US RE40,958 E1
Medium, apparatus, and method related to encryption resultant information
Mitsuaki Oshima, Kyoto (Japan)
Assigned to Panasonic Corporation, Osaka (Japan)
Filed on Dec. 16, 2005, as Appl. No. 11/304,674.
Application 10/611926 is a division of application No. 11/272484, filed on Nov. 14, 2005.
Application 09/796534 is a division of application No. 09/305318, filed on May 05, 1999, granted, now 6,243,330.
Application 09/305318 is a division of application No. 08/970162, filed on Nov. 13, 1997, granted, now 5,959,948.
Application 08/534771 is a division of application No. 08/281337, filed on Jul. 27, 1994, granted, now 5,473,584.
Application 11/272484 is a continuation of application No. 09/796534, filed on Mar. 02, 2001, granted, now 6,674,703.
Application 08/970162 is a continuation of application No. 08/534771, filed on Sep. 27, 1995, granted, now 5,699,331.
Application 08/281337 is a continuation in part of application No. 08/184117, filed on Jan. 21, 1994, granted, now 5,526,328.
Application 08/184117 is a continuation in part of application No. 08/009709, filed on Jan. 27, 1993, granted, now 5,682,360.
Application 11/304674 is a reissue of application No. 10/611926, filed on Jul. 03, 2003, now 6,859,427, filed on Feb. 22, 2005.
Claims priority of application No. 4-13809 (JP), filed on Jan. 29, 1992; application No. 4-42558 (JP), filed on Feb. 28, 1992; application No. 4-50328 (JP), filed on Mar. 09, 1992; application No. 4-68031 (JP), filed on Mar. 26, 1992; application No. 4-111176 (JP), filed on Apr. 30, 1992; application No. 4-194450 (JP), filed on Jul. 22, 1992; application No. 4-280874 (JP), filed on Sep. 25, 1992; application No. 5-8596 (JP), filed on Jan. 21, 1993; application No. 5-92219 (JP), filed on Mar. 25, 1993; application No. 5-107423 (JP), filed on Apr. 09, 1993; application No. 5-205682 (JP), filed on Jul. 27, 1993; application No. 5-297504 (JP), filed on Nov. 02, 1993; application No. 5-314114 (JP), filed on Nov. 19, 1993; application No. 6-104879 (JP), filed on Apr. 18, 1994; and application No. 6-156089 (JP), filed on Jul. 07, 1994.
This patent is subject to a terminal disclaimer.
Int. Cl. G11B 7/00 (2006.01)
U.S. Cl. 369—53.11  [369/47.12; 369/53.21; 380/228; 705/57] 1 Claim
OG exemplary drawing
 
[ 12. A reproducing method for reproducing video signals recorded in a recording layer of an optical disk in such a manner that tracking variations are formed at an address position in a circular or spiral track comprising:
disk driving step of rotating an optical disk;
an optical head operating step for emitting a light beam and receiving light from said optical disk to read information recorded in said disk in the form of pits;
tracking controlling step of effecting tracking control so that a light spot on said recording layer of said optical disk resulted from said light beam follows a series of pits on a track of said optical disk;
a tracking amount detection step of detecting from a tracking amount sensor an amount of the tracking variation in the address position;
a disk checking step of properly judging whether the current disk is legal or illegal according to the distribution of tracking variations, comparing the amount of the tracking variation with a tolerance value, wherein said tolerance value is set so that the current disk is judged to be legal if the amount of the tracking variation is within the tolerance and to be illegal if the amount of the tracking variation is outside the tolerance;
reproducing step responsive to an output signal at said optical head operating step for reproducing a video signal; and
an output/operation stopping step of stopping outputting of video information reproduced at said reproducing step to be externally outputted or stopping said reproducing step in accordance with said disk checking step.]