Abstract: When halting reproduction of an optical disc, the work memory stores identification information of the optical disc and halt position information thereof, and a contents data memory section stores information of reproduction contents. When resuming reproduction, a disc ID recognition section recognizes the identification information of the optical disc, and reads out the halt position information from the work memory, and reproduction operation is carried out from a halt position with the use of the reproduction content stored in the contents data memory section. During this, an initial process of the disc recording/reproducing section is carried out. Thereafter, reproduction from the optical disc starts uninterruptedly. This allows next reproduction of the information storage medium to start from the halt position at which the reproduction is halted.

Abstract: A signal evaluation device for evaluating a decoded signal of maximum likelihood decoding includes: a differential metric circuit for finding differential metrics; comparators for judging whether a difference of differential metrics exceeds a predetermined threshold; counters for counting respective output pulses of the comparators; and a controller for finding the probability of the differential metrics falling at or below the predetermined threshold, based on the number of measured samples and the number of samples counted by the counters, and processing the probability by arithmetic operations so as to obtain an index of signal evaluation. With this arrangement, signal evaluation devices for evaluating a recording medium or a recording medium driving device can have a simpler structure and can perform evaluations in a plurality of PR modes.

Abstract: When halting reproduction of an optical disc, the work memory stores identification information of the optical disc and halt position information thereof, and a contents data memory section stores information of reproduction contents. When resuming reproduction, a disc ID recognition section recognizes the identification information of the optical disc, and reads out the halt position information from the work memory, and reproduction operation is carried out from a halt position with the use of the reproduction content stored in the contents data memory section. During this, an initial process of the disc recording/reproducing section is carried out. Thereafter, reproduction from the optical disc starts uninterruptedly. This allows next reproduction of the information storage medium to start from the halt position at which the reproduction is halted.

Abstract: A signal evaluation device for evaluating a decoded signal of maximum likelihood decoding includes: a differential metric circuit for finding differential metrics; comparators for judging whether a difference of differential metrics exceeds a predetermined threshold; counters for counting respective output pulses of the comparators; and a controller for finding the probability of the differential metrics falling at or below the predetermined threshold, based on the number of measured samples and the number of samples counted by the counters, and processing the probability by arithmetic operations so as to obtain an index of signal evaluation. With this arrangement, signal evaluation devices for evaluating a recording medium or a recording medium driving device can have a simpler structure and can perform evaluations in a plurality of PR modes.