USO0RE41918E
(19) United States (12) Reissued Patent
(10) Patent Number: US RE41,918 E (45) Date of Reissued Patent: *Nov. 9, 2010
Miyagawa et a]. (54)
OPTICAL RECORDING/REPRODUCING
(56)
References Cited
APPARATUS FOR OPTICAL DISKS WITH VARIOUS DISK SUBSTRATE THICKNESSES
U.S. PATENT DOCUMENTS 4,037,929 4,450,553 4,841,502 4,937,808 5,091,815 5,091,901 5,097,464 5,173,816
(75) Inventors: Naoyasu MiyagaWa, Suita (JP); Yasuhiro Gotoh, Kadoma (JP)
(73) Assignee: Panasonic Corporation, Osaka (JP) (*) (21) (22)
Notice:
This patent is subject to a terminal dis claimer.
Appl. No .:
09/460,223
Filed:
Dec. 13, 1999
Issued:
Appl. No.: Filed:
Bricot et al. Holster et a1. Murakami et al. Shimada et al. Suzuki Yamamoto et al. Nishiuchi et al. Osihara
5,208,801 A
5/1993 Finegan
5,255,262 A
10/1993 Best et a1.
EP EP EP EP EP EP EP
Reissue of:
Patent No.:
7/1977 5/1984 6/1989 6/1990 2/1992 2/1992 3/1992 12/1992
FOREIGN PATENT DOCUMENTS
Related US. Patent Documents
(64)
A A A A A A A A
5,235,581 Aug. 10, 1993 07/740,629 Aug. 5, 1991
0097250 144436 0252445 0252445 0327033 0327033 452953
A2 A1 A1
1/1984 6/1985 1/1988 1/1988 8/1989 8/1989 10/1991
A2 A2
OTHER PUBLICATIONS
US. Applications: (63)
Continuation of application No. 08/396,981, ?led on Mar. 1, 1995, now Pat. No. Re. 36,445.
(30)
JPiAi52il53705.
Foreign Application Priority Data
Aug. 9, 1990
(JP) ......................................... .. 02-212537
Oct. 22, 1990 Mar. 11, 1991
(JP) ......................................... .. 02-285006 (JP) ......................................... .. 03-044798
(51)
(52) (58)
Int. Cl. G09B 19/017 G09B 23/033 G09B 23/088 G09B 7/005 G09B 7/042
Japanese Patent Abstract, “Optical Disc Regenerator”, vol. 2, No. 32, Feb. 28, 1978, [Mitsubishi Denki K.K.(1)]; Braat, et al., “Principles of Optical Disc Systems,” 3rd Edi tion, 1987, pp. 1704172 Van Nostrand’s Scienti?c Encyclo pedia, 3rd Edition, 1958, pp. 106941070, 1149. Primary ExamineriNahil Zhinkdi (74) Attorney, Agent, or FirmiDickinison Wright PLLC
(2006.01) (2006.01) (2006.01) (2006.01) (2006.01)
(57)
ABSTRACT
[An optical disc apparatus for recording, reproducing or erasing an information signal by converging a light ?ux onto a recording layer through a transparent substrate. The appa
US. Cl. ............................. .. 369/44.12; 369/112.24;
ratus includes one or a plurality of optical heads having a
369/53.2; 369/44.23
plurality of objective lenses Whose aberrations have respec tively been corrected for a plurality of disc substrates of
Field of Classi?cation Search ........... .. 369/112.24,
369/112.1, 112.02, 53.2, 44.37, 44.23, 44.24, 369/93, 94, 95, 109, 109.02, 53.22, 112.01, 369/44.11, 44.12, 112, 118, 58, 120; 250/2015 See application ?le for complete search history.
different thicknesses, a cartridge for enclosing the optical disc, a discrimination hole Which is formed on the cartridge, and a sensor for detecting the opening/closing state of the discrimination hole and for generating a discrimination sig
39
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TRACKING CONTROL . cmcun H AND FOCUSING CONTROL CIRCUIT I3
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US RE41,918 E Page 2
nal. In accordance With the result of the discrimination as to
apparatus includes optical converging devices, with di?'erent
the thickness of the loaded optical disc, the objective lens, in
numerical apertures, focal distances or working distances, such as objective lenses or grating lenses, for performing
Which the occurrence of the aberration is smallest, is used, so
that the information signal can preferably be recorded, reproduced or erased onto/ from the optical discs having dif ferent substrate thicknesses. Instead of an optical head hav
ing objective lenses, an optical head having a Waveguide and a plurality of converging grating couplers Whose aberrations have respectively been corrected for a plurality of disc sub strates of different thicknesses is provided to achieve the
same object. ] An optical recording/reproducing apparatus for recording, reproducing or erasing an information signal onto/from an optical disc having at least a transparent sub strate and an information layer by converging a light?ux on
the information layer through the transparent substrate. The
aberration correction over a plurality of transparent sub
strates of di?erent thicknesses of optical discs and a device for discriminating the type ofoptical disc based on the thick nesses of the transparent substrates. One of the optical con verging devices that generates the least aberration is used according to a result ofthe discrimination ofthe thickness of the optical disk loaded in the apparatus to cause the infor mation signal to be suitably recorded, reproduced or erased
onto/from the optical discs having the di?'erent substrate thicknesses.
9 Claims, 18 Drawing Sheets
US. Patent
Nov. 9, 2010
Sheet 2 0f 18
FIG. 2
US RE41,918 E
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Nov. 9, 2010
Sheet 3 0f 18
FIG.3A
FIG.3B
US RE41,918 E
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Sheet 4 0f 18
US RE41,918 E
AMENDED
FIG.4A RECORDING LAYER _ __=__.___=____:
5
ml.‘
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E {LOW N11 LENS
AMENDED
FIG.4B RECORDING LAYER
d2 #11:
76
4
Fa»...~\i_... »~*D use SUBSTRATE ,1‘ L wee-r N2. LENS
US. Patent
Nov. 9, 2010
Sheet 7 0f 18
US RE41,918 E
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US. Patent
Nov. 9, 2010
Sheet 12 0f 18
0.2P5ZwFE.DQ 1m_Neo.w-5Um . 1I.|2.9385.68
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US RE41,918 E
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Sheet 16 0f 18
US RE41,918 E
FIG. l6
WT OF CCNVERGED SPOT
EMH'TED LIGHT
I I
OPTICAL
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WAVEGUIDE LIGHT
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I CONVERGING GRATING COLPLER
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SAW mmsoucsn
WAVE
US. Patent
Nov. 9, 2010
Sheet 17 0f 18
FIG. I?
zoWm?b5ul20Ew4o mpc5.o1>0<3
_-I|. "I'l
l'nI-
TRACKING ERROR SIGNAL
US RE41,918 E
US. Patent
Nov. 9, 2010
Sheet 18 0f 18
US RE41,918 E
F'G. IBA PRIOR ART
{RECORDING LAYER DISC SUBSTRATE
LENS
FIG. IBB PRlOR ART
~ use
SUBSTRATE
LENS
