WO1998049680A1 - Support d'enregistrement et dispositif de lecture optique - Google Patents
Support d'enregistrement et dispositif de lecture optique Download PDFInfo
- Publication number
- WO1998049680A1 WO1998049680A1 PCT/JP1998/001894 JP9801894W WO9849680A1 WO 1998049680 A1 WO1998049680 A1 WO 1998049680A1 JP 9801894 W JP9801894 W JP 9801894W WO 9849680 A1 WO9849680 A1 WO 9849680A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- wavelength
- density
- objective lens
- laser
- numerical aperture
- 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
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/2407—Tracks or pits; Shape, structure or physical properties thereof
-
- 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
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/2407—Tracks or pits; Shape, structure or physical properties thereof
- G11B7/24085—Pits
-
- 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
- G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
- G11B7/2407—Tracks or pits; Shape, structure or physical properties thereof
- G11B7/24073—Tracks
- G11B7/24079—Width or depth
-
- 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
Definitions
- the present invention relates to a recording medium and an optical pickup device, and more particularly, to a recording medium having a recording density about twice that of a compact disk and an optical pickup device for reproducing information from the recording medium.
- Optical discs with a thickness of about 1.2 mm such as CD-ROMs (Compact Disc-Read Only Memory), that can read information using a semiconductor laser are provided.
- CD-ROMs Compact Disc-Read Only Memory
- focus servo control and tracking servo control are performed on an objective lens in an optical pickup device, and a pit array on a signal recording surface is irradiated with a laser beam.
- the recording density has been increasing to record long moving images.
- the DVD Digital Video Disc
- the DVD Digital Video Disc
- the thickness of the DVD is 0.6 mm, and by bonding these on both sides, 9.4 Gbytes of information can be recorded on one optical disc.
- double-density CDs having the same diameter and thickness as CDs and having twice the recording density of CDs, and CD- ⁇ having three times the recording density of CDs are currently being developed.
- LDs laser discs
- MUSE-LDs that record muse signals are also available.
- the double-density CD will have a diameter and thickness of C
- the various optical disks currently provided various values are employed for the wavelength of the semiconductor laser in the optical pickup device, the numerical aperture of the objective lens, the track pitch of the recording medium, the shortest pit length, and the like.
- the reproduction characteristics of the double-density CD can be improved by setting the specific values of the wavelength of the semiconductor laser, the numerical aperture of the objective lens, the track pitch, and the minimum pit length. Whether it can be optimized has not yet been considered.
- an object of the present invention is to provide a recording medium having excellent reproduction characteristics and an optical pickup device therefor. Disclosure of the invention
- a recording medium for an optical pickup device having a laser having a wavelength of ⁇ m and an objective lens having a numerical aperture of NA has the following formula: 0.7 / TP / (E / NA ) Provide a track with a pitch of TP ⁇ m that satisfies ⁇ 0.8.
- an optical pickup device for a recording medium including a track having a pitch of TP / zm includes a laser and an objective lens.
- the laser has a wavelength of ⁇ / m.
- the objective lens focuses the beam from the laser and has a numerical aperture of N A that satisfies the equation: 0.7 TPZ (ZN A) ⁇ 0.8.
- the laser wavelength ⁇ ⁇ , the numerical aperture of the objective lens ⁇ , and the track pitch ⁇ ⁇ ⁇ m have the above relationship, crosstalk and jitter are suppressed, and a sufficient tracking error signal can be obtained. The reproduction characteristics are improved.
- a recording medium for an optical pickup device including a laser having a wavelength of ⁇ ⁇ m and an objective lens having a numerical aperture of ⁇ has a formula: 0 ⁇ 40 ⁇ L / (e / NA) ⁇ 0.45
- the track with the shortest pit length of L ⁇ m is provided.
- an optical pickup device for a recording medium including a track having a shortest pit length of L // m includes a laser and an objective lens.
- the laser has a wavelength of
- the objective lens focuses the beam from the laser and has the formula: 0.40 L / ( ⁇ ZNA) has NA numerical aperture satisfying 0.45.
- the track pitch ⁇ ⁇ ⁇ satisfies the relationship 0.7 TP / ( ⁇ () ⁇ 0.8, or the shortest pit length L ⁇ m is 0.40 LZ (2 / NA) ⁇ 0. Since it is only necessary to satisfy the relationship of 45, various semiconductor lasers and objective lenses can be used, and as a result, the design of the optical pickup device becomes easy.
- FIG. 1 is a diagram showing a configuration of an optical pickup device according to an embodiment of the present invention.
- FIG. 2 is a plan view showing a configuration of the optical disc according to the embodiment of the present invention.
- FIG. 3 is a graph showing a relationship between crosstalk and T PZ ( ⁇ / ⁇ ⁇ ) in the first embodiment of the present invention.
- FIG. 4 is a graph showing a relationship between a normalized tracking error signal and TP / ( ⁇ / ⁇ ) according to the first embodiment of the present invention.
- FIG. 5 is a graph showing the relationship between ⁇ and ⁇ in the first embodiment of the present invention.
- FIG. 6 is a graph showing the relationship between the modulation factor and L / ( ⁇ / ⁇ ) according to the second embodiment of the present invention.
- FIG. 7 is a graph showing the relationship between the jitter and the degree of modulation in the second embodiment of the present invention.
- FIG. 8 is a graph showing the relationship between L (shortest pit length) and fly / ⁇ .
- an optical pickup device 10 is for reproducing a signal from a double-density CD 5 having a recording density twice as high as that of a CD.
- the semiconductor laser 1 generates a laser beam having a wavelength of ⁇ ⁇ m.
- the collimator lens 2 makes the laser beam from the semiconductor laser 1 parallel.
- the half mirror 13 transmits the laser beam from the collimator lens 2 straight, and reflects the laser beam reflected by the double density CD 5 toward the photodetector 7 vertically.
- the objective lens 4 has a numerical aperture of NA, and focuses the laser beam transmitted through the half mirror 3 on a signal recording surface 55 of double density CD 5.
- the focusing lens 6 focuses the laser beam reflected by the half mirror 3 on the photodetector 7.
- the photodetector 7 detects the laser beam from the focusing lens 6, and generates a reproduction signal, a focus error signal, a tracking error signal, and the like in response to the detection.
- the laser beam generated by the semiconductor laser 1 is collimated by the collimator lens 2, and then enters the objective lens 4 through the half mirror 3. .
- the laser beam incident on the objective lens 4 is condensed by the objective lens 4 and is irradiated on the signal recording surface 55 through a transparent substrate 56 having a double density CD 5.
- the laser beam After being reflected by the signal recording surface 55, the laser beam returns to the half mirror 3 through the objective lens 4, and half of the laser beam is reflected in a direction at 90 degrees to the incident direction.
- the light is focused on the photodetector 7 by the focusing lens 6.
- the photodetector 7 detects the intensity of the laser beam reflected from the signal recording surface 55, and generates a reproduction signal, a focus error signal, a tracking error signal, and the like according to the intensity.
- the double-density CD 5 has a circular transparent substrate 56 formed of a polycarbonate resin or the like. On the main surface of the transparent substrate 56, a large number of pits 57 are formed in a spiral shape. A row of these pits 57 forms a track 58. Therefore, here, one track 58 runs spirally. The spacing between adjacent tracks 58 is called the track pitch.
- This Rack 58 has a track pitch of TP / m.
- the original recording signal is modulated by the EFM method, and the pit 57 has various lengths since the pit 57 is formed according to the modulated signal.
- the 3-bit pit 59 is the shortest of the pits 57.
- the length of such a pit 59 is called the shortest pit length.
- track 58 has a shortest pit length of Lm.
- the track pitch TP and the shortest pit length L are determined so that the recording density is twice the CD, and the track pitch TP and the shortest pit length L are determined based on the determined track pitch TP and shortest pit length L.
- the wavelength of the semiconductor laser 1 and the numerical aperture of the objective lens 4 suitable for reproducing the double-density CD 5 are determined.
- Table 1 below shows the wavelength ⁇ ( ⁇ ) of the semiconductor laser 1 used in the first embodiment, the numerical aperture ⁇ of the objective lens 4, ⁇ , the track pitch ⁇ ⁇ , and ⁇ ⁇ ( ⁇ / ⁇ ). .
- Table 1 shows not only the above-mentioned parameters used for reproducing double-density CD5, but also for comparison, the parameters used for reproducing CD, LD, MUSE-LD, CD-ct, and DVD. One is also shown.
- CD playback uses a semiconductor laser with a wavelength of 0.780 // m (780 nm) and an objective lens with a numerical aperture of 0.45, and the track pitch TP is set to 1.6 / zm.
- ⁇ / ⁇ is 1.73
- TP / ( ⁇ / ⁇ ) is 0.925.
- the track pitch of a CD is For example, it is shown in Table 1 of “Electronic Technology”, Nikkan Kogyo Shimbun, 1996, Vol. 38, No. 8, p.
- a semiconductor laser having a wavelength of 0.780 m and an objective lens having a numerical aperture of 0.50 are used, and the track pitch TP is set to 1.6 ⁇ . Is done. In this case, ⁇ is 1.56 and ⁇ ⁇ ( ⁇ / ⁇ ) is 1.026.
- a semiconductor laser having a wavelength of 0.670 or 0.685 ⁇ m and an objective lens having a numerical aperture of 0.55 are used, and the track pitch TP Is set to 1.1 m.
- the wavelength of the semiconductor laser is 0.67 O ⁇ m
- lZNA is 1.218
- TPZ (ZNA) is 0.90.
- the wavelength of the semiconductor laser is 0.685 / im
- ⁇ / ⁇ is 1.245
- T P / ( ⁇ / ⁇ ) is 0.88.
- a semiconductor laser having a wavelength of 0.685 or 0.680 ⁇ m and an objective lens having a numerical aperture of 0.55 are used. Set to 1.0 / zm.
- f / NA is 1.245
- TP / ( ⁇ / ⁇ ) is 0.80.
- Wavelength of semiconductor laser one The case of 0. 6 70 ⁇ ⁇ , ⁇ / / NA is l. 2 1 8 next, ⁇ V / ( ⁇ / ⁇ ) becomes 0.8 2.
- a semiconductor laser having a wavelength of 0.635 or 0.650 ⁇ m and an objective lens having a numerical aperture of 0.60 are used, and the track pitch TP Is set to 0.74 / m.
- the wavelength of the semiconductor laser is 0.635 ⁇ m, ⁇ , ⁇ is 1.058, and T P / ( ⁇ / ⁇ ) is 0.6992.
- the wavelength of the semiconductor laser is 0.650 / xm, ⁇ is 1.083, and T P / ( ⁇ / ⁇ ) is 0.683.
- the track pitch of DVDs is also shown in Table 1 of the "Electronic Technology" mentioned above.
- the semiconductor laser 1 having a wavelength of 0.780 ⁇ m (780 nm), and 0.5 2
- the objective lens 4 having a numerical aperture of 1 is used, and the track pitch TP of the double-density CD 5 is set to 1.
- f / NA is 1.50
- TP / ( ⁇ / NA) is 0.73.
- the recording density in the track running direction should be twice that of the CD
- the recording density in the cross direction of the track should be less than that of the CD.
- a method of doubling is conceivable.
- Figure 3 shows the relationship between crosstalk and TPZ (ZNA) measured using a semiconductor laser 1 with a wavelength of 0.780 ⁇ m and an objective lens 4 with a numerical aperture of 0.52.
- Crosstalk indicates the rate at which signals from adjacent tracks are mixed into regular signals, and decreases as the value of TPZ ( ⁇ / ⁇ ) increases. If the crosstalk value exceeds 80%, the jitter will increase and an appropriate reproduced signal cannot be obtained. Therefore, it is desirable that 0.7 ⁇ ( ⁇ / ⁇ ).
- Fig. 4 shows the relationship between the tracking error signal standardized on the basis of CD and TP / ( ⁇ / ⁇ ).
- the tracking error signal is a well-known control signal generated by the photodetector 7 for tracking servo control, and the standardized tracking error signal is obtained from a CD having a track pitch of 1.6 ⁇ . It shows the magnitude of the tracking error signal obtained from this double-density CD 5 when the magnitude of the tracking error signal is "1". If the relationship of 0.7 ⁇ ⁇ ⁇ ( ⁇ , 30 ⁇ ) 0.8 is satisfied, the normalized tracking error signal falls within the range of 30 to 50% and is obtained from the double-density CD. By amplifying the tracking error signal about twice, tracking servo control can be performed without being affected by noise. Therefore, such double-density CD 5 can easily ensure compatibility with CD.
- the double-density CD 5 has a track pitch of TP // m that satisfies the equation: 0.7 ⁇ TT / (e / NA) ⁇ 0.8 , Crosstalk and jitter are suppressed, and the reproduction characteristics are improved.
- TP // m that satisfies the equation: 0.7 ⁇ TT / (e / NA) ⁇ 0.8 , Crosstalk and jitter are suppressed, and the reproduction characteristics are improved.
- compatibility with a CD can be easily secured.
- the track pitch TP is mainly set to a desired value, but in the second embodiment, the shortest pit length is set to a desired value instead of the track pitch TP.
- Table 2 below shows the wavelength of the semiconductor laser used for reproducing the double-density CD 5, the numerical aperture ⁇ of the objective lens 4, ⁇ / ⁇ , the shortest pit length L, and LZ ( ⁇ / ⁇ ). .
- Table 2 shows not only the parameters described above for double-density CD5, but also the parameters for CD, LD, MUSE-LD, and DVD for comparison.
- a semiconductor laser having a wavelength of 0.780 // m and an objective lens having a numerical aperture of 0.45 are used for CD reproduction, and the shortest pit length L is Set to 0.833 ⁇ m.
- ⁇ / ⁇ is 1.73
- L / ( ⁇ / ⁇ ) is 0.481.
- Electric Technology indicates a minimum pit length of 0.834 ⁇ m for CDs.
- a semiconductor laser having a wavelength of 0.780 ⁇ m and an objective lens having a numerical aperture of 0.50 are used, and the shortest pit length L is set to 0.543 jum.
- ⁇ / ⁇ is 1.56
- L / ( ⁇ / ⁇ ) is 0.348.
- a semiconductor laser having a wavelength of 0.670 ⁇ m and an objective lens having a numerical aperture of 0.55 are used, and the shortest pit length is 0.486 / im.
- a semiconductor laser having a wavelength of 0.635 or 0.650 / X m and an objective lens having a numerical aperture of 0.60 are used, and the shortest pit length L is 0.4. Set to ⁇ m.
- ⁇ is 1.058 and LZ ( ⁇ ) is 0.378.
- LZ ((/ ⁇ ) is 0.369.
- the “electronic technology” mentioned above indicates that the minimum bit length of a DVD is 0.400 ⁇ m.
- a semiconductor laser 1 having a wavelength of 0.780 / m (780 nm) and an objective lens 4 having a numerical aperture of 0.52 are used.
- the shortest pit length L is set to 0.618 ⁇ m. In this case, ⁇ / ⁇ is 1.50, and L, ( ⁇ / ⁇ ) is 0.421.
- the shortest pit length L of the double density CD 5 is examined based on the average value of 1.3 mZ seconds.
- FIG. 6 shows the relationship between the modulation degree of the double density CD 5 and LZ ( ⁇ / ⁇ ).
- the degree of modulation is the ratio of the signal intensity of the shortest pit length (3 ⁇ ) to the signal intensity of the longest pit length (11 T).
- the modulation factor is in the range of 40 to 50%.
- Fig. 7 shows the relationship between the jitter and the modulation factor of the 3 ⁇ signal.
- the 3 ⁇ jitter is about 25 nanoseconds.
- the error rate will be practically acceptable.
- the modulation depth that can be actually used is 40% or less. Desirably, it is also within a large range.
- L / (e / NA) is 0.45, it is desirable that L / (e / NA) ⁇ 0.45.
- FIG. 8 The condition of 0.40 ⁇ L / ( ⁇ / ⁇ ) and 0.45 described above is shown in FIG.
- the shortest pit length L, the semiconductor laser The wavelength of 1 and the numerical aperture NA of the objective lens 4 are set to desired values in the region 80 excluding the straight lines 81 and 82. Therefore, the reproduction characteristics of the double-density CD 5 are improved.
- the double-density CD 5 has the shortest pit length of L ⁇ m satisfying the following equation: 0.40 ⁇ L / ( ⁇ / ⁇ ) ⁇ 0.45
- the reproduction characteristics are improved, for example, jitter is suppressed.
- the track pitch TP is set to a desired value
- the shortest pit length L is set to a desired value
- Both the track pitch TP and the shortest pit length L are set to desired values.
- the track pitch TP ⁇ m of the double density CD 5 is The formula: 0.7 TP / (E / NA) satisfies 0.8, and the shortest pit length L / zm satisfies the formula: 0.40 ⁇ L / (; L / NA) ⁇ 0.45.
- the aperture of the objective lens 4 is The number NA satisfies the formula: 0.7 to TPZ ( ⁇ / ⁇ ) ⁇ 0.8, and the formula: 0.40 to LZ ( ⁇ / ⁇ ) ⁇ 0.45.
- the double-density CD 5 is expressed by the following equation: 0.7 ⁇ T
- the recording medium of the present invention is useful not only as an optical disk for karaoke and games, but also as an optical disk for movies and audio.
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- Optical Head (AREA)
- Optical Record Carriers And Manufacture Thereof (AREA)
- Optical Recording Or Reproduction (AREA)
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE69830990T DE69830990T2 (de) | 1997-04-25 | 1998-04-23 | Optische vorrichtung |
EP98917668A EP0978830B1 (en) | 1997-04-25 | 1998-04-23 | Optical system |
US09/403,370 US6262966B1 (en) | 1997-04-25 | 1998-04-23 | Recording medium and optical pickup device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9/109432 | 1997-04-25 | ||
JP9109432A JPH10302320A (ja) | 1997-04-25 | 1997-04-25 | 記録媒体および光ピックアップ装置 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998049680A1 true WO1998049680A1 (fr) | 1998-11-05 |
Family
ID=14510107
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1998/001894 WO1998049680A1 (fr) | 1997-04-25 | 1998-04-23 | Support d'enregistrement et dispositif de lecture optique |
Country Status (8)
Country | Link |
---|---|
US (1) | US6262966B1 (ja) |
EP (1) | EP0978830B1 (ja) |
JP (1) | JPH10302320A (ja) |
KR (1) | KR20010020231A (ja) |
CN (1) | CN1252884A (ja) |
DE (1) | DE69830990T2 (ja) |
TW (1) | TW391000B (ja) |
WO (1) | WO1998049680A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0942414A1 (en) * | 1998-03-12 | 1999-09-15 | Nec Corporation | Optical disk apparatus |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT247679Y1 (it) | 1999-11-29 | 2002-09-09 | Atop Innovation Spa | Perfezionato disco ottico compatto, o cd. |
JP4287580B2 (ja) * | 1999-11-30 | 2009-07-01 | Tdk株式会社 | 光情報媒体の再生方法 |
JP2001229576A (ja) * | 2000-02-10 | 2001-08-24 | Sony Corp | 光記録媒体及び光記録媒体製造用原盤 |
JP2001229546A (ja) | 2000-02-14 | 2001-08-24 | Sony Corp | 光記録媒体及び光記録媒体製造用原盤 |
TWI239002B (en) * | 2000-03-10 | 2005-09-01 | Sony Corp | Optical recording/reproducing apparatus, optical head apparatus, optical disc drive apparatus, tracking control method for use therein, and optical disc |
EP1342234A1 (en) * | 2000-12-15 | 2003-09-10 | Atop Innovation SPA | Improved optical compact disc, or cd |
JP2003173543A (ja) * | 2001-09-26 | 2003-06-20 | Victor Co Of Japan Ltd | 情報記録担体及び情報記録担体の再生方法及び情報記録担体の再生装置 |
KR20030030506A (ko) * | 2001-10-11 | 2003-04-18 | 삼성전자주식회사 | 고밀도 광디스크 |
KR100896681B1 (ko) * | 2001-12-18 | 2009-05-14 | 삼성전자주식회사 | 컴팩트 디스크에 데이터를 기록하는 방법 및 그 장치 |
JP3967691B2 (ja) * | 2003-03-31 | 2007-08-29 | 株式会社東芝 | 情報記憶媒体と情報再生装置と情報記録再生装置 |
JP2007501991A (ja) * | 2003-05-21 | 2007-02-01 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | 光ディスクに情報を記憶する/光ディスクから情報を取り出す方法 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0887747A (ja) * | 1994-02-02 | 1996-04-02 | Sanyo Electric Co Ltd | ディスク及びディスク再生方法 |
JPH09147421A (ja) * | 1995-11-17 | 1997-06-06 | Toray Ind Inc | 光ディスク用基板および光記録媒体 |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
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JP3002318B2 (ja) | 1992-01-20 | 2000-01-24 | パイオニア株式会社 | 光ディスク及び光ディスク再生装置 |
JPH0689473A (ja) * | 1992-09-10 | 1994-03-29 | Matsushita Electric Ind Co Ltd | 光磁気記録媒体 |
US5477527A (en) * | 1994-02-02 | 1995-12-19 | Sanyo Electric Co., Ltd. | High density optical disc and optical disc player |
JPH0887770A (ja) * | 1994-03-18 | 1996-04-02 | Sanyo Electric Co Ltd | 光学式情報再生装置及び方法 |
JP3268126B2 (ja) * | 1994-07-06 | 2002-03-25 | シャープ株式会社 | 光記録媒体 |
JPH08180492A (ja) * | 1994-12-26 | 1996-07-12 | Sharp Corp | 光ピックアップ |
JP3210549B2 (ja) * | 1995-05-17 | 2001-09-17 | 日本コロムビア株式会社 | 光情報記録媒体 |
EP0886267A4 (en) * | 1996-03-06 | 1999-11-03 | Toshiba Kk | FOCUSING DEVICE AND PROVIDED OPTICAL DEVICE |
-
1997
- 1997-04-25 JP JP9109432A patent/JPH10302320A/ja active Pending
- 1997-10-30 TW TW086116133A patent/TW391000B/zh not_active IP Right Cessation
-
1998
- 1998-04-23 WO PCT/JP1998/001894 patent/WO1998049680A1/ja active IP Right Grant
- 1998-04-23 KR KR1019997009821A patent/KR20010020231A/ko not_active Application Discontinuation
- 1998-04-23 CN CN98804414A patent/CN1252884A/zh active Pending
- 1998-04-23 EP EP98917668A patent/EP0978830B1/en not_active Expired - Lifetime
- 1998-04-23 DE DE69830990T patent/DE69830990T2/de not_active Expired - Fee Related
- 1998-04-23 US US09/403,370 patent/US6262966B1/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0887747A (ja) * | 1994-02-02 | 1996-04-02 | Sanyo Electric Co Ltd | ディスク及びディスク再生方法 |
JPH09147421A (ja) * | 1995-11-17 | 1997-06-06 | Toray Ind Inc | 光ディスク用基板および光記録媒体 |
Non-Patent Citations (1)
Title |
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See also references of EP0978830A4 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0942414A1 (en) * | 1998-03-12 | 1999-09-15 | Nec Corporation | Optical disk apparatus |
US6266302B1 (en) | 1998-03-12 | 2001-07-24 | Nec Corporation | Optical disk apparatus |
Also Published As
Publication number | Publication date |
---|---|
DE69830990D1 (de) | 2005-09-01 |
US6262966B1 (en) | 2001-07-17 |
JPH10302320A (ja) | 1998-11-13 |
EP0978830A4 (en) | 2000-07-26 |
TW391000B (en) | 2000-05-21 |
KR20010020231A (ko) | 2001-03-15 |
CN1252884A (zh) | 2000-05-10 |
EP0978830A1 (en) | 2000-02-09 |
EP0978830B1 (en) | 2005-07-27 |
DE69830990T2 (de) | 2006-05-24 |
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