JP2004030836A - Write-in data processor for optical disk, optical disk recording device, write-in data generating method, program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a write-in data processor for an optical disk, wherein key information is provided without separately preparing a device for printing, and storing the key information, and also without any possibility of losing the key information. <P>SOLUTION: In the write-in data processor for the optical disk, wherein data to be written are supplied to an optical disk recording device for recording data and images by irradiating an allochromatic layer of the optical disk with a laser beam, write-in data are generated by applying the restriction that the data can not be reproduced if there is no key information to the data to be recorded, and the key information is imageed to generate key image data, then the write-in data and the key image data are outputted, and these write-in positions are instructed so that these positions are not overlapped. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for providing key information corresponding to data recorded on an optical disc.
[0002]
[Prior art]
Conventionally, recordable optical disks such as CD-R (Compact Disc-Recordable) and CD-RW (Compact Disc-Rewritable) have been sold. When recording various data such as music data on these optical disks, an optical disk recording device such as a CD-R drive device or a CD-RW drive device is used. In these optical disk recording apparatuses, information recording is performed by irradiating a recording surface with laser light corresponding to information to be recorded. Since such information recording can be performed very easily, a CD-R or CD-RW is stored in a storage medium such as a CD-ROM (Compact Disc-Read Only Memory) on which music, program software, etc. are recorded. Copying data to is a popular activity.
[0003]
In order to prevent illegal data copying, for example, there is a technique for restricting the use of data as described below. This is a technique in which data is encrypted and recorded on a CD-ROM or the like, and when the data recorded on the CD-ROM is reproduced, encryption key information is input to decrypt the encrypted data. The encryption key information is printed on a sticker and affixed to a storage cassette or the like of the CD-ROM, printed on paper, or recorded as data on another medium.
[0004]
However, as described above, when printing the encryption key information on a sticker or printing on paper, a separate printer device is required, and an operation of printing the encryption key information is required. Further, it is necessary to perform an operation of attaching a seal on which the encryption key information is printed to a storage cassette. Further, if the encryption key information is simply printed on paper, if the paper is lost, the encrypted data may not be decrypted. Further, data recording of the encryption key information on another medium also requires a data recording operation. Then, as in the case of paper, if this medium is lost, the encrypted data may not be able to be decrypted.
[0005]
[Problems to be solved by the invention]
Therefore, the present invention has been made in view of the above circumstances, and without separately preparing a device for printing or storing key information, without fear of loss of key information, An object of the present invention is to provide an information processing apparatus that provides the information.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides an optical disc writing apparatus that supplies data to be written to an optical disc recording apparatus that irradiates a laser beam to a color changing layer of an optical disc to record data and images. In the data processing device,
Data generation means for generating write data by restricting data to be recorded so that reproduction is impossible without key information, and generating key image data by imaging the key information,
Output means for outputting the write data and the key image data and indicating a write position so that these write positions do not overlap
The present invention provides an optical disk write data processing device comprising:
[0007]
According to the optical disk write data processing apparatus, an optical disk write apparatus for supplying data to be written to an optical disk recording apparatus that irradiates a laser beam onto a discoloration layer of an optical disk to record data and images. In the data processing device, data to be recorded is restricted so that it cannot be reproduced without the key information, write data is generated, and the key information is imaged to generate key image data. In addition to outputting the embedded data and the key image data, the writing position is designated so that these writing positions do not overlap.
[0008]
In a preferred embodiment, the key image data may be character image data or barcode data.
[0009]
Further, the present invention provides an optical disc recording means for recording data or forming an image by irradiating a laser beam to the discoloration layer of the optical disc,
Data generation means for generating write data by restricting data to be recorded so that reproduction is impossible without key information, and generating key image data by imaging the key information,
Output means for outputting the write data and key image data to the optical disk recording means and indicating a write position so that these write positions do not overlap
An optical disk recording device characterized by comprising:
[0010]
According to this optical disk recording apparatus, data to be recorded is restricted so that it cannot be reproduced without key information, write data is generated, and the key information is imaged to generate key image data. , And outputs the write data and key image data, and designates a write position so that these write positions do not overlap.
[0011]
Further, the present invention provides a method for creating data to be written on an optical disc when data is recorded or an image is formed by irradiating a laser beam to a discoloration layer of the optical disc,
A data generating step of generating write data by applying a restriction such that data to be recorded cannot be reproduced without key information, and generating key image data by imaging the key information;
An output step of outputting the write data and the key image data and designating a write position so that these write positions do not overlap
And a method for creating write data, comprising:
[0012]
According to this write data creation method, data to be recorded is restricted so that it cannot be reproduced without key information, write data is generated, and the key information is imaged to generate key image data. Then, the writing data and the key image data are output, and a writing position is designated so that these writing positions do not overlap.
[0013]
Further, the present invention provides a program for creating data to be written on an optical disc when recording data or forming an image by irradiating a laser beam to the discoloration layer of the optical disc,
On the computer,
A data generating step of generating write data by applying a restriction such that data to be recorded cannot be reproduced without key information, and generating key image data by imaging the key information;
An output step of outputting the write data and the key image data and designating a write position so that these write positions do not overlap
And a writing data creation program characterized by executing the following.
[0014]
According to this program, data to be recorded is restricted so that it cannot be reproduced without key information, write data is generated, and the key information is imaged to generate key image data. The writing data and the key image data are output, and a writing position is designated so that these writing positions do not overlap.
[0015]
Further, according to the present invention, there is provided a storage medium storing the above-mentioned program.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. These embodiments show one aspect of the present invention, and do not limit the present invention, and can be arbitrarily changed within the scope of the present invention.
(1) Configuration
The optical disc recording apparatus according to the present embodiment has a function of irradiating a recording surface of an optical disc with laser light to record encrypted data and forming encryption key information for decrypting the data as a visible image. Have.
FIG. 1 is a diagram schematically showing an optical disc 200 on which the encrypted key information is formed as a visible image together with the recording of the encrypted data by the optical disc recording apparatus having such a function. As shown in the figure, on the recording surface of the optical disc 200, in a data recording area 200a surrounded by a dashed line in the figure, an area 200b is encrypted by encryption key information from the inner side to the outer side. Recorded data. Then, in the area 200c outside the area where the data is stored, the encryption key is visually image-formed from the outer peripheral side toward the inner peripheral side. In the figure, “012 # ABC? A” corresponds to this encryption key.
Hereinafter, a configuration of an optical disk recording apparatus capable of recording data and forming a visible image on the optical disk 200 will be described.
[0017]
(1) Configuration of optical disk recording device
FIG. 2 is a block diagram showing the configuration of the optical disk recording device according to one embodiment of the present invention. As shown in the figure, the optical disk recording device 10 surrounded by a dotted line in the figure is connected to a host computer 500 via an interface 150. Then, in accordance with an instruction from the host computer 500, data is recorded on the optical disk or an image is formed.
[0018]
In the figure, a spindle motor 130 rotates the optical disc 200. This optical disc 200 is a target for data recording or image formation.
The rotation detector 132 is a kind of frequency tacho generator that outputs a signal FG having a frequency corresponding to the spindle rotation speed by using a back electromotive current of the spindle motor 130.
Since the optical disk recording device 10 in the present embodiment employs the CAV (Constant Angular Velocity) method, the rotation speed of the spindle motor 130 detected by the signal FG becomes the angular speed AV instructed by the main control unit 170. As described above, feedback control is performed by the servo circuit 138.
The rotation direction is controlled so as to be counterclockwise when viewed from the recording surface when recording data, and to be clockwise when viewed from the recording surface when forming images. This is because the data is recorded from the inner circumference to the outer circumference during data recording, whereas the image is formed from the outer circumference to the inner circumference during image formation. . By performing such control, it becomes easier to perform both data recording and image formation on the recording surface.
Note that the servo circuit 138 performs tracking control and focus control for the optical pickup 100 in addition to rotation control for the spindle motor 130.
[0019]
The optical pickup 100 irradiates a rotating optical disc 200 with laser light. The detailed configuration is shown in FIG. As shown in FIG. 1, the optical pickup 100 includes a laser diode 102 for emitting a laser beam, a diffraction grating 104, an optical system 110 for condensing the laser beam on the surface of the optical disc 200, and receiving reflected (return) light. And a light receiving element 108 that performs the operation.
[0020]
The laser diode 102 emits a laser beam with an intensity corresponding to the current value of the drive current Li output from the laser driver 164 (see FIG. 2). The laser beam emitted from the laser diode 102 is separated into a main beam and two sub-beams by a diffraction grating 104, and then a polarization beam splitter 111 constituting an optical system 110, a collimator lens 112, and a 1/4 The light passes through the wave plate 113 and the objective lens 114 in order, and is condensed on the optical disc 200.
On the other hand, the three laser beams reflected by the optical disk 200 pass through the objective lens 114, the quarter-wave plate 113, and the collimator lens 112 again in this order, are reflected at right angles by the polarization beam splitter 111, and pass through the cylindrical lens 115. Are incident on the light receiving element 108.
The light receiving signal Rv from the light receiving element 108 is amplified by an RF (Radio Frequency) amplifier 134 (see FIG. 2) and then supplied to the servo circuit 138 and the decoder 136.
[0021]
The objective lens 114 is held by a focus actuator 121 and a tracking actuator 122 and can move in the optical axis direction of the laser beam and in the radial direction of the optical disc 200.
The focus actuator 121 moves the objective lens 114 in the optical axis direction according to the focus signal Fc supplied from the servo circuit 138 (see FIG. 2).
The tracking actuator 122 moves the objective lens 114 in the radial direction of the optical disc 200 according to the tracking signal Tr supplied from the servo circuit 138 (see FIG. 2).
[0022]
The optical pickup 100 has a front monitor diode (not shown) for monitoring the laser light of the laser diode 102. A current Fi corresponding to the amount of light emitted from the laser diode 102 is output from the front monitor diode and supplied to the laser power control circuit 162 shown in FIG. The laser power control circuit 162 refers to the target value REF supplied from the main control unit 170 and supplies the laser driver instruction value LP to the laser driver 164. The laser driver 164 outputs a drive current Li according to the instruction value LP. With the above configuration, a feedback loop of laser power is configured.
[0023]
The motor driver 142 receives a signal for moving the optical pickup 100 in the radial direction of the optical disc 200 from the main control unit 170, and supplies a driving current corresponding to the signal to the stepping motor 140.
Here, in the present embodiment, as described above, since the CAV method is used in which the angular velocity is constant, the linear velocity increases toward the outside of the optical disc 200. For this reason, the main control unit 170 sets the intensity of the laser beam to be higher as the optical pickup 100 is located outside the optical disc 200.
[0024]
The decoder 136 performs EFM demodulation on the light receiving signal Rv supplied from the RF amplifier 134 and supplies the signal to the main controller 170.
[0025]
Next, the buffer memory 152 stores information supplied from the host computer 500 via the interface 150, that is, data to be recorded on the optical disk 200 (hereinafter, referred to as recording data) in a FIFO (first in first out) format.
[0026]
The encoder 154 performs EFM modulation on the recording data read from the buffer memory 152 and outputs the recording data to the strategy circuit 156.
The strategy circuit 156 performs a time axis correction process or the like on the EFM signal supplied from the encoder 154, and outputs the result to the laser driver 164.
[0027]
On the other hand, the frame memory 158 stores image data for visually indicating the encryption key information on the optical disc 200. This image data is generated by the host computer 500 and supplied to the optical disk recording device 10 via the interface 150.
[0028]
<Structure of image data>
Here, first, the recording surface of the optical disc 200 will be briefly described. FIG. 4 is a diagram schematically showing the recording surface of the optical disc 200. On the recording surface of the optical disc 200, one groove 202a is formed in a spiral shape clockwise from the inner peripheral side. When data is recorded on the optical disc 200, a laser beam is irradiated from the inner circumference to the outer circumference along the groove 202a. In the present embodiment, when a visible image is formed, laser light is emitted from the outer periphery to the inner periphery along the groove 202a of the recording layer 202.
[0029]
Based on the above, image data for visually displaying the encryption key information on the optical disc 200 will be described next.
This image data is a set of information indicating whether or not thermal discoloration is performed for each dot to be drawn on the disk-shaped optical disk 200. As shown in FIG. 5, the positions of the dots P are arranged corresponding to the respective intersections between the groove 202a and the radiation from the center of the optical disc 200.
[0030]
The reason for such an arrangement is as follows. In the present embodiment, during data recording, the optical disc 200 rotates counterclockwise as viewed from the recording surface, while causing the optical pickup 100 to rotate from the inner circumference to the outer circumference in order to trace from the inner end point Gs of the groove 202a. It is configured to move toward the side. On the other hand, when an image is formed on the optical disc 200, the image is formed from the outer circumference toward the inner circumference along the groove 202a of the optical disc 200. For this reason, at the time of image formation, the optical disc 200 is rotated clockwise, which is opposite to that at the time of data recording.
[0031]
In the present embodiment, the last m rows are set to correspond to positions at a distance of about 42 mm from the center of the optical disc 200. That is, an area having a distance from the center of the optical disc 200 of about 42 mm to 58 mm is defined as an area for image formation. The data recording area is an area having a distance from the center of the optical disc 200 of about 25 mm to 40 mm with a margin so that image formation and data recording do not overlap. However, this region setting is in the present embodiment, and various settings are possible in the embodiment of the present invention.
[0032]
When defined in this manner, the dot data is stored in the frame memory 158 corresponding to the arrangement of m rows and n columns, as shown in FIG. Here, dot data = '1' indicates that the color is thermally discolored, and dot data = '0' indicates that the color is not thermally discolored. That is, dot data = “1” indicates that the recording level laser light is irradiated, and dot data = “0” indicates that the servo level laser light is irradiated.
Note that the recording level laser light is a laser light having sufficient intensity to thermally discolor the recording surface, and the servo level laser light is used for focus control and light amount control on the recording surface. This is a laser beam that can be irradiated, and does not cause thermal discoloration on the recording surface.
That is, by irradiating the laser light in accordance with the dot data, a thermally discolored portion and a non-thermally discolored portion are formed on the recording surface of the optical disc 200. An image is visually represented by the color contrast between the thermally discolored portion and the non-thermally discolored portion.
[0033]
Then, in the process of forming an image on the optical disc 200, the image data is read from the frame memory 158 and supplied to the laser driver 164. More specifically, when a row and a column are designated by the main control unit 170, one dot data corresponding to the row and the column is read out from the image data stored in the frame memory 158, and the laser driver 164.
[0034]
FIG. 5 is only a schematic diagram showing the positional relationship between the dots P, and actual dots are densely arranged. The same applies to the pitch of the groove 202a in FIGS.
The image data used in the host computer 500 is generally in a bitmap format. For this reason, when an image is formed on the optical disc 200, the image data in the bitmap format is converted by the host computer 500 into a coordinate system as shown in FIG. May be stored in the frame memory 158 (see FIG. 2) as data as shown in FIG.
[0035]
The laser driver 164 controls the laser power control circuit 162 according to the modulation data supplied from the strategy circuit 156 during data recording and according to the image data supplied from the frame memory 158 during image formation. Is generated and supplied to the laser diode 102 of the optical pickup 100.
[0036]
The rotation detector 132 outputs a signal FG having a frequency corresponding to the rotation speed of the spindle motor 130, as described above.
The PLL (Phase Locked Loop) circuit 144 generates a clock signal Dck which is synchronized with the signal FG and whose frequency is multiplied, and supplies the clock signal Dck to the main control unit 170. Further, the frequency dividing circuit 146 generates a reference signal SFG obtained by dividing the signal FG by a fixed number, and supplies the reference signal SFG to the main control unit 170.
[0037]
Here, assuming that the rotation detector 132 generates eight pulses as the signal FG during the rotation of the spindle motor 130, that is, one rotation of the optical disc 200, as shown in FIG. The signal 146 divides the signal FG by ８ and outputs the signal FG as a reference signal SFG. Accordingly, the main control unit 170 can detect the rising timing of the reference signal SFG as the timing at which the irradiation position of the laser beam by the optical pickup 100 has passed the reference line of the optical disc 200.
[0038]
Also, in this case, if the frequency multiplication factor in the PLL circuit 144 is set to the value of the quotient obtained by dividing the number of columns n per row n (see FIG. 5) by 8, one cycle of the clock signal Dck becomes Coincides with a period in which the dot is rotated by an angle corresponding to one row of the dot array.
Therefore, the main control unit 170 sequentially counts the rising timing of the clock signal Dck after the rising of the reference signal SFG, so that the laser beam irradiation position of the optical pickup 100 is adjusted to the reference line of the optical disc 200 at the time of image creation. , It is possible to detect the number of the column after passing.
[0039]
It should be noted that the expression “reference line” of the optical disc 200 should be accurately referred to as a reference line with respect to the rotation axis of the spindle motor 130. However, during data recording or image formation, the optical disc 200 rotates while being chucked on a table directly connected to the rotation axis. Maintain a certain positional relationship with one of the radiations. Therefore, as long as the state is maintained, one radiation on the optical disc 200 may be called a reference line of the optical disc 200.
Further, in the present embodiment, the rising timing of the reference signal SFG is set as the reference line passing timing of the optical disc 200, and the rising timing of the clock signal Dck is set as the timing rotated by an angle of one line of the dot array. However, in any case, the rising timing may be used.
What has been described above is the configuration of the optical disk recording device 10 according to the present embodiment.
[0040]
(2) Configuration of host computer 500
FIG. 13 is a block diagram showing a configuration of the host computer 500. As shown in the figure, each unit of the apparatus is connected via a bus 507. Hereinafter, each part of the apparatus will be described in detail.
[0041]
The control unit 501 controls each unit of the apparatus, performs data transmission, performs various calculations, temporarily stores data, and the like.
[0042]
A ROM (Read Only Memory) 505 stores various programs executed by the control unit 501, various data, and the like. For example, the ROM 505 stores a program for encrypting data to be recorded, a program for generating image data, a program for decrypting encrypted data, and the like.
[0043]
The RAM 506 is used as a work area of the control unit 501, and temporarily stores a program executed by the control unit 501 and various data.
[0044]
The operation unit 502 includes a plurality of keys for inputting numbers, characters, operation instructions, and the like, and outputs an operation signal corresponding to the operation of these keys to the control unit 501.
[0045]
The display unit 503 includes a medium for displaying information, such as a liquid crystal display panel or a CRT display, and a drive circuit for controlling display of the display medium.
[0046]
The interface 504 controls communication performed between the host computer 500 and the optical disk recording device 10.
[0047]
(2) Operation
<Recording operation>
Next, the operation of the optical disc recording device 10 according to the present embodiment will be described. FIG. 8 is a timing chart showing a flow of a process of encrypting data to be recorded on the optical disk 200 based on the encryption key information, recording the data on the optical disk 200, and forming the encryption key information as an image.
First, the user operates the operation unit 502 of the host computer 500 to input data to be recorded on the optical disc 200 (step S10). Next, the control unit 501 of the host computer 500 requests the user to input the encryption key information. The operator inputs the encryption key.
When detecting the input of the encryption key information (step S11), the control unit 501 encrypts the target data according to the encryption key information and the encryption rule stored in advance (step S12).
[0048]
Note that encrypting data means processing data using a specific encryption rule. This makes it possible for a third party who does not know the algorithm of the encryption rule to know the contents of the original data. The specific encryption rule is that, for example, the original data is divided into groups of several bits, and each bit is shifted right or left by several bits within this group. At this time, the encryption key information specifies how many bits of the original data are divided into groups, how many bits are shifted within the group, or whether to shift right or left. Is a sequence of numbers. In addition, by using the encryption key information and going through a procedure reverse to the encryption processing, the encrypted data can be decrypted. There are various rules for encrypting such data, and in the present embodiment, there is no limitation on what encryption rule is used to encrypt data. A desired encryption rule is stored in the control unit 501 of the host computer 500 in advance.
[0049]
Then, when the encryption of the target data is completed, the control unit 501 transfers the encrypted data to the optical disk recording device 10 via the interface 504 together with the data recording instruction (step S13).
[0050]
When the main control unit 170 of the optical disc recording device 10 receives data to be recorded together with a data recording instruction from the host computer 500 via the interface 150, the main control unit 170 stores the data in the buffer memory 152. Next, a process of recording the data on the optical disc 200 is started as follows (step S14).
First, the spindle motor 130 instructs the servo circuit 138 to rotate at a predetermined angular velocity counterclockwise as viewed from the recording surface. The servo circuit 138 controls the spindle motor 130 to rotate at the designated rotational direction and angular velocity.
[0051]
Next, the main controller 170 instructs the motor driver 142 to move the optical pickup 100 to a point corresponding to the innermost circumference of the groove 202a. The motor driver 142 rotates the stepping motor 140 according to the instruction, and thereby moves the optical pickup 100 to a point corresponding to the innermost circumference of the recording area.
Then, the servo circuit 138 performs tracking control, thereby starting tracing of the groove 202a, and reads out the recording data stored in the buffer memory 152. The encoder 154 performs EFM modulation on the read data, and the strategy circuit 156 performs a time axis correction process or the like on the EFM modulated data. Then, in accordance with the data subjected to the EFM modulation, the laser diode 102 irradiates a laser beam of a recording level along the groove 202a. The recording layer 202 irradiated with the laser beam at the recording level is degraded, whereby data is recorded. By performing such an operation, the main control unit 170 first records the lead-in information on the optical disc 200, and then records the EFM-modulated data in the data recording area.
[0052]
At the time of recording such data, various controls such as rotation control, tracking control, light quantity control, sled control, and focus control are executed as is well known.
When the data recording is completed, the motor driver 142 again rotates the stepping motor 140 to move the optical pickup 100 to a point corresponding to the innermost circumference of the recording area. Then, the address AD of the recording end point of the data is recorded in the lead-in information. This address corresponds to a radius r from the center of the optical disc 200.
Then, the main control unit 170 transfers a data recording end signal to the host computer 500.
[0053]
On the other hand, when receiving the data recording end signal, the control unit 501 of the host computer 500 starts a process of forming an image corresponding to the encryption key information on the optical disc 200 (step S15). First, image data creation processing corresponding to the following encryption key information is performed. Based on the input encryption key information, as shown in FIG. 6, one character is decomposed into 7 rows and 3 columns of dots to generate dot data represented by 1 or 0. For example, the set of dot data indicated by reference sign A is obtained by decomposing '0', and the set of dot data indicated by reference sign B is obtained by decomposing '1'. As described above, image data composed of dots in m rows and n columns is generated. However, as described above, since the optical pickup 100 traces the groove 202a of the optical disc 200 counterclockwise from the outer circumference side, when generating image data, the encryption key is moved from the last n-th column to the first column. Dot data corresponding to each character included in the information is generated.
Then, when the generation of the image data corresponding to the encryption key information is completed, the control unit 501 transfers the image data to the optical disk recording device 10 together with the image formation instruction (step S16).
[0054]
When the main control unit 170 of the optical disc recording apparatus 10 receives the image data together with the image formation instruction, the main control unit 170 stores the image data in the frame memory 158. Next, the main controller 170 starts the image forming process of the encryption key information (Step S17). 9 and 10 show detailed sequence charts of the image forming process (step S17).
[0055]
First, the main control unit 170 instructs the servo circuit 138 to rotate the spindle motor 130 at a predetermined angular speed counterclockwise as viewed from the recording surface. Next, the motor driver 142 is instructed to move the optical pickup 100 to a point corresponding to the innermost circumference of the groove 202a. The motor driver 142 rotates the stepping motor 140 according to the instruction, and thereby moves the optical pickup 100 to a point corresponding to the innermost circumference of the recording area. Then, the servo circuit 138 performs tracking control, thereby starting tracing of the groove 202a, and irradiating the laser diode 102 with a laser beam of reproducing power. The light receiving signal Rv thus obtained is amplified by the RF amplifier 134, and the amplified signal is supplied to the decoder 136 and the decoder 136. The decoder 136 performs EFM demodulation on this and supplies it to the main control unit 170. As described above, the main control unit 170 first obtains the lead-in information recorded on the optical disc 200, and indicates the address AD of the recording end point of the data recorded on the optical disc 200 indicated by this information. That is, a radius r from the center of the optical disc 200 is obtained (step S170).
[0056]
Next, the main controller 170 determines whether or not the radius r is smaller than 40 mm (step S171). If the result of this determination is negative, image formation of the encryption key information on the optical disk 200 is not permitted, and a message signal to that effect is output (step S173).
[0057]
On the other hand, if the determination result is affirmative, the image formation of the encryption key information on the optical disk 200 is permitted, and the servo motor 138 is caused to rotate the spindle motor 130 clockwise as viewed from the recording surface at a predetermined angular velocity. An instruction is given (step S172). The servo circuit 138 controls the spindle motor 130 to rotate at the designated rotational direction and angular velocity.
[0058]
By such an operation, the optical disc 200 rotates clockwise when viewed from the recording surface, unlike during data recording, whereby the optical pickup 100 moves the groove 202a from the outer peripheral side to the inner peripheral side of the optical disc 200. Can be traced.
[0059]
Next, the main control unit 170 instructs the motor driver 142 to move the optical pickup 100 to a point corresponding to the outermost periphery (first row) of the storage area of the optical disc 200. The motor driver 142 rotates the stepping motor 140 in accordance with the instruction, thereby moving the optical pickup 100 to a point corresponding to the outermost periphery of the recording area (step S174).
Next, the main control unit 170 processes the dot data column corresponding to the first column in order to sequentially process the first to last n columns in the row where the optical pickup 100 is located (see FIG. 11). Is started (step S175).
[0060]
Then, the main control unit 170 waits until the reference line of the rotating optical disc 200 passes a specific position, that is, until the rising timing of the reference signal SFG comes (step S176).
[0061]
Then, when the reference signal SFG rises, the main control unit 170 performs tracking control, and thereby starts tracing the groove 202a. Further, the following processing is executed in synchronization with one cycle of the clock signal Dck. The main control unit 170 reads out the dot data of the row to be processed in the row where the optical pickup 100 is currently located from the frame memory 158. The laser driver 164 determines whether or not the read dot data is “1” (Step S177).
[0062]
If the result of this determination is affirmative, a drive current Li corresponding to the recording level is output (step S178). As a result, the laser diode 102 in the optical pickup 100 irradiates the laser light at the recording level, so that the portion of the recording layer 202 of the optical disc 200 where the irradiation light from the optical pickup 100 is located undergoes thermal discoloration.
[0063]
On the other hand, if the determination result in step S179 is negative, the laser driver 164 outputs the drive current Li corresponding to the servo level (step S179). Thereby, the laser diode 102 in the optical pickup 100 irradiates the laser light of the servo level, so that the recording layer 202 does not undergo thermal discoloration. At this time, the laser light at the servo level is irradiated to perform focus control and light amount control.
As described above, the processing of the portion corresponding to the first column and the first row of the recording layer 202 of the optical disc 200 is performed.
[0064]
Thereafter, similarly, the processing of each column is performed in the order of the second column, the third column,... Of the same row (the first row at this stage). That is, the main control unit 170 determines whether or not the processing target column is the last n columns (step S180). If “No”, the process proceeds to step 181 to set the processing target column to the next column. Returning to step S177, the loop of steps S177 → S178 (or S179) → S180 → S181 → S177 is repeated until the last column (n-th column) is reached. By this loop processing, the drawing processing of the first line is performed.
[0065]
Then, when the processing of the last row is completed, the determination in step S180 becomes “Yes”, and the flow proceeds to the determination in step S182. In step S182, it is determined whether or not it is the last row. If "No", the processing target row is changed to the next row in step S183. Then, in step S176, the timing of passing the reference position is adjusted, and the loop of steps S177 → S178 (or S179) → S180 → S181 → S177 is repeated again. The drawing processing of the second line is performed by this loop processing.
[0066]
In the same manner, the above processing is repeated until the determination in step S182 becomes “Yes”. Thereby, the first row to the n-th column in the first row, the first column to the n-th column in the second row, the first column to the n-th column in the third row, and so on. Then, image formation is sequentially performed.
[0067]
If it is determined in step S182 that the row where the optical pickup 100 is located is the last m row, it is determined that all the image formation from the first row to the last m row is completed for the optical disc 200. Therefore, the image forming process is terminated.
[0068]
Through the above operation, the encrypted data on the optical disk 200 and the encryption key information for decrypting the encrypted data are visually formed. FIG. 11 shows an example.
[0069]
<Playback operation>
As described above, the reproduction process of the optical disc 200 on which the encrypted data is recorded and the encryption key is formed is as follows.
When the user performs a predetermined operation on the operation unit 502 of the host computer 500 and instructs to reproduce data recorded on the optical disc 200, the control unit 501 starts the following data reading process. Here, FIG. 12 is a timing chart of the data read processing. First, the user is prompted to input the encryption key information. Then, when the user visually reads the encryption key from the image drawn on the optical disc 200 and inputs it by operating the operation unit 502, the control unit 501 detects this and temporarily stores the encryption key information in the RAM 506. (Step S20).
[0070]
In addition, it instructs the optical disc recording device 10 to read data recorded on the optical disc 200 via the interface 504. When the main control unit 170 of the optical disk recording device 10 detects an instruction to read data via the interface 150, it drives the servo circuit 138 to rotate the spindle motor 130 and rotate the optical disk 200. Further, the main controller 170 instructs the laser driver 164 via the laser power control circuit 162 to read data recorded on the optical disc 200 (step S21). The laser driver 164 supplies a drive current Li for irradiating the optical pickup 100 with laser light of a reproduction level.
[0071]
As a result, the optical pickup 100 appropriately moves in the radial direction of the optical disc 200, irradiates the optical disc 200 with a laser beam of a reproduction level, thereby obtaining a light receiving signal Rv, and supplies the light receiving signal Rv to the RF amplifier 134. I do. The RF amplifier 134 amplifies the supplied light receiving signal Rv, and supplies the amplified signal to the decoder 136 and the servo circuit 138. The decoder 136 performs EFM demodulation on this and supplies it to the main control unit 170. The main controller 170 transfers the read data subjected to the EFM demodulation to the host computer 500 via the interface 150 (Step S22).
[0072]
Upon receiving the read data of the data recorded on the optical disc 200 via the interface 504, the control unit 501 of the host computer 500, as described above, temporarily stores the temporarily stored encryption key information and the previously stored encryption key information. The read data is decoded based on the rules (Step S23). If correct encryption key information is not input to the data recorded on the optical disc 200, correct data cannot be obtained even if the data is decrypted.
[0073]
In the present embodiment, when decrypting the encrypted data, the user only needs to refer to the encryption key information formed on the optical disc 200, so that it does not take much trouble and unless the optical disc 200 is lost, There is no danger of losing the encryption key information.
When the optical disk 200 is to be copied to another optical disk 200, the encrypted data recorded on the optical disk 200 can be copied, but the encryption key information formed on the optical disk 200 cannot be copied. Because it is not possible, it leads to suppression of piracy.
[0074]
In the above-described operation, the image forming process of the encryption key information is performed immediately after the process of recording the encrypted data on the optical disc 200. However, the process of recording the encrypted data is performed as an independent process. good. Then, the image forming process of the encryption key information on the optical disc 200 may be newly started as a separate process. The encryption key information may not be input by the user, but may be automatically generated by the control unit 501 of the host computer 500 using, for example, the start time, the data amount of the corresponding data, and the like as arguments. .
[0075]
Before recording the encrypted data on the optical disc 200, the control unit 501 of the host computer 500 detects the data amount of the data and calculates in advance the address AD of the recording end point corresponding to the data amount. You may do it. According to such a configuration, before recording the encrypted data on the optical disc 200, it can be determined whether or not there is an area for image formation. Therefore, for example, while the optical disk recording device 10 is recording the encrypted data, the control unit 501 of the host computer 500 may perform the image data generation processing corresponding to the encryption key information corresponding to the data. The image forming process can be performed efficiently.
[0076]
(3) Modified example
<Use encryption key information other than sequence>
The encryption key information may be a number, a character, a symbol, a combination thereof, or may be a one-dimensional barcode or a two-dimensional barcode. Furthermore, images other than these may be used.
For example, when forming a two-dimensional barcode on the optical disc 200, when the user inputs desired encryption key information at the start of the above-described data encryption processing, the control unit 501 of the host computer 500 causes the encryption key information to be Generate a corresponding two-dimensional barcode. The two-dimensional barcode is a barcode display method having information in horizontal and vertical directions, that is, two-dimensional directions. These two-dimensional barcodes are obtained by coding numbers, characters, symbols, and the like according to predetermined coding rules. In this modification, what kind of two-dimensional barcode is used is not limited. However, the control unit 501 of the host computer 500 stores a coding rule for generating a desired two-dimensional barcode in advance. I have. Therefore, the control unit 501 of the host computer 500 converts the input encryption key information into a two-dimensional barcode based on the coding rule. Then, the control unit 501 generates dot data of m rows and n columns corresponding to the two-dimensional barcode, in the same manner as the above-described image data generation processing, by using the two-dimensional barcode thus generated. The data is transferred to the optical disk recording device 10 via the 504. Upon receiving the image data via the interface 150, the optical disk recording device 10 forms an image based on the image data on the optical disk 200, similarly to the above-described image forming process. At this time, it is assumed that the data to be recorded on the optical disk 200 has already been encrypted according to the encryption key information and the encryption rule stored in advance, and has been recorded on the optical disk 200 in the same manner as the above-described recording operation. .
[0077]
On the other hand, when reproducing the encrypted data recorded on the optical disk 200, a host computer 500 having a barcode reader (not shown) is used. First, an image of a two-dimensional barcode formed on the optical disc 200 is read by a barcode reader of the host computer 500. Then, the control unit 501 of the host computer 500 returns the two-dimensional barcode to the original data such as numbers, characters, and symbols based on the coding rule, and temporarily stores the data as encryption key information. Then, similarly to the above-described data reproduction process, the data recorded on the optical disc 200 is read and supplied to the control unit 501 of the host computer 500. Thereafter, the read data is decrypted based on the temporarily stored encryption key information and the previously stored encryption rule.
[0078]
By converting the encryption key information into a two-dimensional barcode as described above, it becomes difficult to copy the two-dimensional barcode by handwriting or the like, and it is possible to further contribute to the suppression of illegal copying of the optical disc 200.
[0079]
When an image other than a two-dimensional barcode is formed on the optical disc 200, the host computer 500 may be provided with a scanner, and the scanner may read the image. Further, the optical disk recording device 10 may be provided with a barcode reader and a scanner. In such a configuration, the optical disk recording device 10 reads the image of the encryption key information formed on the optical disk 200 by a barcode reader or a scanner, and decodes the data recorded on the optical disk 200 based on the image. Perform the conversion.
[0080]
<Verify key information>
Instead of encrypting the data to be recorded on the optical disc 200, access to the data may be managed by key information such as a password, a management number, or an identification number.
Specifically, when recording the data on the optical disc 200, the control unit 501 of the host computer 500 urges the user to input key information, and when the key information is input, the data and the input data are input. The key information is associated with the key information and transferred to the optical disk recording device 10 via the interface 504. The optical disk recording apparatus 10 records the data and the key information on the optical disk 200 in association with each other. The correspondence is stored in the lead-in information. Further, an image corresponding to the key information is formed on the optical disc 200 in the same manner as the above-described image forming process.
[0081]
Then, when an instruction to reproduce the data recorded on the optical disc 200 is given, the control unit 501 of the host computer 500 prompts the user to input key information. When the key information is input, the key information is temporarily stored in the RAM 506. Then, the optical disc recording apparatus 10 is instructed to read the key information recorded on the optical disc 200 as described above. The optical disk recording device 10 reads the key information recorded on the optical disk 200 according to the instruction, and transfers the key information to the control unit 501 of the host computer 500 via the interface 150. The control unit 501 of the host computer 500 determines whether or not the transferred key information matches the temporarily stored key information. If they match, an instruction to read the data is issued to the optical disk recording device 10. If they do not match, the data reading instruction is not performed, and a message signal to that effect is output.
[0082]
Also, regarding the encrypted data, when an instruction to read the encrypted data recorded on the optical disc 200 is given, the encryption key information recorded corresponding to the data is collated with the encryption key information input by the user. You may do it. If the collation result is affirmative, the encrypted data is read from the optical disc 200. If the collation result is negative, the data is not read from the optical disc 200.
In this manner, if the data is read from the optical disc 200 only when correct encryption key information corresponding to the encrypted data is input, the encrypted data is read in accordance with the incorrectly input encryption key information. The useless decoding can be eliminated.
[0083]
Further, as described above, when key information is recorded on the optical disc 200 for collation, the optical disc recording apparatus for performing data recording and the optical disc recording apparatus for performing image formation may be separate apparatuses. After recording data on the optical disk 200, the optical disk 200 is set in an optical disk recording device for forming an image, and the key is recorded on the optical disk 200 based on the key information recorded in the lead-in information as described above. An information image may be formed. Therefore, the optical disc recording apparatus may not have a function of recording data on the optical disc 200, but may have only a function of forming an image on the optical disc 200.
[0084]
<The encrypted data contains a self-restoring decryption program>
When the encrypted data is transferred from the host computer 500 to the optical disk recording device 10, a self-restoration type decryption program may be transferred together. The main control unit 170 of the optical disk recording device 10 records the decryption program on the optical disk 200 together with the transferred encrypted data.
Then, when the data is reproduced, the data read by the optical disk recording device 10 is transferred to the host computer 500 (including the decoding program), and the control unit 501 of the host computer 500 First, a decryption program is activated. Then, the user is prompted to input the encryption key information corresponding to the encrypted data. When the encryption key information is input, the transferred encrypted data is decrypted based on the encryption key information and the decryption program.
[0085]
<Do not use grooves>
In the image forming process, the configuration may be such that the groove 202a is not used, that is, tracking control is not performed. In such a configuration, when the rotation direction of the optical disc 200 is considered to be the main scanning direction and the radial direction is considered to be the sub-scanning direction, the tracking position is not controlled, and the irradiation position of the laser beam is moved in the radial direction by the required amount in the The means for causing the optical pickup 100 to move by the rotation of the stepping motor 140 is configured. In this case, since the dots of the recorded image do not follow the grooves 202a of the optical disc 200, the rotation direction of the optical disc 200 does not need to be different from that at the time of data recording. Therefore, in such a configuration, the arrangement of the dot data corresponding to the image data formed on the optical disc 200 is arranged corresponding to each intersection of the concentric circle of the optical disc 200 and the radiation from the center, as shown in FIG. I do. Here, in order to explain the intersection coordinates on the optical disc 200, the concentric circles are defined as 1 row, 2 rows, 3 rows,..., M (final) rows in order from the outer circumference to the inner circumference. When one radiation is used as a reference line, the other radiation is conveniently defined in the clockwise order as one column, two columns, three columns,..., N (last) column. Also in this modification, similarly to the above-described embodiment, the last m rows correspond to positions where the distance from the center of the optical disc 200 is about 42 mm.
When defined in this manner, the frame memory 158 stores dot data corresponding to an array of m rows and n columns, as shown in FIG.
[0086]
Then, when forming an image on the optical disc 200, the stepping motor 140 is rotated at a predetermined angular velocity counterclockwise as in the data recording. Further, similarly to the above-described embodiment, the optical pickup 100 may be moved from the outer periphery to the inner periphery to perform laser light irradiation corresponding to dot data of m rows and n columns. In such a configuration, since the servo circuit 138 does not perform tracking control, a signal of Tr = 0 may be always supplied to the tracking actuator 122.
[0087]
<Changing the gradation level>
In the above embodiment, it is assumed that the image data of the encryption key information is composed of dot data indicated by “0” or “1” in m rows and n columns, and its density is “0” (bright) or 1 ”. There were only two (dark) gradations. However, for example, the density is set to 8 gradations, and one pixel (pixel) is 3 bits, and 8 (= 2 ³ ) A gradation image may be formed. Specifically, among the 3-bit dot data, (000) indicates the brightest (lightest) density, and (001), (010), (011), (100), (101), (110), (110) 111) to indicate dark (dark) density. Then, the intensity of the laser light emitted from the laser diode 102 of the optical pickup 100 may be set in accordance with these eight gradation data.
With such a configuration, the image formed on the optical disc 200 has a much richer expressive power.
[0088]
<Perform data recording and image formation by CLV (Constant Linear Velocity) method>
In the above-described embodiment, the optical disk 200 is irradiated with the laser beam by the CAV method in which the optical disk 200 is rotated at a constant angular velocity to record data or form an image on the optical disk 200. However, a configuration may be adopted in which these processes are performed by a CLV (Constant linear Velocity) method of tracing the optical disc 200 at a constant linear velocity. In the CLV method, unlike the CAV method, there is no need to control to increase the recording level of the laser light as the irradiation position of the laser light moves to the outer peripheral side of the optical disc 200. As a result, the quality of the formed image does not deteriorate.
[0089]
<Using an optical disc with a heat-sensitive layer on the label surface>
As shown in FIG. 16, in addition to the above-described protective layer 201, recording layer 202, reflective layer 203, and protective layer 204, an optical disk 200 is further laminated with a heat-sensitive layer (color changing layer) 205 and a protective layer 206. In this case, the heat-sensitive layer 205 undergoes thermal discoloration when irradiated with laser light having a certain intensity or higher. When using the optical disc 200 having such a configuration, when recording information, the optical disc 200 is set so that the surface (recording surface) on the protective layer 201 side faces the optical pickup 100, and the laser beam is directed along the groove 202a. Then, the data is recorded on the optical disc 200 by irradiating according to the data to be recorded.
On the other hand, when an image is formed, the optical disc 200 is set so that the surface (label surface) on the protective layer 206 side faces the optical pickup 100, and the heat-sensitive layer 205 is formed according to the image data in the same manner as in the above-described image forming process. By irradiating a laser beam having a sufficient intensity to thermally discolor the image, an intended image is formed.
It is determined whether the recording surface or the label surface of the optical disc 200 is set so as to face the optical pickup 100 by determining whether ATP (Absolute Time In Pregroove) information is recorded. Good. As is well known, the ATP information is information previously recorded in the groove 202a on the recording surface of the optical disc 200. Therefore, if the ATP information is recorded, it can be determined that the recording surface is set facing the optical pickup 100, and if the ATP information is not recorded, the label surface faces the optical pickup 100. It can be determined that it is set.
With such a configuration, data is recorded on the recording surface, and an image of key information corresponding to the data is formed on the label surface. Therefore, as described above, the image can be formed without being affected by the data amount of the data recorded on the recording surface.
[0090]
<Prohibition of recording of encrypted data and image formation of encryption key information>
For example, the optical disk recording device 10 may be configured to form an image other than the encryption key information. In this case, the user can select either to record the encrypted data on the optical disc 200 and form an image of the encryption key information corresponding to the data, or to form an image other than the encryption key information. Is also good.
Further, for example, when a user logs in to the host computer 500, only when the user logs in with a user name having a predetermined authority, the recording process of the encrypted data and the image forming process of the encryption key information can be performed on the optical disc 200. If the user logs in with a user name other than the above, that is, if the user logs in with a user name that does not have the predetermined authority, these processes cannot be performed. When the user logs in to the host computer 500 with a user name having predetermined authority, and the encryption key information is input, the control unit 501 of the host computer 500 sets a signature for permitting image formation of the encryption key information. Assigned to encryption key information. When the user logs in to the host computer 500 with a user name that does not have a predetermined authority, and the encryption key information is input, the control unit 501 of the host computer 500 sets a signature that does not permit image formation of the encryption key information. Assigned to the encryption key information. When the encryption key information is transferred from the host computer 500, the optical disk recording device 10 refers to the signature corresponding to the encryption key information, and determines whether or not the optical disk recording device 10 has a signature that permits image formation of the encryption key information. An image of the encryption key information is formed. If the signature corresponding to the encryption key information is a signature that does not permit image formation of the encryption key information, the data recording and the image formation processing of the encryption key information are not performed.
[0091]
<Array of dots>
In the above-described embodiment, the number of columns is the same n from the first row to the last m rows. However, for example, the number of columns may be increased toward the outside. That is, the number of columns may be different for each row.
As described above, when the frequency multiplication factor in the PLL circuit 144 is set to the value of the quotient obtained by dividing the number n of columns per row by 8, one cycle of the clock signal Dck is generated on the optical disc 200 by one column of the dot array. This corresponds to a period rotated by an angle of minutes. Therefore, by setting the multiplication rate of the PLL circuit 144 for each row according to the number of columns, the number of columns is varied for each row.
[0092]
<About the image forming area>
In the present embodiment, the area where the distance from the center of the optical disc 200 is about 42 mm to 58 mm is used as the area for image formation. However, the area for image formation is variable depending on the capacity of data recorded on the optical disc. It is good. For example, based on the recording end address of the encrypted data recorded on the optical disc 200, the optical disc recording apparatus 10 may store data from an address several mm to several cm away from the recording end address with a margin not to destroy the data. An area up to the outermost periphery of the recordable area may be used as an image forming area. On the other hand, in the above-described encryption key image data generation processing, the host computer 500 may change the size of the generated image data according to the size of the image forming area.
[0093]
<Others>
In the above-described embodiment and its modifications, all processes performed by the control unit 501 of the host computer 500, such as encryption of data to be recorded on the optical disc 200 and decryption of the data, are performed by the optical disc recording device 10. The control may be performed by the main control unit 170. That is, it may be configured as an optical disk recording device incorporating the functions of the host computer 500.
[0094]
【The invention's effect】
As described above, according to the present invention, information can be recorded on an optical disc, and key information corresponding to the information can be formed visually.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an optical disc on which data recording and a visible image are formed by an optical disc recording apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of an optical disc recording device according to the embodiment.
FIG. 3 is a block diagram showing a configuration of an optical pickup in the optical disc recording device according to the embodiment.
FIG. 4 is a diagram for explaining the groove of the optical disc according to the embodiment as viewed from the recording surface.
FIG. 5 is a diagram for explaining dots of an image to be formed on the optical disc according to the embodiment.
FIG. 6 is a diagram for explaining storage contents of a frame memory according to the embodiment.
FIG. 7 is a timing chart for explaining detection of a reference line and detection of a dot row of the optical disc according to the embodiment.
FIG. 8 is a timing chart for explaining an operation of recording data and forming an image on the optical disc according to the embodiment.
FIG. 9 is a sequence chart for explaining an operation of forming an image on the optical disc according to the embodiment.
FIG. 10 is a sequence chart for explaining an operation of forming an image on the optical disc according to the embodiment.
FIG. 11 is a diagram showing an example of an image formed on the optical disc according to the embodiment.
FIG. 12 is a timing chart for explaining an operation of reproducing data recorded on the optical disc according to the embodiment.
FIG. 13 is a block diagram showing a configuration of a host computer according to the embodiment.
FIG. 14 is a diagram for explaining dots of an image to be formed on the optical disc according to the modification.
FIG. 15 is a diagram for explaining storage contents of a frame memory according to the modification.
FIG. 16 is a side sectional view showing a schematic configuration of an optical disc capable of forming a visible image by the optical disc recording device according to the modification.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Optical disk recording device, 100 ... Optical pickup, 102 ... Laser diode, 104 ... Diffraction grating, 108 ... Light receiving element, 110 ... Optical system, 111 ... Polarization beam splitter , 112: Collimator lens, 113: Wave plate, 114: Objective lens, 115: Cylindrical lens, 121: Focus actuator, 122: Tracking actuator, 130: Spindle motor, 132 rotation detector, 134 RF amplifier, 136 decoder, 138 servo circuit, 140 stepping motor, 142 motor driver, 144 PLL circuit, 146 ... frequency divider circuit, 150 ... interface, 152 ... buffer memory, 154 ··· Encoder, 156 ··· Strategy circuit, 158 ··· Frame memory, 162 ··· Laser power control circuit, 164 ··· Laser driver, 170 ··· Main control unit, 200 ··· Optical disk, 201 · ..Protective layer, 202 ... Recording layer, 202a ... Groove, 203 ... Reflective layer, 204 ... Protective layer, 205 ... Heat sensitive layer, 206 ... Protective layer, 500 ... Host computer, 501: control unit, 502: operation unit, 503: display unit, 504: interface, 505: ROM, 506: RAM, 507: bus.

Claims (6)

An optical disk write data processing device that supplies data to be written to an optical disk recording device that records data and forms an image by irradiating a laser beam to a discoloration layer of the optical disk,
Data generation means for generating write data by restricting data to be recorded so that reproduction is impossible without key information, and generating key image data by imaging the key information,
An output means for outputting the write data and the key image data and indicating a write position so that the write positions do not overlap with each other. 2. The optical disk write data processing device according to claim 1, wherein the key image data is character image data or bar code data. An optical disk recording means for recording data and forming an image by irradiating a laser beam to the discoloration layer of the optical disk;
Data generation means for generating write data by restricting data to be recorded so that reproduction is impossible without key information, and generating key image data by imaging the key information,
An optical disk recording apparatus, comprising: an output unit that outputs the write data and the key image data to the optical disk recording unit and indicates a writing position so that these writing positions do not overlap. When recording data or forming an image by irradiating a laser beam to a discoloration layer of an optical disc, a method of creating data to be written on the optical disc,
A data generating step of generating write data by applying a restriction such that data to be recorded cannot be reproduced without key information, and generating key image data by imaging the key information;
An output step of outputting the write data and the key image data, and designating a write position so that the write positions do not overlap. When recording data or forming an image by irradiating a laser beam to a discoloration layer of an optical disc, a program for creating data to be written to the optical disc includes:
On the computer,
A data generating step of generating write data by applying a restriction such that data to be recorded cannot be reproduced without key information, and generating key image data by imaging the key information;
An output step of outputting the write data and key image data and designating a write position so that the write positions do not overlap. A storage medium storing the program according to claim 5.

Images