Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Akihiko Nishioka

Mitsuaki Oshima

Teruyuki Takizawa

Mitsuro Moriya

Takashi Yumiba

Koichi Morioka

Shinichi Konishi

Yuuichi Kuze

Masatoshi Yajima

Katsuya Watanabe

Masayoshi Nakamura

Tetsuya Shihara

Yasuo Nakata

Tomio Yamamoto

Yuu Okada

Masahiro Inagaki

Asayuki Matsumura

Koujiro Okamoto

An optical disc device includes: an optical pickup including a first laser light source that emits laser light, an objective lens that focuses the laser light emitted from the first laser light source onto an optical disc, and a light receiving element that receives reflected light from the optical disc, and performs photoelectric conversion on the reflected light received to output a received-light signal; an FS signal generator that generates an FS signal indicating the light amount of the reflected light from the optical disc, based on the received-light signal from the light receiving element; and a dirt determiner that determines that dirt is present in the optical pickup, when the peak level of the FS signal is less than a dirt determination threshold, and controls the light receiving element to increase the peak level of the received-light signal from the light receiving element.

Optical disc device and recording and reproduction device

An optical disc drive device includes a spindle motor that rotates an optical disc, an OPU, a first controller that causes the spindle motor and the OPU to read recorded data from the rotating optical disc, and an transmitter that transmits the read recorded data to a signal processing device disposed external to the optical disc drive device. The recorded data transmitted by transmitter is stored in a buffer provided in the signal processing device. The first controller decreases the rotational speed of the optical disc based on free space information indicating the free space of the buffer.

Optical disc drive device and playback device

An optical disc device of the present invention comprises an insertion detection optical sensor which detects insertion of an optical disc based on light emitted from a first light emitting element to a first light receiving element being blocked, and an ejection detection optical sensor provided on the downstream side in the carry-in direction to the insertion detection optical sensor to detect ejection of the optical disc based on light emitted from a second light emitting element to a second light receiving element being blocked. The optical disc device is structured such that, in a state that the optical disc is attached onto the turntable, when the light of the first light emitting element is blocked and the light of the second light emitting element is not blocked, the optical disc device recognizes that a lens cleaner is attached onto the turntable as the optical disc, and the optical disc device performs a cleaning operation.

Optical disc device and lens cleaner

A tracking apparatus for an optical information reproduction apparatus includes the following: a photoelectric detector () in which a far-field pattern of a light spot converged on a recording medium is formed across a divided light-receiving cell; an arithmetic unit () for outputting at least a pair of arithmetic signals from the output of the photoelectric detector (); a phase comparator () for detecting a phase difference between the output signals of the arithmetic unit (); an absolute value detector () for detecting an absolute value of the output signal of the phase comparator (); a level detector () for generating a signal that indicates whether or not a convergence position of the light spot is located off an information track by detecting a predetermined number of times or more the output signal of the absolute value detector () has become larger than a predetermined value; a sensitivity detector () for detecting and outputting the sensitivity of the level detector () by observing the output signal of the level detector (); and a controller () for adjusting the detection conditions of the level detector () so that the output of the sensitivity detector () is a predetermined value.

Tracking apparatus for optical information reproduction apparatus

An optical disk is provided for recording data of a signal modulated according to a predetermined modulation method in a form of concavo-convex pits. The optical disk includes a first area having a reflecting film partly removed, and a second area for recording pits which are different from pits satisfying requirements of the predetermined modulation method. The first area having the reflecting film partly removed includes a portion which is formed by removing the reflecting film, and has a length longer than a maximum pit length determined by the modulation method in a circumferential direction of the optical disk. When the pits recorded on the optical disk are physically copied as they are, physical copying of the optical disk can be prevented by utilizing such a difference that the authorized optical disk differs from a pirated copy in a combination of the respective reproduced signals of the first and second areas.

Optical disk, and method and apparatus for reproducing information recorded in optical disk

An optical disk apparatus includes a converging section for converging a light beam toward an information carrier; a moving section for moving the light beam converged by the converging section in a direction perpendicular to a surface of the information carrier; a light detector for detecting the light beam reflected by the information carrier; a convergence state detecting section for generating a convergence state signal representing a convergence state of the light beam at a convergence point on the information carrier and outputting a reproduction signal from the information carrier, based on the output from the light detector; a focus controller for driving the moving section to make the convergence state constant based on the convergence state signal and a prescribed target position; a reproduction quality signal detector for detecting a reproduction quality signal representing a quality of the reproduction signal based on the reproduction signal; a reproduction quality signal measuring section for changing the target position and measuring a value of the reproduction quality signal corresponding to each of the changed target positions; a reproduction quality signal characteristic determining section for determining a characteristic of the reproduction quality signal based on the value of the reproduction quality signal corresponding to each of the changed target positions; and a target position searching section for searching for an optimum target position of the focus controller for optimizing the value of the reproduction quality signal based on a determination result of the reproduction quality signal characteristic determining section.

Optical disk drive apparatus capable of searching an optimum target position

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Osaka, Japan

Akihiko Nishioka