Discovision Associates

Other

Noboru Kimura

Ronald G Vitullo

Yasuhiro Yamazaki

Wen-Yung Yeh

An optical disk includes a plurality of tracks that are arranged in a predetermined number of zones. Each track is divided into a plurality of sectors. The sector number is different in each zone. The sector increases in number moving outwardly on the disk. The optical disk also includes a format marking. The format marking includes a sector field for each sector. The format marking is erasably recorded.

Optical data system and optical disk relating thereto

An equalizer for producing an equalized signal from an input signal. The input signal has a DC component. The equalizer includes a programmable filter and equalizer. A detector for generating a threshold signal from a preprocessed signal. The preprocessed signal is generated from the equalized signal. A comparator for comparing the preprocessed signal to the threshold signal to produce an output signal. A tracking device for tracking the DC component from the output signal.

Retrieving data from a storage device using programmable filter and equalizer

An encoder converts a binary data word to a binary code word. The encoded bits have first and second binary values at a predetermined clock interval. A pulse generator responds to the encoded bits to generate energizing pulses during each clock interval in which the encoded bits have the first binary value. The energizing pules have a uniform duration less than the clock interval. A laser responds to the energizing pulses for recording on a medium.

Storing data on a medium in an optical system

An apparatus for recording data includes a source of digital data arranged into data words having a given number of bits and a converter that converts the data words to code words having one more bit than the given number using a group code recording format. The code words include a binary signal having first and second binary values at a given clock interval determined by a bit rate of the code words. The apparatus also includes a storage disk having a recording surface, a drive member for rotatably driving the disk, a laser having a focused beam, and a control assembly for directing the laser at the recording surface so that the beam accesses one of a plurality of concentric tracks on the recording surface. A circuit assembly provides a driving signal utilized for generating energizing pulses having a duration less than the clock interval when the binary signal has the first binary value. A pulse generator applies the energizing pulses to the laser to activate the laser responsive to the energizing pulses so that the laser is turned on and off even when the binary signal does not change value from one bit to the next. A high density optical disk including a plurality of tracks arranged in a predetermined number of zones may be utilized in conjunction the apparatus, which may be further incorporated into an optical data storage and retrieval system.

Optical data system and high density optical disk relating thereto

An apparatus and method for retrieving densely stored data from various types of magnetic media. A medium is scanned to provide an input signal. The input signal is conditioned through differentiation, equalization and partial integration. Positive and negative signal peak detectors are connected to the conditioned signal, and a threshold signal is generating corresponding to an average or midpoint of the measured positive and negative signal peaks. An output signal is generated by comparing the conditioned signal and the threshold signal. The DC component of the input signal is accounted for by feeding back the output signal and adjusting the threshold signal based on the duty cycle of the output signal.

Data recovery with differentiation and partial integration stages to

A first write encoder encodes digital data in a first, high-density format. A second write encoder encodes digital data in a second, low-density (i.e., ANSI) format. A first read decoder decodes digital data from the first format. A second read decoder decodes digital data from the second format. A disk drive receives a replaceable 90 millimeter optical disk. A read/write head reads encoded data from and writes encoded data to a 90 millimeter optical disk received by the drive. In a first mode, the first write encoder is connected between a source of digital data and the read/write head, and the first read decoder is connected between the read/write head and the utilizing apparatus. In a second mode, the second write encoder is connected between the source and the read/write head, and the second read decoder is connected between the read/write head and the utilizing apparatus. Control electronics switch between the first and second modes, depending upon the format in which data is recorded on the disk received by the disk drive. An 8/9 GCR encoder and a laser pulse generator are used in the first write encoder to record data on the optical media to increase the storage capacity. Improvement in timing is accomplished with write compensation and signal equalization.

Optical data storage and retrieval system and method

A data generator assembly for use in retrieving stored data from an information storage medium. The data generator assembly includes a positive peak detector for receiving a preprocessed signal having a predetermined waveform including positive peaks, negative peaks, and a DC component. The positive peak detector is utilized to measure and track the positive peaks to output a positive peak signal. A negative peak detector measures and tracks the negative peaks to output a negative peak signal. The data generator assembly also includes a voltage divider for averaging the negative peak signal and the positive peak signal and generating a threshold signal representing the approximate peak-to-peak midpoint of the preprocessed signal which varies with the DC component. A comparator is provided for comparing the preprocessed signal with the threshold signal. The comparator generates an output data waveform signal indicative of the stored data on information storage medium.

Data generator assembly for retrieving stored data by comparing

A first write encoder encodes digital data in a first high density format. A second write encoder encodes digital data in a second low density, i.e. ANSI format. A first read decoder decodes digital data from the first format. A second read decoder decodes digital data from the second format. A disk drive receives a replaceable 90 millimeter optical disk. A read/write head reads encoded data from and writes encoded data to a 90 millimeter optical disk received by the drive. In a first mode, the first encoder is connected between a source of digital data and the read/write head, and the first decoder is connected between the read/write head and utilizing apparatus. In a second mode, the second encoder is connected between the source and the read/write head, and the second decoder is connected between the read/write head and the utilizing apparatus. Control electronics switches between the first and second modes, depending upon the format in which data is recorded on the disk received by the disk drive. An 8/9 GCR encoder and a laser pulse generator are used in the first write encoder to record data on the optical media to increase the storage capacity. Improvement in timing is accomplished with write compensation and signal equalization.

Method and apparatus 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 threshold signal to thereby generate an output signal, and adjusting the threshold signal in response to the output signal. In one preferred embodiment, the method is employed to retrieve data from an information storage device.

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Torrance, CA, United States of America

Noboru Kimura