Matches 151 - 200 out of 400 < 1 2 3 4 5 6 7 8 >
Match Document Document Title
5896353 Servo control apparatus for controlling position of device  
A position control apparatus 100 is provided with: an optical pickup 1 for reading information from a track formed on a optical disk DK by irradiating a light beam B to the track, detecting a...
5886963 Gain control device for servo control  
An automatic gain control device includes: reading unit for reading information signal from a recording medium; servo loop including servo control unit for controlling position of the reading unit...
5859816 Tracking error signal generating circuit  
A tracking control system for use in a digital video disc (DVD) system requires generation of a precise error tracking signal. A tracking control system has an optical detector for reading a light...
5841746 Apparatus for scanning an optically readable record carrier  
A device for optically scanning an information layer by means of a focused radiation beam. Radiation reflected from the information layer is made astigmatic by an oblique plane parallel plate and...
5835460 Multi-layered optical disk reproducing method with focus search  
To move an object lens out of focalization on a layer and to accelerate it upwardly, a drive signal DRV is set HIGH, and a focus OPEN signal is set LOW. After a value a counter exhibits at this...
5831949 Digital focus servo control apparatus for use in an optical disk system  
An apparatus efficiently compensates a focus error signal detected by a focus error detector in an optical disk system using an improved focus error compensation scheme. At an optical head, light...
5828637 Servo control device of optical disk recording and reproducing apparatus  
A servo control device of an optical disk recording and reproducing apparatus which is capable of performing tracking control and sled control by detecting radial shift indicative of a degree of...
5812503 Positioning control system having an optical beam and a servo-error signal generating circuit for accurately irradiating a desired position  
A positioning control system for performing recording/reproducing operations by irradiating an optical beam on a predetermined position on an optically recording medium includes a photo-detector...
5808983 Recording/reproducing apparatus and method for determining and generating a focus offset valve to focus at an optical storage medium  
The invention provides a recording and/or reproduction apparatus and a recording and/or reproduction method by which information can be recorded or reproduced accurately onto or from any of a...
5793720 Optical disk and reproducing apparatus including a focus search control device  
When an optical disk having a plurality of recording layers is loaded, in which layer-number data is recorded on the recording layer nearest to the signal reading plane and layer I.D. data is...
5771214 Optical information recording/reproducing apparatus capable of detecting tracking and/or focusing error and method therefor  
In an optical information recording/reproducing apparatus capable of executing a first recording method for recording information on either one of a land portion and a groove portion of a recording...
5761164 Gain control device for servo control  
An automatic gain control device includes: reading unit for reading information signal from a recording medium; servo loop including servo control unit for controlling position of the reading unit...
5757747 Tracking servo signal processing circuit and read apparatus using the same  
A tracking error signal is converted into digital data by an A/D converter. A compensation circuit performs gain and phase compensation operations in accordance with the frequency of the digital...
5757744 Optical scanning apparatus for a multi-layer record carrier, including a focus control circuit  
An optical beam in a scanning device is focused on an information layer of a multi-layer optical record carrier. A focus control circuit keeps the focal point of the beam on the information layer....
5757743 Electric circuit for providing a position indicator signal in a system for multilayer optical disk storage  
Laser light is focused in an accurate manner on selected layers in a multilayer optical disk recording system by means of an analysis of output electrical signals from a dithered source which...
5754515 Active alignment method for multilayer optical disk storage  
Laser light is focused in an accurate manner on selected layers in a multilayer optical disk recording system by means of an analysis of output electrical signals from a dithered source which...
5754507 Multi-layered optical disk reproducing apparatus with focus search  
To move an object lens out of focalization on a layer and to accelerate it upwardly, a drive signal DRV is set HIGH, and a focus OPEN signal is set LOW. After a value a counter exhibits at this...
5751674 Apparatus for controlling bias amount of focus error signal  
An optical information reproducing and/or recording system is provided with an optical system for irradiating a light beam to an information record surface of an information record medium and...
5745450 Focusing servo system and focus servo acquisition enable with multiple velocity acquisition modes  
A focusing servo system includes an objective lens which is driven to move toward and/or away from a recording medium during focus searching operations. The objective lens is driven at a first...
5740136 Disk driving device and method for optical recording and reproducion with acceleration/deceleration of focusing means being based on a focus error signal level  
A disk driving device for use in recording and/or reproducing data on an optical recording medium having a plurality of recording layers. When a focus jump operation is executed between the...
5732051 Focusing control apparatus using dynamic target value in relation to land/groove  
A focusing control apparatus is provided for controlling focusing of a light beam on a recording medium. The apparatus includes a control mechanism for maintaining the focusing state of the light...
5721718 Apparatus and method for discriminating the type of optical disk mounted into an optical disk reproducing apparatus  
An apparatus and method for discriminating an optical disk includes a spindle motor for rotating the optical disk, an optical pickup device for picking up data recorded the disk, a servo signal...
5708647 Laser power supply circuit as well as option recording and/or reading device comprising such a laser power supply circuit  
A laser power supply control circuit may, when the power supply is initially turned on, temporarily permit an excessive supply voltage which may damage the laser. To prevent that, but without...
5687147 Servo control method and apparatus for an opto magnetic disc  
A servo control method and an apparatus for an opto-magnetic disc swiftly converts a servo control system corresponding to a changed area when a current servo area is abruptly changed while...
5682372 Method and apparatus for playing back multilayer disk  
There is disclosed a method of playing back information from an optical multilayer disk having a plurality of recording disks stacked on top of each other, by the use of an optical pickup device....
5675561 Optical disc reproducing apparatus with mechanical shock detection  
An optical disc reproducing apparatus of the present invention has an objective lens for focusing light from the light source on a disc surface as a light spot, a focus actuator for driving the...
5675558 Seeking control apparatus and method for disk drives, using slew-rate limit for control output  
The purpose of the present invention is to provide a method and an apparatus for seeking-control for disk drives, in which (i) the step current waveform at the start of speedup or at the switching...
5663946 Optical disc having buffering areas capable of storing a pattern for obtaining tracking error signals and recording and/or reproducing apparatus therefor  
At the boundary between the program area and the recording area, buffering areas where no valid data exists are respectively provided in the program area and the recording area. These respective...
5659535 Method for retrieving data from a storage device  
A method for detecting transitions in an input signal having a DC component. The method includes the steps of generating a threshold signal from the input signal, comparing the input signal to the...
5642340 Device for controlling focus of an optical disk apparatus  
A focusing control device for use in an optical disk apparatus of the present invention is provided with: an error-signal generation circuit for generating a focus error signal; a detection circuit...
5631886 Tracking control apparatus for optical disk  
Disclosed is a tracking control apparatus for an optical disk. The optical head of the optical disk system generates a tracking error signal for servo tracking. The tracking error signal is also...
5627813 Optical information recording and/or reproducing apparatus and method with auto power control function for two light sources  
An optical information recording and/or reproducing apparatus radiates a leading light beam from a first light source and a trailing light beam from a second light source to follow the leading beam...
5627807 Optical disk apparatus with focus bias means  
An optical disk apparatus with a focus bias circuit including a focus servo device for an optical pickup, wherein a return light beam from an optical disk is received by a photo detector, then a...
5623463 Method for determining a focusing control operation position in an opto-magnetic disc recording/reproducing apparatus  
A method for determining a focusing control position in an opto-magnetic disc recording/reproducing apparatus, shortens the focusing time required for determining the focusing control position of...
5623460 Circuit and method for searching track on CD  
A track search circuit includes a command decoder which decodes command data sent by a microcomputer and stored in a command register and outputs signals commanding a track jump and commanding...
5621717 Reading optical disks having substrates with diverse axial thicknesses  
An optical disk player reads either thin-substrate disks or thick-substrate disks. The disk players optical system is designed for reading the thin-substrate optical disks and has an effective...
5619387 Disk storage device with spiral data track and incremental error offsets in angularly spaced imbedded concentric servo patterns  
A disk drive stores multimedia data in long spiral data tracks. The tracks on opposite surfaces of the disk spiral in opposite directions, so that a track on one surface can be read as the actuator...
5610887 Error correcting apparatus with error corecting signal holding function  
An error signal generating circuit for adjusting a position of a sub-beam on an optical disc to a correct one. A timing circuit generates a test signal so that a driver drives a tracking coil. As a...
5610885 Linear drive mechanism for use in an optical disk device  
According to an optical head device access mechanism, drive coils, which provide propulsive force for moving an objective lens, and position sensors, which detect the position of the slide base,...
5602820 Method and apparatus for mass data storage  
The present invention discloses apparatus and method for decoding high density data encoded in a digital recording media as a series of tags comprising an information bit pattern including a...
5596557 Disc skew detecting apparatus using two skew detectors arranged along the reproduced track  
A disc skew detecting apparatus having a skew sensor for detecting skew of a disc in which information signals are recorded and reproduced with an optical pickup device, the skew sensor being...
5587985 Signal processing device for an optical information reproducing apparatus  
A signal processing device used for an apparatus capable of optically reproducing information from a recording medium is disclosed. In the signal processing device, a signal including information...
5566151 Optical devices having array detectors with light receiving photo arrays larger than an incident laser beam cross-section  
An optical device has an optical array detector with an array of optical receptors (each receptor is an individual photo detector) that has a greater cross-sectional extent than an impinging light...
5566148 Optical disk tracking system for searching a target track based on a table of compensation reference velocity  
When a optical head is moved towards a appointed track, a reference velocity is read out from reference velocity calculation data in accordance with the number of remaining tracks latched in a...
5559772 Information recording and/or reproducing apparatus and method for adjusting an offset amount of a focusing servo circuit  
An information recording and/or reproducing apparatus has an auto gain controller for controlling the amplitude level of a reproduction signal read out from a recording medium to a predetermined...
5559770 Automatic gain control method and device for servo loop, and information recording and/or reproduction apparatus  
In an automatic gain control device, an error signal generated based on output signals from a divided sensor is inputted to an operational amplifier. A sum signal of the output signals from the...
5559768 Tracking following apparatus for optical disk device  
A tracking following apparatus for an optical disk device includes an objective for forming a light spot on an optical disk, a fine actuator for driving the objective, a coarse actuator for driving...
5559766 Rotary drum tape recording apparatus with controlling optical recording tracks using stored results of scanning of reference tracks  
An optical recording method and an optical recording apparatus enable recording information on recording tracks substantially corresponding to ideal reference tracks, on an optical recording medium...
5555237 Contamination detection apparatus and method using write power calibration values  
A system to monitor write power calibration values in an optical drive to detect media and lens contamination, and take appropriate remedial action when contamination is found. A laser device...
5550800 Pick-up with adaptation  
In an optical recording apparatus light is directed to and reflected from a recording medium to recover recorded information. The intensity of direct and reflected light is measured and the ratio...
Matches 151 - 200 out of 400 < 1 2 3 4 5 6 7 8 >