WO2005043522A1 - 光ピックアップ装置、及び光ピックアップ装置に用いる補正素子 - Google Patents
光ピックアップ装置、及び光ピックアップ装置に用いる補正素子 Download PDFInfo
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- WO2005043522A1 WO2005043522A1 PCT/JP2004/016366 JP2004016366W WO2005043522A1 WO 2005043522 A1 WO2005043522 A1 WO 2005043522A1 JP 2004016366 W JP2004016366 W JP 2004016366W WO 2005043522 A1 WO2005043522 A1 WO 2005043522A1
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- pickup device
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Classifications
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- 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
- G11B7/1372—Lenses
- G11B7/1378—Separate aberration correction lenses; Cylindrical lenses to generate astigmatism; Beam expanders
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- 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
- G11B7/1353—Diffractive elements, e.g. holograms or gratings
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- 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
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- 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
- G11B7/1372—Lenses
- G11B7/1374—Objective lenses
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- 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
- G11B7/139—Numerical aperture control means
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- 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
- G11B7/1392—Means for controlling the beam wavefront, e.g. for correction of aberration
- G11B7/13922—Means for controlling the beam wavefront, e.g. for correction of aberration passive
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- 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 a pickup device and a correction element used in an optical pickup device.
- the present invention relates to an optical pickup device and a correction element used for the optical pickup device.
- Standards for high-density optical discs include, for example, those in which the image-side numerical aperture (NA) of the objective lens is about 0.85 and the protective substrate thickness is about 0.1 mm, and those in which the NA and the protective substrate thickness are those of a conventional DVD ( It is known to be about 0.65 mm and about 0.6 mm, which is about the same as a digital versatile disc.
- a high-density optical disk having a NA of about 0.65 and a protective substrate thickness of about 0.6 mm is referred to as “HD—DVD (High Density DVD) j.
- the wavelength of the light beam used for HD—DVD / DVD / CD is about 400 nm / about 650 nm / about 780 nm, respectively, and the protective substrate thickness t 1 / t 2 / Z t 3 is about 0.6 mm / SO. 6 mm / 'about 1.2 mm, respectively.
- Japanese Patent Application Laid-Open No. 2001-60336 discloses a technique in which a diffraction structure is provided on an optical surface of an optical element constituting an optical pickup device.
- the invention disclosed in Japanese Patent Application Laid-Open No. 2001-60336 is an optical pickup device for HD_D, DZDV D compatible or HD_D VDZD VD / CD compatible, in which a diffraction optical element and an objective lens are combined. This is used to correct chromatic aberration of HD-DVD.
- An object of the present invention is to provide an optical pick-up device which has at least compatibility between a high-density optical disk such as an HD-DVD and a DVD, and at the same time secures a sufficient amount of light and corrects chromatic aberration, and an object of the present invention.
- An object of the present invention is to provide a correction element as an optical system used in the apparatus.
- the optical pickup device of the first invention is:
- a first light source emitting a light beam having a wavelength ⁇ ⁇ (380 nm ⁇ A 1 ⁇ 450 nm), a second light source emitting a light beam having a wavelength ⁇ 2 (600 nm ⁇ A 2 ⁇ 700 nm), A light collecting optical element having a diffractive structure through which both the light beam of the wavelength ⁇ 1 and the light beam of the wavelength ⁇ 2 pass;
- a first correction element having a diffraction structure through which at least the light beam of wavelength ⁇ 1 passes; a second correction element having a diffraction structure through which at least the light beam of wavelength ⁇ 2 passes; an optical path of the light beam of wavelength 1 and the wavelength a beam splitter that matches the optical path of the light beam of ⁇ 2,
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source,
- the light beam having the wavelength ⁇ is generated on the first optical information recording medium by the nl (nl is a natural number) order diffracted light of the light beam of the wavelength ⁇ ⁇ ⁇ ⁇ generated by receiving the diffractive action from the condensing optical element.
- the second light is formed by a first condensing spot and an n 2 (112 is a natural number represented by! 1 1 ⁇ 112) -order diffracted light of the light beam of the wavelength ⁇ 2 generated by receiving a diffraction action from the condensing optical element.
- the chromatic aberration of both the second condensing spots formed on the information recording medium is suppressed to a range necessary for reproducing and / or recording information, and the absolute value of the chromatic aberration of the condensing optical element itself is reduced.
- the light flux emitted from the first light source is suppressed to 0.15 im / nm or less,
- chromatic aberration means that when the wavelength of light changes by +1 nm, The amount of change in the minimum position of the wavefront aberration in the direction of the optical axis of the converging spot on the information recording medium, with the direction away from the converging optical element being positive.
- the chromatic aberration of the element itself refers to the case where the element itself is evaluated, and when the wavelength of light changes by +1 nm, the minimum position of the wavefront aberration in the optical axis direction of the focusing spot is considered. This means that the amount of fluctuation is expressed with the direction away from the light-collecting optical element as positive.
- the “numerical aperture on the image plane side” refers to a numerical aperture (beam diameter conversion NA) converted from a spot diameter of a light collecting spot formed on an information recording surface of an optical information recording medium.
- the chromatic aberration of the condensing optical element itself and the chromatic aberration of the first correction element itself with respect to the first light beam emitted from the first light source are substantially zero, so that the optical pickup device can be used.
- the chromatic aberration of the first condensing spot at the time can be suppressed within a range necessary for reproducing and / or recording information.
- the optical pickup device of the second invention is
- Wavelength I 1 (380 ⁇ ⁇ ⁇ 1 ⁇ 450 nm), a first light source that emits a luminous flux, and a ⁇ 2 (600 ⁇ ⁇ 2 ⁇ 700 nm)
- a second light source that emits light
- a light-collecting optical element having a diffraction structure through which the light beam of the wavelength ⁇ 1 and the light beam of the wavelength ⁇ 2 pass;
- a beam splitter that matches an optical path of the light beam of the wavelength ⁇ 1 with an optical path of the light beam of the wavelength ⁇ 2,
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source;
- the light beam of the wavelength 1 is formed on the first optical information recording medium by nl (nl is a natural number) order diffracted light of the light beam of the wavelength 1 generated by being subjected to a diffractive action from the condensing optical element.
- the first condensing spot and the n 2 (!!!? !!!!: !?) Natural light diffracted light of the light beam of the wavelength ⁇ 2 generated by being subjected to diffraction by the condensing optical element.
- the second focusing spots formed on the second optical information recording medium both have chromatic aberration suppressed within a range necessary for information reproduction and / or recording, and have a chromatic aberration of the focusing optical element itself.
- the absolute value of the light emitted from the second light source is suppressed to 0.25 m / nm or less.
- the second correction element L2 is not provided with a diffraction structure, and the second correction element L2 is used for the second correction for the second light flux. Even when the element itself has chromatic aberration, the chromatic aberration of the second focusing spot can be suppressed to a range necessary for reproducing and / or recording information. In this case, a high light amount can be ensured because no loss of light amount occurs when the second light beam passes through the diffraction ring zone.
- the second correction element is provided with a diffraction structure, and the absolute value of the chromatic aberration of the second correction element itself is 3.5 jum / nm or less with respect to the light beam emitted from the second light source. It may be made to be suppressed to. In this way, the chromatic aberration of the condensing optical element itself and the second correction element itself with respect to the second light beam is suppressed to almost zero, so that the wavelength during the reproduction of the DVD and the tracking at the time of Z or recording is reduced. Even if fluctuations occur Deterioration of the surface aberration can be prevented.
- the optical pickup device of the third invention is:
- a first light source that emits a light beam having a wavelength ⁇ 380 (380 nm ⁇ A 1 ⁇ 450 nm); a second light source that emits a light beam having a wavelength of I 2 (600 ⁇ ⁇ ⁇ 2 ⁇ 700 nm); A light collecting optical element having a diffraction structure through which both the light beam of the wavelength 1 and the light beam of the wavelength ⁇ 2 pass;
- a first correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 1 passes; and a second correction element through which at least the light beam of the wavelength A2 passes,
- a beam splitter that matches an optical path of the light beam of the wavelength ⁇ 1 with an optical path of the light beam of the wavelength ⁇ 2,
- the light beam having the wavelength 1 is formed on the first optical information recording medium by the nl (nl is a natural number) order diffracted light of the light beam of the wavelength 1 generated by receiving a diffractive action from the condensing optical element,
- the chromatic aberration is suppressed within a range necessary for reproducing and recording information, and
- the value of the color difference of the light-collecting optical element itself with respect to the light beam emitted from the first light source, and the value of the chromatic aberration of the light-collecting optical element itself with respect to the light beam emitted from the second light source Is characterized by the same sign.
- the chromatic aberration of the light-collecting optical element itself may be positive for the light beam emitted from the first light source and the light beam emitted from the second light source.
- the value of the chromatic aberration of the second correction element itself with respect to the light beam emitted from the second light source may be negative.
- the chromatic aberration of the light-collecting optical element itself may be negative for the light beam emitted from the first light source and the light beam emitted from the second light source.
- the value of the chromatic aberration of the second correction element itself with respect to the light beam emitted from the second light source may be positive.
- the second correction element may be provided with a diffraction structure.
- the optical pickup device of the fourth invention is:
- a first light source that emits a light beam of wavelength ⁇ ⁇ (380 nm ⁇ A 1 ⁇ 450 nm), and emits a light beam of wavelength: I 2 (600 nm ⁇ A 2 ⁇ 700 nm)
- a second light source a light-collecting optical element having a diffraction structure through which both the light beam of the wavelength ⁇ 1 and the light beam of the wavelength ⁇ 2 pass,
- a first correction element through which at least the light beam of the wavelength ⁇ 1 passes; a second correction element having a diffraction structure through which at least the light beam of the wavelength band 2 passes;
- a beam splitter that matches an optical path of the light beam of the wavelength ⁇ 1 with an optical path of the light beam of the wavelength beam 2;
- the reproduction and Z ′ or recording of information are performed on the first optical information recording medium having the protective substrate thickness t 1 (O mm ⁇ t 1 ⁇ 0.7 mm),
- reproduction and Z or recording of information are performed on a second optical information recording medium having a protective substrate thickness t2 (0.5 mm ⁇ t2 ⁇ 0.7 mm),
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source;-when the optical pickup device is used, A first condensing spot formed on the first optical information recording medium by ⁇ 1 (where ⁇ 1 is a natural number) diffracted light of the light beam having the wavelength ⁇ 1 generated by receiving a diffraction action from the optical optical element; It is formed on the second optical information recording medium by the ⁇ 2 (11 2 is a natural number represented by 11 1 211 2) order diffracted light of the light beam of the wavelength 2 generated by receiving the diffraction action from the condensing optical element.
- the chromatic aberration is suppressed within a range necessary for reproducing and / or recording information, and the light collecting optical element itself has a light beam emitted from the first light source.
- the color difference value and the light output from the second light source And chromatic aberration value that Yusuke said converging optical element itself with respect to light beam is characterized in that it is a different code.
- the value of the chromatic aberration of the second correction element itself with respect to the light beam emitted from the second light source may be negative.
- the first correction element may be provided with a diffraction structure.
- the light-collecting optical element may be made of plastic.
- the first correction element may be made of plastic.
- the second correction element may be made of plastic.
- the focal length f of the light-collecting optical element with respect to the light beam of the wavelength ⁇ 1 may satisfy 1 mm ⁇ f ⁇ 4 mm.
- the focal length f1 of the first correction element with respect to the light beam of the wavelength ⁇ 1 may satisfy 5.5 mm ⁇ f1 ⁇ 32 mm.
- the focal length f 2 of the second correction element with respect to the light beam of the wavelength 2 may be such that f 2 force S, 5.5 mm ⁇ f 2 ⁇ 32 mm.
- optical system magnification m 1 force from the first light source to the first optical information recording medium with respect to the light beam having the wavelength 1 may be set to satisfy 1 ⁇ 1 ⁇ ml ⁇ 1, and 10. ,.
- optical system magnification m 2 force from the second light source to the second optical information recording medium with respect to the light beam of the wavelength ⁇ 2 may be set to satisfy m 2 force-1 / 3 ⁇ m2 ⁇ -1, 10. ,.
- the numerical aperture ⁇ 1 on the image plane side of the light beam of the wavelength ⁇ 1 of the condensing optical element may satisfy 0.63 ⁇ 1 ⁇ 0.67. .
- the numerical aperture ⁇ 2 on the image plane side of the light-collecting optical element with respect to the light beam of the wavelength ⁇ 2 when the optical pickup device is used may satisfy 0.59 ⁇ ⁇ 2 ⁇ 0.67.
- At least one of the first correction element and the second correction element may be a collimating lens.
- a third light source that emits a light beam of wavelength 3 (750 nm ⁇ A 3 ⁇ 800 nm) is provided.
- the protective substrate thickness t 3 (1) is obtained by using the n 3 (n 3 is a natural number) order diffracted light of the light beam of the wavelength ⁇ 3 generated by receiving a diffraction effect from the light collecting optical element. lmm ⁇ t3 ⁇ 1.3 mm), information may be reproduced and / or recorded on the third optical information recording medium.
- an optical system magnification m3 force from the third light source to the third optical information recording medium with respect to the light having the wavelength ⁇ 3 is set so as to satisfy force _ 1 z'4 ⁇ m3 ⁇ 1. 1.10.
- n1, n2, and n3 (0, 1, 0), (2, 1, 1), (3, 2, 2), (5, 3, 3) or (8, 5, 4).
- the light beam having the wavelength 3 may pass through the second correction element.
- the second light source and the third light source may be packaged light sources.
- the diffraction structure may be provided on both the incident surface and the emission surface of the second correction element.
- the correction element used for the optical pickup device of the fifth invention is as follows.
- the first correction element used in the pick-up device is the first correction element used in the pick-up device
- the pickup device The pickup device,
- a first light source that emits a light beam having a wavelength ⁇ ⁇ (380 nm ⁇ A 1 ⁇ 450 nm); a second light source that emits a light beam having a wavelength of I 2 (600 nm ⁇ A 2 ⁇ 700 nm); A light collecting optical element having a diffraction structure through which both the light beam of the wavelength 1 and the light beam of the wavelength ⁇ 2 pass;
- a first correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 1 passes; a second correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 2 passes; and an optical path of the light beam of the wavelength ⁇ .
- a beam splitter that matches an optical path of the light beam of the wavelength ⁇ 2,
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source;
- the light beam having the wavelength ⁇ is generated on the first optical information recording medium by an nl (nl is a natural number) order diffracted light of the light beam of the wavelength ⁇ ⁇ ⁇ ⁇ generated by receiving a diffractive action from the condensing optical element.
- the second condensing spot and the n 2 (12 is a natural number of 11 1 ⁇ 112) order diffracted light of the light beam of the wavelength ⁇ 2 generated by receiving a diffraction action from the condensing optical element are used to produce the second light.
- the chromatic aberration is suppressed within a range necessary for information reproduction and Z or recording.
- the absolute value of the chromatic aberration of the condensing optical element itself is suppressed to 0.15 jum. ⁇ ⁇ ⁇ ⁇ ⁇ or less with respect to the light beam emitted from the first light source. On the other hand, it is less than 0.25 0m
- the absolute value of chromatic aberration of the first correction element itself is suppressed to 2.1 jWmZnm or less with respect to a light beam emitted from the first light source.
- the correction element used in the optical pickup device of the sixth invention is:
- the pickup device The pickup device,
- a first light source that emits a light beam of wavelength ⁇ 1 (380 ⁇ ⁇ 1 ⁇ 450 nm) and a second light source that emits a light beam of wavelength ⁇ 2 (600 nm ⁇ A 2 ⁇ 700 nm) (2) a light source, a light-collecting optical element having a diffraction structure through which the light beam of the wavelength ⁇ 1 and the light beam of the wavelength ⁇ 2 pass,
- a first correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 1 passes; a second correction element through which at least the light beam of the wavelength band 2 passes;
- a beam splitter that matches an optical path of the light beam of the wavelength 1 with an optical path of the light beam of the wavelength ⁇ 2,
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source;
- the light beam having the wavelength ⁇ is generated on the first optical information recording medium by an nl (nl is a natural number) order diffracted light of the light beam of the wavelength ⁇ ⁇ ⁇ ⁇ generated by receiving a diffractive action from the condensing optical element.
- the second condensing spot and the n 2 (11 2 is a natural number of 11 1 ⁇ 112) order diffracted light of the light beam of the wavelength ⁇ 2 generated by being subjected to the diffraction action from the condensing optical element.
- the chromatic aberration is suppressed to a range necessary for reproducing and / or recording information
- the absolute value of the chromatic aberration of the condensing optical element itself is:
- the light flux emitted from the first light source is suppressed to 0.15 m / nm or less
- the light flux emitted from the second light source is suppressed to 0.25 ji mZnni or less. It is characterized by.
- the second correction element is provided with a diffraction structure, and the absolute value of the chromatic aberration of the second correction element itself is 3.5 jwm / nm or less with respect to the light beam emitted from the second light source. Even if it is controlled to be.
- the correction element used in the optical pickup device of the present invention is:
- the first correction element used in the pickup device is the first correction element used in the pickup device.
- the pickup device The pickup device,
- a first light source emitting a light beam of wavelength ⁇ 1 (380 nm ⁇ A l ⁇ 450 nm); a second light source emitting a light beam of wavelength; I 2 (600 nm ⁇ A 2 ⁇ 700 nm); a light collecting optical element having a diffractive structure through which both the light beam of ⁇ 1 and the light beam of the wavelength ⁇ 2 pass;
- a first correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 1 passes; a second correction element through which at least the light beam of the wavelength ⁇ 2 passes; an optical path of the light beam of the wavelength ⁇ .1 and the wavelength ⁇ Beam that matches the optical path of the luminous flux of 2 Having a splitter and
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source,
- the light beam having the wavelength ⁇ is generated on the first optical information recording medium by the nl (nl is a natural number) order diffracted light of the light beam of the wavelength ⁇ ⁇ ⁇ ⁇ generated by being subjected to the diffraction action from the light collecting optical element.
- the first condensing spot and the n2 (112 is a natural number represented by 11 1 ⁇ 11 2) order diffracted light of the light beam of the wavelength 2 generated by being subjected to the diffraction action from the condensing optical element are used to produce the second condensed light.
- the second focusing spots formed on the optical information recording medium both have chromatic aberration suppressed within a range necessary for reproducing and / or recording information, and-a light flux emitted from the first light source. That is, the value of the color difference of the condensing optical element itself and the value of the chromatic aberration of the condensing optical element itself with respect to the light beam emitted from the second light source have the same sign.
- the chromatic aberration of the light-collecting optical element itself may be positive for the light beam emitted from the first light source and the light beam emitted from the second light source.
- the value of the chromatic aberration of the second correction element itself with respect to the light beam emitted from the second light source may be negative.
- the chromatic aberration of the light-collecting optical element itself may be negative for the light beam emitted from the first light source and the light beam emitted from the second light source.
- the second correction element body has a light beam emitted from the second light source. Even if the value of chromatic aberration is positive.
- the second correction element may be provided with a diffraction structure.
- the correction element used for the optical pickup device of the eighth invention is:
- the first correction element used in the pickup device is the first correction element used in the pickup device
- the pickup device The pickup device,
- a first correction element through which at least the light beam of the wavelength ⁇ 1 passes;
- a second correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 2 passes, and a beam splitter that matches an optical path of the light beam of the wavelength ⁇ 1 with an optical path of the light beam of the wavelength ⁇ 2,
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source,
- the light beam of the wavelength 1 is formed on the first optical information recording medium by nl (nl is a natural number) order diffracted light of the light beam of the wavelength 1 generated by being subjected to a diffractive action from the condensing optical element.
- the first condensing spot and the light from the condensing The wavelength lambda 2 of the light beams n 2 that occurs by receiving the folding action (112 111 ⁇ 1 12 Dea Ru natural number) second condensing spot formed on the second optical information recording medium by order diffracted light
- the chromatic aberration is suppressed within a range necessary for reproducing and / or recording information, and the value of the chromatic aberration of the light-collecting optical element itself with respect to the light beam emitted from the first light source
- the luminous flux emitted from the two light sources has a different sign from the value of the chromatic aberration of the condensing optical element itself.
- the value of the chromatic aberration of the second correction element itself with respect to the light beam emitted from the second light source may be negative.
- the first correction element may be provided with a diffraction structure.
- the light-collecting optical element may be made of plastic.
- the first correction element may be made of plastic.
- the second correction element may be made of plastic.
- the focal length f of the light-collecting optical element with respect to the light beam of the wavelength ⁇ 1 may satisfy 1 mm ⁇ f ⁇ 4 mm.
- the focal length f 1 of the light beam having the wavelength ⁇ 1 may satisfy the condition of 5.5 mm ⁇ f 1 ⁇ 32 mm.
- the focal length f 2 of the second correction element for the light beam of the wavelength ⁇ 2 may satisfy 5.5 mm ⁇ f 2 ⁇ 32 mm.
- optical system magnification m 1 force S from the first light source to the first optical information recording medium with respect to the light beam of the wavelength ⁇ , _l / 3 ⁇ ml ⁇ ⁇ 110 may be satisfied.
- an optical system magnification m2 force S from the second light source to the second optical information recording medium with respect to the light beam of the wavelength ⁇ 2, 1 l / 3 ⁇ m2 ⁇ -1Z10 may be satisfied.
- N A1 force 0.63 ⁇ NA1 ⁇ 0.67 on the image plane side with respect to the light beam of the wavelength ⁇ 1 of the condensing optical element when the optical pickup device is used.
- the numerical aperture ⁇ 2 on the image plane side of the light beam of the wavelength ⁇ 2 of the condensing optical element may satisfy 0.59 ⁇ 2 ⁇ 0.67. .
- At least one of the first correction element and the second correction element may be a collimating lens.
- the optical pickup device includes a third light source that emits a light beam having a wavelength of ⁇ 3 (750 nm ⁇ A 3 ⁇ S 00 nm), and when using the optical pickup device, diffracts the light from the condensing optical element. Is formed on the third optical information recording medium having a protective substrate thickness t 3 (1.lmm ⁇ t 3 ⁇ 1.3 mm) by the n 3 (n 3 is a natural number) order diffracted light of the light beam of the wavelength 3 generated by the light receiving.
- the third condensed spot may have chromatic aberration suppressed to a range necessary for reproducing and / or recording information.
- an optical system magnification m3 force S from the third light source to the third optical information recording medium with respect to the light beam of the wavelength ⁇ 3, and 1 l / 4 ⁇ m3 ⁇ -1 / 10 may be satisfied.
- the light beam of the wavelength ⁇ 3 may pass through the second correction element.
- the second light source and the third light source may be a packaged light source unit.
- the diffraction structure may be provided on both the entrance surface and the emission surface of the second correction element.
- the correction element used in the optical pickup device of the ninth invention is:
- the second correction element used in the pickup device is the second correction element used in the pickup device
- the pickup device The pickup device,
- a first light source that emits a light beam of wavelength ⁇ 1 (380 nm ⁇ A 1 ⁇ 450 nm), a second light source that emits a light beam of wavelength ⁇ 2 (600 nm ⁇ A 2 ⁇ 700 nm), and the wavelength ⁇ 1
- a light collecting optical element having a diffractive structure through which the light beam of the wavelength ⁇ 2 and the light beam of the wavelength ⁇ 2 pass;
- a first correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 1 passes; a second correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 2 passes; an optical path of the light beam of the wavelength ⁇ 1;
- a beam splitter that matches an optical path of a light beam with a wavelength ⁇ 2, Reproducing and / or recording information on a first optical information recording medium having a protective substrate thickness t 1 (0 mm ⁇ t 1 ⁇ 0.7 mm) using the light beam of the wavelength ⁇ 1,
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source;
- the light beam having the wavelength ⁇ is generated on the first optical information recording medium by an nl (nl is a natural number) order diffracted light of the light beam of the wavelength ⁇ ⁇ ⁇ ⁇ generated by receiving a diffractive action from the condensing optical element.
- the chromatic aberration is suppressed to a range necessary for reproducing and / or recording information
- the absolute value of the chromatic aberration of the condensing optical element itself is:
- the light flux emitted from the first light source is suppressed to 0.15 mZnm or less
- the light flux emitted from the second light source is suppressed to 0.25 jUm.Z nm or less.
- the absolute value of the chromatic aberration of the first correction element itself is calculated from the first light source. Wherein the 2 is suppressed to less than 1 ni / nm with respect to light flux Isa.
- the correction element used in the optical pickup device of the tenth invention is
- the second correction element used in the pick-up device is the second correction element used in the pick-up device
- the pickup device The pickup device,
- a first light source emitting a light beam of wavelength ⁇ 1 (380 nm ⁇ A 1 ⁇ 450 nm); a second light source emitting a light beam of wavelength; I 2 (600 nm ⁇ A 2 ⁇ 700 nm); A light collecting optical element having a diffractive structure through which both the light beam of the wavelength ⁇ 1 and the light beam of the wavelength ⁇ 2 pass;
- a first correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 1 passes, and a second correction element through which at least the light beam of the wavelength ⁇ 2 passes,
- a beam splitter that matches an optical path of the light beam of the wavelength ⁇ 1 with an optical path of the light beam of the wavelength beam 2;
- reproduction and Z or recording of information are performed on a first optical information recording medium having a protective substrate thickness t1 (Omm ⁇ t1 ⁇ 0.7 mm),
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source;
- the light beam of the wavelength 1 is formed on the first optical information recording medium by nl (nl is a natural number) order diffracted light of the light beam of the wavelength 1 generated by being subjected to a diffractive action from the condensing optical element.
- the second light information is obtained by an n 2 (112 is a natural number of 11 1 ⁇ 112) -order diffracted light of the light beam of the wavelength 2 generated by the first condensing spot and the diffraction action from the condensing optical element.
- the chromatic aberration of both the second condensing spots formed on the recording medium is suppressed to a range necessary for reproducing and / or recording information, and the absolute value of the chromatic aberration of the condensing optical element itself is:
- the light flux emitted from the first light source is suppressed to 0.15 jWmZnni or less, and the light flux emitted from the second light source is suppressed to 0.25 jt / mZnm or less.
- the second correction element is provided with a diffraction structure, and the absolute value of the chromatic aberration of the second correction element itself is 3.5 ⁇ with respect to the light beam emitted from the second light source. You may make it hold it below Znm.
- the correction element used for the optical pickup device of the eleventh invention is
- the second correction element used in the pickup device is the second correction element used in the pickup device
- the pickup device The pickup device,
- a first light source that emits a light beam having a wavelength ⁇ 380 (380 nm ⁇ A l ⁇ 450 nm); a second light source that emits a light beam having a wavelength of I 2 (600 nm ⁇ A 2 ⁇ 700 nm); A light collecting optical element having a diffraction structure through which both the light beam of the wavelength 1 and the light beam of the wavelength ⁇ 2 pass;
- a first correction element having a diffraction structure through which at least the light beam of the wavelength 1 passes; a second correction element through which a light beam of at least the wavelength; 12 passes;
- a beam splitter that matches an optical path of the light beam of the wavelength ⁇ 1 with an optical path of the light beam of the wavelength ⁇ 2,
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source;
- the optical pickup device When the optical pickup device is used, it is formed on the first optical information recording medium by the nl (nl is a natural number) order diffracted light of the light beam of the wavelength ⁇ ⁇ ⁇ ⁇ generated by receiving a diffraction action from the light-collecting optical element.
- the second condensing spot formed on the second optical information recording medium by the (natural number) th order diffracted light has a chromatic aberration within a range necessary for reproducing and / or recording information.
- the chromatic aberration of the light-collecting optical element itself may be positive for the light beam emitted from the first light source and the light beam emitted from the second light source.
- the value of the chromatic aberration of the second correction element itself with respect to the light beam emitted from the second light source may be negative.
- the chromatic aberration of the light-collecting optical element itself may be negative for the light beam emitted from the first light source and the light beam emitted from the second light source.
- the value of the chromatic aberration of the second correction element itself with respect to the light beam emitted from the second light source may be positive.
- the second correction element may be provided with a diffraction structure.
- the correction element used in the optical pickup device of the first invention is
- the pickup device The pickup device,
- a first light source that emits a light beam of wavelength ⁇ 1 (380 nm ⁇ A l ⁇ 450 nm) and a second light source that emits a light beam of wavelength ⁇ 2 (600 nm ⁇ A 2 ⁇ 700 nm) (2) a light source, a light collecting optical element having a diffractive structure through which the light beam of the wavelength ⁇ 1 and the light beam of the wavelength ⁇ 2 pass, and a first correction element through which at least the light beam of the wavelength ⁇ 1 passes.
- a second correction element having a diffraction structure through which at least the light beam of the wavelength ⁇ 2 passes, and a beam splitter that matches an optical path of the light beam of the wavelength ⁇ 1 with an optical path of the light beam of the wavelength ⁇ 2,
- At least one of the first correction element and the second correction element is disposed between the beam splitter and the first light source or the second light source,
- the light beam having the wavelength ⁇ is generated on the first optical information recording medium by the nl (nl is a natural number) order diffracted light of the light beam of the wavelength ⁇ ⁇ ⁇ ⁇ generated by being subjected to the diffraction action from the light collecting optical element.
- the first condensing spot and the n2 (112 is a natural number of 11 1 ⁇ 12) order diffracted light of the light beam of the wavelength ⁇ 2 generated by being subjected to a diffraction action from the condensing optical element are used to produce the second condensed light.
- the chromatic aberration is suppressed within a range necessary for reproducing and recording information or recording, and the light flux emitted from the first light source is reduced.
- the value of the color difference of the light collecting optical element itself and the value of the chromatic aberration of the light collecting optical element itself with respect to the light beam emitted from the second light source are different signs.
- the value of the chromatic aberration of the second correction element itself with respect to the light beam emitted from the second light source may be negative.
- the first correction element may be provided with a diffraction structure.
- the light-collecting optical element is made of plastic. Is also good.
- the first correction element may be made of plastic.
- the second correction element may be made of plastic.
- the focal length f of the light-collecting optical element with respect to the light beam of the wavelength ⁇ 1 may satisfy 1 mm ⁇ f ⁇ 4 mm.
- the focal length f1 of the first correction element with respect to the light beam of the wavelength 1 may be set to satisfy 5.5 mm ⁇ f1 ⁇ 32 mm.
- the focal length f2 of the second correction element with respect to the light beam of the wavelength 2 may be 5.5 mm ⁇ f2 ⁇ 32 mm.
- an optical system magnification m 1 from the first light source to the first optical information recording medium with respect to the light flux of the wavelength ⁇ is set so as to satisfy the following equation: Well.
- the optical system magnification m 2 from the second light source to the second optical information recording medium with respect to the light beam of the wavelength ⁇ 2 may be set to satisfy m 2 car 1′3 ⁇ 1112 ⁇ ⁇ 1 / 10. No. ,
- a numerical aperture NA 1 on the image plane side of the light-collecting optical element with respect to the light beam having the wavelength 1 may satisfy 0.61 ⁇ NA 1 ⁇ 0.67. .
- the numerical aperture NA2 on the image surface side of the light-collecting optical element with respect to the light beam of the wavelength 2 may satisfy 0.59 ⁇ NA2 ⁇ 0.67. Ray.
- At least one of the first correction element and the second correction element may be a collimating lens.
- the optical pickup device includes a third light source that emits a light beam having a wavelength of ⁇ 3 (750 nm ⁇ A 3 ⁇ 800 nm), and when the optical pickup device is used, a diffractive action from the condensing optical element is performed.
- a diffractive action from the condensing optical element is performed.
- the luminous flux of wavelength ⁇ 3 generated by receiving light on the third optical information recording medium having a protective substrate thickness t 3 (1.l mm ⁇ t 3 ⁇ 1.3 mm) due to the n 3 (n 3 is a natural number) order diffracted light.
- the chromatic aberration of the third condensed spot formed on the surface may be suppressed to a range necessary for reproducing and / or recording information.
- an optical system magnification m3 from the third light source to the third optical information recording medium with respect to the light beam of the wavelength ⁇ 3 is set so as to satisfy ⁇ 1/4 ⁇ m3 ⁇ ⁇ 1.10.
- n1, n2, and n3 (0, 1, 0), (2, 1, 1), (3, 2, .2), (5, 3, 3), (8, 5, 4).
- the light beam of the wavelength ⁇ 3 may pass through the second correction element.
- the second light source and the third light source may be a packaged light source unit.
- the diffraction structure may be provided on both the entrance surface and the emission surface of the second correction element.
- an optical pickup device which has at least compatibility between HD-DVD and DVD, and at the same time secures light quantity and corrects chromatic aberration, and a correction element (first correction) as an optical system used in the optical pickup device Element, second correction element).
- FIG. 1 is a main part plan view showing the configuration of an optical pickup device according to the present invention.
- FIG. 2 is a plan view of a principal part showing the structure of the light-collecting optical element.
- FIG. 3 (a) to FIG. 3 (e) are diagrams showing chromatic aberration of the condensing optical element.
- FIG. 4 is a plan view of a principal part showing the structure of the light-collecting optical element.
- FIG. 5 is a main part plan view showing the configuration of the optical pickup device according to the present invention.
- FIG. 1 shows the proper recording / reproduction of information for both HD—DVD (first optical information recording medium), DVD (second optical information recording medium) and CD (third optical information recording medium).
- FIG. 4 is a diagram schematically showing a configuration of a first optical pickup device PU1 that can perform the above.
- the thickness t3 of Example 3 is 1.2 mm and the number of openings NA3 is 0.51.
- the combination of wavelength, protective layer thickness, and numerical aperture is This is limited to this.
- the optical pickup device PU1 is a blue-violet semiconductor laser LD1 (first light source) that emits a 407 nm laser light beam (first light beam) and emits a light beam when recording and reproducing information on an HD DVD.
- Light detector PD 1 for light beam red semiconductor laser LD 2 (second light source) that emits 655 nm laser light beam (second light beam) and emits light when recording / reproducing information to / from DVD and CD
- a light source unit LU23 which is integrated with an infrared semiconductor laser LD3 (third light source) that emits a 785 nm laser light beam (third light beam) and emits light when recording and reproducing
- the first correction element L1, the second correction element L2, and the objective lens @BJ are provided with diffraction structures.
- the blue-violet semiconductor laser LD1 When recording and reproducing information on an HD-DVD in the optical pickup device PU1, the blue-violet semiconductor laser LD1 is first made to emit light, as shown by the light path in solid lines in FIG.
- the divergent light beam emitted from the blue-violet semiconductor laser LD 1 passes through the first beam splitter BS 1, is converted into a parallel light beam by passing through the first correction element L 1, and then is converted into the second beam splitter. After passing through BS 2, it reaches the focusing optical element OB J. .
- nl nl is a natural number
- the chromatic aberration is suppressed within a range necessary for reproducing and / or recording information.
- the absolute value of the chromatic aberration of the first focused spot is set to 0.15 m Znm or less. I am holding it down. ⁇ ⁇
- the focusing optical element OB J performs focusing / tracking by a two-axis actuator AC (not shown) arranged around the focusing optical element OB J.
- the reflected light flux modulated by the information pits on the information recording surface RL 1 passes through the condensing optical element OB J, the second beam splitter BS 2 and the first correction element L 1 again, and passes through the first beam splitter BS 1. It is branched and given astigmatism by the sensor lens S EN 1 and the photodetector P
- the red semiconductor laser LD2 When information is recorded / reproduced on / from a DVD, the red semiconductor laser LD2 is first made to emit light as indicated by the dashed line in FIG. The divergent light beam emitted from the red semiconductor laser LD 2 is applied to a third beam source. After passing through the liter B S3 and passing through the second correction element L2, it is converted into a parallel light flux, and then reflected by the second beam splitter B S2 to reach the condensing optical element OBJ.
- the n 2 (n 2 is a natural number that is n 1 ⁇ n 2) order diffracted light of the second light beam generated by receiving a diffractive action from the diffractive structure of the condensing optical element OBJ passes through the DVD protective layer PL 2.
- a spot (second light spot) is formed by condensing light on the information recording surface RL2.
- the chromatic aberration is suppressed within a range necessary for reproducing and / or recording information.
- the absolute value of the chromatic aberration of the second focused spot is 0.25 jUm / nm. It is kept below.
- the condensing optical element #BJ performs focusing / tracking by a two-axis actuator AC arranged around the condensing optical element #BJ.
- the reflected light flux modulated by the information pits on the information recording surface RL2 passes through the condensing optical element ⁇ BJ, the second beam splitter BS2, and the second correction element L2 again, and passes through the third beam splitter BS3. And converges on the light receiving surface of the photodetector PD23.
- the information recorded on the DVD can be read using the output signal of the photodetector PD23.
- the infrared semiconductor laser LD3 When recording and / or reproducing information from / to a CD, first, the infrared semiconductor laser LD3 is made to emit light, as indicated by the dotted line in FIG.
- the divergent light beam emitted from the infrared semiconductor laser LD3 passes through the third beam splitter BS3, is emitted from the second correction element L2 as divergent light, and is emitted from the second beam splitter BS2.
- the light is reflected and reaches the condensing optical element OBJ.
- the n 3 ( ⁇ 3 is a natural number) order diffracted light of the third light flux generated by receiving a diffractive action from the diffraction structure of the condensing optical element ⁇ BJ is transmitted to the information recording surface RL via the protective layer PL 3 of the CD.
- a spot (third focusing spot) is formed by focusing the light on 3. The chromatic aberration of the third condensing spot is suppressed within a range necessary for reproducing and / or recording information.
- the focusing optical element OB J performs focusing / tracking by a two-axis actuator AC arranged around the focusing optical element OB J.
- the reflected light flux modulated by the information pits on the information recording surface RL3 passes through the condensing optical element OBJ, the second beam splitter BS2, and the second correction element L2 again, and passes through the third beam splitter.
- the light is branched at BS 3 and converges on the light receiving surface of the photodetector PD23.
- the information recorded on the CD can be read using the output signal of the photodetector PD23.
- the condensing optical element OBJ transmits the first to third light beams to the information recording surface RL 1 to RL of the optical disc.
- This is a single-sided plastic lens with a double-sided aspheric surface that has the function of condensing light on top of it.
- a condensing optical element may be configured by combining a plurality of optical elements.
- a blazed diffraction structure DOE as shown in FIG. 2 is formed on the incident surface of the light-collecting optical element OBJ.
- the blazed diffraction structure DOE is provided to correct the chromatic aberration of the light collecting optical element OBJ itself with respect to the light beam emitted from the first light source.
- the absolute value of the chromatic aberration is 0. It is designed to be less than 15 / mZnm.
- the first correction element L1 has a collimating function of emitting the first light flux emitted as divergent light from the first light source LD1 as parallel light, and has the same exit surface as that shown in FIG.
- a blazed diffraction structure DOE is formed. This blazed diffraction structure DOE is provided to correct the chromatic aberration of the first correction element L1 itself with respect to the light beam emitted from the first light source. Specifically, the absolute value of the chromatic aberration is 2. Designed to be less than 1 U m / 'nm.
- the second correction element L2 has a collimating function of emitting the second light flux emitted from the second light source LD2 as divergent light as parallel light, and the third light emitted as divergent light from the third light source LD3. It has the function of changing the divergence angle of the light beam to a smaller divergence angle and emitting the light, and a blazed diffraction structure D ⁇ E similar to that shown in Fig. 2 is formed on its entrance and exit surfaces. ing.
- FIG. 3 (a) is a diagram showing the value of the chromatic aberration of the condensing optical element itself for the first light beam and the second light beam, and the value of the chromatic aberration of the condensing optical element itself for the first light beam. Is indicated by a circle, and the value of the chromatic aberration of the condensing optical element itself with respect to the second light flux is indicated by a square. From Fig. 3 (a), the value of the chromatic aberration of the condensing optical element itself with respect to the first light beam is, as described above, due to the blazed diffraction structure DOE formed in the condensing optical element. It can be seen that the absolute value is less than 0. ⁇ ⁇ ⁇ ⁇ ⁇ , that is, almost zero.
- the chromatic aberration of the first correction element itself with respect to the first light beam has an absolute value of 2 due to the blazed diffraction structure DOE formed in the first correction element. . It is less than l ⁇ m / nm, that is, almost zero.
- the chromatic aberration of the condensing optical element itself and the chromatic aberration of the first correcting element itself for the first light flux substantially zero, the chromatic aberration of the first condensed spot at the time of using the optical pickup device can be reproduced and reproduced. Alternatively, it can be kept within the range necessary for recording.
- the booze-type diffraction structure DOE of the condensing optical element is designed so that the chromatic aberration of the condensing optical element itself with respect to the first light beam is almost zero, as shown in FIG. 3 (a),
- the chromatic aberration of the condensing optical element itself remains, and specifically, the value of the chromatic aberration becomes negative.
- the blaze between the entrance surface and the exit surface of the second correction element is adjusted so that the value of the chromatic aberration of the second correction element itself with respect to the second light flux is positive.
- -Type diffraction structure D ⁇ E is designed.
- the chromatic aberration of the second condensed spot when using the optical pickup device can be obtained. It can be kept within the range necessary for reproduction and / or recording.
- Design techniques for appropriately changing the value of the chromatic aberration of the optical element itself with respect to a specific light beam using a diffractive structure formed on the optical element are well known, and thus description thereof will be omitted.
- a folding structure for example, as shown in FIG. 4, a plurality of orbicular zones R with a stepped structure formed therein, and a superimposed diffraction structure HOE, which is a structure arranged around the optical axis, may be used. Good.
- nl is the wavelength of the aberration correction element L 1;
- a laser beam of wavelength ⁇ 1 When a laser beam of wavelength ⁇ 1 is incident on this superimposed diffraction structure HOE, an optical path difference of k ⁇ 1 (fl rn) is generated between adjacent steps, and the laser beam of wavelength ⁇ 1 is substantially Since there is no phase difference, the light passes through without being diffracted.
- a light beam which is transmitted without any substantial phase difference by the superimposed diffraction structure is referred to as a zero-order diffracted light.
- the diffraction efficiency of the first-order diffracted light of the laser beam of 3 ⁇ 4 length ⁇ 2 is 87.5%
- the light intensity is sufficient for recording and reproducing information on DVDs and DVDs.
- the spherical aberration caused by the difference in the thickness of the protective layer between the HD DVD and the DVD is corrected by the function of the superimposed diffraction structure HOE. can do.
- 3 2 X ⁇ 1
- an optical path difference of 1 X ⁇ 3 (jm) occurs between adjacent steps, and the laser beam of wavelength 3 is substantially the same as the laser beam of wavelength 1 Since it has no phase difference, it is transmitted without diffraction (zero-order diffracted light).
- the converging optical element OB J uses different magnifications for the wavelength ⁇ 1 and the wavelength;
- the spherical aberration caused by the difference in the thickness of the protective layer can be corrected.
- the wavelength selectivity of the superimposed diffraction structure HOE is used as described above.
- the first correction element L1 is disposed between the second beam splitter BS2 and the condensing optical element ⁇ BJ, the first to third light beams pass through the first correction element L1. Therefore, in this case, a superimposition type diffraction structure HOE is formed in the first correction element L1, and the first correction element uses the wavelength selectivity of the superposition type diffraction structure HOE to convert the light into the first light beam.
- a configuration can be adopted in which a diffraction effect is given only to the second light beam and the second light beam and the third light beam are not given a diffraction effect.
- the condensing optical element itself for the first light flux and the first correction element are used.
- the chromatic aberration of the positive element itself By suppressing the chromatic aberration of the positive element itself to almost zero, it is possible to prevent the wavefront aberration from being deteriorated even if the wavelength varies during the tracking of the reproduction and / or recording of the HD DVD.
- the light source unit LU23 in which the second light source LD2 and the third light source LD3 are integrated the second light flux and the third light flux are made to enter the second correction element, thereby achieving the second correction.
- the diffractive structures provided on the entrance and exit surfaces of the element L2 it is possible to obtain a sufficient amount of light and a function of suppressing aberration in DVDs and CDs.
- the first correction element L1, the second correction element L2, and the objective lens OBJ are provided with a diffraction structure.
- FIG. 3 (b) is a diagram showing the value of the chromatic aberration of the condensing optical element itself for the first light beam and the second light beam, and the value of the chromatic aberration of the condensing optical element itself for the first light beam. Is indicated by a circle, and the value of the chromatic aberration of the condensing optical element itself with respect to the second light flux is indicated by a square.
- the absolute value of the chromatic aberration of the condensing optical element itself with respect to the second light flux is 0.25 mZnm or less due to the blazed diffraction structure DOE formed in the condensing optical element OBJ. That is, it turns out that it becomes almost zero.
- the absolute value of the chromatic aberration of the second correction element itself with respect to the second light beam is also obtained by the blazed diffraction structure DOE formed in the second correction element L2. It is less than 3.5 jU m. / 'Nm, that is, almost zero.
- the chromatic aberration of the condensing optical element itself and the chromatic aberration of the second correcting element itself substantially equal to the second light flux, the chromatic aberration of the second condensed spot when using the optical pickup device can be reproduced. And / or within the range required for recording.
- the blazed diffraction structure DOE of the condensing optical element ⁇ BJ is designed so that the chromatic aberration of the condensing optical element itself with respect to the second light flux is substantially zero, as shown in FIG. 3 (b),
- the chromatic aberration of the condensing optical element itself remains, and specifically, the value of the chromatic aberration becomes positive.
- the blazed diffraction structure DOE of the first correction element L1 is set so that the value of the chromatic aberration of the first correction element itself becomes negative with respect to the first light flux. Is designed.
- the chromatic aberration of the first condensing spot when using the optical pickup device can be obtained as information. Can be kept within the range necessary for reproduction and / or recording.
- the condensing optical element itself for the second light beam and the second correction element By suppressing the chromatic aberration itself to almost zero, it is possible to prevent the wavefront aberration from deteriorating even if the wavelength fluctuates at the time of DVD reproduction and tracking during Z or recording. .
- DVDs have lower requirements for chromatic aberration correction than HD-DVDs
- the second correction element L2 has no diffractive structure and the second correction element itself has a chromatic aberration with respect to the second light beam
- the chromatic aberration of the second focused spot can be reproduced and / or recorded.
- a large amount of light can be secured because no loss of light amount occurs when the second light beam passes through the diffraction zone.
- the first correction element L1, the second correction element L2, and the objective lens ⁇ BJ are provided with a diffraction structure.
- FIG. 3 (c) is a diagram showing the value of the chromatic aberration of the condensing optical element itself with respect to the first light beam and the second light beam. The value is indicated by a circle, and the value of the chromatic aberration of the condensing optical element itself with respect to the second light flux is indicated by a square. As can be seen from FIG. 3 (c), the value of the chromatic aberration of the condensing optical element itself with respect to the first light beam is positive.
- the blazed diffraction structure DOE of the first correction element L1 is set so that the value of the chromatic aberration of the first correction element itself becomes negative with respect to the first light flux. Is designed.
- the blazed diffraction structure DOE of the second correction element L2 is set so that the value of the chromatic aberration of the second correction element itself becomes negative with respect to the second light flux. Is designed.
- the chromatic aberration of the second condensed spot when using the optical pickup device can be obtained. It can be kept within the range necessary for reproduction and / or recording.
- the condensing optical elements for the first light beam and the second light beam Since the values of the chromatic aberrations of the light-emitting elements themselves have the same sign (positive), the diffractive effect of the blazed diffraction structure DOE formed on the condensing optical element OBJ can be reduced. Therefore, it is possible to improve workability and reduce the amount of light loss by increasing the diffraction pitch.
- the second light flux and the third light flux are made incident on the second correction element.
- the diffraction structure provided in the second capturing element L2 it is possible to obtain a sufficient amount of light and a function of suppressing a difference in a DVD and a CD.
- the arrangement of each element constituting the present embodiment is the same as that of the first embodiment, so that the illustration is omitted and the same.
- the same reference numerals are given to the configurations of and the description is omitted.
- the first correction element L1, the second correction element L2, and the objective lens OBJ are provided with diffraction structures.
- FIG. 3 (d) is a diagram showing the value of the chromatic aberration of the condensing optical element itself for the first light beam and the second light beam, and the value of the chromatic aberration of the condensing optical element itself for the first light beam. Is indicated by a circle, and the value of the chromatic aberration of the condensing optical element itself with respect to the second light flux is indicated by a square. As can be seen from FIG. 3 (d), the value of the chromatic aberration of the condensing optical element itself with respect to the first light beam is negative.
- the blazed diffraction structure DOE of the first correction element L1 is set so that the value of the chromatic aberration of the first correction element itself with respect to the first light beam is positive. Is designed.
- the chromatic aberration of the first condensing spot when using the optical pickup device can be obtained. It can be kept within the range necessary for reproduction and / or recording.
- the value of the chromatic aberration of the condensing optical element itself with respect to the second light beam is negative. Therefore, in the present embodiment, although not shown, the blazed diffraction structure DOE of the second correction element L2 is set so that the value of the chromatic aberration of the second correction element itself with respect to the second light flux is positive. Is designed.
- the chromatic aberration of the second condensed spot when using the optical pickup device can be obtained. It can be kept within the range necessary for reproduction and / or recording.
- the light source unit L integrating the second light source LD 2 and the third light source LD 3
- the diffraction structure provided in the second correction element L2 can be used to provide sufficient light for DVDs and CDs. A light quantity and aberration suppression function can be obtained.
- the second correction element L2 since the demand for chromatic aberration correction is lower than that of HD-DVD, the second correction element L2 does not have a diffraction structure, and the second correction element itself has chromatic aberration with respect to the second light beam. Even in the case of the configuration, the chromatic aberration of the second focused spot can be suppressed to a range necessary for reproducing and / or recording information. In this case, a large amount of light can be secured because no loss of light amount occurs when the second light beam passes through the diffraction zone.
- a diffraction structure is provided on the second correction element L2 and the objective lens OBJ. .
- FIG. 3 (e) is a diagram showing the value of the chromatic aberration of the condensing optical element itself for the first light beam and the second light beam, and the value of the chromatic aberration of the condensing optical element itself for the first light beam. Is indicated by a circle, and the value of the chromatic aberration of the condensing optical element itself with respect to the second light flux is indicated by a square. As can be seen from FIG. 3 (e), the value of the chromatic aberration of the condensing optical element itself with respect to the first light beam is positive. The light beam is offset by the value (negative) of the chromatic aberration of the first correction element itself.
- the value of the chromatic aberration of the condensing optical element itself with respect to the second light beam is negative. Therefore, in the present embodiment, although not shown, the blazed diffraction structure of the second correction element L2 is set so that the value of the chromatic aberration of the second correction element itself becomes positive for the second light flux. D ⁇ E is designed.
- the chromatic aberration of the second condensed spot when using the optical pickup device can be obtained. It can be kept within the range necessary for reproduction and / or recording.
- the first correction element L1 since the first correction element L1 does not have a diffractive structure, there is no loss of light amount when the first light beam passes through the first correction element, and workability is improved. Can be improved.
- FIG. 5 is a schematic diagram showing the structure of an optical pickup device PU 6 capable of appropriately recording and reproducing information on both HD—DVD (first optical information recording medium) and DVD (second optical information recording medium).
- FIG. 5 The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
- the optical pickup device PU 6 is a blue-violet semiconductor laser LD 1 (first light source) that emits a laser beam (a first light beam) of 407 nm and emits light when recording / reproducing information on an HD-DVD. ), Photodetector PD 1 for the first beam, Information recording for DVD Z
- a red semiconductor laser LD2 (second light source) that emits a laser beam (second light beam) of 655.5 nm that is emitted when performing reproduction, a photodetector PD2 for the second light beam, a first light beam and a second light beam
- An objective lens having a function of condensing each laser light beam on the information recording surfaces RL1 and RL2, a first correction element L1 through which the light beam passes, a second correction element L2 through which only the second light beam passes.
- (Condensing optical element) OB J consisting of the first beam splitter BS 1, the second beam splitter one BS 2, the third beam splitter BS 3, the aperture ST
- the first correction element Ll, the second correction element L2, and the objective lens OBJ are provided with diffraction structures.
- the blue-violet semiconductor laser LD1 is made to emit light, as shown by the ray path in FIG.
- the divergent light beam emitted from the blue-violet semiconductor laser LD 1 passes through the first beam splitter BS 1, is reflected by the second beam splitter BS 2, and then passes through the first correction element L 1 to be parallelized. After being converted into a light beam, it reaches the condensing optical element OBJ. .
- the n 1 (n 1 is a natural number) order diffracted light of the first light beam generated by receiving a diffraction action from the diffractive structure of the condensing optical element ⁇ BJ is transmitted to the information recording surface RL through the HD-DVD protective layer PL 1.
- a spot (first condensed spot) is formed by condensing light on top of 1.
- the chromatic aberration is suppressed within a range necessary for reproducing and / or recording information.
- the absolute value of the chromatic aberration of the first focused spot is 0.15 jtm / nm or less.
- the condensing optical element #BJ performs focusing / tracking by a two-axis actuator AC (not shown) arranged around the condensing optical element #BJ.
- Information recording surface RL 1 The reflected light flux modulated by the information pits passes through the condensing optical element OBJ and the first correction element L1 again, is reflected by the second beam splitter BS2, and is branched by the first beam splitter BS1. Astigmatism is given by the sensor lens SEN 1. The light converges on the light receiving surface of the photodetector PD 1. Then, information recorded on the HD-DVD can be read using the output signal of the photodetector PD1.
- the red semiconductor laser LD2 When information is recorded / reproduced on / from a DVD, first, the red semiconductor laser LD2 emits light, as shown by the optical path in FIG.
- the divergent light beam emitted from the red semiconductor laser LD2 passes through the second correction element L2, the third beam splitter BS3, and the second beam splitter BS2, and passes through the first correction element L1. After that, the light is converted into a parallel light beam, and then reaches the condensing optical element OBJ.
- the n 2 (n 2 is a natural number that is n 1 ⁇ n 2) order diffracted light of the second light beam generated by receiving a diffractive action from the diffractive structure of the condensing optical element OBJ passes through the DVD protective layer PL 2.
- a spot (second light spot) is formed by condensing light on the information recording surface RL2.
- the chromatic aberration is suppressed within a range necessary for reproducing and / or recording information.
- the absolute value of the chromatic aberration of the second focused spot is 0.25 / m / nm or less.
- the focusing optical element OB J performs focusing and tracking by a two-axis actuator AC arranged around the focusing optical element OB J.
- the reflected light flux modulated by the information pits on the information recording surface RL2 again passes through the condensing optical element OBJ, the first correction element Ll, the second beam splitter BS2, and the third beam splitter BS3.
- astigmatism is given by the sensor lens SEN 2 and converges on the light receiving surface of the photodetector PD 2.
- information recorded on the DVD can be read using the output signal of the photodetector PD2.
- the condensing optical element OBJ is a single-sided aspherical plastic lens having a function of condensing the first and second light beams on the information recording surfaces RL1 and RL2 of the optical disc. Note that a condensing optical element may be configured by combining a plurality of optical elements.
- a blazed diffraction structure DOE as shown in FIG. 2 is formed on the incident surface of the light-collecting optical element OBJ.
- the blazed diffraction structure DOE is provided to correct the chromatic aberration of the condensing optical element OBJ itself with respect to the light beam emitted from the second light source, and specifically, the absolute value of the chromatic aberration is 0. Designed to be less than 25 jU mZ nm .
- the first correction element L1 is a collimator that emits both the first light beam emitted as divergent light from the first light source LD1 and the second light beam emitted as divergent light from the second light source LD2 as parallel light. It has a function and a blaze-type diffraction structure DOE similar to that shown in FIG. 2 is formed on the exit surface.
- the second correction element L2 has a blazed diffraction structure DOE similar to that shown in FIG. 2 formed on the emission surface thereof. '
- FIG. 3 (b) is a diagram showing the value of the chromatic aberration of the condensing optical element itself for the first light beam and the second light beam, and the value of the chromatic aberration of the condensing optical element itself for the first light beam. Is indicated by a circle, and the value of the chromatic aberration of the condensing optical element itself with respect to the second light flux is indicated by a square.
- the absolute value of the chromatic aberration of the condensing optical element with respect to the second light flux is 0.25 m / nm due to the blazed diffraction structure DOE formed in the condensing optical element OBJ. Below, it can be seen that it is almost zero.
- the blazed diffractive structure DOE of the condensing optical element OBJ is designed so that the chromatic aberration of the condensing optical element itself with respect to the second light beam is almost zero, the first light beam is used as shown in Fig. 3 (b). Chromatic aberration of the condensing optical element itself remains, The value of the difference is positive.
- the blazed diffraction structure DOE of the first correction element L1 is set so that the value of the chromatic aberration of the first correction element itself becomes negative with respect to the first light flux. Is designed.
- the chromatic aberration of the first condensing spot when using the optical pickup device can be obtained. It can be kept within the range necessary for reproduction and / or recording.
- the blazed diffraction structure DOE of the first correction element L1 is designed so that the value of the chromatic aberration of the first correction element itself becomes negative with respect to the first light flux, the first correction is performed also for the second light flux.
- the chromatic aberration of the element itself remains, and specifically, the value of the chromatic aberration becomes negative.
- the second correction element itself for the second light beam has a blazed diffraction structure of the second correction element L2 so that the value of chromatic aberration is positive.
- D ⁇ E is designed.
- the chromatic aberration of the second condensing spot at the time of using the optical pickup device is obtained. Can be kept within the range necessary for reproduction and / or recording.
- n1 and n2 (0, 1), (2, 1), (3, 2), (5, 3), (8, 5). It is preferable to be either.
- the first correction element L1, the second correction element L2, and the objective lens ⁇ BJ are provided with diffraction structures.
- a blazed diffraction structure DOE as shown in FIG. 2 is formed on the incident surface of the light collecting optical element OBJ.
- the blazed diffraction structure DOE is provided to correct the chromatic aberration of the light collecting optical element OBJ itself with respect to the light beam emitted from the first light source.
- the absolute value of the chromatic aberration is 0. . Designed to be less than 15 jUmZnm.
- FIG. 3 (a) is a diagram showing the value of the chromatic aberration of the condensing optical element itself with respect to the first light beam and the second light beam, and the value of the chromatic aberration of the condensing optical element itself with respect to the first light beam. Is indicated by a circle, and the value of the chromatic aberration of the condensing optical element itself for the second light flux is indicated by a square. From FIG. 3 (a), the absolute value of the value of the chromatic aberration of the condensing optical element itself with respect to the first light beam is determined by the blazed diffraction structure DOE formed in the condensing optical element as described above. It turns out that it is less than 0.15 mZnm, that is, almost zero.
- the absolute value of the chromatic aberration of the first correction element itself with respect to the first and first light beams is also obtained by the blazed diffraction structure DOE formed in the first correction element. 2. It is less than l ⁇ m / Znin, that is, almost zero.
- the chromatic aberration of the condensing optical element itself and the chromatic aberration of the first correcting element itself for the first light flux substantially zero, the chromatic aberration of the first condensed spot at the time of using the optical pickup device can be reproduced and reproduced. Alternatively, it can be kept within the range necessary for recording. '' Also, focus so that the chromatic aberration of the focusing optical element itself for the first light beam is almost zero. Since the blazed diffractive structure DOE of the optical element is designed, as shown in Fig. 3 (a), the chromatic aberration of the condensing optical element itself remains for the second light beam, and specifically, the value of the chromatic aberration Becomes negative.
- the blazed diffraction structure DOE of the first correction element L1 is designed so that the value of the chromatic aberration of the first correction element itself with respect to the first light flux becomes substantially zero, In this case, the chromatic aberration of the first correction element itself remains, and specifically, the value of the chromatic aberration becomes negative.
- the blazed diffraction structure DOE of the second correction element L2 is set so that the value of the chromatic aberration of the second correction element itself with respect to the second light flux is positive. Is designed.
- the negative chromatic aberration of the condensing optical element itself and the negative chromatic aberration of the first correction element itself with respect to the second light beam are offset by the positive chromatic aberration of the second correction element itself.
- the chromatic aberration of the second condensed spot at the time can be suppressed within a range necessary for reproducing and / or recording information.
- the condensing optical element itself for the first light beam and the first correction element By suppressing the chromatic aberration itself to almost zero, it is possible to prevent the wavefront aberration from deteriorating even if the wavelength fluctuates during tracking during reproduction and / or recording of an HD-DVD.
- This embodiment is different from the fourth embodiment in that the condensing optical element for the first light beam is By canceling the negative chromatic aberration of the body by the positive chromatic aberration of the first correction element itself, the chromatic aberration of the first condensed spot when using the optical pickup device is kept within the range necessary for reproducing and recording information. Also, by canceling the negative chromatic aberration of the condensing optical element itself with respect to the second light beam by the positive chromatic aberration of the second correcting element itself, the chromatic aberration of the second condensed spot when using the optical pickup device can be obtained.
- the present invention relates to an optical pickup device in which reproduction and / or recording of an optical pickup is limited to a range necessary for the reproduction and / or recording.
- Tables 1 and 2 show the lens data of each optical element.
- the image-side numerical aperture NA 3 is set to 0.53.
- the exit surface (the fourth surface) of the first correction element, the entrance surface (the third surface) and the exit surface (the fourth surface) of the second correction element, and the condensing optical element (the objective lens) A blaze-type diffraction structure is formed on the incident surface (Sixth surface) of.
- the magnification ml and m2 of the objective lens with respect to the first light beam and the second light beam are almost 0, the first light beam and the second light beam enter the objective lens as parallel light, and the magnification m3 with respect to the third light beam is It is negative, and the third light flux is incident on the objective lens as divergent light.
- the incident surface (Sixth surface) and the outgoing surface (Seventh surface) of the optical axis around the optical axis L which are defined by the following equations (Equation 1) and are substituted by the coefficients shown in Tables 1 and 2, respectively. Is formed on an aspherical surface which is axially symmetric.
- X (h) is the axis in the optical axis direction (the traveling direction of the light is positive)
- ⁇ is the cone coefficient
- a 2i is the aspheric coefficient.
- the pitch of the diffraction ring zone is defined by an equation obtained by substituting the coefficients shown in Table 2 into the optical path difference function of Equation (2).
- B 2i is the coefficient of the optical path difference function
- ⁇ is the wavelength used
- the chromatic aberration of the condensing optical element itself and the chromatic aberration of the first correction element itself with respect to the first light beam are both substantially zero.
- the chromatic aberration of the first condensing spot is kept within the range required for reproducing and / or recording information, and the negative chromatic aberration of the condensing optical element itself with respect to the second light beam is corrected by the positive of the second correction element itself.
- the present invention relates to an optical pickup device in which the chromatic aberration of the second condensed spot during use of the optical pickup device is suppressed to a range necessary for reproducing and / or recording information by canceling out the chromatic aberration of the optical pickup device.
- Tables 3 and 4 show the lens data of each optical element. '
- the exit surface (the fourth surface) of the first correction element, the exit surface (the fourth surface) of the second correction element, and the entrance surface (the sixth surface) of the condensing optical element (objective lens) are used.
- a blazed diffraction structure is formed in the figure.
- the magnification ml and m2 of the objective lens with respect to the first light beam and the second light beam are almost 0, the first light beam and the second light beam enter the objective lens as parallel light, and the magnification m3 with respect to the third light beam is It is negative, and the third light flux is incident on the objective lens as divergent light.
- the entrance surface (Sixth surface) and the exit surface (Seventh surface) of the optical axis are defined by equations obtained by substituting the coefficients shown in Tables 3 and 4 into Equation 1 above, respectively, and are symmetric about the optical axis L. It is formed in a suitable aspherical surface.
- the pitch of the diffraction ring zone is defined by an equation obtained by substituting the coefficients shown in Table 4 into the optical path difference function of Equation 2 above.
- Tables 5 and 6 show lens data for each optical element.
- Mi represents the displacement from the i-th surface to the (i + 1) -th surface.
- the emission surface (the fourth surface) of the first correction element, the emission surface (the fourth surface) of the second correction element, and the incidence surface (the sixth surface) of the condenser optical element (the objective lens) A blazed diffraction structure is formed on the substrate.
- magnification ml and m 2 of the objective lens with respect to the first light flux and the second light flux are almost 0, and the first ′ light flux and the second light flux enter the objective lens as parallel light, and the magnification m 3 with respect to the third light flux. Is negative, and the third light flux is incident on the objective lens as divergent light.
- the incident surface (Sixth surface) and the outgoing surface (Seventh surface) of the optical axis around the optical axis L are defined by the mathematical formulas obtained by substituting the coefficients shown in Tables 5 and 6 into Equation 1 above. It is formed on an axisymmetric aspheric surface.
- the pitch of the diffraction ring zone is defined by an equation obtained by substituting the coefficients shown in Table 6 into the optical path difference function of the above equation (2).
- This embodiment is different from the sixth embodiment in that the condensing optical element for the second light beam is self-contained.
- the chromatic aberration of the body is almost zero, and the negative chromatic aberration of the first correction element itself with respect to the second light beam is canceled out by the positive chromatic aberration of the second correction element itself, so that the second condensing spot when using the optical pickup device.
- the present invention relates to an optical pickup device in which the chromatic aberration of a first focusing spot during use of an optical pickup device is kept within a range necessary for reproducing and recording information.
- Tables 7 and 8 show the lens data of each optical element.
- Mi represents the displacement from the i-th surface to the (i + 1) -th surface.
- Optical path difference function C2 2.6331E-02 DVD: First-order blazed wavelength 661 nm) C4 1.2847E-04
- the exit surface (the sixth surface) of the first correction element, the exit surface (the second surface) of the second correction element, and the entrance surface (the eighth surface, A blazed diffraction structure is formed on the (8'th surface).
- the outgoing surface (Sixth surface) of the first correction element, the incoming surface (Eighth and Eighth 'surfaces) and the outgoing surface (Ninth surface) of the condensing optical element (Objective lens) correspond to Equation 1 above, respectively. It is formed on an aspherical surface that is axisymmetric about the optical axis L, which is defined by a mathematical expression in which the coefficients shown in Tables 7 and 8 are substituted.
- the pitch of the diffraction ring zone is defined by a mathematical expression obtained by substituting the coefficients shown in Table 8 into the optical path difference function of the above equation (2).
- both the chromatic aberration of the condensing optical element itself and the chromatic aberration of the first correction element itself with respect to the first light beam are substantially zero.
- the chromatic aberration of the first condensing spot during use is kept within the range required for reproducing and / or recording information, and the negative chromatic aberration of the condensing optical element itself with respect to the second light beam and the negative chromatic aberration of the first correction element itself are reduced.
- Optical pickup device that suppresses the chromatic aberration of the second condensed spot when the optical pickup device is used by suppressing the chromatic aberration of the second correction element itself by the positive chromatic aberration of the second correction element itself. It is about.
- Tables 9 and 10 show the lens data of each optical element.
- wavelength ⁇ 1 was 407 nm.
- the output surface (sixth surface) of the first correction element and the second correction element is the output surface (sixth surface) of the first correction element and the second correction element
- a blazed diffraction structure is formed on the exit surface (second surface) and the incident surface (eighth surface) of the condenser optical element (objective lens).
- the magnification ml and m 2 of the objective lens with respect to the first light beam and the second light beam are almost 0, and the first light beam and the second light beam are incident on the objective lens as parallel light.
- the exit surface (Sixth surface) of the first correction element, the entrance surface (Sixth surface) of the condensing optical element (Objective lens), and the exit surface (Ninth surface) are as shown in Table 9 above.
- an aspheric surface symmetric with respect to the optical axis L which is defined by a mathematical expression into which the coefficients shown in Table 10 are substituted.
- the pitch of the diffraction ring zone is defined by an equation obtained by substituting the coefficients shown in Table 10 into the optical path difference function of the above equation (2).
- Table 11 shows chromatic aberration (referred to as HD-DVD) with respect to the first light flux when the objective lens and the first correction element are combined in Examples 1 to 3, and the objective lens and the second correction element. 13 shows chromatic aberration (denoted as DVD) with respect to the second light flux in the case where is combined. [Table 11]
- Example 3 From Table 11, it can be seen that in Examples 1 to 3, the chromatic aberration of HD DVD and DVD was suppressed to a range that would not hinder practical use.
- Table 12 shows the chromatic aberration (referred to as HD-DVD) for the first luminous flux when the objective lens and the first correction element are combined in Examples 4 and 5.5, and the objective lens and the first correction.
- 9 shows chromatic aberration (denoted as DVD) with respect to the second light flux when the element and the second correction element are combined.
- Table 1 2 the chromatic aberration for the first luminous flux when the objective lens and the first correction element are combined in Examples 4 and 5.5
- the high-density optical disk is HD-D, but the high-density optical disk is not limited to HD-DVD.
Abstract
Description
Claims
Priority Applications (1)
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JP2005515215A JP4730099B2 (ja) | 2003-11-04 | 2004-10-28 | 光ピックアップ装置 |
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JP2003374616 | 2003-11-04 | ||
JP2003-374616 | 2003-11-04 |
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WO2005043522A1 true WO2005043522A1 (ja) | 2005-05-12 |
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PCT/JP2004/016366 WO2005043522A1 (ja) | 2003-11-04 | 2004-10-28 | 光ピックアップ装置、及び光ピックアップ装置に用いる補正素子 |
Country Status (8)
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US (1) | US7304935B2 (ja) |
EP (1) | EP1530207B1 (ja) |
JP (1) | JP4730099B2 (ja) |
KR (1) | KR20060115863A (ja) |
CN (1) | CN100527239C (ja) |
DE (1) | DE602004026021D1 (ja) |
TW (1) | TW200526979A (ja) |
WO (1) | WO2005043522A1 (ja) |
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JP4339182B2 (ja) * | 2004-05-28 | 2009-10-07 | 株式会社リコー | 光ピックアップとこれを用いた光情報処理装置 |
EP2963475A4 (en) * | 2013-02-28 | 2016-10-26 | Olympus Corp | SAMPLE MONITORING PROCEDURE AND SAMPLE MONITORING DEVICE |
Citations (5)
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JP2000090477A (ja) * | 1998-09-09 | 2000-03-31 | Pioneer Electronic Corp | 光ピックアップ、情報再生装置及び情報記録装置 |
JP2001043559A (ja) * | 1999-07-30 | 2001-02-16 | Matsushita Electric Ind Co Ltd | 光ヘッド及び光ディスク装置 |
JP2001060336A (ja) * | 1998-10-28 | 2001-03-06 | Matsushita Electric Ind Co Ltd | 光学ヘッド |
JP2001093179A (ja) * | 1999-09-21 | 2001-04-06 | Pioneer Electronic Corp | 光ピックアップ |
JP2001209966A (ja) * | 2000-01-26 | 2001-08-03 | Pioneer Electronic Corp | 光ピックアップ |
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US6556533B1 (en) * | 1996-10-01 | 2003-04-29 | Matsushita Electric Industrial Co., Ltd. | Optical pickup device |
TW479253B (en) * | 1998-12-17 | 2002-03-11 | Konishiroku Photo Ind | Objective lens for correcting chromatic aberration for use in recording toor reproducing from optical information recording medium and optical pickup apparatus therewith |
ATE441183T1 (de) * | 1999-01-22 | 2009-09-15 | Konica Minolta Opto Inc | Optische abtastvorrichtung, mit der optischen abtastvorrichtung versehenes aufnahme/wiedergabegerät, optisches element und verfahren zur datenaufnahme/wiedergabe |
JP2001067701A (ja) * | 1999-08-31 | 2001-03-16 | Sony Corp | 光学ヘッド、記録再生装置及び光学ヘッドの駆動方法 |
JP4070936B2 (ja) * | 2000-04-14 | 2008-04-02 | ペンタックス株式会社 | 光ヘッド用対物光学系 |
JP2001305325A (ja) * | 2000-04-26 | 2001-10-31 | Konica Corp | 光ピックアップ装置用光学素子および光学素子 |
JP4610118B2 (ja) * | 2001-03-30 | 2011-01-12 | Hoya株式会社 | 光ヘッド用対物レンズ |
JP2003287675A (ja) * | 2002-01-22 | 2003-10-10 | Konica Corp | 集光光学系、光ピックアップ装置、記録・再生装置、収差補正素子及び対物レンズ |
AU2003207160A1 (en) * | 2002-03-06 | 2003-09-16 | Matsushita Electric Industrial Co., Ltd. | Optical head device and optical information device using this, and computer, optical disk player, car navigation system, optical disy recorder and optical disk server using this optical information device |
-
2004
- 2004-10-28 CN CNB2004800316329A patent/CN100527239C/zh not_active Expired - Fee Related
- 2004-10-28 JP JP2005515215A patent/JP4730099B2/ja not_active Expired - Fee Related
- 2004-10-28 WO PCT/JP2004/016366 patent/WO2005043522A1/ja active Application Filing
- 2004-10-28 KR KR1020067008437A patent/KR20060115863A/ko not_active Application Discontinuation
- 2004-10-29 TW TW093132983A patent/TW200526979A/zh unknown
- 2004-11-01 EP EP04256727A patent/EP1530207B1/en not_active Not-in-force
- 2004-11-01 DE DE602004026021T patent/DE602004026021D1/de active Active
- 2004-11-01 US US10/976,845 patent/US7304935B2/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2000090477A (ja) * | 1998-09-09 | 2000-03-31 | Pioneer Electronic Corp | 光ピックアップ、情報再生装置及び情報記録装置 |
JP2001060336A (ja) * | 1998-10-28 | 2001-03-06 | Matsushita Electric Ind Co Ltd | 光学ヘッド |
JP2001043559A (ja) * | 1999-07-30 | 2001-02-16 | Matsushita Electric Ind Co Ltd | 光ヘッド及び光ディスク装置 |
JP2001093179A (ja) * | 1999-09-21 | 2001-04-06 | Pioneer Electronic Corp | 光ピックアップ |
JP2001209966A (ja) * | 2000-01-26 | 2001-08-03 | Pioneer Electronic Corp | 光ピックアップ |
Also Published As
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KR20060115863A (ko) | 2006-11-10 |
JPWO2005043522A1 (ja) | 2007-05-10 |
CN100527239C (zh) | 2009-08-12 |
DE602004026021D1 (de) | 2010-04-29 |
EP1530207A3 (en) | 2007-10-10 |
US7304935B2 (en) | 2007-12-04 |
TW200526979A (en) | 2005-08-16 |
EP1530207A2 (en) | 2005-05-11 |
US20050094538A1 (en) | 2005-05-05 |
CN1875412A (zh) | 2006-12-06 |
JP4730099B2 (ja) | 2011-07-20 |
EP1530207B1 (en) | 2010-03-17 |
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