JP2006134423A - Optical disk apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk apparatus capable of forming an accurate and clear visible image at high speed on a label surface by irradiating an optical disk with a laser beam without turning over the optical disk. <P>SOLUTION: The optical disk apparatus is provided with: an optical pickup 10 having an objective lens 32 condensing a laser beam L1 and a laser beam L2 on a recording dye film 52 and a visible light characteristic change layer 55 of a DVD 50, respectively, and a color filter aperture 41 reducing an NA (numerical aperture) of the objective lens 32 for the laser beam L2 and outputting a light receiving signal based on reflected light of the laser beam L1, a servo circuit 15 performing focus control and tracking control of the laser beam based on the light receiving signal; and a control part 17 controlling the optical pickup 10 so that the laser beam L1 is emitted therefrom and the laser beam L2 is emitted therefrom based on the image data to be printed when label printing is performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an optical disk device, and more particularly to an optical disk device capable of reproducing or recording information and forming a visible image by irradiating the optical disk with a laser beam.

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

When 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. Therefore, the user can use a dedicated printer device to indicate characters recorded on the optical disc, etc. (For example, a song title, a movie title, etc.) are printed on a circular sheet, and this sheet is attached to the surface opposite to the recording surface of the optical disc (hereinafter referred to as a label surface).

However, in this method, the user needs to prepare a dedicated printer device,
In addition, it is necessary to perform complicated operations such as printing a sheet with the dedicated printer device and attaching the printed sheet to 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 forming (printing) a visible image (for example, a character indicating a song title, a movie title, etc.) to be recognized automatically has been provided (for example, Patent Document 1, Patent). Reference 2).

Further, the test laser irradiation is performed on the area of the optical disk having a high reflectivity, the focus control content is determined based on the focus control content executed at that time, and stored in the memory. Based on the stored focus control content There is also an optical disc apparatus that performs focus control (see, for example, Patent Document 3).

An information recording carrier comprising a support having a fine pattern composed of a continuous groove in which grooves and lands are alternately formed, and a recording layer formed on the fine pattern for recording information. There is an information recording carrier in which the fine pattern is formed based on the wavelength of reproducing light for reproducing the recording layer and the numerical aperture of the objective lens (see, for example, Patent Document 4).
JP 2003-203348 A Japanese Patent Laid-Open No. 2004-5846 JP 2003-242669 A JP 2004-46910 A

However, even if the conventional optical disc recording apparatus described in Patent Document 1 is used, the user still needs to perform complicated work. That is, when recording information, the user attaches the optical disk to the apparatus so that the recording surface side of the optical disk is irradiated with a laser beam, and when printing a visible image on the label surface of the optical disk, In order to irradiate the laser beam on the surface side, it is necessary to perform a complicated operation of turning the optical disc over and remounting it.

On the other hand, in the conventional optical disc recording apparatus described in Patent Document 2, information recording and visible image formation can be performed by irradiating laser light from one side of the optical disc, so that the optical disc is turned over and reattached during label printing. However, in order to perform focus control and tracking control of the laser light applied to the color changing layer in order to form a visible image, reflected light from the color changing layer is required. Therefore, if the discoloration efficiency of the color changing layer with respect to the irradiated laser light is increased in order to efficiently form a visible image, the reflected light from the color changing layer is reduced, so focus control and tracking of the laser light applied to the color changing layer is reduced. There is a problem that control cannot be performed and an accurate image cannot be formed.

In contrast, the conventional optical disk device described in Patent Document 3 can perform more accurate focus control even when laser light is irradiated to an area where the reflected light from the optical disk cannot be sufficiently obtained. However, the focus control according to the focus control content stored by the test laser irradiation cannot perform accurate focus control following the surface shake of the optical disc.

Further, in a conventional optical disc apparatus that performs label printing by irradiating a laser beam, an image is formed by irradiating the laser beam along a groove formed at a predetermined pitch on the label surface of the optical disc. When the diameter that is 1 / e ² of the center intensity at the spot of the laser beam is smaller than the pitch of the groove, there is a problem that the formed image becomes comb-like and cannot be printed clearly. Another problem is that it takes time to form an image.

On the other hand, Patent Documents 1 to 3 show a method of increasing the spot diameter of the laser light irradiated to the label surface by focus control. If the spot diameter of the laser light is increased by focus control, the label surface Therefore, there is a problem in that it is impossible to accurately perform focus control and tracking control and to form an accurate image.

The prior art described in Patent Document 4 is intended to prevent cross erase during information recording on the recording surface of the optical disc. This prior art is accurate and clear on the label surface of the optical disc. It is not applicable for printing images.

The present invention has been made to solve the above-described problems, and it is not necessary to perform the troublesome work of turning the optical disk upside down when performing label printing of the optical disk, and the optical disk is irradiated with a laser beam. It is an object of the present invention to provide an optical disc apparatus capable of forming an accurate and clear visible image on the label surface at high speed.

In order to achieve the above object, an invention according to claim 1 is directed to an information recording layer on which information is recorded by forming grooves at a predetermined pitch and irradiating the first laser beam, and the first laser beam. The reflectance of the first laser beam provided between the label layer on which a visible image is formed by irradiation with a second laser beam having a different wavelength band from the information recording layer and the label layer. Information recording and visibility can be performed by irradiating the optical disk having a dichroic reflecting film higher in reflectance than the second laser beam from the information recording layer side with the first and second laser beams. An optical disc apparatus for forming an image, wherein a first laser diode that emits a first laser beam and a first laser diode that drives the first laser diode
A laser diode driver, a second laser diode for emitting a second laser beam, a second laser diode driver for driving the second laser diode, and condensing the first laser beam on the information recording layer And an objective lens for condensing the second laser beam on the label layer, and having a wavelength selectivity and a diameter that is 1 / e ² of the center intensity at the spot of the second laser beam in the label layer. A color filter aperture that changes the numerical aperture of the objective lens for the second laser beam to be larger than the predetermined pitch of the groove, a tracking actuator that drives the objective lens in the radial direction of the optical disc, A focus actuator that drives the objective lens in the optical axis direction;
Position information of the groove included in the light receiving signal, and an optical pickup having a light receiving element that receives reflected light from the dichroic reflecting film of the first laser beam and outputs a light receiving signal based on the received reflected light The tracking actuator is driven based on the tracking control of the laser beam applied to the optical disc, and the focus actuator is controlled based on the focus information of the first laser beam in the information recording layer included in the light receiving signal. And a servo circuit for controlling the focus of the laser beam applied to the optical disc, and driving the first laser diode driver when forming a visible image on the optical disc, and image data of the visible image to be formed Control unit for driving second laser diode driver based on To provide an optical disk apparatus characterized by comprising a.

According to this configuration, when a visible image is formed on the optical disc, the control unit drives the first laser diode driver so that the first laser beam is irradiated from the first laser diode and passes through the objective lens. And condensed on the information recording layer of the optical disc. At this time,
Since the irradiated first laser beam is reflected by the dichroic reflecting film, the visible light characteristic changing layer is not affected.

At this time, the control unit drives the second laser diode driver based on the image data of the visible image to be formed, so that the second laser beam is irradiated from the second laser diode through the objective lens. Focused on the label layer of the optical disc. As a result, an image is formed on the label layer of the optical disc. At this time, the irradiated second laser beam passes through the dichroic reflection film and reaches the label layer.

At this time, the tracking actuator that drives the objective lens by the servo circuit 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. Is driven and tracking control of the laser beam irradiated onto the optical disk is performed. At the same time, the servo circuit drives the focus actuator that drives the objective lens based on the focus information of the first laser beam in the information recording layer of the optical disk included in the received light signal, and the focus of the laser beam irradiated onto the optical disk Control 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.

Further, at this time, the diameter that is 1 / e ² of the center intensity at the spot of the second laser beam in the label layer has wavelength selectivity and changes the numerical aperture of the objective lens for the second laser beam. The color filter aperture is larger than a predetermined pitch of the grooves formed on the information recording layer of the optical disc. The second laser beam applied to the label layer is
Since tracking is performed based on the groove formed in the information recording layer of the optical disk by the servo circuit, the irradiation pitch of the second laser beam in the radial direction of the optical disk is the lowest pitch of the predetermined pitch of the groove. Accordingly, since the diameter that becomes 1 / e ² of the center intensity at the spot of the second laser beam is larger than the lowest pitch of the irradiation pitch in the radial direction of the optical disc, an image formed by the irradiation of the second laser beam can be obtained. It can be continued in the radial direction of the optical disk. As a result, the image does not become comb-like, and a clear image can be printed on the label. In addition, an image can be formed at high speed.

According to the second aspect of the present invention, information is reproduced or recorded by irradiation with the first laser beam, and a visible image is formed by irradiation with a second laser beam having a wavelength band different from that of the first laser beam. An optical disc apparatus for reproducing or recording information and forming a visible image by irradiating the formed optical disc with first and second laser beams from the side of the optical disc where information is reproduced or recorded. A laser beam emitting section for emitting the first and second laser beams, an objective lens for condensing the emitted first and second laser beams on the optical disc, and the second laser beam. The numerical aperture of the objective lens is first
There is provided an optical disc apparatus comprising an optical pickup having a numerical aperture changing section for changing the numerical aperture of the laser beam to a value lower than the numerical aperture of the objective lens.

According to this configuration, by emitting the first laser beam from the optical pickup, the emitted first laser beam is focused on the optical disc, and information can be reproduced or recorded on the optical disc. It becomes. Further, by emitting the second laser beam from the optical pickup, the emitted second laser beam is focused on the optical disc,
A visible image can be formed on the optical disc.

Further, the numerical aperture changing unit causes the numerical aperture of the objective lens for the second laser beam to be lower than the numerical aperture of the objective lens for the first laser beam. The diameter that becomes 1 / e ² of the center intensity at the spot of the ^second laser beam is larger than the diameter that becomes 1 / e ² of the center intensity at the spot of the first laser beam focused on the optical disc. Become. Therefore, when a visible image is formed, an image can be formed at a high speed.

According to a third aspect of the present invention, in the second aspect of the present invention, the numerical aperture changing section is a liquid crystal filter or a color filter aperture having wavelength selectivity. In this way, the numerical aperture of the objective lens can be easily changed.

According to a fourth aspect of the present invention, there is provided an information recording layer on which information is recorded by forming grooves at a predetermined pitch and irradiating the first laser beam, and a second wavelength band different from the first laser beam. The laser beam is irradiated with a label layer on which a visible image is formed, and the reflectance of the first laser beam provided between the information recording layer and the label layer is second.
By irradiating an optical disc having a dichroic reflecting film having a higher reflectance than the laser beam of the first and second laser beams from the information recording layer side, information recording and visible image recording are performed. An optical disc apparatus that performs formation, wherein the first and second laser beams are emitted, the emitted first laser beam is condensed on the information recording layer, and the emitted second laser beam is The dichroic reflective film of the first laser beam is focused on the label layer so that a diameter which is 1 / e ² of the center intensity at the spot in the label layer is larger than the predetermined pitch of the groove. An optical pickup that receives reflected light from the light and outputs a received light signal based on the received reflected light, and operates the optical pickup based on positional information of the groove included in the received light signal. Tracking control of the laser beam irradiated to the optical disc is performed, and the optical disc is irradiated by operating the optical pickup based on the focus information of the first laser beam in the information recording layer included in the light reception signal. A servo circuit that performs focus control of a laser beam, and a second laser based on image data of the visible image to be formed while emitting a first laser beam from the optical pickup when forming a visible image on the optical disc Provided is an optical disc apparatus comprising a control unit that controls to emit a beam.

According to this configuration, when a visible image is formed on the optical disc, the control unit emits the first laser beam from the optical pickup, and the emitted first laser beam is transmitted to the information recording layer of the optical disc by the optical pickup. It is focused on. At this time, the irradiated first laser beam is reflected by the dichroic reflective film, and therefore does not affect the visible light characteristic change layer.

At this time, the control unit emits the second laser beam from the optical pickup based on the image data of the visible image to be formed, and the emitted second laser beam is collected on the label layer of the optical disc by the optical pickup. To be lighted. As a result, an image is formed on the label layer of the optical disc. At this time, the irradiated second laser beam passes through the dichroic reflection film and reaches the label layer.

At this time, the optical pickup is operated by the servo circuit based on the position information of the groove of the optical disk included in the light reception signal based on the reflected light from the dichroic reflection film of the irradiated first laser beam. Tracking control of the irradiated laser beam is performed. At the same time, the servo circuit controls the focus of the laser beam irradiated to the optical disk by operating the optical pickup based on the focus information of the first laser beam in the information recording layer of the optical disk included in the received light signal. Thereby, since the first and second laser beams are condensed by the same optical pickup, both the first and second laser beams are subjected to tracking control and focus control.

Further, at this time, the diameter that becomes 1 / e ² of the center intensity at the spot of the second laser beam in the label layer is larger than a predetermined pitch of the grooves formed in the information recording layer of the optical disc by the optical pickup. growing. Since the second laser beam applied to the label layer is tracked based on the groove formed on the information recording layer of the optical disc by the servo circuit, the irradiation pitch of the second laser beam in the radial direction of the optical disc is The predetermined pitch of the groove is the lowest pitch. Accordingly, since the diameter that becomes 1 / e ² of the center intensity at the spot of the second laser beam is larger than the lowest pitch of the irradiation pitch in the radial direction of the optical disc, an image formed by the irradiation of the second laser beam can be obtained. It can be continued in the radial direction of the optical disk. As a result, the image does not become comb-like, and a clear image can be printed on the label. In addition, an image can be formed at high speed.

In the invention of claim 5, in the invention of claim 4, the optical pickup comprises: a first laser diode that emits a first laser beam; a first laser diode driver that drives the first laser diode; A second laser diode that emits a second laser beam; a second laser diode driver that drives the second laser diode; and a second laser diode that focuses the first laser beam on the information recording layer of the optical disc and a second laser diode. An objective lens for condensing the laser beam on the label layer of the optical disk, and a diameter that is 1 / e ² of the center intensity at the spot of the second laser beam in the label layer having wavelength selectivity. A color filter that changes the numerical aperture of the objective lens for the second laser beam so as to be larger than the predetermined pitch. A tracking actuator that drives the objective lens in the radial direction of the optical disc, a focus actuator that drives the objective lens in the optical axis direction, and reflection of the first laser beam from the dichroic reflective film of the optical disc. A light receiving element that receives light and outputs a light reception signal based on the received reflected light.

According to a sixth aspect of the invention, in the fifth aspect of the invention, the servo circuit drives the tracking actuator based on position information of the groove included in the light reception signal to track the laser beam irradiated on the optical disc. And controlling the focus of the laser beam applied to the optical disc by driving the focus actuator based on the focus information of the first laser beam applied to the optical disc included in the received light signal. ing.

According to a seventh aspect of the invention, in the fifth or sixth aspect of the invention, the control unit drives the first laser diode driver based on the information recording data, and the second based on the image data. The laser diode driver is driven.

As described above, according to the present invention, the light having the numerical aperture changing section that changes the numerical aperture of the objective lens for the second laser beam to a value lower than the numerical aperture of the objective lens for the first laser beam. Since the pickup is provided, the diameter that is 1 / e ² of the center intensity at the spot of the second laser beam focused on the optical disc is the center intensity at the spot of the first laser beam focused on the optical disc. It becomes larger than the diameter at 1 / e ² of, when performing formation of a visible image on the optical disk, it is possible to form an image at high speed.

Further, according to the present invention, information can be reproduced or recorded by irradiating the optical disc with the first laser beam from the optical pickup, and the optical disc can receive the second laser beam from the optical pickup. Can be realized from the surface on which the information on the optical disk is reproduced or recorded to form a visible image, that is, an optical disk apparatus capable of performing label printing. It is not necessary to perform complicated operations such as preparing a printer apparatus, attaching a separately printed label sheet to an optical disk on which information is recorded, or turning the optical disk over and mounting it again in the apparatus.

Further, when forming a visible image, that is, label printing, not only the second laser beam is irradiated based on the image data of the visible image to be formed, but also the first laser beam is irradiated, and the servo circuit The focus control and tracking control of the laser beam irradiated to the optical disc are performed by operating the optical pickup based on the light reception signal based on the reflected light from the optical disc of the first laser beam irradiated with. As a result, since the first and second laser beams are collected by the same optical pickup, both the first and second laser beams are subjected to tracking control and focus control. An optical disc device capable of efficiently and accurately forming a visible image on the surface can be realized.

Further, the diameter that is 1 / e ² of the center intensity at the spot of the second laser beam in the label layer has a wavelength selectivity and a color filter aperture that changes the numerical aperture of the objective lens for the second laser beam. Therefore, the second laser beam irradiated to the label layer becomes larger than the predetermined pitch of the groove formed on the information recording layer of the optical disc, and is formed on the information recording layer of the optical disc by the servo circuit as described above. Therefore, the irradiation pitch of the second laser beam in the radial direction of the optical disc is the minimum pitch of the predetermined pitch of the groove. Accordingly, since the diameter that becomes 1 / e ² of the center intensity at the spot of the second laser beam is larger than the lowest pitch of the irradiation pitch in the radial direction of the optical disc, an image formed by the irradiation of the second laser beam can be obtained. It can be continued in the radial direction of the optical disk. This makes it possible to form images that are continuous in the radial direction of the optical disk at high speed, thereby realizing an optical disk apparatus that can form a visible image clearly and at high speed on the label surface of the optical disk.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 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 of the optical disc device according to the present embodiment. The operation and the like 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 reproduction and / or recording of a DVD accompanied by a reproduction and / or recording function of a CD can be used to reproduce and / or record DVD information, and a laser for the CD. Assume a DVD that enables label printing by irradiating a beam.

The DVD 50 shown in FIG. 1 has a thickness T of 1.2 mm, and also has a substrate 51, a recording dye film 52 as an information recording layer, a color filter (dichroic reflective film) 53, and a visible light characteristic as a label layer. The change layer 55 and the substrate 54 are sequentially stacked. The color filter 53
And the visible light property changing layer 55 is a transparent intermediate layer 56 made of an adhesive or the like for bonding the color filter 53 and the visible light property changing layer 55 together. FIG. 1 shows a DVD 50.
These structures are schematically shown, and the shape, dimensional 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 information on the DVD 50, control is performed so that the laser beam is focused on the groove 52 a (focus control).
At the same time, 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, and the recorded information is reproduced.

  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 of the present embodiment, the visible light characteristic changing layer 55 serving as a label layer 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.

In addition, the visible light characteristic changing layer 55 of the DVD 50 of the present embodiment is made of a material having a characteristic that the absorbance is maximized at the wavelength of light in the predetermined band. Absorbs almost all light. That is, the irradiated light of the predetermined band is hardly reflected, and almost all the energy of the irradiated light of the predetermined band is used as energy for changing (or deforming) the irradiated part. As a result, label printing can be performed efficiently without wasting energy.

The visible light characteristic changing layer 55 is not formed with a groove for guiding a laser beam irradiated for image formation. 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, and the manufacturing cost of the DVD 50 is that the groove is formed in the visible light characteristic change layer. Will be reduced.

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 performing 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. The optical disk apparatus shown in FIG. 3 is an optical disk apparatus that performs reproduction and / or recording of a DVD with a CD reproduction and / or recording function.

As shown in FIG. 3, the optical disc apparatus 100 is connected to a personal computer (PC) 110 as a back end, and includes an optical pickup 10, a front end processor (FEP) 13, and laser power control (LPC) circuits 14a and 14b. A servo circuit 15, a motor drive circuit 16, a control unit 17, a stepping motor 18, a driver 19, a motor controller 20, and a spindle motor 21.

The spindle motor 21 is a motor for rotationally driving the DVD 50 that is a target for recording and reproducing data, and the number of rotations is controlled by the motor drive circuit 16. The motor drive circuit 16 is supplied with an instruction signal from the control unit 17 and a pulse signal having a frequency corresponding to the number of revolutions of the spindle motor 21 fed back from the spindle motor 21 or a sensor provided in the spindle motor 21. The motor drive circuit 16 controls the rotation of the spindle motor 21 based on these supplied signals. The spindle motor 21 is rotationally driven by a method in which the DVD 50 is rotationally driven at a constant angular velocity (CAV method: Constant A).
ngular velocity) or a method of rotating the DVD 50 to achieve a constant recording linear velocity (
CLV method: Constant Linear Velocity), any of which may be used.

The optical pickup 10 is a unit that irradiates the DVD 50 that is rotationally driven by the spindle motor 21 with a laser beam.

FIG. 4 shows the configuration of the optical pickup 10. As shown in FIG. 4, the optical pickup 10
Laser beam L1 which is red light having a wavelength of 660 nm used for DVD reproduction or recording
A laser diode 37a that emits a laser beam L2 that is infrared light having a wavelength of 780 nm and is used for CD reproduction or recording and label printing.
7b and a laser diode driver (LDD) 11a for driving the laser diode 37a
A laser diode driver (LDD) 11b for driving the laser diode 37b;
The optical system 40 for condensing the laser beams L1 and L2 onto the DVD 50 (the recording dye film 52 and the visible light characteristic changing layer 55), the light receiving element 36 that receives the reflected light, and the light reception signal from the light receiving element 36 is amplified. The head amplifier (HA) 12 is provided.

The LDD 11a drives the laser diode 37a according to the instruction signal from the control unit 17 and the control signal from the LPC circuit 14a shown in FIG. 3, and the LDD 11b has the instruction signal from the control unit 17 and the control signal from the LPC circuit 14b. Accordingly, the laser diode 37b is driven.

When a drive current is supplied from the LDD 11a, the laser diode 37a emits a laser beam L1 having an intensity corresponding to the drive current. The laser beam L1 emitted from the laser diode 53a is transmitted through the diffraction grating 38a to the main beam and two sub beams (preceding beam,
These three laser beams L1 are separated into polarization beam splitters 39a.
39b, the collimator lens 30, the quarter wavelength plate 31, the color filter aperture 41, and the objective lens 32, as shown in FIG. 5, the light is condensed on the recording dye film 52 which is the recording surface of the DVD 50.

Since the laser beam L1 is reflected by the color filter 53 of the DVD 50, the laser beam L1 irradiated for reproducing or recording information on the recording dye film 52 forms an image on the visible light characteristic changing layer 55. Adverse effects such as forming an unintended image can be avoided.

The three laser beams L1 reflected by the color filter 53 of the DVD 50 are again
Objective lens 32, color filter aperture 41, quarter wave plate 31, collimator lens 30
The light beam is transmitted through the polarization beam splitter 39b, reflected by the deflection beam splitter 39a, and incident on the light receiving element 36 through the cylindrical lens 33.

The light receiving element 56 outputs the received signal to the head amplifier 12, and the received light signal is amplified by the head amplifier 12 and supplied to the FEP 13 and the servo circuit 15 shown in FIG. The FEP 13 demodulates the received light signal that has been subjected to the predetermined modulation to control the control unit 1.
7 is supplied.

Further, the servo circuit 15 relates to the position information of the groove 52a used for tracking control and the focus of the laser beam L1 focused on the recording dye film 52 used for focus control, which are included in the received light signal. Information (focus information) will be 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 11b, the laser diode 37b emits a laser beam L2 having an intensity corresponding to the drive current. The laser beam L2 emitted from the laser diode 53b is separated into a main beam and two sub beams (preceding beam and succeeding beam) by the diffraction grating 38b. These three laser beams L2 are polarized beam splitter 39b, collimator lens. 30, through the quarter wave plate 31, the color filter aperture 41, and the objective lens 32, as shown in FIG.
5 is condensed.

Here, the color filter aperture 41 is a dichroic reflective film like the color filter 53 of the DVD 50. However, unlike the dichroic reflection characteristic of the color filter 53, the dichroic reflection characteristic of the color filter aperture 41 has a high reflectance in the vicinity of the wavelength of 780 nm, and has a wavelength of 650 n.
It has high permeability in the vicinity of m. Accordingly, almost all of the laser beam L1 (wavelength 650 nm) incident on the color filter aperture 41 is the color filter aperture 41.
The laser beam L2 (wavelength 780 nm) incident on the color filter aperture 41 is partially reflected by the color filter aperture 41 and the remaining part is incident on the objective lens 32. It will be.

In other words, the effective diameter of the objective lens 32 for the laser beam L2 is smaller than the effective diameter of the objective lens 32 for the laser beam L1, in other words, the NA (Numerical) of the objective lens 32 for the laser beam L2. Aperture (numerical aperture) is smaller than the NA of the objective lens 32 for the laser beam L1. As a result, the laser beam L 1 is focused on the recording dye film 52, and the laser beam L 2 is focused on the visible light characteristic changing layer 55 located behind the recording dye film 52.

The NA of the objective lens 32 for the laser beam L1 is set to about 0.65. This is 1 / e ² of the center intensity at the spot of the laser beam L1 focused on the recording dye film 52.
(Hereinafter, the diameter that is 1 / e ² of the center intensity at the spot of the laser beam is simply referred to as the spot diameter) so as to match the track pitch (about 0.74 μm) of the DVD. It is to do. The spot diameter of the focused laser beam is proportional to the wavelength and NA.
Inversely proportional to

On the other hand, the NA of the objective lens 32 for the laser beam L2 is the color filter aperture 4.
1 is set to about 0.1 by reducing the diameter through which the laser beam L2 passes through the objective lens 32, that is, the effective diameter of the objective lens 32. This is because the spot diameter of the laser beam L2 condensed on the visible light characteristic changing layer 55 is at least a track pitch of DVD (about 0.74 μm), that is, a pitch of grooves formed in the recording dye layer 52. This is to make it large, several μm. The reason for this will be described later.

The color filter aperture 41 is disabled when the optical disk device 100 is a CD whose optical disk is mounted and the CD is reproduced or recorded. Therefore, in this case, the NA of the objective lens 32 with respect to the laser beam L2 is larger than 0.1, and the spot diameter of the laser beam L2 focused on the CD recording surface is the CD track pitch ( The size is adjusted to about 1.6 μm).

Further, a liquid crystal filter may be used instead of the color filter aperture 41. Even in the case of the liquid crystal filter, the spot diameter of the laser beam L2 applied to the label layer can be increased by changing the NA of the objective lens 32 for the laser beam L2 in the same manner as the color filter aperture 41. However, since the liquid crystal filter has no wavelength selectivity like the color filter aperture 41, when the liquid crystal filter is enabled, not only the laser beam L2,
The NA of the objective lens 32 for the laser beam L1 is also changed. Therefore, the liquid crystal filter cannot be used when label printing is performed by simultaneously irradiating laser beams L1 and L2, as described later, and is limited to use when label printing is performed by irradiating only the laser beam L2. .

Further, as described above, since the visible light characteristic change layer 55 has a characteristic of absorbing almost all infrared light, the laser beam L2 applied to the visible light characteristic change layer 55 is hardly reflected. In addition, almost all of the energy of the laser beam L2 applied to the visible light characteristic changing layer 55 is used as energy for changing (or deforming) the irradiated part.

Further, the optical pickup 10 has two front monitor diodes (not shown), and when the laser diodes 37a and 37b emit laser beams, a current is supplied to each front monitor diode that has received the emitted light. Each current is generated as shown in FIG.
It is supplied to the PC circuits 14a and 14b. The LPC circuit 14a, 1
4D is an LDD 11a so that laser power of a value that matches the target value of the optimum laser power indicated by the control unit 17 is emitted from the laser diodes 37a and 37b.
, 11b. The laser power control by the LPC circuits 14a and 14b performed here uses a current value supplied from the front monitor diode, and feedback is performed so that a laser beam having a target intensity is emitted from the laser diodes 37a and 37b. Control.

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 moves the objective lens 32 in the optical axis direction and the radial direction in accordance with a focus error (FE) signal and a tracking error (TE) signal supplied from the servo circuit 15.

The servo circuit 15 performs F based on the amplified light reception signal supplied from the head amplifier 12.
The E signal and the TE signal are generated and given to the focus actuator 34 and the tracking actuator 35, thereby performing focus control and tracking control.

Here, the above-described three laser beams L1 emitted from the optical pickup 10 and irradiated on the DVD 50 have one of the main beam spot centers positioned at the center of one groove 52a (see FIG. 1) of the DVD 50. The sub-beam spot is in the positional relationship such that the spot on the groove 52a is on the inner surface and the other beam spot is on the outer surface of the groove 52a.

Therefore, the servo circuit 15 calculates the difference in the intensity of the reflected light of the two sub beams detected by the light receiving element 36 using the light receiving signal given from the head amplifier 12, so that the main beam becomes the target groove. It is possible to know how much the inner side / outside side is displaced from the center of 52a, that is, the amount of tracking error. The servo circuit 15
Generates a TE signal for reducing the tracking error amount to zero, and controls the tracking actuator 35 with the TE signal, so that even if the DVD 50 rotates eccentrically, the main beam is placed at the center of the target groove 52a. It can be traced accurately (tracking control). Note that this tracking control is not limited to the above-described three-beam method, but a phase difference method (1
The beam tracking method may be used.

Further, as shown in FIG. 6, the light receiving element 36 actually has four detection areas a and b.
, C and d, and the main beam of the laser beam L1 imaged on the light receiving element 36 is
The cylindrical lens 33 becomes a vertical ellipse A when the objective lens 32 is close to the DVD 50, becomes a horizontal ellipse B when it is far away, and becomes a circle C when it is in focus.

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. Then, the servo circuit 15 generates an FE signal for setting the focus error amount to a predetermined value, and controls the tracking actuator 35 with the FE signal. Focus on the beam DVD5
It can be accurately adjusted to 0 (focus control).

Returning to FIG. 3, the stepping motor 18 is a motor for moving the optical pickup 10 in the radial direction of the set DVD 50. The motor driver 19 rotationally drives the stepping motor 18 by an amount corresponding to the pulse signal supplied from the motor controller 20. The motor controller 20 generates a pulse signal corresponding to the movement amount and the movement direction according to the movement start instruction including the movement direction and movement amount in the radial direction of the optical pickup 10 instructed from the control unit 17, and the motor driver 19. Output to. That is, the stepping motor 18 moves the optical pickup 10 in the radial direction of the DVD 50, and the spindle motor 21.
Rotates the DVD 50 to change the laser beam irradiation position of the optical pickup 10 to D.
It can be moved to various positions on the VD 50.

The control unit 17 includes a central processing unit (CPU) and a read only memory (ROM).
y), a RAM (Random Access Memory), a buffer memory, etc. (all not shown), and the CPU controls each part of the optical disk device 100 according to firmware (program) stored in the ROM. Various processes for playback or recording, and various processes for label printing, and when a CD is loaded, the C
Various processes for reproduction or recording with respect to D are centrally controlled. The RAM is used as a work memory for various processes.

At the time of reproduction, the control unit 17 uses an LDD 11a and an LPC 14a (in the case where the mounted optical disk is a CD, an LDD 11a) in order to emit a reproduction level laser beam from the optical pickup 10.
An instruction signal is given to D11b and LPC 14b). The reproduction level is the servo circuit 1 described above.
5 refers to the level of irradiation power at which reflected light necessary for focus control and tracking control can be obtained, and information (pits) recorded on the recording dye film 52 of the DVD 50 is read with a laser beam of this reproduction level. However, information recording on the recording dye film 52 cannot be performed. Then, it is read from the recording dye film 52 of the DVD 50 and FEP 13
Various data such as music data demodulated in step 1 is transmitted to the PC 110 as the back end.
The data is reproduced by 100 various reproducing means.

On the other hand, at the time of recording, recording data to be recorded on the DVD 50 is transmitted from the PC 110 as the back end and stored in the buffer memory in the control unit 17. The recording data includes information recording data such as music data and video data recorded on the recording dye film 52 of the DVD 50, and image data for performing label printing. This image data is data for forming a visible image on the surface of a disk-shaped optical disc, and the bitmap data of the image to be input to the PC 110 or formed on the label surface of the optical disc generated by the PC 110 is in polar coordinate format. This is data in which information indicating the gradation (shading) of each of a plurality of coordinate points on a large number of concentric circles centered on the center point of the optical disk is described.

Based on the recording data stored in the buffer memory, the control unit 17 causes the LDD 11a, LPC to emit a recording level laser beam from the optical pickup 10.
14a and / or the LDD 11b and the LPC 14b are provided with an instruction signal, information is recorded on the recording dye film 52 of the DVD 50, and an image is formed on the visible light characteristic changing layer 55. The recording level refers to the level of irradiation power for writing information (pits) to the recording dye film 52 in the case of the laser beam L1, and in the case of the laser beam L2, the visible light characteristic changing layer 55 is discolored (or deformed) or the like. The level of irradiation power for forming an image.

Next, the label printing operation on the DVD 50 of the optical disc apparatus 100 having such a configuration is performed.
This will be described with reference to the flowchart shown in FIG.

First, the DVD 50 is set in the optical disc apparatus 100, and when the user operates the PC 110, an instruction to start label printing on the set DVD 50 is given from the PC 110 to the control unit 17 (step S1). At this time, the image data of the image to be printed is also P.
The control unit 17 supplies the received image data to the control unit 17.
Stored in the buffer memory.

Next, the control unit 17 controls the motor drive circuit 16 so that the spindle motor 21 performs D
The VD 50 is rotated at a predetermined speed (step S2).

Next, the control unit 17 gives an instruction signal to the LDD 11a and the LPC 14a, and irradiates the DVD 50 with the laser beam L1 at the reproduction level from the optical pickup 10 (step S3). Thereafter, when the laser beam L1 is irradiated, the irradiated laser beam L1 is irradiated.
Focus control and tracking control by the servo circuit 15 described above are performed based on a light reception signal from the head amplifier 12 which is a signal of reflected light from the color filter 53 of one DVD 50.

Next, the control unit 17 gives a movement start instruction to the motor controller 20 based on the image data stored in the buffer memory, and moves the optical pickup 10 to a position where laser irradiation for image formation is performed (step). S4).

When the optical pickup 10 reaches the laser irradiation position based on the image data stored in the buffer memory, the control unit 17 gives an instruction signal to the LDD 11b and the LPC 14b, and records from the optical pickup 10 according to the image data. The DVD 50 is irradiated with the level laser beam L2 in accordance with the image data (step S5). Note that the irradiation power of the laser beam L2 at this time is determined according to the degree of gradation (shading) included in the image data.
As a result, an image is formed on the visible light characteristic changing film 55.

At this time, the laser beam L2 irradiated on the visible light characteristic changing layer 55 of the DVD 50 is controlled by the objective lens 32 by the servo circuit 15 based on the reflected light of the irradiated laser beam L1 at the reproduction level. Therefore, the image data on the visible light characteristic changing layer 55 is accurately aligned and focused on the coordinate point where the image data 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 L irradiated for image formation is used.
2, the laser beam L <b> 2 is accurately applied to a desired position on the visible light characteristic change layer 55 without performing focus control and tracking control based on the reflected light. Thereby, a desired image can be accurately formed on the label surface of the DVD 50.

Further, at this time, the laser beam L irradiated onto the visible light characteristic changing layer 55 of the DVD 50.
No. 2 is used as energy for discoloring (or deforming) the irradiated portion, so that energy can be efficiently formed without wasting energy. This makes it possible to form an image at high speed. In other words, if the image formation time is the same, image formation with higher resolution can be performed. Further, since the laser beam L2 is not reflected by the visible light characteristic changing layer 55, the laser beam L2 does not become stray light for control based on the reflected light of the laser beam L1, and stable control can be performed. .

At this time, the spot diameter of the laser beam L2 irradiated onto the visible light characteristic changing layer 55 is such that the NA of the objective lens 32 for the laser beam L2 is about 0.1 by the color filter aperture 41 as described above. Therefore, the size is several μm.
As described above, the laser beam L2 is tracking-controlled based on the position information of the groove included in the reflected light of the laser beam L1 at the reproduction level being irradiated, so that the diameter of the DVD 50 irradiated with the laser beam L2 is controlled. With respect to the irradiation pitch in the direction, the pitch of the grooves (about 0.74 μm) formed in the recording dye layer 52 is the lowest pitch. Therefore, since the spot diameter of the laser beam L2 is larger than the minimum irradiation pitch in the radial direction of the DVD 50,
Images formed by irradiation with the laser beam L2 can be continued in the radial direction of the DVD 50. In other words, this eliminates a comb-like shape as in an image formed by laser beam irradiation of a conventional optical disc apparatus, and a clear image can be printed on a label.

Further, the large spot diameter of the laser beam L2 irradiated on the visible light characteristic changing layer 55 also means that the area of the image formed by one irradiation of the laser beam L2 is large, so that image formation is performed. It is possible to reduce the time required for That is, label printing can be performed at high speed. When high-speed label printing is performed, the movement of the irradiation position of the laser beam L2 in the radial direction of the DVD 50 is within the spot diameter of the laser beam L2 irradiated on the visible light characteristic change layer 55 and the recording dye film 52. It is preferable to carry out in units of several pitches of the grooves formed in the above.

Then, the control unit 17 determines whether or not the image formation processing by the irradiation of the laser beam L2 has been performed on all the image data stored in the buffer memory, that is, whether or not the formation of the image to be formed has been completed. (Step S6) When it is determined that the formation has not been completed yet, the process returns to Step S4 to continue image formation.

On the other hand, when it is determined that the formation has been completed (step S6), the LDD 11a, LPC
An instruction signal is given to 14a, and the irradiation of the laser beam L1 from the optical pickup 10 is stopped, and the motor drive circuit 16 is controlled to stop the rotation of the DVD 50 by the motor 21 (step S7). This completes the label printing operation.

As described above, according to the optical disc apparatus 100 shown in the present embodiment, not only the original information is reproduced or recorded on the DVD 50, but also the laser beam is irradiated to the label layer accurately. A clear visible image can be formed at high speed. Also,
Once the user sets the recording surface of the DVD 50 to the optical pickup device 100 so as to face the optical pickup 10, the user only records information on the recording dye film 52 which is the recording surface of the DVD 50 in the same manner as the conventional device. Instead, a visible image can be formed on the visible light characteristic changing layer 55 which is the label surface. For this reason, the user does not need to prepare a dedicated printer device, and attaches a separately printed label sheet to a DVD on which information is recorded, or
There is no need to perform complicated operations such as turning over the DVD 50 and setting it again for label printing.

Further, in the DVD 50 described in the present embodiment described above, the laser beam L1 is used to perform tracking control and focus control of the laser beam L2 when performing label printing.
However, the irradiation of the laser beam L1 is not only for tracking control and focus control, but also for reproducing information recorded on the recording dye layer 52 or recording dye layer 52. It may be performed for recording information. That is, it is possible to simultaneously perform label printing on the label layer and information reproduction or recording on the information recording layer.

Further, in the DVD 50 described in this embodiment described above, a light source for DVD (630 nm)
Information is reproduced or recorded with a light source of ˜690 nm band, and a light source for CD (770 nm to 800 nm)
Although an example in which label printing is performed with a light source in the nm band is shown, the present invention can be applied to other examples. Specifically, for example, information is reproduced or recorded on an optical disk using a laser light source of 405 nm band which is a light source of next-generation DVD, and label printing is performed with a light source for DVD. The present invention is applicable.

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 element shown in FIG. 4 is a flowchart for explaining a label printing operation of the optical disk apparatus shown in FIG. 3.

Explanation of symbols

10 Optical pickup 11a Laser diode driver (LDD, first laser diode driver)
11b Laser diode driver (LDD, second laser diode driver)
12 Head Amplifier (HA)
13 Front-end processor (FEP)
14a, 14b Laser power control circuit (LPC)
DESCRIPTION OF SYMBOLS 15 Servo circuit 16 Motor drive circuit 17 Control part 18 Stepping motor 19 Driver 20 Motor controller 21 Spindle motor 30 Collimator lens 31 1/4 wavelength plate 32 Objective lens 33 Cylindrical lens 34 Focus actuator 35 Tracking actuator 36 Light receiving element 37a Laser diode (1st 1 laser diode)
37b Laser diode (second laser diode)
38a, 38b Diffraction gratings 39a, 39b Polarizing beam splitter 40 Optical system 41 Color filter aperture (numerical aperture changing portion)
50 DVD (optical disc)
51, 54 Substrate 52 Dye recording film (information recording layer)
53 color filter (dichroic reflective film)
55 Visible light property changing layer (label layer)
56 Transparent intermediate layer 100 Optical disk device 110 Personal computer (PC, back end)
L1 laser beam (first laser beam)
L2 laser beam (second laser beam)

Claims (7)

An information recording layer on which information is recorded by forming grooves at a predetermined pitch and irradiating the first laser beam, and a second laser beam having a wavelength band different from that of the first laser beam are irradiated. And a dichroic layer provided between the information recording layer and the label layer and having a higher reflectivity for the first laser beam than the reflectivity for the second laser beam. An optical disc apparatus that records information and forms a visible image by irradiating an optical disc including a reflective film with first and second laser beams from the information recording layer side,
A first laser diode that emits a first laser beam, a first laser diode driver that drives the first laser diode, a second laser diode that emits a second laser beam, and a second laser A second laser diode driver for driving a 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; and wavelength selectivity. The numerical aperture of the objective lens for the second laser beam so that the diameter that becomes 1 / e ² of the center intensity at the spot of the second laser beam in the label layer is larger than the predetermined pitch of the groove. A color filter aperture that changes the tracking angle, a tracking actuator that drives the objective lens in the radial direction of the optical disc, and Light having a focus actuator that drives the objective lens in the optical axis direction, and a light receiving element that receives the reflected light from the dichroic reflective film of the first laser beam and outputs a received light signal based on the received reflected light With a pickup,
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. A servo circuit for controlling the focus of the laser beam applied to the optical disc by driving the focus actuator based on the focus information of the laser beam;
A controller that drives the first laser diode driver when forming a visible image on the optical disc, and that drives the second laser diode driver based on the image data of the visible image to be formed;
An optical disc apparatus comprising: Information is reproduced or recorded by irradiation with the first laser beam, and an optical disk on which a visible image is formed by irradiation with a second laser beam having a wavelength band different from that of the first laser beam. An optical disc apparatus that reproduces or records information and forms a visible image by irradiating the first and second laser beams from the side of the optical disc where information is reproduced or recorded,
A laser beam emitting section for emitting the first and second laser beams, an objective lens for condensing the emitted first and second laser beams on the optical disc, and the objective lens for the second laser beam. An optical disc apparatus comprising: an optical pickup having a numerical aperture changing unit that changes a numerical aperture to a value lower than the numerical aperture of the objective lens for the first laser beam. The optical disk apparatus according to claim 2, wherein the numerical aperture changing section is a liquid crystal filter or a color filter aperture having wavelength selectivity. An information recording layer on which information is recorded by forming grooves at a predetermined pitch and irradiating the first laser beam, and a second laser beam having a wavelength band different from that of the first laser beam are irradiated. And a dichroic layer provided between the information recording layer and the label layer and having a higher reflectivity for the first laser beam than the reflectivity for the second laser beam. An optical disc apparatus that records information and forms a visible image by irradiating an optical disc including a reflective film with first and second laser beams from the information recording layer side,
The first and second laser beams are emitted, the emitted first laser beam is condensed on the information recording layer, and the emitted second laser beam has a central intensity of 1 at a spot in the label layer. / E ² is condensed on the label layer so that the diameter becomes larger than the predetermined pitch of the groove, and the reflected light from the dichroic reflecting film of the first laser beam is received and received. An optical pickup that outputs a light reception signal based on light;
Based on the groove position information included in the light reception signal, the optical pickup is operated 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. A servo circuit that controls the focus of the laser beam irradiated on the optical disc by operating the optical pickup based on the focus information of the laser beam;
A control unit that controls to emit a first laser beam from the optical pickup and emit a second laser beam based on image data of the visible image to be formed when forming a visible image on the optical disc; ,
An optical disc apparatus comprising: The optical pickup is
A first laser diode emitting a first laser beam;
A first laser diode driver for driving the first laser diode;
A second laser diode emitting 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 of the optical disc and condensing the second laser beam on the label layer of the optical disc;
The wavelength of the second laser beam is such that the diameter is 1 / e ² of the center intensity at the spot of the second laser beam in the label layer and is larger than the predetermined pitch of the groove. A color filter aperture for changing the numerical aperture of the objective lens;
A tracking actuator for driving the objective lens in the radial direction of the optical disc;
A focus actuator for driving the objective lens in the optical axis direction;
A light receiving element that receives reflected light of the first laser beam from the dichroic reflecting film of the optical disc and outputs a light receiving signal based on the received reflected light;
The optical disc apparatus according to claim 4, further comprising: The servo circuit drives the tracking actuator based on position information of the groove included in the light reception signal to perform tracking control of a laser beam applied to the optical disc, and records the information included in the light reception signal. 6. The optical disc apparatus according to claim 5, wherein the focus actuator of the laser beam applied to the optical disc is controlled by driving the focus actuator based on focus information of the first laser beam in the layer. The control unit drives a first laser diode driver and drives a second laser diode driver based on image data of the visible image when forming a visible image on the optical disc. The optical disc device according to claim 5 or 6.

Images