JP2008217876A - Optical pickup device and information recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device and an information recording and reproducing device for recording and reproducing information at high speed. <P>SOLUTION: The optical pickup device is provided with: a first laser beam source 10 emitting a first laser beam; a second light incident terminal 1 emitting a second laser beam of two beams or more having wavelength different from the first laser beam; a condensing means condensing a plurality of laser beams having different wavelength of two kinds which are emitted from the first laser beam source 10 and the second light incident terminal 1 on an information recording plane of a recording medium formed with a plurality of tracks; a dividing means dividing a plurality of reflected laser beams reflected by the information recording plane of the recording medium; and a phtodetecting means receiving the plurality of reflected laser beams divided by the dividing means, wherein the second laser beam incident terminal 1 comprises a bundle in which core clad type single mode optical fibers of at least two or more in each of which a clad is provided at the outer periphery of the core are close to each other and arranged in parallel, in one side end plane of individual single mode optical fiber, a core side diameter is kept and only a clad outside diameter is reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical pickup apparatus that records and reproduces information at high speed, and an information recording and reproduction apparatus that uses the optical pickup apparatus.

  As a recording medium suitable for information recording, reproduction, and erasure (repeated recording), for example, an optical disk is widely used. On the other hand, there are various standards for optical discs. For example, when classified by recording capacity, they are classified into CD standards and DVD standards. Further, when classified according to use, for example, data recording format, information is already stored (so-called “ROM”) read-only type, information recording is possible only once (so-called “−R”) write-once type (additional writing) Type) or rewritable type (recording / reproducing type or rewritable type) that can be repeatedly recorded and erased (so-called “RAM” or “RW”).

  On the other hand, when recording / reproducing information on / from an optical disc, a single laser beam is conventionally used. For example, in order to record / reproduce an optical disc of different standards such as the CD standard and the DVD standard described above, even though two laser beams are used for one pickup, the recording of the disc or the One laser beam was used for reproduction. For tracking, there is a method in which the laser beam is divided into three parts, but still one laser beam is used for recording and reproducing information.

  Although a method of emitting laser light with an optical fiber is also employed, only one laser light is emitted from the optical fiber for recording and reproducing information.

  A plurality of techniques for accurately recording / reproducing information on optical discs having different standards such as the CD standard and the DVD standard described above have been proposed (see, for example, Patent Document 1 to Patent Document 3).

JP 2006-209924 A JP 2006-331475 A JP 2006-344333 A

  As a method for recording and reproducing information at high speed, a method of rotating an optical disk at high speed is generally used. The method of rotating the optical disc at high speed is effective for recording and reproducing information at high speed, but has a limit. If it rotates at a higher speed than a certain number of revolutions, vibration may occur and information recording / reproduction may become impossible.

  The present invention provides an optical pickup apparatus and an information recording / reproducing apparatus for recording / reproducing information at a high speed by another approach.

  The optical pickup device and information recording / reproducing device of the present invention have the following features.

  (1) First laser light emitting means for emitting first laser light, and second laser light emitting means for emitting two or more second laser lights having wavelengths different from those of the first laser light A plurality of laser beams having two different wavelengths emitted from the first laser beam emitting unit and the second laser beam emitting unit are condensed on an information recording surface of a recording medium on which a plurality of tracks are formed. A condensing unit; a dividing unit that divides a plurality of reflected laser beams reflected on the information recording surface of the recording medium; and a light detecting unit that receives the plurality of reflected laser beams divided by the dividing unit. The second laser beam emitting means is a bundle of at least two single-mode optical fibers of a core-clad single-mode optical fiber in which a cladding is provided on the outer periphery of the core, and each single beam One end face of the mode optical fiber is an end face proximity multi-core optical fiber in which the outer diameter of the clad is reduced while the core diameter remains unchanged, and the two or more single mode optical fibers are arranged close together and bundled in parallel. And the condensing means causes each of the second laser beams to be incident on different tracks, and transmits the first laser beam and one of the second laser beams to the recording medium. It is made to enter the same track or a track in the vicinity of the second laser beam incident track, and the light detecting means is a focus and tracking control signal or a focus and tracking control signal based on the reflected laser beam of the first laser beam. And a first light detecting means for detecting information from the optical disc, and information on the recording medium based on a plurality of reflected laser lights of the second laser light. An optical pickup device having a second light detecting means for detecting information from the recording or the recording medium.

  (2) In the optical pickup device described in (1) above, the condensing unit further transmits the first laser beam and one of the second laser beams to the same track of the recording medium. And one or more other laser beams of the second laser beam are incident on different tracks of adjacent tracks.

  (3) First laser light emitting means for emitting the first laser light, and second laser light emitting means for emitting two or more second laser lights having different wavelengths from the first laser light. A plurality of laser beams having two or more different wavelengths emitted from the first laser beam emitting unit and the second laser beam emitting unit are condensed on an information recording surface of a recording medium on which a plurality of tracks are formed. A condensing unit; a dividing unit that divides a plurality of reflected laser beams reflected on the information recording surface of the recording medium; and a light detecting unit that receives the plurality of reflected laser beams divided by the dividing unit. The second laser beam emitting means is a bundle of at least two single-mode optical fibers of a core-clad type single-mode optical fiber in which a cladding is provided on the outer periphery of the core, and each thin One end face of a single-mode optical fiber is an end-face proximity multicore optical fiber in which the outer diameter of the clad is reduced while the core diameter remains unchanged, and the two or more single-mode optical fibers are arranged close together and bundled in parallel And the condensing means causes each of the second laser beams to be incident on different tracks, and transmits the first laser beam and one of the second laser beams to the recording medium. It is made to enter the same track or a track in the vicinity of the second laser beam incident track, and the light detecting means is a focus and tracking control signal or a focus and tracking control signal based on the reflected laser beam of the first laser beam. And a first light detecting means for detecting information from the optical disk, and information on the recording medium based on a plurality of reflected laser lights of the second laser light. Recording from a reflected laser beam from the recording medium detected by the optical pickup device having the second optical detection means for detecting information from the recording or the recording medium, and the first optical detection means and the second optical detection means An information recording / reproducing apparatus comprising: a signal processing circuit that extracts information recorded on a medium and sends information recorded on the recording medium; and a control device that controls the operation of the optical pickup device and the signal processing circuit. .

  (4) In the information recording / reproducing apparatus described in (3) above, the light condensing means of the optical pickup device further includes a first laser beam and one of the second laser beams. In the information recording / reproducing apparatus, the laser beam is incident on the same track of the recording medium, and the other one or more of the second laser beams are incident on different tracks of adjacent tracks.

  According to the present invention, with the above-described configuration, it is possible to record and reproduce information at a high speed without rotating the optical disk at a high speed to vibrate.

[Optical pickup device]
(First embodiment)
FIG. 1 is a schematic configuration example according to the first embodiment of the present invention. The optical pickup device according to the present embodiment includes a first laser light source 10 that is a first laser light emitting unit that emits a first laser light, and two or more second laser beams having wavelengths different from those of the first laser light. Of two different wavelengths emitted from the second light incident terminal 1, which is a second laser light emitting means for emitting two laser lights, and from the first laser light source 10 and the second light incident terminal 1. A condensing unit that condenses a plurality of laser beams on an information recording surface of a recording medium on which a plurality of tracks are formed; a dividing unit that divides a plurality of reflected laser beams reflected on the information recording surface of the recording medium; And a light detecting means for receiving the plurality of reflected laser beams divided by the dividing means.

  As shown in FIG. 1, the condensing means of the present embodiment is a first collimating lens that collimates (collimates) after the laser light from the first laser light source 10 passes through the first diffraction grating 9. 8, a second collimating lens for collimating two or more laser beams from the second light incident terminal 1, and two or more second laser beams having a wavelength different from that of the first laser beam; And an objective lens 12 that is focused on the recording surface of the optical disc 13 as a recording medium, and the first laser beam and one of the second laser beams are transmitted in the same manner as the optical disc 13. The light is incident on the track, and the other one or more of the second laser beams are incident on different tracks. Although the first laser beam may be incident on a track near the second laser beam incident track, the optical system is easier to adjust if it is incident on the same track.

  In addition, as shown in FIG. 1, the splitting unit of the present embodiment reflects the first laser light after the laser light reflected from the optical disk is captured by the objective lens 12 and has a substantially parallel cross-sectional beam shape. The laser beam is rotated by 90 degrees and deflected, and the plurality of reflected lights of the second laser beam pass through the dichroic mirror 7 as it is, and the plurality of reflected lights of the second laser beam that has passed through the dichroic mirror 7. And a deflecting mirror 5 that deflects the lens by rotating it 90 degrees.

  Further, the light detection means of the present embodiment reflects the first laser light after being captured by the objective lens 12 and deflected by being rotated 90 degrees by the dichroic mirror 7 and then diffracted by the first diffraction grating 9. A laser beam is received, and a focus and tracking control signal or a focus and tracking control signal and information from the optical disk are detected, and the light is captured by the objective lens 12 and passes through the dichroic mirror 7 as it is. Next, a plurality of reflected lasers of the second laser light that passes through the quarter-wave plate 6 (deflection control element), is rotated by 90 degrees by the deflecting mirror 5, and then is condensed by the second condenser lens 4. It comprises a second photodetector 3 for receiving light and recording information on the optical disc 13 or detecting information from the optical disc 13. The first photodetector 11 and the second detector 3 output current or voltage corresponding to the light intensity. The optical pickup device of the present embodiment includes a focus control coil (not shown) that moves the first photodetector 11, the second photodetector 3, and the objective lens 12 in a direction perpendicular to the surface of the optical disc 13. A tracking control coil for moving the objective lens 12 in the radial direction of the optical disk 13 is incorporated.

  The second light incident terminal 1 which is the second laser beam emitting means of the present embodiment includes at least two single-mode optical fibers of a core-clad single-mode optical fiber in which a cladding is provided on the outer periphery of the core. One end face of each single-mode optical fiber is a bundle, and the outer diameter of the clad is reduced with the core diameter unchanged, and the two or more single-mode optical fibers are bundled in close proximity and bundled in parallel. This is an end face proximity multicore optical fiber arranged and arranged. Details will be described later.

  Further, the configuration of the optical pickup device in the present embodiment will be described in detail. The second light incident terminal 1 has an end face of an adjacent seven-core optical fiber in which seven single-mode optical fibers are arranged in a dense manner as shown in FIG. 3 with a core interval of 40 μm. FIG. 3 schematically shows an end face of a close 7-core optical fiber, and has a structure having a bundle of optical fiber ferrules 14 and seven single mode optical fibers 15. For example, in the present embodiment, the single-mode optical fiber 15 has a clat diameter of 40 μm and a core diameter of 4.5 μm at the end face of the adjacent seven-core optical fiber. Adjustment was made so that a laser beam of about 650 nm was emitted from the end face of the adjacent 7-core optical fiber, which was used for recording and reproducing information. Although it is not necessary to emit light from all seven optical fibers, all of them are emitted simultaneously when used in the present embodiment. Although not shown in FIG. 1, light from a semiconductor laser emitting about 650 nm light is incident on each of the seven single mode optical fibers 15 as shown in FIG.

  As the second collimator lens 2, for example, an aspherical lens having a focal length of 26.5 mm is used, and the laser beam having a wavelength of about 650 nm emitted from the end face of the adjacent 7-core optical fiber is made almost parallel light.

  The second photodetector 3 is a seven-segment photodiode having the shape shown in FIG. 5 and is used to detect information recorded on the optical disk 13.

  The second condenser lens 4 is used to condense the light reflected from the optical disk 13 onto the second photodetector 3, and an aspheric lens having the same focal length of 26.5 mm as that of the second collimator lens 2 is used. Using. The focal length of the second collimator lens 2 may be further increased according to the distance between the individual photodiodes of the second photodetector 3.

  The polarizing mirror 5 was installed such that a dielectric thin film was applied on a glass substrate, 650 nm light from the second light incident terminal 1 passed therethrough, and 650 nm light returned from the optical disk 13 was reflected. A polarizing prism may be used instead of the polarizing mirror 5. The orientation of the semiconductor laser shown in FIG. 4 was adjusted so that 650 nm light from the second light incident terminal 1 would pass through the polarizing mirror 5, and the length of the optical fiber 18 was shortened to several tens of mm. Further, a polarization plane preserving fiber may be used.

  FIG. 4 schematically shows the relationship between the second light incident terminal 1 and a semiconductor laser that emits light of 650 nm. In FIG. 4, each laser beam emitted from seven laser light sources 16 is coupled by seven coupling lenses 17 and enters each of seven single mode optical fibers 18. As described above, the optical fiber ferrule 14 is formed by bundling seven single mode optical fibers 18.

  In the optical fiber ferrule 14 described above, the clad of the single mode optical fiber 18 having a clad diameter of 125 μm is thinned to about 40 μm by etching, and seven are closely bundled. Further, the light emission end face is polished so as to be in the same plane. The laser light source 16 is a semiconductor laser that emits light of 650 nm and has an output of 200 mW. The coupling lens 17 was an aspheric lens, and was adjusted so that the light emitted from the semiconductor laser 16 was efficiently incident on the single mode optical fiber 18. The single-mode optical fiber 18 has an NA of about 0.1, a core diameter of about 4.5 μm, a cladding diameter of about 125 microns, and a length of several tens of millimeters. The single mode fiber 18 was used in the portion of the optical fiber ferrule 14 with the cladding diameter reduced to 40 μm by etching.

  The quarter-wave plate 6 was installed in order to turn the 650 nm light from the second light incident terminal 1 into circularly polarized light and to rotate the 650 nm light returned from the optical disk 13 by 90 degrees.

  The dichroic mirror 7 was installed to reflect 780 nm light from the first laser light source 10 through which 650 nm light passes.

  The first collimator lens 8 converts the 780 nm light from the first laser light source 10 into a substantially parallel light, and condenses the 780 nm light returned from the optical disk 13 on the first photodetector 11.

  The first diffraction grating 9 diffracts the 780 nm light returned from the optical disc 13 in the direction of the first photodetector 11. Of course, 780 nm light from the first laser light source 10 is also diffracted, but the 0th-order light diffracted light is made incident on the optical disk 13, and the 780 nm light returned from the optical disk 13 uses the first-order light diffracted light. The light was incident on the photodetector 11.

  The first laser light source 10 emits a wavelength of 780 nm, and was used to detect a focus and tracking control signal or a focus and tracking control signal and information from the optical disc.

  The first photodetector 11 is a well-known quadrant photodiode, and detects a focus and tracking control signal or a focus and tracking control signal and information from the optical disc by a well-known method.

  The objective lens 12 is a lens having a numerical aperture NA of about 0.6 and a focal length of about 1.5, and collects light from the second light incident terminal 1 and the first laser light source 10 on the optical disk 13. Light up.

  The used optical disk 13 is a DVD standard disk and a CD standard disk. A DVD standard disc was used for information recording / reproduction, and a DVD standard disc and a CD standard disc were used for reproduction only.

  In the case of reproduction of a CD disc, only light from the first laser light source is used, information from the optical disc 13 is detected by a first photodetector, and information necessary for an information processing device (not shown) is obtained. Used after processing.

  In the case of recording / reproducing of a DVD disc, the light spot from the first laser light source 10 and the light spot emitted from the middle of the end face of the adjacent 7-core optical fiber of the second light incident terminal 1 are the same on the optical disc 10. It was made to concentrate on. For focus and tracking control, light from the first laser light source 10 is used and detected and controlled by the first photodetector 11. For recording / reproducing information, the light from the second light incident terminal 1 was used and the information was detected by the second photodetector 3.

Further, 7 of the second light incident terminal 1 is set such that the relationship between the track of the DVD disk as the optical disk 13 and the seven light spots from the second light incident terminal 1 are as shown in FIG. The position of the single-mode optical fiber was adjusted. FIG. 6 shows the relationship between the track 20 of the optical disc and the light spot 21 of the light from the second light incident terminal 1. The line in FIG. 6a schematically shows the track 20 of the optical disc, which is a group, land, or pit row, and the track pitch is 0.74 μm except for the DVD-RAM disc. FIG. 6 b shows a spot 21 on the optical disk of light from the second light incident terminal 1, and the interval ω μm from the adjacent spot is the core distance of seven single mode optical fibers of the second light incident terminal 1. And the product of the reduction magnification 1 / m of the second collimator lens 2 and the objective lens 12, which is given as follows.
ω = 40 / m ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Formula 1
In order for the seven light spots to enter the adjacent seven tracks, as shown in FIG. 6c, a track of the optical disk 12 and a straight line connecting the three spots including the center spot of the seven light spots are formed. If the angle formed is θ, the following relationship must be established. Note that the track pitch is p.
ω * sin (θ) = p Equation 2
ω * sin (60 + θ) = 3 * p Equation 3
ω * sin (60−θ) = 2 * p (4)
From Equations 2 to 4, the following is obtained.
2 * ω * sin (60) cos (θ) = 5 * ω * sin (θ) Expression 5
From Equation 5
tan (θ) = 0.4 * sin (60)
∴ θ≈19.1 degrees from Equation 2
ω ≒ 3.06 * p ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 6
When the DVD track pitch p = 0.74 μm is inserted, the distance ω between adjacent spots is as follows.
ω ≒ 2.26μm
From Equation 1
In the case of the present embodiment, the focal length of the second collimator lens 2 is 26.5 mm, the focal length of the objective lens is 1.5 mm, and the single mode optical fiber 7 of the second light incident terminal 1 is m≈17.7 times. The core interval of 40 μm is set to 2.26 μm between adjacent spots, and the magnification m is satisfied.

(Second Embodiment)
FIG. 2 shows a schematic configuration example of the second embodiment of the present invention. In the second embodiment of the present invention, the same optical members as those in the first embodiment are given the same numbers.

  The difference from the first embodiment is that the second diffraction grating 40 separates the light from the second light incident terminal 1 and the light returned from the optical disk 13. The rest is the same.

  In FIG. 2, the diffraction grating 40 diffracts the 650 nm light returned from the optical disk 13 in the direction of the second photodetector 3, similarly to the first diffraction grating 9. Of course, the 650 nm light from the second light incident terminal 1 is also diffracted, but the 0th-order light diffracted light is incident on the optical disk 13, and the 650 nm light returned from the optical disk 13 is converted into the first light using the primary light diffracted light. 2 was incident on the photodetector 3.

  Also in the first embodiment and the second embodiment, the 7-core optical fiber is used as the end-surface proximity multicore optical fiber. However, the configuration is not limited to 7 cores, and may be 3 cores or others.

  Further, although the CD and DVD disk have been described as the disks to be used, it goes without saying that other disks may be used. For example, DVD and Blu-ray disc. In this case, a semiconductor laser of about 650 nm is used as the first laser light source 10, and about 405 nm is used as the light emitted from the second light incident terminal 1.

  According to the pickup device using the 7-core optical fiber of the first embodiment and the second embodiment, information can be recorded / reproduced at a speed seven times faster than the conventional recording / reproduction using a single laser beam. It can be carried out.

[Information recording / playback device]
(Third embodiment)
1 shows an example of the configuration of an information recording / reproducing apparatus (optical disc apparatus) to which an embodiment of the present invention can be applied.

  As shown in FIG. 7, the information recording / reproducing apparatus, that is, the optical disc apparatus 100 uses the laser beam emitted from the optical pickup device 50 in the first embodiment or the second embodiment as described above as a recording medium, that is, an optical disc. By focusing on the 13 information recording layers, information can be recorded on the optical disc 13 and information can be reproduced from the optical disc 13. Since the optical pickup device 50 has been described in detail in the upper stage, it is omitted here.

  The optical disk 13 is supported by a turntable (not shown) of a disk motor (not shown), and is rotated at a predetermined speed by rotating the disk motor at a predetermined rotation speed.

  The optical pickup device 50 is moved at a predetermined speed in the radial direction of the optical disc 13 in each of the operations of recording, reproducing or erasing information by a pickup feeding motor (not shown).

  Signals detected by the first photodetector 11 and the second photodetector 3 (FIGS. 1 and 2) in the optical pickup device 50 are recorded in a recording signal processing circuit 60 that is a signal processing unit provided in a subsequent stage. The data signal used for information reproduction is processed to be usable. Further, the outputs from the first photodetector 11 and the second photodetector 3 (both shown in FIG. 1) are such that the position of the objective lens 12 (FIGS. Control signal for positioning in a predetermined positional relationship, that is, a focus error signal used for supplying the focus control signal to the focus control coil and a track error used for supplying the tracking control signal to the tracking control coil The signal is processed to be usable.

  Since information recording / reproduction by the second laser beam is performed simultaneously on a plurality of (for example, seven) tracks, when the track is a concentric circle or one spiral, the track feed needs to be sent by jumping a plurality of tracks every rotation. There is. Therefore, in the signal processing, the rotation of the disk is the same CAV method from the inner periphery to the outer periphery or the MCAV method in which a plurality of zones having the same rotation and different rotations are provided in the zone having the disk diameter rotate from the inner periphery to the outer periphery This is easier than in the case of the CLV method in which the number is constant. Of course, even in the CLV system, when spiral tracks corresponding to the number of the second laser beams are provided, track feeding can be performed continuously.

  The laser light reflected from the optical disk 13 is detected as an electrical signal by the first photodetector 11 and the second photodetector 3 of the optical pickup device 50. Output signals of the first photodetector 11 and the second photodetector 3 are amplified by a preamplifier 52 and connected to a controller (lens position control amount setting device (main control device)) 70 in a servo circuit (lens position). Control device) 54, RF signal processing circuit (output signal processing circuit) 62, and address signal processing circuit 64.

  In the servo circuit 54, focus servo of the objective lens 12 (FIG. 1) supported in the optical pickup device 50 (control of the difference in distance between the recording layer of the optical disc D and the objective lens with respect to the focal position of the objective lens). A signal and a tracking servo (control of the position of the objective lens in the direction crossing the track of the optical disk D) are generated, and each signal is sent to a focus actuator and a tracking actuator (lens position control mechanism) (not shown) of the optical pickup device 50, respectively. Is output.

  In the RF signal processing circuit 62, user data and management information are extracted from the signals detected and reproduced by the first photodetector 11 and the second photodetector 3, and in the address signal processing circuit 64, address information, That is, information indicating the track or sector of the optical disc 13 that the objective lens of the optical pickup device 50 is currently facing is extracted and output to the controller 70.

  In the controller 70, based on the address information, the position of the optical pickup device 50 is controlled in order to read out data such as user data at a desired position or to record user data and management information at a desired position. The

  At the time of recording information on the optical disc, under the control of the controller 70, the recording signal processing circuit 60 supplies the recording data modulated into the recording waveform signal suitable for recording on the optical disc, that is, the recording signal, to the laser driving circuit 56. Information to be recorded corresponding to the laser drive signal supplied from the laser drive circuit 56 from the second-light incident terminal 3 (FIGS. 1 and 2) using the seven-core optical fiber of the optical pickup device 50. A laser beam whose intensity is changed in accordance with is output. As a result, information is recorded on the optical disc 13.

[Optical pickup device]
(Fourth embodiment)
FIG. 8 is a schematic configuration example according to the fourth embodiment of the present invention.
FIG. 8 shows a modification of the optical fiber ferrule 14 corresponding to FIG. 3 of the first embodiment. The optical fiber 18 arrayed in a horizontal row is arranged in a rectangular ferrule 42 in three rows. It can be seen that the seven optical fiber bundles in FIG. 3 are arranged horizontally as a unit. The imaging optical system, signal processing system, and the like are exactly the same as those in the first to fourth embodiments. As a result, the recording signal processing speed can be increased by (3n-1) times.

  The optical pickup device and information recording / reproducing apparatus of the present invention can be effectively used in the field of recording / reproducing information on a recording medium.

It is a schematic block diagram of the optical pick-up apparatus of the 1st Embodiment of this invention. It is a conceptual block diagram of the optical pick-up apparatus of the 2nd Embodiment of this invention. It is a schematic diagram which shows an example of the end surface of a 7-core optical fiber near an end surface. It is a schematic diagram explaining the connection structure of an end surface near 7-core optical fiber and a semiconductor laser. It is a figure explaining the structure of the 7 division | segmentation photodetector of an example in this Embodiment. It is a figure which shows the structure of an example of the track | truck of an optical disk. It is a figure which shows the structure of an example of a light spot. It is a figure explaining the relationship between the track | truck and optical spot of an optical disk. It is a schematic block diagram which shows the structure of an example of the information recording / reproducing apparatus of the 1st Embodiment of this invention. It is a schematic block diagram of the optical pick-up apparatus of the 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 2nd light-incidence terminal, 2nd collimating lens, 3rd 2nd photodetector, 4th 2nd condensing lens, 5 deflection | deviation mirror, 6 1/4 wavelength plate, 7 dichroic mirror, 8 1st Collimating lens, 9 first diffraction grating, 10 first laser light source, 11 first light detector, 12 objective lens, 13 optical disk, 14 optical fiber ferrule, 15 light emitting fiber, 16 laser light source, 17 coupling lens, 18 Optical fiber, 40 Second diffraction grating.

Claims (4)

First laser beam emitting means for emitting the first laser beam;
Second laser beam emitting means for emitting two or more second laser beams having different wavelengths from the first laser beam;
A light collecting unit for condensing a plurality of laser beams having two different wavelengths emitted from the first laser beam emitting unit and the second laser beam emitting unit on an information recording surface of a recording medium on which a plurality of tracks are formed. Light means;
A dividing unit for dividing a plurality of reflected laser beams reflected on the information recording surface of the recording medium;
A light detecting means for receiving the plurality of reflected laser beams divided by the dividing means,
The second laser beam emitting means is a bundle of at least two single-mode optical fibers of a core-clad type single-mode optical fiber in which a cladding is provided on the outer periphery of the core, and each single-mode optical fiber One end face is an end face proximity multi-core optical fiber in which the outer diameter of the clad is reduced while the core diameter remains unchanged, and the two or more single mode optical fibers are arranged in close proximity and bundled in parallel.
The condensing means causes each of the second laser beams to be incident on different tracks, and causes the first laser beam and one of the second laser beams to be the same on the recording medium. Incident on a track or a track in the vicinity of the second laser beam incident track,
The light detection means includes a first light detection means for detecting a focus and tracking control signal or a focus and tracking control signal and information from the optical disk based on the reflected laser light of the first laser light, and a second laser. An optical pickup device comprising: a second light detection unit that records information on a recording medium based on a plurality of reflected laser beams of light or detects information from the recording medium. The optical pickup device according to claim 1,
The condensing means further causes the first laser beam and one of the second laser beams to be incident on the same track of the recording medium, and includes the second laser beam The other one or more laser beams are incident on different tracks of adjacent tracks. A first laser beam emitting unit that emits a first laser beam; a second laser beam emitting unit that emits two or more second laser beams having different wavelengths from the first laser beam; Condensing means for condensing a plurality of laser beams of two or more different wavelengths emitted from one laser light emitting means and a second laser light emitting means on an information recording surface of a recording medium on which a plurality of tracks are formed And a dividing unit that divides a plurality of reflected laser beams reflected on the information recording surface of the recording medium, and a light detecting unit that receives the plurality of reflected laser beams divided by the dividing unit, The second laser beam emitting means is a bundle of at least two single-mode optical fibers of a core-clad type single-mode optical fiber in which a clad is provided on the outer periphery of the core, and each single-mode optical fiber. One end face of the optical fiber is an end face proximity multi-core optical fiber in which the outer diameter of the clad is reduced while the core diameter remains the same, and the two or more single mode optical fibers are arranged close together and bundled in parallel. And the condensing means causes each of the second laser beams to be incident on different tracks, and transmits the first laser beam and one of the second laser beams to the recording medium. It is made to enter the same track or a track in the vicinity of the second laser beam incident track, and the light detecting means is a focus and tracking control signal or a focus and tracking control signal based on the reflected laser beam of the first laser beam. And a first light detecting means for detecting information from the optical disk, and recording information on a recording medium based on a plurality of reflected laser beams of the second laser beam An optical pickup device having a second light detecting means for detecting information from the recording medium,
A signal processing circuit for extracting information recorded on the recording medium from reflected laser light from the recording medium detected by the first light detecting means and the second light detecting means, and sending information recorded on the recording medium; ,
An information recording / reproducing apparatus comprising: the optical pickup device; and a control device that controls the operation of the signal processing circuit. The information recording / reproducing apparatus according to claim 3,
The condensing means of the optical pickup device further causes the first laser beam and one laser beam of the second laser beam to enter the same track of the recording medium, and the second laser beam An information recording / reproducing apparatus, wherein one or more other laser beams among the laser beams are incident on different tracks of adjacent tracks.

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