WO2002041303A2 - Optical scanning device - Google Patents
Optical scanning device Download PDFInfo
- Publication number
- WO2002041303A2 WO2002041303A2 PCT/EP2001/013045 EP0113045W WO0241303A2 WO 2002041303 A2 WO2002041303 A2 WO 2002041303A2 EP 0113045 W EP0113045 W EP 0113045W WO 0241303 A2 WO0241303 A2 WO 0241303A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- wavelength
- diffractive
- optical
- record carriers
- radiation
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—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
-
- 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
-
- 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
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
- G02B2003/0093—Simple or compound lenses characterised by the shape
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B2007/0003—Recording, reproducing or erasing systems characterised by the structure or type of the carrier
- G11B2007/0006—Recording, reproducing or erasing systems characterised by the structure or type of the carrier adapted for scanning different types of carrier, e.g. CD & DVD
Definitions
- the present invention relates to an optical scanning device comprising an optical objective lens. More specifically, but not exclusively, the invention relates to an optical scanning device capable of writing and reading data from two different types of optical record carriers, such as compact discs (CDs) and digital versatile discs (DNDs), with laser radiation of a different wavelength, respectively, using the same optical objective lens system.
- CDs compact discs
- DNDs digital versatile discs
- CDs are available, inter alia, as CD- As (CD-audio), CD-ROMs (CD-read only memory) and CD-Rs (CD-recordable).
- CDs are designed to be scanned with a wavelength of about 780nm and a numerical aperture ( ⁇ A) of 0.45
- DVDs are designed to be scanned at a wavelength in the region of 660nm. For reading DNDs an ⁇ A of 0.6 is generally used, whereas for writing DNDs an ⁇ A of 0.65 is generally required.
- DNDs and CDs differ in the thickness of their transparent substrates, " providing different information layer depths.
- the information layer depth for DND is about 0.6mm, whereas the depth for CD is about 1.2mm.
- ⁇ A numerical aperture
- CD-Rs are to be scanned by the optical scanning device
- a 780nm laser beam has to be applied, because the CD-R is designed for writing and reading specifically at that wavelength.
- organic dye is used as a recording film, of which the reflection characteristics change significantly with wavelength. It is difficult to achieve sufficient modulation for reflected radiation of 660nm to reconstruct the information stored on a CD-R.
- Using a 780nm laser beam and an ⁇ A of 0.45 for reading CDs with the same objective lens as used for DND causes a large spherical aberration.
- spherical aberration has to be compensated in some way in order to achieve an optical storage device capable of reading and/or recording CD-R, CD-ROM and DND using laser radiation of 660nm and 780nm with a single optical objective lens.
- Systems capable of reading DND and CD by using laser radiation of different wavelength with the same objective lens are known in the art.
- WO 99/57720 describes such a system, which uses a moulded plastic lens having either two refractive aspheric surfaces or one aspherical surface and one refractive spherical surface including a diffractive element.
- the lens is capable of correcting for spherical aberration caused by the difference in thickness for the two disc formats as well as for chromatic aberration.
- plastic has large temperature sensitivity and its large dispersion or, equivalently, low Abbe number.
- the refractive index change for plastic as a function of temperature is about ten times larger than for that glass.
- Large dispersion means large sensitivity to wavelength variation.
- a spread in laser wavelength for mass produced lasers there are several sources of wavelength change: A spread in laser wavelength for mass produced lasers
- a diffractive/refractive hybrid lens for use in an optical data storage system is described, which is made of a high dispersive glass with thus a low Abbe number.
- the resulting increased longitudinal chromatic aberration is compensated by the diffractive lens element.
- the described objective lens is for example able to correct for wavelength variations over a 20nm wavelength range and up to lOnm bandwidth of a laser diode.
- the lens is not capable of reading and writing data from optical record carriers of different thicknesses.
- a diffractive multi-focal objective lens is described.
- a first focal point is formed by radiation of a lower diffractive order, whereas radiation of a higher diffractive order converges at a second focal point on the optical axis nearer to the lens than the first focal point.
- the lens compensates for chromatic aberration and is thus capable of writing and reading data from optical discs with different thicknesses of the transparent substrate.
- the system is not designed for the use of radiation of two different wavelengths as it is needed to be able to scan data on DND, CD-A, CD-R and CD- ROM formats with the same objective lens in an optical scanning device.
- EP 936604 describes an optical pickup device suitable for reading and writing discs of DND, CD-R and CD-ROM format with laser radiation of two different wavelengths.
- an optical element having a first diffractive element in its central region and a second diffractive element with a different grating structure in its peripheral region is used in addition to an objective lens.
- a stepped grating profile has been chosen as a diffractive element.
- the central region of the optical element allows transmission of laser radiation of a first wavelength without any change and increases the diameter of laser radiation of a second wavelength.
- the peripheral region again allows transmission of laser radiation of the first wavelength without any change and simultaneously prevents the radiation of the second wavelength from contributing to the spot formation. In this way the ⁇ A for use of radiation of the second wavelength is reduced to a desired value.
- a stepped grating profile has been chosen which is usually manufactured in a photolithographic process. It is difficult to manufacture stepped grating profiles of small dimension in a replication process. It is a further disadvantage of the system described, that the additional optical element comprises two regions with different diffractive properties, which makes manufacturing of such a device more complicated. 1 ] It is an object of the invention to provide improved optical scanning devices for scanning optical record carriers.
- an optical scanning device for scanning first and second optical record carriers with a first and a second information layer depth by radiation of a first wavelength ⁇ i, and a second wavelength ⁇ 2 , respectively, wherein, preferably, 620nm ⁇ ⁇ ⁇ 700nm and 740nm ⁇ ⁇ 2 ⁇ 820nm, said device being capable of reading and writing optical record carriers of said first format, the device including an objective lens (10) with at least one refractive element and at least one diffractive element (11) and with a numerical aperture NA of NA > 0.60 for said first wavelength ⁇ i, said diffractive element including a pattern of generally sawtooth-like elements; wherein the diffractive and refractive properties of the objective lens are selected: such that radiation of said first wavelength is transmitted and focused on optical record carriers of said first thickness; such that radiation of said second wavelength is transmitted and focused on optical record carriers of said second thickness; and such that a variation in wavelength of 5nm results in spherochromatism below 0.
- an optical scanning device capable of scanning data on record carriers of a first and second thickness with a first and second wavelength respectively.
- the objective lens is designed to change a parallel beam of wavelength into a converging beam of NA > 0.60, which ensures that the system is capable of writing data with a high density.
- the present invention is capable of providing a scanning device with the following features: the system is capable of writing data to record carriers of a first format because it is corrected for chromatic aberration resulting from fast wavelength variations during write operations; it has a diffractive element with a generally sawtooth-like pattern, such that it may for example be manufactured in a single-step replication process; the system has high efficiency for scanning first optical record carriers (e.g. DNDs) and acceptable efficiency for scanning second optical record carriers (e.g. CDs); and the lens provides limited spherochromatism and the system is thus able to cope with wavelength variations.
- DNDs optical record carriers
- CDs acceptable efficiency for scanning second optical record carriers
- the sawtooth-like pattern elements have a width of at least lO ⁇ m. This ensures an easy manufacturability in a single-step replication process.
- the grating structure may be incorporated into the mould by a finite-sized turning tool.
- Figure 1 is a schematic illustration of components of a scanning device for optical record carriers according to one embodiment of the present invention
- Figure 2a is a schematic illustration of a single objective lens for use in a scanning device capable of scanning optical record carriers of a first thickness with laser radiation of a first wavelength and a first numerical aperture and record carriers of a second format with laser radiation of a second wavelength and a second numerical aperture;
- Figure 2b is a schematic illustration of the front view of the objective lens, showing the ring-shaped diffractive structure.
- Figure 1 is a schematic illustration of components common to a device in accordance with the embodiment, to be described below, for scanning an optical record carrier 1.
- the record carrier 1 is in this embodiment an optical disc as will be described, by way of example, below.
- the optical disc 1 comprises a transparent layer 2, on one side of which at least one information layer 3 is arranged.
- the side of the information layer facing away from the transparent layer is protected from environmental influences by a protection layer 4.
- the side of the transparent layer facing the device is the disc entrance face 5.
- the transparent layer 2 acts as a substrate for the optical disc by providing mechanical support for the information layer or layers.
- the transparent layer 2 may have the sole function of protecting the information layer 3, while the mechanical support is provided by a layer on the other side of the information layer, for instance by the protection layer 4 or by a further information layer and transparent layer connected to the uppermost information layer.
- Information may be stored in the information layer 3, or information layers, of the optical disc in the form of optically detectable marks arranged in substantially parallel, concentric or spiral tracks, not indicated in Figure 1.
- the marks may be in any optically readable form, e.g. in the form of pits, or areas with a reflection coefficient or a direct of magnetisation different from their surroundings, or a combination of these forms.
- the scanning device includes a radiation source 6, comprising a tunable semiconductor laser or two separate semiconductor lasers, emitting radiation of a first wavelength and of a second wavelength in a diverging fadiation beam 7 towards a lens system.
- the lens system includes a collimator lens 9 and an objective lens 10 arranged along optical axis 13.
- the collimator lens 3 transforms the diverging beam 7 emitted from the radiation source 6 into a substantially collimated beam 15.
- the objective lens 10 comprises a diffractive element, which is indicated in the drawing by the pattern 111 and will be described in more detail below.
- the objective lens 10 transforms the incident collimated radiation beam 15 into a converging beam 14, having a selected NA, which comes to a spot 18 on the information layer 3.
- a detection system 16, a second collimator lens 19 and a beam splitter 8 are provided in order to detect data signals, and focus error signals which are used to mechanically adjust the axial position of the objective lens 10.
- the diffractive grating 11 as shown in Figures 1 and 2A is arranged on the side of the objective lens 10 facing the radiation source. However, it may alternatively be arranged on the other surface of lens 10.
- Figure 2a is a schematic illustration of the objective lens 10 for use in the scanning device described above.
- the scanning device is capable of scanning optical record carriers with a first thickness of the transparent substrate with laser radiation 21 of a first wavelength ⁇ i at a first numerical aperture NAi.
- the device is further capable of scanning record carriers with a second thickness of the transparent layer with laser radiation 23 of a second wavelength ⁇ 2 at a second numerical aperture NA 2 using the same optical objective lens 10.
- a numerical aperture of about 0.6 is used for reading DND and an ⁇ A above 0.6, preferably approximately 0.65, is applied for writing DVD.
- the objective lens 10 corrects for spherical aberration caused by the difference in thickness 31 and 33 of the transparent layers of a DND and CD carrier, respectively.
- the lens similarly corrects for spherochromatism and chromatic aberration as will be described in more detail below.
- a hybrid lens i.e. a lens combining diffractive and refractive elements, in an infinite-conjugate mode.
- a hybrid lens can be formed by applying a grating profile on one of the surfaces of a refractive lens.
- a robust and inexpensive solution which is easy to manufacture can be achieved by incorporating the diffractive structure into the mould by means of diamond turning. In this way the lens can be manufactured in a single step replication process.
- the tip dimension of a diamond turning device is typically around 5 ⁇ m.
- FIG. 2b is a schematic front view of the objective lens 10 illustrating the diffractive structure according to a preferred embodiment of the invention. It can be seen that a circular grating structure has been applied with a pattern of coaxially ring-shaped pattern elements with gradually increasing width towards the centre of the lens. Each pattern element defines a so-called zone of the diffractive element.
- Scanning data with radiation of wavelength ⁇ i and ⁇ 2 using a single objective lens may for example be achieved by designing the diffractive element of the objective lens in a way that radiation ⁇ i of a selected first diffractive order and radiation ⁇ of a selected second diffractive order is used for spot formation.
- a stepped grating structure By applying a stepped grating structure radiation of a certain wavelength may be transmitted through the diffractive element ideally without diffraction and thus the fully transmitted zeroth diffractive order can be used to scan data with this wavelength.
- the structures of such a stepped grating profile are much smaller compared to a sawtooth-like grating profile. Manufacturing of such a stepped grating structure for example in a single step replication process would cause losses in transmission efficiency due to roundings of the structure because of the finite tip dimensions of the diamond turning tool. Therefore a sawtooth-like blazed grating structure has been chosen for the embodiments described below. In this case higher diffractive orders mi and m 2 (mi, > 0) are used for scanning with radiation of wavelengths ⁇ i and ⁇ . In the following a lens design according to embodiments of the invention will be described.
- equation (2) can be approximated by
- an achromatic hybrid lens may be designed by combining refractive and diffractive elements.
- KQ be the power of the diffractive lens K ⁇ the power of the refractive lens.
- the grating profile should extend over the full aperture used for ⁇ - radiation and should not be limited to the smaller ⁇ aperture.
- the range of possible wavelength variations introduces an amount of defocus that can be corrected mechanically by a lens actuator.
- the overall dispersion is much larger.
- a lens with its diffractive element limited to the central region of the ⁇ aperture would experience different amounts of defocus in this central region and the peripheral region. For scanning data with radiation of ⁇ i, both the central region and the peripheral region are being used, and to avoid spot deterioration, the diffractive element is thus extended over the full aperture.
- the spherical aberration caused by the disc thickness difference is compensated for by spherical aberration introduced by the diffractive element resulting from the use of wavelengths ⁇ j and ⁇ 2 and diffractive orders mi and m .
- the main term contributing to the spherical aberration generated by the diffractive element (having weak power) is
- the sensitivity of the system to wavelength variations is also preferably limited.
- the spread in wavelength due to manufacturing tolerances for mass produced laser is about 5 to lOnm.
- this not only causes defocus due to a change in power of the lens, but also spherochromatism.
- the root mean square of the optical path difference (OPD) introduced by the spherochromatism by wavelength variation ⁇ for radiation of diffractive order m ⁇ is given by
- the coefficient A In order to have positive zone spacings (r x > 0) the coefficient A must be positive. Furthermore, the power KQ of the diffractive element is given by ._ ⁇ A. fflA , - ⁇ .
- the zone spacing is larger when A/G ⁇ 0 than when A/G > 0.
- a larger zone spacing is preferable because it makes manufacturing of the element more efficient.
- Optical objective lenses are then designed with help of a commercially available lens design software, such as ZEMAXTM, whereby the diffractive orders mi and m 2 used to scan at wavelengths ⁇ ] and ⁇ are selected in accordance to the solution given in equation (17).
- a set of parameters like the wavelengths ⁇ i and ⁇ 2 , the focal length F, the dimensions of the lens, etc., are specified and the lens design is optimised by the program using a derived merit function to minimise the resulting amount of defocus due to fast wavelength variations, spherical aberration and spherochromatism.
- Discs of DVD and CD format are made of polycarbonate and have a refractive index of 1.5796 at ⁇ i and 1.5733 at ⁇ 2 .
- the objective lens has in all five embodiments one aspherical and one planar surface.
- the aspherical surface is realised by applying a thin acrylic layer on top of a glass lens body with a convex surface.
- the free working configuration is listed in Table 2 for the five examples.
- the lens has a thickness on the optical axis of 2.53nm and an entrance pupil diameter of 3.58mm.
- the convex surface of the lens body which is directed towards the collimator lens has a radius of 2.43mm.
- the thickness of this layer on the optical axis is 19 ⁇ m.
- the coefficients A and G preferably fulfil the following conditions: 10 /(E • mm) ⁇ ⁇ A ⁇ ⁇ 1000 /(E • mm) ;
- coefficients A and G are in the following ranges: 50 /( • mm) ⁇ ⁇ A ⁇ ⁇ 500 /(E • mm) and 200/ E 4 ⁇ G - (m 2 - ⁇ .TO J ⁇ 2
- the entrance pupil diameter epa ⁇ and the free working distance fwd 2 are listed in Table 2 for the five different examples.
- the first column gives the diffractive orders m ⁇ and m 2 used for the first and second wavelengths ⁇ i and ⁇ 2 , respectively.
- the resulting values are all below O.Q ⁇ ⁇ .
- the fourth and sixth column the diffraction efficiencies for radiation of the two wavelengths and ⁇ 2 are given.
- the fifth column gives the amount of higher order aberration due to the disc thickness difference for scanning at a wavelength ⁇ 2 . Again the resulting values are below 0.03 ⁇ 2 , which ensures proper scanning of record carriers with radiation of wavelength ⁇ 2 .
- the seventh and eighth column the total number of zones of the objective lens and the zone spacing of the smallest zone are given. Whilst in the above described embodiment a scanning device for scanning carriers of DND and CD format is described, it is to be appreciated that the scanning device can be alternatively used for any other types of optical record carriers to be scanned. Whilst in the above described embodiment 660nm and 780nm laser radiation is used, it is to be appreciated that radiation of any other combinations of wavelengths suitable for scanning optical record carriers may be used.
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- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Head (AREA)
- Lenses (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP01996853A EP1338008A2 (en) | 2000-11-14 | 2001-11-08 | Optical scanning device |
US10/169,926 US6751021B2 (en) | 2000-11-14 | 2001-11-08 | Optical scanning device |
JP2002543429A JP4162996B2 (en) | 2000-11-14 | 2001-11-08 | Optical scanning device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP00203998 | 2000-11-14 | ||
EP00203998.0 | 2000-11-14 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2002041303A2 true WO2002041303A2 (en) | 2002-05-23 |
WO2002041303A3 WO2002041303A3 (en) | 2002-09-06 |
Family
ID=8172271
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2001/013045 WO2002041303A2 (en) | 2000-11-14 | 2001-11-08 | Optical scanning device |
Country Status (6)
Country | Link |
---|---|
US (1) | US6751021B2 (en) |
EP (1) | EP1338008A2 (en) |
JP (1) | JP4162996B2 (en) |
KR (1) | KR100834864B1 (en) |
CN (1) | CN1206642C (en) |
WO (1) | WO2002041303A2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1302938A2 (en) * | 2001-10-11 | 2003-04-16 | Konica Corporation | Optical pickup device and objective lens used in the same |
EP1447798A2 (en) * | 2003-02-14 | 2004-08-18 | Konica Minolta Holdings, Inc. | Objective lens for optical pickup apparatus, optical pickup apparatus and optical information recording reproducing apparatus |
WO2008065573A1 (en) * | 2006-11-27 | 2008-06-05 | Koninklijke Philips Electronics N.V. | Lens system for scanning device |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100813945B1 (en) * | 2001-08-13 | 2008-03-14 | 삼성전자주식회사 | Optical pickup and recording medium applied on it |
JP2003296961A (en) * | 2002-04-03 | 2003-10-17 | Konica Corp | Optical pickup device and objective lens for optical pickup device |
SE524828C2 (en) * | 2002-06-06 | 2004-10-12 | Alfa Exx Ab | Resonator |
JP2005209295A (en) * | 2004-01-23 | 2005-08-04 | Sankyo Seiki Mfg Co Ltd | Optical head device |
JP4654350B2 (en) * | 2004-12-13 | 2011-03-16 | Hoya株式会社 | Scanning optical system |
DE602006003308D1 (en) * | 2005-01-11 | 2008-12-04 | Koninkl Philips Electronics Nv | OPTICAL SENSING DEVICE |
US7830772B2 (en) * | 2007-08-21 | 2010-11-09 | Hoya Corporation | Objective optical system and optical information recording/reproducing device having the same |
CN109218567A (en) * | 2017-06-30 | 2019-01-15 | 南昌欧菲光电技术有限公司 | Camera module and its photosensory assembly |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999057720A1 (en) * | 1998-05-07 | 1999-11-11 | Broome Barry G | Single objective lens for use with cd or dvd optical disks |
EP1022731A2 (en) * | 1999-01-22 | 2000-07-26 | Konica Corporation | Optical pickup apparatus and information recording/reproducing method |
-
2001
- 2001-11-08 KR KR1020027009034A patent/KR100834864B1/en not_active IP Right Cessation
- 2001-11-08 WO PCT/EP2001/013045 patent/WO2002041303A2/en active Application Filing
- 2001-11-08 JP JP2002543429A patent/JP4162996B2/en not_active Expired - Fee Related
- 2001-11-08 EP EP01996853A patent/EP1338008A2/en not_active Withdrawn
- 2001-11-08 US US10/169,926 patent/US6751021B2/en not_active Expired - Fee Related
- 2001-11-08 CN CNB018062776A patent/CN1206642C/en not_active Expired - Fee Related
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999057720A1 (en) * | 1998-05-07 | 1999-11-11 | Broome Barry G | Single objective lens for use with cd or dvd optical disks |
EP1022731A2 (en) * | 1999-01-22 | 2000-07-26 | Konica Corporation | Optical pickup apparatus and information recording/reproducing method |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1302938A2 (en) * | 2001-10-11 | 2003-04-16 | Konica Corporation | Optical pickup device and objective lens used in the same |
EP1302938A3 (en) * | 2001-10-11 | 2003-09-17 | Konica Corporation | Optical pickup device and objective lens used in the same |
US7508745B2 (en) | 2001-10-11 | 2009-03-24 | Konica Corporation | Optical element having a refractive function and an optical path difference providing function |
US7969854B2 (en) | 2001-10-11 | 2011-06-28 | Konica Corporation | Optical pickup device and objective lens used in the same |
EP1447798A2 (en) * | 2003-02-14 | 2004-08-18 | Konica Minolta Holdings, Inc. | Objective lens for optical pickup apparatus, optical pickup apparatus and optical information recording reproducing apparatus |
EP1447798A3 (en) * | 2003-02-14 | 2004-11-17 | Konica Minolta Holdings, Inc. | Objective lens for optical pickup apparatus, optical pickup apparatus and optical information recording reproducing apparatus |
CN100377227C (en) * | 2003-02-14 | 2008-03-26 | 柯尼卡美能达控股株式会社 | Objective lens for optical pickup device, optical pickup device, and optical information recording and reproducing device |
US7408866B2 (en) | 2003-02-14 | 2008-08-05 | Konica Minolta Holdings, Inc. | Objective lens for optical pickup apparatus, optical pickup apparatus and optical information recording reproducing apparatus |
WO2008065573A1 (en) * | 2006-11-27 | 2008-06-05 | Koninklijke Philips Electronics N.V. | Lens system for scanning device |
Also Published As
Publication number | Publication date |
---|---|
US6751021B2 (en) | 2004-06-15 |
JP4162996B2 (en) | 2008-10-08 |
CN1206642C (en) | 2005-06-15 |
US20030169498A1 (en) | 2003-09-11 |
JP2004514232A (en) | 2004-05-13 |
WO2002041303A3 (en) | 2002-09-06 |
KR100834864B1 (en) | 2008-06-03 |
CN1416568A (en) | 2003-05-07 |
EP1338008A2 (en) | 2003-08-27 |
KR20020071017A (en) | 2002-09-11 |
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