Matsushita Graphic Communication Systems, Inc.

Keiji Ueki

Motoyasu Ohno

Atsushi Shinno

Eizo Katayama

Chiaki Ohigashi

Tatsuya Katano

Hiraku Yamamoto

Tsukasa Kanazawa

Shinji Hasunuma

Kazuo Suzuki

Hitoshi Kato

Kaname Sawada

A method for managing a defect in an optical disk employed in a recording/reproducing apparatus. The optical disk includes a data area and a preliminary area. Further, the data area includes sectors for storing data and the preliminary area includes alternate sectors for defective sectors occurring after initialization of the optical disk. In the optical disk, physical addresses are assigned to all of the sectors of the data area and the preliminary area in an ascending order. In contrast, logical addresses are assigned to the sectors in an ascending order skipping the defective sectors detected at the time of the initialization and the sectors of the preliminary area. The method for managing a defect in an optical disk comprises the steps of constructing a table in which a cumulative number of defective sectors detected at the time of the initialization of the optical disk and being present between a starting physical address of the optical disk and a sector subsequent to a defective sector is used as the logical address of the sector subsequent to the defective sector and of converting the logical address of a sector into the physical address thereof by using the table. Thereby even when a defective sector occurs in the optical disk, the logical address of a sector can easily be converted into the physical address thereof.

Method for managing a defect in an optical disk by assigning logical

A color image recording apparatus comprises edge detection device with image sensors for detecting longitudinal edges of electrostatic recording paper, and mark detection device for detecting registration marks formed at an equal pitch along the edges of the recording paper. Both edges are detected at a first pass thereof through the edge detection device, and the detected output is stored in a memory. During each of second and subsequent passes, detected data is compared with the initially stored data to correct for expansion and shrinkage of the recording paper. Oblique motion of the recording paper is detected from the timing difference between registration marks formed on opposite sides of the recording paper, which timing difference is used to change line recording timing. A single correction is periodically repeated and changed until completion of the correcting for oblique motion of the recording paper as well as expansion or shrinkage thereof, hence ensuring an exact positional coincidence of the individual color images.

Apparatus for forming a color image

A storage medium provided with a read/write storage region, another read-only storage region and a preliminary storage region for storing data to be stored in defective portions, which are defective in a storing function, of the read/write storage region and the read-only storage region. Thereby, defective portions can suitably be effected even when a read/write storage region and a read-only storage region coexist in a storage medium.

Storage medium having read/write storage region and read-only storage

An optical disc is subdivided into a plurality of concentric tracks. The tracks are further subdivided into a plurality of sectors. A method for recording data on such an optical disc includes the steps of designating some of the sectors as preliminary sectors and the remaining sectors as user sectors, identifying defective user sectors, and recording data corresponding to the defective sectors on the preliminary sectors.

Method for recording data on non-defective sectors of an optical disk

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Zama, Japan

Keiji Ueki