WO2006112135A1 - Optical pickup and information recorder/reproducer - Google Patents

Optical pickup and information recorder/reproducer Download PDF

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Publication number
WO2006112135A1
WO2006112135A1 PCT/JP2006/303154 JP2006303154W WO2006112135A1 WO 2006112135 A1 WO2006112135 A1 WO 2006112135A1 JP 2006303154 W JP2006303154 W JP 2006303154W WO 2006112135 A1 WO2006112135 A1 WO 2006112135A1
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WO
WIPO (PCT)
Prior art keywords
light
optical
light beam
pickup device
path
Prior art date
Application number
PCT/JP2006/303154
Other languages
French (fr)
Japanese (ja)
Inventor
Ikuya Kikuchi
Masakazu Ogasawara
Makoto Sato
Hajime Koyanagi
Katsuhiro Koike
Original Assignee
Pioneer Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pioneer Corporation filed Critical Pioneer Corporation
Publication of WO2006112135A1 publication Critical patent/WO2006112135A1/en

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
    • G11B7/127—Lasers; Multiple laser arrays
    • G11B7/1275—Two or more lasers having different wavelengths
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1356—Double or multiple prisms, i.e. having two or more prisms in cooperation
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B2007/0003—Recording, reproducing or erasing systems characterised by the structure or type of the carrier
    • G11B2007/0006—Recording, reproducing or erasing systems characterised by the structure or type of the carrier adapted for scanning different types of carrier, e.g. CD & DVD

Definitions

  • the present invention relates to an optical pickup device and an information recording / reproducing apparatus used for recording and reproducing information on an optical recording medium such as an optical disk.
  • CD Compact Disc
  • DVD Digital Versatile Disc
  • Optical discs for recording and reproducing data for example, BD (Blu-ray Disc) and High Definition-DVD (hereinafter, “HD-DVD”)
  • BD Blu-ray Disc
  • HD-DVD High Definition-DVD
  • Patent Document 1 Japanese Unexamined Patent Application Publication No. 2004-281008
  • the optical pickup device described in Patent Document 1 has a configuration in which a detector for CD and DVD and a detector for high recording density optical disc are separately provided. For this reason, when actually manufacturing this optical pickup device, it is essential to provide two detector substrates in the optical pickup and to provide a wiring for outputting a light reception signal for each substrate. Therefore, it has been difficult to downsize the optical pickup device itself.
  • An object of the present invention is to provide an optical pickup device and an information recording / reproducing device that can be realized.
  • the optical pick-up device includes three light beams each having a different wavelength, and the first one having the shortest wavelength.
  • a first light source that outputs a light beam; a second light source that outputs a second light beam having a longer wavelength than the first light beam; and a third light beam that has a longer wavelength than the second light beam.
  • An optical pickup device for receiving reflected light from the optical recording medium, respectively, wherein the first light source and the third light source are arranged at different positions, and the second light source is the first light source.
  • the second light beam is configured as a single unit, and a forward path condensing means for condensing the optical recording medium through the optical path substantially the same as the light beams from the other light sources unitized.
  • Receiving means for receiving the reflected light corresponding to the first, second and third light beams And an optical element that transmits or reflects the light depending on the polarization state of the incident light, and the first return path for condensing the reflected light incident through the first optical path on the light receiving means. And an optical element that transmits or reflects the light at a certain rate without depending on the polarization state of the incident light, and the reflected light incident through the second optical path is the light receiving means. And second return path condensing means for condensing the light.
  • an information recording / reproducing device includes the optical pickup device according to any one of claims 1 to 4 and the optical pickup device.
  • Driving means for controlling the optical recording medium control means for controlling recording and reproduction of information on the optical recording medium by controlling the driving means, and a signal corresponding to a light reception result in the optical pickup device is output.
  • Output means
  • FIG. 1 is a block diagram showing a configuration of an information recording / reproducing apparatus RP in an embodiment.
  • FIG. 2 is a diagram showing the reflection characteristics of dichroic PSB211 which is useful for the embodiment.
  • FIG. 3 is a diagram showing the reflection characteristics of a dichroic PSB211 according to Modification 1.
  • FIG. 4 is a block diagram showing a configuration of an information recording / reproducing apparatus RP2 in Modification 2.
  • FIG. 5 is a block diagram showing a configuration of an information recording / reproducing apparatus RP3 in Modification 3. Explanation of symbols
  • the optical beam output from the light source Depending on the polarization state of the light without using an optical element having a large energy loss, such as a half mirror, as a separating element for the light guiding direction) and the return path (that is, the direction for guiding the reflected light from the optical disk to the detector). It is desirable to use an optical element (for example, PBS: polarization beam splitter) that can change the transmission Z reflection characteristics.
  • PBS polarization beam splitter
  • the thickness of the protective layer, such as CD, and the optical system for optical discs do not use an optical element having polarization dependency with respect to light transmission Z reflection characteristics. There is a need to use the Z-return separation element without a forward path.
  • the optical system for the optical disk for a protective layer such as a CD and the high recording density type light combined with BD and HD-DVD De
  • the optical system for the disk is designed with a separate optical path, and (a) the optical system for the optical disk with a thick protective layer is a non-polarized optical system (specifically, the polarization-dependent forward path Z recovery).
  • the information recording / reproducing apparatus RP according to the present embodiment includes the optical pickup apparatus PU of the present application as a compatible recorder that records and reproduces data with respect to an optical disc DK corresponding to each recording format of CD, DVD, and BD. It is applied.
  • the information recording / reproducing apparatus RP is roughly classified into a signal processing unit SP, a control unit C, a drive circuit D, an optical pickup device PU, and an actuator servo.
  • the circuit AS and the reproducing unit P are included.
  • the signal processing unit SP has an input terminal.
  • the signal processing unit SP performs signal processing on data input through the terminal and outputs the data to the control unit C.
  • Specific processing contents performed in the signal processing unit SP are arbitrary. For example, after the input data is compressed by a compression method such as MPEG (Moving Picture Experts Group), the data is processed by the control unit. You may make it output to.
  • MPEG Motion Picture Experts Group
  • the control unit C is mainly configured by a CPU (Central Processing Unit), and controls each unit of the information recording / reproducing apparatus RP. For example, when data is recorded on the optical disc DK, the control unit C uses a drive signal for recording corresponding to the data input from the signal processing unit SP. When the data recorded on the optical disc DK is to be reproduced, the reproduction drive signal is outputted to the drive circuit D.
  • a CPU Central Processing Unit
  • the drive circuit D is mainly composed of an amplifier circuit, amplifies the drive signal input by the control unit C force, and supplies the amplified drive signal to the optical pickup device PU.
  • the amplification factor in the drive circuit D is controlled by the control unit C.
  • the amplification factor is controlled so that a light beam is output with the optical pickup device PU force recording power.
  • the “Recording power” means the amount of energy that causes phase change or dye discoloration in a phase change type optical disc DK (eg, DVD-RW) and a dye color change type optical disc DK (eg, DVD-R). .
  • the optical beam is output with the optical pickup device PU power playback power (that is, the amount of energy that does not cause color change in the optical disc DK).
  • the amplification factor is controlled by this.
  • the optical pickup device PU irradiates the optical disc DK (that is, BD, DVD, CD) corresponding to a plurality of recording formats based on the control signal supplied to the drive circuit D force with an optical disc DK.
  • the optical pickup device PU used to record and read data from In order to realize a powerful function, the optical pickup device PU according to the present embodiment roughly includes a light source unit 1, an optical unit 2, and a light receiving unit 3.
  • the light source unit 1 is an element for outputting an optical beam based on a drive signal supplied with a drive circuit D force.
  • the light source unit 1 includes a first semiconductor laser 11, a second semiconductor laser 12, and a third semiconductor laser 13.
  • Each semiconductor laser includes a first semiconductor laser 11 for BD, a second semiconductor laser 11, and a second semiconductor laser 13.
  • the semiconductor laser 12 is an element for outputting a DVD and the third semiconductor laser 13 is an element for outputting a CD light beam.
  • the second semiconductor laser 12 and the third semiconductor laser 13 are housed in a single package of the light source unit 10 (so-called two lasers and one package).
  • the light beams output from the lasers 12 and 13 in the light source unit 10 are output via an optical path different from the light beam output from the first light source 11.
  • the light source for CD and the light source for DVD are made into one package, and the light source for BD is arranged at a position different from the light source for BD, Light beam and power for CD, DVD completely It is output via the separated optical path.
  • the optical unit 2 includes an outward Z return path separating unit 21, a first collimator lens 22, a second collimator lens 23, a ⁇ ⁇ 4 plate 24, a first objective lens 251 and a second objective lens. And an actuator unit 25 having 252 for focusing the light beam output from the light source unit 1 on the optical disc DK.
  • an actuator unit 25 having 252 for focusing the light beam output from the light source unit 1 on the optical disc DK.
  • (a) the optical system for BD and (b) the optical system for CD and DVD are separated from each other.
  • the objective lens 251 is guided and transmitted through the first objective lens 251 to be applied to the optical disc DK.
  • the light beam output from each of the semiconductor lasers 12 and 13 of the light source unit 10 is applied to the optical disc DK via the second objective lens 252.
  • the forward Z return path separation unit 21 includes a dichroic PBS 211 and a half mirror 212.
  • the light beam output from the first semiconductor laser 11 is transmitted to the first collimator lens 22 as a light source.
  • the light beam output from the unit 10 is guided to the second collimator lens 23, while
  • the optical path of the light emitted from each of the collimator lenses 22 and 23 that is, the reflected light from the optical disc DK is synthesized. Then, the light is guided to the light receiving unit 3.
  • the half mirror 212 that constitutes the forward path Z return path separation unit 21 is configured to separate the outward path Z return path of the optical system for CD and DVD provided on the optical path between the light source unit 10 and the second collimator lens 23. It is an element.
  • This half mirror 212 transmits the light beam output from the light source unit 12 with a transmittance of 50%, for example, regardless of the polarization state of the incident light, and the remaining 50% of the light beam in the figure. (Hereinafter referred to as “in the figure”) Reflected upward. Further, when reflected light is incident from the second collimator lens 23, the reflected light is reflected downward in the figure with a reflectance of about 50%.
  • a non-polarizing optical system is realized in the optical system for CD and DVD.
  • the dichroic PBS 211 is a forward Z return path separation element of the BD optical system provided on the optical path between the first semiconductor laser 11 and the first collimator lens 22, and is used as a light reflecting element. It has both polarization dependency and wavelength dependency with respect to the radiation characteristics.
  • the light beam reflection characteristics of the dichroic PBS 211 will be described with reference to FIG. The same In the figure, the reflection characteristic for the S-polarized light beam is indicated by a solid line, and the reflection characteristic for the P-polarized light beam is indicated by a dotted line.
  • this dichroic PBS211 uses a P-polarized light beam for all wavelengths. , And has a property of transmitting almost all.
  • an S-polarized light beam has a sharp transmission-reflection characteristic change point in a predetermined wavelength region, and reflects almost all of the S-polarized light beam at a wavelength of 405 ⁇ m.
  • it has a characteristic of transmitting almost all the S-polarized light beam.
  • this dichroic PBS 211 functions as a PBS with respect to a light beam with a wavelength of 405 nm, and a polarization optical system is realized in the optical system for BD, whereas wavelengths of 650 nm and 780 nm are realized. It does not function as a PBS with respect to the light beam it has, but only realizes the function of simply transmitting the reflected light reflected downward in the figure by the half mirror 212.
  • the polarization characteristics shown in FIG. 2 are merely examples of polarization characteristics other than the wavelength regions A, A ′, B, and C to be used, and the present invention is not limited to this.
  • the optical pickup apparatus PU With the function of the powerful dichroic PBS 211, the optical pickup apparatus PU according to the present embodiment combines the optical paths of the reflected light beams of the light beam irradiated to the optical disc DK through different optical paths. The light is emitted toward one light receiving unit 3.
  • the first collimator lens 22 is disposed on the optical path of the light beam emitted from the first semiconductor laser 11, and constitutes an optical system for BD, while the second collimator lens 23 is a light source unit. It is placed on the optical path of the light beam emitted from 10 and constitutes the optical system for CD and DVD.
  • the ⁇ ⁇ 4 plate 24 is provided on the optical path of the outgoing light from the first collimator lens 22 and the second collimator lens 23, and performs mutual conversion between linearly polarized light and circularly polarized light.
  • the actuator unit 25 includes a first objective lens 251, a second objective lens 252 configured as a compatible objective lens, an objective lens holder 253 to which both objective lenses 251 and 252 are fixed, and the objective lens A movable mechanism 254 that integrally moves the holder 253, and based on a correction signal supplied from the actuator servo circuit AS, the position of the objective lens is changed to perform tracking servo and focus servo. Realize.
  • the light receiving unit 3 includes an alignment grating 31, an error detection lens 32, and an OEIC 33.
  • the light receiving unit 3 receives reflected light from the optical disc DK, and receives a light reception signal corresponding to the light reception result. Output the number.
  • the alignment grating 31 is a grating arranged on the optical path of the reflected light emitted from the forward path Z return path separation unit 21, and is provided for adjusting the position of the focused spot on the OEIC 33. It has been made.
  • the specific grating configuration of the alignment grating 31 is arbitrary, and it is sufficient that only the light beam to be aligned can be diffracted and the position of the focused spot on the OEIC 33 can be adjusted. For example, when the optical pickup device PU was manufactured, the optical axis was adjusted for the first semiconductor laser 11 and the second semiconductor laser 12 (or the third semiconductor laser 13), and the focused spot position on the OE IC 33 was adjusted. Assume a case.
  • the alignment grating 31 only needs to have a characteristic of diffracting only a light beam of 780 nm (650 nm).
  • the error detection lens 32 condenses the reflected light emitted from the alignment grating 31 on the OE IC 33.
  • the OEIC 33 is composed of, for example, a photodiode, receives a light beam emitted from the error detection lens 32, and outputs a light reception signal to the control unit C, the reproduction unit P, and the actuator servo circuit AS.
  • the reproduction unit P includes, for example, an addition circuit and an amplification circuit, and generates a reproduction RF signal based on the light reception signal supplied from the OEIC 33. Then, the reproducing unit P performs predetermined signal processing on the reproduced RF signal and then outputs it to the output terminal OUT.
  • the actuator servo circuit AS is composed of an arithmetic circuit, and generates a correction signal (specifically, a tracking error signal and a focus error signal) based on a light reception signal supplied from the OEIC 33 of the optical pickup device PU. And output to the actuator unit 25. As a result, the actuator unit 25 changes the position of the objective lens holder 253 based on the correction signal and performs tracking servo and focus servo. Become.
  • the tracking servo system can be a DPP system (differential push-pull system), a heterodyne system, or a 3-beam system.
  • the OEIC33 is provided with a light receiving part for receiving the secondary beam ( ⁇ primary light) and between the first semiconductor laser 11 and the light source unit 10 and the optical part 2. It is only necessary to provide a grating with three light beams (0th order light and ⁇ 1st order light) that are also emitted from the light source power by this grating.
  • an astigmatism method or a spot size method can be employed.
  • a cylindrical lens is used as the detection lens 32
  • the spot size method where the light receiving part of the OEIC33 should be divided into four parts
  • a hologram lens is used for the detection lens 32.
  • the light receiving part of OEIC33 should be divided into two.
  • the operation of the information recording / reproducing apparatus RP is as follows. Therefore, in the following, description will be made separately for both patterns, because the operation contents are different between (2) when 0 and 0 ⁇ 0 are used as the optical disc 0K.
  • the disc discriminating circuit detects that the inserted optical disc is a BD.
  • the user performs an input operation for recording or reproducing information on the optical disc DK to an operation unit (not shown).
  • the control unit C starts supplying drive signals to the drive circuit D in accordance with the input operation.
  • the control unit C supplies a drive signal corresponding to the signal supplied from the signal processing unit SP to the drive circuit D and also in the drive circuit D. Set the gain to a value corresponding to the recording power.
  • the operation may instruct the reproduction of information.
  • the control unit C supplies the driving signal for reproduction to the driving circuit D and sets the amplification factor in the driving circuit D to a value corresponding to the reproducing power.
  • the drive circuit D When the control unit C force drive signal is supplied in this way, the drive circuit D outputs a predetermined drive signal to the first semiconductor laser 11. As a result, a light beam (for example, P-polarized light) having a wavelength of 405 nm is output from the first semiconductor laser 11, and the light beam is transmitted through the diced mouth PBS PBS 211 and converted into parallel light by the first collimator lens 22. After the conversion, the light enters the ⁇ ⁇ 4 plate 24. Next, this light beam passes through the ⁇ 4 plate 24 and shifts to a circularly polarized state, and is condensed on the recording surface of the optical disc DK by the first objective lens 251.
  • a light beam for example, P-polarized light
  • the light beam passes through the ⁇ 4 plate 24 and shifts to a circularly polarized state, and is condensed on the recording surface of the optical disc DK by the first objective lens 251.
  • the light beam condensed on the recording surface of the optical disc DK in this way is reflected on the recording surface, passes through the first objective lens 251 as reflected light, and then again becomes the ⁇ 4 plate
  • the direction of polarization changes by ⁇ ⁇ 2 in the forward path, for example, a light beam that has been polarized in the forward path becomes S-polarized in the return path.
  • the reflected light whose polarization direction has been changed after passing through the ⁇ 4 plate 24 is transmitted downward through the first collimator lens 22 and then reflected downward by the dichroic PBS 211, and passes through the alignment grating 31. Then, the light enters the error detection lens 32 and is condensed on the OEIC 33.
  • the OEIC 33 sends the received light signal corresponding to the reflected light to the reproduction unit ⁇ ⁇ , the control unit C, and further to the actuator servo circuit AS. Output.
  • a signal corresponding to the information recorded on the optical disc is output from the playback unit P during playback.
  • the control unit C controls the amplification factor of the drive circuit D to control the amount of light beam output from the first semiconductor laser 11, and the actuator servo circuit AS drives the actuator unit 25.
  • the drive circuit D uses the second semiconductor laser 12 or the third semiconductor laser of the light source unit 10 based on the drive signal to which the control unit C force is also supplied.
  • a predetermined drive signal is output to 13.
  • a light beam (for example, P-polarized light) having a wavelength of 650 nm or 780 nm is emitted from the light source unit 10, and the light beam passes through the half mirror 212, for example, about 50%. After being transmitted at the transmittance, the light enters the second collimator lens 23.
  • this light beam is converted into parallel light by the second collimator lens 23, then passes through the ⁇ ⁇ 4 plate 24 and shifts to a circularly polarized state, and is transferred onto the recording surface of the optical disc DK by the second objective lens 252. It is condensed.
  • the light beam irradiated on the recording surface of the optical disc DK is reflected on the recording surface, passes through the second objective lens 252 as reflected light, and then passes through the ⁇ 4 plate 24. To do.
  • the reflected light shifts to an elliptically polarized state according to the amount of birefringence of the optical disc DK, centering on the linearly polarized light whose polarization direction has changed by ⁇ 2 in the forward path (in the case of DVD, birefringence Is less affected).
  • the reflected light then passes through the second collimator lens 23, and has a reflectance of about 50% (that is, from the light source unit 10) regardless of the amount of birefringence of the optical disk DK in the half mirror 212. Is reflected downwards in the figure).
  • the reflected light passes through the dichroic PBS 211 and is incident on the alignment grating 31.
  • the alignment grating 31 diffracts the reflected light in accordance with the characteristics of the grating.
  • the light emitted from the alignment grating 31 is condensed on the OEIC 33 by the error detection lens 32.
  • the reflected light is received by the OEIC 33, and a tracking servo or the like is realized.
  • the light source unit 1 is provided with the first semiconductor laser 11 and the light source unit 10 having two lasers and one package, and (i ) An optical system for BD and (ii) an optical system for CD and DVD are provided separately, and further, (i) no polarization dependence, no, one mirror 212 and ( ii) A polarization-dependent and wavelength-dependent dichroic PBS 211 is provided to collect the reflected light on a single OEIC 33.
  • the reflected light of the light beams output from the first to third semiconductor lasers 11 to 13 are all focused on the OEIC 33, and information can be recorded on recording media corresponding to three different recording formats.
  • the optical system for BD is a polarization optical system
  • the optical system for CD and DVD is a non-polarization optical system. Therefore, it is possible to record and reproduce data on the optical disc DK under optimum conditions for each recording format.
  • the PBS 511 functions as a PBS with respect to a light beam with a wavelength of 405 nm, while the dichroic PBS 211 having simple transmission characteristics is used with respect to the light beams with a wavelength of 650 nm and 780 nm. Since the Z return path is separated, the outbound Z return path can be separated without providing a complicated configuration in the apparatus, and the apparatus can be downsized.
  • the power described in the case of realizing a BD, DVD, and CD compatible recorder is taken as an example.
  • An information recording / reproducing apparatus RP that records and reproduces information on various different optical discs DK can also be realized by the same configuration as that of the above embodiment.
  • the alignment grating 31 is not necessarily required.
  • a similar light receiving mode can be realized by devising the divided shape of the light receiving portion of the OEIC 33. In this case, the position of the focused spot on the OEIC 33 after the alignment of the optical axis is experimentally obtained in advance, and a light receiving portion is provided at that position.
  • a device eg, CPU
  • the configuration example in which the second semiconductor laser 12 and the third semiconductor laser 13 are packaged in the light source unit 10 and the DVD optical system is designed as a non-polarizing optical system has been described.
  • a polarizing optical system can be adopted for the DVD optical system.
  • the first semiconductor laser 11 and the second semiconductor laser 11 The light source unit may be configured with the conductor laser 12 as one package.
  • Figure 3 shows the reflection characteristics of the Dyke mouth PBS211 when this configuration is adopted.
  • the reflection characteristic for the S-polarized light beam is indicated by a solid line
  • the reflection characteristic for the P-polarized light beam is indicated by a dotted line.
  • the dichroic PBS 211 it is necessary for the dichroic PBS 211 to reflect almost all of the P-polarized light beam over the entire wavelength region.
  • an S-polarized light beam for example, a sharp transmission-reflection characteristic change point is provided in the vicinity of 700 nm, and almost all of the S-polarized light beam is reflected at wavelengths of 405 nm and 650 nm.
  • the wavelength of 780 nm it is necessary to have a characteristic of transmitting almost all the S-polarized light beam.
  • dichroic PBS211 can function as a PBS for light beams with wavelengths of 405 nm and 650 nm, and a simple transmission characteristic can be given for light beams with a wavelength of 780 nm. It becomes possible.
  • the optical pickup device PU that is effective in this modification, ( a ) the light beam output from the light source unit in which the first semiconductor laser 11 and the second semiconductor laser 12 are knocked is the first.
  • the collimator lens 22 is irradiated with the light beam output from the third semiconductor laser 13 to the second collimator lens 23, respectively, while (b) the light emitted from the collimator lenses 22 and 23 (that is, the optical disk). All the light reflected from the DK is guided to the light receiver 3.
  • the optical pickup device PU that is effective in the present modification, the first semiconductor laser 11 for BD and the second semiconductor laser 12 for DVD are combined into one package.
  • the reflected light can be collected on a single OEIC 33.
  • information can be recorded on and reproduced from recording media that support three different recording formats, while miniaturization of the optical pickup device can be realized, and the optical system for BD and DVD can be realized.
  • Non-polarization optics and CD optics With a polarization optical system, data can be recorded on and reproduced from the optical disc DK under optimum conditions for each recording format.
  • the first collimator lens 22 is simply provided for the BD optical system.
  • the optical disc DK that achieves a high recording density such as the BD format, it is highly necessary to increase the numerical aperture of the objective lens and narrow down the focused spot. Therefore, it is necessary to appropriately correct the spherical aberration that occurs and the coma caused by the tilt of the optical disc DK.
  • the information recording / reproducing apparatus RP2 that is effective in the present modification has a configuration in which an aberration correction mechanism 220 for correcting spherical aberration is provided for the BD optical system of the optical pickup apparatus PU2. I decided to adopt it.
  • a block diagram showing the configuration of the information recording / reproducing apparatus RP2 according to this modification is shown in FIG. In the figure, elements similar to those in FIG. 1 are given the same reference numerals.
  • the optical pickup device PU 2 that works well with this modification has an aberration correction mechanism 220 including a first collimator lens 22.
  • the aberration correction mechanism 220 is an element provided for correcting aberrations with respect to the light beam incident from the light source side and the reflected light from the optical disc DK, and includes the first collimator lens 22 and the collimator lens 22.
  • a lens holder 222 for fixing and a step motor 223 are provided.
  • the lens holder 222 constituting the aberration correction mechanism 220 is supported by the main shaft 224 and the sub shaft 225 so as to be movable in parallel with respect to the optical axis direction, and is used as a drive signal supplied from the step motor servo circuit SS.
  • the lens holder 222 is configured to translate in the optical axis direction as the step motor 223 is rotationally driven.
  • the collimator lens 22 moves based on the force applied, and the aberration correction function is realized by the diffusion and convergence of the light emitted from the collimator lens 22, that is, the incident light from the first objective lens 181 and the second objective lens 182. Is done.
  • the step motor servo circuit SS is composed of an arithmetic circuit and a recording memory (not shown).
  • Various sensors for example, a position sensor for detecting the position information and initial position of the collimator 151 provided in the sensor SE, OEIC33, Spherical aberration correction supplied from the signal processor SP
  • the step motor 223 is driven on the basis of a signal necessary for performing (for example, an envelope signal, a spherical aberration error signal, jitter, etc.).
  • the information recording / reproducing apparatus RP2 that is effective in the present embodiment can correct aberrations that occur on the optical path of the optical pick-up apparatus PU2.
  • step motor servo circuit SS actually drives the step motor 223 is arbitrary.
  • the detection signal value from the sensor SE and the signal value of the envelope signal are used.
  • the corresponding correction amount may be stored in a table on a memory (not shown) and the step motor 223 may be driven based on this table!
  • the information recording / reproducing apparatus RP2 that is effective in the present modification employs a configuration in which the aberration correction mechanism 220 is provided and this aberration correction mechanism 220 is driven by the step motor servo circuit SS. Even when it is necessary to narrow down the condensing spot using a lens with a large numerical aperture as in the BD format, it becomes possible to correct aberrations due to spherical aberration or chromatic aberration. Therefore, it is possible to effectively reduce the error appearance probability at the time of recording / reproducing information with respect to the optical disc DK.
  • a configuration in which aberration correction is realized by moving the collimator lens is employed.
  • aberration correction using a beam expander or a liquid crystal panel is used.
  • a similar function can be realized using an element.
  • the configuration example of the aberration correction mechanism using the beam expander is similar to the configuration described in, for example, Japanese Patent Application Laid-Open No. 2002-170274, and a specific method for correcting aberration when a liquid crystal element is used. Since the configuration is the same as that described in Japanese Patent Laid-Open No. 2002-358690, the details are omitted.
  • the first collimator lens 22 and the first objective lens 251 are provided in the optical system for BD, and the second collimator lens 23 and the second objective lens 252 are provided in the optical system for CD and DVD.
  • the same function as that of the above-described embodiment can be realized by a configuration using a single collimator lens and a single objective lens.
  • Figure 5 shows the configuration of the information recording / reproducing device RP3 that employs this powerful configuration. In the figure, the same elements as in FIGS. 1 and 4 are the same. Like symbols are attached.
  • the actuator unit 250 which is effective in this modification, is provided with a compatible objective lens 2501 having a numerical aperture corresponding to three recording formats of BD, DVD and CD.
  • This compatible objective lens 2501 is fixed to the objective lens holder 2502 and can be moved by the movable mechanism 2503.
  • the single collimator lens 221 is fixed to the lens holder 222, and this lens holder 222 is moved in parallel to the optical axis direction by the step motor 223 as in the second modification. It has been.
  • the optical path combining unit 210 is provided.
  • This optical path combining unit 210 is provided on the optical path of the light beam emitted from the light source unit 10 and the mirror 2101 provided on the optical path of the light beam emitted from the first semiconductor laser 11, and has a wavelength of 405 nm. It has a dichroic mirror 2102 that reflects a light beam while transmitting a light beam having a wavelength of 650 nm and 780 nm.
  • the optical beam output from the first semiconductor laser 11 is transmitted through the dichroic PBS 211 by the function of the optical path synthesizing unit 210, and is reflected upward by the mirror 2101 in the figure, so that the dichroic mirror 2102 As a result, the light is reflected to the right in the figure and is incident on the collimator lens 221.
  • the reflected light of the light beam on the optical disk DK is reflected downward by the dichroic mirror 2102 through the collimator lens 221, then reflected leftward by the mirror 2101, and further dichroic. It is reflected downward in the figure by the PBS PBS 211 and guided to the light receiving unit 3.
  • the light beam output from the light source unit 10 passes through the half mirror 212 and the dichroic mirror 2102 and enters the collimator lens 221. Then, the reflected light of the optical beam on the optical disk DK is transmitted through the dichroic mirror 2102, reflected downward in the drawing by the half mirror 212, and transmitted through the dichroic PBS 211 to be guided to the light receiving unit 3. It becomes.
  • the information recording / reproducing apparatus RP3 which is effective in this modification, information is recorded / reproduced with respect to the optical disc DK corresponding to the three recording formats while using the single collimator lens 221 and the compatible objective lens 2501. This makes it possible to further reduce the size of the optical pick-up device PU3.

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Abstract

An optical pickup which records/reproduces information in/from a recording medium corresponding to three different recording formats while realizing reduction in size. An optical system for CD and DVD and an optical system for BD (Blu-ray Disc) are provided independently and each optical system is provided with a light source unit (10) packaging a second semiconductor laser (12) for DVD and a third semiconductor laser (13) for CD, and a first semiconductor laser (11) for BD. A dichroic PBS (211) and a half mirror (212) are provided at a separating section (21) of going path/return path wherein (a) a light beam outputted from the first semiconductor laser (11) is led to a first collimator lens (22) and a light beam outputted from the light source unit (10) is led to a second collimator lens (23), and (b) light is led to a light receiving section (3) by combining the optical paths of reflected light from an optical disc (DK). Consequently, single detector optical pickup (PU) is realized and the size is reduced.

Description

光ピックアップ装置及び情報記録再生装置  Optical pickup device and information recording / reproducing device
技術分野  Technical field
[0001] 本発明は、光ディスク等の光学式記録媒体に対する情報の記録及び再生に用いる 光ピックアップ装置及び情報記録再生装置に関する。  The present invention relates to an optical pickup device and an information recording / reproducing apparatus used for recording and reproducing information on an optical recording medium such as an optical disk.
背景技術  Background art
[0002] 近年、 CD (Compact Disc)や DVD (Digital Versatile Disc)と 、つた光ディスクの分 野においては急速な記録密度の向上が図られ、最近では青色のレーザ光 (波長 40 5nm)を用いてデータの記録及び再生を行う光ディスク（例えば、 BD (Blu-ray Disc) 及び High Definition-DVD (以下、「HD— DVD」））が規格化されるに至っている。そ の一方において、新たな記録フォーマットを有する光ディスクが出現したとしても光デ イスクの完全なる切換には、未だ想到の時間を要することが想定され、今後も CDや D VDは広く流通することが予想される。力かる現状に鑑みた場合、これら複数の記録 フォーマットに対応した光ディスク（例えば CDと DVD及び BD)に対して如何にして 1 台の装置にて情報の記録再生を行うか、すなわち、如何にしてコンパチビリティ (互 換性)を実現するかが大きな課題となる。  [0002] In recent years, the recording density of CD (Compact Disc) and DVD (Digital Versatile Disc) and other optical discs has been rapidly improved, and recently, blue laser light (wavelength 405 nm) has been used. Optical discs for recording and reproducing data (for example, BD (Blu-ray Disc) and High Definition-DVD (hereinafter, “HD-DVD”)) have been standardized. On the other hand, even if an optical disc with a new recording format appears, it is expected that it will still take a long time to completely switch the optical disc, and CDs and DVDs will continue to be widely distributed in the future. is expected. In view of the current situation, how to record / reproduce information with one device for optical discs (eg CD, DVD and BD) that support these multiple recording formats, that is, how A major issue is whether to achieve compatibility.
[0003] ここで、力かるコンパチビリティを備えた情報記録再生装置 (所謂、コンパチブルレ コーダ）の実現方法としては、例えば、各記録フォーマット毎に別個独立した光ピック アップ装置を設け、情報の記録再生対象となる光ディスクの種別に応じて利用する光 ピックアップ装置を切り換えるという手法も考えられる。しかし、かかる方法は、情報記 録再生装置の製造コストの上昇と装置の大型化と!、う弊害を招来しかねず、現実的 な選択肢ということができない。かかる観点から、従来、一つのパッケージ内に、 CD 用の半導体レーザと DVD用の半導体レーザをパッケージングした光源ユニットと、高 記録密度型の光ディスク（具体的には、 BD等)用の半導体レーザとを配置し、所謂、 互換対物レンズ (すなわち、内周側と外周側でレンズの開口数を異ならせた対物レン ズ)を用いて、各光源から出力された光ビームを各記録フォーマットに対応した光ディ スク上に集光させる方法が提案されて ヽる (特許文献 1参照)。 特許文献 1：特開 2004— 281008号公報 [0003] Here, as a method for realizing an information recording / reproducing apparatus (so-called compatible recorder) having strong compatibility, for example, a separate and independent optical pickup apparatus is provided for each recording format, and information recording is performed. A method of switching the optical pickup device to be used according to the type of optical disc to be reproduced is also conceivable. However, this method may cause adverse effects such as an increase in manufacturing cost of the information recording / reproducing apparatus and an increase in the size of the apparatus, and cannot be a practical option. From this point of view, conventionally, a light source unit in which a semiconductor laser for CD and a semiconductor laser for DVD are packaged in one package, and a semiconductor laser for a high recording density optical disk (specifically, BD, etc.) The so-called compatible objective lens (that is, an objective lens with different numerical apertures on the inner and outer peripheral sides) is used to support the light beam output from each light source for each recording format. There has been proposed a method of condensing light on an optical disk (see Patent Document 1). Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-281008
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0004] ところで、上記特許文献 1に記載の光ピックアップ装置は、 CD及び DVD用のディ テクタと、高記録密度型光ディスク用のディテクタとが別個に設けられた構成となって いる。このため、この光ピックアップ装置を実際に製造する場合、光ピックアップ内に ディテクタ用の基板を 2つ設け、更に、各基板毎に受光信号を出力するための配線 を設けることが必須となってしまい、光ピックアップ装置自体の小型化が困難となって いた。 By the way, the optical pickup device described in Patent Document 1 has a configuration in which a detector for CD and DVD and a detector for high recording density optical disc are separately provided. For this reason, when actually manufacturing this optical pickup device, it is essential to provide two detector substrates in the optical pickup and to provide a wiring for outputting a light reception signal for each substrate. Therefore, it has been difficult to downsize the optical pickup device itself.
[0005] 本願は、以上説明した事情に鑑みてなされたものであり、その課題の一例としては 、 3つの異なる記録フォーマットに対応した記録媒体に対する情報の記録及び再生 を行 、つつ、小型化を実現することが可能な光ピックアップ装置及び情報記録再生 装置を提供することを目的とする。  [0005] The present application has been made in view of the circumstances described above. As an example of the problem, information can be recorded on and reproduced from a recording medium corresponding to three different recording formats, and downsizing can be performed. An object of the present invention is to provide an optical pickup device and an information recording / reproducing device that can be realized.
課題を解決するための手段  Means for solving the problem
[0006] 上述した課題を解決するため、本願の一つの観点にぉ 、て請求項 1に記載の光ピ ックアップ装置は、各々波長の異なる 3つの光ビームであって、最も波長の短い第 1 光ビームを出力する第 1光源と、前記第 1光ビームよりも波長の長い第 2光ビームを出 力する第 2光源と、前記第 2光ビームよりも波長の長い第 3光ビームを出力する第 3光 源とを備え、前記第 1、第 2及び第 3光ビームを、夫々、記録フォーマットの異なる光 学式記録媒体に集光すると共に、前記第 1、第 2及び第 3光ビームの前記光学式記 録媒体における反射光を、夫々、受光する光ピックアップ装置であって、前記第 1光 源と第 3光源が各々異なる位置に配置されると共に、前記第 2光源が前記第 1光源及 び第 3光源の何れか一方と同一筐体内にユニット化された光ビーム出力手段と、第 1 光路を介して前記第 1光ビームを前記光学式記録媒体に集光させると共に、第 2光 路を介して前記第 3光ビームを前記光学式記録媒体に集光させる一方、前記第 2光 ビームについては前記ユニットィ匕された他の光源からの光ビームと略同一の光路を 介して前記光学式記録媒体に集光させる往路集光手段と、単一のユニットとして構 成され、前記第 1、第 2及び第 3光ビームに対応した前記反射光を受光する受光手段 と、入射光の偏光状態に依存して光を透過させ或いは反射させる光学素子を有し、 前記第 1光路を介して入射される前記反射光を前記受光手段に集光させる第 1復路 集光手段と、入射光の偏光状態に依存することなく一定の割合にて当該光を透過さ せ或いは反射させる光学素子を有し、前記第 2光路を介して入射される前記反射光 を前記受光手段に集光する第 2復路集光手段と、を具備することを特徴とする。 In order to solve the above-described problem, according to one aspect of the present application, the optical pick-up device according to claim 1 includes three light beams each having a different wavelength, and the first one having the shortest wavelength. A first light source that outputs a light beam; a second light source that outputs a second light beam having a longer wavelength than the first light beam; and a third light beam that has a longer wavelength than the second light beam. A first light source, condensing the first, second, and third light beams on optical recording media having different recording formats, respectively, and the first, second, and third light beams. An optical pickup device for receiving reflected light from the optical recording medium, respectively, wherein the first light source and the third light source are arranged at different positions, and the second light source is the first light source. And a light beam output unitized in the same housing as either one of the third light source Force means, and condensing the first light beam on the optical recording medium via a first optical path and condensing the third light beam on the optical recording medium via a second optical path. The second light beam is configured as a single unit, and a forward path condensing means for condensing the optical recording medium through the optical path substantially the same as the light beams from the other light sources unitized. Receiving means for receiving the reflected light corresponding to the first, second and third light beams And an optical element that transmits or reflects the light depending on the polarization state of the incident light, and the first return path for condensing the reflected light incident through the first optical path on the light receiving means. And an optical element that transmits or reflects the light at a certain rate without depending on the polarization state of the incident light, and the reflected light incident through the second optical path is the light receiving means. And second return path condensing means for condensing the light.
[0007] また、本願の他の観点にぉ 、て請求項 5に記載の情報記録再生装置は、請求項 1 乃至請求項 4の何れか一項に記載の光ピックアップ装置と、前記光ピックアップ装置 を駆動する駆動手段と、前記駆動手段を制御することにより、前記光学式記録媒体 に対する情報の記録及び再生を制御する制御手段と、前記光ピックアップ装置にお ける受光結果に対応した信号を出力する出力手段と、を具備することを特徴とする。 図面の簡単な説明  [0007] Further, according to another aspect of the present application, an information recording / reproducing device according to claim 5 includes the optical pickup device according to any one of claims 1 to 4 and the optical pickup device. Driving means for controlling the optical recording medium, control means for controlling recording and reproduction of information on the optical recording medium by controlling the driving means, and a signal corresponding to a light reception result in the optical pickup device is output. Output means. Brief Description of Drawings
[0008] [図 1]実施形態における情報記録再生装置 RPの構成を示すブロック図である。  FIG. 1 is a block diagram showing a configuration of an information recording / reproducing apparatus RP in an embodiment.
[図 2]実施形態に力かるダイクロイツク PSB211の反射特性を示す図である。  FIG. 2 is a diagram showing the reflection characteristics of dichroic PSB211 which is useful for the embodiment.
[図 3]変形例 1にかかるダイクロイツク PSB211の反射特性を示す図である。  FIG. 3 is a diagram showing the reflection characteristics of a dichroic PSB211 according to Modification 1.
[図 4]変形例 2における情報記録再生装置 RP2の構成を示すブロック図である。  FIG. 4 is a block diagram showing a configuration of an information recording / reproducing apparatus RP2 in Modification 2.
[図 5]変形例 3における情報記録再生装置 RP3の構成を示すブロック図である。 符号の説明  FIG. 5 is a block diagram showing a configuration of an information recording / reproducing apparatus RP3 in Modification 3. Explanation of symbols
[0009] RP、 RP2、 RP3 · · ·情報記録再生装置 [0009] RP, RP2, RP3 · · · Information recording and playback device
SP，，，信号処理部  SP ... signal processor
C'，，制御部  C ', control unit
D…駆動回路  D ... Drive circuit
PU、 PU2、 PU3 - - '光ピックアップ装置  PU, PU2, PU3--'Optical pickup device
AS - - 'ァクチユエータサーボ回路  AS--'actuator servo circuit
SS - - 'ステップモータサーボ回路  SS--'Step motor servo circuit
Ρ· · ·再生部  再生 ··· Playback part
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0010] 以下、本願の実施形態について説明することとするが、これに先立って、本願の完 成に至る基本発想について説明する。 <某本発想 > [0010] Hereinafter, embodiments of the present application will be described. Prior to this, basic ideas for completing the present application will be described. <Enomoto idea>
まず、上述したように 3つの異なる記録フォーマットに対応した光ディスクに対するデ ータの記録及び再生を実現しつつ、光ピックアップ装置の小型化を実現するために は、光ピックアップ装置内に搭載するディテクタ数を削減し、ディテクタ数の増加に伴 う、基板や配線の増加を防止することが必要となる。そこで、本願の完成に際しては、 複数光源から出力された光ビームを如何にして一つのディテクタに集光すべきかを 主要観点とし、光学系の設計を行うこととした。  First, as described above, in order to realize data recording and reproduction with respect to an optical disc that supports three different recording formats, and to reduce the size of the optical pickup device, the number of detectors mounted in the optical pickup device Therefore, it is necessary to prevent the increase in the number of substrates and wirings as the number of detectors increases. Therefore, when completing this application, we decided to design the optical system with the main viewpoint of how the light beams output from multiple light sources should be focused on one detector.
[0011] その一方、光ディスクに対する情報の記録再生時における最適な条件は、各記録 フォーマット毎に異なっているため、光学系の設計に際しては、以下の 2つの点を考 慮することが必要となる。すなわち、 <条件 1 > 光ディスクにおける記録密度の向上 を実現するためには、光ディスクに照射される光ビームのエネルギー密度 (すなわち 集光スポットにおけるエネルギー密度）を増力 tlさせる必要があるという点、及びく皿 2> CDのように保護層の厚い光ディスクにおいては、保護層において生じる複屈 折が多くなる可能性が高ぐ光ビームが保護層を透過する際に、この複屈折に起因し て偏光状態に変化が生じる可能性があるという点、である。  [0011] On the other hand, since the optimum conditions for recording / reproducing information with respect to the optical disc are different for each recording format, it is necessary to consider the following two points when designing the optical system. . That is, <Condition 1> In order to improve the recording density of the optical disc, it is necessary to increase the energy density of the light beam irradiated to the optical disc (that is, the energy density at the focused spot), and Plate 2> In an optical disc with a thick protective layer such as a CD, when the light beam that has a high possibility of increasing the number of double refractions in the protective layer is transmitted through the protective layer, the polarization state is caused by this birefringence. There is a possibility that changes may occur.
[0012] カゝかる点を考慮した場合、 BD (すなわち、高記録密度型光ディスク)等に対する情 報の記録及び再生を行う光学系においては、往路 (すなわち、光源から出力された 光ビームを光ディスクに導光する方向）と、復路 (すなわち、光ディスクにおける反射 光をディテクタに導光する方向）の分離素子として、ハーフミラー等のエネルギー損 失の大きい光学素子を用いることなぐ光の偏光状態に応じて透過 Z反射特性を変 化させられる光学素子 (例えば、 PBS :偏光ビームスプリッタ）を用いることが望ましい 。し力しながら、このような光学素子を用いた場合、光ディスクにおける複屈折に起因 して偏光の状態が変化してしまうと、往路及び復路の分離特性が悪化する。従って、 CDのような保護層の厚 、光ディスク用の光学系にお 、ては、光の透過 Z反射特性 に関して偏光依存性を有する光学素子を用いることなぐ例えば、ハーフミラーのよう な偏光依存性のない往路 Z復路分離素子を用いる必要性が生じてくるのである。  [0012] In consideration of the points to be considered, in an optical system for recording and reproducing information on a BD (that is, a high recording density type optical disk) or the like, the optical beam output from the light source Depending on the polarization state of the light without using an optical element having a large energy loss, such as a half mirror, as a separating element for the light guiding direction) and the return path (that is, the direction for guiding the reflected light from the optical disk to the detector). It is desirable to use an optical element (for example, PBS: polarization beam splitter) that can change the transmission Z reflection characteristics. However, when such an optical element is used, if the polarization state changes due to birefringence in the optical disc, the separation characteristics of the forward path and the backward path are deteriorated. Therefore, the thickness of the protective layer, such as CD, and the optical system for optical discs do not use an optical element having polarization dependency with respect to light transmission Z reflection characteristics. There is a need to use the Z-return separation element without a forward path.
[0013] かかる観点から、本願においては、 1ディテクタの構成を踏襲しつつ、 CDのような保 護層の厚 ヽ光ディスク用の光学系と、 BDや HD— DVDと ヽつた高記録密度型光デ イスク用の光学系と、を別個の光路により設計すると共に、（a)保護層の厚い光デイス ク用の光学系については非偏光光学系（具体的には、偏光依存性のある往路 Z復 路分離素子が配置されて!ヽな!ヽ光学系）、 (b)高記録密度型光ディスク用の光学系 につ!、ては偏光光学系 (偏光依存性のある往路 Z復路分離素子を配置した光学系） 、とする構成を採用することとした。 [0013] From this point of view, in the present application, while following the structure of one detector, the optical system for the optical disk for a protective layer such as a CD and the high recording density type light combined with BD and HD-DVD De The optical system for the disk is designed with a separate optical path, and (a) the optical system for the optical disk with a thick protective layer is a non-polarized optical system (specifically, the polarization-dependent forward path Z recovery). (B) optical system for high recording density type optical discs, and polarization optical system (polarization-dependent forward path Z return path separation element is arranged) The optical system) was adopted.
なお、 DVDの場合、光路上におけるエネルギー損失の影響は少なぐまた、光ディ スクにおける複屈折も少ないため、偏光光学系、非偏光光学系の何れを用いても問 題は生じず、何れの光路を用いることも可能となる。以下、上記基本発想に基づく本 願の実施の形態について詳細に説明することとする。  In the case of DVD, the effect of energy loss on the optical path is small, and the birefringence in the optical disk is also small, so there is no problem even if either a polarizing optical system or a non-polarizing optical system is used. It is also possible to use an optical path. Hereinafter, embodiments of the present application based on the above basic idea will be described in detail.
[0014] m m  [0014] m m
[1. Ώ Μ ΜΩΜ^  [1. Ώ Μ ΜΩΜ ^
以下、本実施形態にかかる情報記録再生装置 RPの概要構成を示す図 1を参照し つつ、本実施形態にかかる情報記録再生装置 RPの全体構成及び動作概要にっ 、 て説明する。なお、本実施形態にかかる情報記録再生装置 RPは、 CD、 DVD,更に は、 BDの各記録フォーマットに対応した光ディスク DKに対するデータの記録及び 再生を行うコンパチブルレコーダに、本願の光ピックアップ装置 PUを適用したもので ある。  Hereinafter, the overall configuration and operation outline of the information recording / reproducing apparatus RP according to the present embodiment will be described with reference to FIG. 1 showing the schematic structure of the information recording / reproducing apparatus RP according to the present embodiment. The information recording / reproducing apparatus RP according to the present embodiment includes the optical pickup apparatus PU of the present application as a compatible recorder that records and reproduces data with respect to an optical disc DK corresponding to each recording format of CD, DVD, and BD. It is applied.
[0015] 同図に示すように本実施形態にかかる情報記録再生装置 RPは、大別して信号処 理部 SPと、制御部 Cと、駆動回路 Dと、光ピックアップ装置 PUと、ァクチユエ一タサー ボ回路 ASと、再生部 Pと、により構成される。  As shown in FIG. 1, the information recording / reproducing apparatus RP according to the present embodiment is roughly classified into a signal processing unit SP, a control unit C, a drive circuit D, an optical pickup device PU, and an actuator servo. The circuit AS and the reproducing unit P are included.
[0016] 信号処理部 SPは、入力端子を有しており、この端子を介して外部力 入力された データに信号処理を施して制御部 Cに出力する。この信号処理部 SPにおいて行う具 体的な処理内容については任意であり、例えば、入力されたデータを MPEG (Movin g Picture Experts Group)等の圧縮方式にて圧縮した後、当該データを制御部じに 出力するようにしても良い。  [0016] The signal processing unit SP has an input terminal. The signal processing unit SP performs signal processing on data input through the terminal and outputs the data to the control unit C. Specific processing contents performed in the signal processing unit SP are arbitrary. For example, after the input data is compressed by a compression method such as MPEG (Moving Picture Experts Group), the data is processed by the control unit. You may make it output to.
[0017] 制御部 Cは、主として CPU (Central Processing Unit)により構成され、情報記録 再生装置 RPの各部を制御する。例えば、光ディスク DKに対してデータを記録する 場合、制御部 Cは信号処理部 SPから入力されたデータに対応した記録用の駆動信 号を駆動回路 Dに出力する一方、光ディスク DKに記録されているデータの再生を行 う場合には、再生用の駆動信号を駆動回路 Dに出力する。 [0017] The control unit C is mainly configured by a CPU (Central Processing Unit), and controls each unit of the information recording / reproducing apparatus RP. For example, when data is recorded on the optical disc DK, the control unit C uses a drive signal for recording corresponding to the data input from the signal processing unit SP. When the data recorded on the optical disc DK is to be reproduced, the reproduction drive signal is outputted to the drive circuit D.
[0018] 駆動回路 Dは主として増幅回路により構成され、制御部 C力 入力された駆動信号 を増幅した後、光ピックアップ装置 PUに供給する。この駆動回路 Dにおける増幅率 は制御部 Cにより制御され、光ディスク DKにデータを記録する場合には、光ピックァ ップ装置 PU力 記録パワーにて光ビームが出力されるように増幅率が制御される。 なお、「記録パワー」とは、相変化型の光ディスク DK (例えば、 DVD-RW)及び色素 変色型の光ディスク DK (例えば、 DVD-R)において相変化若しくは色素変色を生じ るエネルギー量を意味する。一方、光ディスク DKに記録されているデータを再生す る場合、光ピックアップ装置 PU力 再生パワー（すなわち、光ディスク DKにおいて色 素変色等の変化が生じないエネルギー量）にて光ビームが出力されるように増幅率 が制御される。 [0018] The drive circuit D is mainly composed of an amplifier circuit, amplifies the drive signal input by the control unit C force, and supplies the amplified drive signal to the optical pickup device PU. The amplification factor in the drive circuit D is controlled by the control unit C. When data is recorded on the optical disc DK, the amplification factor is controlled so that a light beam is output with the optical pickup device PU force recording power. The “Recording power” means the amount of energy that causes phase change or dye discoloration in a phase change type optical disc DK (eg, DVD-RW) and a dye color change type optical disc DK (eg, DVD-R). . On the other hand, when data recorded on the optical disc DK is played back, the optical beam is output with the optical pickup device PU power playback power (that is, the amount of energy that does not cause color change in the optical disc DK). The amplification factor is controlled by this.
[0019] 光ピックアップ装置 PUは、駆動回路 D力 供給される制御信号に基づいて複数の 記録フォーマットに対応した光ディスク DK (すなわち、 BD、 DVD、 CD)に対して光 ビームを照射し、光ディスク DKに対するデータの記録及び読み出しを行うために用 いられる。力かる機能を実現するため、本実施形態にかかる光ピックアップ装置 PU は、大別して、光源部 1と、光学部 2と、受光部 3と、を有している。  [0019] The optical pickup device PU irradiates the optical disc DK (that is, BD, DVD, CD) corresponding to a plurality of recording formats based on the control signal supplied to the drive circuit D force with an optical disc DK. Used to record and read data from In order to realize a powerful function, the optical pickup device PU according to the present embodiment roughly includes a light source unit 1, an optical unit 2, and a light receiving unit 3.
[0020] これらの要素中、光源部 1は、駆動回路 D力 供給される駆動信号に基づいて光ビ ームを出力するための要素である。この光源部 1は、第 1半導体レーザ 11と、第 2半 導体レーザ 12と、第 3半導体レーザ 13と、を備えており、各半導体レーザは、第 1半 導体レーザ 11が BD用、第 2半導体レーザ 12が DVD用、第 3半導体レーザ 13が C D用の光ビームを出力する素子となっている。また、これらの半導体レーザ 11〜13 の内、第 2半導体レーザ 12と第 3半導体レーザ 13は、光源ユニット 10の単一パッケ ージ内に納められており（所謂、 2レーザ 1パッケージ）、この光源ユニット 10内の各レ 一ザ 12及び 13から出力される光ビームは、第 1光源 11から出力される光ビームと異 なる光路を介して出力されるようになっている。換言するならば、この光源部 1におい ては、 CD用の光源と DVD用の光源が 1パッケージとされ、 BD用の光源とは別個の 位置に配置されると共に、 BD用の光ビームと、 CD、 DVD用の光ビームと力 完全に 分離された光路を介して出力されるのである。 [0020] Among these elements, the light source unit 1 is an element for outputting an optical beam based on a drive signal supplied with a drive circuit D force. The light source unit 1 includes a first semiconductor laser 11, a second semiconductor laser 12, and a third semiconductor laser 13. Each semiconductor laser includes a first semiconductor laser 11 for BD, a second semiconductor laser 11, and a second semiconductor laser 13. The semiconductor laser 12 is an element for outputting a DVD and the third semiconductor laser 13 is an element for outputting a CD light beam. Of these semiconductor lasers 11 to 13, the second semiconductor laser 12 and the third semiconductor laser 13 are housed in a single package of the light source unit 10 (so-called two lasers and one package). The light beams output from the lasers 12 and 13 in the light source unit 10 are output via an optical path different from the light beam output from the first light source 11. In other words, in this light source unit 1, the light source for CD and the light source for DVD are made into one package, and the light source for BD is arranged at a position different from the light source for BD, Light beam and power for CD, DVD completely It is output via the separated optical path.
[0021] 次に、光学部 2は、往路 Z復路分離部 21と、第 1コリメータレンズ 22と、第 2コリメ一 タレンズ 23と、 λ Ζ4板 24と、第 1対物レンズ 251及び第 2対物レンズ 252を有するァ クチユエータ部 25と、を有し、光源部 1から出力される光ビームを光ディスク DK上に 集光する。この光学部 2は、（a) BD用の光学系と、（b) CD、 DVD用の光学系とが、 分離されており、第 1半導体レーザ 11力 出射された光ビームについては、第 1対物 レンズ 251〖こ導光され、この第 1対物レンズ 251を透過して光ディスク DKに照射され るようになっている。これに対して、光源ユニット 10の各半導体レーザ 12及び 13から 出力される光ビームは、第 2対物レンズ 252を介して光ディスク DKに照射される。  Next, the optical unit 2 includes an outward Z return path separating unit 21, a first collimator lens 22, a second collimator lens 23, a λ と 4 plate 24, a first objective lens 251 and a second objective lens. And an actuator unit 25 having 252 for focusing the light beam output from the light source unit 1 on the optical disc DK. In this optical unit 2, (a) the optical system for BD and (b) the optical system for CD and DVD are separated from each other. The objective lens 251 is guided and transmitted through the first objective lens 251 to be applied to the optical disc DK. On the other hand, the light beam output from each of the semiconductor lasers 12 and 13 of the light source unit 10 is applied to the optical disc DK via the second objective lens 252.
[0022] かかる機能を実現するための各要素について、以下説明する。  [0022] Each element for realizing such a function will be described below.
[0023] まず、往路 Z復路分離部 21は、ダイクロイツク PBS211と、ハーフミラー 212とを有 し、（a)第 1半導体レーザ 11から出力された光ビームを第 1コリメータレンズ 22に、光 源ユニット 10から出力された光ビームを第 2コリメータレンズ 23に、夫々導光する一 方、（b)各コリメータレンズ 22及び 23からの射出光（すなわち、光ディスク DKからの 反射光)の光路を合成し、受光部 3に導光する。  [0023] First, the forward Z return path separation unit 21 includes a dichroic PBS 211 and a half mirror 212. (a) The light beam output from the first semiconductor laser 11 is transmitted to the first collimator lens 22 as a light source. The light beam output from the unit 10 is guided to the second collimator lens 23, while (b) the optical path of the light emitted from each of the collimator lenses 22 and 23 (that is, the reflected light from the optical disc DK) is synthesized. Then, the light is guided to the light receiving unit 3.
[0024] この往路 Z復路分離部 21を構成するハーフミラー 212は、光源ユニット 10と第 2コ リメータレンズ 23との間の光路上に設けられた CD、 DVD用光学系の往路 Z復路分 離素子である。このハーフミラー 212は、入射される光の偏光状態と無関係に、例え ば、 50%の透過率にて光源ユニット 12から出力された光ビームを透過し、残りの 50 %の光ビームを図において (以下、「図中」という。）上方に反射する。また、第 2コリメ ータレンズ 23から反射光が入射された場合、当該反射光を 50%程度の反射率にて 図中下方に反射する。力かるハーフミラー 212の機能により、本実施形態にかかる光 ピックアップ装置 PUにおいては、 CD、 DVD用の光学系において非偏光光学系が 実現されるようになっている。  [0024] The half mirror 212 that constitutes the forward path Z return path separation unit 21 is configured to separate the outward path Z return path of the optical system for CD and DVD provided on the optical path between the light source unit 10 and the second collimator lens 23. It is an element. This half mirror 212 transmits the light beam output from the light source unit 12 with a transmittance of 50%, for example, regardless of the polarization state of the incident light, and the remaining 50% of the light beam in the figure. (Hereinafter referred to as “in the figure”) Reflected upward. Further, when reflected light is incident from the second collimator lens 23, the reflected light is reflected downward in the figure with a reflectance of about 50%. With the function of the powerful half mirror 212, in the optical pickup apparatus PU according to the present embodiment, a non-polarizing optical system is realized in the optical system for CD and DVD.
[0025] これに対して、ダイクロイツク PBS211は、第 1半導体レーザ 11と第 1コリメータレン ズ 22との間の光路上に設けられた BD光学系の往路 Z復路分離素子であり、光の反 射特性に関して偏光依存性と、波長依存性の双方を有している。このダイクロイツク P BS211における光ビームの反射特性について図 2を参照しつつ説明する。なお、同 図においては、 S偏光された光ビームに関する反射特性を実線にて示すと共に、 P偏 光された光ビームに関する反射特性を点線にて示して 、る。 On the other hand, the dichroic PBS 211 is a forward Z return path separation element of the BD optical system provided on the optical path between the first semiconductor laser 11 and the first collimator lens 22, and is used as a light reflecting element. It has both polarization dependency and wavelength dependency with respect to the radiation characteristics. The light beam reflection characteristics of the dichroic PBS 211 will be described with reference to FIG. The same In the figure, the reflection characteristic for the S-polarized light beam is indicated by a solid line, and the reflection characteristic for the P-polarized light beam is indicated by a dotted line.
[0026] 同図に示すように、このダイクロイツク PBS211は、 P偏光された光ビームを、全波長
Figure imgf000010_0001
、てほぼ全て透過させる性質を有する。これに対して S偏光された光ビーム に対しては、所定波長領域に急峻な透過一反射特性の変化点を有しており、 405η mの波長においては S偏光光ビームのほぼ全てを反射するに対し、 650nm及び 78 Onmの波長においては S偏光光ビームをほぼ全て透過させる特性を有する。この結 果、このダイクロイツク PBS211は、 405nmの波長の光ビームに対して PBSとして機 能し、 BD用の光学系において偏光光学系が実現されるのに対して、 650nm及び 7 80nmの波長を有する光ビームに対しては PBSとして機能せず、ハーフミラー 212に より図中下方に反射された反射光を単に透過させる機能を実現するのみとなる。なお 、図 2に示す偏光特性は、使用する波長領域 A、 A'、 B、 C以外の偏光特性につい ては、一例を示すものであり、これに限定するものではない。 [0026] As shown in the figure, this dichroic PBS211 uses a P-polarized light beam for all wavelengths.
Figure imgf000010_0001
, And has a property of transmitting almost all. On the other hand, an S-polarized light beam has a sharp transmission-reflection characteristic change point in a predetermined wavelength region, and reflects almost all of the S-polarized light beam at a wavelength of 405 η m. On the other hand, at wavelengths of 650 nm and 78 Onm, it has a characteristic of transmitting almost all the S-polarized light beam. As a result, this dichroic PBS 211 functions as a PBS with respect to a light beam with a wavelength of 405 nm, and a polarization optical system is realized in the optical system for BD, whereas wavelengths of 650 nm and 780 nm are realized. It does not function as a PBS with respect to the light beam it has, but only realizes the function of simply transmitting the reflected light reflected downward in the figure by the half mirror 212. Note that the polarization characteristics shown in FIG. 2 are merely examples of polarization characteristics other than the wavelength regions A, A ′, B, and C to be used, and the present invention is not limited to this.
[0027] 力かるダイクロイツク PBS211の機能により、本実施形態にかかる光ピックアップ装 置 PUにおいては、各々異なる光路を解して光ディスク DKに照射された光ビームの 反射光の光路が合成され、単一の受光部 3に向けて出射されることとなる。  [0027] With the function of the powerful dichroic PBS 211, the optical pickup apparatus PU according to the present embodiment combines the optical paths of the reflected light beams of the light beam irradiated to the optical disc DK through different optical paths. The light is emitted toward one light receiving unit 3.
[0028] 次いで、第 1コリメータレンズ 22は、第 1半導体レーザ 11から出射された光ビームの 光路上に配置され、 BD用の光学系を構成する一方、第 2コリメータレンズ 23は、光 源ユニット 10から出射された光ビームの光路上に配置され、 CD及び DVD用の光学 系を構成する。また、 λ Ζ4板 24は、第 1コリメータレンズ 22及び第 2コリメータレンズ 23からの出射光の光路上に設けられ、直線偏光、円偏光間の相互変換を行う。  [0028] Next, the first collimator lens 22 is disposed on the optical path of the light beam emitted from the first semiconductor laser 11, and constitutes an optical system for BD, while the second collimator lens 23 is a light source unit. It is placed on the optical path of the light beam emitted from 10 and constitutes the optical system for CD and DVD. The λ Ζ4 plate 24 is provided on the optical path of the outgoing light from the first collimator lens 22 and the second collimator lens 23, and performs mutual conversion between linearly polarized light and circularly polarized light.
[0029] ァクチユエータ部 25は、第 1対物レンズ 251と、互換対物レンズとして構成された第 2対物レンズ 252と、両対物レンズ 251及び 252が固定される対物レンズホルダ 253 、更には、この対物レンズホルダ 253を一体的に可動させる可動機構 254と、を有し 、ァクチユエータサーボ回路 ASから供給される補正信号に基づ 、て対物レンズの位 置を変更させ、トラッキングサーボ及びフォーカスサーボを実現する。  The actuator unit 25 includes a first objective lens 251, a second objective lens 252 configured as a compatible objective lens, an objective lens holder 253 to which both objective lenses 251 and 252 are fixed, and the objective lens A movable mechanism 254 that integrally moves the holder 253, and based on a correction signal supplied from the actuator servo circuit AS, the position of the objective lens is changed to perform tracking servo and focus servo. Realize.
[0030] 次に、受光部 3は、位置合わせグレーティング 31と、エラー検出レンズ 32と、 OEIC 33と、を有し、光ディスク DKからの反射光を受光し、当該受光結果に応じた受光信 号を出力する。 [0030] Next, the light receiving unit 3 includes an alignment grating 31, an error detection lens 32, and an OEIC 33. The light receiving unit 3 receives reflected light from the optical disc DK, and receives a light reception signal corresponding to the light reception result. Output the number.
[0031] これらの要素中、位置合わせグレーティング 31は、往路 Z復路分離部 21から射出 される反射光の光路上に配置されたグレーティングであり、 OEIC33上における集光 スポット位置を調整するために設けられたものとなっている。なお、この位置合わせグ レーティング 31の具体的な格子構成については任意であり、位置合わせの対象とな る光ビームのみ回折させ、 OEIC33上における集光スポット位置を調整することがで きれば良い。例えば、光ピックアップ装置 PUの製造時に、第 1半導体レーザ 11及び 第 2半導体レーザ 12 (或いは、第 3半導体レーザ 13)について光軸調整を行い、 OE IC33上の集光スポット位置の合わせを行った場合を想定する。この場合、光源ュ- ット 10の取り付け位置は、第 2半導体レーザ 12 (或いは、第 3半導体レーザ 13)を基 準に合わされるため、単一パッケージ内に納められた第 3半導体レーザ 13 (或いは、 第 2半導体レーザ 12)について OEIC33上の集光スポット位置にズレが生じる。この ため、位置合わせグレーティング 31による集光スポット位置の調整が必要となるのは 、第 3半導体レーザ 13 (或いは、第 2半導体レーザ 12)から出力された光ビームに対 応した反射光のみとなるため、位置合わせグレーティング 31は、 780nm (650nm) の光ビームのみ回折させる特性を持たせれば良い。  [0031] Among these elements, the alignment grating 31 is a grating arranged on the optical path of the reflected light emitted from the forward path Z return path separation unit 21, and is provided for adjusting the position of the focused spot on the OEIC 33. It has been made. The specific grating configuration of the alignment grating 31 is arbitrary, and it is sufficient that only the light beam to be aligned can be diffracted and the position of the focused spot on the OEIC 33 can be adjusted. For example, when the optical pickup device PU was manufactured, the optical axis was adjusted for the first semiconductor laser 11 and the second semiconductor laser 12 (or the third semiconductor laser 13), and the focused spot position on the OE IC 33 was adjusted. Assume a case. In this case, since the mounting position of the light source unit 10 is matched with the second semiconductor laser 12 (or the third semiconductor laser 13) as a standard, the third semiconductor laser 13 (within a single package) ( Alternatively, the second semiconductor laser 12) is shifted in the focused spot position on the OEIC 33. For this reason, only the reflected light corresponding to the light beam output from the third semiconductor laser 13 (or the second semiconductor laser 12) needs to be adjusted by the alignment grating 31. Therefore, the alignment grating 31 only needs to have a characteristic of diffracting only a light beam of 780 nm (650 nm).
[0032] エラー検出レンズ 32は、位置合わせグレーティング 31から射出される反射光を OE IC33に集光させる。 OEIC33は、例えば、フォトダイオードにより構成され、エラー検 出レンズ 32から照射される光ビームを受光して、受光信号を制御部 C、再生部 P及び ァクチユエータサーボ回路 ASに出力する。  The error detection lens 32 condenses the reflected light emitted from the alignment grating 31 on the OE IC 33. The OEIC 33 is composed of, for example, a photodiode, receives a light beam emitted from the error detection lens 32, and outputs a light reception signal to the control unit C, the reproduction unit P, and the actuator servo circuit AS.
[0033] 次に、再生部 Pは、例えば、加算回路及び増幅回路を有し、 OEIC33から供給され る受光信号に基づいて再生 RF信号を生成する。そして、再生部 Pは、当該再生 RF 信号に対して所定の信号処理を施した後、出力端子 OUTに出力する。  Next, the reproduction unit P includes, for example, an addition circuit and an amplification circuit, and generates a reproduction RF signal based on the light reception signal supplied from the OEIC 33. Then, the reproducing unit P performs predetermined signal processing on the reproduced RF signal and then outputs it to the output terminal OUT.
[0034] ァクチユエータサーボ回路 ASは、演算回路により構成され、光ピックアップ装置 P Uの OEIC33から供給される受光信号に基づいて補正信号 (具体的にはトラッキング エラー信号及びフォーカスエラー信号)を生成してァクチユエータ部 25に出力する。 この結果、ァクチユエータ部 25においては、当該補正信号に基づいて対物レンズホ ルダ 253の位置が変更されトラッキングサーボ及びフォーカスサーボがなされることと なる。 [0034] The actuator servo circuit AS is composed of an arithmetic circuit, and generates a correction signal (specifically, a tracking error signal and a focus error signal) based on a light reception signal supplied from the OEIC 33 of the optical pickup device PU. And output to the actuator unit 25. As a result, the actuator unit 25 changes the position of the objective lens holder 253 based on the correction signal and performs tracking servo and focus servo. Become.
[0035] なお、トラッキングサーボ及びフォーカスサーボを実現するための具体的な方式に ついては任意である。例えば、トラッキングサーボの方式としては DPP方式 (差動プッ シュプル方式)やへテロダイン方式、更には 3ビーム方式を用いることが可能である。 DPP方式や 3ビーム方式を採用する場合、 OEIC33に対して副ビーム（± 1次光）を 受光するための受光部を設けると共に、第 1半導体レーザ 11及び光源ユニット 10と 光学部 2との間にグレーティングを設け、このグレーティングにより各光源力も射出さ れる光ビームを 3ビーム（0次光及び ± 1次光）とするようにすれば良い。また、フォー カスサーボの方式としては、例えば、非点収差法やスポットサイズ法を採用することが 可能である。非点収差法を採用する場合、検出レンズ 32としてシリンドリカルレンズを 用いる共に OEIC33の受光部を 4分割形状とすれば良ぐスポットサイズ法を採用す る場合には検出レンズ 32にホログラムレンズを用いて OEIC33の受光部を 2分割形 状とすれば良い。  [0035] A specific method for realizing the tracking servo and the focus servo is arbitrary. For example, the tracking servo system can be a DPP system (differential push-pull system), a heterodyne system, or a 3-beam system. When adopting the DPP method or the 3-beam method, the OEIC33 is provided with a light receiving part for receiving the secondary beam (± primary light) and between the first semiconductor laser 11 and the light source unit 10 and the optical part 2. It is only necessary to provide a grating with three light beams (0th order light and ± 1st order light) that are also emitted from the light source power by this grating. As a focus servo system, for example, an astigmatism method or a spot size method can be employed. When the astigmatism method is used, a cylindrical lens is used as the detection lens 32, and when the spot size method is used, where the light receiving part of the OEIC33 should be divided into four parts, a hologram lens is used for the detection lens 32. The light receiving part of OEIC33 should be divided into two.
[0036] [1. 2Ί ¾施形能の動作  [0036] [1. 2Ί ¾Operation of shaping ability
次いで、以上のような構成を有する本実施形態にかかる情報記録再生装置 RPの 具体的な動作について説明することとするが、同情報記録再生装置 RPにおける動 作は、（1) BDを光ディスク DKとして用いた場合と、（2)じ0及び0¥0を光ディスク0 Kとして用いた場合、とで動作内容が異なるため以下においては、両パターンに場合 分けして説明を行うこととする。  Next, the specific operation of the information recording / reproducing apparatus RP according to the present embodiment having the above-described configuration will be described. The operation of the information recording / reproducing apparatus RP is as follows. Therefore, in the following, description will be made separately for both patterns, because the operation contents are different between (2) when 0 and 0 ¥ 0 are used as the optical disc 0K.
[0037] ( 1 ) BDを光ディスク DKとして用 ヽた場合  [0037] (1) When using BD as optical disc DK
情報記録再生装置 RPに対して光ディスク DKとして BDが挿入された場合、図示せ ぬディスク判別回路により挿入された光ディスクが BDであることが検出される。この状 態において、ユーザが図示せぬ操作部に対して当該光ディスク DKに対して情報を 記録し、或いは、再生する旨の入力操作を行う。すると、制御部 Cは、当該入力操作 に応じて駆動回路 Dに対する駆動信号の供給を開始する。この際、当該操作が情報 の記録を指示するものであった場合、制御部 Cは、信号処理部 SPから供給される信 号に対応した駆動信号を駆動回路 Dに供給すると共に駆動回路 Dにおける増幅率 を記録パワーに対応した値に設定する。また、当該操作が情報の再生を指示するも のであった場合、制御部 Cは、再生用の駆動信号を駆動回路 Dに供給すると共に駆 動回路 Dにおける増幅率を再生パワーに対応した値に設定する。 When the BD is inserted as the optical disc DK into the information recording / reproducing apparatus RP, the disc discriminating circuit (not shown) detects that the inserted optical disc is a BD. In this state, the user performs an input operation for recording or reproducing information on the optical disc DK to an operation unit (not shown). Then, the control unit C starts supplying drive signals to the drive circuit D in accordance with the input operation. At this time, if the operation is to instruct recording of information, the control unit C supplies a drive signal corresponding to the signal supplied from the signal processing unit SP to the drive circuit D and also in the drive circuit D. Set the gain to a value corresponding to the recording power. In addition, the operation may instruct the reproduction of information. In this case, the control unit C supplies the driving signal for reproduction to the driving circuit D and sets the amplification factor in the driving circuit D to a value corresponding to the reproducing power.
[0038] このようにして制御部 C力 駆動信号が供給されると駆動回路 Dは、第 1半導体レー ザ 11に対して所定の駆動信号を出力する。この結果、第 1半導体レーザ 11から 405 nmの波長を有する光ビーム (例えば、 P偏光）が出力され、当該光ビームは、ダイク口 イツク PBS211を透過して、第 1コリメータレンズ 22において平行光に変換された後、 λ Ζ4板 24に入射される。次いで、この光ビームは、 λ Ζ4板 24を透過して円偏光の 状態に移行し、第 1対物レンズ 251により光ディスク DKの記録面上に集光される。  When the control unit C force drive signal is supplied in this way, the drive circuit D outputs a predetermined drive signal to the first semiconductor laser 11. As a result, a light beam (for example, P-polarized light) having a wavelength of 405 nm is output from the first semiconductor laser 11, and the light beam is transmitted through the diced mouth PBS PBS 211 and converted into parallel light by the first collimator lens 22. After the conversion, the light enters the λ Ζ4 plate 24. Next, this light beam passes through the λ 4 plate 24 and shifts to a circularly polarized state, and is condensed on the recording surface of the optical disc DK by the first objective lens 251.
[0039] このようにして、光ディスク DKの記録面上に集光された光ビームは、当該記録面に おいて反射され、反射光として第 1対物レンズ 251を透過した後、再度、 λ Ζ4板 24 を透過することにより、往路と π Ζ2だけ偏光方向が変化し、例えば、往路において Ρ 偏光されていた光ビームが復路において S偏光された状態となる。この結果、 λ Ζ4 板 24を透過して偏光方向の変化した反射光は、第 1コリメータレンズ 22を透過した後 に、ダイクロイツク PBS211により図中下方へと反射され、位置合わせグレーティング 31を透過して、エラー検出レンズ 32に入射し、 OEIC33に集光される。  [0039] The light beam condensed on the recording surface of the optical disc DK in this way is reflected on the recording surface, passes through the first objective lens 251 as reflected light, and then again becomes the λ 4 plate By passing through 24, the direction of polarization changes by π 往 2 in the forward path, for example, a light beam that has been polarized in the forward path becomes S-polarized in the return path. As a result, the reflected light whose polarization direction has been changed after passing through the λ 4 plate 24 is transmitted downward through the first collimator lens 22 and then reflected downward by the dichroic PBS 211, and passes through the alignment grating 31. Then, the light enters the error detection lens 32 and is condensed on the OEIC 33.
[0040] 一方、このようにして集光された反射光を受光すると、 OEIC33は、当該反射光に 対応した受光信号を再生部 Ρや制御部 C、更には、ァクチユエータサーボ回路 ASに 出力する。この結果、例えば、再生時には再生部 Pから光ディスクに記録された情報 に対応する信号が出力される。また、例えば、制御部 Cにより駆動回路 Dの増幅率が 制御され第 1半導体レーザ 11から出力される光ビームの光量が制御されると共に、 ァクチユエータサーボ回路 ASによってァクチユエータ部 25が駆動されてトラッキング 及びフォーカスの各サーボが実現されることとなる。  [0040] On the other hand, when the reflected light collected in this way is received, the OEIC 33 sends the received light signal corresponding to the reflected light to the reproduction unit 制 御, the control unit C, and further to the actuator servo circuit AS. Output. As a result, for example, a signal corresponding to the information recorded on the optical disc is output from the playback unit P during playback. Further, for example, the control unit C controls the amplification factor of the drive circuit D to control the amount of light beam output from the first semiconductor laser 11, and the actuator servo circuit AS drives the actuator unit 25. Thus, tracking and focus servos are realized.
[0041] ( 2) CD及び DVDを光ディスク DKとして用 ヽた場合  [0041] (2) When using CD and DVD as optical disc DK
一方、情報の記録再生対象となる光ディスク DKが CD若しくは DVDである場合、 駆動回路 Dは、制御部 C力も供給される駆動信号に基づいて光源ユニット 10の第 2 半導体レーザ 12或いは第 3半導体レーザ 13に対して所定の駆動信号を出力する。 この結果、光源ユニット 10から 650nm或いは 780nmの波長を有する光ビーム（例え ば、 P偏光）が射出され、当該光ビームは、ハーフミラー 212を、例えば、 50%程度の 透過率で透過した後、第 2コリメータレンズ 23へと入射される。そして、この光ビーム は、第 2コリメータレンズ 23により平行光に変換された後、 λ Ζ4板 24を透過して円 偏光の状態に移行し、第 2対物レンズ 252により光ディスク DKの記録面上に集光さ れる。 On the other hand, when the optical disc DK to be recorded / reproduced with information is a CD or DVD, the drive circuit D uses the second semiconductor laser 12 or the third semiconductor laser of the light source unit 10 based on the drive signal to which the control unit C force is also supplied. A predetermined drive signal is output to 13. As a result, a light beam (for example, P-polarized light) having a wavelength of 650 nm or 780 nm is emitted from the light source unit 10, and the light beam passes through the half mirror 212, for example, about 50%. After being transmitted at the transmittance, the light enters the second collimator lens 23. Then, this light beam is converted into parallel light by the second collimator lens 23, then passes through the λ 板 4 plate 24 and shifts to a circularly polarized state, and is transferred onto the recording surface of the optical disc DK by the second objective lens 252. It is condensed.
[0042] このようにして、光ディスク DKの記録面上に照射された光ビームは、当該記録面に おいて反射され、反射光として第 2対物レンズ 252を透過した後、 λ Ζ4板 24を透過 する。この結果、当該反射光は、往路と π Ζ2だけ偏光方向が変化した直線偏光を 中心とし、光ディスク DKの持つ複屈折量に応じた楕円偏光の状態に移行する（なお 、 DVDの場合、複屈折による影響は小さい)。次いで、この反射光は、第 2コリメータ レンズ 23を透過して、ハーフミラー 212において光ディスク DKの持つ複屈折量の大 小にかかわらずに 50%程度の反射率 (すなわち、光源ユ ット 10からの出力光量に 対して 25%程度の光量）にて図中下方へと反射される。この結果、この反射光は、ダ ィクロイツク PBS211を透過して、位置合わせグレーティング 31に入射され、位置合 わせグレーティング 31においてグレーティングの特性に応じて当該反射光が回折さ れる。  [0042] In this way, the light beam irradiated on the recording surface of the optical disc DK is reflected on the recording surface, passes through the second objective lens 252 as reflected light, and then passes through the λΖ4 plate 24. To do. As a result, the reflected light shifts to an elliptically polarized state according to the amount of birefringence of the optical disc DK, centering on the linearly polarized light whose polarization direction has changed by πΖ2 in the forward path (in the case of DVD, birefringence Is less affected). The reflected light then passes through the second collimator lens 23, and has a reflectance of about 50% (that is, from the light source unit 10) regardless of the amount of birefringence of the optical disk DK in the half mirror 212. Is reflected downwards in the figure). As a result, the reflected light passes through the dichroic PBS 211 and is incident on the alignment grating 31. The alignment grating 31 diffracts the reflected light in accordance with the characteristics of the grating.
[0043] 次いで、この位置合わせグレーティング 31からの射出光は、エラー検出レンズ 32に より、 OEIC33に集光される。この結果、当該反射光が OEIC33により受光されて、ト ラッキングサーボ等が実現されることとなる。  Next, the light emitted from the alignment grating 31 is condensed on the OEIC 33 by the error detection lens 32. As a result, the reflected light is received by the OEIC 33, and a tracking servo or the like is realized.
[0044] このようにして、本実施形態に力かる光ピックアップ装置 PUにおいては、光源部 1 に第 1半導体レーザ 11と、 2レーザ 1パッケージとなった光源ユニット 10とを設けると 共に、（i) BD用の光学系と、（ii) CD、 DVD用の光学系を別個に設け、更に、往路 Z 復路分離部 21に (i)偏光依存性の無!、ノ、一フミラー 212と、 (ii)偏光依存性及び波 長依存性のあるダイクロイツク PBS211とを設けて、単一の OEIC33に反射光を集光 させる構成となっている。この構成により、第 1〜第 3半導体レーザ 11〜13から出力 された光ビームの反射光が全て、 OEIC33に集光されることとなり、 3つの異なる記録 フォーマットに対応した記録媒体に対する情報の記録及び再生を行!、つつ、光ピッ クアップ装置の小型化を実現することが可能となる。また、上記構成によれば、 BD用 の光学系については偏光光学系、 CD、 DVD用の光学系については非偏光光学系 となるため、各記録フォーマット毎に最適な条件下において光ディスク DKに対する データの記録及び再生を行うことが可能となる。 In this manner, in the optical pickup device PU that is effective in the present embodiment, the light source unit 1 is provided with the first semiconductor laser 11 and the light source unit 10 having two lasers and one package, and (i ) An optical system for BD and (ii) an optical system for CD and DVD are provided separately, and further, (i) no polarization dependence, no, one mirror 212 and ( ii) A polarization-dependent and wavelength-dependent dichroic PBS 211 is provided to collect the reflected light on a single OEIC 33. With this configuration, the reflected light of the light beams output from the first to third semiconductor lasers 11 to 13 are all focused on the OEIC 33, and information can be recorded on recording media corresponding to three different recording formats. It is possible to reduce the size of the optical pickup device while performing reproduction! Further, according to the above configuration, the optical system for BD is a polarization optical system, and the optical system for CD and DVD is a non-polarization optical system. Therefore, it is possible to record and reproduce data on the optical disc DK under optimum conditions for each recording format.
[0045] また、本実施形態においては、波長 405nmの光ビームに対して PBSとして機能す る一方、波長 650nm及び 780nmの光ビームに対しては単純な透過特性を有するダ ィクロイツク PBS211を用いて往路 Z復路を分離する構成として 、るため、装置内に 複雑な構成を設けることなぐ往路 Z復路の分離を行うことが可能となり装置の小型 化を実現することが可能となる。  In the present embodiment, the PBS 511 functions as a PBS with respect to a light beam with a wavelength of 405 nm, while the dichroic PBS 211 having simple transmission characteristics is used with respect to the light beams with a wavelength of 650 nm and 780 nm. Since the Z return path is separated, the outbound Z return path can be separated without providing a complicated configuration in the apparatus, and the apparatus can be downsized.
[0046] なお、上記実施形態においては、 BD、 DVD及び CDのコンパチブルレコーダを実 現する場合を例に説明を行った力 例えば、 HD-DVD, DVD及び CDのコンパチ ブルプレーヤ等、記録フォーマットの異なる各種光ディスク DKに対する情報の記録 及び再生を行う情報記録再生装置 RPについても、上記実施形態と同様の構成によ り実現することが可能である。  [0046] In the above embodiment, the power described in the case of realizing a BD, DVD, and CD compatible recorder is taken as an example. For example, the recording format of HD-DVD, DVD, and CD compatible players, etc. An information recording / reproducing apparatus RP that records and reproduces information on various different optical discs DK can also be realized by the same configuration as that of the above embodiment.
[0047] また、上記実施形態においては、位置合わせグレーティング 31を用いて、 OEIC3 3における集光スポット位置の調整を行う場合を例に説明を行った。しかし、この位置 合わせグレーティング 31は、必ずしも必要とはならず、例えば、 OEIC33の受光部の 分割形状を工夫することによつても同様の受光形態を実現することが可能である。こ の場合、光軸合わせ後における OEIC33上の集光スポット位置を予め実験的に求め 、当該位置に受光部を設けるようにすれば良い。  In the embodiment described above, the case where the focusing spot position in the OEIC 33 is adjusted using the alignment grating 31 has been described as an example. However, the alignment grating 31 is not necessarily required. For example, a similar light receiving mode can be realized by devising the divided shape of the light receiving portion of the OEIC 33. In this case, the position of the focused spot on the OEIC 33 after the alignment of the optical axis is experimentally obtained in advance, and a light receiving portion is provided at that position.
[0048] また更に、上記実施形態にかかる情報記録再生装置 RPにおいては、制御部 C及 び駆動回路 Dを光ピックアップ装置 PUと別体の装置 (例えば、 CPU)により構成した 例について説明した力 これらは光ピックアップ装置 PUと一体的に構成するようにし ても良い。  [0048] Furthermore, in the information recording / reproducing apparatus RP according to the above-described embodiment, the force described in the example in which the control unit C and the drive circuit D are configured by a device (eg, CPU) separate from the optical pickup device PU. These may be configured integrally with the optical pickup device PU.
[0049] [1. 3Ί実施形態の栾形例  [0049] [1. 3 栾 Embodiment Example
(1)麵列 1  (1) Row 1
上記実施形態においては、第 2半導体レーザ 12と、第 3半導体レーザ 13とを、光 源ユニット 10内にパッケージングし、 DVD用の光学系を非偏光光学系として設計し た構成例について説明した。しかし、上述のように、 DVD用の光学系については、 偏光光学系を採用することも可能である。この場合、第 1半導体レーザ 11及び第 2半 導体レーザ 12を 1パッケージとして光源ユニットを構成するようにすれば良い。 In the above embodiment, the configuration example in which the second semiconductor laser 12 and the third semiconductor laser 13 are packaged in the light source unit 10 and the DVD optical system is designed as a non-polarizing optical system has been described. . However, as described above, a polarizing optical system can be adopted for the DVD optical system. In this case, the first semiconductor laser 11 and the second semiconductor laser 11 The light source unit may be configured with the conductor laser 12 as one package.
[0050] また、この構成を採用する場合、ダイクロイツク PBS211を用いて 405nm及び 650 nmの光ビームの往路 Z復路の分離を行うことが必要となり、ダイクロイツク PBS211 の反射特性を変更することが必要となる。この構成を採用した場合における、ダイク口 イツク PBS211の反射特性を図 3に示す。なお、同図においては、 S偏光された光ビ ームに関する反射特性を実線にて示すと共に、 P偏光された光ビームに関する反射 特性を点線にて示して 、る。 [0050] When this configuration is adopted, it is necessary to separate the forward Z return path of the 405 nm and 650 nm light beams using the dichroic PBS 211, and it is necessary to change the reflection characteristics of the dichroic PBS 211. It becomes. Figure 3 shows the reflection characteristics of the Dyke mouth PBS211 when this configuration is adopted. In the figure, the reflection characteristic for the S-polarized light beam is indicated by a solid line, and the reflection characteristic for the P-polarized light beam is indicated by a dotted line.
[0051] 同図に示すように、この場合においても、ダイクロイツク PBS211の反射特性として は P偏光された光ビームを全波長領域にぉ 、てほぼ全て透過させるようにすることが 必要となる。一方、 S偏光された光ビームに対しては、例えば、 700nm近傍に急峻な 透過—反射特性の変化点を設けるようにし、 405nm及び 650nmの波長においては S偏光光ビームのほぼ全てを反射するに対し、 780nmの波長においては S偏光光ビ ームをほぼ全て透過させる特性を持たせることが必要となる。カゝかる特性を持たせる ことにより、 405nm及び 650nmの波長の光ビームに対してダイクロイツク PBS211を PBSとして機能させ、 780nmの波長を有する光ビームに対しては単純な透過特性を 持たせることが可能となる。 [0051] As shown in the figure, even in this case, it is necessary for the dichroic PBS 211 to reflect almost all of the P-polarized light beam over the entire wavelength region. On the other hand, for an S-polarized light beam, for example, a sharp transmission-reflection characteristic change point is provided in the vicinity of 700 nm, and almost all of the S-polarized light beam is reflected at wavelengths of 405 nm and 650 nm. On the other hand, at the wavelength of 780 nm, it is necessary to have a characteristic of transmitting almost all the S-polarized light beam. By providing a lucrative characteristic, dichroic PBS211 can function as a PBS for light beams with wavelengths of 405 nm and 650 nm, and a simple transmission characteristic can be given for light beams with a wavelength of 780 nm. It becomes possible.
[0052] この結果、本変形例に力かる光ピックアップ装置 PUにおいては、（a)第 1半導体レ 一ザ 11及び第 2半導体レーザ 12がノ ッケージングされた光源ユニットから出力され た光ビームが第 1コリメータレンズ 22に、第 3半導体レーザ 13から出力された光ビー ムが第 2コリメータレンズ 23に、夫々照射される一方、（b)各コリメータレンズ 22及び 2 3からの射出光 (すなわち、光ディスク DKからの反射光）が全て受光部 3に導光され ることとなる。 As a result, in the optical pickup device PU that is effective in this modification, ( a ) the light beam output from the light source unit in which the first semiconductor laser 11 and the second semiconductor laser 12 are knocked is the first. The collimator lens 22 is irradiated with the light beam output from the third semiconductor laser 13 to the second collimator lens 23, respectively, while (b) the light emitted from the collimator lenses 22 and 23 (that is, the optical disk). All the light reflected from the DK is guided to the light receiver 3.
[0053] このようにして、本変形例に力かる光ピックアップ装置 PUによれば、 BD用の第 1半 導体レーザ 11と、 DVD用の第 2半導体レーザ 12とを 1パッケージにした場合であつ ても、上記実施形態と同様に、単一の OEIC33に反射光を集光させることが可能とな る。この結果、 3つの異なる記録フォーマットに対応した記録媒体に対する情報の記 録及び再生を行 、つつ、光ピックアップ装置の小型化を実現することが可能となると 共に、 BD、 DVD用の光学系については偏光光学系、 CD用の光学系については非 偏光光学系とし、各記録フォーマット毎に最適な条件下において光ディスク DKに対 するデータの記録及び再生を行うことが可能となる。 In this way, according to the optical pickup device PU that is effective in the present modification, the first semiconductor laser 11 for BD and the second semiconductor laser 12 for DVD are combined into one package. However, similar to the above embodiment, the reflected light can be collected on a single OEIC 33. As a result, information can be recorded on and reproduced from recording media that support three different recording formats, while miniaturization of the optical pickup device can be realized, and the optical system for BD and DVD can be realized. Non-polarization optics and CD optics With a polarization optical system, data can be recorded on and reproduced from the optical disc DK under optimum conditions for each recording format.
[0054] (2)変形例 2  [0054] (2) Modification 2
上記実施形態においては、 BD用の光学系に対して、単に第 1コリメータレンズ 22 を設けた構成を採用していた。しかし、 BDフォーマットのような高記録密度を実現し た光ディスク DKにおいては、対物レンズの開口数を大きくし、集光スポットの絞り込 みを行う必要性が高いため、保護層の厚み誤差に起因して発生する球面収差や、光 ディスク DKの傾きに起因するコマ収差を適切に補正することが必要となる。  In the above embodiment, a configuration in which the first collimator lens 22 is simply provided for the BD optical system is employed. However, in the optical disc DK that achieves a high recording density such as the BD format, it is highly necessary to increase the numerical aperture of the objective lens and narrow down the focused spot. Therefore, it is necessary to appropriately correct the spherical aberration that occurs and the coma caused by the tilt of the optical disc DK.
[0055] そこで、本変形例に力かる情報記録再生装置 RP2にお 、ては、光ピックアップ装置 PU2の BD用光学系に対して球面収差を補正するための収差補正機構 220を設け た構成を採用することとした。本変形例にかかる情報記録再生装置 RP2の構成を示 すブロック図を図 4に示す。なお、同図において、上記図 1と同様の要素については 同様の符号を付してある。  [0055] Therefore, the information recording / reproducing apparatus RP2 that is effective in the present modification has a configuration in which an aberration correction mechanism 220 for correcting spherical aberration is provided for the BD optical system of the optical pickup apparatus PU2. I decided to adopt it. A block diagram showing the configuration of the information recording / reproducing apparatus RP2 according to this modification is shown in FIG. In the figure, elements similar to those in FIG. 1 are given the same reference numerals.
[0056] 同図に示すように本変形例に力かる光ピックアップ装置 PU2は、第 1コリメータレン ズ 22を含む収差補正機構 220を有している。この収差補正機構 220は、光源側から 入射される光ビーム及び光ディスク DKからの反射光に対して収差補正を行うために 設けられた要素であり、第 1コリメータレンズ 22と、このコリメータレンズ 22を固定する ためのレンズホルダ 222と、ステップモータ 223と、を有している。この収差補正機構 220を構成するレンズホルダ 222は、主軸 224及び副軸 225により光軸方向に対し て平行移動可能な状態にて支持されており、ステップモータサーボ回路 SSから供給 される駆動信号に基づいてステップモータ 223が回転駆動されるのに伴いレンズホ ルダ 222が光軸方向に平行移動するように構成されて 、る。力かる機構に基づきコリ メータレンズ 22が移動し、コリメータレンズ 22の射出光、すなわち、第 1対物レンズ 18 1および第 2対物レンズ 182の入射光が拡散、収束することにより収差補正機能が実 現される。  As shown in the figure, the optical pickup device PU 2 that works well with this modification has an aberration correction mechanism 220 including a first collimator lens 22. The aberration correction mechanism 220 is an element provided for correcting aberrations with respect to the light beam incident from the light source side and the reflected light from the optical disc DK, and includes the first collimator lens 22 and the collimator lens 22. A lens holder 222 for fixing and a step motor 223 are provided. The lens holder 222 constituting the aberration correction mechanism 220 is supported by the main shaft 224 and the sub shaft 225 so as to be movable in parallel with respect to the optical axis direction, and is used as a drive signal supplied from the step motor servo circuit SS. Based on this, the lens holder 222 is configured to translate in the optical axis direction as the step motor 223 is rotationally driven. The collimator lens 22 moves based on the force applied, and the aberration correction function is realized by the diffusion and convergence of the light emitted from the collimator lens 22, that is, the incident light from the first objective lens 181 and the second objective lens 182. Is done.
[0057] ステップモータサーボ回路 SSは、図示せぬ演算回路や記録メモリにより構成され、 センサ SEに設けられた各種センサ (例えば、コリメータ 151の位置情報や初期位置 を検出する位置センサ）、 OEIC33や信号処理部 SPから供給される球面収差補正を 行うために必要な信号 (例えば、エンベロープ信号や球面収差エラー信号、ジッター 等）に基づいてステップモータ 223を駆動する。力かるステップモータサーボ回路 SS の機能により、本実施形態に力かる情報記録再生装置 RP2においては、光ピックァ ップ装置 PU2の光路上において発生する収差の補正が実現される。 [0057] The step motor servo circuit SS is composed of an arithmetic circuit and a recording memory (not shown). Various sensors (for example, a position sensor for detecting the position information and initial position of the collimator 151) provided in the sensor SE, OEIC33, Spherical aberration correction supplied from the signal processor SP The step motor 223 is driven on the basis of a signal necessary for performing (for example, an envelope signal, a spherical aberration error signal, jitter, etc.). By the function of the powerful step motor servo circuit SS, the information recording / reproducing apparatus RP2 that is effective in the present embodiment can correct aberrations that occur on the optical path of the optical pick-up apparatus PU2.
[0058] なお、このステップモータサーボ回路 SSが実際にステップモータ 223を駆動する際 に採用する方法については任意であり、例えば、センサ SEからの検出信号値及びェ ンべロープ信号の信号値に対応する補正量を図示せぬメモリ上にテーブル化して保 持させ、このテーブルに基づ!/、てステップモータ 223を駆動するようにしても良!、。 [0058] It should be noted that the method employed when the step motor servo circuit SS actually drives the step motor 223 is arbitrary. For example, the detection signal value from the sensor SE and the signal value of the envelope signal are used. The corresponding correction amount may be stored in a table on a memory (not shown) and the step motor 223 may be driven based on this table!
[0059] このようにして、本変形例に力かる情報記録再生装置 RP2は、収差補正機構 220 を設け、この収差補正機構 220をステップモータサーボ回路 SSにより駆動する構成 を採用しているため、 BDフォーマットのように開口数の大きなレンズを用いて集光ス ポットの絞り込みを行うことが必要となる場合であっても、球面収差、或いは、色収差 等に起因する収差を補正することが可能となり、もって、光ディスク DKに対する情報 の記録再生時におけるエラー出現確率を効果的に低下させることが可能となる。 [0059] In this way, the information recording / reproducing apparatus RP2 that is effective in the present modification employs a configuration in which the aberration correction mechanism 220 is provided and this aberration correction mechanism 220 is driven by the step motor servo circuit SS. Even when it is necessary to narrow down the condensing spot using a lens with a large numerical aperture as in the BD format, it becomes possible to correct aberrations due to spherical aberration or chromatic aberration. Therefore, it is possible to effectively reduce the error appearance probability at the time of recording / reproducing information with respect to the optical disc DK.
[0060] なお、上記変形例においては、コリメータレンズを移動させることにより収差補正を 実現する構成が採用されていたが、例えば、ビームエキスパンダを用い、或いは、液 晶パネルにより構成された収差補正素子を用いて、同様の機能を実現することが可 能である。なおビームエキスパンダを用いた収差補正機構の構成例については、例 えば、特開 2002— 170274号公報に記載された構成と同様であり、液晶素子を用 いた場合における具体的な収差補正の方法に関しては特開 2002— 358690号公 報に記載された構成と同様であるため詳細は省略する。 In the above-described modification, a configuration in which aberration correction is realized by moving the collimator lens is employed. However, for example, aberration correction using a beam expander or a liquid crystal panel is used. A similar function can be realized using an element. The configuration example of the aberration correction mechanism using the beam expander is similar to the configuration described in, for example, Japanese Patent Application Laid-Open No. 2002-170274, and a specific method for correcting aberration when a liquid crystal element is used. Since the configuration is the same as that described in Japanese Patent Laid-Open No. 2002-358690, the details are omitted.
[0061] (3)変形例 3 [0061] (3) Modification 3
上記実施形態においては、 BD用の光学系に第 1コリメータレンズ 22及び第 1対物 レンズ 251を設けると共に、 CD及び DVD用の光学系に第 2コリメータレンズ 23及び 第 2対物レンズ 252を設けた構成を採用していた。しかし、単一のコリメータレンズ及 び単一の対物レンズを用いた構成により上記実施形態と同様の機能を実現すること も可能である。力かる構成を採用した本変形例に力かる情報記録再生装置 RP3の構 成を図 5に示す。なお、同図において、上記図 1及び図 4と同様の要素については同 様の符号を付してある。 In the above embodiment, the first collimator lens 22 and the first objective lens 251 are provided in the optical system for BD, and the second collimator lens 23 and the second objective lens 252 are provided in the optical system for CD and DVD. Was adopted. However, the same function as that of the above-described embodiment can be realized by a configuration using a single collimator lens and a single objective lens. Figure 5 shows the configuration of the information recording / reproducing device RP3 that employs this powerful configuration. In the figure, the same elements as in FIGS. 1 and 4 are the same. Like symbols are attached.
[0062] 同図に示すように、本変形例に力かるァクチユエータ部 250には、 BD、 DVD及 C Dの 3記録フォーマットに対応した開口数を有する互換対物レンズ 2501が設けられ、 この互換対物レンズ 2501は、対物レンズホルダ 2502に固定されて、可動機構 250 3により可動されるようになって!/、る。  [0062] As shown in the figure, the actuator unit 250, which is effective in this modification, is provided with a compatible objective lens 2501 having a numerical aperture corresponding to three recording formats of BD, DVD and CD. This compatible objective lens 2501 is fixed to the objective lens holder 2502 and can be moved by the movable mechanism 2503.
[0063] また、単一のコリメータレンズ 221は、レンズホルダ 222に固定され、このレンズホル ダ 222は、上記変形例 2と同様にステップモータ 223により光軸方向に対して平行に 移動されるようにされて 、る。  [0063] Further, the single collimator lens 221 is fixed to the lens holder 222, and this lens holder 222 is moved in parallel to the optical axis direction by the step motor 223 as in the second modification. It has been.
[0064] 一方、このように、単一のコリメータレンズ 221及び互換対物レンズ 2501を用いよう とする場合、第 1半導体レーザ 11及び光源ユニット 10から出射された光ビームを如 何にして、単一のコリメータレンズ 221に入射させるかが問題となる。そこで、本変形 例においては、光路合成部 210を設けることとした。この光路合成部 210は、第 1半 導体レーザ 11から出射される光ビームの光路上に設けられたミラー 2101と、光源ュ ニット 10から出射される光ビームの光路上に設けられ、波長 405nmの光ビームを反 射する一方、波長 650nm及び 780nmの光ビームを透過させるダイクロイツクミラー 2 102とを有して!/ヽる。  [0064] On the other hand, when the single collimator lens 221 and the compatible objective lens 2501 are to be used in this way, the light beams emitted from the first semiconductor laser 11 and the light source unit 10 can be used in a single way. The problem is whether it is incident on the collimator lens 221. Therefore, in this modification, the optical path combining unit 210 is provided. This optical path combining unit 210 is provided on the optical path of the light beam emitted from the light source unit 10 and the mirror 2101 provided on the optical path of the light beam emitted from the first semiconductor laser 11, and has a wavelength of 405 nm. It has a dichroic mirror 2102 that reflects a light beam while transmitting a light beam having a wavelength of 650 nm and 780 nm.
[0065] 力かる光路合成部 210の機能により、第 1半導体レーザ 11から出力された光ビーム は、ダイクロイツク PBS211を透過した後、ミラー 2101により図中上方に反射され、ダ ィクロイツクミラー 2102により、図中右方へと反射されて、コリメータレンズ 221に入射 されることとなる。また、当該光ビームの光ディスク DKにおける反射光は、コリメ一タレ ンズ 221を介してダイクロイツクミラー 2102により図中下方に反射された後、ミラー 21 01により図中左方に反射され、更に、ダイクロイツク PBS211により図中下方に反射 されて、受光部 3に導光されることとなる。  The optical beam output from the first semiconductor laser 11 is transmitted through the dichroic PBS 211 by the function of the optical path synthesizing unit 210, and is reflected upward by the mirror 2101 in the figure, so that the dichroic mirror 2102 As a result, the light is reflected to the right in the figure and is incident on the collimator lens 221. The reflected light of the light beam on the optical disk DK is reflected downward by the dichroic mirror 2102 through the collimator lens 221, then reflected leftward by the mirror 2101, and further dichroic. It is reflected downward in the figure by the PBS PBS 211 and guided to the light receiving unit 3.
[0066] 一方、光源ユニット 10から出力された光ビームは、リレーレンズ 200によりビーム径 が調整された後、ハーフミラー 212及びダイクロイツクミラー 2102を透過してコリメ一 タレンズ 221に入射される。そして、当該光ビームの光ディスク DKにおける反射光は 、ダイクロイツクミラー 2102を透過して、ハーフミラー 212において図中下方に反射さ れ、ダイクロイツク PBS211を透過して受光部 3に導光されることとなる。 このようにして、本変形例に力かる情報記録再生装置 RP3によれば、単一のコリメ ータレンズ 221及び互換対物レンズ 2501を利用しつつ、 3つの記録フォーマットに 対応した光ディスク DKに対する情報の記録再生を行うことが可能となり、光ピックアツ プ装置 PU3の更なる小型化を実現することが可能となる。 On the other hand, after the beam diameter is adjusted by the relay lens 200, the light beam output from the light source unit 10 passes through the half mirror 212 and the dichroic mirror 2102 and enters the collimator lens 221. Then, the reflected light of the optical beam on the optical disk DK is transmitted through the dichroic mirror 2102, reflected downward in the drawing by the half mirror 212, and transmitted through the dichroic PBS 211 to be guided to the light receiving unit 3. It becomes. In this way, according to the information recording / reproducing apparatus RP3, which is effective in this modification, information is recorded / reproduced with respect to the optical disc DK corresponding to the three recording formats while using the single collimator lens 221 and the compatible objective lens 2501. This makes it possible to further reduce the size of the optical pick-up device PU3.

Claims

請求の範囲 The scope of the claims
[1] 各々波長の異なる 3つの光ビームであって、最も波長の短い第 1光ビームを出力す る第 1光源と、前記第 1光ビームよりも波長の長い第 2光ビームを出力する第 2光源と 、前記第 2光ビームよりも波長の長い第 3光ビームを出力する第 3光源とを備え、前記 第 1、第 2及び第 3光ビームを、夫々、記録フォーマットの異なる光学式記録媒体に集 光すると共に、前記第 1、第 2及び第 3光ビームの前記光学式記録媒体における反射 光を、夫々、受光する光ピックアップ装置であって、  [1] A first light source that outputs three light beams each having a different wavelength, the first light beam having the shortest wavelength, and a second light beam that outputs a second light beam having a longer wavelength than the first light beam. Two light sources and a third light source that outputs a third light beam having a wavelength longer than that of the second light beam, and the first, second, and third light beams are respectively optically recorded in different recording formats. An optical pickup device that collects light on a medium and receives reflected light of the first, second, and third light beams from the optical recording medium, respectively.
前記第 1光源と第 3光源が各々異なる位置に配置されると共に、前記第 2光源が前 記第 1光源及び第 3光源の何れか一方と同一筐体内にユニット化された光ビーム出 力手段と、  A light beam output means in which the first light source and the third light source are arranged at different positions, and the second light source is unitized in the same housing as either the first light source or the third light source. When,
第 1光路を介して前記第 1光ビームを前記光学式記録媒体に集光させると共に、第 2光路を介して前記第 3光ビームを前記光学式記録媒体に集光させる一方、前記第 2光ビームについては前記ユニットィ匕された他の光源からの光ビームと略同一の光路 を介して前記光学式記録媒体に集光させる往路集光手段と、  The first light beam is condensed on the optical recording medium via the first optical path, and the third light beam is condensed on the optical recording medium via the second optical path, while the second light is condensed. Concerning the beam, forward path condensing means for condensing on the optical recording medium through substantially the same optical path as the light beam from the other unitized light source,
単一のユニットとして構成され、前記第 1、第 2及び第 3光ビームに対応した前記反 射光を受光する受光手段と、  A light receiving means configured as a single unit for receiving the reflected light corresponding to the first, second and third light beams;
入射光の偏光状態に依存して光を透過させ或いは反射させる光学素子を有し、前 記第 1光路を介して入射される前記反射光を前記受光手段に集光させる第 1復路集 光手段と、  First return path light collecting means having an optical element that transmits or reflects light depending on the polarization state of incident light, and that focuses the reflected light incident through the first optical path on the light receiving means. When,
入射光の偏光状態に依存することなく一定の割合にて当該光を透過させ或 、は反 射させる光学素子を有し、前記第 2光路を介して入射される前記反射光を前記受光 手段に集光する第 2復路集光手段と、  An optical element that transmits or reflects the light at a constant rate without depending on the polarization state of the incident light, and reflects the reflected light incident through the second optical path to the light receiving means. A second return path condensing means for condensing;
を具備することを特徴とする光ピックアップ装置。  An optical pickup device comprising:
[2] 前記第 1復路集光手段は、少なくとも前記第 1光ビームについては偏光状態に応じ て反射或 、は透過させる一方、前記第 3光ビームにつ 、ては偏光状態に依存するこ となく透過させる光学素子であることを特徴とする請求項 1に記載の光ピックアップ装 置。 [2] The first return path condensing means reflects or transmits at least the first light beam according to the polarization state, and depends on the polarization state for the third light beam. The optical pickup device according to claim 1, wherein the optical pickup device is an optical element that transmits light without any problem.
[3] 前記光路上に配置され、少なくとも前記光学式記録媒体に集光する前記第 1光ビ ームに発生する収差を補正する収差補正手段を更に有することを特徴とする請求項[3] The first optical beam disposed on the optical path and focused on at least the optical recording medium. The apparatus further comprises aberration correction means for correcting aberrations occurring in the beam.
1又は請求項 2に記載の光ピックアップ装置。 The optical pickup device according to claim 1 or 2.
[4] 前記往路集光手段は、前記第 1光路と前記第 2光路とを合成する合成手段と、前記 合成手段により合成された光路を介して前記光学式記録媒体に前記第 1、第 2及び 第 3光ビームを集光する集光手段と、を更に備えることを特徴とする請求項 1に記載 の光ピックアップ装置。 [4] The forward path condensing unit includes a combining unit that combines the first optical path and the second optical path, and the first and second optical recording media via the optical path combined by the combining unit. The optical pickup device according to claim 1, further comprising: a condensing unit that condenses the third light beam.
[5] 請求項 1乃至請求項 4の何れか一項に記載の光ピックアップ装置と、 [5] The optical pickup device according to any one of claims 1 to 4, and
前記光ピックアップ装置を駆動する駆動手段と、  Driving means for driving the optical pickup device;
前記駆動手段を制御することにより、前記光学式記録媒体に対する情報の記録及 び再生を制御する制御手段と、  Control means for controlling recording and reproduction of information on the optical recording medium by controlling the driving means;
前記光ピックアップ装置における受光結果に対応した信号を出力する出力手段と、 を具備することを特徴とする情報記録再生装置。  An information recording / reproducing apparatus comprising: output means for outputting a signal corresponding to a light reception result in the optical pickup device.
PCT/JP2006/303154 2005-03-30 2006-02-22 Optical pickup and information recorder/reproducer WO2006112135A1 (en)

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JP2005-099845 2005-03-30
JP2005099845A JP2008146685A (en) 2005-03-30 2005-03-30 Optical pickup device and information recording and reproducing device

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000276766A (en) * 1999-01-19 2000-10-06 Matsushita Electric Ind Co Ltd Optical pickup, optical information recording and reproducing device equipped therewith, and variable phase type wavelength plate used therefor
JP2004103189A (en) * 2002-09-13 2004-04-02 Hitachi Ltd Optical pickup device and optical disk device
JP2004319062A (en) * 2003-03-31 2004-11-11 Konica Minolta Holdings Inc Optical pickup device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000276766A (en) * 1999-01-19 2000-10-06 Matsushita Electric Ind Co Ltd Optical pickup, optical information recording and reproducing device equipped therewith, and variable phase type wavelength plate used therefor
JP2004103189A (en) * 2002-09-13 2004-04-02 Hitachi Ltd Optical pickup device and optical disk device
JP2004319062A (en) * 2003-03-31 2004-11-11 Konica Minolta Holdings Inc Optical pickup device

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