Sony Corporation

Masaru Tezuka

Satoru Tobita

Noriaki Nishi

Naoki Inoue

Shigeaki Koike

Koji Ishiwata

Kunika Hashimoto

Yoichiro Sako

Shinji Kaneko

Hiroyuki Yamauchi

Teruaki Higashihara

Yoshizo Mihara

Mitsuru Hanajima

Roger Lagadec

Teruhito Noshiro

Yasushi Matsumoto

Keisuke Sekiguchi

Kazuyuki Hishida

Hiroyuki Hara, Deceased

An optical disk drive () for optically recording and/or reproducing information signals is provided in which the power of a light beam emitted from an optical head () to an optical disk () is controlled by an optical-coupling efficiency varying elements () correspondingly to the type of the optical disk, recording layer in a multilayer optical disk and a mode of operation selected while a variation of the optical-coupling efficiency is being detected by a light-detecting element (), thereby positively varying the optical-coupling efficiency in a minimum necessary time. Thus, the power of the light beam focused on the optical disk can be varied in a wide range without having to extremely raise the ratio in output power between modes of operation at a light source (). Therefore, even a light source whose rating of optical output power is small can be used to write and read information signals to and from any of optical disks of different types or to each of recording layers in a multilayer optical disk with a high accuracy. Namely, good characteristics in writing and reading information signals can be assured without having to largely vary the ratio in output power of the light source from the write to read mode, from one to another type of optical disks or from one to another recording layer of the multilayer optical disk.

Optical head, optical recording medium recording and/or reproducing apparatus and recording and/or reproducing method using the optical head

The present invention provides an optical disc camcorder unit having a base plate assembly loaded with an optical disc and a camcorder main body accommodating the base plate assembly, the base plate assembly is swingably set to the camcorder main body via a rotating shaft so that the base plate assembly rotates in an axial direction about the rotating shaft. In this manner the optical disc camcorder provides improved recording and reproduction characteristic and improved tracking performance by way of preventing rolling generated by in the camcorder unit from being transmitted to internal base plate assembly and also preventing skew and oscillation of spindle motor shaft from being generated.

Optical disc camcorder

An optical head in which pre-formatted signals may be detected as variations in the amplitude or the phase in the pre-formatted signals are suppressed, and a recording and/or reproducing apparatus employing the optical head, are disclosed. The optical head includes a light source, an objective lensfor condensing a light beam radiated from the light sourceon a recording track of an optical recording medium, and a photodetector unitfor receiving the light beam reflected back from said recording track. The photodetector unitincludes a first light receiving sectionand a second light receiving section. With a track pitch Tp of the optical recording medium, the wavelength &#x3bb; of the light beam radiated from the light source, the numerical aperture NA of the objective lens and with &#x3bb;/(Tp&#xb7;NA)&#x2267;4/3, the first light receiving section receives the light of one of two light spot areas lying on both sides of a center area of a light spot of the reflected light beam passing through the center of the light spot for extending along the length of the recording track. The second light receiving section receives the light of the other of the two light spot areas.

Optical head and recording and/or reproducing apparatus

The present invention is directed to an optical head adapted for performing recording or reproduction of information signals with respect to an optical disc (), which controls light coupling efficiency with respect to light beams irradiated onto the optical disc () by light coupling efficiency adjustable element such as a liquid crystal element (), etc. in accordance with type of the optical disc (), recording surface of multi-layer optical disc and/or operation mode to change power of light beams irradiated onto the optical disc () to a large extent without excessively increasing change quantity of output power of a semiconductor laser element (). A beam splitter () divides incident light beams of P-polarized light at a predetermined ratio to allow the light beams thus obtained to be incident on a light detector () for disc surface power monitor.

Optical head and optical recording medium drive device

A current detector detects a driving current Im flowing through a light emitting device (laser diode); a temperature sensor is arranged in the vicinity of the light emitting device; a microcomputer is supplied with the outputs of the current detector and temperature sensor; a temperature correction coefficient specific to the light emitting device, obtained based on a driving current value IT1 at a temperature T1 and a driving current value IT2 at a temperature T2 (&gt;T1), is stored in memory; a deterioration threshold current Id for a detected temperature Ti is calculated; and when the deterioration threshold current Id for the detected temperature Ti is exceeded by the detected current, a driver is controlled so as to inhibit the supply of the driving current to the light emitting device. Since the operating temperature also is taken into consideration, deterioration of the light emitting device can be accurately estimated, thereby preventing erroneous recording/reproduction of data.

Deterioration estimating method for a light emitting device and a light

An apparatus for recording a signal on a disc medium driven by a servo circuit comprises, device for generating a laser beam for recording the signal on the disc medium, device for detecting a track jump of a scan of the disc medium by the laser beam, device for storing the signal during an occurrence of the track jump, and controller for controlling the laser beam generating device, track jump detecting device and storing device so that a recording operation by the laser beam is stopped during the occurrence of the track, and the signal stored in the storing device is recorded on a predetermined area of the disc medium after the record operation becomes to be possible.

Disc recording apparatus for recording a signal without losing the

In a sampled data transmitting apparatus in which the sampled data to be transmitted are divided into odd-numbered samples and even-numbered samples and arranged in different rows of a two-dimensional data array, and in which error correction codes are annexed to each row and to each column of the two-dimensional data array, the row arraying sequence in one of the odd-numbered or even-numbered rows is caused to differ from the row arraying sequence in the other of the odd-numbered or even-numbered rows so that odd-numbered data and even-numbered data continuous with the odd-numbered data are not arranged in one row. In this manner, even when error correction becomes impossible by the error correcting code for one row, interpolation remains feasible because there exist no odd-numbered data or even-numbered data contiguous to each other in the row.

Sample data transmission apparatus

A disk recording and reproducing apparatus using two light beams has a disk driving section for loading a disk-shaped record medium having recording tracks and for rotating the disk-shaped record medium, an optical system having a light beam generating source, a light beam splitting device for splitting a light beam to provide at least a main beam and a sub beam, an optical path forming device for respectively causing the main beam and the sub beam to become incident on two adjacent recording tracks in the disk-shaped record medium loaded on the disk driving section and a photo-detecting device for detecting the condition that at least the sub beam from the disk-shaped record medium loaded on the disk driving section is affected by the recording track. Also provided is a disk rotation control section for controlling the disk driving section such that a relative moving speed of the recording track relative to the main beam incident on the recording track becomes constant, a recording operation section causing the information to be recorded on the recording track on which the main beam becomes incident, and a reproducing operation section for generating a read-out information signal based on a detected output of the sub beam from the photo-detecting device. The resultant read-out information signal is written in a memory at a rate corresponding to the read-out information signal and the read-out information signal written in the memory is read out again at a predetermined reading rate to generate a reproduced information output.

Multiple beam optical disk apparatus with multiple clock extracting

An optically writable record of digital information is provided on an optically writable record disk having a reflection factor substantially higher than seventy percent, and is composed of first digital information including a plurality of program data and respective address data indicative of the individual addresses of the respective program data and being recorded with the latter sequentially along a first track in a first annular recording area of the record disk, and second digital information including table-of-contents data, identifying the plurality of program data, respectively, and being recorded sequentially along a second track which is in a second annular recording area of the record disk and which has a concluding end contiguous to a starting end of the first track so that, upon playback of the digital information record, the table-of-contents data and the plurality of program data and respective address data can be reproduced successively without interruption by a standardized compact disk player.

Optically writable record of digital information and recording apparatus

In a tape recorder of the type having a first or drive gear rotatable with the capstan by a motor, a second or driven gear rotated by the drive gear when in meshing engagement therewith and having a toothless portion to permit rotation of the drive gear independently of the second gear when the latter is disposed in a rest position with its toothless portion facing the first gear, an actuator in the form of a cam rotatable with the second gear and engaging a lever by which, for example, a head carriage is moved to its operative position for establishing the playback mode of the tape recorder in response to turning of the second gear, and a latching assembly normally holding the second gear in its rest position and being actuable, for example, for selection of the playback mode, to permit angular displacement of the second gear from its rest position into meshing engagement with the first or drive gear so as to be driven by the latter in a substantially complete revolution whereupon the latching assembly agains holds the second gear substantially in its rest position; a drive circuit is selectively operative to drive the motor at two different speeds, and a drive control circuit is operable simultaneously with actuation of the latching assembly to changeover the drive circuit from driving the motor at the higher of the two speeds to driving the motor at the other or slower of the two speeds which, for example, is standard for the playback mode. When the stop mode of the tape recorder is again selected, the drive control circuit again causes the motor to be driven at the higher speed.

Growing community of inventors

Kanagawa, Japan

Masaru Tezuka