USO0RE40017E

(19) United States (12) Reissued Patent

(10) Patent Number:

Miyagawa et a].

(45) Date of Reissued Patent:

(54)

OPTICAL RECORDING/REPRODUCING APPARATUS FOR OPTICAL DISKS WITH VARIOUS DISK SUBSTRATE THICKNESSES

4,450,553 4,841,502 4,937,808 5,091,815

(75)

Inventors: Naoyasu Miyagawa, Suita (JP); Yasuhiro Gotoh Kadoma (JP)

5 991901 A 5,097,464 A

(73)

Ass1gnee: Matsushlta Electric Industr1alC0.,

’

.

US RE40,017 E

.

.

A A A A

5/1984 Holster et a1. 6/1989 Mlfmkami et a1 6/1990 shlmaFla er a1~ 2/1992 SuZukl

2/1992 Y*.1m*.‘m°F° et 31' 3/1992 N1s-h1uch1 et a1.

5,173,816 A

.

12/1992 Oglhara

5 208 801 A

’

Ltd" Osaka (JP)

Jan. 22, 2008

5/1993

’

5,255,262 A

Finegan

10/1993 Best et a1.

FOREIGN PATENT DOCUMENTS

(21) Appl. No.: 10/693,810 (22)

Filed:

Oct. 23, 2003 Related US. Patent Documents

Reissue of:

(64) Patent No.: Issued. .

0097250 A2

1/1984

144436 A1

6/1985

EP

0252445 A1

1/1988

EP EP

0327033 A2 452953 A2

8/1989 10/1991

5,235,581

Aug 10 1993 .

OTHER PUBLICATIONS

,

APPIZ NO‘:

07/740’629

Flled-

Aug-511991

Japanese Patent Abstract, “Optical Disc Regenerator”, vol. 2, N0. 32, Feb. 28, 1978, [Mitsubishi Denki K.K.(1)]; JPiAi52il53705.

U8. Applications: (63)

EP

EP

Braat, et al., “Principles of Optical Disc Systems,”3’d Edi

Continuation of application No. 09/460,223, ?led on Dec. 13, 1999, which is a continuation of application No. 08/396,

non’ 1987’ pp‘ 170E172 Van Nostrand’s Sclenn?c Encyclo Pedia, 3rd Edition, 1958, PP~ 1069*1070, 1149

981, ?led on Mar. 1, 1995, now Pat. No. Re. 36,445.

Primary ExamineriNabil Hindi

(30)

Forelgn Apphcatlon Prmnty Data

Aug. 9, 1990

(74) Attorney, Agent, or Firmistevens, Davis, Miller &

(JP) ......................................... .. 02-212537

Oct. 22, 1990

(JP) ......................................... .. 02-285006

Mar. 11, 1991

(JP) ......................................... .. 03-044798

Mosher, LLP (57)

(51) Int. C].

[An optical disc apparatus for recording, reproducing or

G11B 7/11 (52)

(200601)

erasing an information signal by converging a light ?ux onto a recording layer through a transparent substrate. The appa

US. Cl. ................. .. 369/5322; 369/94; 369/4437;

rams includes one Or a plurality Of Optical heads having 21

369/4412; 369/4423; 369/11224; 369/532 (58)

plurality of objective lenses Whose aberations have respec

Field of Classi?cation Search ............ .. 369/4423,

tivley been Corrected for a plurality Of disc Substrates Of

369/4412’ 4424’ 11201, 11202, 5322,

different thicknesses, a cartridge for enclosing the optical

369/532, 4437’ 94, 11224, 93, 120’ 4411’ 369/118’ 4434

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 signal. In accordance With the result of the discrimination as

See application ?le for complete search history. (56)

ABSTRACT

References Cited

to the thickness of the loaded optical disc, the objective lens, in 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

U'S' PATENT DOCUMENTS 4,037,929 A 7/1977 Bricot et a1.

I

57 56 ACTUATOR TRACKING omvmc00mm. CURRHQTSF. 4 CIRCUIT ll AND mCUSlNG—

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coN'l'Rals‘tslE (INIROLL. 515ml- FEQM

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38

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1 DRIVING CURRENT FROM LD DRMNG CIRCUIT 2o

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L_____________________l —-PHOTO DETECTm SIGNAL

US RE40,017 E Page 2

different substrate thicknesses. Instead of an optical head

distances, such as objective lenses or grating lenses, for

having objective lenses, an optical head having a Waveguide and a plurality of converging grating couplers Whose aber

performing aberration correction over a plurality of trans

rations have respectively been corrected for a plurality of

converging grating couplers Whose aberrations have respec tively been corrected for a plurality of disc substrates 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

substrate and an information layer by converging a light?ux on the information layer through the transparent substrate. The apparatus includes optical converging devices, with dijferent numerical apertures, focal distances or working

parent substrates of dijferent thicknesses of optical discs and a device for discriminating the type of optical disc based on the thicknesses of the transparent substrates. One of the optical converging devices that generates the least aberra tion is used according to a result ofthe discrimination ofthe thickness ofthe optical disk loaded in the apparatus to cause

the information signal to be suitably recorded, reproduced or erased onto/from the optical discs having the dijferent substrate thicknesses.

4 Claims, 18 Drawing Sheets

U.S. Patent

Jan. 22, 2008

Sheet 2 0f 18

FIG. 2

US RE40,017 E

U.S. Patent

Jan. 22, 2008

Sheet 3 0f 18

FIG.3A

FIG.3B

US RE40,017 E

U.S. Patent

Jan. 22, 2008

Sheet 4 0f 18

US RE40,017 E

F I G. 4A RECORDING LAYER

DISC SUBSTRATE

LOW NA LENS

FIG. 4B RECOR DING LAYER d2

'

4'"

m“

‘l‘lii‘iulé J

I

FD _

+ Y

wdLmsc SLBSTRATE

HIGH NA LENS

U.S. Patent

Jan. 22, 2008

Sheet 11 0f 18

2._985E“

US RE40,017 E

h2@0mg8 m_N1eu.ml5w

mO-P20oh.um_l?.m

_2E EB _

_

_

_

_

_

_

_

m2.5382m 85..mQBowd _w vb

U.S. Patent

Jan. 22, 2008

Sheet 16 0f 18

FIG. l6

MOVEMENT OF CONVERQD SPOT

EMITTED LIGHT

WAVEGUIDE LIGHT

OPTICAL WAVEGUIDE I

I

CONVERGING GRATING COLPLER

US RE40,017 E

U.S. Patent

Jan. 22, 2008

Sheet 17 0f 18

US RE40,017 E

FIG. I7

I ‘ l- '

I ‘l v ' n fs V0

TRACKING

ERROR SIGNAL

U.S. Patent

Jan. 22, 2008

Sheet 18 0f 18

FlG. |8A

0

US RE40,017 E

PRIOR ART

{ RECORDING LAYER

_________

LENS

FIG. ‘8B PRIOR ART

; RECORDING LAYER

N US'C

SUBSTRATE

LENS