DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] Preferred embodiments of the present invention will be described below, referring to the attached drawings.

[0046] The First Embodiment

[0047] In the first embodiment, an information signal recording device 10 , which is referred to as a recording device hereinafter, shown in FIG. 1 is a device for receiving digital information signals provided through a network such as Internet and then recording them on a recording medium.

[0048] An information signal reproducing device 20 , which is referred to as a reproducing device hereinafter, shown in FIG. 6 is a device for reproducing information signals recorded on the recording medium and, for example, displaying reproduced images on a display or transmitting them to other communication devices through a network such as Internet.

[0049] In short, the recording device 10 and the reproducing device 20 are devices such as a personal computer which can transmit and receive information signals through a network such as Internet, and the recording device 10 corresponds to a recording system in a device such as a personal computer, and the reproducing device 20 corresponds to a reproducing system in the same device.

[0050] When information signals are recorded on a recording medium, information intrinsic to the individual medium (medium intrinsic information) is added, as information related to the recording medium on which the information signals are to be recorded, to the information signals and then the resultant information signals are recorded on the recording medium, which will be in detail described later. In the case wherein the information signals recorded on the recording medium attempt to be reproduced, the signals are reproduced only when the aforementioned medium intrinsic information added to the information signals to be reproduced is consistent with the medium intrinsic information which the recording medium on which the information signals to be reproduced are recorded has.

[0051] In other words, when an individual user uses the recording device 10 which will be explained below so as to copy the information signals in an ordinarymanner for private use, the medium intrinsic information added to the copied information signals will be made consistent with the medium intrinsic information which the recording medium on which the information signals are recorded has.

[0052] In the case wherein for every recording medium on which the information signals are to be recorded the medium intrinsic information of the medium is not added to the information signals to be recorded, but in the case wherein the same information signals are copied on many recording media, for example, by copying the information signals recorded on a single recording medium onto other recording media, the medium intrinsic information which is added to the information signals and which will be consistent in the case of copying in an ordinary manner is not consistent with the medium intrinsic information which the recording medium on which the information signals are recorded has. In this case, therefore, reproduction is prohibited, and illegally copying of the information signals in a manner different from the ordinary manner is prohibited.

[0053] Recording Device 10

[0054] The recording device 10 in the first embodiment will be firstly described.

[0055] FIG. 1 is a block diagram for explaining the recording device 10 in the first embodiment. As shown in FIG. 1 , the recording device 10 has an input terminal 11 for inputting information signals, a copy preventing control information-detecting section 12 , a timing generator 13 , an SS additional information generator 14 (The SS is an abbreviation of spread spectrum, which is the same hereinafter.), an SS additional information superimposing section 15 , a writing section 16 , a medium intrinsic information reading section 17 , and a system controller 200 for controlling the respective sections in the recording device 10 .

[0056] A recording medium 100 is a medium on which various digital information signals such as digital image signals, digital sound signals and programs are recorded by this recording device 10 , including discs such as a CD-ROM and a DVD. In the following, for simplifying explanation information signals which are supplied to the recording device 10 through the input terminal 11 for inputting information signals and are recorded on the disc 100 are digital image signals.

[0057] The digital image signals S 1 supplied to the recording device 10 are signals to which copy preventing control information called CGMS (copy generation management system) is inserted and added. The copy preventing control information called the CGMS is, for example, 2-bit information representing the content of copy control for the digital image signals S 1 , such as allowance of copying, prohibition of copying, or copying generation restriction.

[0058] When the disc 100 for recording information signals is set into the recording device 10 and a user gives an instruction for starting record of image signals through an operation key section 201 connected to the system controller 200 , the controller 200 controls the respective sections in the recording device 100 so as to start the recording process for recording the supplied information signals onto the disc 10 .

[0059] Digital image signals S 1 transmitted from a network such as Internet and received by the recording device 10 are supplied to the copy preventing control information detecting section 12 , the timing generator 13 and the SS additional information superimposing section 15 in the recording device 100 .

[0060] The copy preventing control information detecting section 12 detects the copy preventing control information according to the CGMS which is added to the supplied digital image signals S 1 , and then communicates the detected copy preventing control information to the system controller 200 .

[0061] When the information from the copy preventing control information detecting section 12 shows that any copying is prohibited, the system controller 200 controls the respective sections not to record the digital image signals S 1 . When the information from the copy preventing control information detecting section 12 shows that copying is allowable, the system controller 200 controls the respective sections in the device 10 to record the digital image signals S 1 on the recording medium 100 .

[0062] When the digital image signals S 1 can be copied, the medium intrinsic information reading section 17 reads a serial number intrinsic to every disc recorded in, for example, a TOC (Table Of Contents) of the disc 100 , and supplies this as medium intrinsic information B 1 to the SS additional information generator 14 .

[0063] The reference timing generator 13 detects reference timing signals from the supplied digital image signals S 1 and then generates timing signals TM and clock signals CLK used in the respective sections in the recording device 100 on the basis of the detected reference timing signals.

[0064] FIG. 2 is a block diagram for explaining the timing generator 13 in the recording device 10 . As shown in FIG. 2 , the timing generator 13 has a reference timing detecting section 131 , a PLL circuit 132 and a timing signal generator 133 .

[0065] The timing detecting section 131 extracts synchronous signals DK as the reference timing signals from the digital image signals S 1 supplied to the section 131 , and then supplies the signals to the PLL circuit 132 and the timing signal generator 133 .

[0066] The PLL circuit 132 generates clock signals CLK synchronized with the digital image signals S 1 on the basis of the synchronous signals DK from the reference timing detecting section 131 . The clock signals CLK are supplied not only to the timing signal generator 133 but also to the respective sections using the clock signals CLK such as the SS additional information generator 14 which will be in detail described later.

[0067] The timing signal generator 133 generates timing signals TM for use in the SS additional information generator 14 and other various timing signals on the basis of the synchronous signals DK from the reference timing detecting section 131 and the clock signals CLK from the PLL circuit 131 .

[0068] The timing signals TM generated in the timing signal generator 133 are synchronized with the synchronous DS from the reference timing detecting section 131 , and are used as reset (initializing) signals for taking timing for generating a PN code series having a predetermined code pattern used for spectrum-spreading from the head of the code series, in the SS additional information generator 14 .

[0069] When, for example, vertical synchronizing signals are extracted as reference timing signals in the reference timing detecting section 131 in the timing generator 13 , the clock signals CLK synchronized with the vertical synchronizing signals from the reference timing detecting section 131 are generated in the PLL circuit 132 .

[0070] In the timing signal generator 133 , on the basis of the vertical synchronizing signals from the reference timing detecting section 131 and the clock signals CLK from the PLL circuit 132 , timing signals TM synchronized with the vertical synchronizing signals used as reference timing signals are generated, so as to make one field correspond to one cycle.

[0071] As shown in FIG. 1 , the timing signals TM and the clock signals CLK thus generated in the timing generator 13 are supplied to the SS additional information generator 14 .

[0072] The SS additional information generator 14 receives the supply of the medium intrinsic information B 1 , the timing signals TM and the clock signals CLK and then generates SS medium intrinsic information (SS additional information) SB 1 , which is a spread spectrum signal of the medium intrinsic information B 1 .

[0073] FIG. 3 is a block diagram for explaining the SS additional information generator 14 . As shown in FIG. 3 , the SS additional information generator 14 comprises a PN (Pseudorandam Noise) code generator 141 and a multiplier 142 .

[0074] The PN code generator 141 generates a PN code series PS, on the basis of the timing signals TM and the clock signal as CLK. Specifically, at every timing that the timing signal TM is supplied, the PN code generator 141 generates the PN code series PS from its head, in synchronization with the clock signals CLK, and then supplies this to the multifier 142 .

[0075] Into the multifier 142 , supplied are medium intrinsic information rows B 1 R which are generated by outputting medium intrinsic information B 1 from the medium intrinsic information reading section 12 in such a manner that bits corresponding to the predetermined number of clocks are outputted in synchronization with the clock signals CLK at every timing given by the timing signal TM.

[0076] In the multifier 142 , the PN code series PS are multiplied by the medium intrinsic information rows B 1 R, so as to generate spread spectrum signals (SS medium intrinsic information), which are spectrum-spread medium intrinsic information.

[0077] As described above, the SS additional information generator 14 has a function as a spreading means for making medium intrinsic information B 1 having a narrow band and a high level into SS medium intrinsic information SB 1 having a wide and a low lever by using the PN code series PS to spectrum-spread the medium intrinsic information B 1 . This will be in detail described later.

[0078] FIG. 4 is a view illustrating a structural example of the PN code generator 141 shown in FIG. 3 . The PN code generator 141 of this example comprises D flip-flop circuits REG 1 -REG 12 constituting 12 steps of sift resistors, and Exclusive-OR circuits EX-OR 1 -EX-OR 3 for calculating appropriate tap outputs from the sift resistors. The PN code generator 141 shown in FIG. 4 generates PN code series PS in the M (Maximum) length sequence on the basis of the timing signals TM and the clock signals CLK, as described above.

[0079] Enable signals EN in FIG. 4 are signals for falling the PN cord generator 141 into an operating state. In the first embodiment, the enable signals are generated, for example, by switching on the recording device 10 shown in FIG. 1 , and then supplied to the PN cord generator 141 .

[0080] The SS medium intrinsic information SB 1 thus obtained from the SS additional information generator 14 is supplied to the SS additional information superimposing section 15 .

[0081] The signal superimposing section 15 receives the supply of the digital image signals S 1 and the digital SS medium intrinsic information SB 1 , and then generates digital image signals S 2 on which the SS medium intrinsic information SB 1 as a digital signal is superimposed.

[0082] When the digital image signals S 1 are composed of, for example, a 10 bit-source, in which an image of 1 pixel is represented by 10-bit signals, the SS medium intrinsic information SB 1 is superimposed on the least significant bit (LSD) in the 10-bit digital image signals, or the ninth bit adjacent to the LSD in the SS additional information superimposing section 15 . In this manner, the SS additional information superimposing section 15 causes the SS medium intrinsic information SB 1 to be superimposed on the digital image signal S 1 within the same time and the same frequency.

[0083] In this case, the SS additional information superimposing section 15 causes the SS medium intrinsic information SB 1 to be superimposed on the digital image signals S 1 at a lower signal electric power than the dynamic range of the digital image signals S 1 , so that the digital image signals S 1 will not be deteriorated by the SS medium intrinsic information SB 1 . The digital image signals S 2 thus formed by superimposing the SS medium intrinsic information SB 1 on the digital image signals S 1 in the SS additional information superimposing section 15 are supplied to the writing section 16 .

[0084] The writing section 16 receives the supply of the digital image signals S 2 on which the digital SS medium intrinsic information SB 1 is superimposed, converts this into digital image signals suitable for writing, and then permits the digital image signals for writing to be recorded on the recording medium 100 .

[0085] As will be in detail described below, the SS medium intrinsic information SB 1 superimposed on the digital image signals recorded on the recording medium 100 is spectrum-spread, and consequently reproduction images based on the digital image signals are not deteriorated, and not altered nor erased.

[0086] FIGS. 5A to 5 D are diagrams of spectrums showing the relationship between information signals, in particular image signals in the present example, and additional information, such as medium intrinsic information, added to the information signals. The additional information includes a small deal of information, and is low-bit information and narrow band-information as shown in FIG. 5A . This is subjected to spectrum-spreading, resulting in wide band-information as shown in FIG. 5B . At this time, the spectrum-spread signal level becomes lower in inverse proportion to the expansion rate of the band.

[0087] These spread spectrum signals, that is, pieces of the SS medium intrinsic information SB 1 , are superimposed on the information signals on the SS additional information superimposing section 15 . In this case, as shown in FIG. 5 C, the SS medium intrinsic information SB 1 is superimposed at a level lower than the dynamic range of the image signals as the information signals. By such superimposing, the information signals are hardly deteriorated. Thus, when the image signals on which the SS medium intrinsic information SB 1 is superimposed are supplied to a monitoring device, good images are reproduced without substantial influence of the SS medium intrinsic information SB 1 .

[0088] However, when inverse spectrum-spreading is performed in such a manner as will be in detail described later so as to detect the SS medium intrinsic information SB 1 as additional information at a recording side, the SS medium intrinsic information SB 1 is again restored to a narrow band signal (additional information) as shown in FIG. 5D . By giving a sufficient band spreading rate, the electric power of the copy control information after being inverse-spread-spread becomes more than that of the information signals, so that the SB 1 can be detected.

[0089] In this case, the SS medium intrinsic information SB 1 superimposed on the image signals cannot be erased nor altered by any frequency filter or simple replacement of information, since the information SB 1 is superimposed within the same time and frequency as those of the image signals.

[0090] As described above, the SS medium intrinsic information SB 1 superimposed on the digital image signals is spectrum-spread and superimposed as wide band and low level signals, and consequently the information SB 1 does not cause image signals reproduced from the digital image signals to be deteriorated.

[0091] Since the SS medium intrinsic information SB 1 is superimposed on the digital image signals within the same time and frequency, the newly additional image signals cannot be erased nor altered by any frequency filter or replacement of information signals.

[0092] As described above, the spectrum-spread medium intrinsic information is superimposed on the digital image signals within the same time and frequency; therefore, even if the digital image signals on which the spectrum-spread additional information is superimposed are D/A-converted into analog signals, they are never erased.

[0093] When the supplied digital signals are recorded on the disc in the recording device 10 , a serial number which is recorded on the TOC and which is information intrinsic for every disc is spectrum-spread as medium intrinsic information and then this is superimposed on the digital image signals S 1 to be recorded, as described above. The digital image signals S 2 on which the spectrum-spread medium intrinsic information is superimposed are recorded on the disc 100 .

[0094] In short, the recording device 10 in the present embodiment makes it possible to spectrum-spread the medium intrinsic information, superimpose it on the digital image signals to be recorded on the disc 100 , and then record it on the recording medium, without the digital image signals recorded on the disc 100 being deteriorated nor the medium intrinsic information superimposed on the digital image signals being altered.

[0095] When this recording device 10 is used to record the information signals in an ordinary manner, the spectrum-spread medium intrinsic information for superimposition on the image signals is made consistent with the medium intrinsic information of the recording medium on which the image signals are to be recorded.

[0096] Reproducing Device 20

[0097] The following will describe the reproducing device 20 .

[0098] FIG. 6 is a block diagram for explaining the reproducing device 20 . As shown in FIG. 6 , the reproducing device 20 has a reading section 21 , a medium intrinsic information reading section 22 , an SS additional information detecting section 23 , a timing generator 24 , a reproduction allowance/prohibition determining section 25 , a reproduction processing section 26 , an indicative information generator 27 , an LCD(Liquid Crystal Display) driver 28 , an LCD 29 , an information signal erasing section 31 , and a system controller for controlling the respective sections in the producing device 20 .

[0099] The reproducing device 20 is a device for reproducing and outputting the digital image signals recorded on the disc 100 by the aforementioned recording device 10 . Namely, the reproducing device 20 is a device for reproducing the digital image signals on which the spectrum-spread medium intrinsic information is superimposed.

[0100] When an instruction is given for starting reproducing the image signals recorded on the disc 100 set by a user through an operation they section 201 connected to the system controller 200 in the reproducing device 20 , the system controller 200 controls the respective sections in the reproducing device 20 so as to start reproducing process.

[0101] The reading section 21 in the reproducing device 20 generates digital regenerative image signals S 12 from signals S 11 obtained by reproducing the information signals recorded on the disc 100 , and then supplies them to the SS additional information detecting section 23 , the timing generator 24 and the reproduction processing section 26 .

[0102] The timing generator 24 has the same structure as the aforementioned timing generator 13 , referring to FIG. 2 , and generates timing signals TM and clock signals CLK for use in the respective sections in the reproducing device 20 . Therefore, the timing generator 24 will be described, as the structure shown in FIG. 2 .

[0103] The reference timing detecting section 131 in the timing generator 24 extracts synchronous signals DK as reference timing signals from the digital image signals S 12 supplied to the section 131 . The synchronous signals DK are supplied to the PLL circuit 132 and the timing signal generator 133 .

[0104] The PLL circuit 132 generates clock signals CLK synchronized with the digital image signals S 12 , on the basis of the synchronous signals DK from the reference timing detecting section 131 , and supplies them to the respective sections, for example, the timing signal generator 133 and the SS additional information detecting section 23 which will be in detail described later.

[0105] The timing signal generator 133 generates and outputs timing signals TM and other various timing signals for use in the respective sections, for example, the SS additional information reading section 22 and the SS additional information generator 25 , on the basis of the synchronous signals DK from the reference timing detecting section 131 and the clock signals CLK from the PLL circuit 132 .

[0106] In the reproducing device 20 , the timing signals TM and the clock signals CLK give the same timing as the timing signals TM and the clock signals CLK used in the aforementioned recording device 10 .

[0107] As shown in FIG. 6 , the timing signals TM and the clock signals CLK thus generated in the timing generator 24 are supplied to the SS additional information detecting section 23 .

[0108] The SS additional information detecting section 23 carries out inverse spectrum-spreading to extract the medium intrinsic information B 1 which is spectrum-spread and superimposed on the digital regenerative image signals S 12 , and then supplies this to the reproduction allowance/prohibition determining section 25 .

[0109] Specifically, the SS additional information detecting section 23 has a PN code generator and a multiplier not illustrated, and generates a PN code series for inverse-spreading having the same code patter as the PN code series for spectrum-spreading the medium intrinsic information B 1 which is spectrum-spread and superimposed on the digital image signals S 12 , with their generating timing being consistent, on the basis of the timing signals TM and the clock signals CLK from the aforementioned timing generator 24 . The section 23 carries out the inverse spectrum-spreading by using the PN code series for inverse-spreading so that the medium intrinsic information B 1 superimposed on the digital regenerative signal component S 12 will be extracted from the signal component S 12 .

[0110] On the contrary, the medium intrinsic information reading section 22 reads the serial number of the disc 100 recorded in the TOC of the disc 100 as medium intrinsic information, in the same manner as the medium intrinsic information reading section 17 in the recording device 10 , and then supplies this to the reproduction allowance/prohibition determining section 25 as the medium intrinsic information B 2 of the recording medium on which the digital image signals to be reproduced are recorded.

[0111] The reproduction allowance/prohibition determining section 25 determines whether or not the medium intrinsic information B 1 superimposed on the digital image signals which are read from the disc 100 and supplied from the SS additional information detecting section 23 is consistent with the medium intrinsic information B 2 of the disc 100 which is read by the medium intrinsic information reading section 22 , and then generates a control signal CT 1 or CT 2 according to the determination to supply it to the reproduction processing section 25 and the indicative information generator 27 .

[0112] In other words, when the medium intrinsic information B 1 from the SS additional information detecting section 23 is consistent with the medium intrinsic information B 2 from the medium intrinsic information reading section 22 , the reproduction allowance/prohibition determining section 25 concludes that the image signals recorded on the disc 100 are signals properly copied in an ordinary manner, and then generates the control signal CT 1 for allowance of reproduction so as to supply this to the reproduction processing section 26 .

[0113] When the control signal CT 1 from the reproduction allowance/prohibition determining section 25 is a signal for allowance of reproduction, the reproduction processing section 26 performs a process for encoding the digital image signals and the like processes to generate and output regenerative image signals.

[0114] When the reproduction allowance/prohibition determining section 25 determines that the medium intrinsic information B 1 from the SS additional information detecting section 23 is not consistent with the medium intrinsic information B 2 from the medium intrinsic information reading section 22 , the reproduction allowance/prohibition determining section 25 concludes that the image signals recorded on the disc 100 are not signals properly copied, and then generates the control signal CT 1 for prohibiting reproduction and supplies this to reproduction processing section 26 . At the same time, the section 25 generates a control signal CT 2 for displaying the fact that the digital signals recorded on the recording medium 100 cannot be reproduced on the LCD 29 and then supplies this to the indicative information generator 27 .

[0115] In this case, the reproduction processing section 26 does not permit the digital image signals S 12 to be reproduced. The indicative information generator 27 receiving the supply of the control CT 2 generates message information that the image signals recorded on the recording medium 100 may not be signals copied in an ordinary manner and they cannot be reproduced, so as to display this on the LCD 29 through the LCD driver 28 .

[0116] Furthermore, in this case, the reproduction allowance/prohibition determining section 25 informs the system controller 200 that the medium intrinsic information B 1 from the SS additional information detecting section 23 is not consistent with the medium intrinsic information B 2 from the medium intrinsic information reading section 22 . After receiving this information, the system controller 200 controls the information signal erasing section 31 to erase the information signals recorded on the recording medium 100 .

[0117] The information erasing section 31 makes it impossible to read the image signals on which the medium intrinsic information different from the medium intrinsic information of the disc 100 is superimposed. That is, this section 31 is a section for carrying out a so-called logically erasing.

[0118] Of course, it is possible to initialize the disc 100 so as to erase the whole of the information signals recorded on the disc 100 , or to physically erase the image signals on which the medium intrinsic information different from the medium intrinsic information of the disc 100 is superimposed.

[0119] Action of the recording device 10 and the reproducing device 20 :

[0120] The following will describe the flow of action of the aforementioned recording device 10 and the reproducing device 20 , referring to flowcharts shown in FIGS. 7 and 8 .

[0121] FIG. 7 is a flowchart for explaining the flow of the action of the recording device 10 . The process shown in FIG. 7 is started when, for example, a user of the recording device 10 carries out the operation for recording the digital image signals inputted from the inputting terminal for inputting information signals.

[0122] The recording device 10 firstly extracts, from the image signals supplied through the inputting terminal 11 , the copy preventing control information which is added to the image signals (step S 1 ), and determines whether or not the supplied image signals can be copied (step S 2 ). When in the determining step S 2 the copy preventing control information indicates that copying is prohibited, this process is finished without any copying being carried out.

[0123] When in the determining step S 2 the extracted copy preventing control information indicates that copying of the supplied information signals is allowable, or allowable for only first generation, the serial number recorded in the TOC of the disc 100 on which the image signals are to be recorded is read as the medium intrinsic information (step S 3 ), and the read medium intrinsic information is spectrum-spread (step S 4 ).

[0124] The spectrum-spread medium intrinsic information SB 1 is then superimposed on the image signals recorded on the disc 100 (step S 5 ), and the image signals on which the spectrum-spread medium intrinsic information SB 1 is superimposed are recorded on the disc 100 .

[0125] FIG. 8 is a flowchart for explaining the flow of the action of the reproducing device 20 . The process shown in FIG. 8 is started when, for example, a user of the reproducing device 20 carries out the operation for instructing reproduction of the image signals recorded on the disc 100 set into the reproducing device 20 .

[0126] The reproducing device 20 firstly reads the serial number recorded in the TOC of the disc 100 on which the image signals to be reproduced are recorded, as the medium intrinsic information B 2 , from this disc 100 (step S 11 ). The device 20 then detects the medium intrinsic information B 1 spectrum-spread and superimposed on the image signals read from the disc by inverse spectrum-spreading (step S 12 ), and determines whether or not the read medium intrinsic information B 2 is consistent with the medium intrinsic information B 1 superimposed on the image signals (step S 13 ).

[0127] When in the determining step S 13 it is determined that the medium intrinsic information B 1 is consistent with the medium intrinsic information B 2 , the reproducing device 20 performs reproduction of the image signals and reproduces the image signals recorded on the disc 100 (step S 14 ).

[0128] When in the determining step S 13 it is determined that the medium intrinsic information B 1 is not consistent with the medium intrinsic information B 2 , the reproducing device 20 concludes that the image signals copied on the disc 100 are not signals copied in an ordinary manner so that the device 20 does not perform reproduction of the image signals and further displays a message that the image signals recorded on the disc cannot be reproduced on the LCD. The device 20 then erases the image signals on which the medium intrinsic information B 1 different from the medium intrinsic information B 2 recorded on the disc 100 (step S 15 ) is superimposed.

[0129] As described above, when the individual user uses the recording device 10 to record information signals, such as image signals, which are allowable for copying in an ordinary manner for private use, the medium intrinsic information B 1 superimposed on the information signals recorded on the disc is consistent with the medium intrinsic information which the disc on which the information signals are recorded has. However, when the information signals recorded on the disc are not signals copied in an ordinary manner in the recording device 10 , the medium intrinsic information superimposed on the information signals recorded on the disc is not consistent with the medium intrinsic information which the recording disc on which the information signals are recorded has. Thus, in the reproducing device 20 reproduction is not carried out.

[0130] Thus, even if the information signals are allowable for copying, normal reproduction can be carried out when the signals are copied in an ordinary manner for private use of a user, and further illegal copying in a manner different from the ordinary manner can be prevented.

[0131] The medium intrinsic information superimposed on information signals when they are recorded is spectrum-spread and superimposed on the information signals; therefore, the information signals are not deteriorated and further it is also possible to surely pick up the medium intrinsic information properly superimposed and spectrum-spread, without this medium intrinsic information being altered nor taken off, and carry out collation of the two pieces of the medium intrinsic information in the manner as described above.

[0132] When the medium intrinsic information superimposed on the information signals recorded on the disc is not consistent with the medium intrinsic information of the disc on which these information signals are recorded, the LCD 29 displays the message that the signals cannot be reproduced. However, the invention is not limited to such an embodiment.

[0133] For example, an LED (Light Emitting Diode) and an LED driver are disposed to inform that image signals cannot be reproduced, and the LED may be turned on, or turned on and off when image signals as information signals cannot be reproduced because of inconsistency with the aforementioned two pieces of medium intrinsic information.

[0134] An OSD (On Screen Display) may be used to generate a signal for displaying a message that image signals to be reproduced cannot be reproduced, instead of the image signals to be reproduced, and output it.

[0135] Of course, superimposing may be used to display a message that normal reproduction cannot be carried out because of inconsistency with the aforementioned two pieces of medium intrinsic information in images based on the image signals to be reproduced. In this case, the message may be displayed to conceal a half or more of the area of the image based on the image signal to be reproduced, so that what the image to be watched is can be understood and at the same time the image signal cannot be normally reproduced because of concealment of the image caused by displaying the message.

[0136] When the medium intrinsic information superimposed on the information signals recorded on the disc is not consistent with the medium intrinsic information of the disc on which these information signals are recorded, a sound warning may be given.

[0137] In the first embodiment, the image signals on which the medium intrinsic information different from the medium intrinsic information of the disc 100 , which is recorded on the disc 100 , is superimposed are erased. In this case, however, it is not necessarily erased because the image signals are not reproduced.

[0138] The Second Embodiment

[0139] As will be in detail described later, when information signals are recorded on a recording medium according to the second embodiment, device intrinsic information which is intrinsic to a recording device for recording is added, as information related to the recording device, to the information signals, and then the resultant signals are recorded on a recording medium. As the device intrinsic information, for example, manufacturer's serial number may be used. In the case wherein the information signals recorded on the recording medium are reproduced, the information signals recorded on the recording medium may be reproduced when the device intrinsic information added to the information signals to be reproduced is consistent with the device intrinsic information which a reproducing device for reproducing these information signals has.

[0140] In other words, the second embodiment makes it possible to reproduce information signals only in a recording/reproducing device by which the information signals were recorded, and to copy the information signals only for private use, which is more restrictive for copying than the first embodiment using medium intrinsic information.

[0141] In the second embodiment, a recording device 30 or a reproducing device which will be in detail described below is a device such as a personal computer which can receive and transmit information signals through a network such as Internet, in the same manner as in the first embodiment. The recording device 30 and the reproducing device 40 correspond to a recording system in a device, such as a personal computer, and a reproducing system in the same device, respectively.

[0142] Therefore, in the recording and reproducing devices 30 and 40 according to the second embodiment, the same reference numbers are attached to the same structures/elements as in the recording and reproducing devices 10 and 20 according to the first embodiment, and the explanation thereof will be made simple. In the same manner as in the first embodiment, a recording disc 100 is a disc such as a CD-ROM or a DVD, and information signals to be recorded and reproduced will be described as digital image signals.

[0143] Recording Device 30

[0144] FIG. 9 is a block diagram for explaining the recording device 30 in the second embodiment. As shown in FIG. 9 , the recording device 30 has an inputting terminal 11 for inputting information signals, a copy preventing control information detecting section 12 , a timing generator 13 , an SS additional generator 14 , an SS additional information superimposing section 15 , a writing section 16 and a system controller 200 for controlling the respective sections in the recording device 30 .

[0145] As described above, the recording device 30 has a structure that does not comprise the medium intrinsic information reading section 17 which the recording device 10 in the first embodiment has.

[0146] When a user gives an instruction for starting recording image signals through an operation key section 201 connected to the system controller 200 , the system controller 200 controls the respective sections in the recording device 30 to start recording the supplied information signals on the disc 100 .

[0147] In the same manner as in the recording device 10 , signal image signals S 1 transmitted through a network such as Internet and received by the recording device 30 are supplied to the copy preventing control information detecting section 12 , the timing generator 13 and the SS additional information superimposing section 15 in the recording device 30 .

[0148] As described above, the copy preventing control information detecting section 12 detects the copy preventing control information according to the CGMS added to the supplied digital image signals S 1 and informs the system control 200 of the detected copy preventing control information.

[0149] When the copy preventing control information from the copy preventing control information detecting section 12 indicates that any copying is prohibited, the system controller 200 controls the respective sections not to record the digital image signals S 1 . When the information from the copy preventing control information detecting section 12 indicates that copying is allowable, the system controller 200 controls the respective sections in the recording device 30 to record the digital image signals S 1 on the recording medium 100 .

[0150] To the system controller 200 , a ROM 202 and a RAM 203 , as well as the operation key section 201 , are connected. In the ROM 202 , programs which are carried out in the system controller 200 , data for various processes, and information such as manufacturer's serial number of the recording device 30 are recorded. The RAM 203 is used as a working area, for example, for storing results obtained in the middle of processing.

[0151] The manufacturer's serial number of the recording device 30 , recorded on the ROM 202 which the system controller 200 has is a number intrinsic to the recording device 30 and is not the same as that of any other recording device. As will be in detail described later, therefore, in the second embodiment the manufacturer's number stored in the ROM 202 is used as device intrinsic information, which is information related to the device.

[0152] In the second embodiment, when the digital image signals S 1 supplied to the recording device 30 are signals which can be copied, the system controller 200 reads device intrinsic information D 1 intrinsic to the recording device 30 from the ROM 202 , and then supplies the device intrinsic formation D 1 to the SS additional information generator 14 .

[0153] As described above with reference to FIG. 2 , the timing generator 13 detects reference timing signals from the supplied digital image signals S 1 , and generates timing signals TM and clock signals CLK for use in the respective sections in the recording device 10 according to the first embodiment, on the basis of the detected reference timing signals.

[0154] Namely, on the basis of the synchronous signals DK extracted from the digital image signals S 1 the timing generator 13 generates timing signals TM and clock signals CLK in synchronization with the synchronous signals DK in the same manner as in the first embodiment.

[0155] In the SS additional information generator 14 , the timing signals TM are used as reset (initializing) signals for giving timing for generating a PN code series from the head of the series, the PN code series having a predetermined code pattern which is used for spectrum-spreading. The clock signals CLK are used as signals for giving PN code-generating timing. As shown in FIG. 9 , the timing signals TM and the clock signals CLK generated in the timing generator 13 are supplied to the SS additional information generator 14 .

[0156] The SS additional information generator 14 receives the supply of the device intrinsic information D 1 , the timing signals TM and the clock signals CLK, and then generates SS device intrinsic information SD 1 , which is spectrum-spread device intrinsic information D 1 .

[0157] As described above with reference to FIG. 3 , the SS additional information generator 14 has the PN code generator 141 and the multifier 142 . The spread spectrum signals (SS device intrinsic information) SD 1 , which are spectrum-spread device intrinsic information, are generated by multiplying a PN code series PS generated, at every timing that the timing signal TM is supplied, from its head in synchronization with the clock signals CLK, and a device intrinsic information row D 1 R generated, at every timing that the timing signal TM is supplied, by outputting the device intrinsic information D 1 in such a manner that bits thereof corresponding to the predetermined number of clocks are outputted in synchronization with the clock signals CLK. The SD 1 is supplied to the SS additional information superimposing section 15 .

[0158] The SS additional information superimposing section 15 receives the supply of the digital image signals S 1 and the digital SS device intrinsic information SD 1 , and then generates digital image signals S 2 on which the digital SS device intrinsic information SD 1 is superimposed to supply it to the writing section 16 . The writing section 16 receives the supply of the digital image signals S 2 on which the digital SS additional information SD 1 is superimposed and then converts this into recording digital image signals suitable for recording to write the recording digital image signals on the recording medium 100 . Thus, on the recording medium 100 , recorded are the digital image signals on which the SS device intrinsic information SD 1 , which is spectrum-spread device intrinsic information, is superimposed.

[0159] As described above, when information signals that are allowable for copying are copied for private use, in the recording device 30 according to the second embodiment, the device intrinsic information is spectrum-spread and superimposed on the information signals to be copied and subsequently the resultant signals are recorded on the recording medium.

[0160] Reproducing Device 40

[0161] The following will describe the reproducing device 40 according to the second embodiment.

[0162] FIG. 10 is a block diagram for explaining the reproducing device 40 . As shown in FIG. 10 , the reproducing device 40 has a reading section 21 , an SS additional information detecting section 23 , a timing generator 24 , a reproduction allowance/prohibition determining section 25 , a reproduction processing section 26 , an indicative information generator 27 , an LCD (Liquid Crystal Display) driver 28 , an LCD 29 , and a system controller 200 for controlling the respective sections in the reproducing device 40 .

[0163] In short, the reproducing device 40 according to the second embodiment does not have the medium intrinsic information reading means 22 which the reproducing device according to the first embodiment has. The reproducing device 40 can reproduce and output digital image signals recorded on the disc 100 by, for example the aforementioned recording device 30 . Namely, the reproducing device 40 can reproduce digital image signals on which spectrum-spread device intrinsic information is superimposed.

[0164] In the same manner as the reproducing device 20 according to the first embodiment, the reproducing device 40 detects the device intrinsic information superimposed on the digital image signals S 12 read from the disc 100 by carrying out inverse spectrum-spreading in the SS additional information detecting section 23 .

[0165] In other words, the SS additional information detecting section 23 receives the supply of clock signals CLK and timing signals TM which are generated in the timing generator 24 and synchronized with synchronous signals DS detected from the digital image signals 12 , and then generates a PN code series for inverse-spreading having the same code pattern as the PN code series for spectrum-spreading the device intrinsic information D 1 spectrum-spread and superimposed on the digital image signals S 12 , with their generating timing being consistent.

[0166] The SS additional information detecting section 23 carries our inverse spectrum-spreading by using this PN code series for inverse-spreading, so as to detect the intrinsic information D 1 superimposed on the digital image signals S 12 from the signals S 12 . The device intrinsic information D 1 detected from the SS additional information detecting section 23 is supplied to the reproduction allowance/inhibition determining section 25 .

[0167] The system controller 200 reads the manufacturer's serial number of the reproducing device 40 from the ROM 202 which the system controller 200 has, as the device intrinsic information D 2 , and then supplies this to the reproduction allowance/inhibition determining section 25 .

[0168] The reproduction allowance/inhibition determining section 25 determines whether or not the device intrinsic information D 1 superimposed on the digital image signals S 12 read from the disc 100 and supplied from the SS additional information detecting section 23 is consistent with the device intrinsic information D 2 read from the ROM 202 by the system controller 200 and then generates a control signal CT 1 or CT 2 according to the determined result, to supply it to the reproduction processing section 26 and the indicative information generator 27 .

[0169] In other words, when the device intrinsic information D 1 from the SS additional information detecting section 23 is consistent with the device intrinsic information D 2 from the system controller 200 , the reproduction allowance/prohibition determining section 25 concludes that the image signals recorded on the disc 100 are signals copied in the information signal recording/reproducing device having the recording device 30 and the reproducing device 40 according to the second embodiment, and then generates the control signal CT 1 that reproduction is allowable to supply this to the reproduction processing section 26 .

[0170] When the control signal CT 1 from the reproduction allowance/prohibition determining section 25 is the signal that reproductio