Pioneer Corporation

Pioneer Electronic Corporation

Hideaki Watarihana

Kazunori Matsuo

Yoshimichi Nishio

Masakazu Takahashi

Hiroki Goto

Hiroyuki Kobayashi

Hidetsugu Kubota

Yasutaka Suzuki

Teruo Takahashi

Takuya Abe

Kiyoshi Furukawa

Takeshi Sato

Hiroyuki Abe

Alex Bradshaw

Kenichi Takahashi

Kazushige Kawana

Takashi Suzuki

Shinichi Naohara

Hitoshi Yamazaki

Yuichi Kimikawa

Motoi Kimura

Susumu Yoshida

Tomomichi Kimura

Norio Matsuda

Yoshihiro Hashizuka

An information recording medium reproducing system has an insertion opening, a recording medium storing portion and a medium carrying device. Photodetectors are provided for detecting passing of the recording medium and for producing a passing signal when the medium passes. A controller is provided for controlling operation of the medium carrying device. The controller applies a discharge signal to the medium carrying device when the passing signal is not produced within a predetermined time, whereby the medium carrying device is actuated in discharge operation.

Information reproducing system having means for preventing a breakdown thereof caused by abnormal conditions

An optical disk playing apparatus which performs at least a focusing servo operation for reading light as a servo operation and irradiates the reading light onto one optical disk, receives reflected light from the optical disk by a pickup to obtains a light receiving signal, moves an irradiated position of the reading light onto the optical disk to cross tracks on the disk; generates a tracking error signal in response to the reading signal during the track crossing; compares the tracking error signal with a threshold value; and determines the type of the optical disk in accordance with the number of pulses in the compared result signal within a predetermined period from start of the track crossing.

Optical disk playing apparatus and method for discriminating optical disk

System for reproducing information recorded on an information recording medium

An apparatus for detecting the absence or the presence of the occurrence of the abnormal insertion that a plurality of disc bodies each of which should be inserted separately one by one are inserted consecutively, provided with: a passing detecting device for detecting the passing of the disc body, mounted on the passing route of the disc body, and a determining device for determining the occurrence of the abnormal insertion if the detecting device detects the passing again after the detecting device detected the passing once.

Apparatus and method for detecting abnormal insertion of disc body

A first detector is provided for detecting an optical disc inserted in an opening of a reproducing system and for producing a first signal, and a second detector is provided on a reproducing device for detecting the disc carried to the device and for producing a second signal. A sensing circuit is provided for sensing a temporary reduction of a voltage of power supplied to the system and for producing a temporary reduction signal. A control means is provided to be responsive to the first signal and to the temporary reduction signal for operating a carrying device to carry the disc in an unloading direction, and in a loading direction when the disc reaches a predetermined position.

System for reproducing recording mediums

A disc reproducing apparatus is provided which is adapted to scan information tracks to read information recorded on an information recording medium. This disc reproducing apparatus comprises: determining means capable of determining an actually happened track jump, said determining being effected when a difference between a present reproducing positional information and a reference reproducing positional information is larger than a predetermined value; detecting means for detecting a present track position which is just being reproduced at a present time; and setting means for setting said predetermined value corresponding to the present track position, in accordance with a result of the detecting means.

Disc reproducing apparatus for determining a track jump

A system for reproducing recording mediums has a reproducing device, a storing device for storing a plurality of recording mediums, a moving device for relatively moving the reproducing device and storing device for reproducing a recording medium. A controller is provided to be responsive to a command for operating the moving device for positioning the reproducing device and the storing device at predetermined fixable initializing positions.

Initializing position for transporting a reproducing apparatus

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 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.

A carriage controller for a multi-layer disc which is capable of performing a stable carriage control during reproduction of a multi-layer disc of the opposite recording scheme. A tracking error signal is relayed by an equalizer, and a carriage motor is driven in accordance with an output signal of the equalizer. An information reading direction on a layer of a disc on which a pickup reads information is detected, and an equalizer characteristic is set in the equalizer in accordance with the detection result.

Carriage controller for multi-layer disc

Apparatus and method for focus control are devised to cope with a fluctuation of an optimum gain of a focus servo loop due to a difference between light reflectance of recording surfaces or the like and to allow an optimum focal position of read light to preferably trace a target recording surface. The focus control apparatus of the invention includes: reading device for generating a read signal of a recording medium 1; a focus servo loop for allowing an optimum converging position of the read light to trace the target recording surface in accordance with a focus error signal FE by using a focusing actuator to displace the optimum converging position of the read light in the optical axial direction; a level detecting unit of the read signal; a level detecting unit of an error signal FE; amplifiers and of a read signal RF and the error signal FE; and a control unit for driving the actuator so as to allow the optimum converging position of the read light to approach the recording surface in the set-up mode and for controlling gains of the amplifiers so that a detection level by the detecting unit in the set-up mode reaches a predetermined level and a detection level by a detecting unit reaches a predetermined level.

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Saitama-ken, Japan

Hideaki Watarihana