Abstract: Apparatus and method for mitigating impedance changes in a microactuator conductive joint. In accordance with some embodiments, a microactuating element has a conductive input junction, the junction having dissimilar metals in contact with one another. The microactuating element is adapted to mechanically deform to displace a control object responsive to a micractuation control signal that is applied to the junction. A control circuit applies a bi-directional transition signal to the conductive input junction to reduce an increased impedance of the junction.

Abstract: The present invention is a method and system for reducing miscorrections of data in a post-processor. In an embodiment of the invention, the system and method may compare a result of an exact match function and a metric for each row of a reconstructed data block to determine if a correction should be made. An algorithm for performing an exact match function may include a column parity check syndrome, a matched filter error syndrome, and an error mask of the present invention. If a result of an exact match function is an exact match, a priority of correction may be given to the row in which the exact match was produced.

Abstract: An apparatus comprising a sampler circuit and a filter circuit. The sampler circuit may be configured to generate a digital signal in response to a pre-amplified signal. The filter circuit may be configured to generate a track ID signal in response to the digital signal. The filter circuit may also be configured to (i) improve or increase signal-to-noise ratio (SNR) and (ii) reject DC offset errors.

Abstract: An order in which bits for serial data are transmitted or received by a first device, integrated circuit (IC) or logic, is programmable to be either from most significant bit (MSB) to least significant bit (LSB) or from LSB to MSB. Therefore, when the first device is used with a second device, integrated circuit (IC) or logic, which can handle the serial data in only one order, the first device is programmed, or configured, to handle the serial data in the same order as the second device.

Abstract: The present invention is a method and system for reducing miscorrections of data in a post-processor. In an embodiment of the invention, the system and method may compare a result of an exact match function and a metric for each row of a reconstructed data block to determine if a correction should be made. An algorithm for performing an exact match function may include a column parity check syndrome, a matched filter error syndrome, and an error mask of the present invention. If a result of an exact match function is an exact match, a priority of correction may be given to the row in which the exact match was produced.

Abstract: A circuit generally comprising a first circuit and a phase lock loop. The first circuit may be configured to (i) collect a plurality of samples per cycle during a plurality of cycles of an input signal and (ii) calculate a phase offset and a frequency offset for the input signal relative to a clock signal in response to the samples. The phase lock loop may be configured to (i) preset a phase error signal to the phase offset and a frequency error signal to the frequency offset and (ii) generate the clock signal in response to the phase error signal and the frequency error signal.

Abstract: An optical disc system for storing information on a medium includes a light source, a focusing mechanism, and a tracking mechanism wherein the mechanisms are controlled by a feedback loop and the focusing mechanism focuses light emitted by the light source onto the medium to effect writing of information thereon. The system is provided with an electronic circuit for generating a servo error signal that is communicated in the feedback loop for effecting corrections of the focusing mechanism and the tracking mechanism. The system is further provided with a driver for energizing the light source, a bias coil disposed proximate to the medium, a bias coil driver switchably connected to the bias coil for supplying an electric current thereto, a current monitoring circuit connected to the bias coil driver having an output responsive to the electric current, and a controller connected to the output of the current monitoring circuit and to the driver.

Abstract: An analog to digital circuit assembly includes a circuit for multiplexing a reference voltage input of an analog to digital converter to produce alternating normalized and referenced digital outputs of an analog signal input at a rate controlled by a sampling clock which includes a switch including first and second inputs, an output, and a control input for alternately connecting the first and the second inputs to the output, the output being applied to the reference voltage input. An information detection device having a detection output and a servo mechanism that controls operations on detected information is provided in conjunction with a signal summing circuit, a direct current voltage reference, a control clock connected, a servo error signal circuit having a servo error signal output and input, a sampling clock, and a processing circuit having an input connected to a digital output of the analog to digital converter and an output for controlling the servo mechanism.

Abstract: An optical drive system includes a computer that monitors the current in an improved bias coil assembly in conjunction with a magnetomotive field generator to determine when a predetermined current threshold is exceeded. The bias coil assembly includes a wire coil wrapped around a center bar contained by a bias coil housing. The bias coil assembly is positionable above an information storage medium so that the entire medium may be within the magnetic field thereby allowing writing of information to all portions of the medium. When the threshold is exceeded, a sufficiently strong magnetic field is generated to permit writing of information on the storage medium utilizing a laser. A laser pulse generator is then enabled. The device thereby achieves a substantially shortened write cycle while employing the improved bias coil assembly.

Abstract: An optical drive system includes a computer that monitors the current in the bias coil of a magnetomotive field generator to determine when a predetermined current threshold is exceeded. When the threshold is exceeded, a sufficiently strong magnetic field is generated to permit writing of information on a storage medium utilizing a laser. A laser pulse generator is then enabled. The system is provided with an optics module for processing light produced by the laser light source. A laser driver for energizing the laser light source is positioned in close proximity to the optics module and the laser light source to reduce noise in signals associated with the optics module. The system thereby achieves a substantially shortened write cycle while reducing relevant signal noise.

Abstract: An analog to digital circuit assembly for use in an optical information includes a circuit for multiplexing a reference voltage input of an analog to digital converter to produce alternating normalized and referenced digital outputs of a plurality of analog signal inputs at a rate controlled by a sampling clock which includes a switch including first and second inputs, an output, and a control input for alternately connecting the first and the second inputs to the output, the output being applied to the reference voltage input.

Abstract: An optical drive system includes an optical assembly, a light source, a lens positioned to direct light between the optical assembly and an information storage medium or disc, and an actuator suspending the lens. A photodetector is disposed in a path of returning light to measure light received from the medium. A monitoring circuit is provided to monitor a Quad Sum signal associated with return light. A first servomotor is employed to move the lens in a tracking direction and to move the lens during focus capture while system circuitry searches for a maximum Quad Sum signal. A second servomotor is employed to move the lens in a focusing direction. A first electronic circuit is provided to control the first and second servomotors.

Abstract: A magneto-optical drive system having a computer that monitors the current in the bias coil of a magnetomotive field generator to determine when a predetermined current threshold is exceeded. When the threshold is exceeded, a sufficiently strong magnetic field is generated to permit writing of information on a storage medium utilizing a laser. A laser pulse generator is then enabled. The device thereby achieves a substantially shortened write cycle.

Abstract: A method and apparatus provides an improved optical storage disk player. An improved method and apparatus for obtaining a tracking error signal for an optical disk player is disclosed which is general across the various data formats found in CD audio disks, CD-ROMs, and digital video disks. The present invention uses a photodetector with at least four active areas to sense the reflected laser beam. A differential amplitude tracking error signal is generated by comparing the signal strength in the different active areas.

Abstract: A mechanical isolation apparatus suited for mitigating the effects of undesired mechanical forces upon disc drive system components, such as those found in compact disc, laser disc, magneto-optical player/recorder devices and similar devices. Component members are provided for mitigating the effects of compressive forces, vibration isolation, and thermal expansion, and may include compression ribs mounted on a housing for absorbing compressive forces. The housing is preferably adapted to fit on the end of a pole piece assembly. A crash stop may also be provided as a shock absorbing bumper and isolator to prevent a moving carriage from crashing into a solid surface. The compressive ribs and the crash stop are made of a material that exhibits minimum creep, such as a silicon rubber, polyurethane, or injection molded plastic.

Abstract: An optical disc drive apparatus includes mechanics, optics, electronic circuitry, and software code for implementing a method of disc rotation. One such method includes the changing of the rotational rate of a storage medium by applying a force to the storage medium to change the rotational rate from an initial rotational rate toward a first upper limit. The first upper limit is between the initial rotational rate and a desired rotational rate. A first signal is generated when the rotational rate exceeds the first upper limit. A second signal is generated when the rotational rate exceeds a lower acceptable limit of the desired rotational rate. The application of force is then terminated. To terminate the application of force, a second upper limit may be set at an upper acceptable limit of the desired rotational rate, a lower limit may be set at the lower acceptable limit of the desired rotational rate, and the application of force may be terminated when the rotational rate is greater than the lower limit.

Abstract: A system for focus capture wherein a lens is initially retracted to the bottom of its stroke, moved up to the top of its stroke while looking for the maximum Quad Sum signal, then moved back away from the disc while the system looks for the total light coming back from the disc to be above one-half of the peak value it measured, searching for the first zero crossing and, after the Quad Sum is over one-half amplitude, closing focus.

Abstract: An optical disc drive system is employed in conjunction with a storage medium having a plurality of data sectors each provided with a header and a data storage area. The system includes a data detection device for retrieving stored data from the storage medium and outputting a data signal, an amplifier for providing a variable gain to the data signal and outputting an amplified data signal, a detector that is responsive to the amplified data signal for evaluating a predetermined one of the sectors to ascertain whether the storage area is blank, and an automatic gain control circuit producing a gain control output for controlling the gain of the amplifier. The control circuit has a first mode and a second mode, the first mode being active during retrieval of the header and the second mode being active during retrieval of the data storage area.

Abstract: An optical drive system includes an objective lens subassembly for directing light from a light source toward an information storage medium. An amount of the directed lighted light is returned from the storage medium. An objective lens is disposed in the objective lens subassembly. A first servomotor moves, during focus capture, the objective lens to a first position, away from the first position toward the storage medium being read while looking for a maximum Quad Sum signal, and back away from the storage medium. An electronic control circuit is connected to the first servomotor. A servo error detector is coupled to the electronic control circuit and disposed in a path of light returning from the information storage medium.

Abstract: An improved method for operating an optical disc system having a focusing mechanism, a tracking mechanism, and a lens. The method includes the steps of impinging light upon a disc to be read, moving the lens to a first position by driving an actuator, monitoring a Quad Sum signal, moving the lens away from the first position toward the disc being read while looking for a maximum of the Quad sum signal, moving the lens away from the disc, determining, during the monitoring, when Quad Sum signal is above one-half the maximum, processing a focus error signal in a digital processing circuit having a transfer function providing a frequency notch at a mechanical resonance of the actuator. The digital processing circuit produces zero crossings corresponding to focus conditions method further includes searching for a first of the zero crossings after the Quad sum signal exceeds the one-half of the maximum, and closing focus when the first zero crossing is detected.