US RE40,017 E1 | ||
Optical recording/reproducing apparatus for optical disks with various disk substrate thicknesses | ||
Naoyasu Miyagawa, Suita (Japan); and Yasuhiro Gotoh, Kadoma (Japan) | ||
Assigned to Matsushita Electric Industrial Co., Ltd., Osaka (Japan) | ||
Filed on Oct. 23, 2003, as Appl. No. 10/693,810. | ||
Application 07/740629 is a continuation of application No. 09/460223, filed on Dec. 13, 1999. | ||
Application 09/460223 is a continuation of application No. 08/396981, filed on Mar. 01, 1995, granted, now Re. 36445, filed on Dec. 14, 1999. | ||
Application 10/693810 is a reissue of application No. 07/740629, filed on Aug. 05, 1991, now 5,235,581, filed on Aug. 10, 1993. | ||
Claims priority of application No. 02-212537 (JP), filed on Aug. 09, 1990; application No. 02-285006 (JP), filed on Oct. 22, 1990; and application No. 03-044798 (JP), filed on Mar. 11, 1991. | ||
Int. Cl. G11B 7/11 (2006.01) |
U.S. Cl. 369—53.22 [369/94; 369/44.37; 369/44.12; 369/44.23; 369/112.24; 369/53.2] | 4 Claims |
[ 25. A signal processing circuit used for an optical disc apparatus which includes a light source driving circuit for controlling
a plurality of light sources and which records, reproduces or erases an information signal onto/from any one of N types (where N>2) of optical discs having transparent substrates of different thicknesses, each of said types of optical discs having at least
a said transparent substrate and an information layer, by converging a light beam emitted from one of the light sources according
to a control signal from the light source driving circuit onto the information layer through the transparent substrate, each
of said light sources corresponding to a respective one of said disc types, and by detecting a reflected light beam with an
optical detector, the signal processing circuit comprising: a discriminating signal generator, connected with the optical detector, for generating a disc discrimination signal indicating
the one of said types of optical discs; and
a controller for controlling the light source driving circuit to selectively activate one of the light sources according to
the disc discrimination signal.]
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