Pioneer Electronic Corporation

Pioneer Corporation

Shinichi Naohara

Ryuichi Naito

Hiroyuki Hirano

Norio Matsuda

Katsumi Ishii

Kanya Matsumoto

Hiroshi Yokota

Kazunori Matsuo

Yoshifumi Tsukada

Alex Bradshaw

Takashi Sasaki

Takeshi Sato

Masao Yoshida

Yasuhisa Okamoto

Hitoshi Yamazaki

Hiroyuki Abe

Kenichi Takahashi

Yuichi Kimikawa

Kazushige Kawana

Motoi Kimura

Takashi Suzuki

Tomomichi Kimura

Hideaki Watarihana

Yasutaka Suzuki

Kenji Nakamura

Yasuhiro Shinkai

Kenji Uchiyama

Masakazu Takahashi

Shigeru Kojima

Morio Nozaki

Yoshifumi Tsukuda

An error correction apparatus includes: an error correction circuitfor performing a data error correction based on a first error correction algorithm selected from among a plurality of error correction algorithms having different correction strengths; an error determination unitfor using the first error correction algorithm to detect that the data error correction has been disabled; and a computerfor selecting a second error correction algorithm from the plurality of error correction algorithms, and for controlling the error correction circuitto use the second error correction algorithm to perform the error correction for data for which it has been determined that the first error correction algorithm is not capable of correcting errors in the data.

Error correction method, apparatus and program product

An information reproducing apparatus improved is provided with: an optical pickup () for reading record information recorded on an optical disc () and outputting a read signal; an error correction circuit () for executing an error correction process with respect to the outputted read signal and outputting output data through the error correction process corresponding to the record information; and a buffering memory device () for buffering the outputted output data. The apparatus is further provided with a microcomputer () for altering the error correction process in the error correction circuit depending on a memory status of the buffering memory device, if in the error correcting device, an error is detected in the read signal or an error ratio of the error becomes greater than a predetermined threshold value.

Information reproducing apparatus and method, and error correction system

A record medium playback apparatus includes a playback section and a playback control section. The playback control section is adapted to control a playback start position of the program information when the record medium playback apparatus is restarted after power thereof was turned off. The playback control section determines the playback start position of the program information using a first sequence when the record time of the whole program information corresponding to the playback position at the power off is less than a predetermined time. The playback control section determines the playback start position of the program information using a second sequence when the record time of the whole program information corresponding to the playback position at the power off is equal to or longer than the predetermined time.

Optical reproducing system having resume function based on recording time of each program on the medium

An information reproducing apparatus is provided with: a clamping device () capable of clamping and clamp-releasing a recording medium (); a rotating device () for rotating the recording medium clamped by the clamping device; a reading device () disposed opposite to an information record surface of the recording medium for reading information recorded on the information record surface of the recording medium; a driving device (D,) capable of moving the reading device in a radial direction of the recording medium; and a linkage device () for linking a clamping or clamp-releasing action by the clamping device with a movement of the reading device by the driving device. The driving device moves the reading device as a first driving voltage is supplied to the driving device upon reading the information recorded on the information record surface, the first driving voltage including such a value that the action of the clamping device is not linked with the movement of the reading device by the linkage device.

Information reproducing apparatus and method, and drive control system

Two sum output signals from two sets of the photodetector elements located symmetrically each other with respect to a light-receiving center of the photodetector of the optical pickup are amplified individually by two amplifiers. A focus error signal is generated in accordance with a difference between respective output levels of the two amplified signals. The gains of the two amplifiers are adjusted in accordance with the focus error signal. A predetermined bias voltage is applied to the focus error signal line in the focus servo control means in accordance with the focus error signal.

Focus servo controller with collision avoidance and method therefor

Partial information such as the beginning data of each of chapters is read from a CD and written in a HDD at a higher speed than that in a normal reproduction while the normal reproduction is carried out using a buffer memory . After the chapters relative to all CDs have been written in the HDD , reproduction is carried out in switching between the information remaining in the HDD and the information included in the CD. This configuration makes it unnecessary to record the information beforehand, and permits an unreproduciable blank in reproduction to be filled with audio information during track search or CD change while the reproduction is carried out normally.

Recording/reproducing apparatus

A tilt servo apparatus which can correct a tilt error at a high speed and with high precision irrespective of a magnitude of the tilt error even if a response speed of a liquid crystal device decreases is provided. An amount of change and an increase/decrease of a signal intensity are detected by changing a correction value of a tilt error correcting arrangement by a first correction width, and a correction width of the correction value and a correcting direction are determined on the basis of the detection result. When the amount of change of the signal intensity is smaller than a predetermined amount of change, the correction width is changed to a second correction width which is smaller than a first correction width. When it is larger than the predetermined amount of change, the correction width is changed to a third correction width larger than the first correction width. The correction width is also determined in accordance with a change in environmental temperature.

Tilt servo apparatus and control method thereof

A tilt servo apparatus of an optical disc recording/reproducing apparatus, which includes sampling portion for sampling an RF envelope signal at every predetermined rotational angle on the basis of a rotation signal being synchronous with a rotation of the optical recording medium, calculating portion for calculating an average value of the sampled envelope intensities, and control portion for controlling a tilt error correction. The control portion determines the amount of the tilt error correction on the basis of the average value.

Liquid crystal tilt servo apparatus

A reproducing apparatus and method for continuously reproducing data including a memory configured to store at least heading portions of respective data groups from one or more data groups recorded on a recording medium; a reproducing device configured to read at least the heading portions of one or more of the data groups from the recording medium; and a controller configured to control the memory and the reproducing device, and configured to execute a cross-fading operation, in which a portion of at least one of the data groups being reproduced from the memory are cross-faded with a portion of at least one of the data groups being reproduced from the recording medium by the reproducing device.

Reproducing device with cross-fading operation

A tilt servo control apparatus has a tilt error correcting device for correcting a tilt error caused by a tilt angle defined between a normal at an irradiating position of a laser beam irradiated onto a recording surface of an optical recording medium and an optical axis of the laser beam. The tilt error correcting device is driven based on an intensity of the reflected light of the laser beam irradiated onto the recording surface. The apparatus provides a control to hold a drive value of the tilt error correcting device to a predetermined value in response to a track jump command for changing the irradiating position of the laser beam from the first irradiating position to the second irradiating position that is away therefrom by a distance corresponding to a predetermined number of tracks.

Tilt servo apparatus for optical disc recording/playing apparatus

A disc player has a first array of pickup devices arranged in a line for reading information from a disc and a second array of pickup devices arranged in a parallel line. The pickup devices are each independently movable along their respective lines with the devices of the first line offset from the devices of the second line so as to form a zigzag pattern.

Disc player with objective lens arranged in a zigzag pattern

A focusing control apparatus is designed to perform a focus jumping operation successfully. The apparatus has reading device which irradiates read light to a recording medium,having information recording surfaces formed on at least two layers, respectively, receiving return light of the read light from the recording medium, and generating a read signal; and control device which executes a focus jumping process to generate a drive signal of a focusing actuator to move an optimum light converging position of the read light from one of the recording surfaces to the other based on a focusing error signal that is generated based on the return light. The apparatus further has drop-out detecting device which detects a drop-out of the read signal and vibration detecting device which detects a vibration of the recording medium or reading device. The control device executes the focus jumping process only when the drop-out is not detected and a vibration detection level of the vibration detecting means is lower than a predetermined value.

Focusing control apparatus for optimally directing light onto a recording surface

A focus control apparatus for a multilayer optical recording medium performs an adequate focus jump on a multilayer optical recording medium. Threshold values are set according to the amount of a level change in a focus error signal of a loaded multilayer optical recording medium, and focus jump control is conducted based on the result of comparison between the level of the focus error signal and the set threshold values. Positive and negative threshold values to be compared with the level of the focus error signal to detect a zero-crossing point of the focus error signal are set in accordance with the amount of a level change in the focus error signal, after which an acceleration operation of the focus actuator is started in response to a focus jump instruction to shift the focus position of read light for a focus jump, the acceleration operation is stopped in accordance with zero-crossing detection, a deceleration operation of the focus actuator is started thereafter and is stopped in accordance with zero-crossing detection, so that the operation returns to the focus servo operation.

Focus control apparatus for multilayer optical recording medium

A focus jump control apparatus of a player for playing a multilayer recording disc surely achieves a focus jump. This apparatus includes: a focusing servo loop for allowing a focal point to trace a recording surface in accordance with a focusing error signal by using a focusing actuator to displace the focal point of read light to a disc in the optical axial direction; and a tracking servo loop for allowing the focal point to trace disc tracks. A loop opening/closing control unit opens/closes focusing/tracking servo loops in response to an instruction and closes the focusing servo loop when the movement of the focal point from one of the recording surfaces to the other. During the movement of the read light focal point, the closing state of the tracking servo loop is maintained. Jump driving means generates a drive signal of the actuator to move the focal point from one of the recording surfaces to the other based on the error signal under the opening/closing control of the focusing/tracking servo loops.

Focus jump control apparatus of a player for multilayer recording disc

A focus control apparatus for a multilayer optical recording medium which performs an appropriate focus jump on a multilayer optical recording medium. This focus control apparatus implements such focus jump control as to temporarily release a focus servo on one layer of a loaded multilayer optical recording medium, shift the focus position of read light on another target layer and then restart the focus servo on the another target layer, detects an ambient temperature, sets a drive signal condition according to the temperature detection output, and moves the focus position of the read light under the set drive signal condition. Specifically, this apparatus generates an acceleration signal to start moving the focus position of read light and a deceleration signal to decelerate movement of the focus position of the read light, as drive signals for a focus actuator in order to execute a focus jump operation, detects an ambient temperature of the focus actuator, and sets signal conditions for the acceleration signal and the deceleration signal according to the detected temperature.

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Saitama, Japan

Shinichi Naohara