|
Match
|
Document |
Document Title |
|
|
5088078 |
Optical pickup apparatus
An optical pickup apparatus in which a laser beam reflected from an optical memory medium is separated and incident to a light-receiving element having a plurality of divided light-receiving faces...
|
|
|
5086420 |
Focus control apparatus for use with an optical disk for determining whether a focused state has been obtained
Disclosed is an optical disk apparatus in which light which returns from a recording medium is led to an photodetector composed of a plurality of light-receiving elements, and focusing is...
|
|
|
5084661 |
Position control system for information storage system
A position control system for an information storage system, for example, an optical disc system, includes a stepping motor for moving a read-write head and a DC motor for moving a beam reflecting...
|
|
|
5084848 |
Feedback control apparatus in an optical recording and reproducing device
A feedback control apparatus in an optical recording and reproducing device for recording, reproducing and/or erasing data from an optical recording medium projects a light beam emitted from an...
|
|
|
5079755 |
Apparatus for detecting a deviation of a reading position for use in a disc player
An apparatus for detecting a deviation of reading position for use in a disc player. A detection signal of the deviation of reading position is generated if a sync signal to be extracted from the...
|
|
|
5067118 |
Position detecting device for use by switching plural alternating signals having different phases from each other
A position detecting device includes a: generator for generating a plurality of phase-shifted signals which are alternately changed in accordance with changes in position or angle of a movable...
|
|
|
5065385 |
Time base control system with coarse and fine correction for a spindle servo
An apparatus for reading information performing a coarse adjustment of the time base by means of a phase difference between a reproduced sync signal obtained from a read signal read from a...
|
|
|
5054013 |
Track transverse detection signal generating circuit
A track transverse detection signal generating circuit in a LD or a CD player, which comprises a presence signal amplifier for amplifying a presence signal indicating that an optical spot for...
|
|
|
5036508 |
Spindle servo unit for disk playing device
A spindle servo unit for disk playing device detects a synchronizing signal in an information signal read from a recording disk and generates a signal synchronized with the detected synchronizing...
|
|
|
5036505 |
Data reproduction arrangement for recalling data readable with an optical pickup from a recorded medium
A data reproduction arrangement for recalling data that can be read out with an optical pickup from data storage tracks of a recorded medium, in which a beam of light is focused on the recorded...
|
|
|
5034939 |
Apparatus for selectively playing back and recording data on a disk in which the bit error rate is held minimum
An arrangement for selectively playing back and recording data in which a rotating disk-shaped recording medium is provided with data storage tracks. An optical system reads the stored data by...
|
|
|
5023857 |
Optical information storage apparatus including eccentricity compensator
An optical information recording and/or read system comprises an optically readable record carrier (1) and an optical read and/or recording apparatus (FIG. 2). The record carrier (1) is provided...
|
|
|
5020044 |
Head positioning system for use in information recording/reproducing device with means for deriving track crossing signal from tracking error signal
An optical disk system comprising a head positioning system for positioning a head at a desired one of the tracks of an optical disk, and a tracking servo system for maintaining the head at the...
|
|
|
5018125 |
Signal processing circuit for detecting a tracking error for an optical disk apparatus
A signal processing circuit for an optical disk apparatus to detect a sine wave tracking error signal obtained when an optical spot on an optical disk moves in a direction of a radius of the...
|
|
|
5018123 |
Optical information recording medium and method for recording information on said medium and reproducing information therefrom
In an optical information recording medium of the type wherein information is recorded or reproduced when a light beam scans each of a plurality of mutually parallel tracking tracks, an auxiliary...
|
|
|
5010535 |
Apparatus and process for measuring data disk runout and acceleration parameters
Runout and acceleration measurements are provided for a disk drive type device using a closed loop actuator to position a transducer element relative to circular and/or spiral tracks on a recording...
|
|
|
5003521 |
Optical disk discriminating device
An objective lens (3) of an optical pick up head (10) is moved in a direction of the optical axis, and a signal level of the output detected by the optical pick up head (10) before and after a...
|
|
|
5001732 |
Track counter for optical disk
The track counter for optical disk in accordance with the present invention, that counts the number of tracks a light beam passes upon when an optical head moves over an optical disk in the radial...
|
|
|
4998233 |
Acquiring focus in optical systems using a focus error signal and a laser drive signal
A focus acquire circuit for use in optical systems, such as optical data recorders and players, uses up to three parameters signals to indicate an in-focus condition. The zero crossing of a focus...
|
|
|
4982392 |
Stabilized optical pick-up device inhibiting the effect of the focus error signal at the start and end of a data region
An optical pick-up device for use in an optical information recording/reproducing apparatus carries out a focusing and tracking control operation to keep the optical pick-up device located in a...
|
|
|
4977551 |
Optical disk tracking control system and method having normalized tracking error control signal
A tracking servo control system of an optical disk system produces a tracking control output signal for control of a tracking actuator which is adjusted to enable accurate positioning of a focussed...
|
|
|
4972398 |
Optical disk drive with servo loop for detecting defective disks
An optical disk recording and reproducing apparatus is provided with an element in a servo system circuit, which element is provided high response characteristics to run out frequency. Output of...
|
|
|
4965782 |
Off-track bit shift compensation apparatus
Many of the data read errors encountered in an optical disk system are due to reading off track. These errors are the result of bit shift, which is the shifting of the data transition relative to...
|
|
|
4924454 |
Servo apparatus with offset compensation
A servo loop arrangement for the reproduction of data from a record medium has interleaved pulse trains of opposite polarity pulses applied to it to add to the servo loop control signal which...
|
|
|
4907214 |
Eccentricity correction apparatus for an optical disk device
An optical disc apparatus includes a tracking device which positions the beam light on the recording track of an optical disc in order to carry out at least recording or reproducing of information...
|
|
|
4896310 |
Light beam control arrangements for optical disc apparatus
A light beam control arrangement for an optical disc apparatus in which a tracking servo control for a light beam projected onto an optical disc is performed in accordance with a tracking error...
|
|
|
4891798 |
Optical disc player with focus control for preventing erroneous focus on outer surface of optical disc
An optical disc player in which prior to a focus servo control carried out by a focus control mechanism on the basis of an indication of a focus error signal, focusing control means causes an...
|
|
|
4875203 |
Tracking servo signal generating device for an optical disc
An optical disk reproducing apparatus of the type in which a tracking control is performed by projecting a controlling laser beam to the center of each of a plurality of V grooves formed on an...
|
|
|
4860271 |
Servo circuit for generating a tracking error signal for optical disk player
A servo circuit for use in an optical disk player or the like, which can track a disk having a large eccentrically without abnormal sampling of the RF signal produced as a result of scanning the...
|
|
|
4833664 |
Servo system for scanning the same track circumference of a spiral track on a disc shaped recording medium
During the storing of a tracking error signal and an index detection signal in memories in relation to rotating means for a recording medium, an error is detected when the number of index detection...
|
|
|
4825137 |
Time base control system for a spindle servo
A time base control system for a spindle servo motor in which the time base is both coarsely controlled and finely controlled. According to the invention, when the recording head is alternately...
|
|
|
4807206 |
Track jump detection system
A system for recording or reproducing a signal by focusing and irradiating a light beam on a record carrier from a light source while controlling the light beam to always scan the track on the...
|
|
|
4786794 |
Focus servo-circuit with ordered reference level setting means
In order to focus light beams which are projected onto an optical recording medium, the focusing optical system is moved in a vertical direction to the surface of the recording medium. A focus...
|
|
|
4769803 |
Optical information recording and/or reproducing apparatus
In order to detect the position of a lens holder held resiliently by a pair of plate springs and fitted with an objective lens, a sensor is fitted in a through hole made in at least one of a pair...
|
|
|
4757487 |
Method and apparatus for detecting track crossings on an optical disc
In a method of detecting track crossings on an optical disc, a light source irradiates a light beam onto an optical disc having guide tracks in the form of a recess and the light beam is reflected...
|
|
|
4755980 |
Optical disk and recording/reproducing device for optical disk
In a device for recording or reproducing information by using a light beam, there is provided an optical disk comprising a base plate, a recording layer formed on the base plate, tracks provided...
|
|
|
4750163 |
Pick-up head abnormality detector for optical recording/reproducing apparatus
A device for detecting the abnormality of an optical pick-up head has a laser diode for emitting a light beam through an optical system to a reference reflective region formed at a predetermined...
|
|
|
4748610 |
Servo system in data reading apparatus
A servo system for controlling the position of a reading beam in an optical video disc player or the like in which an offset signal for cancelling an offset in an error signal used for controlling...
|
|
|
4740940 |
Optical information read apparatus
An optical information read apparatus for optically reading information recorded on a recording medium includes an optical head for producing two detected signals whose phases vary according to a...
|
|
|
4740679 |
Disc focus servo-circuit with ordered reference level setting means
In order to focus light beams which are projected onto an optical recording medium, the focusing optical system is moved in a vertical direction to the surface of the recording medium. A focus...
|
|
|
4733066 |
Device for controlling the movement of a focal point of a light beam used for detecting recorded information
A device for controlling the movement of a focal point of a light beam for detecting recorded information on a recording medium, comprises a focus actuator connected to a focal lens for focusing...
|
|
|
4731771 |
Tracking servo setting method and apparatus
This invention relates to a track setting method for a tracking servo system in an optical disk device and a device therefor. According to this invention the track passage velocity when the light...
|
|
|
4730290 |
Defect detecting optical apparatus enabling recording in an alternate sector or track
An optical recording/reproducing apparatus for recording and reproducing information along tracks on an optical disc by irradiating the optical disc with a laser beam comprises a tracking error...
|
|
|
4718068 |
Stabilized laser device of optical information recording/reproduction apparatus
In a stabilized laser device of an optical recording/reproduction apparatus, in the reproduction mode, a laser beam of reproduction level is radiated on an optical disk, and data is read from the...
|
|
|
4718050 |
Optical scanner and reader for information contained in light reflected from moving optical records
The invention provides a reader and scanner, in particular for the reading of audio and/or video information recorded on plate-shaped information carriers. A scanning head can be pivoted around an...
|
|
|
4712206 |
Tracking error signal detecting device with a two-beam system for use in an optical information memory
A tracking error signal is detected by irradiating an information pattern recorded on an information carrying member with first and second light beams, the second light beam being incident on the...
|
|
|
4703467 |
Video disc read back scanner
A video signal play back device derives video signals from successive tracks formed as a continuous spiral on a video disc using a light source and a lens system, which is carried by a rotatable...
|
|
|
4698795 |
Tracking servo device
A tracking servo device for controlling the relative position in the radial direction of a recorded disc between an information reading point of a pick-up and a recorded track having an improved...
|
|
|
4683560 |
Microprocessor controlled focussing servo acquisition
In an auto-focussing system, an actuator which moves together with an objective lens is vertically movable against a rotating optical disc and radiates a light beam so as to form a light spot on an...
|
|
|
4683561 |
Smooth lock-in of servo control when switched on
An apparatus for playing optical discs is described, in which for a smoother locking-in of the focus servo control the focussing error signal is initially derived from the amplitude of the h.f....
|