JP3956146B2 - Optical disk device - Google Patents

Description

The present invention relates to an optical disc apparatus that records electronic information and visible information by irradiating an optical disc with a laser beam.

Conventionally, CD (Compact Disk) and DVD (Digital Versatile)
By irradiating a laser beam to an optical disc such as a disk (digital versatile disc), electronic information such as music information and video information recorded on the optical disc is reproduced, and such electronic information is applied to the optical disc. An optical disc apparatus capable of recording is provided.

When electronic information is recorded on an optical disc with such an optical disc device, it is convenient if the recorded content can be recognized by appearance, so the user can use a dedicated printer device to indicate characters recorded on the optical disc. Etc. (for example, song titles, movie titles, etc.) are printed on a circular sheet, and this sheet is pasted on the surface opposite to the recording surface of the optical disk (hereinafter referred to as the label surface).

However, in this method, the user needs to prepare a dedicated printer device, and needs to perform complicated operations such as printing a sheet with the dedicated printer device and pasting the printed sheet on an optical disk. .

Therefore, in recent years, the recorded content of the optical disc can be visualized by irradiating a predetermined area that becomes the label surface of the optical disc with a laser beam irradiated on the recording surface of the optical disc at the time of reproduction or recording, and changing the color development etc. of the irradiated portion. An optical disc apparatus capable of recording (hereinafter also referred to as printing) visible information (for example, an image made up of characters indicating a song title, a movie title, etc.) on a label surface of the optical disc has been proposed (for example, a patent). References 1-3).
JP 2003-203348 A JP 2004-213802 A JP 2003-51118 A

However, in the case of the conventional optical disk apparatus (optical disk recording apparatus) described in Patent Document 1, the user still needs to perform complicated work. That is, when recording the electronic information, the user attaches the optical disc so that the recording surface side of the optical disc is irradiated with a laser beam, and when recording the visible information on the optical disc, the label surface of the optical disc It was necessary to perform a complicated operation of turning the optical disc over and remounting it so that the laser beam was irradiated to the side. Moreover, since it is necessary to perform recording of electronic information and recording of visible information separately, there is a problem that it takes time to perform both recording.

In addition, the conventional optical disk device described in Patent Document 2 is provided with a laser array that irradiates the three laser beams arranged so that the focal points of the three laser beams to be irradiated are in the radial direction of the optical disk. Information (image) recording (formation) can be performed at high speed, but again, electronic information recording and visible information recording need to be performed separately,
There was a problem that it took time to record both.

In addition, the conventional optical disk device (recording device) described in Patent Document 3 is also electronic information (
Data recording and visual information (visual image) recording need to be performed separately, and there is a problem that it takes time to perform both recordings.

Therefore, as an optical disk apparatus that solves these problems, that is, there is no need to perform the complicated work of mounting the optical disk upside down, the recording of electronic information and the recording of visible information can be performed efficiently by irradiating a laser beam. As an optical disk device for performing, an optical pickup having a plurality of light sources for emitting a laser beam for recording electronic information, and a light source for emitting a laser beam for recording electronic information from one of the plurality of light sources The other one is a light source that emits a laser beam for recording visible information, and both laser beams are irradiated from one side of the optical disc to record electronic information and visible information simultaneously. An optical disk device designed to be performed is conceivable.

However, in such an optical disc apparatus, a laser beam for recording electronic information and a laser beam for recording visible information may be emitted simultaneously from the optical pickup. There is a problem that the temperature rise of the optical pickup becomes larger than when the beams are emitted separately in time division, the life of the optical pickup is shortened, or in the worst case, it is thermally destroyed. .

In addition, when both laser beams are emitted simultaneously, the temperature rise of the optical disk irradiated with these laser beams also becomes larger than when each laser beam is emitted separately in a time division manner. May cause deterioration of the portion of the optical disk irradiated with the laser beam, and the shape and size of the recorded electronic information (pits) and visible information (images) differ from the shape and size that should be recorded. As a result, there is a problem that recording may not be performed accurately.

The present invention has been made to solve the above-described problems, and when performing label printing of an optical disk, it is not necessary to perform a complicated operation of turning the optical disk upside down and irradiating it with a laser beam. Provided is an optical pickup that can efficiently and accurately form a visible image on a label surface of an optical disc, and that can prevent overheating of an optical pickup that emits a laser beam and an optical disc irradiated with the laser beam. For the purpose.

In order to achieve the above object, an invention according to claim 1 is directed to an information recording layer in which grooves are formed and electronic information is reproduced or recorded by irradiation with a first laser beam, and a first laser. A label layer on which visible information is recorded by being irradiated with a second laser beam having a wavelength band different from that of the beam, and a reflectance of the first laser beam provided between the information recording layer and the label layer. Is applied to the optical disc provided with a dichroic reflective film having a higher reflectance than that of the second laser beam by reproducing the first and second laser beams from the information recording layer side. An optical disc apparatus for recording and recording visible information,
A first laser diode that emits a first laser beam; an intensity of the first laser beam that drives and drives the first laser diode; and a first intensity that records electronic information on the information recording layer; A first laser diode driver that switches to a second intensity that is weaker than a first intensity and that is used to reproduce electronic information recorded in the information recording layer; and a second laser diode that emits a second laser beam A second laser diode driver for driving the second laser diode, an objective lens for condensing the first laser beam on the information recording layer and condensing the second laser beam on the label layer, A tracking actuator that drives the objective lens in the radial direction of the optical disc, and a focus actuator that drives the objective lens in the optical axis direction. And an optical pickup that receives a reflected light from the dichroic reflecting film of the first laser beam and outputs a light receiving signal based on the received reflected light, and the groove included in the light receiving signal. The tracking actuator is driven based on the positional information to control the tracking of the laser beam applied to the optical disc, and based on the focus information of the first laser beam in the information recording layer included in the light receiving signal. Servo processing means for driving the focus actuator to control the focus of the laser beam applied to the optical disk, temperature detecting means for detecting the temperature of the optical pickup, and recording electronic information and visible information on the optical disk To drive the first laser diode driver and to record When the intensity of the first laser beam emitted based on the electronic information is switched between the first intensity and the second intensity, and when the temperature detected by the temperature detecting means is higher than a predetermined temperature. Controlling the first laser diode driver so that the intensity of the emitted first laser beam becomes the second intensity;
The second laser diode driver is driven based on the visible information to be recorded, and the thinning rate is determined based on the gradation indicating the shade of the visible information included in the visible information to be recorded,
There is provided an optical disc apparatus comprising control means for performing thinning control of the emission time of the second laser beam at the determined thinning rate.

According to this configuration, the information recording layer of the optical disc is irradiated with the first laser beam from the optical pickup to record the electronic information, and the second layer from the optical pickup to the label layer of the optical disc. It is possible to simultaneously record the visible information on the label layer by irradiating the laser beam from the information recording layer side. At this time, the irradiated first laser beam is reflected by the dichroic reflecting film of the optical disc, so that it does not affect the label layer of the optical disc, and the irradiated second laser beam is the second laser beam. The light passes through the chromatic reflection film and reaches the label layer.

Further, when recording the electronic information and the visible information, the first laser beam is irradiated and the intensity of the first laser beam irradiated based on the electronic information to be recorded is the first intensity and the second intensity. The second laser beam is irradiated based on the visible information to be recorded. At this time, the servo processing means moves the objective lens of the optical pickup based on the position information of the groove of the optical disk included in the received light signal based on the reflected light from the dichroic reflecting film of the irradiated first laser beam. The tracking actuator to be driven is driven and tracking control of the first laser beam irradiated onto the optical disc is performed.

At the same time, the servo processing means drives a focus actuator that drives the objective lens of the optical pickup based on the focus information of the first laser beam irradiated to the optical disk included in the light reception signal, and irradiates the optical disk. Focus control of the first laser beam is performed. Thereby, since the first and second laser beams are condensed by the same objective lens, both the first and second laser beams are subjected to tracking control and focus control.

At this time, even if the first and second laser beams are simultaneously emitted from the optical pickup, the emission time of the second laser beam is thinned out by the control means, so that the temperatures of the optical pickup and the optical disc are reduced. The rise is suppressed. Further, since the emission time of the second laser beam is thinned at the thinning rate determined based on the gradation level indicating the density of the visible information included in the visible information to be recorded, the label layer has a visible light with a light and shade. Information is recorded.

Further, when the temperature detected by the temperature detecting means is higher than a predetermined temperature, the first laser diode driver is controlled so that the intensity of the emitted first laser beam becomes the second intensity. The temperature rise of the optical pickup is suppressed.

In the optical pickup and optical disc apparatus to which the present invention is applied, “visible information” means information that can be read visually, such as characters, symbols, images such as illustrations and photographs, and geometric patterns. “Electronic information” means information such as information recorded with digital symbols, the content of which is read by some reproducing device.

As described above, according to the present invention, the first and second laser beams are irradiated from the optical pickup to the optical disc from the side where the electronic information of the optical disc is reproduced or recorded, and the electronic information and the visible information are recorded. Since recording can be performed, it is possible to realize an optical disc apparatus that eliminates the need for complicated work of turning the optical disc upside down when performing label printing on the optical disc.

According to the invention, the optical information is recorded on the optical disc by irradiating the first laser beam from the optical pickup, and the visible information is irradiated by irradiating the second laser beam from the optical pickup. Recording can be performed simultaneously, so that an optical disc apparatus capable of efficiently performing label printing of the optical disc can be realized.

Further, according to the present invention, when label printing is performed, the first, the first, and the second laser beams based on the visible information to be recorded are irradiated on the basis of the reflected light of the first laser beam.
Since both the second laser beam are subjected to tracking control and focus control, an optical disc apparatus capable of accurately performing label printing on the optical disc can be realized.

According to the present invention, even if the first and second laser beams are simultaneously emitted from the optical pickup, the emission time of the second laser beam is thinned out by the control means, and the optical pickup and the optical disc Therefore, an optical pickup that emits a laser beam and an optical disc apparatus that can prevent overheating of the optical disc irradiated with the laser beam can be realized.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. An optical disc device according to the present embodiment includes an optical pickup having a light source that emits a laser beam for recording electronic information and a light source that emits a laser beam for recording visible information, and is provided from one surface of the optical disc. This is an optical disk device capable of simultaneously recording electronic information and visible information by irradiating both laser beams.

First, the configuration of an optical disc targeted by the optical disc apparatus according to the present embodiment will be described, and then the configuration and operation of the optical disc device will be described.

FIG. 1 is a side sectional view showing the structure of an optical disk assumed in this embodiment. Here, as an optical disc, an optical disc apparatus that performs recording and reproduction of a DVD with a CD reproduction and / or recording function can be used to record and reproduce DVD information and to irradiate a laser beam on the CD. Thus, a DVD that can perform label printing is assumed.

The DVD 50 shown in FIG. 1 has a thickness T of 1.2 mm, a substrate 51, a recording dye film 52 serving as a recording surface (information recording layer) of electronic information, a color filter (dichroic reflective film) 53, A visible light characteristic changing layer 55 to be a label surface (label layer) and a substrate 54 are sequentially stacked. Note that the color filter 5 is interposed between the color filter 53 and the visible light characteristic changing layer 55.
3 and a transparent intermediate layer 56 made of an adhesive or the like for bonding the visible light characteristic changing layer 55 to each other. FIG. 1 schematically shows the structure of the DVD 50, and the shape, dimension ratio, etc. of each layer are not as shown in this figure.

Among these layers, a predetermined pitch (track pitch = approximately 0.2 mm) is formed on the recording dye film 52.
74 μm) and a groove 52 a is formed in a spiral shape. When recording electronic information on the DVD 50, the laser beam is controlled (focus control) so that the laser beam is focused on the groove 52 a. Control (tracking control) is performed so that the laser beam is irradiated along the groove 52a, and pits corresponding to the recording data length are formed on the groove 52a.

Similarly, when reproducing information recorded on the DVD 50, the groove 52 is also reproduced.
The laser beam is controlled (focus control) so as to be focused on a, and the laser beam is controlled to be irradiated (tracking control) along the groove 52a.
At this time, the reflected signal of the laser beam reflected from the DVD 50 is demodulated to reproduce the recorded electronic information.

  The substrates 51 and 54 are made of, for example, polycarbonate resin.

The color filter 53 is composed of a dichroic reflective film formed of a dielectric film such as Zns, SiO2, or SiN or a laminated film thereof. The color filter 53 is preferably formed of a laminated film because the desired dichroism can be made larger than that of a single layer film.

The color filter 53 is not limited to the dichroic reflective film made of a dielectric film, but the following chemical formula
) May be composed of a dye such as cyanine dye NK-67 (manufactured by Nippon Photosensitivity Laboratories).

FIG. 2 shows the absorbance and refractive index of the cyanine dye as the optical characteristics of the cyanine dye as described above.

Referring to FIG. 2, the cyanine dye as described above has a maximum absorbance in the vicinity of a wavelength of 550 nm. And in the area | region of 650 nm vicinity which the said absorbance begins to fall, the refractive index has shown the maximum value. The maximum value of the refractive index of this cyanine dye is about 3.0. Accordingly, the color filter 53 is optimized for the film thickness and is made thin, so that the wavelength 650 is reduced.
A high reflectance can be exhibited in the vicinity of nm. In addition, since the cyanine dye hardly absorbs light in the vicinity of 780 nm, which is the wavelength of light used when reproducing information in a CD player, the color filter 53 exhibits high transmittance.

In the present embodiment, the layer constituting the color filter 53 has at least a band used for DVD recording (630 nm to 690 nm band) and a band used for CD reproduction (770 nm to 800 nm band). It is constituted by a layer having a higher reflectance. Note that the layers constituting the color filter 53 have a refractive index of a band used for DVD recording of 30 in the band.
It is preferable that the layer has a value that gives a reflectance of at least%, and is configured by a layer that has a transmittance of 90% or more in a band used for CD reproduction.

In the DVD 50 according to the present embodiment, the visible light characteristic changing layer 55 serving as a label surface is locally discolored only by being irradiated with light of a predetermined band (for example, infrared light having a wavelength of 780 nm). (Or deformed) material, for example, a polymer film.
As a polymer film, for example, a color change (for example, from white to black, or from transparent to black, such as a photosensitive material or a heat-sensitive material), by applying light or heat. The characteristics of visible light from the substrate 54 at the irradiated position are irradiated with a focused laser beam having a predetermined power or higher, such as a layer of a material (photosensitive layer, heat-sensitive layer, etc.) A layer made of a material that changes. As the visible light characteristic mentioned here, hue, lightness, and saturation, light absorption characteristic, reflectance, transmittance, light scattering, and the like of a visually recognized color can be considered.

Further, in the case of a conventional optical disc having a visible light characteristic change layer, a groove for guiding light in a predetermined band to be irradiated (for example, infrared light having a wavelength of 780 nm) is formed in the visible light characteristic change layer. However, it is not necessary to form such a groove in the visible light characteristic changing layer 55. Accordingly, the manufacturing process for forming the groove in the visible light characteristic change layer and the mold used in the process are not required, so that the manufacturing cost of the DVD 50 is reduced as compared with the conventional one.

As long as the DVD 50 is manufactured so as to be provided with each layer as described above, the manufacturing method does not matter. For example, the recording dye film 52 and the color filter 53 deposited on the substrate 51, and the substrate 54 are used. It is manufactured by adhering the layer on which the visible light characteristic changing layer 55 is deposited on the color filter 53 with an adhesive or the like constituting the transparent intermediate layer 56 with the visible light characteristic changing layer 55 facing the color filter 53 side. Can do. The transparent intermediate layer 56 is preferably transparent.

Next, an optical disk apparatus capable of recording electronic information and visible information (label printing) on the above-described DVD 50 will be described. FIG. 3 is a block diagram showing a configuration of the optical disc apparatus according to the present embodiment. An optical disc apparatus 100 shown in FIG. 3 is an optical disc apparatus that performs reproduction and recording of a DVD with a CD reproduction and / or recording function. Here, a DVD 50 is set as an optical disc to be recorded and reproduced.

As shown in FIG. 3, the optical disc apparatus 100 is connected to a personal computer (PC) 110 serving as a back end, and includes an optical pickup 10, a control unit 11, and a spindle motor 24. The control unit 11 includes an analog front end 12, a digital front end 13, and a buffer memory 14.

The analog front end 12 includes a reproduction signal processing unit 15, a servo processing unit 16, a power detection unit 17, and digital / analog (D / A) conversion units 18 and 19, and the digital front end 13 includes a CPU (Central Processing Unit). ) 20, a recording data processing unit 21, a label recording data processing unit 22, and a formatter 23.

The spindle motor 24 is a motor for rotationally driving the DVD 50 to be recorded and reproduced, and the number of rotations is controlled by a motor drive circuit (not shown). The motor drive circuit is supplied with a rotation instruction signal from the control unit 11 and a pulse signal having a frequency corresponding to the rotation speed of the spindle motor 24 fed back from the spindle motor 24 or a sensor provided in the spindle motor 24. The rotation control of the spindle motor 24 is performed based on these supplied signals. The spindle motor 24 can be rotated at a constant angular velocity (CAV method: Constant Angular Velocity) or at a constant recording linear velocity (CLV method: Constant Linear Velocity). Any of these may be used.

The optical pickup 10 is a unit that irradiates the laser beam L1 and L2 to the DVD 50 that is rotationally driven by the spindle motor 24, and a laser diode (LD) 37a that emits the laser beam L1 and a laser that emits the laser beam L2. Diode (LD)
37b, a laser diode driver (LDD) 25 for driving the LD 37a, and an LD 37
and a laser diode driver (LDD) 26 for driving b. Here, the laser beam L1 is red light having a wavelength of 660 nm used for DVD reproduction or recording,
The laser beam L2 has a wavelength 78 used for CD reproduction or recording and label printing.
It is 0 nm infrared light.

The optical pickup 10 can be moved in the radial direction of the set DVD 50 by an optical pickup moving unit (not shown) driven in accordance with the control of the control unit 11. That is, when the spindle motor 24 rotates the DVD 50 and the optical pickup moving unit moves the optical pickup 10 in the radial direction of the DVD 50, the irradiation positions of the laser beams L1 and L2 irradiated from the optical pickup 10 are set to the DVD 50. It can be moved to various positions.

The CPU 20 has firmware (not shown) stored in a ROM (Read Only Memory) (
Each part of the optical disk 100 is controlled in accordance with a program, and various processes for reproducing or recording on the DVD 50 and various processes for label printing are centrally controlled.

In the buffer memory 14, video / audio data which is electronic information to be recorded on the DVD 50, D
Image data, which is visible information to be recorded on the VD 50, is transmitted from the back end PC 110 and stored. This image data is data for forming an image on the surface of a disk-shaped optical disc, and is obtained by converting the bitmap data of the image formed on the label surface of the optical disc into polar coordinate format data. This is data in which information indicating the degree of gradation (shading) of a plurality of coordinate points on a large number of concentric circles centered on the center point is described.

Based on the video / audio data stored in the buffer memory 14, the control unit 11 performs the LD 37a.
The laser beam L1 is emitted from the laser beam L1, and the laser beam L2 is controlled to be emitted from the LD 37b based on the image data stored in the buffer memory 14.

Specifically, the formatter 23 performs predetermined signal processing on the video / audio data stored in the buffer memory 14 while using the buffer memory 14 as a work area under the control of the CPU 20, and records it on the recording surface of the DVD 50. Recording data matching the format to be generated is generated and output to the recording data processing unit 21.

The recording data processing unit 21 generates a recording data signal to be recorded on the recording surface of the DVD 50 based on the recording data from the formatter 23 under the control of the CPU 20 and supplies the recording data signal to the LDD 25 of the optical pickup 10. Then, the LDD 25 is driven based on the recording data signal, and the recording surface of the DVD 50 is irradiated with the laser beam L1 to record video / audio data as electronic information.

Further, the formatter 23 performs predetermined signal processing on the image data and the like stored in the buffer memory 14 while using the buffer memory 14 as a work area under the control of the CPU 20, and records the data on the label surface of the DVD 50. The matched label recording data is generated and output to the label recording data processing unit 21.

The label recording data processing unit 22 then formats the formatter 2 according to the control of the CPU 20.
3, a label recording data signal to be recorded on the label surface of the DVD 50 is generated based on the label recording data from 3 and supplied to the LDD 26 of the optical pickup 10. And LDD2
6 is driven based on this label recording data signal, and the laser beam L2 is irradiated onto the label surface of the DVD 50 to record image data as visible information.

Next, the configuration of the optical pickup 10 will be described in detail with reference to FIG. As shown in FIG. 4, the optical pickup 10 includes the above-described LD 37 a, LD 37 b, LDD 25, LDD 26, and optical for condensing the laser beams L 1 and L 2 onto the DVD 50 (the recording dye film 52 and the visible light characteristic changing layer 55). Laser beams L1 and L emitted from the system 40 and the LDs 37a and 37b
A front monitor 28 that receives a part of 2 and monitors the intensity thereof; a light receiving unit 36 that receives reflected light from the DVD 50 and converts the received light signal, which is a received light signal, into an electrical signal;
And a temperature sensor 27 for detecting the temperature of the optical pickup 10.

The LDD 25 outputs a driving current based on the recording data signal from the recording data processing unit 21 of the control unit 11 to drive the LD 37a, and the LDD 26 is based on the label recording data signal from the label recording data processing unit 22 of the control unit 11. A drive current is output to drive the LD 37b.

When a drive current is supplied from the LDD 25, the LD 37a emits a laser beam L1 having an intensity corresponding to the drive current. The magnitude of this drive current is calculated from the CPU 20 shown in FIG.
This is determined based on an intensity instruction signal which is supplied to the A conversion unit 18 and converted into an analog signal by the D / A conversion unit 18 and set in the LDD 25. Here, the CPU 20 uses the monitor voltage supplied from the front monitor 28 to perform feedback control for controlling the laser beam L1 having the target intensity to be emitted from the LD 37a.

A part of the laser beam L1 emitted from the LD 37a is incident on the front monitor 28 after being split by the rising mirror 29, and the front monitor 28 enters the incident laser beam L1.
The monitor voltage corresponding to the amount of light is output. The monitor voltage from the front monitor 28 is digitally converted by the power detection unit 17 and applied to the CPU 20, and the CPU 20 compares the monitor voltage value with a preset target value of the emission intensity of the laser beam L1. Then, an intensity instruction signal is output to the D / A converter 18 so that the laser beam L1 having a value that matches the target value of the emission intensity of the laser beam L1 is emitted from the LD 37a.

Further, the target value of the light emission intensity of the laser beam L1 set in the LDD 25 takes two values, that is, the reproduction intensity (second intensity) and the recording intensity (first intensity). Reproduction strength is electronic information (pit)
Read intensity and the intensity of the reflected light required for focus control and tracking control by the servo processing unit 16 to be described later.
Electronic information recorded on the recording dye film 52 of D50 can be read, but electronic information cannot be recorded on the recording dye film 52. On the other hand, the recording intensity is the recording dye film 52.
The light emission intensity at which electronic information is written.

The laser beam L1 emitted from the LD 37a is separated into a main beam and two sub beams (preceding beam and trailing beam) by the diffraction grating 38a, and these three laser beams L are separated.
Reference numeral 1 denotes polarization beam splitters 39a and 39b, a raising mirror 29, and a collimator lens 30.
Then, the light passes through the quarter-wave plate 31 and the objective lens 32 and is condensed on the recording dye film 52 which is the recording surface of the DVD 50 as shown in FIG.

Since this laser beam L1 is reflected by the color filter 53 of the DVD 50, the laser beam L1 irradiated for reproducing or recording electronic information on the recording dye film 52 is
It is possible to avoid adverse effects such as forming an unintended image as image formation on the visible light characteristic changing layer 55.

The three laser beams L1 reflected by the color filter 53 of the DVD 50 are again
It passes through the objective lens 32, the quarter-wave plate 31, the collimator lens 30, the rising mirror 29, and the polarization beam splitter 39 b, is reflected by the deflection beam splitter 39 a, and enters the light receiving unit 36 through the cylindrical lens 33. It has become.

Then, the light receiving unit 36 converts the received light signal, which is a received optical signal, into an electrical signal, and supplies it to the reproduction signal processing unit 15 and the servo processing unit 16 in the analog front end 12 shown in FIG. The reproduction signal processing unit 15 demodulates the modulated electric signal read from the recording dye film 52 from the light receiving unit 36 into various data such as music data, and the CPU 20 and the buffer memory 14.
To the PC 110 as a back end. Then, the demodulated data is reproduced by various reproducing means (not shown) of the PC 110.

Further, the servo processing unit 16 includes the positional information of the groove 52a used for tracking control included in the light reception signal from the light receiving unit 36, and the recording dye film 5 used for focus control.
The information (focus information) relating to the focus of the laser beam L1 focused on 2 is supplied. Details of the tracking control and focus control will be described later.

On the other hand, when a drive current is supplied from the LDD 26, the LD 37b emits a laser beam L2 having an intensity corresponding to the drive current. The magnitude of the drive current is determined based on an intensity instruction signal that is given from the CPU 20 to the D / A converter 19 shown in FIG. 3 and converted into an analog signal by the D / A converter 19 and set in the LDD 26. Here, the CPU 20 uses the monitor voltage supplied from the front monitor 28 to perform feedback control for controlling the laser beam L2 having the target intensity to be emitted from the LD 37b.

A part of the laser beam L2 emitted from the LD 37b is split by the rising mirror 29 and enters the front monitor 28, and the front monitor 28 enters the incident laser beam L2.
The monitor voltage corresponding to the amount of light is output. The monitor voltage from the front monitor 28 is digitally converted by the power detection unit 17 and applied to the CPU 20, and the CPU 20 compares the monitor voltage value with a preset target value of the emission intensity of the laser beam L2. Then, an intensity instruction signal is output to the D / A converter 19 so that the laser beam L2 having an intensity that matches the target value of the emission intensity of the laser beam L2 is emitted from the LD 37b.

Further, the target value of the light emission intensity of the laser beam L2 set in the LDD 26 takes two values of the space intensity and the mark intensity. The space intensity means the light emission intensity that does not change (deform) the visible light characteristic changing layer 55 of the DVD 50, and the mark intensity means the color change (deformation) of the visible light characteristic changing layer 55.
The intensity of the emitted light.

The laser beam L2 emitted from the LD 37b is separated into a main beam and two sub beams (preceding beam and trailing beam) by the diffraction grating 38b, and these three laser beams L are separated.
2 is a polarizing beam splitter 39b, a raising mirror 29, a collimator lens 30, and 1/4.
As shown in FIG. 5, the light is condensed on the visible light characteristic changing layer 55 that is the label surface of the DVD 50 through the wave plate 31 and the objective lens 32.

The objective lens 32 includes a focus actuator 34 and a tracking actuator 3.
5 and is movable in the optical axis direction of the laser beams L1 and L2 and the radial direction of the DVD 50. Each of the focus actuator 34 and the tracking actuator 35 includes a focus error (FE) supplied from the servo processing unit 16 of the control unit 11.
) The objective lens 32 is moved in the optical axis direction and the radial direction according to the signal and the tracking error (TE) signal.

The servo processing unit 16 generates the FE signal and the TE based on the light receiving signal supplied from the light receiving unit 36.
Signals are generated and given to the focus actuator 34 and the tracking actuator 35 to perform focus control and tracking control.

The above-mentioned three laser beams L1 emitted from the LD 37a and applied to the DVD 50 are:
When the spot center of the main beam is located at the center of one groove 52a of the DVD 50,
The positional relationship is such that the spot of one sub beam is applied to the inner surface of the groove 52a and the spot of the other sub beam is applied to the outer surface of the groove 52a.

For this reason, the servo processing unit 16 calculates the difference in the intensity of the reflected light of the two sub beams detected by the light receiving unit 36 using the light reception signal given from the light receiving unit 36, thereby targeting the main beam as the target. It is possible to know how much the inner side / outside side is displaced from the center of the groove 52a, that is, the tracking error amount. The servo processing unit 16
By generating a TE signal for making the tracking error amount zero and controlling the tracking actuator 35 with the TE signal, the main beam can be accurately centered on the target groove 52a even if the DVD 50 rotates eccentrically. It can be traced (tracking control). This tracking control may be performed by a phase difference method (one beam tracking method) in addition to the above-described three beam method.

As shown in FIG. 6, the light receiving unit 36 actually has four detection areas, a, b,
The main beam of the laser beam L1 that is divided into c and d and is focused on the light receiving unit 36 becomes a vertical ellipse A when the objective lens 32 is close to the DVD 50 by the cylindrical lens 33, and in a far state. If there is, it becomes a horizontal ellipse B, and if it is in focus, it becomes a circle C.

For this reason, the received light intensity of the four areas a, b, c, and d is calculated by an arithmetic expression of (a + c) − (b + d), and the objective lens 32 is in focus with respect to the DVD 50 from the obtained calculation result. It is possible to know how much is shifted to the near / far side, that is, the focus error amount. The servo processing unit 16 generates an FE signal for setting the focus error amount to a predetermined value, and controls the tracking actuator 35 with the FE signal. Main beam focus on DVD
50 can be accurately adjusted (focus control).

In this way, by performing tracking control and focus control by the reflected light of the laser beam L1, when the laser beam L1 and the laser beam L2 are emitted simultaneously, the laser beam L2 collected by the same optical system is collected. Also, tracking control and focus control are performed.

In other words, the laser beam L2 irradiated on the visible light characteristic changing layer 55 of the DVD 50 is changed by the objective lens 32 based on the reflected light of the laser beam L1 irradiated simultaneously.
Since the focus control and the tracking control are performed by the above, the alignment and the focus adjustment are accurately performed on the coordinate point where the image data on the visible light characteristic change layer 55 is to be formed.

That is, the visible light characteristic changing layer 55 of the DVD 50 is not provided with a groove for focus control and tracking control, and the laser beam L2 irradiated for image formation is focused based on the reflected light. Without performing control and tracking control, a desired position on the visible light characteristic change layer 55 is accurately irradiated with the laser beam L2. Thereby, a desired image can be accurately formed on the label surface of the DVD 50.

The objective lens 32 is configured such that the NA (Numerical Aperture) for each wavelength of the laser beam varies depending on the wavelength of the laser beam incident on the objective lens 32, and thereby the laser in the DVD 50. The spot positions and spot diameters of the beams L1 and L2 (diameters that are 1 / e ² of the center intensity at the spot of the laser beam) are different.

FIG. 7 is a diagram conceptually showing how video / audio data and image data are recorded on the DVD 50. As shown in FIG. 7, the spot diameter of the laser beam L2 is much larger than the spot diameter of the laser beam L1. This is because electronic information (pits) recorded on the recording surface of the DVD 50 by the irradiation of the laser beam L1 is 0.7 μm on the recording dye layer 52.
Visible information (images etc.) recorded on the label surface of the DVD 50 by irradiation with the laser beam L2 while high density recording with minute pits of about 0.4 μm is required in the groove 52a formed with a pitch of about m. ) Is visual information, and dot (point) information of about 100 μm square is sufficient.

For this reason, in order to record visible information of a certain point (about 100 μm square), the groove 5
When the laser beam L2 is irradiated at a track pitch of 2a, the regions irradiated with the laser beam L2 overlap as shown in FIG. If it does so, there exists a possibility that the thermal storage amount of the part irradiated with the laser beam L2 of the visible light characteristic change layer 55 may become large, and the part may deteriorate. Also, due to temperature rise, recorded electronic information (pits) and visible information (
The shape and size of the image may be different from the shape and size that should be recorded.

In order to prevent this, the laser beam L2 is not irradiated with the track pitch of the groove 52a, but is irradiated every several tracks as shown in FIG. 8B. This can also be said to have thinned out the emission time of the laser beam L2. This thinning control is possible by adjusting the label recording data signal applied to the LDD 26 by the label recording data processing unit 22. By doing so, the regions irradiated with the laser beam L2 do not overlap, so the amount of heat stored in the portion of the visible light characteristic change layer 55 irradiated with the laser beam L2 does not increase, and the visible light characteristics Deterioration of the change layer 55 can be prevented. Further, since the temperature rise is suppressed, it is possible to prevent the shape and size of the recorded electronic information (pits) and visible information (images) from being different from the shape and size to be originally recorded. it can.

Further, when the laser beam L1 and the laser beam L2 are emitted at the same time, the temperature rise of the optical pickup 10 is larger than that when the respective laser beams are separately irradiated in a time division manner. In addition, since the emission time of the laser beam L2 is reduced, the temperature rise of the optical pickup 10 is also suppressed, and the life of the optical pickup 10 is not shortened or is not thermally destroyed.

Further, if the thinning rate at which the emission time of the laser beam L2 is thinned is determined based on the gradation (shading) of the points to be recorded, for example, the darkness as shown in FIG. Certain visible information can be recorded.

Further, as shown in FIG. 8C, the irradiation of the laser beam L2 may be thinned out in the traveling direction of the laser beam. Even in this case, since the region irradiated with the laser beam L2 overlaps, the amount of heat stored in the portion of the visible light characteristic change layer 55 irradiated with the laser beam L2 does not increase, and the visible light characteristic change occurs. Deterioration of the layer 55 can be prevented. Further, it is possible to record dark and light visible information, and to suppress the temperature rise of the optical pickup 10.

Further, the thinning of the irradiation time of the laser beam L2 may be performed by combining thinning by the above-described two methods, that is, thinning in the traveling direction of the laser beam L2 and thinning in the track direction.

Returning to FIG. 3 and FIG. 4, the temperature sensor 27 detects the temperature T of the optical pickup 10, and gives temperature data indicating the detected temperature T to the control unit 11. Then, the CPU 20 in the control unit 11 is preset with the temperature T of the optical pickup 10 using the temperature data given from the temperature sensor 27 when the electronic information and the visible information are recorded on the DVD 50. The upper limit temperature Tth is compared, and the laser beam L1 irradiated to the DVD 50 based on the comparison result
, L2 emission is controlled. The upper limit temperature Tth is set to a temperature at which the life of the optical pickup 10 is not shortened or is not thermally destroyed.

Next, the recording operation of the electronic information and the visible information on the DVD 50 of the optical disc apparatus 100 having such a configuration will be described with reference to the flowchart shown in FIG.

First, the DVD 50 is set on the optical disc apparatus 100, and when the user operates the PC 110, an instruction to start recording electronic information and visible information on the set DVD 50 is issued to the PC 1.
10 to the control unit 11. At this time, for example, video / audio data which is electronic information to be recorded on the recording dye layer 52 of the DVD 50 and image data of an image which is visible information to be recorded on the visible light characteristic change layer 55 are given from the PC 110 to the control unit 11. The CPU 20 accumulates the given data in the buffer memory 14 (step S1).

Next, the CPU 20 controls a motor drive circuit (not shown) to rotate the DVD 50 at a predetermined speed by the spindle motor 24 and controls an optical pickup moving unit (not shown) to position the optical pickup 10 (a radial position relative to the DVD 50). ) Is moved to the initial position on the innermost peripheral side in the radial direction of the DVD 50 (step S2).

Next, in order to turn on the servo control, the CPU 20 reads the laser beam L having a reproduction intensity.
The LDD 11 is controlled so that 1 is irradiated onto the DVD 50 (step S3). That is, after that, based on the received light signal from the light receiving unit 36 which is a signal of reflected light from the color filter 53 of the DVD 50 of the irradiated laser beam L1, the above-described focus control and servo control by the servo processing unit 16 are performed. Tracking control is performed. When necessary for tracking control, the CPU 20 controls the optical pickup moving unit (not shown) to control the optical pickup 1.
0 is moved in the radial direction of the DVD 50.

Next, the CPU 20 compares the temperature T of the optical pickup 10 with the preset upper limit temperature Tth using the temperature data given from the temperature sensor 27 (step S4),
When it is determined that the temperature T is lower than the upper limit temperature T (T <Tth) (No in step S4), the recording data signal obtained by converting the video / audio data stored in the buffer memory is LDD2.
5, the formatter 23 and the recording data processing unit 21 are controlled. Thereby, the emission intensity of the laser beam L1 emitted from the LD 37a is switched between the reproduction intensity and the recording intensity based on the recording data signal, and the video / audio data is recorded on the recording dye film 52.

At the same time, the CPU 20 controls the formatter 23 and the label recording data processing unit 22 so that the label recording data signal obtained by converting the image data stored in the buffer memory is supplied to the LDD 26. Thereby, the emission intensity of the laser beam L2 irradiated from the LD 37b is switched between the space intensity and the mark intensity based on the label recording data signal, and image data is recorded in the visible light characteristic changing layer 55 (step S).
5).

On the other hand, when it is determined that the temperature T is higher than the upper limit temperature T (T> Tth) (Yes in step S4), the CPU 20 also converts the image data stored in the buffer memory as in step S5. The formatter 23 and the label recording data processing unit 22 are controlled so that the recording data signal is given to the LDD 26, whereby the emission intensity of the laser beam L2 emitted from the LD 37b is determined based on the label recording data signal. The image data is recorded in the visible light characteristic changing layer 55.

However, unlike the case of step S5, in this case (step S6), the CPU 20
A recording data signal obtained by converting the audio / video data stored in the buffer memory is an LDD 25.
The formatter 23 and the recording data processing unit 21 are controlled so as not to be given. Thereby, the emission intensity of the laser beam L1 emitted from the LD 37a is not switched between the reproduction intensity and the recording intensity based on the recording data signal, and the DVD 50 is irradiated with the laser beam L1 having the reproduction intensity necessary for servo control. Will continue to be.

By doing in this way, the temperature rise of the optical pick-up 10 can be suppressed.
That is, the amount of heat generated by the optical pickup 10 by emitting the laser beam L1 having the reproduction intensity is smaller than the amount of heat generated by the optical pickup 10 by emitting the laser beam L1 having the recording intensity. By controlling so as not to emit light, an increase in temperature of the optical pickup 10 can be suppressed.

Then, after step S5 and step S6, the CPU 20 determines whether or not recording processing has been performed by irradiating the laser beams L1 and L2 on all of the video / audio data and image data stored in the buffer memory 14, that is, recording is performed. Whether all the video / audio data to be recorded has been recorded and all the image data to be recorded has been recorded is determined (step S7).
When it is determined that the recording has not been completed yet (No in Step S7), the process returns to Step S4, and the recording of the video / audio data and the recording of the image data are continued while monitoring the temperature T of the optical pickup 10.

On the other hand, when it is determined that all of the video / audio data and image data to be recorded have been recorded (Yes in step S7), an irradiation stop instruction signal is given to the LDDs 25 and 26, and the laser beams L1 and L2 from the optical pickup 10 are transmitted. The irradiation is stopped and the motor drive circuit is controlled to stop the rotation of the DVD 50 by the spindle motor 24 (step S8). This completes the recording operation of the video / audio data and the image data.

As described above, according to the optical disc apparatus 100 of the present embodiment, the user can
Once the recording surface of 50 is set in the optical disc device 100 so as to face the optical pickup 10, not only the recording dye film 52 which is the recording surface of the DVD 50 is recorded but also the visible light which is the label surface. A visible image can be formed on the characteristic change layer 55. For this reason, the user does not need to prepare a dedicated printer device, and the D in which electronic information is recorded.
A label sheet printed separately on the VD or a DVD for label printing
There is no need to perform complicated work such as turning over 50 and setting it again.

In addition, since the optical disc apparatus 100 according to the present embodiment can perform recording of electronic information on the DVD 50 and label printing at the same time, the time required for performing information recording and label printing on the DVD 50 can be shortened. Can do. That is, a visible image can be efficiently printed on the label surface of the optical disk.

Further, when recording of electronic information on the DVD 50 and label printing are simultaneously performed, the laser beams L1 and L2 are emitted simultaneously. Even in such a case, the laser beam L2 is emitted. Since the emission time of the optical pickup 10 and the temperature increase of the DVD 50 are suppressed, the DV that is irradiated with the optical pickup 10 and the laser beams L1 and L2 is suppressed.
Overheating of D50 can be prevented.

Further, in the DVD 50 described in this embodiment described above, a light source for DVD (630 nm)
Electronic information is reproduced or recorded with a light source of ˜690 nm band, and a light source for CD (770 nm˜8)
In the embodiment, the label printing is performed with the light source of 00 nm band), but the present invention is an example in which the label printing is performed with the light source for DVD and the electronic information is reproduced or recorded with the light source for CD. It is possible to apply to other examples. Specifically, for example, information is recorded on an optical disk using a laser light source of 405 nm band which is a light source of next-generation DVD, and DVD
The present invention can also be applied to an example in which label printing is performed with a light source.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a sectional side view which shows the structure of DVD which is an example of the optical disk which the optical disk apparatus of one Embodiment of this invention makes object. It is a figure which shows the light absorbency and refractive index of the cyanine dye which can be made into the material of a color filter in DVD shown in FIG. It is a block diagram which shows the structure of the optical disk apparatus of one Embodiment of this invention. It is a figure which shows the structure of the optical pick-up shown in FIG. It is a figure for demonstrating the optical path of the laser beam radiate | emitted from the optical pick-up shown in FIG. It is a figure which shows the structure of the light-receiving part shown in FIG. FIG. 4 is a diagram conceptually showing a state in which video / audio data and image data are recorded on a DVD by the optical disc apparatus shown in FIG. 3. It is a figure which shows the example of laser beam irradiation by the optical disk apparatus shown in FIG. It is a figure which shows the label surface of DVD by which label printing was carried out by the optical disk apparatus shown in FIG. 4 is a flowchart for explaining an electronic information recording operation and a label printing operation on a DVD by the optical disc apparatus shown in FIG. 3.

Explanation of symbols

10 Optical Pickup 11 Control Unit (Control Unit)
12 Analog Front End 13 Digital Front End 14 Buffer Memory 15 Playback Signal Processing Unit 16 Servo Processing Unit (Servo Processing Means)
17 Power detection unit 18, 19 Digital / analog (D / A) conversion unit 20 CPU
21 recording data processing unit 22 label recording data processing unit 23 formatter 24 spindle motor 25 laser diode driver (LDD, first laser diode driver, intensity switching means)
26 Laser diode driver (LDD, second laser diode driver)
27 Temperature sensor (temperature detection means)
28 Front monitor 29 Raising mirror 30 Collimator lens 31 1/4 wavelength plate 32 Objective lens 33 Cylindrical lens 34 Focus actuator 35 Tracking actuator 36 Light receiving part 37a Laser diode (LD, first laser diode)
37b Laser diode (LD, second laser diode)
38a, 38b Diffraction gratings 39a, 39b Polarizing beam splitter 40 Optical system 50 DVD (optical disk)
51, 54 Substrate 52 Dye recording film (information recording layer)
52a groove 53 color filter (dichroic reflective film)
55 Visible light property changing layer (label layer)
56 Transparent intermediate layer 100 Optical disc device 110 Personal computer (PC)
L1 laser beam (first laser beam)
L2 laser beam (second laser beam)

Claims (1)

An information recording layer in which a groove is formed and electronic information is reproduced or recorded by irradiation with the first laser beam, and a second laser beam with a wavelength band different from that of the first laser beam is irradiated. A label layer on which visible information is recorded, and two colors which are provided between the information recording layer and the label layer and have a higher reflectance for the first laser beam than the reflectance for the second laser beam. First and second optical discs having a reflective film
An optical disc apparatus for performing reproduction or recording of electronic information and recording of visible information by irradiating the laser beam from the information recording layer side,
A first laser diode that emits a first laser beam; an intensity of the first laser beam that drives and drives the first laser diode; and a first intensity that records electronic information on the information recording layer; A first laser diode driver that switches to a second intensity that is weaker than a first intensity and that is used to reproduce electronic information recorded in the information recording layer; and a second laser diode that emits a second laser beam A second laser diode driver for driving the second laser diode, an objective lens for condensing the first laser beam on the information recording layer and condensing the second laser beam on the label layer, A tracking actuator that drives the objective lens in the radial direction of the optical disc, and a focus actuator that drives the objective lens in the optical axis direction. And Yueta, an optical pickup having a first laser beam of said dichroic reflecting film receives the light reflected from the light-receiving unit that outputs a light reception signal based on the received reflected light,
Based on the groove position information included in the light reception signal, the tracking actuator is driven to perform tracking control of the laser beam applied to the optical disc, and the first information recording layer included in the light reception signal is controlled. Servo processing means for controlling the focus of the laser beam irradiated on the optical disk by driving the focus actuator based on the focus information of the laser beam;
Temperature detecting means for detecting the temperature of the optical pickup;
When recording electronic information and visible information on the optical disc, the first laser diode driver is driven, and the intensity of the first laser beam emitted based on the electronic information to be recorded is the first intensity and the first intensity. The intensity of the first laser beam emitted is changed to the second intensity when the temperature detected by the temperature detecting means is higher than a predetermined temperature.
The first laser diode driver is controlled so as to have the intensity of the second, the second laser diode driver is driven based on the visible information to be recorded, and the gradation indicating the density of the visible information contained in the visible information to be recorded The decimation rate is determined based on the second decimation rate
Control means for performing thinning-out control of the laser beam emission time;
Optical disk apparatus characterized by comprising a.

Images