Kabushiki Kaisha Toshiba

Masayuki Tamura

Hironori Nakajo

You Yoshioka

Yasuhiro Hayashi

Satoru Maeda

Multi-drive optical disk apparatus and a method and a label for easily confirming the respective performance characteristics for the different kinds of optical disks are provided. The respective performances, such as a data transfer rate are indicated by multiple-fold speed forms, respectively. The performance indication label is affixed on one surface of the optical disk drive. The performance indication label is constructed by arranging an indication for a data reading performance from a CD-ROM disk and a DVD-ROM disk, an indication for a data writing performance to a CD-RW disk, a DVD-RAM disk, a DVD-RW disk, a DVD-R disk, and a CD-R disk, and an indication for a data writing and reading performances to and from a DVD-RAM disk in a hypothetical circle.

Disk apparatus for driving different kinds of optical disks and a method for identifying performance characteristics for a particular optical disk installed in the disk apparatus

Function indicating label

A focus servo control system is a system for selectively applying a light beam to a disk on which data is recorded on plurally layered recording surfaces and setting the focus position of the light beam on a selected recording surface of the two-layered recording surfaces based on a signal read from reflected light from the selected recording surface of the plurally layered recording surfaces of the disk and includes a focus error detector for detecting a positional difference between the focus position of the light beam and the selected recording surface of the plurally layered recording surfaces, a sample-hold circuit for sampling and holding an output of the focus error detector, a focus position correcting circuit for correcting the focus position of the light beam based on one of the output of the focus error detector and an output of the sample-hold circuit, a data signal level detector for detecting the signal level relating to data read out from the disk, a comparator for comparing a signal level detected by the data signal level detector with a predetermined level to output the result of comparison, and a selector for selecting one of the output of the focus error detector and the output of the sample-hold circuit as an input signal of the focus position correcting circuit based on the output of the comparator.

Focus servo control system and disk reproducing system

In making a layer jump or focus search on a multilayer optical disk having two or more signal recorded layers, an objective lens is moved in a focusing direction to focus a laser beam onto a desired signal recorded layer with focus servo kept OFF. Based on the number of times a focus error signal having an S-shaped characteristic obtained as a result of driving the objective lens exceeds a predetermined voltage level, arrival at the desired signal recorded layer is determined. In this state, the focus servo is made active at the time when the focus error signal first goes to the 0 level.

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Kanagawa-ken, Japan

Masayuki Tamura