Pioneer Electronic Corporation

Pioneer Corporation

Bosch Automotive Systems Corporation

Norio Matsuda

Shinichi Naohara

Hitoshi Yamazaki

Alex Bradshaw

Kenichi Takahashi

Takashi Suzuki

Takeshi Sato

Yuichi Kimikawa

Kazushige Kawana

Hiroyuki Abe

Jun Togashi

Hideki Kinoshita

Akira Yasaki

Shigeru Kojima

Motoi Kimura

Yasuhiro Shinkai

Seiichi Ohsawa

Yasumitsu Wada

Hideaki Watarihana

Masakazu Takahashi

Morio Nozaki

Masaru Chijiiwa

Kazuya Kubota

Yoshitaka Ono

Tetsuya Kuwayama

An optical pickup device, which can effectively prevent occurrence of trouble in recording and reproducing of information due to the fact that an objective lens for each optical beam is contaminated while not adding unnecessary parts and while reducing a cost, is provided. An optical pickup device (P) which performs the recording or reproducing of information in or from an optical disc () by using an optical beam (B) or (D), comprises: objective lenses () and () on which cleaning films which are activated by radiation of the optical beam (B) and clean their surfaces are formed in an optical path, and a control unit () for setting an optical path of the optical beam (B) in such a way that the optical beam (B) reflected by the optical disc () is radiated on the objective lens ().

Optical pickup device

A disc transfer section for transferring an optical disc by guide members and a transfer roller is disposed adjacent to an opening of a casing. A detectorfor detecting the optical disc is disposed adjacent to the opening. When unloading the optical disc, the peripheral edge of the optical disc contacts with slide members so that the slide members are slid, thereby sensor switches SWto SWare appropriately switched on and off. Based on a time difference between the timings of the on/off switchings, the relation between a movement trajectory of the center of the optical disc and an axis of symmetry that is a straight line indicating a transfer direction at the center of the opening is judged in order to control the drive of a transfer motor according to the movement trajectory. The amount of advancement when the unloading is completed is kept constant.

Transfer control device, transfer control method, transfer unit and disc unit

Provided is a disk carrying mechanism, in which a guide member () is installed on a disk guide block () and the disk guide block () with the guide member () being disposed on an opposite side of a roller () with a carrying route therebetween. The guide member () is formed as a ridge extending in a direction orthogonal to a direction of a carrying route and inclined from a center part to a peripheral edge part of a disk so that its height can be increased.

Disk carrying mechanism and disk player

In a method for driving a solenoid proportional control valve () used for flow rate control of a common rail system pump adapted to regulate flow rate by regulating the duty ratio of a pulse voltage applied to a solenoid coil (F) of a solenoid (E), when an operating condition liable to cause hysteresis in the operation of the solenoid proportional control valve () is present, the peak value or pulse width of the pulse voltage is temporarily increased to instantaneously boost the driving force of the solenoid (E), thereby ensuring smooth operation of a piston (C) and stabilizing the flow rate control.

Method and apparatus for driving a solenoid proportional control valve utilized for flow rate control

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

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 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 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

Disclosed is a focus control apparatus of the present invention capable of successfully performing an accurate focus jump operation without an erroneous operation of a focus actuator. The apparatus irradiates a light beam onto a recording medium, and generates a focus actuator drive signal for moving an optimized light convergence point of the light beam from one recording surface to the other, based on a focus error signal generated based on a returned light from the recording medium. The focus control apparatus comprises a detector for detecting that the focus error signal crosses a predetermined level as a specified level crossing; instruction means for generating a focus jump instruction; a drive signal generating means for generating the drive signal in response to the focus jump instruction and receiving a detection output from the detection circuit to recognize a timing of a specified level crossing of the focus error signal upon receipt of the detection output, thereby extinguishing the drive signal at the timing of the specified level crossing detection timing; and inhibiting means for inhibiting the recognition of the specified level crossing by the drive signal generating section for a predetermined period in response to the focus jump instruction.

Focus control apparatus

An electronic equipment has a stick as a movable input device provided to be manually moved. The position of the stick is detected. In accordance with the detected position, the movement of the stick is restricted within a predetermined movable range so as to be moved a plurality of predetermined areas. The area in which the stick is located is detected. In accordance with the detected area, corresponding control data stored in a memory are read out, and the electronic equipment is controlled by the read out control data.

Signal input system for an electronic equipment

A driving apparatus allows simple detection of the light writing characteristic of light writing means, such as a CRT, without detaching the light writing means from the liquid crystal light valve. A display apparatus uses such a photoconductive liquid crystal light valve. The driving apparatus applies a drive voltage signal from a drive voltage source across two electrodes of a photoconductive liquid crystal light valve having a liquid crystal layer, a photoconductive layer and the two electrodes arranged to sandwich the liquid crystal layer and photoconductive layer and allows a writing light to be incident upon the photoconductive layer by light writing means coupled to a writing side, and comprises detection means for detecting an impedance across the two electrodes. The apparatus generates an adjusting video signal having white and black levels, supplies the adjusting video signal as an input video signal to video signal amplifying means, and compares the levels of detection outputs of writing light intensity detection means at times of generation of the adjusting video signals of the white level and the black level, with reference levels corresponding to the white and black levels. The offset and gain of the video signal amplifying means are changed in accordance with the comparison outputs of the comparing means.

Apparatus for driving photoconductive liquid crystal light valve having

A photoconductive type liquid crystal valve maintains good gradation contrast characteristics in a projection image irrespective of if and when a possible temperature change occurs. The photoconductive type liquid crystal light valve comprises a laminated body including a liquid crystal layer 15, a photoconductive layer 15, and a light shielding layer 17, and a pair of driving electrodes which sandwich the laminated body and form an image forming area. A pair of temperature detecting electrodes are provided at positions out of the image forming area to sandwich at least the light shielding layer and detect a change in impedance of the light shielding layer, thereby detecting a temperature change of the light valve. By changing the level of a driving voltage signal which is supplied to the driving electrode on the basis of the detected temperature change, the gradation characteristics and contrast can be held constant from the time point of the initial setting of the black level even when the temperature fluctuates.

Growing community of inventors

Kawagoe, Japan

Norio Matsuda