Matches 251 - 300 out of 390 < 1 2 3 4 5 6 7 8 >
Match Document Document Title
5289446 Device for scanning a record carrier  
A device for scanning a record carrier having essentially parallel tracks produces detection signals (AS, . . . , FS) which depend on the location of the scanning point relative to the tracks and...
5287339 Optical information processing apparatus for holding a lens at a predetermined position along a tracking path at pulling-in of focusing control  
An optical information processing apparatus for irradiating a focused light beam to an optical recording medium to record and/or reproduce information. The apparatus includes a device for...
5286965 Anticollision system for objective lens in an optical data recording apparatus  
An anticollision system for an objective lens for use in an optical data reproducing apparatus. The apparatus is constructed so that the relative distance between the objective lens and a data...
5285432 Track jump control circuit  
A track jump control circuit having a pick-up for reading information stored on a disc, a motor for moving the pick-up in a radial direction of the disc, a speed detector for detecting the moving...
5282184 Focus control device of an optical disk apparatus  
An automatic focusing device of an optical disk apparatus with a capability of automatically focusing a light beam at an optimal position relative to the surface of a track of an optical disk by a...
5268891 Optical recording/reproducing apparatus which reduces seek time by timing initiation of tracking control based upon characteristics of record medium vibrations relative to an optical pick-up head  
An optical recording/reproducing apparatus effects a seek operation by moving an optical pick-up, which includes an objective lens for projecting a light spot onto an optical card, in a tracking...
5268888 Focusing servo apparatus for an optical disc  
The present invention is directed to apparatus. Upon actuation, a system controller controls a digital-to-analog converter to derive a pulse-shaped wave sweep signal. This sweep signal is supplied...
5265085 Simultaneous MO and ROM optical disk signal detection  
A circuit for simultaneously detecting both MO and ROM signals reflected from an optical disk so that both signals are present and useable without switching from one to the other. The circuit...
5257252 Adaptive control system for a disk drive actuator  
A servo loop controls an actuator and read head, the loop being responsive to training signals to cause the actuator to move the read head. An error signal is produced that indicates a less than...
5257250 Tracking-control target-position adjustment method  
A tracking control target position adjusting track is provided on a recording carrier, where the track contains a preliminarily recorded first position-adjusting signal adjoining one side of track...
5257251 Single loop servo-positioning systems having means for changing the dynamic range of a position-error signal with speed of the relatively movable members  
A single loop servo is used for positioning a lens holding element with respect to an optical disk. The dynamic range of the error signal used in the positioning is dynamically frequency shifted...
5253241 Optical recording apparatus for recording auxillary signals used for focus control  
An optical recording apparatus for automatically compensating for focus offset which cannot be compensated for with a conventional focus servo circuit. A plurality of auxiliary signals differing...
5253238 Arrangement for producing precise tracking error signal for optical disk device  
To produce a tracking error signal (28) precisely indicating a positioning error of an optical beam with respect to one of recording tracks in a radial direction of an optical disk (12), a...
5249168 Method and apparatus for initializing optical disk drive apparatus  
A method and apparatus for initializing disk drive apparatus wherein a pickup head is positioned near the mid-range of tracks on a disk by moving the head at power-on to an innermost track and...
5237549 Magneto-optical disk storage device having optical head applicable to different types of magneto-optical disks  
In an optical head in a magneto-optical disk storage, an angle of a polarized light surface of a laser beam can be adjusted so that the strength of a tracking error signal can be maximized....
5233585 Acquiring focus in an optical disk system using a time and shape modified focus error signal  
The focus acquire system on optical disk recorder as well as other optical systems, signal processes a focus error signal FES to produce a modified FES which has a peak amplitude occurring closer...
5224083 Objective lens driving apparatus  
From the start of descending of a disk-shaped recording medium in a direction of approaching an objective lens in the optical axis direction by a loading mechanism until it is set at a specified...
5216651 Pickup-drive stabilizing apparatus for an optical disc player  
A pickup driving apparatus, and particularly, a pickup-drive stabilizing apparatus for an optical disc player includes: a detector for detecting an inertia of a pickup relative to a movement speed...
5210735 Optical recording/reproducing system, having function of detecting dirt deposition on optical pickup  
An optical recording/reproducing system comprising an optical pickup for recording and/or reproducing of data with respect to an optical recording medium. A reflection factor and a signal amplitude...
5206847 Information recording disk, and information recording/reproducing method and apparatus utilizing the same  
There is disclosed an information recording disk, and a method and apparatus for information recording and reproduction, enabling secure tracking and full utilization of the recording capacity. For...
5199015 Optical recording/reproducing device having means for adjusting servo loop gain and phase characteristics  
An optical recording and playback device for irradiating a light beam spot on a track of a data carrying medium at a target condition includes a servo error signal detector for detecting a...
5195076 Defect detection circuit for optical pick up device  
A defect detection circuit for optical pick up device having a record medium on which a track is formed which track has a plurality of segments formed in series along the track. The circuit...
5193081 Track-accessing controller for optical disks  
Disclosed is an optical disk apparatus applied to a data writing/reproducing operation of a sample-servo formatted optical disk having a clock pit and two wobbled pits in each of servo regions. A...
5184338 Optical disc system with improved track jumping operation  
In an optical disc system having a tracking actuator for driving a light spot on an optical disc in a radial direction thereof; a photodetector for detecting off-track information in respect of the...
5184337 Optical recording/reproducing apparatus having means for periodically supervising drive current supplied to actuator  
The results output from a comparator, which makes a comparison to determine whether or not the drive current to be supplied to a focusing/tracking actuator of an optical system in which light beams...
5181194 Writing device for optical memory card  
A writing device for an optical memory card is disclosed. In this writing device, tracking correction is performed by moving a mobile objective lens of an optical system in the transverse direction...
5179545 Tracking control apparatus for controlling the tracking of a target track  
A tracking control apparatus is provided for controlling a displacement error between a pickup system and a track when reproducing information recording on an information-recording and reproducing...
5177718 Optical disk apparatus  
An optical disk apparatus comprising a head having an objective lens, a tracking controller, a CPU, and a counter. The CPU determines a tracking error if the count of the counter is greater than a...
5172353 Track seeking control apparatus for use in data recording/reproduction systems having data tracks thereon  
A track seeking control apparatus includes an optical head for generating a signal comprising a train of track cross pulses when it crosses tracks on a recording medium. A first counter counts the...
5168488 Optical recording and reproducing apparatus  
In an optical disk apparatus for recording and reproducing data using light beams, the light reflected from a record mark area provided on an optical disk is detected and the amplitude of the...
5161141 Optical disk system having a stably driven servomechanism for a laser system for reading signal tracks  
An optical disk system comprises a laser system for optically reading a signal track on an optical disk by means of a laser beam so as to generate an electrical read-out signal, and a servo system...
5161243 Tracking system for an optical recording/reproducing apparatus having a plurality of light spots  
In an optical recording and reproducing apparatus which forms at least first and second light spots on a track of an optical recording medium to record, reproduce or erase information, a movable...
5157249 Miniaturized optical pick-up with high sensitivity focusing error detecting device  
Optical pick-up for reading information recorded on an optical card includes a light emitting diode, collimator lens, beam splitter and objective lens arranged so a de-focused illuminating light...
5157555 Apparatus for adjustable correction of spherical aberration  
Apparatus for correcting spherical aberration of light reflected from a surface of an information-bearing layer of an optical disk and traversing through a substantially transparent substrate...
5151888 Optical information processing apparatus in which the output of an optical sensor is replaced by a reference signal during the occurrence of malfunction  
An optical information processing apparatus effects recording and/or reproduction of information by scanning information tracks of an optical recording medium by at least one condensed light beam...
5148423 Method of and circuitry for compensating offset voltages in a focusing and/or tracking circuit  
A method for compensating offset voltages selectively in a focusing circuit that focuses a beam from a source of light on a recording medium and in a tracking circuit that positions a beam of light...
5148425 Overshoot minimizing tracking servo apparatus  
A tracking servo apparatus is disclosed which detects the change in the level of tracking error signal per unit time when the information reading spot passes a position on the track at its center...
5148420 Recording information apparatus having a head speed detector  
A recording information apparatus for a recording medium having a track previously formed on the recording medium. The apparatus includes an objective lens for projecting a light beam on the...
5144609 Apparatus for tracking an optical disc  
In an apparatus for tracking an optical disc, speed in acquiring a steady tracking condition is significant. That is, if the light beam is subjected to feedback while it is positioned in a positive...
5142517 Focus adjustment system for optical disk apparatus  
A focus adjustment system for an optical disk apparatus has a monitor detector that detects the power of a light beam emitted from a laser, and a peak detector produces a peak-detect signal when...
5140576 Method of and apparatus for setting focusing control into operation  
A method of and an apparatus for setting into operation a focusing control for bringing a focal point of a beam onto a recording surface of an optical disk such that the beam reproduces signals...
5136568 Tracking circuit for guiding a beam of light along data tracks of a recorded medium  
A tracking circuit for guiding a beam of light along data tracks of a recorded medium as compact disks and video disks, in which the recorded medium reflects a light beam onto a photodetector. The...
5136566 Focus actuator driving apparatus  
A driving circuit drives an actuator in accordance with either a driving signal or a focus error signal that is selected by a switching circuit. A capacitor, which is inserted in a feedback loop of...
5132948 Phase comparing apparatus and focus error detecting apparatus  
A phase comparing apparatus which outputs a signal of an amplitude corresponding to phase difference between a first and second signals, includes a difference signal operating device for outputting...
5123002 Disc player servo device  
A servo device for a disc player detects when the level of an error signal formed according to the output signal of the pickup is equal to or higher than a predetermined value, to provide a...
5121219 Spindle servo utilizing a vertical sync mark  
In a disk recording/reproducing apparatus, phase control of a spindle servo system is made to be smaller than a range of time base control of a time base servo system, so as to obtain spindle servo...
5117410 Optical disc apparatus with rapid and stable accessing capability  
An optical disc apparatus comprising an optical servo loop and a velocity servo loop to control the velocity of a pickup to zero, wherein the two servo loops are selectively switched in accordance...
5109367 Optical information recording and reproducing apparatus performing focus and/or track control by normalized error signals  
For an output signal of an error signal generating circuit generating a focus error signal and/or track error signal, it is materialized that a highly precise servo system can sufficiently deal...
5095474 Accessing apparatus for optical information recording and reproducing apparatus  
The accessing apparatus, which is to be used for an optical information recording and reproducing apparatus, controls the speed of a light spot and accesses the light spot to an object track. The...
5090000 Height adjusting device for a pickup  
A height adjusting device for adjusting the height of a pickup, comprises a support mechanism for supporting the pickup on the carriage in a manner that a position of the pickup along the axis of...
Matches 251 - 300 out of 390 < 1 2 3 4 5 6 7 8 >