USO0RE40908E
(19) United States (12) Reissued Patent
(10) Patent Number:
Miyagawa et a]. (54)
(45) Date of Reissued Patent:
OPTICAL RECORDING/REPRODUCING APPARATUS FOR OPTICAL DISKS WITH VARIOUS DISK SUBSTRATE THICKNESS
JPTAT52T153705'
Yasuhiro Gotoh, Kadoma JP
_
(57)
Related US‘ Patent Documents
(63)
ratus includes one or a plurality of optical heads having a
plurality of objective lenses Whose aberrations have respec tively been corrected for a plurality of disc substrates of 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
51235581
Aug. 10, 1993 07/740,629 Aug, 5, 1991 _
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
NOV‘ 22’ 1999
. . U'S' APP119m1°¥1S1
_
Primary ExamineriNabrl Z Hrndl (74) Attorney, Agent, or FirmiDickinson & Wright, PLLC
(21) Appl. No.: 09/609,829
Relssue 0T3 (64) Patent NO? Issued: Appl. No.: Filed;
(Continued) _
( ) (73) AssigneeZ Panasonic Corporation, Osaka (JP)
_ Flled:
Sep. 8, 2009
OTHER PUBLICATIONS Japanese Patent Abstract, “Optical Disc Regenerator”, vol. 2, N0. 32, Feb. 28, 1978, [Mitsubishi Denki K.K.(1)];
(75) Inventors: Naoyasu Miyagawa, Suita (JP);
(22)
US RE40,908 E
discrimination hole and for generating a discrimination sig nal. In accordance With the result of the discrimination as to
_
Contlnuatlon OTaPPTTCaTTOn N°~ 08/396,981, ?led on Man 1’
the thickness of the loaded optical disc, the objective lens, in
1995 ’ now Pat‘ NO‘ Re‘ 36’445 '
Which the occurrence of the aberration is smallest, is used, so
(30)
Foreign Application Priority Data
that the information signal can preferably be recorded, reproduced or erased onto/from the optical discs having dif
Aug. 9,
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
ferent
Oct 22, 1990
(JP)
Mar. 11, 1991
(JP) ........................................... .. 3-044798
(51)
2'285006
Int- CTG11B 7/00
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
(2006-01) _
same object] An optical recording/reproducing apparatus
(52)
US. Cl. ............................. .. 369/4412, 36'9/11224, 369/4423’ 369/532
_
for recording] reproducing Or erasing an information Signal onto/from an optical disc having at least a transparent sub
(58)
Field Of Classi?cation Search ............. .. 369/4412,
Slrale and on information layer by converging a light?ux 011
369/4424, 44.23, 112.24, 53.2, 44-11, 93, 369/94, 95, 44.37; 250/2015, 227.11 See application ?le for complete search history,
the information layer through the transparent substrate. The apparatus includes optical converging devices, with di?'erent numerical apertures, focal distances or working distances, such as objective lenses or grating lenses, for performing
(56)
References Cited
aberration correction over a plurality of transparent sub
U-S- PATENT DOCUMENTS
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
4’037’929 A
7/1977 Bncot et 31'
verging devices that generates the least aberration is used
(Continued)
according to a result ofthe discrimination ofthe thickness of
FOREIGN PATENT DOCUMENTS
the optical disc 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 EP
0097250 A2
l/l984
[kl-61mm“
(Continued)
ACTUATOR DRIVING
CURRENTS FROM TRACKING CONTROL CIRCUIT II AND FDCUSING CONTROL CIRCUIT I3
14 Claims, 18 Drawing Sheets
I"
ORIVING CURRENT FROM
21TH
SELECTOR 2|
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48
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US RE40,908 E Page 2
US. PATENT DOCUMENTS 4,450,553 4,841,502 4,937,808 5,091,815 5,091,901 5,097,464 5,173,816
A A A A A A A
5/1984 6/1989 6/1990 2/1992 2/1992 3/1992 12/1992
Holster et 31. Murakami et a1. Shimada et a1. Suzuki Yamamoto et a1. Nishiuchi et a1. Osihara
5,208,801 A
5/1993 Finegan
5,255,262 A
10/1993 Best et 31.
FOREIGN PATENT DOCUMENTS EP EP EP EP
144436 0252445 0327033 452953
A1 A1 A2 A3
6/1985 1/1988 8/1989 10/1991
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Sheet 2 0f 18
FIG. 2
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FIG.3B
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AMENDED
FIG.4A RECORDING WE;
{Ty FL \lDOISC suesmr: _
1 {Low NA LENS
AMENDED
FIG.4B
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OF5Z.MS0EmGU Emm_EUNJwm
mZJOk
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ZJOC
2w.0hC3m_D>%QmE
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FIG.I6 WVEVBIT OF CONVEFKED SPOT
EMITTED LIGHT
WAVEGUIDE LIGHT
OPTICAL
V
,
wAvscsuos ,
j .3 J‘
as“ mmsou =R --?Z
9,
/1V @s 7""1‘9'” 4 CONVERGING GRATING COLPLER
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FIG l?
ZOwLrJUOZw-
V0
TRACKING ERROR SIGNAL
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FIG. |8A PRIOR ART
0
, RECORDING LAYER
__-____-_
I __J-__
DISC SUBSTRATE
LENS
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PRlOR ART
,RECORDING LAYER / _
_
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N USC
SUBSTRATE
LENS