JP4230784B2 - Optical disc recording / reproducing apparatus and optical disc drawing system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  This invention, Les-Optical disc capable of forming images on the bell surfaceToThe present invention relates to an optical disk recording / reproducing apparatus for forming an image, and an optical disk drawing system including the optical disk and the optical disk recording / reproducing apparatus.
[0002]
[Prior art]
Examples of the recordable optical disc not stored in the cartridge include CD-R, CD-RW, DVD-R, DVD-RW, DVD + R, and DVD + RW.
[0003]
Conventionally, in order to manage a plurality of optical disks owned by the user, the management number may be manually recorded on each optical disk. However, when the user writes characters on the optical disc by hand, the appearance often deteriorates. In addition, if the user strongly writes characters on the label surface of the optical disk with a hard pen-tip writing instrument such as a ballpoint pen, the recording layer of the optical disk D may be damaged, and the recorded data may not be reproduced.
[0004]
In order to solve such problems, a printer has been developed that allows a user to print information such as a management number on the label surface of an optical disk (see, for example, Patent Document 1).
[0005]
Conventionally, a printing jig that can perform screen printing on the label surface side has been developed so that a manufacturer or a user of the above recordable optical disk can display specific information or information such as a management number. (For example, refer to Patent Document 2).
[0006]
By using a printer as described in Patent Document 1 or a printing jig as described in Patent Document 2, a user or a manufacturer can display images such as characters and pictures that look good on the label surface of the optical disk. Can be formed.
[0007]
However, in order to print an image on the label surface of the optical disc, the user has to purchase a printer and a printing jig separately, which has a problem that the cost burden is high for the user. In addition, there has been a problem that the user has to perform a complicated operation of taking out the optical disk from the optical disk apparatus and setting it on the printer after recording data on the optical disk with the optical disk apparatus.
[0008]
On the other hand, as shown in FIG. 5 of Patent Document 1, in the case of an optical disc drive with a print function, it is not necessary to purchase a printer separately, and it is not necessary to perform the above complicated work. Thus, accurate printing can be performed according to the surface treatment of the label surface. However, since the optical disk drive and the printer are integrated, the size of the apparatus becomes large and it is difficult to use it as a built-in drive of a computer. In addition, there is a problem that the price is expensive due to the complicated configuration, and the cost burden is also increased for the user.
[0009]
Screen printing is suitable for printing fixed contents such as user signatures and production lot numbers, but is not suitable for printing different contents such as serial numbers for production management for each optical disc. There was a problem. Further, since screen printing is not suitable for drawing an image finely, it cannot draw a bar code or the like in detail.
[0010]
Therefore, conventionally, there is an optical disc that can form an image on the label surface of the optical disc by using laser light irradiated to record data on the recording surface of the optical disc, and an optical disc recording apparatus that forms an image on the label surface of the optical disc. (For example, refer to Patent Document 3).
[0011]
[Patent Document 1]
JP 2002-298545 A (page 3-6, FIG. 1-7)
[Patent Document 2]
Japanese Patent Laid-Open No. 6-187671 (page 2, FIG. 1-5)
[Patent Document 3]
Japanese Patent Laid-Open No. 2002-203321 (page 5-10, FIG. 1-19)
[0012]
[Problems to be solved by the invention]
In the optical disc apparatus described in Patent Document 3, since an image can be formed by irradiating a laser beam onto the label surface of the optical disc, it is not necessary to provide another means for image formation in the optical disc apparatus, and the configuration is not complicated. There is no cost increase.
[0013]
In the optical disc described in Patent Document 3, for example, a leuco dye that is a color former that develops color when exposed to the heat of a laser beam and a developer are used in the visible light characteristic change layer. Leuco dyes and color developers are inexpensive and easily available, and are also used for thermal paper, for example.
[0014]
However, the leuco dye and the developer are easily separated when a long period of time elapses after color development or when the surrounding environment is bad or changes such as high temperature and high humidity. For this reason, some images are not so good in image storage stability. In other words, the color developed by the leuco dye and the developer gradually faded and eventually the color disappeared. As described above, when an image such as a character or a picture formed on the label surface side of the optical disk becomes thin, it becomes difficult to confirm the image.
[0015]
When the color developed by the leuco dye and the developer becomes thin, it can be developed again when irradiated with laser light and heated. However, in order to return the image formed on the label surface side of the optical disk to the original color, it is necessary to read the drawn image and accurately draw the image at the same position as the original image. An optical disc recording apparatus capable of drawing an image on a label surface has not been configured to execute such a thing. In addition, an optical disc that can draw an image on a label surface is not configured to be redrawn.
[0016]
  So, even if the image formed on the label surface becomes thin due to the passage of time or the surrounding environment, the present inventionOn optical discCan be redrawnLightdiskRecording / playbackAn object is to provide an apparatus and an optical disc drawing system.
[0017]
[Means for Solving the Problems]
The present invention has the following configuration as means for solving the above problems.
[0022]
  (1) A reflectance changing layer in which the reflectance of light in a specific wavelength band that does not include wavelength λ1 but includes wavelength λ2 is changed between the protective layer and the reflective layer by irradiation with laser light having wavelength λ1 from the label surface side. Prepared forLabel side of optical discIrradiate laser light from the sideOf the imagereadingAnd imageRewriteAn optical disc recording / reproducing apparatus for performing
  A first laser beam irradiation means for irradiating a laser beam having a wavelength λ1 to the label surface side of the optical disc;
  A second laser beam irradiation means for irradiating a laser beam having a wavelength λ2 to the label surface side of the optical disc;
  in frontOptical disc label surface~ sideWhen reading the image of,In the second laser light irradiation meansRead power from the label side of the optical discIrradiate laser lightAnd irradiating the first laser beam irradiating means with a laser beam having a read power from the label surface side of the optical disc,
  When rewriting an image on the label surface side of the optical disc, the first laser beam irradiation means is irradiated with a laser beam having a write power.Control means,
  It is provided with.
[0023]
  In this configuration, the optical disc recording / reproducing apparatus isProvided between the protective layer and the reflective layer is a reflectivity changing layer in which the reflectivity of light in a specific wavelength band not including the wavelength λ1 but including the wavelength λ2 is changed by irradiation with laser light having the wavelength λ1 from the label surface side.Image writing is performed by irradiating an optical disc with laser light having a write power of wavelength λ1.NoRead the image by irradiating the laser beam with the read power of wavelength λ2.Yeah. Therefore, by irradiating the label surface of the optical disc having the above characteristics with laser light having a write power of wavelength λ1, the reflectance of light in a specific wavelength band not including wavelength λ1 but including wavelength λ2 changes. Images can be recorded. Further, by irradiating the laser beam with the read power of the wavelength λ2, it is possible to detect the change in the reflectivity of the reflectivity change layer, so that the image recorded in this layer can be read and redrawn.
  (2) When the image on the label surface side of the optical disk is read, the control means irradiates the first laser light irradiation means with a laser beam of read power, performs tracking servo and focus servo, The second laser beam irradiation means is irradiated with a laser beam having a read power, and a change in reflectance is detected.
  In this configuration, the focus servo and the tracking servo can be stably performed by irradiating the laser light having the read power of the wavelength λ1 that does not change the reflectivity of the reflectivity changing layer of the optical disc. In addition, by irradiating laser light having a wavelength λ2 that changes the reflectivity of the reflectivity changing layer of the optical disc, it is possible to detect the change in reflectivity and reliably read the image drawn on the label surface of the optical disc. .
[0024]
  (3)The first laser beam irradiating means irradiates the optical disk according to claim 2 with a laser beam having a wavelength λ1 at a position where the second laser beam irradiating unit irradiates a laser beam having a wavelength λ2. Features.
[0025]
  Use with optical disc recording and playback deviceWhen an image has already been drawn on the label surface of the optical disk, when the laser beam with the read power of wavelength λ2 is irradiated, the reflectivity of the laser beam is reduced, and the focus servo and tracking servo may not be performed well. is there. In the present invention, a laser beam having a read power of wavelength λ1 that does not change the reflectivity of the optical disk can be irradiated to a position irradiated with the laser light of wavelength λ2, so that an image drawn on the label surface of the optical disk is pre-grooved. Along with the focus servo and tracking servo. Therefore, when the color of the image formed on the label surface of the optical disc becomes lighter due to the passage of time or environmental change, it can be easily redrawn.
[0026]
  (4)Bar code conversion means for converting arbitrary information into a barcode and irradiating the writing means with laser light having a wavelength λ1 in a barcode drawing pattern is provided.
[0027]
  In this configuration, it is possible to draw a barcode on the label surface of the optical disc used in the optical disc recording / reproducing apparatus.
  (5) A reflectance changing layer in which the reflectance of light in a specific wavelength band not including wavelength λ1 but including wavelength λ2 is changed by irradiation with laser light having wavelength λ1 from the label surface side is provided between the protective layer and the reflecting layer. An optical disc for
  A first laser beam irradiating means for irradiating a laser beam having a wavelength λ1 to the label surface side of the optical disc; a second laser beam irradiating device for irradiating a laser beam having a wavelength λ2 to the label surface side of the optical disc; When reading the image on the label surface side, the second laser beam irradiating unit is irradiated with a laser beam having a read power from the label surface side of the optical disc, and the first laser beam irradiating unit is irradiated with the first laser beam irradiating unit. When irradiating a laser beam of read power from the label surface side and re-writing an image on the label surface side of the optical disc, the first laser beam irradiation means is connected to the label surface side of the optical disc.La laAn optical disc recording / reproducing apparatus comprising:
It is characterized by comprising.
  In this configuration, the same effect as (1) can be obtained.The
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Details of the present invention will be described below. First, an optical disc according to an embodiment of the present invention will be described. In the following description, a CD-R which is a kind of recordable optical disc will be described as an example. FIG. 1 is a cross-sectional view showing the configuration of the optical disc D. FIG. 1A shows the area configuration of the optical disk D in the radial direction. FIG. 1B and FIG. 1C show the region configuration of the optical disc D in the thickness direction.
[0029]
As shown in FIG. 1 (A), the optical disc D has a disk shape with an outer diameter of φ120 mm, and a center hole 102 with a φ15 mm is formed substantially at the center. In the optical disc D, the clamping area 103 is set between φ26 mm and φ33 mm, and the image forming area 104 is set between, for example, φ44 mm and φ118 mm on the label surface 31.
[0030]
As shown in FIG. 1B, the optical disc D is a transparent substrate 33 made of polycarbonate or the like having a thickness of 1.2 mm, a recording layer 34, a reflective layer 35, a reflectance changing layer (reflectance changing layer) 37, and a protection. The layers 38 are sequentially laminated so that the whole is integrally formed.
[0031]
Further, as shown in FIG. 1C, the optical disc D has a configuration in which a transparent layer 36 is provided between the reflective layer 35 and the reflectance changing layer 37 of the optical disc D shown in FIG. May be.
[0032]
In FIG. 1C, a recording layer 34 is a layer for recording data by irradiating a laser beam from the recording surface 32 side as is well known. The reflective layer 35 reflects the laser light emitted from the label surface 31 side and the recording surface 32 side. The transparent layer 36 is formed of a transparent material provided between the reflective layer 35 and the reflectance changing layer 37. The reflectance changing layer 37 is a translucent layer whose reflectance changes in a specific wavelength band of light when irradiated with laser light from the label surface side of the optical disc D. The protective layer 38 is a transparent layer that protects the reflectance changing layer 37 from the outside.
[0033]
FIG. 2 is a view showing the relationship between the wavelength and the reflectance of the laser beam applied to the reflectance changing layer of the optical disc, and the cross section of the optical disc. In FIG. 2B, the recording surface side pre-groove is not shown.
[0034]
Here, in the conventional optical disc, when the laser beam is irradiated from the label surface side, the reflectance is greatly changed (decreased) at all wavelengths of the light in the visible light characteristic changing layer. In addition, the reflectance may change particularly greatly depending on the wavelength of the laser light applied to the optical disk. As described above, when the reflectance of light greatly decreases on the label surface of the optical disc, the conventional optical disc apparatus cannot perform tracking servo or focus servo, so that it is impossible to read and redraw an image formed on the optical disc. It was impossible. Also, when the image becomes thin after drawing an image on the label surface of the optical disk due to the influence of the surrounding environment, the light reflectivity is somewhat improved, but there are many cases where tracking servo and focus servo cannot be performed. Furthermore, in order to read and redraw an image formed on an optical disk, the image formed on the optical disk must be accurately traced and read. However, in conventional optical disks and optical disk devices, image reading is accurately performed. Could not do.
[0035]
Therefore, the optical disc D of the present invention has two characteristic configurations that can redraw an image formed on the label surface side.
[0036]
First, when the optical disc D is irradiated with laser light having a predetermined wavelength (recording wavelength) λ1 from the label surface side, the optical disc D is thermally or photosensitive and has a reflectance in a specific wavelength band of light not including the wavelength λ1. A reflectance changing layer 37 that greatly changes (decreases) is provided. That is, as shown in FIG. 2A, the optical disc D of the present invention has a predetermined reflectance in the entire wavelength band of light before the laser beam is irradiated from the label surface side to draw an image. On the other hand, after the image is drawn by irradiating the label surface of the optical disc D with the laser beam having the wavelength λ1, the reflectance is greatly reduced in a specific wavelength band centered on the wavelength (reproduction wavelength) λ2, but the wavelength λ1 is the center. In other wavelength bands such as the wavelength band, the reflectance hardly changes.
[0037]
The optical disk D of the present invention can draw an image by irradiating the label surface of the optical disk D with a laser beam by utilizing the above-described features. In addition, when the image is redrawn because the color of the image has become lighter, the tracking servo and focus servo are stabilized by irradiating light with a wavelength band in which the reflectance hardly changes (laser light of wavelength λ1). Can be done. In addition, in order to read out the image drawn on the label surface, the image is detected by irradiating light of a specific wavelength band (laser light of wavelength λ2) whose reflectance changes (decreases) and detecting the change in reflectance. Can be read.
[0038]
Second, the optical disc D has a pre-groove on the label surface side. When the pregroove is formed on the label surface side of the optical disk D (CD-R), as shown in FIG. 2B, the spiral is formed at a pitch of 1.5 to 1.6 [mu] m, similar to the pregroove formed on the recording surface side. A pre-groove may be formed in a shape. The width of the pregroove is preferably 0.5 to 0.7 μm as in the case of the pregroove formed on the recording surface side, and wobbles meandering at a predetermined cycle may be formed so that the position on the label surface can be seen. Further, a land pre-pit (LPP) may be provided as in a DVD-R or DVD-RW. As described above, by forming the pre-groove and the wobble or LPP on the label surface of the optical disc D, it is possible to read the image at a very fine pitch and accurately redraw the image.
[0039]
In the case where the pregroove is also formed on the label surface side of the optical disc D, the pregroove must be formed on both sides of the optical disc D. For example, two discs are bonded to each other at the reflective layers 35a and 35b. It is preferable to use a single optical disk D.
[0040]
The reflectance changing layer 37 formed on the optical disk D may be made of a material containing, for example, an IR (infrared rays) dye that is a laser light absorbing dye, a leuco dye (leuco dye), and a developer. . The IR dye generates heat by absorbing laser light having a wavelength of 780 nm, which is the wavelength band of infrared light. In addition, as the leuco dye, a leuco dye that undergoes a chemical change with the developer due to heat generation of the IR dye, for example, a material whose reflectivity at 610 to 750 nm, which is the wavelength band of red light, is significantly reduced is used. FIG. 3 is a Venn diagram showing the three primary colors of light. When the label surface of the optical disk D is white, when the laser beam having a wavelength of 780 nm is irradiated, the reflectance of the red light is reduced and, as shown in FIG. 3, the color is developed to cyan which is a mixed color of blue and green. .
[0041]
Further, when a leuco dye having a substantially reduced reflectance of 610 to 750 nm which is a wavelength band of red light and a reflectance of 500 to 560 nm which is a wavelength band of green light is used, the label surface of the optical disc D is used. If the laser beam is white, when it is irradiated with a laser beam having a wavelength of 780 nm, it is colored blue as shown in FIG.
[0042]
As described above, when the laser beam in the infrared region is irradiated on the label surface of the optical disc D, the reflectance in the visible light region in the reflectance changing layer 37 can be greatly changed (decreased). It will appear colored.
[0043]
As the laser light absorbing dye, for example, azo dyes, cyanine dyes, phthalocyanine dyes which are IR (infrared) absorbing dyes are suitable.
[0044]
The leuco dye is preferably one that develops a color by causing a chemical reaction with the developer at a temperature of about 80 to 150 ° C., for example. As the leuco dye, for example, a fluorane compound or a phthalide compound may be used. As the developer, for example, a phenol-based compound may be used.
[0045]
Further, as a material used for the reflectance changing layer 37, the laser beam having a wavelength of 780 nm incident from the side of the label surface 31 is not exposed to light when the power is less than 1.5 mW, for example, but is exposed and develops color when the power is 1.5 mW or more. Various materials can also be used.
[0046]
In this way, by irradiating the label surface of the optical disc D with laser light having a predetermined wavelength, the reflectance does not change at the wavelength of the irradiated laser light, and the reflectance of the laser light having a wavelength different from that of the irradiated laser light. The user or manufacturer can form a desired image at an arbitrary position.
[0047]
The optical disk recording / reproducing apparatus normally performs tracking servo almost accurately even when the optical disk D has no pregroove when the track pitch (interval of the locus of the laser beam irradiated spirally) is about 80 μm to 100 μm. be able to. Therefore, if there is no problem even if the accuracy of the image is slightly reduced, such as an image formed on the label surface of the optical disk D, or if the image is formed by overwriting multiple times, the pre-groove May not be formed. Further, even when there is no need to redraw an image formed on the label surface of the optical disk D, it is possible to use an optical disk in which no pregroove is formed on the label surface side. In this case, the manufacturing process of the optical disk can be simplified, so that the cost can be reduced.
[0048]
Next, the configuration of the optical disc recording apparatus according to the embodiment of the present invention will be described. FIG. 4 is a block diagram showing the configuration of the optical disc recording apparatus according to the embodiment of the present invention. The optical disc recording / reproducing apparatus 1 not only can record data on the recording surface of the optical disc D and reproduce data recorded on the recording surface of the optical disc D, but also forms an image on the label surface of the optical disc D. be able to. In the following description, a configuration and an operation for forming an image on the label surface of the optical disc D of the optical disc recording / reproducing apparatus 1 will be described, and a well-known method for recording data on the recording surface of the optical disc D and reproducing data on the optical disc D will be described. The illustration and description of the configuration and operation are omitted.
[0049]
The optical disc recording / reproducing apparatus 1 has a configuration in which an image drawing / reading unit 20 and a calculation unit 21 are connected via an interface circuit 9. The image drawing / reading unit 20 includes a spindle motor 2, a frequency generator 3, a spindle motor control circuit 4, a guide rail 5, a feed motor 6, an optical pickup 7, a servo circuit 8, an interface circuit 9, an image data buffer memory 10, and drawing timing. A control circuit 11, a laser pulse gradation control circuit 12, a laser power control circuit 13, and a control circuit 14 are provided.
[0050]
The calculation unit 21 includes a control unit 22, a storage unit 23, a display unit 24, and an operation unit 25. The calculation unit 21 can be realized by a personal computer or the like.
[0051]
The spindle motor 2 is a motor that rotationally drives the optical disc D. Further, an optical disk holding mechanism including a turntable 15 for holding (chucking) the optical disk D is provided at the tip of the rotating shaft of the spindle motor 2.
[0052]
The frequency generator 3 outputs a signal for detecting the position (angle) and the number of rotations of the rotation shaft of the spindle motor 2 to the spindle motor control circuit 4. The frequency generator 3 outputs a pulse signal at regular intervals (for example, 18 times) at regular intervals while the spindle motor 2 makes one rotation at a constant speed. The spindle motor control circuit 4 can detect the relative position (angle) and the rotation speed of the optical disk D attached to the rotation shaft of the spindle motor 2 by detecting this pulse signal.
[0053]
The spindle motor control circuit 4 controls the rotation of the spindle motor 2 based on the pulse signal output from the frequency generator 3.
[0054]
The guide rail 5 supports the optical pickup 7 so that the optical pickup 7 faces the optical disc D and moves in the radial direction of the optical disc D.
[0055]
The feed motor 6 is a motor that supplies a driving force for moving the optical pickup 7 in the radial direction of the optical disc D.
[0056]
The optical pickup 7 includes a laser diode L1 that irradiates laser light having a wavelength of 780 nm that is a wavelength band of infrared light, a laser diode L2 that emits laser light having a wavelength of 670 nm that is a wavelength band of red light, an optical system such as a lens and a mirror, A return light (reflected light) light receiving element, a focusing servo mechanism, a tracking servo mechanism, and the like are provided (not shown). Further, when recording and reproducing data, and when forming an image on the label side, the laser diode L1 or L2 irradiates the optical disk D with laser light, receives the return light from the optical disk D, and generates a light reception signal. The corresponding tracking error signal and focusing error signal are output to the servo circuit 8. The focusing servo mechanism is a servo mechanism for keeping the distance between the lens of the optical pickup 7 and the data recording surface of the optical disk D constant. The tracking servo mechanism is a servo mechanism for always irradiating laser light onto a pre-groove (recording track) formed on the recording layer or label surface side of the optical disc D. Further, the optical pickup 7 is provided with a laser power monitoring photodiode. When this photodiode receives a part of the laser beam emitted from the laser diode L1 or L2, it corresponds to the power of the received laser beam. A current is output, and this current is supplied to the laser power control circuit 13.
[0057]
The servo circuit 8 performs focusing control (focusing servo) and tracking control (tracking servo) of the optical pickup 7 and feed control of the optical pickup 7 by the feed motor 6 so that the optical pickup 7 is always in an appropriate position. To do.
[0058]
The interface circuit 9 is a relay circuit for sending the signal sent from the arithmetic unit 21 to the image data buffer memory 10 and the control circuit 14.
[0059]
The image data buffer memory 10 temporarily stores the image data transferred from the arithmetic unit 21 via the interface circuit 9 and outputs the image data to the laser pulse gradation control circuit 12.
[0060]
The drawing timing control circuit 11 detects the angle of the optical disk D output from the spindle motor control circuit 4 in order to form an image at a predetermined position on the label surface side of the optical disk D set by the user. Based on the control signal output from the circuit 14, the timing for outputting data from the image data buffer memory 10 and the laser pulse gradation control circuit 12 is controlled.
[0061]
The laser pulse gradation control circuit 12 converts the image data into a laser irradiation pattern and outputs it to the laser power control circuit 13.
[0062]
The laser power control circuit 13 controls the power of laser light emitted from the laser diodes L1 and L2 of the optical pickup 7. Specifically, the laser power control circuit 13 is optimized based on the value of the current output from the photodiode of the optical pickup 7 and information indicating the optimum target value of the laser power transmitted from the control circuit 14. Control is performed so that the laser diode of the optical pickup 7 emits a laser beam having a suitable laser power.
[0063]
The control circuit 14 includes a CPU, a ROM, a RAM, and the like. The spindle motor control circuit 4, the servo circuit 8, the drawing timing control circuit 11, and the laser power of the optical disc recording / reproducing apparatus 1 according to a program stored in the ROM. A control signal is transmitted to the control circuit 13 and the like to control each unit connected thereto. In addition, signals are exchanged with the arithmetic unit 21 via the interface circuit 9.
[0064]
In the calculation unit 21, the control unit 22 controls each unit and communicates with the control circuit 14. The storage unit 23 stores an image creation program for forming an image on the label surface side of the optical disc D. The display unit 24 displays contents that the control unit 22 wants to transmit to the user. The operation unit 25 is for the user to operate the calculation unit 21.
[0065]
The optical disc recording / reproducing apparatus 1 drives the optical disc D by a CAV (Constant Angular Velocity) method when an image is formed on the label surface of the optical disc D. Therefore, at this time, the servo circuit 8 controls so that the rotation speed of the spindle motor 2 detected by the frequency generator 3 coincides with the set rotation speed.
[0066]
Next, a configuration for recording data on the label surface of the optical disc D by the optical disc recording / reproducing apparatus 1 will be described. FIG. 5 shows the positional relationship between the optical pickup and the label surface of the optical disk. In FIG. 5, since the configuration of the optical pickup is simplified and displayed, it is actually necessary to provide a plurality of optical components.
[0067]
The optical pickup 7 is preferably configured as follows. That is, as shown in FIG. 5A, a laser diode L1 (wavelength 780 nm), a laser diode L2 (wavelength 670 nm), a half mirror 16, and an objective lens 17 are provided inside the optical pickup 7. The laser light emitted from the laser diode L1 and the laser light emitted from the laser diode L2 when the image is drawn on the label surface of the optical disc D and when the image on the label surface of the optical disc D is read out. Arrange them so that they can be switched.
[0068]
In the configuration shown in FIG. 5A, when drawing on the label surface of the optical disc D by the optical disc recording / reproducing apparatus 1, a laser is focused from the label surface 31 side of the optical disc D onto, for example, the reflection surface 35. When the laser light of light power is irradiated from the diode L1, the reflectance of the laser beam having a wavelength different from that of the irradiated laser light is changed in the reflectance changing layer 37 without changing the reflectance at the wavelength of the irradiated laser light. be able to. In the reflectance changing layer 37, the reflectance of light having a wavelength different from that of the irradiated laser light is changed (decreased) to develop color. Therefore, a user or a manufacturer can form a desired image by irradiating a laser beam having a wavelength of 780 nm to an arbitrary position of the reflectance changing layer 37 formed on almost the entire label surface of the optical disc D. .
[0069]
  On the other hand, when redrawing the image formed on the label surface of the optical disc D, first, when reading the image formed on the label surface side, the laser diode L2 is turned on and laser light of a certain amount (read power) is emitted. Irradiate and read the reflected light to detect the imageTheIn this case, since the reflectance change (decrease) of the laser beam having a wavelength of 670 nm is large on the optical disc D, tracking servo and focusing servo may not be performed. Therefore, 780 nm laser light is used so that tracking servo and focusing servo can be reliably performed when laser light with a wavelength of 670 nm is irradiated.TheWhen an image is drawn by irradiation, the image may be formed by blinking laser light at a predetermined interval. That is, in the case of a normal optical disk recording / reproducing apparatus, if it is about 1 mm, the servo can be continued without failing without performing the focus servo or tracking servo. Therefore, the control circuit 14 of the optical disc recording apparatus 1 is preferably set so that the distance at which each servo cannot be performed does not exceed 1 mm.
[0070]
  Further, the optical pickup 7 can be configured as follows. That is, as shown in FIG. 5B, the spot of the laser beam emitted from the laser diode L1 and the spot of the laser beam emitted from the laser diode L2 are configured to coincide with each other in the reflective layer of the optical disc D. Good. In this configuration, when an image is formed on the label surface side of the optical disk D, the laser light of the write power is irradiated from the laser diode L1 to the label surface side of the optical disk D, and focus servo or tracking servo is performed.TheAn image can be formed while it is being performed. Further, when the color of the image formed on the optical disc D becomes light, when reading the image, the laser diode L1 and the laser diode L2 are irradiated with laser light having a read power, and the wavelength 780 nm emitted from the laser diode L1 is irradiated. The focus servo and the tracking servo are performed with the laser light of, and the image on the label surface side is read with the laser light with a wavelength of 670 nm irradiated from the laser diode L2. By doing so, it is possible to accurately detect the image drawn on the optical disc D and the recorded position of the image. Therefore, as in the case described with reference to FIG. 5A, it is not necessary to adjust the blinking interval of the laser light at the time of image formation, and a gapless image can be formed.
[0071]
Next, laser light irradiation timing in the optical disc recording / reproducing apparatus 1 will be described. FIG. 6 is a timing chart for explaining the emission timing of the laser beam. The optical disk recording / reproducing apparatus 1 switches the power of the laser light irradiated to the label surface side of the optical disk D in two steps, as shown in FIG. That is, when changing the reflectance of the reflectance changing layer 37 to cause color development, laser light having a light power is irradiated at a wavelength λ1. Also, when focus servo or tracking servo is performed without changing the reflectance of the reflectance change layer 37 without changing the reflectance, laser light having a servo power weaker than the write power is irradiated. The optical disc recording / reproducing apparatus 1 emits laser pulses at a predetermined interval in order to monitor the write power even during a colorless period.
[0072]
As shown in FIG. 6B, when the optical disc D is irradiated with the laser beam irradiation power of wavelength λ1 as the light power, the reflectance changing layer 37 is heat sensitive or photosensitive, and the reflectance of the laser beam of wavelength λ2. Changes (color develops). At this time, as shown in FIG. 6C, in the optical disc D, the reflectance of the laser beam having the wavelength λ1 does not change. Therefore, even if the reflectance changing layer 37 is colored, it is possible to stably perform focus servo and tracking servo by irradiating the laser beam having the wavelength λ1.
[0073]
Further, as described above, when an image is formed on the label surface side of the optical disc D, when the optical disc recording / reproducing apparatus 1 irradiates a laser beam having a constant power at a wavelength λ2 different from the wavelength λ1, the light power has a wavelength λ1. Since the reflectance of the portion irradiated with the laser light changes, the reflected light as shown in FIG.
[0074]
Since the optical disc D of the present invention exhibits the characteristics as described above, when redrawing an image, as described above, the laser beam of the reproduction wavelength is irradiated to the label surface side of the optical disc D, and image data, Then, after reading the position information of the pre-groove, the image already recorded on the label surface side of the optical disk D can be overwritten by irradiating the label surface side of the optical disk D with laser light having a recording wavelength. Therefore, when the color of the image formed on the reflectance change layer 37 becomes light, the color density can be increased.
[0075]
Next, the operation of forming an image on the label surface of the optical disc D in the optical disc recording / reproducing apparatus 1 of the present invention will be described. FIG. 7 is a diagram showing an image of an orthogonal coordinate system and an image of a polar coordinate system for an image. The optical disc recording / reproducing apparatus 1 forms an image on the label surface of the optical disc D by irradiating the optical pickup 7 with light power laser light in order to record data on the recording surface of the optical disc D while rotating the optical disc D. . Therefore, the optical disc recording / reproducing apparatus 1 uses a laser beam irradiation pattern for an image formed on the optical disc D based on an image in a polar coordinate system as shown in FIG.
[0076]
Here, a general image handled by a computer or the like is an image of an orthogonal coordinate system and not an image of a polar coordinate system, as shown in FIG. Therefore, the calculation unit 21 that transmits the image data to the optical disc recording / reproducing apparatus 1 converts the image data of the orthogonal coordinate system into the image data of the polar coordinate system and transmits the image data to the optical disc recording / reproducing apparatus 1. In the optical disk recording / reproducing apparatus 1, the laser pulse gradation control circuit 12 continuously applies laser irradiation pattern data for forming an image by irradiating a laser beam while rotating the optical disk D based on the image data in the polar coordinate system. Data connected to each other (hereinafter referred to as serial data) is created. Based on this serial data, an image is formed on the label surface 31 side of the optical disc D from the designated recording start position (R0, θ0).
[0077]
For example, the calculation unit 21 uses the control unit 22 to create image formation data based on image data in the bmp (bitmap) format, which is an example of image data in an orthogonal coordinate system. FIG. 8 is an image diagram for image conversion from an orthogonal coordinate system to a polar coordinate system. First, for example, the intensity of the laser beam irradiation power is adjusted according to the gradation, or the bmp image is dithered so that a predetermined gradation can be expressed when the image is formed. Dither processing is a method for expressing light and shade by changing the distribution and density of dots. Subsequently, the dithered image in the bmp format is arranged on the polar coordinates, one arbitrary point is determined, and the image data in the bmp format is converted into image data in the polar coordinate system. That is, as shown in FIG. 7, with the lower right corner (x, y) = (X0, Y0) of the image in the Cartesian coordinate system as a reference point
r = √ (X²+ Y²), Θ = tan^-1(Y / X)
Conversion based on the formula Then, in order to form an image by irradiating the optical disc D with laser light by the optical disc recording / reproducing apparatus 1, the polar coordinate system image data is converted into serial data. The optical disc recording / reproducing apparatus 1 forms an image on the label surface of the optical disc D by irradiating the laser beam from the designated recording start position based on the serial data thus created.
[0078]
Further, the calculation unit 21 can easily convert an image in the orthogonal coordinate system into an image in the polar coordinate system as an image to be drawn on the label surface of the optical disc D by the control unit 22. FIG. 9 is a diagram illustrating an example in which an image in an orthogonal coordinate system is simply converted into an image in a polar coordinate system. That is, as shown in FIG. 9, the row (x) of the rectangular coordinate system image (bmp format) is r in the polar coordinate system image, and the column (y) of the rectangular coordinate system image (bmp format) is the polar coordinate system. Is converted to θ of the image. When an image is formed based on the image data obtained by this conversion, if the image in the orthogonal coordinate system is rectangular as shown in FIGS. 9A and 9B, the image in the polar coordinate system is shown in FIG. , (D), a circular arc having a predetermined width (or a trapezoid whose bottom is shorter). For this reason, the width of the image becomes wider toward the outer periphery of the optical disc D, and the formed image is distorted. Further, the more the position where an image is formed is on the inner peripheral side of the optical disc D, the greater the distortion. However, when displaying characters, symbols, barcodes, etc. on the image, this distortion is not a problem, and the time required to create the image formation data can be shortened. This is a useful method for forming.
[0079]
In the present invention, as an image to be drawn on the optical disc D, a media ID, a serial number, or the like can be drawn with a binary code or a barcode. In the arithmetic unit 21 of the optical disc recording / reproducing apparatus 1, when an input such as a serial number is input from the operation unit 25, the data input by the control unit 22 is converted into a binary code or a barcode, and an image is read by the drawing / reading unit 20. Drawing on the label surface of the optical disc D is possible.
[0080]
FIG. 10 is a drawing example of a barcode on an optical disc. In the optical disc recording / reproducing apparatus 1, when a pre-groove is formed on the label surface of the optical disc D, a binary code or a barcode can be drawn along the pre-groove as shown in FIG. When pregrooves are formed on the label surface of the optical disc D, the wobble and LPP are provided as described above, so that these codes can be accurately read out by the optical disc recording / reproducing apparatus 1.
[0081]
Further, when the pre-groove is not formed on the label surface of the optical disc D, when drawing a binary code or a barcode as shown in FIG. Draw a code in a bar shape in the radial direction.
[0082]
As a result, even if the radial feed pitch of the optical disc recording / reproducing apparatus 1 is about 80 μm to 100 μm as described above, the binary code and the barcode can be easily read after drawing. In addition, by drawing the barcode as shown in FIG. 10B on the label surface of the optical disc D, it is possible to read the drawn barcode not only by the optical disc recording / reproducing apparatus 1 but also by a barcode reader. Become.
[0083]
Next, the operation of the optical disc recording / reproducing apparatus of the present invention will be described based on a flowchart. FIG. 11 is a flowchart for explaining the operation of the optical disc recording / reproducing apparatus.
[0084]
First, the user inputs whether to draw an image on the label surface of the optical disc D or to redraw the image drawn on the optical disc D from the operation unit 25 of the optical disc recording / reproducing apparatus 1. When there is an image drawing input from the operation unit 25 (s1), the control unit 22 reads and activates the image creation program stored in the storage unit 23 (s2). Subsequently, the display unit 24 displays the content for inquiring whether to draw an image on the label surface of the optical disc D or to draw a code such as a barcode (s3).
[0085]
When the control unit 22 detects that the code input is selected by the operation unit 25, the control unit 22 causes the display unit 22 to display the content prompting the user to input numbers and symbols to be displayed as codes (s4). When a number or symbol is input from the operation unit 25 (s5), the control unit 22 converts the input number or symbol into a code such as a barcode and displays an image drawn on the label surface of the optical disc D as a display unit. 24 is displayed (s6). Further, the contents for inquiring whether to edit the barcode position or the like are displayed.
[0086]
When there is an input for editing from the operation unit 25, the control unit 22 performs an editing process in accordance with a user operation (s8). Then, when the user's editing process is completed, the control unit 22 causes the display unit 24 to display content that prompts the user to set the optical disc D (s9). When the control circuit 14 detects that the user has set the optical disc D so that the label surface of the optical disc D faces the optical pickup 7 (s10), the laser light of the light power from the laser diode L1 is applied to the label surface of the optical disc D. The image is drawn by irradiation (s11). When the drawing of the image on the label surface is completed, the control unit 22 displays the fact on the display unit 24 (s12) and ends the process.
[0087]
In s3, when the control unit 22 detects that the user has selected to draw an image, the control unit 22 prompts the user to set an image to be drawn on the label surface of the optical disc D (image data in an orthogonal coordinate system such as an arbitrary character or painting). The contents are displayed on the display unit 24 (s13). When the control unit 22 detects that the user has set an image (s14), the control unit 22 displays an image of the image drawn on the label surface of the optical disc D on the display unit 24 (s15). And the control part 22 performs the process after s7.
[0088]
In addition, when there is an image redrawing input from the operation unit 25 (s1), the control unit 22 causes the display unit 24 to display content for prompting the user to set the optical disc D (s21). When the control circuit 14 detects that the user has set the optical disk D so that the label surface of the optical disk D faces the optical pickup 7 (s22), the control circuit 14 irradiates a laser beam of read power from the laser diode L2 (or An image drawn on the label surface of the optical disc D is read (s23) by irradiating laser light of read power from the laser diode L1 and the laser diode L2. Subsequently, the control circuit 14 redraws the image on the label surface of the optical disc D based on the image read in s23 (s24). When the drawing of the image on the label surface is completed, the control unit 22 displays the fact on the display unit 24 (s25) and ends the process.
[0089]
In the above description, the recording wavelength is the infrared light wavelength (780 nm) and the reproduction wavelength is the red light (670 nm) of the visible light. However, the present invention is not limited to this. For example, by setting the recording wavelength to the visible light region and the reproduction wavelength to the infrared light region or the ultraviolet light region, it becomes impossible to see the image formed by the human eye, and it can be used for applications such as security. .
[0090]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0093]
  lightDisc recording and playback deviceProvided between the protective layer and the reflective layer is a reflectance changing layer in which the reflectance of light in a specific wavelength band that does not include the wavelength λ1 but includes the wavelength λ2 changes when irradiated with laser light having the wavelength λ1.An image can be written by irradiating the optical disk with a laser beam having a write power of wavelength λ1, and an image can be read by irradiating a laser beam having a read power of wavelength λ2.
  In addition, focus servo and tracking servo can be stably performed, and a change in reflectance can be detected to reliably read an image drawn on the label surface of the optical disc.
[0094]
  further,Since the laser beam having the read power of the wavelength λ1 that does not change the reflectance of the optical disk can be irradiated to the position irradiated with the laser beam of the wavelength λ2, the image drawn on the label surface of the optical disk is read along the pregroove. In addition, the focus servo and tracking servo can be performed stably. As a result, when the color of the image formed on the label surface of the optical disc becomes lighter due to the passage of time or environmental change, it can be easily redrawn.
[0095]
  In addition, a barcode can be drawn on the label surface of the optical disc of the present invention.The
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of an optical disc D. FIG.
FIG. 2 is a diagram showing the relationship between the wavelength and the reflectance of laser light applied to the reflectance changing layer of the optical disc, and a cross section of the optical disc.
FIG. 3 is a Venn diagram representing the three primary colors of light.
FIG. 4 is a block diagram showing a configuration of an optical disc recording apparatus according to an embodiment of the present invention.
FIG. 5 is a diagram showing a positional relationship between an optical pickup and a label surface of an optical disc.
FIG. 6 is a timing chart for explaining the emission timing of laser light.
FIG. 7 is a diagram illustrating an image in an orthogonal coordinate system and an image in a polar coordinate system for an image.
FIG. 8 is an image diagram for image conversion from an orthogonal coordinate system to a polar coordinate system.
FIG. 9 is a diagram illustrating an example in which an image in an orthogonal coordinate system is simply converted into an image in a polar coordinate system.
FIG. 10 is a drawing example of a barcode on an optical disc.
FIG. 11 is a flowchart for explaining the operation of the optical disc recording / reproducing apparatus.
[Explanation of symbols]
1-Optical disk recording device
2-spindle motor
3-frequency generator
7-Optical pickup
14-Control circuit
20-Image drawing / reading unit
21-Calculation unit

Claims (5)

Provided between the protective layer and the reflective layer is a reflectivity changing layer in which the reflectivity of light in a specific wavelength band not including the wavelength λ1 but including the wavelength λ2 is changed by irradiation with laser light having the wavelength λ1 from the label surface side. An optical disc recording / reproducing apparatus that reads out an image and rewrites an image by irradiating a laser beam from the label side of the optical disc,
A first laser beam irradiation means for irradiating a laser beam having a wavelength λ1 to the label surface side of the optical disc;
A second laser beam irradiation means for irradiating a laser beam having a wavelength λ2 to the label surface side of the optical disc;
When reading an image on the label surface side of the optical disc, the second laser light irradiation unit is irradiated with a laser beam of read power from the label surface side of the optical disc, and the first laser light irradiation unit is Irradiate laser light with read power from the label side of the optical disc,
When rewriting an image on the label surface side of the optical disc, control means for irradiating the first laser light irradiating means with laser light of write power;
An optical disc recording / reproducing apparatus comprising:   When reading the image on the label surface side of the optical disc, the control means irradiates the first laser light irradiating means with laser light of read power, performs tracking servo and focus servo, and performs the second servo. The optical disk recording / reproducing apparatus according to claim 1, wherein the laser beam irradiation unit is irradiated with a laser beam having a read power to detect a change in reflectance.   The said 1st laser beam irradiation means irradiates the laser beam of wavelength (lambda) 1 to the location which the said 2nd laser beam irradiation means is irradiating the laser beam of wavelength (lambda) 2 to the said optical disk. Optical disc recording / reproducing apparatus. 4. The optical disc recording / reproducing apparatus according to claim 1, further comprising: a barcode conversion unit that converts arbitrary information into a barcode and irradiates the writing unit with a laser beam having a wavelength λ1 in a barcode drawing pattern. . Provided between the protective layer and the reflective layer is a reflectivity changing layer in which the reflectivity of light in a specific wavelength band not including the wavelength λ1 but including the wavelength λ2 is changed by irradiation with laser light having the wavelength λ1 from the label surface side. An optical disc,
A first laser beam irradiating means for irradiating a laser beam having a wavelength λ1 to the label surface side of the optical disc; a second laser beam irradiating device for irradiating a laser beam having a wavelength λ2 to the label surface side of the optical disc; When reading the image on the label surface side, the second laser beam irradiating unit is irradiated with a laser beam having a read power from the label surface side of the optical disc, and the first laser beam irradiating unit is irradiated with the first laser beam irradiating unit. from the label surface side by irradiating a laser beam of read power, the light in writing images re on the label surface of the disc, the laser beam of the first label surface or Lara Itopawa of the optical disc to the laser beam irradiation means An optical disc recording / reproducing apparatus comprising:
An optical disc drawing system consisting of

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