or spreads out the pulses until such time as the printer is clear and releases them at a rate which mechanical keys can follow. I prefer to use a gas vapor electron tube, of the thyratron type. It is essential to prevent the interpreting Impulses from outstripping or getting ahead of the time limitations of the particular high speed counter or printing mechanism adapted to be controlled thereby.

In the accompanying drawings, I have shown diagramatically a number of different methods and means for accomplishing the objects of this invention. It must be understood that the drawings are illustrative only, and are not restrictive of the invention.

In the drawings:Figure 1 is a diagrammatic view of one form of the invention; so Figure 2 is a diagrammatic view of a modification; Figure 3 is an enlarged detail at one end of the cathode ray tube of Figure 2; Figure 4 is an end elevation of the device of Figure 3; Figure 5 is an enlarged detail of a cathode lay tube which may be used in connection with the method and apparatus of Figure 1; Figure 6 is a circuit diagram of one form of the invention; Figure 7 is a modified circuit which may be used with the circuit of Figure 6; Figure 8 is a diagrammatic elevational view of an apertured mask which may be used with the cathode ray tube; Figure 9 is a circuit diagram of a modification, in which two cathode ray tubes are connected in parallel; and Figure 10 is a diagrammatic view of a novel printing mechanism.

Figure 1 shows one plan of arrangement of the various elements of the invention. A telephone transmitter or microphone I is connected to suitable amplfication 2, and thence to a filter 5 or series of filters 3. A sweep circuit 4 is interposed between the filter and the electron bear tube 5. The cathode ray device may be provided with a metallic envelope, and includes horizontal plates 8 and vertical plates 7 which cause deflection of the cathode ray beam in two directions. Thus, the beam will trace a wave form path across an apertured mask 8. Positioned behind the mask is a collector or conductor 9, which, for instance,. may be a Faraday cage. this Is connected, through appropriate amplification 10, to an indicator or printer II.

In the circuit from the filter 3 to the horizontal plates 6, I may provide, If desired, an amplitude control device 12 for the currents in that circuit.

In the system of Figure 2, instead of using a charge collector with the cathode ray tube, I provide a fluorescent screen 13 and a plurality of visual indicators 14, adapted to be illuminated to make a proper indication. As shown in Figure 3, the anner surface of the end face of the tube may be provided with a coating of fluorescent material II. such as calcium or strontium tungst.ae, zino sulphate or the like. Ordinarily, such materials are poor conductors, and in order to increase the excited time life of the material, It is desirable to compound therewith a good conductor to spread the fluorescence. Moreover, it is desirable to add a trace of lead to increase the sensitivity of the coating.

On the surface of the end face of the tube I provide a plurality of visual indicia 14, which may be in the form of dark figures on a translucent ground or stenciled openings in a relatively opaque coat. These figures may be illuminated directly by the fluorescent material positioned therebehind, or, small spots may be illuminated immediately above or below each indicia. The screen I associated with the tube of Figures 2 and 3 is provided with a plurality of apertures II, II', etc., each being adapted to illuminate a different indicia when the electron beam projects therethrough. The apertures are posltioned so that one aperture only lies on each wave form path adapted to be traversed by the beam. Thus, only one indicia will be illuminated by each sound.

Referring to Figures 5 and 8, a screen adapted to be used with the system of Figure 1 is disclosed. This screen has a plurality of openings 16, 16', etc., II, II', spaced along the paths IW, 18', etc., adapted to be traversed by the electron beam as controlled by different sounds. As 3a stated above, the number, size, shape or spacing of the openings along the paths are different.

Consequently, the collector II, which may be in the form of a Faraday cage Is, will be subjected to different amounts, numbers, or frequencies of electron charges for each wave form path traversed by the beam. These charges or Impulses are conducted from the collector by an appropriate circuit through appropriate amplification to the indicator or printer II.

Referring to Figure 6, the microphone or telephone transmitter I is shown as connected to a conventional resistance capacitance coupled twostage amplifier 23. A three-stage filter chain 24 is shown connected to the output of the ampli0 fier but, of course, it must be understood that the filter chain could precede the amplification.

The number of filter units or elements shown in the chain is arbitrary, as any suitable or desired number may be used. Although a particular class of filter is shown, it should be understood that high pass, low pass or band pass filters may be substituted.

In circuit with the filters and the cathode ray tube, there is a sweep circuit 4, which, as shown (o in Figure 6, is of the signal synchronized, recurrent stroke type. This circuit applies electrical charges to the vertically disposed plates to impart horizontal movement -to the beam, to cause the beam to sweep longitudinally of the screen. The voice current is also applied to the other pair of plates I to control the movement of the beam in the opposite direction.

As indicated at 25 in Figure 6, a circuit Is provided in which the Impulses from the Faraday cage II are applied, sucessively to the gridi of a plurality of vapor discharge electron tube An amplifier or any means or device for accelerating the electron motion may be used betweer the cage and th'r first tube in the circuit 21. Th< 78 tubes of this circuit are arranged in a mannei known as a ring circuit, and Impulses imparted thereto are stored up in the tubes successively and are removed therefrom successively by the final tube 2t, which also restores each tube successively to its former condition. These Impulses, as discharged from the tube 26, serve to actuate a printing mechanism of any desired type such, for Instance, as shown in Figure 10.

Any equivalent circuit, adapted to perform the general function of retaining the impulses, or of accommodating the inherent time delay of mechanical printing mechanism is suitable.

In the circuit of Figure 6, and interposed between the voice circuit and the printing magnet 2I, there is an appropriate electronic time delay $0. This device is adjustable so that a printing impulse will be applied to the printing magnet 28 through conductors 21 following a predetermined time after the initiation of current In the voice circuit. Thus, the circuit 25 is a time delay to permit the individual impulses to be recorded on the printing device, so that the inherent time factor of the mechanical printing device will be compensated for and each impulse will have its proper effect on the counter. The time circuit I3 controls the printing impulse, and delays that Impulse sufciently to permit the printer to have been moved to the proper position before printing. If simple words are used, this control is superfluous. o0 Instead of using a separate circuit for controlling the printing impulse, that impulse may be transmitted over the same circuit as the indicator selecting impulses by the use of a voice synchronized motor, clutch driven series of cams 5 to distribute or direct the selection of a final path to the printing key of a particular sound.

In Figure 7, an alternative sweep circuit 35 is shown. Such a circuit is a single stroke, signal released circuit In connection with this type of circuit, one may use a control electrode 11 (Figure 8), asociated with the mask I. When the electron beam is caused to move off of the control electrode 21 at the position of rest by a current flowing in the voice circuit, the tube 36 (Figure 7) will permit the flow of current through the sweep circuit, and as this current gradually increases, the beam moves, relatively slowly, across the target. When a predetermined potential has been thus created in the sweep circuit, the beam will 60 have traveled all the way across the screen, and the relay 13 will close. Thereupon, a printing Impulse of current will flow through the wires 38 to the printing solenoid 21 associated with the indicator. The voice current flows into this cir- Sa cult through wires I$, connected to the horizontally disposed plates I of the cathode ray tube.

Instead of using the relay 13 to initiate printing impulse at the end of the traverse of the beam across the target, an auxiliary control electrode 2T' (Figure 8) may be provided, and in such a case, that electrode should be connected through an appropriate time delay circuit, such as that shown at 30 in Figure 6 to the printing solenoid.

Figure 9 discloses a preferred manner in which two .or more cathode ray tubes 5 and I' may be connected in parallel. In this diagrammatic illustration, the signal input is represented at 40 and the sweep input at 41. The sweep circuits TO 42, 41, associated with each tube may be adjusted to work simultaneously,- or to operate differenStially so as to make a different wave form for Sthe same sound. Alternatively, one circuit may r operate subsequently to the other, by the inter- Ty position of a switch in the circuit actuated by an appropriate electronic time delay device.

The form of printing mechanism, disclosed diagrammatically in Figure 10 has certain features for use with my inrentlon. A printing drum 45 is loosely mounted on a shaft 46, and is provided with a coll spring 41 connected at one of its ends to the hub 41 and at its other end to a stationary part, such as a buffer 49. An annular ratchet 50 is attached to the drum, so that movement may be imparted thereto by the springpressed pawl I1 pivoted to the actuating lever 52.

A series of printing keys 53 are mounted around the periphery of the drum. Below the drum appropriate means are provided for supporting and actuating, step by step, a printing ribbon 64 and a strip of paper 55 or the equivalent thereof. A 4 vertically movable, two-position printing platen 5B is disposed beneath the paper. A cam or lug 51 associated with the drum 46 Is positioned to close contacts 58 when the drum is at rest and is in the start position, as determined by the buffer 43 and cooperating stop lug 85. In circuit with the contacts 68 is a solenoid 60, which will raise the printing platen 56 when energized. The platen has an inclined surface or wedge 6 which will control the position of the normally open springpressed contacts $2, In circuit with a magnet or solenoid 63, which is adapted to shift the posltlon of lever 64 to disengage pawl I1 and locking detent 65 to permit the spring 47 to return the drum to start position. Impulses from the circuit 25 or the equivalent are applied to the counter-mechanism by conductors 1), and through an s3 appropriate relay II and battery 12, actuate the counting magnet 17. For each impulse thus Imparted, to magnet 17, the lever t2 will move one stroke, and the drum, through the pawl and ratchet mechanism 50, 51, 65 will be moved. The printing impulses, either from conductors 38 of the circuit of Figure 7, or from the conductors 29, Figure 6, are applied to the printing solenoid or relay 28 to actuate the lever 15 which depresses the appropriate printing key 53, to print an indicia corresponding to the sound emitted. Depression of the printing key 53 results in a downward movement of the wedge 61 and a closing of the contacts 62. Thereupon, the. magnet 68 is energized and the lever 64 shifted to position to 50o disengage the pawl I1 and detent 68, to permit the drum to return to its original position. Such action closes the contacts 58 and energizes the solenoid 60, whereupon the platen is shifted to its upper position for a subsequent printing opsB eration, and the lever 64 is shifted to permit the detent and pawl 81 again to engage the ratchet.

Thus, the parts are in position for the next printing operation.

It must be understood that any well known type co of impulse printer may be substituted for the novel one disclosed herein.

If it is desired to use an instantaneous volume control In connection with this.invention, a control of the type shown in United States Patent No. 1,737,830 is suitable.

I claim:1. The method of producing visible intelligible indicia corresponding to intelligible audible sounds, comprising propagating such a sound, projecting a movable beam, causing said beam to traverse a wave form path, controlling the form of said path by said sound, providing a plurality of indicators, each adapted to indicate a visible indicia corresponding to an intelligible audible sound, selecting, by means controlled by said wave form path, the indicator corresponding to the sound utilized to control the form thereof, and actuating said Indicator to make said indicia visible.

2. The method of producing a visible intelligible indicia corresponding to intelligible sounds, comprising propagating Auch a sound, projecting a moving beam onto a target, causing said beam to traverse a wave form path on said target corresponding to said sound, providing a plurality of visible intelligible indicators, selecting an indicator corresponding to said sound by selection effected by said wave form path on said target traversed by said beam, and actuating said indicator. 3. The method of producing visible intelligible indicia corresponding to intelligible audible sounds, comprising providing a target having a plurality of active areas thereon, said areas being arranged in accordance with a plurality of wave form patterns corresponding to predetermined audible sounds, propagating a sound, projecting a beam and causing the same to traverse a wave form path on said target, controlling the form of said path by said sound to g2 substantially coincide with one of said patterns on said target, and actuating an indicator corresponding to said sound by energy transmitted through the active areas of said pattern.

4. The method of producing visible intelligible Indicia corresponding to intelligible audible sounds, comprising providing a target having a plurality of isolated electron transmissive spots thereon arranged in accordance with a plurality of patterns, propagating an audible sound, projecting a beam of electrons onto said target, causing the same to traverse a wave form path, controlling the form of said path by said sound, and causing the same to substantially coincide with one of said patterns, and using the beam of electrons encountering said transmissive spots on said target to select an indicator corresponding to said sound.

5. The method of producing visible intelligible indicia corresponding to predetermined sounds, 4 comprising propagating such a sound, projecting an electron beam, causing the beam to traverse a wave form path corresponding to said sound, masking said beam during a portion of said path, and utilizing the beam during the unmasked portion of the path to control the selection and actuation of a visual indicator corresponding to said sound.

6. The method of producing visible intelligible indicia corresponding to predetermined sounds, M comprising propagating such a sound, projecting an electron beam, causing the beam to traverse a wave form path corresponding to said sound, masking said beam during a portion of its traverse of said path and unmasking it during another portion, providing visual indicators for a plurality of predetermined sounr's, and selecting the proper indicator corresponding to said propagated sound by the beam during the unmasked portion of its traverse of said path. 6 7. The method of producing visible intelligible indicLa corresponding to predetermined sounds, comprising propagating such a sound, projecting an electron beam, causing the beam. to traverse a wave form path corresponding to said sound, masking said beam during a portion of its traverse of said path and unmasking it during other interrupted portions and thereby causing an intermittent projection of said beam beyond the mask, and utilizing the sum of the projections of said beam during the unmasked portions to control the selection of an indicator corresponding to said sound.

8. The method of producing visible intelligible indicia corresponding to predetermined sounds, comprising propagating such a sound, projecting an electron beam, causing the beam to traverse a wave form path corresponding to said sound. maskin said beam during a portion of its traverse of said path and unmasking it during other interrupted portions and thereby causing an intermittent projection of said beam beyond the mask, and utilizing the number or duration or frequency of the projections of the beam during the unmasked portions of the path to control the selection of an indicator corresponding to said sound.

9. The method of producing visible intelligible' indicia corresponding to predetermined sounds, comprising propagating such a sound, projecting an electron beam, causing the beam to traverse a wave form path corresponding to said sound, masking said beam during the major portion of its traverse of said path and unmasking it at a single definite point in its path and thereby causing a single Isolated projection of said bham beyond the mask during its traverse of said path, and utilizing said projection of said beam to control the selection of an indicator corresponding to said sound.

10. The method of producing visible intelligible indicia corresponding to predetermined sounds, comprising propagating such a sound, projecting an electron beam, causing the beam to traverse 3 a wave form path corresponding to said sound, masking said beam during the major portion of its traverse of said path and unmaskin It at a single definite point in its path and thereby causing a single isolated projection of said beam beyond the mask during its traverse of said path, and utilizing said projection of said beam to illuminate a fluorescent area to make visible an Indicia corresponding to said sound.

11. An apparatus for converting intelligible Ssounds into visible Intelligible indicia comprising means for producing an undulating current corresponding to a particular ound, means for projecting a focussed beam of electrons, means for causing said beam to traverse a wave form path corresponding to said undulating current, a plurality of visual indicators corresponding to a plurality of said sounds, and selector means controlled by the beam in its traverse of stid wave form path to control the actuation of one of said indicators corresponding to the sound producing said undulating current.

12. Electron control apparatus comprising, in combination, means for projecting a beam of electrons, means for causing said beam to traverse a wave form path and for controlling the contour of said path, an electron absorber positioned to be encountered by said beam, and a mask interposed between said source and said electron absorber, said mask being imperforate throughout the major portion of its area and having a plurality of holes therethrough, said holes being arranged to coincide with a path or predetermined contour traversed by said beam of electrons under the control of said means, thereby to effect projection of said beam through the holes in said mask and the contact thereof upon said absorber.

13. Means for converting speech sounds into visible indicia comprising means for projecting a beam of electrons, means for causing the beam to traverse a different path for each sound, a screen in the fleld of said beam of electrons, said screen having a plurality of patterns of perfarations So thereon, each pattern coinciding with a particular path, a plurality of indicators and means actuated by the projection of said electron beam through said screen to select an indicator corresponding to the pattern traversed by said beam M and to the corresponding sound.

14. An apparatus for converting sounds into visible indicia comprising a microphone, means for filtering and amplifying voice currents controlled by said microphone, a cathode ray tube, 4 circuits for controlling the projection of the electron beam therein as to amplitude and time, a perforated screen associated with said tube, a charge selector positioned behind the screen, and a printing device adapted to be controlled by said charge selector.

WALLACE WATT J. FULLER.

CERTIPICAV OF CORIMOTION.

rtlent.No.. 2,137,88.

November 22, 1938.

It is hereby certified that the name of the patentee in the above nambered patent was erroneously written and printed as "Wallace Watt J. Puller" whereas said name should have been written and printed as Wallace W.

Fuller, as shown by the reoords of this office and that the said Letters Patent should be read with this correotion therein that the same zay conform to the record of the case in the Pateht Offioe.

Signed and sealed this 14th day of February, A.D. 1939.

Henry Van Arsdale.

Acting Coomissioner of Patents.

(seal)