Abstract: An optical beamsplitter comprises a right angle prism having a hypotenuse and two legs wherein the hypotenuse includes an optically selective coating deposited thereon. An optical element is positioned adjacent the hypotenuse such that the hypotenuse and the optical element form a beamsplitting interface. Various optical elements are utilized to achieve the desired spatial and angular relationships between incoming and outgoing light beams. Several embodiments are disclosed wherein the optical element can comprise a flat plate for providing spatial offset, a wedged plate for producing spatial and angular offset, a lens for adding optical power, or a faceted thin plate.

Abstract: An optical system for determining aberration in a source beam by comparison of a test beam with a reference beam. The optical system includes a test source for producing a source beam having a spacial intensity distribution including an aberration component, a wavefront analyzer for processing a fringe signal associated with the aberration component, and an interferometer. The interferometer is provided with a beamsplitter for splitting the source beam into a test beam and a reference beam, an imaging device for detecting the test beam and the reference beam, and a mirror disposed in a test beam path for reflecting the test beam toward the imaging device. The interferometer also includes a micromirror disposed in a reference beam path for reflecting a portion of the reference beam toward the imaging device and a piezoelectric translator operatively linked to the mirror and controlled by the wave front analyzer. The mirror is capable of moving relative to the path of the test beam.

Abstract: A multi-standard video decompression apparatus has a plurality of stages interconnected by a two-wire interface arranged as a pipeline processing machine. Control tokens and DATA Tokens pass over the single two-wire interface for carrying both control and data in token format. A token decode circuit is positioned in certain of the stages for recognizing certain of the tokens as control tokens pertinent to that stage and for passing unrecognized control tokens along the pipeline. Reconfiguration processing circuits are positioned in selected stages and are responsive to a recognized control token for reconfiguring such stage to handle an identified DATA Token. A wide variety of unique supporting subsystem circuitry and processing techniques are disclosed for implementing the system.

Abstract: An MPEG video decompression method and apparatus utilizing a plurality of stages interconnected by a two-wire interface arranged as a pipeline processing machine. Control tokens and DATA Tokens pass over the single two-wire interface for carrying both control and data in token format. A token decode circuit is positioned in certain of the stages for recognizing certain of the tokens as control tokens pertinent to that stage and for passing unrecognized control tokens along the pipeline. Reconfiguration processing circuits are positioned in selected stages and are responsive to a recognized control token for reconfiguring such stage to handle an identified DATA Token. A wide variety of unique supporting subsystem circuitry and processing techniques are disclosed for implementing the system, including memory addressing, transforming data using a common processing block, time synchronization, asynchronous swing buffering, storing of video information, a parallel Huffman decoder, and the like.

Abstract: An apparatus is described for mounting an actuator lens within an optical disc carriage held by a baseplate assembly. The apparatus includes a frame, a cradle assembly mounted to the frame with at least one degree of freedom of motion, a tower assembly mounted to the frame, a lever assembly rotatably mounted to the frame, and a gripper assembly mounted to the lever assembly. The cradle assembly includes a baseplate alignment assembly having a source of radiant energy for projecting a beam of radiant energy, means for determining the tilt alignment of the beam with respect to the tower assembly, and a plurality of tilt actuators for aligning the tilt of the beam with respect to the tower assembly. The tower assembly includes a video camera having a camera lens, a tower magnifying lens, and a monitor for displaying a presentation of a beam of radiant energy passing through the tower magnifying lens and into the video camera.

Abstract: An integrated CMOS circuit is disclosed for deinterleaving transmitted data packets. The circuit operates with a RAM buffer that is no larger than a block of interleaved data. An optimized addressing scheme is provided that minimizes on-chip hardware. The circuit provides an orderly initialization of the buffer, and a suitable emptying process during a channel change or other interruption of data flow.

Abstract: 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.

Abstract: A Colpitts type oscillator circuit for mitigating the effects of undesired oscillator ringing when write pulses are supplied, such as those encountered in compact disc, laser disc, and magneto-optical players or recording devices. Circuit elements are provided for mitigating the effects of oscillator ringing including replacement of an inductor with a suitable resistive load and an oscillator supply voltage maintained above a predetermined minimum voltage which is a function of the specific values of the related circuit elements.

Abstract: An apparatus is described for aligning an actuator lens of an optical disk drive or the like within a baseplate assembly. The apparatus comprises a frame, a cradle assembly mounted to the frame with at least one degree of freedom of motion, a tower assembly mounted to the frame, a lever assembly rotatably mounted to the frame, and a gripper assembly mounted to the lever assembly. The cradle assembly includes a baseplate alignment assembly comprising a source of radiant energy for projecting a beam of radiant energy, means for determining the tilt alignment of the beam with respect to the tower assembly, and a plurality of tilt actuators for aligning the tilt of the beam with respect to the tower assembly. The baseplate alignment may further comprise means for determining the lateral alignment of the beam with respect to the tower assembly and a plurality of lateral actuators for aligning the beam laterally with respect to the tower assembly.

Abstract: The invention provides a decoder of symbols of received data, the data being encoded according to a convolutional encoding scheme and transmitted through a communications channel. The data is punctuated according to a puncturing matrix, and has a plurality of state values which describe a sequence of state transitions. The decoder has a generation unit that accepts the received data for calculating metrics of the transitions thereof. A selector responsive to the generation unit selects a path of transitions corresponding to the path produced by a transmitter of the data stream. A traceback unit maintains historical information representative of sequential decision operations of the selector. A counter is provided for counting illegal state transitions of the path selected by the selector, and a control unit, responsive to the counter, determines a puncture rate and adjusts a puncture phase of the received data.

Abstract: An MPEG video decompression method and apparatus utilizing a plurality of stages interconnected by a two-wire interface arranged as a pipeline processing machine. Control tokens and DATA Tokens pass over the single two-wire interface for carrying both control and data in token format. A token decode circuit is positioned in certain of the stages for recognizing certain of the tokens as control tokens pertinent to that stage and for passing unrecognized control tokens along the pipeline. Reconfiguration processing circuits are positioned in selected stages and are responsive to a recognized control token for reconfiguring such stage to handle an identified DATA Token. A wide variety of unique supporting subsystem circuitry and processing techniques are disclosed for implementing the system, including memory addressing, transforming data using a common processing block, time synchronization, asynchronous swing buffering, storing of video information, a parallel Huffman decoder, and the like.

Abstract: An optical drive system includes an optical assembly, a light source capable of transmitting light through the optical assembly, an objective lens positioned to direct light between the optical assembly and a respective information storage medium, and an actuator suspending the objective lens for relative motion thereof with respect to the actuator. A photodetector is disposed in a path of returning light to measure return light received from the respective medium. A monitoring circuit is provided to monitor a Quad Sum signal associated with the return light. A first servomotor is employed to move the objective lens in a tracking direction relative to the actuator and to move the objective lens during focus capture relative to the respective medium being read while system circuitry searches for a maximum Quad Sum signal. A second servo motor is employed to move the objective lens in a focusing direction relative to the actuator assembly.

Abstract: A CMOS integrated signal processing system for a sampling receiver includes a timing recovery circuit, wherein an on-chip numerically controlled oscillator is operative at periods T that are initially equal to the nominal baud rate of the signals controls a sinc interpolator receiving samples at the sampling rate. A loop filter is coupled to the sinc interpolator and to the numerically controlled oscillator. The arrangement is capable of handling various symbol rates. The system includes a circuit for carrier recovery having a second on-chip numerically controlled oscillator, a digital derotation circuit responsive to the second numerically controlled oscillator, accepting an in phase component and a quadrature component of the sampled signals. An adaptive phase error estimation circuit is coupled in a feedback loop.

Abstract: The invention provides a RAM interface for connecting a bus to RAM wherein a separate address generator generates the addresses the RAM interface needs to address the RAM. The interface utilizes a plurality of swing buffers, and has a control module for coordinating accesses thereto, which is connected to the address generator by a specialized two-wire interface. The address generator and the source of data are clocked asynchronously and at different clock rates.

Abstract: The mechanism for loading and unloading a disk cartridge uses two sliders (one on each side of a base plate), which move in opposite directions under the influence of a tiller. Each slider has a slot to receive one of the two lifting pins provided on the cartridge receiver. The movement of the sliders drives the lifting pins along the slots, thereby raising or lowering the cartridge receiver depending upon the direction of rotation of the tiller. The sliding motion of the lifting pins engaged in the S-shaped slots thus unloads a disk from or, alternatively, loads the disk onto the drive spindle. As the lifting pins travel along their respective slots, the lifting and lowering of the disk is accomplished in such a manner that the disk hub is peeled from the spindle magnet rather than being lifted vertically off the spindle. This reduces the peak force required to break the magnetic clamp force between the spindle magnet and the disk hub.

Abstract: An apparatus for controlling a magnetic field strength of a bias coil at a focal point of a lens during recording on a medium. The apparatus includes a first controller for determining a distance between the focal point of a lens and a reference point on the recording media. A source generates a stray magnetic field having a stray field strength at the focal point. A second controller calculates a digital signal which is a function of the distance and the stray field strength. A digital-to-analog converter converts the digital signal to a driver voltage and passes the driver voltage to a current driver, which drives the bias coil. The magnetic field strength of the bias coil is thereby controlled at a predetermined value.

Abstract: There is disclosed a method for moving an optical head from an initial track to a target track on a storage medium. The total number of tracks to be crossed is determined, and the optical head is moved toward the target track. A reflectivity level of light from the storage medium is measured, and a tracking error signal is derived from the reflectivity level. The tracking error signal has both true and false indicators of track crossings. A data indicator signal is derived from the reflectivity level, having indicator points corresponding to the false indicators of track crossings. A track count number is incremented for each true indicator of a track crossing, and the optical head is stopped when the track count number equals the total number of tracks to be crossed. Another method is disclosed whereby a track count signal is generated from the tracking error signal and the data indicator signal.

Abstract: An integrated digital communication system utilizing multilevel vestigial sideband transmission is provided. The communication system receives a multi-level pulse-amplitude modulated digital signal from a limited bandwidth channel. The system includes processing stages which demodulate, sample and filter the incoming signal prior to recovery of the digital data. Other stages recover the timing and lock on to the frequency and phase of the transmitted signal, as well as provide for automatic gain control. An adaptive equalizer, error correction circuitry, and an output interface recover the digital data and provide for transfer to other devices.

Abstract: A bias coil assembly for use in combination with a magnetomotive generator such as employed in a magneto-optical disc drive. The assembly includes a return yoke having a body portion and a tip having a predetermined thickness and extending beyond the body portion. A winding for receiving electric current is wound around the body portion of the yoke so that the winding is contained below the tip. A first plate is disposed on the winding and includes at least one heat-radiating finger extending substantially around the winding without increasing the vertical height of the assembly. A second plate is disposed on the winding in a magnetic circuit with the first plate and the return yoke so that when the winding is connected to a source of power, the tip receives lines of magnetic flux that are channeled through the body portion while the at least one flange radiates thermal energy thereby produced.

Abstract: A method and apparatus for manufacturing information storage devices is described herein. Two embodiments of the invention are disclosed. In particular, the invention includes, but is not limited to, a bearing insertion device, a lens insertion device, a coarse coil gluing tool, a spring gluing tool, a device for gluing pole pieces, a pentaprism insertion and inspection tool, a constants and transfers test, an optics module alignment device, wedge, microprism and beamsplitter insertion devices, a read channel alignment test, a mass balance attachment invention, a position sensor alignment tool, an invention for the attachment of focus and radial coils, a quality control test for test an optical storage device prior to insertion of the objective lens, and a servo system test. The invention described herein is designed to manufacture information storage devices with increased quality and efficiency.