JP2008034019A - Optical disk recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new mechanism by which a recordable data amount in an optical disk can be visually confirmed by a user. <P>SOLUTION: An image formed on a drawing layer is an image having a circular shape having the center of the optical disk 1 as a center. As shown in Figs.11(a) and (b), the size of the image (the region discolored by laser light) is a size according to a data recorded amount in a data recording layer. As being understood by comparison of Figs.11(a) and (b) with Figs.11(c) and (d), according as the recorded data amount is increased, the discolored region in the drawing layer is gradually and concentrically increased from the center of the optical disk 1 toward the outer edge of the disk. Thereby, the recordable data amount in the optical disk can be confirmed by the user. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for forming a data recording state on an optical disk.

For example, for a recordable optical disc such as a CD-R (Compact Disc-Recordable), a CD-RW (Compact Disc-Rewritable), or a DVD-R (Digital Versatile Disk-Recordable), a plurality of discs are required until the recording capacity is reached. Data can be added over time. In this case, it is convenient if there is a mechanism that allows the user to visually recognize the amount of data that can be recorded (hereinafter referred to as the remaining amount). This is because it is possible to confirm in advance whether or not the remaining amount of the optical disk exceeds the size of the data to be recorded before starting recording on the optical disk. Therefore, for example, Patent Document 1 proposes an optical disc in which a color tone changing material whose color tone is changed by heat is applied to the label surface of the optical disc. When such an optical disc is used, the color tone of the color tone changing material changes due to heat generated during data recording. Therefore, just by looking at the label surface, an area where data is recorded is distinguished from an area where no data is recorded. This means that the remaining amount of the optical disk can be roughly estimated.
JP 2001-6223 A

  The present invention has been made in view of the above-described background, and an object thereof is to provide a new mechanism by which a user can recognize the amount of data that can be recorded on an optical disc.

  In order to solve the above-described problems, the present invention relates to an optical disc having a data recording layer on which data is recorded and a discoloration layer provided at a position different from the data recording layer and discolored by heat or light. Irradiating means for irradiating a laser beam focused on either the data recording layer or the color changing layer from one surface of the recording medium; Data recording means for recording data on the data recording layer by irradiating together, recorded data amount that is the amount of data recorded on the data recording layer, or amount of data recordable on the data recording layer Specific means for specifying a recordable data amount, and laser light is focused on the drawing layer from the irradiation means, and the laser light is irradiated on the drawing layer. An optical disk recording apparatus comprising: a drawing unit that draws an image representing the recorded data amount or the recordable data amount specified by the specifying unit on the drawing layer by changing the color of the region formed I will provide a. According to the present invention, the user can recognize the amount of data that can be recorded on the optical disc.

  The drawing unit may draw an image in which the recorded data amount or the recordable data amount specified by the specifying unit is represented by characters. In this way, a more detailed recorded data amount or recordable data amount can be specified by looking at the characters.

  The drawing unit may draw an image in which the recorded data amount specified by the specifying unit is represented by a size of a region that has been changed in color by being irradiated with laser light in the drawing layer. Good. Accordingly, the recorded data amount or the recordable data amount can be roughly grasped by looking at the size of the discolored area. In this case, for example, the drawing unit specifies the recorded data specified by the specifying unit. As the amount of data increases, an image may be drawn such that the region of the drawing layer that has been discolored by being irradiated with laser light increases concentrically from the center of the optical disc toward the outer edge of the disc. In addition, as the amount of recorded data specified by the specifying unit increases, an area that is changed in color by being irradiated with laser light in the drawing layer spirals from the center of the optical disc toward the outer edge of the disc. It is possible to draw a long image or to irradiate the drawing layer with laser light. An image may be drawn in which the fan-shaped central angle formed along the outer edge of the optical disc by the color change increases as the recorded data amount specified by the specifying unit increases. .

  Further, the drawing means may be a region corresponding to a character representing the recorded data amount or the recordable data amount specified by the specifying means in an area where the laser beam is irradiated and changed in color in the drawing layer. On the other hand, by not irradiating the laser beam, an image representing the recorded data amount or the recordable data amount in characters may be drawn. In this way, the recorded data amount or recordable data amount can be roughly grasped by looking at the size of the discolored area, while the more detailed recorded data amount or recordable data amount is the character It becomes possible to specify if it sees.

  According to the present invention, a user can recognize the amount of data that can be recorded on an optical disc.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The optical disk recording apparatus according to the present embodiment allows a user to visually recognize, for example, a function for recording / reproducing data of music data (data recording / reproducing function) on an optical disk and a data amount that can be recorded on the optical disk. A function to draw a simple image (drawing function). This image represents at least one of the recorded data amount that is the amount of data recorded on the optical disc and the recordable data amount that is the amount of data that can be recorded on the optical disc. Even if the image represents the recorded data amount, if the user viewing the image knows the original recording capacity of the optical disc, the recorded data amount is subtracted from the recording capacity, It is possible to recognize the amount of data that can be recorded on the optical disc.
In the following description, the configuration of the optical disk will be described first, and then the optical disk recording apparatus will be described.

(1) Configuration of Optical Disc FIG. 1 is a cross-sectional view of three types of optical discs according to this embodiment, that is, DVD-R, CD-R, and CD-R / DVD-R mixed type optical disc. In the DVD-R 1a, in order from the recording surface Da to the label surface La, a polycarbonate layer 101a, a data recording layer 103a, a semitransparent layer 104a, an intermediate layer 105a, a drawing layer 106a, a semitransparent layer 107a, and a polycarbonate layer 108a Are stacked. The thickness of the DVD-R1a is approximately 1.2 (mm), of which the polycarbonate layer 101a and the polycarbonate layer 108a occupy about 0.6 (mm), respectively, from the data recording layer 103a to the semitransparent layer 107a. Is a minute distance Δd1.

  A spiral groove (guide groove) 102a is formed on the recording surface Da side of the data recording layer 103a. At the time of data recording, the position of the objective lens 33a is adjusted to an appropriate position in the direction of arrow P, and the laser beam is focused on the data recording layer 103a based on the reflected light from the semitransparent layer 104a. Then, a laser beam having an intensity corresponding to the data to be recorded is irradiated along the groove 102a of the data recording layer 103a. At this time, pits corresponding to the data length are formed at the locations irradiated with the laser beam, and data recording is thereby performed. In the case where the recorded data is read and reproduced, data reproduction is performed by irradiating the groove 102a with laser light having a weaker intensity than that during recording and detecting the intensity of the reflected light (return light). Realized.

  The drawing layer 106a is a color changing layer formed of a substance that changes color when irradiated with laser light having a certain intensity. At the time of drawing, the position of the objective lens 33a is adjusted to an appropriate position in the direction of arrow P, and the laser beam la is focused on the drawing layer 106a based on the reflected light from the semi-transparent layer 107a. When the laser beam la having a certain intensity is irradiated, the region of the drawing layer 106a irradiated with the laser beam la changes color. An image that can be visually recognized by the user is formed by the discolored area and the undiscolored area. FIG. 1 shows a case where the focused laser beam la is irradiated onto the drawing layer 106a.

Next, CD-R1b will be described.
In the CD-R 1b, in order from the recording surface Db to the label surface Lb, a polycarbonate layer 101b, a data recording layer 103b, a semitransparent layer 104b, an intermediate layer 105b, a drawing layer 106b, a semitransparent layer 107b, and a protective layer 108b Are stacked. A spiral groove 102b is formed on the recording surface Da side of the recording layer 103b. The drawing layer 106a has a property of changing color when irradiated with laser light having a certain intensity. Similar to DVD-R1a, the thickness of CD-R1b is approximately 1.2 (mm), most of which is the thickness of polycarbonate layer 101b, and the thickness from data recording layer 103b to protective layer 108b is very small. The distance Δd2.

  The principle for recording / reproducing data on the CD-R1b and for forming an image is the same as that for the DVD-R1a. That is, at the time of data recording, the data recording layer 103b is focused, and laser light having an intensity corresponding to the data to be recorded is irradiated along the groove 102b. At the time of drawing, the focused laser beam lb is irradiated on the drawing layer 106b, and the irradiated region changes color. An image that can be visually recognized by the user is formed by the discolored area and the undiscolored area. FIG. 1 shows a case where the focused laser beam lb is irradiated on the drawing layer 106b.

Next, CD-R / DVD-R1c will be described.
In the CD-R / DVD-R1c, the polycarbonate layer 101c, the data recording layer 103c, the semitransparent layer 104c, the intermediate layer 105c, the drawing layer 106c, the semitransparent layer 107c, and the recording surface Dc in this order from the recording surface Dc. A protective layer 108c is laminated. A spiral groove 102c is formed on the recording surface Dc side of the recording layer 103c. The drawing layer 106c has a property of changing color when irradiated with laser light having a certain intensity. Similar to DVD-R1c and CD-R1b, the thickness of CD-R / DVD-R1c is approximately 1.2 (mm), most of which is the thickness of polycarbonate layer 101c and intermediate layer 105c, and data recording The thickness from the layer 103c to the translucent layer 104c is a minute distance Δd3, and the thickness from the drawing layer 106c to the protective layer 108c is a minute distance Δd4.

  The principles for recording / reproducing data on the CD-R / DVD-R1c and for forming an image are the same as those for the DVD-R1a and CD-R1b. That is, at the time of data recording, the data recording layer 103c is focused and laser light having an intensity corresponding to the data to be recorded is irradiated along the groove 102c. At the time of drawing, the focused laser beam lc is irradiated onto the drawing layer 106c, and the irradiated region changes color. An image that can be visually recognized by the user is formed by the discolored area and the undiscolored area. FIG. 1 shows a case where the focused laser beam lc is irradiated onto the drawing layer 106c.

(2) System and Device Configuration As shown in FIG. 2, the system according to the present embodiment is configured by connecting the host device 10 and the optical disk recording device 12 in a state where they can communicate with each other. The optical disk recording device 12 may be in a format built in the host device 10 or an externally attached format. The optical disk recording device 12 is loaded with any of the above-described DVD-R1a, CD-R1b, and CD-R / DVD-R1c (hereinafter collectively referred to as the optical disk 1).

  In the optical disk recording device 12, the optical disk 1 is rotated by a spindle motor 30. The spindle servo 32 controls the rotation of the spindle motor 30 at a constant linear velocity during recording and reproduction (CLV control) and at a constant rotation speed during drawing (CAV control). The optical pickup 34 (optical head) is transferred in the radial direction of the optical disc 1 (left and right in the figure) by a feed mechanism 38 such as a feed screw driven by a stepping motor 36. The motor driver 40 drives the stepping motor 36 based on a command from the system control unit 56.

  The stepping motor 36 is constituted by, for example, a two-phase stepping motor of the type shown in FIG. The two-phase stepping motor 36 includes two coils 36a and 36b, and is bipolar driven by two-phase drive pulses applied from the drivers 40a and 40b constituting the motor driver 40 to the coils 36a and 36b. . FIG. 4 shows voltage waveforms of the drive / pulses A and B applied to the coils 36a and 36b when the two-phase stepping motor 36 is driven at full step. These drive pulses A and B are square wave signals whose duties are 50% and whose polarities are alternately switched and whose phases are shifted from each other by 90 °. By using these driving / pulses A and B, the rotor 37 rotates by 90 ° per step. By using the microstep driving method as the driving method of the stepping motor 36, the rotation angle per step can be reduced. FIG. 5 shows an example of voltage waveforms of the drive pulses A and B applied to the coils 36a and 36b when the two-phase stepping motor 36 is micro-step driven. FIG. 5 shows a waveform when the number of divisions per full step is “5”. By using this drive pulse, the rotor 37 is 1 / step of 1 step in full step drive per micro step. Rotate by 5 (= 18 °).

  In FIG. 2 again, the focus servo 42 performs focus control of the optical pickup 34 at the time of data recording and reproduction and at the time of drawing. The focus jump signal generator 43 generates a control signal instructing to focus the laser beam on the data recording layer of the optical disc 1 at the time of data recording and reproduction. A control signal is generated that instructs to focus. The tracking servo 44 performs tracking servo control of the optical pickup 34 during data recording and reproduction. However, the tracking servo control is turned off at the time of drawing.

  The vibration signal generator 46 generates a vibration signal at the time of drawing and supplies the vibration signal to the tracking actuator of the optical pickup 34 to vibrate the objective lens 33. As a result, the laser beam is vibrated in the radial direction of the optical disc 1 with an amplitude larger than the unit feed amount by the 1 micro-step operation of the optical pickup 34. By this vibration operation, the laser beam scans the drawing layer while meandering with a width wider than the unit feed amount of the optical pickup 34. Thereby, as described later, in combination with the overwriting operation at the same circumferential position, it is possible to perform drawing with a small gap. The laser driver 48 drives the laser diode of the optical pickup 34 at the time of data recording and reproduction and at the time of drawing. An ALPC (Automatic Laser Power Control) circuit 50 controls the laser power to a commanded value at the time of data recording and reproduction and at the time of drawing.

  The encoder 52 encodes the recording data into a format corresponding to the format (CD or DVD) of the optical disc 1 at the time of data recording. The laser driver 48 modulates the laser beam according to the encoded recording data, and records the recording data as pits on the data recording layer of the optical disc 1. On the other hand, at the time of drawing, the encoder 52 generates a pulse signal (drawing signal) whose duty changes according to the gradation data of the pixels constituting the image data. The laser driver 48 modulates the laser light according to the pulse signal whose duty changes, changes the visible light characteristic of the drawing layer 24 of the optical disc 1 (that is, changes the color), and performs drawing with monochrome multi-tone. The decoder 54 performs data reproduction by EFM demodulating a received light signal corresponding to the return light received by the optical pickup 34 during data reproduction.

  The host device 10 transmits recording data to the optical disk recording device 12. The recording data is received by the interface 58 of the optical disc recording apparatus 12 and once stored in the buffer memory 60, then read out and supplied to the encoder 52. At the time of data reproduction, the data reproduced by the decoder 54 is transferred to the host device 10 via the interface 58. In addition, the host device 10 transmits a command from the operator to the optical disc recording device 12 during data recording and reproduction and drawing. This command is transmitted to the system control unit 56 via the interface 58. The system control unit 56 sends a command corresponding to the command to each circuit in the optical disc recording apparatus 12 to execute the corresponding operation.

  The memory 62 in the optical disc recording device 12 stores drawing conditions preset in the optical disc recording device 12 and drawing conditions that can be set by the operator. As the “preliminarily set drawing conditions”, “feed amount N of optical pickup 34 by one full-step operation of stepping motor 36” used for calculation of unit feed amount for transporting optical pickup 34 in the radial direction of optical disc 1 is used. And “the division number M of the microstepping operation of the stepping motor 36” is stored. As “drawing conditions that can be set by the operator”, information on a plurality of types of “drawing modes” in which “rotation speed of the optical disk” and “encoding speed of image data by the encoder 52” are combined is stored. Yes.

Next, the configuration of the encoder 52 will be described with reference to FIG.
In FIG. 6, an encoder circuit 64 inputs recording data at the time of data recording and image data at the time of drawing. The encoder circuit 64 performs EFM modulation after interleaving the recorded data at the time of data recording, and further performs synchronization processing, parity data and margin bit addition processing, and NRZI (Non Return to Zero Invert) conversion processing to generate one EFM frame. Consecutive recording signals are created. The recording signal created by the encoder circuit 64 passes through the AND gate 68 as it is and is supplied to the laser driver 48. The laser driver 48 drives the laser diode 70 in accordance with the recording signal to modulate the laser light power into binary values, and records the recording signal as pits on the data recording layer of the optical disc 1. That is, the laser driver 48 increases the laser power to a level at which pits are formed when the recording signal is “H” level, and decreases the laser power to a level at which no pits are formed when the recording signal is “L” level.

  The encoder circuit 64 processes image data at the time of drawing in the same manner as recording data at the time of data recording. However, it is possible not to perform the interleaving process. When the interleaving process is not performed, the encoder circuit 64 performs EFM modulation of the image data as it is without performing the interleaving process, and further performs a synchronization process, a parity data and margin bit addition process, and an NRZI conversion process to obtain 1 EFM. Recording signals constituting a frame are continuously generated. Here, the data of one EFM frame includes image data for one pixel (gradation data representing the gradation of that pixel). In the present embodiment, one pixel data is represented by one EFM frame length.

  The decoder circuit 66 is switched between data recording and drawing. First, at the time of data recording, the decoder circuit 66 continuously outputs an “H” level signal. This “H” level signal is input to one input terminal of the AND gate 68. Accordingly, the output of the encoder circuit 64 input to the other input terminal of the AND gate 68 at the time of data recording, that is, the recording signal passes through the AND gate 68 as it is. On the other hand, at the time of drawing, the decoder circuit 66 performs EFM demodulation on the data output from the encoder circuit 64, and acquires gradation data of the pixel for each pixel per 1 EFM frame. Then, the decoder circuit 66 outputs a pulse signal DOTX whose cycle is 1 EFM frame length and whose duty changes according to the acquired gradation data for each image. This pulse signal DOTX is input to one input terminal of the AND gate 68. Therefore, at the time of drawing, the AND gate 68 opens the gate for a time corresponding to the gradation value of the corresponding pixel for each 1 EFM frame period, and outputs the output signal of the encoder circuit 64 input to the other input terminal ( NRZI converted EFM signal) is allowed to pass through for that time. The fragment signal WEN (drawing signal for drawing one pixel) of the NRZI signal output from the AND gate 68 is no longer meaningful, but the duty is about 50% because it is an NRZI signal. . Therefore, the duty for one EFM frame length of the NRZI fragment signal WEN passing through the AND gate 68 during one EFM frame period corresponding to one pixel (the pulse width of the NRZI fragment signal WEN passing through the AND gate 68 during that period for one EFM frame length) (The ratio of the total value) corresponds to the duty of the pulse signal DOTX, that is, corresponds to the gradation value of the corresponding pixel.

  The NRZI fragment signal WEN output from the AND gate 68 at the time of drawing is supplied to the laser driver 48 as a drawing signal. The laser driver 48 drives the laser diode 70 in accordance with the drawing signal WEN, modulates the power of the laser light into binary values, and irradiates the drawing layer of the optical disc 1. Specifically, the laser driver 48 increases the laser power to a level at which the drawing signal WEN is “H” level, and lowers the laser power to a level at which the drawing signal WEN is “L” level. In this case, since the circumferential distance on the optical disc 1 corresponding to 1 EFM frame length (that is, the circumferential length assigned to draw one pixel) is extremely short, one drawn pixel is a human figure. It will be a single point (dot) for the eyes. The higher the duty, the lighter the drawing. In this way, gradation can be expressed in the image formed on the drawing layer of the optical disc 1.

Here, setting of the duty of the pulse signal DOTX output from the decoder circuit 66 at the time of drawing will be described with reference to FIGS.
FIG. 7 shows the relationship between the data structure of the EFM frame and the pulse signal DOTX. The “bit string” in FIG. 7A represents the format of the NRZI signal, and the numbers in the figure are the number of bits. “Data structure” in FIG. 7B represents the data structure of the EFM frame. “EFM sync” is a sync pattern indicating an EFM frame delimiter, “D0” to “D23” is data, “P0” to “P3” are P parity, “Q0” to “Q3” are Q parity, and “m”. Is a margin bit. The data structure of the EFM frame itself is the same for data recording and drawing. What is different between data recording and drawing is the contents of the data D0 to D23. That is, the data recording data D0 to D23 is data representing information to be recorded, while the drawing data D0 to D23 is data corresponding to the gradation of one pixel assigned to the 1EFM frame.

  “DOTX” in FIG. 7C is a pulse signal DOTX. This pulse signal DOTX is divided into 24 segments of 1 EFM frame length into 0 to 23 and set to “H” level or “L” level in units of the divided segments (duty varies from 0 to 100%). Signal). As indicated by arrows in FIG. 7, the data D0 to D23 are associated with the sections 0 to 23 of the pulse signal DOTX, respectively. When the data D0 to D23 is a specific code, the corresponding divided section of the pulse signal DOTX is set to “H” level, and when the data D0 is other code, the corresponding divided section of the pulse signal DOTX is set to “L” level. Set to That is, according to the gradation data demodulated by the decoder circuit 66 (FIG. 6) (here, data I representing 25 gradations from the 0th gradation to the 24th gradation) ), All the divided sections of the pulse signal DOTX are set to “L” level. In the case of the first gradation, only one divided section of the pulse signal DOTX is set to “H” level, and in the case of the second gradation. The two divided sections of the pulse signal DOTX are set to the “H” level. In the case of the 24th gradation (most wasteful density), all the divided sections of the pulse signal DOTX are set to the “H” level.

  FIG. 8 shows an example of the waveform of the pulse signal DOTX for each of 25 gradation levels from the 0th gradation to the 24th gradation. In this setting, the “H” level section of the pulse signal DOTX gradually spreads from the vicinity of the center of the section of 1 EFM frame length to the front and rear sides as the number of gradations increases. The decoder circuit 66 sets the values of the data D0 to D23 so that the pulse signal DOTX shown in FIG. 8 is generated according to the demodulated gradation data. That is, among the data D0 to D23, the data corresponding to the divided section in which the pulse signal DOTX is set to the “H” level is set to the specific code, and the data corresponding to the divided section in which the pulse signal DOTX is set to the “L” level. The data to be set is set to a code other than the specific code. Further, FIG. 9 shows operation waveforms at the time of drawing by the encoder 52. In FIG. 9, the NRZI signal of (a) is switched by the AND gate 68 at a period of 1 EFM frame length by the pulse signal DOTX of (b), and the NRZI fragment signal WEN of (c) is created. Note that the NRZI signal and the WEN signal in FIG. 9 have simple waveforms for easy understanding.

(3) Operation Next, the operation of the system described above will be described.
FIG. 10 is a flowchart showing the operation of the system control unit 56. In FIG. 10, when an optical disk is inserted into the optical disk recording device 12 (step S1), the system controller 56 starts data recording on the data recording surface of the optical disk 1 (step S2). Specifically, the spindle servo 32 controls the spindle motor 30 at a constant linear velocity so that the wobble signal extracted from the light reception signal of the optical pickup 34 has a predetermined frequency. The focus servo 42 and tracking servo 44 are turned on. The vibration signal generator 46 stops generating the vibration signal. Based on the residual error of the tracking servo, the system control unit 56 drives the stepping motor 36 by a predetermined amount and sequentially moves the optical pickup 34 toward the outer periphery of the disk, so that the optical axis position of the objective lens 33 is always near the recording position of the optical disk 1. Control to be Recording data is transferred from the host device 10 to the optical disk recording device 12. The recorded data is once stored in the buffer memory 60 via the interface 58. This recording data is sequentially read out from the buffer memory 60 according to the progress of recording, and is subjected to EFM modulation after interleaving processing by the encoder 52, and further converted into an NRZI signal. The NRZI signal is supplied to the laser driver 48 via the ALPC circuit 50. The laser driver 48 modulates the laser light with the NRZI signal. The modulated laser light is emitted from the optical pickup 34 and irradiated onto the data recording layer of the optical disc 1 to record data.

  When the data has been recorded (step S3; Yes), the system control unit 56 determines whether to draw an image on the optical disc 1 (step S4). For example, when the user does not want to visually recognize the amount of data that can be recorded on the optical disc 1, it is preset in the optical disc recording apparatus 1 that image formation is not performed. It is determined that no image is drawn. On the other hand, when the user desires to visually recognize the amount of data that can be recorded on the optical disc, that fact is preset in the optical disc recording apparatus 1, and in this case, the system control unit 56 determines that an image is drawn (step). S4; Yes).

  The system control unit 56 first refers to the lead-in area of the optical disc 1 and specifies (acquires) the amount of data already recorded on the disc (step S5). Then, the system control unit 56 generates image data for drawing an image based on the specified (acquired) recorded data amount (step S6). At this time, the system control unit 56 generates original image data in an orthogonal coordinate system, and then generates drawing image data obtained by converting the coordinate system into a polar coordinate system. This image data is composed of, for example, a monochrome multi-gradation bitmap format, and is a set of data (gradation data) representing the gradation of each pixel constituting one image to be drawn on the optical disc 1. Composed. This image data is temporarily stored in the buffer memory 60. The image represented by this image data is an image representing the amount of recorded data or the amount of recordable data by the size of the area that has been changed in color by irradiating the drawing layer with laser light.

  Next, the system control unit 56 sends an instruction to the focus jump signal generator 43 to instruct the laser beam to be focused on the drawing layer of the optical disc 1. As a result, the focus of the laser beam jumps from the data recording layer to the drawing layer (step S7), and drawing is started (step S8). When drawing is started, the spindle servo 32 can output FG / pulses at a predetermined rotation angle from the spindle motor 30 (for example, 6 or 18 pulses per rotation are output at equal angular intervals). The spindle motor 30 is controlled at a constant rotational speed by PLL control so that the phase of the clock generated by dividing the crystal oscillation clock is synchronized with the phase. At this time, the focus servo 42 is turned on and the tracking servo 44 is turned off. The vibration signal generator 46 generates a vibration signal. The system control unit 56 detects the disk rotation, drives the stepping motor 36 by a predetermined amount at a certain rotation angle position at every rotation number designated as the number of overwriting, and sequentially transfers the optical pickup 34 in the disk outer circumferential direction. .

  The image data is sequentially read from the buffer memory 60 according to the progress of drawing, EFM-modulated by the encoder 52 (or EFM-modulated after the interleaving process), and then converted into an NRZI signal {FIG. 9 (a)}. Then, it is modulated into an NRZI fragment signal WEN {FIG. 9 (c)} having a duty corresponding to the gradation value of each pixel constituting the image data. The NRZI fragment signal WEN is supplied to the laser driver 48 via the ALPC circuit 50. The laser driver 48 modulates the drawing laser beam with the NRZI fragment signal WEN. The modulated drawing laser light is emitted from the optical pickup 34 and applied to the drawing layer of the optical disc 1. When the drawing is finished (step S9; Yes), the optical disc 1 is ejected out of the optical disc recording device 12 (step S10).

The above is the operation of data recording and drawing instruction. The operation of data reproduction is as follows.
First, the spindle servo 32 controls the spindle motor 30 at a constant linear velocity (CLV) so that the clock reproduced from the light reception signal of the optical pickup 34 has a predetermined frequency. The focus servo 42 and tracking servo 44 are turned on. The vibration signal generator 46 stops generating the vibration signal. Based on the residual error of the tracking servo, the system control unit 56 drives the stepping motor 36 by a predetermined amount and sequentially moves the optical pickup 34 in the outer circumferential direction of the disk, so that the optical axis position of the objective lens 33 is always near the reproduction position of the optical disk 1. Control to be The optical pickup 34 emits a reproduction laser beam and reads a signal recorded on the data recording layer of the optical disc 1. The signal read by the optical pickup 34 is EFM demodulated by the decoder 54, output from the optical disk recording device 12 via the interface 58, and transferred to the host device 10.

  Here, FIG. 11 is a diagram schematically showing a relationship between a data recording state when viewed from the recording surface of the optical disc 1 and a drawing state when viewed from the label surface of the optical disc 1. FIGS. 11A and 11B show the state when the first data recording and drawing are finished, and FIGS. 11C and 11D show the state when the second data recording and drawing are finished. Represents a state. As illustrated, the image formed on the drawing layer is a circular image centered on the center of the optical disc 1. As shown in FIGS. 11A and 11B, the size of the image (region discolored by the laser beam) is a size corresponding to the amount of data recorded in the data recording layer. Therefore, as can be seen from a comparison between FIGS. 11A and 11B and FIGS. 11C and 11D, as the amount of recorded data increases, the area discolored in the drawing layer is the center of the optical disc 1. Gradually increases concentrically toward the outer edge of the disk. At this time, the drawing area shown in FIG. 11B and the difference area between the drawing area shown in FIG. 11B and the image area shown in FIG. May be. Also, different patterns are formed in the drawing area shown in FIG. 11B and the difference area between the drawing area shown in FIG. 11B and the image area shown in FIG. May be. In this way, when the user views the optical disc 1 from the label surface, the size of the data recorded at the time of recording each data can be roughly grasped. Further, for example, by forming an image having a beautiful pattern or interesting in the drawing layer, the user can be interested (the same applies to FIGS. 12 to 14 below).

  In the next example of FIG. 12, the image formed on the drawing layer is a fan-shaped image formed along the outer edge of the optical disk of the optical disk 1. FIGS. 12A and 12B show the state when the first data recording and drawing are finished, and FIGS. 12C and 12D show the second data recording and drawing finished. 12 (e) and 12 (f) show the state when the third data recording and drawing are finished. As shown in these figures, the size of the image (the region discolored by the laser beam) is a size corresponding to the amount of data recorded in the data recording layer. Therefore, as can be seen from a comparison between FIGS. 12A and 12B, FIGS. 12C and 12D, and FIGS. 12E and 12F, as the amount of recorded data increases, The central angle of the sector drawn in the drawing layer gradually increases.

  In the following example of FIG. 13 as well, the image formed on the drawing layer is a fan-shaped image formed along the outer edge of the optical disk of the optical disk 1, but differs from FIG. 12 in the size of the fan-shaped radial direction. Is larger in accordance with the amount of recorded data. FIGS. 13A and 13B show the state when the first data recording and drawing are finished, and FIGS. 13C, 13D, 13E, and 13F show the second data. FIG. 13G and FIG. 13H show the state when the third data recording and drawing are finished. FIGS. 13D, 13E, and 13F show variations in the drawing state when the second drawing is finished. For example, as shown in FIG. 13F, an image in which the recorded data amount or the recordable data amount (recordable data amount in the figure) is represented by characters may be drawn in white. This white image can be formed by not irradiating the region corresponding to the character with the laser beam in the region where the laser beam is irradiated and changed in color in the drawing layer. By expressing the characters in this way, the user can recognize the recorded data amount or the recordable data amount more accurately. If data cannot be recorded, an image representing the characters “Finalized” may be drawn in white as shown in FIG. In this way, the user can surely know that no more data can be recorded. In FIG. 13, there are “image added region” filled with black and “image added region” filled with diagonal lines. This is a region in which an image has already been drawn and a new image added. This is only for easy distinction between regions, and does not necessarily mean that the regions are images of different patterns and densities (the same in FIG. 14).

  The next example of FIG. 14 shows the amount of recordable data when the discolored area in the drawing layer gradually increases from the center of the optical disc 1 toward the outer edge of the disc as the recorded data amount increases. This is an image in which characters are represented in white. 14A and 14B show the state when the first data recording and drawing are completed, and FIGS. 14C and 14D show the second data recording and drawing completed. 14 (f) and 14 (g) show the state when the third data recording and drawing are finished. In this case, by adding an image as shown in FIG. 14E to the image shown in FIG. 14B, an image as shown in FIG. 14D is finally formed. become.

Next, details of a method for creating image data by the system control unit 56 will be described.
FIG. 15 shows the relationship between the coordinate positions of the original image data and the drawing image data. In FIG. 15, an area indicated by a white ring indicates an area that can be drawn on the optical disc 1. Here, the coordinate position of each surface element constituting the original image data is an orthogonal coordinate (where the position of the lowest end of the original image is the origin in the y-axis direction and the leftmost group of the original image is the origin position in the x-axis direction ( x, y) respectively. If the maximum value in the x-axis direction of the coordinates of the original image is X and the maximum value in the y-axis direction is Y, the coordinates of the center position of the original image (corresponding to the rotation center position of the optical disc 1) are (X / 2, Y / 2)
It is represented by

On the other hand, since drawing is performed by sequentially transporting the optical pickup 34 in the radial direction of the disk while rotating the optical disc 1, the drawing image data used for drawing is conveniently expressed in polar coordinates with the rotation center position of the optical disc 1 as a pole. It is. Therefore, here, the coordinate position of each pixel constituting the image data for drawing is set to the center position (X / 2, Y / 2) of the original image on the orthogonal coordinates as a pole, and the direction parallel to the x-axis direction of the orthogonal coordinates is the original. It is represented by a polar coordinate (r, θ) in which the radius is θ and the deviation angle θ increases counterclockwise from the original line. According to this, the arbitrary polar coordinate position (r, θ) of the drawing image data is the orthogonal coordinate position of the original image data (X / 2 + rcosθ, Y / 2 + rsinθ).
It will fall under.

FIG. 16 is a diagram showing a procedure for creating drawing image data based on original image data. Here, parameters other than those described above are defined as follows.
“RO”: writing start radius of the drawing area of the optical disc 1, that is, the innermost radius position of the drawing area (see FIGS. 11 to 14).
“Rl”: Write end radius of the drawing area of the optical disc 1, that is, the outermost radius position of the drawing area (see FIGS. 11 to 14).
“Δr”: a unit moving star of the optical pickup 34 in the disk radial direction, that is, an amount of movement of the optical pickup 34 by one microstep of the stepping motor 36. The value of Δr is based on the information of “feed amount N of optical pickup 34 in the disk radial direction by one full-step operation of stepping motor 36” and “division number M of micro-step operation of stepping motor 36”. , N / M calculation.
“Δθ”: deviation angle difference between pixels drawn adjacent to each other in the circumferential direction. The value of this declination difference Δθ is obtained by calculating Δθ = 2π / 1 the number of drawing per rotation based on the number of drawing per one rotation of the disk.
・ "L": Number of overwriting at the same radial position (integer)

FIG. 16 will be described. First, the system control unit 56 sets the next position (x, y) on the orthogonal coordinates for the writing start position (r = RO · θ = 0) in the drawing area of the optical disc 1 (step S21). ) And (2) (Step S22).
x = X / 2 + rcosθ (1)
y = Y / 2 + rsin∂ ... (2)
Next, the system control unit 56 extracts pixel data (gradation data) at the obtained position (x, y) from the original image data in which the position of each pixel is represented by orthogonal coordinates (step S23). . In addition, when x and y calculated by the formulas (1) and (2) have a fractional part, the decimal part is rounded off or rounded off, etc. Extract pixel data.

  Subsequently, the system control unit 56 performs pixel positions (r = RO, θ = Δθ), (r = RO, θ = 2Δθ), (r = RO, θ = 3Δθ),... In the same manner, the corresponding position (x, y) on the orthogonal seat is sequentially obtained from the equations (1) and (2), and these are obtained from the original image data. The image data at each position (x, y) is sequentially extracted (step S24). When this operation is performed for the number of times specified by the number L of overwriting (that is, when θ = 2π × L is reached), the generation of drawing image data for the number of times of overwriting is completed at the writing start radius position RO. (Step S25).

  Subsequently, the system control unit 56 returns the value of θ to 0 (step S26), and similarly for the next radial position r = RO + Δr, every Δθ from θ = 0 to θ = 2π × L. In addition, the pixel data constituting the drawing image data is sequentially extracted from the original image data. Then, this operation is repeated while increasing the radial position by Δr (step S27), and when the writing end radial position Rl is reached (step S28), the drawing image data for the entire drawing area is acquired from the original image data. Therefore, the creation of the drawing image data is terminated (step S29). In this way, drawing image data converted to polar coordinates is created from the original image data represented by orthogonal coordinates.

Next, the details of the drawing method by the system control unit 56 will be described.
In FIG. 17, the system control unit 56 positions the optical axis position in the disk radial direction of the objective lens of the optical pickup 34 at the writing start radial position RO before starting drawing (step S41). For this control, the stepping motor 36 is driven to temporarily return the optical pickup 34 in the inner circumferential direction, and the innermost origin position (a position detected by a limit switch or a position mechanically locked by a stopper) is set. Once detected, this is realized by driving the stepping motor 34 for the number of steps at which the objective lens starts writing from that position and reaches the radial position RO. Subsequently, a vibration signal is generated from the vibration signal generator 46 and supplied to the tracking actuator of the optical pickup 34, and the objective lens 33 is vibrated at a constant period in the disk radial direction (step S42). By setting the vibration frequency Hz to a value larger than the spindle rotation speed rps, vibration is performed for one cycle or more per spindle rotation. This vibration is continued until drawing is completed. Note that the tracking servo is turned off during drawing.

  When the objective lens is vibrated by the vibration signal, the “vibration frequency Hz” and the “spindle rotation speed rps” are set so that the value of “vibration frequency Hz / spindle rotation speed rps” becomes a circulation fraction with a long circulation digit number. It is desirable to set a value. In other words, with such a setting, even when the number of overwriting is large, the scanning positions of the laser beams can be prevented from overlapping each other during overwriting. For example, if the vibration frequency is set to 200 Hz with respect to the spindle rotation speed 131.25 rps, the value of “vibration frequency / spindle rotation speed rps” becomes a circulation decimal with a long circulation digit number.

  When the spindle motor 30 is stably CAV controlled at a predetermined rotational speed and the optical axis position in the disk radial direction of the objective lens 33 of the optical pickup 34 reaches the state where the writing starts and is positioned at the radial position RO, an arbitrary circumferential direction is reached. Drawing starts from the standpoint. The circumferential position where the drawing is started is determined as θ = 0 (step S43). During drawing, the clock generated by dividing the same crystal oscillation clock used for the CAV control of the spindle motor 30 is counted, and the circumferential position with respect to the position of θ = 0 is set to the Δθ (circumferential direction). Is detected for each pixel difference drawn between adjacent pixels. When θ = 2π × L is reached (step S44), it is determined that the circuit has made the number of turns designated by the number L of overwriting, and the stepping motor 36 is driven by 1 microstep so that the light from the objective lens 33 is emitted. The shaft position (center position of vibration) is moved by the distance Δr in the disk outer periphery direction (step S45). When θ = 2π × L, the count value of θ returns to 0 (step S46), and the count of θ is repeated as it is. The movement of the distance Δr is performed every time θ reaches 2π × L, and when the disk radial direction position reaches the writing end radial position Rl (step S47), the control is terminated (step S48).

  In addition, instead of setting the arbitrary circumferential position at which drawing is started as described above to θ = 0, a specific recognition code is formed on the inner peripheral side of the drawing area of the optical disc 1, and light is emitted prior to drawing. It is also possible to detect the circumferential position of this recognition code with the pickup 34, determine that position as θ = 0, and start drawing from this circumferential position. In this way, even when the optical disk 1 is inserted into or removed from the optical disk recording device 12, the position of θ = 0 does not change, so that drawing can be rewritten.

  The encoder 52 uses a clock generated by dividing the same crystal oscillation clock used for CAV control of the spindle motor 30 and detection of the optical axis position of the objective lens 33 of the optical pickup 34 in the disk radial direction. The image data for drawing is sequentially encoded at the encoding speed {encoding clock frequency (= 4.3218M pit) × encoding speed magnification} according to the drawing mode, and the duty changes according to the gradation data constituting the pixel data. The drawing signal (NRZI fragment signal WEN) to be generated is sequentially generated. Drawing is realized by driving the laser diode 70 of the optical pickup 34 with the drawing signal (NRZI fragment signal WEN in FIG. 9) sequentially encoded in this way, and modulating the laser light. That is, when the disk circumferential direction position where drawing is started is θ = 0, the optical axis position (vibration center position) of the objective lens 33 of the optical pickup is at an arbitrary position (r, θ) on the optical disk 1. The optical axis positions (in the disk circumferential direction and the disk radial direction) of the objective lens 33 so that drawing is performed with the laser light modulated by the NRZI fragment signal WEN generated based on the pixel data at the corresponding position (r, θ). The center position of vibration) and the encoding operation of the encoder 52 are synchronized. Since the CAV control of the spindle motor 30 and the encoding process by the encoder 52 are performed based on the same crystal oscillation clock, this synchronization is easily realized.

FIG. 18 shows an example of the locus of the scanning position of the drawing laser beam at one radial position when the number of overwriting is set to “3”. In FIG. 18, the circumference of the optical disc 1 is shown in a straight line for convenience of explanation. In the example of FIG. 18, the parameters are set as follows.
The feed amount of the optical pickup 34 in the disk radial direction by one full step operation of the stepping motor 36 = 95 μm
-Division number M of micro step operation of stepping motor 36 = 8
The amount of movement of the optical pickup 34 by one microstep of the stepping motor 36 Δr = N / M = 95 μm / 8
・ Vibration amplitude of laser light = 50 μm soil relative to the center position of vibration
・ Laser beam frequency Hz / spindle speed rps> l (circulation decimal)

  According to FIG. 18, the laser beam scans the disk radial direction range wider than the movement amount Δr of the optical pickup 34 by one micro step by the vibration operation. In addition, since the laser beam frequency Hz / spindle rotation speed rps is set to be a decimal fraction, the laser beam trajectories do not overlap each other. Therefore, even if each drawing line by the laser beam is thin, drawing with a small gap is realized.

  According to the embodiment described above, the recorded data amount that is the amount of data recorded in the data recording layer of the optical disc or the recordable data amount that is the amount of data recordable in the data recording layer is specified, and the laser By drawing light onto the drawing layer in focus and changing the area of the drawing layer irradiated with laser light, the image representing the specified recorded data amount or recordable data amount is drawn on the drawing layer. . Therefore, the user can recognize the amount of data that can be recorded on the optical disc. In addition, by controlling the gradation of the image, the user can change the density and pattern of the image drawn on the drawing layer according to the number of data recordings. Can be roughly understood, or the user can be interested and interesting. Also, if the finalizing process is performed on the optical disc and data cannot be recorded, an image representing the characters “Finalized” is drawn, so that the user can be sure that no more data can be recorded. I can know.

The embodiment described above may be modified as follows.
In the above-described embodiment, when the image is drawn on the optical disc 1, the optical disc recording device 12 generates image data. However, the host device 10 may generate this and supply it to the optical disc recording device 12. Good.

  Further, every time image formation is performed, time stamp information related to the date and time at the time of data recording may be formed as an image. The time stamp information may be supplied from the host device 10 to the optical disc recording device 12 as needed. Alternatively, a user name may be registered in advance and automatically formed as an image indicating the user name. The user name is registered by operating the host device 10 by the user. Then, it may be automatically formed every time data is recorded, or may be automatically formed when the data recording is finalized.

  The optical disc 1 is provided by each manufacturer, but it is conceivable that the characteristics of the data recording layer and the drawing layer are different for each manufacturer. For example, when the heat absorption rate of the data recording layer is different, it is assumed that the level of laser light to be irradiated for forming pits and the level of laser light to be irradiated for discoloration are different. The same applies to the drawing layer. For this reason, data recording and drawing are actually performed on the optical discs 1 of a number of manufacturers in advance to determine how much laser light is suitable for irradiation, and such values are stored in the memory 62. You may make it leave. In this case, if the identification information (disc ID information) indicating the type of the optical disc 1 is stored in association with it, the disc ID information of the set optical disc 1 is read, and then laser light irradiation according to the disc type is performed. can do.

  The drawing layer of the optical disk may be a color changing layer that changes color in response to at least one of heat and light. In addition, the position of the drawing layer on the optical disc 1 is not limited to that shown in FIG. 1, and in short, as long as it is provided at a position different from the data recording layer (the distance from the recording surface or label surface of the optical disc 1 is different). Good.

  The shape of the image formed on the drawing layer is not limited to that shown in the embodiment. For example, as the amount of recorded data increases, the image may be an image in which the region that is changed in color by being irradiated with laser light in the drawing layer becomes longer spirally from the center of the optical disc toward the outer edge of the disc. . In the embodiment, the image is expressed with multiple gradations. However, gradations are not always necessary, and a binary image indicating whether an image is formed or not may be used.

  In the above embodiment, “the division number M of the microstepping operation of the stepping motor 36” is fixed as “the preset drawing condition”, but this division number M can be set by the “operator” instead. It is good also as "a drawing condition". As a result, the optical disk recording device 12 changes the waveform of the driving / pulses A and B (FIG. 5) for microstep driving to the number of stages corresponding to the set division number M at the time of drawing. The drawing is performed by sequentially moving in the radial direction by the microstep movement amount. In this case, drawing image data obtained by extracting pixel data at radial positions for each microstep movement amount corresponding to the division number M set (selected) by the operator from the original image data is used.

It is sectional drawing of the optical disk which concerns on embodiment of this invention. It is a figure which shows the structure of the whole system which concerns on this embodiment. It is a schematic diagram which shows the structural example of a stepping motor. It is a voltage waveform diagram of a drive pulse when the stepping motor is driven at full step. It is a voltage waveform diagram of a drive pulse when the stepping motor is microstep driven. It is a block diagram which shows the structure of an encoder. It is a figure which shows the data structure of an EFM frame, and the relationship of the pulse signal DOTX. It is a figure which shows-example of the waveform for every gradation of pulse signal DOTX. It is an operation | movement waveform diagram at the time of drawing of an encoder. It is a flowchart which shows the process performed by a system control part. It is the figure which represented typically the data recording condition when it sees from the recording surface of an optical disk, and the drawing condition when it sees from the label surface of an optical disk. It is the figure which represented typically the data recording condition when it sees from the recording surface of an optical disk, and the drawing condition when it sees from the label surface of an optical disk. It is the figure which represented typically the data recording condition when it sees from the recording surface of an optical disk, and the drawing condition when it sees from the label surface of an optical disk. It is the figure which represented typically the data recording condition when it sees from the recording surface of an optical disk, and the drawing condition when it sees from the label surface of an optical disk. It is a figure which shows the relationship between the coordinate position of original image data and drawing image data. It is a flowchart which shows the process in which a system control part produces the image data for drawing based on original image data. It is a flowchart which shows the process which a system control part performs drawing. It is a figure which shows an example of the locus | trajectory of the scanning position of the drawing laser beam in one radial direction position at the time of setting the frequency | count of overwriting to "3".

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Host device, 12 ... Optical disk recording device, 34 ... Optical pick-up (irradiation means), 56 ... System control part (Identification means, Data recording means, Drawing means)

Claims (7)

For an optical disc having a data recording layer on which data is recorded and a discoloration layer provided at a position different from the data recording layer and discolored by heat or light, the data recording layer or the Irradiating means for irradiating laser light focused on any of the discoloration layers;
Data recording means for recording data on the data recording layer by irradiating the data recording layer with a focus on the data recording layer with laser light according to data; and
A specifying means for specifying a recorded data amount that is an amount of data recorded in the data recording layer or a recordable data amount that is an amount of data recordable in the data recording layer;
The recorded data amount specified by the specifying means or the recording is obtained by irradiating the drawing layer with the laser beam focused on the drawing layer and changing the color of the drawing layer irradiated with the laser light. An optical disk recording apparatus comprising: drawing means for drawing an image representing a possible data amount on the drawing layer. The optical disc recording apparatus according to claim 1, wherein the drawing unit draws an image in which the recorded data amount or the recordable data amount specified by the specifying unit is represented by characters. The drawing means draws an image in which the recorded data amount specified by the specifying means is expressed by the size of a region that has been changed in color by being irradiated with laser light in the drawing layer. Item 5. An optical disk recording apparatus according to Item 1. As the recorded data amount specified by the specifying means increases, the drawing means has a region that is changed in color by being irradiated with laser light in the drawing layer in a concentric manner from the center of the optical disc. The optical disk recording apparatus according to claim 3, wherein an image that becomes larger toward is drawn. The drawing means increases the amount of recorded data specified by the specifying means when the center angle of the sector formed along the outer edge of the optical disc increases when the drawing layer is irradiated with laser light to change the color. The optical disk recording apparatus according to claim 3, wherein an image that becomes larger as the image is drawn is drawn. As the recorded data amount specified by the specifying unit increases, the drawing unit changes the area of the drawing layer that has been changed by being irradiated with laser light from the center of the optical disc toward the outer edge of the disc. The optical disk recording apparatus according to claim 3, wherein an image that is spirally long is drawn. The drawing means is a region corresponding to a character representing the recorded data amount or the recordable data amount specified by the specifying means in an area where the laser beam is irradiated and changed in color in the drawing layer. 4. The optical disk recording apparatus according to claim 3, wherein an image representing the recorded data amount or the recordable data amount is drawn by not irradiating the laser beam.

Images