Discovision Associates

Laser Magnetic Storage International Company

Marvin B Davis

David L Schell

Kurt W Getreuer

David E Lewis

Kent Thomas Murphy

Randolph Scott Crupper

Leonardus J Grassens

Christopher Anthony Pollard

Hendrikus W Peeters

Wilhelm Taylor

Michael V Konshak

Leonardus I Grassens

Clay E Gaetje

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. The analog to digital circuit assembly is also implemented in an optical disc system for improved operation thereof.

Analog to digital converter assembly for normalizing servo error signals and multiplexing reference voltage inputs and digital outputs and improved optical drive system including same

A cartridge unloading apparatus for a disk drive having a cartridge loading end, a remote end, and a base plate. The apparatus is employed for tiltably unloading the disk from a spindle magnet with a peeling action. The apparatus includes first and second sliders positioned relative the ends of the disk drive. The sliders each have only one S-shaped slot formed therein. Each slider has a slot to receive one of the two lifting pins provided on a 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. The apparatus may include a bias coil assembly rotatably mounted on an arm so that the bias coil assembly may be loaded into or extracted from the disk cartridge and placed out of the travel path of the disk cartridge. Methods for manufacturing and operating the apparatus in conjunction with a disk drive are also provided.

Cartridge loading apparatus and methods of manufacturing and operating same

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. An information detection device having multiple detection outputs and having at least one servo mechanism that controls operations on information being detected 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 multiple inputs, 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 at the least one servo mechanism.

Analog to digital converter and assembly for use in optical drive system to normalize servo error signals and multiplex reference voltage inputs and digital outputs

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. A servo error circuit is coupled to the first electronic circuit and the photodetector to determine when return light exceeds a predetermined value, to search for a first zero crossing, and to indicate to the first electronic circuit to close focus by the second servomotor when the Quad Sum signal exceeds a predetermined amplitude. A focus capture method for use in the system includes impinging light upon the disc, moving the lens, monitoring the Quad Sum signal, moving the lens while looking for a maximum Quad Sum signal, monitoring light received from the disc, determining when the light is above a measured peak value, searching for the first zero crossing, determining when the Quad Sum signal exceeds a predetermined amplitude, and closing focus at the predetermined amplitude.

Optical disc system having servo motor and servo error detection assembly operated relative to monitored quad sum signal and focus capture method for use in same

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. In this system, the dust door is attached to the cartridge receiver, and the label end of the loaded cartridge remains visible when the disk is loaded. This system may include a bias coil assembly rotatably mounted on an arm so that the bias coil assembly may be loaded into or extracted from the disk cartridge and placed out of the travel path of the disk cartridge. The rotation of the bias coil arm is effected by one of the sliders.

Cartridge-loading apparatus with tilting bias coil assembly

A releasable disc adaptor for conforming the central hub of an information storage disc to a standardized magneto-optical disc drive spindle. The disc adaptor includes a hub receiving member having a center connected to a medium receiving member having a center. The centers of the medium receiving and hub receiving members are collinear. The adaptor includes a hub fastener fixedly mounted to the hub receiving member. The hub fastener is utilized to removably secure the hub receiving member to a disc drive spindle. The adaptor also includes a medium fastener connected to the medium receiving member. The medium fastener is used to removably secure the central hub of an information storage disc to the hub receiving member and prevent slippage therebetween so that the disc hub is thereby conformed to properly seat on the disc drive spindle while thereafter allowing the disc to be fully disengaged from the adaptor members for proper seating on an alternate disc drive spindle. The hub receiving member, medium receiving member, hub fastener, and medium fastener form a portable assembly that may be employed in any one of a plurality of magneto-optical disc drives.

Releasable disc adaptor for conforming central hub of information

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.

Isolation apparatus for use in disc drive system to mitigate effects of

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. The servo error detector is implemented to determine when total light returned from the information storage medium exceeds a predetermined value, to search for a first zero crossing, corresponding to when the Quad Sum signal exceeds a predetermined amplitude, and to indicate to the electronic control circuit to direct close of focus when the Quad Sum signal exceeds the predetermined amplitude.

Optical drive system having servomotor operated relative to maximum quad

Cartridge-loading apparatus with improved base plate and cartridge

An apparatus for the suppression of electromagnetic emissions from an electronic device. The apparatus includes a die cast metallic container having a continuous wall, a shoulder formed on the continuous wall, a plurality of rounded corners, and a neck portion. The neck portion and shoulder mate with a deep drawn metallic cap. A source of electromagnetic emissions is disposed in the interior space defined by the container and the cap, and a flex strip source passes through a groove formed in an external wall of the container to supply the source. The container is adapted for use in an optical disc system and provides a mount for a semiconductor laser modulated at a radio frequency on the order of 450 MHz. The container also holds auxiliary electronics. A conductive tape seals the assembly so that electromagnetic emissions of the laser are confined within the interior space.

Apparatus and method for suppression of electromagnetic emissions having

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. A first electronic circuit is provided to control the first and second servomotors. A servo error circuit is coupled to the first electronic circuit and the photodetector to determine when the return light exceeds a predetermined value, to search for a first zero crossing determining when the Quad Sum signal exceeds a predetermined amplitude, and to indicate to the first electronic circuit to direct close of focus by the second servomotor when the Quad Sum signal exceeds the predetermined amplitude.

Optical disc system having servo motor and servo error detection

Disk drive system having improved cartridge-loading apparatus including

Cartridge-loading apparatus with improved cartridge receiver

Cartridge-loading apparatus with improved parking arm

A disk cartridge having a housing in which a disk is rotatably mounted via a hub assembly. The housing includes two cover plates, each of which has a door aperture that is selectively covered by a door that is controlled by a dedicated door control assembly. When the cartridge is inserted into a disk drive, each door is opened by its respective door opening assembly such that both sides of the disk are accessible for magnetic or optical read/write operations. In the preferred embodiment, the hub assembly includes two hub halves, at least one of which includes a plurality of resilient fingers for leveling a surface of the disk when the cartridge is contained within the disk drive. At least one of the hub halves also includes a channel having a plurality of pockets formed therein such that when a spindle base having a torque transferring element is positioned adjacent to the pockets, one of the pockets is able to substantially immediately receive the torque transferring element.

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Colorado Springs, CO, United States of America

Marvin B Davis