JPH05128578A - Optical disk drive - Google Patents

Abstract

PURPOSE:To obtain an optical disk drive which can record data to a recording layer of an optical disk formed of organic pigments at higher speeds. CONSTITUTION:A nonlinear optical element 28 and a moving mechanism 29 of the nonlinear optical element are added to an optical pickup device. At the recording time, the nonlinear optical element 28 is inserted into the optical path of a radiation light L1 of a laser source 22. In consequence, a second higher harmonic of the radiated light L1 is generated from the nonlinear optical element 28. The wavelength of the radiated light L1 is converted to 1/2. This radiated light L1a which is converted to a shorter wavelength is converged onto an optical disk 1 by an objective lens 25, thereby heating and deforming a recording layer 13 to record data. When the radiated light L1a converted to a shorter wavelength is used, it becomes possible to heat and deform the recording layer 13 in a short time because of the nature of the layer. Accordingly, the data can be recorded at higher speeds.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc device for recording / reproducing information on / from an optical disc having a recording layer made of an organic dye.

[0002]

2. Description of the Related Art FIG. 4 is a schematic configuration diagram of a conventional optical disk device of this type.

As shown in the figure, this optical disk device comprises an optical disk 1 and an optical pickup device 2 which is arranged so as to face the recording surface 11 of the optical disk 1.

In the optical disc 1, a recording layer 13 made of an organic dye is formed on a reflective layer 12, and the recording layer 13 is further formed.
It is constructed by forming a transparent protective layer 14 on the recording surface 11 above the disk, and rotates in a predetermined direction by a rotating shaft 15.

On the other hand, the optical pickup device 2 includes a laser light source 22 having a high frequency superimposing circuit 21 for noise reduction,
It is configured by combining a collimator lens 23, a beam splitter 24, an objective lens 25, a condenser lens 26, and a photodetector 27, and moves in the radial direction of the optical disc 1 by a drive mechanism (not shown).

In this optical pickup device 2, the radiation light L1 from the laser light source 22 is collimated by a collimator lens 23.
After being made parallel light by, it passes through the beam splitter 24,
It is converged on the optical disc 1 by the objective lens 25 and becomes a light spot LS. The reflected light L2 of the converged emitted light L1 from the reflection layer 12 of the optical disc 1 is incident on the objective lens 25 again and travels backward in the optical path of the emitted light L1 and is deflected by the beam splitter 24 in the perpendicular direction. The light is condensed by the condenser lens 26 and enters the photodetector 27.

By rotating the optical disc 1 and moving the optical pickup device 2, the position of the optical spot LS with respect to the optical disc 1 is moved,
Recording and reproduction are performed as described later.

That is, when the intensity of the emitted light L1 from the laser light source 22 of the optical pickup device 2 is set to a certain level or higher, the recording layer 13 of the optical disc 1 emits the emitted light L1.
The light spot LS is heated and is deformed according to the intensity of the emitted light L1. Therefore, information can be recorded on the recording layer 13 of the optical disc 1 by changing the intensity of the emitted light L1 while maintaining it at a certain level or higher.

The intensity of the reflected light L2 from the optical disk 1 changes according to the shape of the recording layer 13 on which information is recorded. Therefore, the intensity of the emitted light L1 from the laser light source 22 is set to a level that does not deform the recording layer 13, and the change in the intensity of the reflected light L2 from the optical disc 1 is detected by the photodetector 27.
It is possible to reproduce the record information of the recording layer 13 by detecting with.

By the way, the recording layer 13 made of the organic dye of the optical disk 1 has a property that the shorter the wavelength of the light is, the higher the absorptance of the light is, and thus, the recording layer 13 is easily heated and easily deformed. Therefore, in the conventional optical disc device, the wavelength of the emitted light L1 of the laser light source 22 is set so as not to deform the recording layer 13 of the optical disc 1 during reproduction.
Moreover, since the reflected light L2 becomes strong and the output of the photodetector 27 becomes large, a wavelength that is difficult to be absorbed by the recording layer 13 is selected.

[0011]

As described above, in the conventional optical disk device, the wavelength of the radiated light L1 of the laser light source 22 for recording and reproducing on the recording layer 13 of the optical disk 1 is set to the recording layer of the optical disk 1. Since the wavelength must be hard to be absorbed by the recording layer 13, it takes time to heat the recording layer 13 during recording.

Therefore, the conventional optical disk device has a drawback that the recording operation cannot be speeded up.

The present invention has been made to solve this drawback, and an optical disk device capable of recording information at a higher speed can be obtained by using light having a shorter wavelength during recording than during reproduction. To aim.

[0014]

In order to achieve the above object, in the optical disc device according to the present invention, the laser of the optical pickup device is arranged so that the emitted light having a shorter wavelength than that at the time of reproduction is converged on the optical disc at the time of recording. A wavelength switching means for switching the wavelength of the emitted light of the light source is provided.

[0015]

According to the optical disk device having the above-described structure, the recording layer of the optical disk is heated and deformed in a shorter time due to its properties by converging the emitted light having a shorter wavelength during recording onto the optical disk than during reproduction. Is possible.
As a result, information can be recorded at higher speed.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings showing the embodiments, constituent elements that are not different from those of the conventional example shown in FIG.

FIG. 1 is a schematic configuration diagram showing a first embodiment of an optical disk device according to the present invention.

As shown in the figure, in the optical disk device according to the first embodiment, a nonlinear optical element 28 for generating a second harmonic of the emitted light L1 by making the emitted light L1 of the laser light source 22 incident thereon, and its nonlinearity. A non-linear optical element moving mechanism 29 that inserts the optical element 28 into the optical path of the radiated light L1 and retracts it outside the optical path is added to the optical pickup device 2. In the present embodiment, the non-linear optical element 28 is inserted between the collimator lens 23 that makes the emitted light L1 from the laser light source 22 parallel light and the beam splitter 24 that deflects the reflected light L2 from the optical disc 1. ..

In the case of this optical disk device, the laser light source 22 is the same as in the case of the conventional example, the optical disk 1
A material that emits light having a wavelength that is difficult to be absorbed by the recording layer 13 is used. That is, the optical system of the conventional optical disk device can be used as it is.

In the optical disk device having the above structure, the non-linear optical element 28 is moved to the non-linear optical element moving mechanism 29 during recording.
And move it into the optical path of the radiated light L1. Then, the radiation light L from the laser light source 22 is transmitted to the nonlinear optical element 28.
When 1 is incident, the second-order harmonic of the emitted light L1 is emitted from the nonlinear optical element 28. That is, the wavelength of the emitted light L1 from the laser light source 22 is converted into a half by the non-linear optical element 28. The radiated light L1a converted into the short wavelength is transmitted to the beam splitter 2
4 and is converged on the optical disc 1 by the objective lens 25 to form a light spot LS. Then, the recording layer 13 of the optical disc 1 is heated and deformed by the short wavelength radiation L1a to record information.

The radiated light L1a thus converted into the short wavelength
Since the absorption rate of light in the recording layer 13 made of an organic dye is increased by using, the recording layer 1 of the optical disc 1
3 can be heated and deformed in a shorter time than when the radiation light L1 of the laser light source 22 is used as it is.
As a result, information can be recorded at higher speed.

On the other hand, at the time of reproduction, the nonlinear optical element 28 is retracted by the nonlinear optical element moving mechanism 29 to the outside of the optical path of the emitted light L1, and the emitted light L1 having a wavelength that is difficult to be absorbed by the recording layer 13 as in the conventional example. The recording layer 13 of the optical disc 1
And the change in the intensity of the reflected light L2 from the optical disc 1 is detected by the photodetector 27. As a result, the reflected light L2 does not deform the recording layer 13 of the optical disc 1.
The recorded information can be reproduced by strengthening.

Next, a second embodiment will be described with reference to the schematic diagram of FIG.

As shown in the figure, in the optical disk device according to the second embodiment, the optical pickup device 2 is provided with a recording laser light source 22a and a reproducing laser light source 22b for emitting lights L1a and L1b having different wavelengths. Has been. That is, the reproduction laser light source 22b emits light L1b having a wavelength that is difficult to be absorbed by the recording layer 13 of the optical disc 1, and the recording laser light source 22a emits light L1a having a shorter wavelength than the reproduction laser light source 22b. It radiates.

In the case of this embodiment, the recording laser light source 22 is used.
a is arranged in the same manner as the laser light source 22 in the first embodiment, and a first collimating lens 23a is provided between the recording laser light source 22a and the objective lens 25.
And the first beam splitter 24a are arranged.
In addition, the first beam splitter 24a and the reflected light L
The second beam splitter 24b is arranged between the light beam and the condenser lens 26 for condensing 2 on the photodetector 27, and the reproduction laser light source 22b corresponds to the second beam splitter 24b. It is arranged side by side with the laser light source 22a. Further, a second collimator lens 23b is arranged between the reproduction laser light source 22b and the second beam splitter 24b in parallel with the first collimator lens 23a. That is, in this configuration, the objective lens 25
Are commonly provided for both the recording and reproducing laser light sources 22a and 22b.

In the above structure, the recording laser light source 22
The radiated light L1a from a is emitted from the first collimator lens 23.
After being collimated by a, the first beam splitter 24a
Through the objective lens 25 and converges on the optical disc 1 to form a light spot LSa. As a result, information is recorded on the recording layer 13 of the optical disc 1.

On the other hand, the radiated light L1b from the reproduction laser light source 22b is collimated by the second collimator lens 23b, and then is diverted by the second beam splitter 24b in the direction perpendicular to the first beam splitter 24a. It is deflected and further deflected at a right angle by the first beam splitter 24a and converged on the optical disc 1 by the objective lens 25 to become a light spot LSb. The position of the light spot LSb of the emitted light L1b from the reproduction laser light source 22b is the position of the light spot LS of the emitted light L1a from the recording laser light source 22a.
It is the same as the position of a. Then, the reflected light L2 of the emitted light L1b from the optical disc 1 travels backward to the second beam splitter 24b, and the second beam splitter 24
b is transmitted, is condensed by the condenser lens 26, and is detected by the photodetector 27.
Incident on. As a result, the change in the intensity of the reflected light L2 is detected by the photodetector 27, and the recorded information is reproduced.

In this optical disk device, the recording laser light source 22a and the reproducing laser light source 22b are selectively caused to emit light to switch the wavelength of the emitted light to be used, and at the time of recording, the emitted light L1a having a shorter wavelength than that at the time of reproducing is emitted. It is converged on the optical disc 1. As a result, information can be recorded at a higher speed, as in the first embodiment.

In the second embodiment, one optical pickup device 2 is provided with a recording laser light source 22a and a reproducing laser light source 22b for emitting lights L1a and L1b having different wavelengths. The optical system of the optical pickup device 2 is divided into a recording optical system and a reproducing optical system, and a recording-dedicated optical pickup device 2a including a recording laser light source 22a, The reproduction-only optical pickup device 2b including the reproduction laser light source 22b and the photodetector 27 may be separately configured and arranged.

That is, at the time of recording, the radiated light L1 from the recording laser light source 22a of the recording-only optical pickup device 2a.
a is converged on the optical disk 1, and at the time of reproduction, the reproduction laser light source 22b of the reproduction-only optical pickup device 2b.
The emitted light L1b from the laser beam is converged on the optical disk 1 and the reflected light L2 is detected by the photodetector 27.

With this configuration, the same effect as that of the optical disk device in the first and second embodiments can be obtained.

[0032]

As described above, according to the optical disk device of the present invention, the recording of information can be performed at a higher speed by using the light having the shorter wavelength than that at the time of the reproducing.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a conventional example.

[Explanation of symbols]

 1 Optical Disc 11 Recording Surface 13 Recording Layer 2, 2a, 2b Optical Pickup Device 22 Laser Light Source 22a Recording Laser Light Source 22b Reproducing Laser Light Source 27 Photodetector 28 Nonlinear Optical Element 29 Nonlinear Optical Element Moving Mechanism

Claims (3)

[Claims] 1. Radiation from a laser light source provided in the optical pickup device, which comprises an optical disc having a recording layer made of an organic dye and an optical pickup device arranged so as to face the recording surface of the optical disc. Information is recorded by converging light on the optical disc and heating the recording layer of the optical disc, and detecting reflected light of the converged radiated light from the optical disc provided in the optical pickup device. In an optical disc device for reproducing information recorded on the recording layer of the optical disc by detecting with a detector, a non-linear optical element for generating a second harmonic of the emitted light by entering the emitted light of the laser light source, and the non-linear optical element Having a non-linear optical element moving mechanism that inserts the radiated light of the optical element into the optical path and retracts it from the optical path. Optical disk apparatus according to symptoms. 2. Radiation from a laser light source provided in the optical pickup device, which comprises an optical disc having a recording layer made of an organic dye and an optical pickup device arranged so as to face the recording surface of the optical disc. Information is recorded by converging light on the optical disc and heating the recording layer of the optical disc, and detecting reflected light of the converged radiated light from the optical disc provided in the optical pickup device. In the optical disc device for reproducing the recorded information on the recording layer of the optical disc by detecting with a detector, the laser light source is composed of a plurality of laser light sources that emit radiation lights of different wavelengths, and the plurality of laser light sources are single. An optical disc device provided in the optical pickup of. 3. Radiation from a laser light source provided in the optical pickup device, which is composed of an optical disc having a recording layer made of an organic dye and an optical pickup device arranged so as to face the recording surface of the optical disc. Information is recorded by converging light on the optical disc and heating the recording layer of the optical disc, and detecting reflected light of the converged radiated light from the optical disc provided in the optical pickup device. An optical disc device for reproducing information recorded in a recording layer of the optical disc by detecting with a detector, the optical pickup device including two optical pickup devices, each emitting light having a different wavelength, and emitting a short wavelength emission light. Is used for recording, and an optical pickup device that emits radiation of long wavelength is used for reproduction. That the optical disk device.