Patents by Inventor Marvin B. Davis

Marvin B. Davis has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6418097
    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.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: July 9, 2002
    Assignee: Discovision Associates
    Inventors: David L. Schell, Randolph Scott Crupper, Kurt W. Getreuer, Leonardus I. Grassens, David E. Lewis, Marvin B. Davis
  • Patent number: 6411584
    Abstract: 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.
    Type: Grant
    Filed: February 19, 1999
    Date of Patent: June 25, 2002
    Assignee: Discovision Associates
    Inventors: Marvin B. Davis, Kent T. Murphy
  • Publication number: 20010043544
    Abstract: 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.
    Type: Application
    Filed: February 19, 1999
    Publication date: November 22, 2001
    Inventors: MARVIN B. DAVIS, KENT MURPHY
  • Patent number: 6266306
    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.
    Type: Grant
    Filed: October 9, 1997
    Date of Patent: July 24, 2001
    Assignee: Discovision Associates
    Inventors: David L. Schell, Randolph Scott Crupper, Kurt W. Getreuer, Leonardus J. Grassens, David E. Lewis, Marvin B. Davis
  • Patent number: 6243336
    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.
    Type: Grant
    Filed: March 16, 1998
    Date of Patent: June 5, 2001
    Assignee: Discovision Associates
    Inventors: David L. Schell, Randolph S. Crupper, Marvin B. Davis, Kurt W. Getreuer, Leonardus J. Grassens, David E. Lewis
  • Patent number: 6201659
    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.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 13, 2001
    Assignee: Discovision Associates
    Inventors: Marvin B. Davis, Kent Murphy
  • Patent number: 6167023
    Abstract: 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.
    Type: Grant
    Filed: May 1, 1997
    Date of Patent: December 26, 2000
    Assignee: Discovision Associates
    Inventors: Marvin B. Davis, Clay E. Gaetje
  • Patent number: 6122232
    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.
    Type: Grant
    Filed: January 20, 1998
    Date of Patent: September 19, 2000
    Assignee: Discovision Associates
    Inventors: David L. Schell, Randolph S. Crupper, Marvin B. Davis, Kurt W. Getreuer, Leonardus J. Grassens, David E. Lewis
  • Patent number: 6058081
    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.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: May 2, 2000
    Assignee: Discovision Associates
    Inventors: David L. Schell, Randolph Scott Crupper, Kurt W. Getreuer, Leonardus J. Grassens, David E. Lewis, Marvin B. Davis
  • Patent number: 6009061
    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.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: December 28, 1999
    Assignee: Discovision Associates
    Inventors: Marvin B. Davis, Kent Murphy
  • Patent number: 5920539
    Abstract: 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.
    Type: Grant
    Filed: April 11, 1995
    Date of Patent: July 6, 1999
    Assignee: Discovision Associates
    Inventors: David L. Schell, Marvin B. Davis
  • Patent number: 5729511
    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.
    Type: Grant
    Filed: January 25, 1995
    Date of Patent: March 17, 1998
    Assignee: Discovision Associates
    Inventors: David L. Schell, Randolph S. Crupper, Marvin B. Davis, Kurt W. Getreuer, Leonardus J. Grassens, David E. Lewis
  • Patent number: 5724331
    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.
    Type: Grant
    Filed: August 25, 1994
    Date of Patent: March 3, 1998
    Assignee: Discovision Associates
    Inventors: Marvin B. Davis, Kent Murphy
  • Patent number: 5703857
    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.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 30, 1997
    Assignee: Discovision Associates
    Inventors: Marvin B. Davis, Kent Murphy
  • Patent number: 5684776
    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.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 4, 1997
    Assignee: Discovision Associates
    Inventors: Marvin B. Davis, Kent Murphy
  • Patent number: 5060106
    Abstract: 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.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: October 22, 1991
    Assignee: Laser Magnetic Storage International Company
    Inventors: Marvin B. Davis, Hendrikus W. C. M. Peeters, Wilhelm Taylor
  • Patent number: 4823214
    Abstract: A disk drive includes a drive mechanism for engaging the disk of a disk cartridge. A support is provided to move the drive mechanism into engagement with the disk. Several alternative supports are disclosed, employing cam mechanisms to pivotally move the drive mechanism. Also, pins are provided to restrain the cartridge housing from movement while the support is operated. An actuator is provided to open the cartridge as it is inserted into the drive.
    Type: Grant
    Filed: November 19, 1987
    Date of Patent: April 18, 1989
    Assignee: Laser Magnetic Storage International Company
    Inventor: Marvin B. Davis
  • Patent number: 4791511
    Abstract: A disk cartridge for a disk drive has a slide door normally biased to the closed position. A recess on the door is positioned laterally offset from the horizontal center as to be oriented in either the upper or lower portion of the door depending on the orientation of the cartridge housing. The recess is engagable by a door opening mechanism on the disk drive to move the door to its open position wherein the disk media is exposed to the sensors in the disk drive. The recess is engagable by the door opening mechanism regardless of the orientation of the cartridge. A lock button supported on a resilient support engages the door recess when the door is in its closed position to thereby lock the door; the door opening mechanism engaging the lock button to unlock the door when engaging the recess.
    Type: Grant
    Filed: August 22, 1986
    Date of Patent: December 13, 1988
    Assignee: Laser Magnetic Storage International Company
    Inventor: Marvin B. Davis
  • Patent number: 4745500
    Abstract: A disk drive includes a drive mechanism for engaging the disk of a disk cartridge. A support is provided to move the drive mechanism into engagement with the disk. Several alternative supports are disclosed, employing cam mechanisms to pivotally move the drive mechanism. Also pins are provided to restrain the cartridge housing from movement while the support is operated. An actuator is provided to open the cartridge as it is inserted into the drive.
    Type: Grant
    Filed: September 19, 1985
    Date of Patent: May 17, 1988
    Assignee: Laser Magnetic Storage International Company
    Inventor: Marvin B. Davis
  • Patent number: 4740949
    Abstract: An apparatus is disclosed for providing laser access to an optical disk enclosed in a cartridge when the cartridge is loaded into an optical drive. Two opposed panels, mounted slidably to the cartridge casing, are spring biased to close an access window in the casing. Each panel includes a detent accessible from outside of the cartridge. In the optical drive is a platform that receives and guides the cartridge as it is inserted into the drive. Two spring-loaded links are mounted relative to the platform. As the disk is inserted into the drive, the detents engage their corresponding links. Responsive to further cartridge insertion, each of the links pivots to move its associated panel to an open position against the spring biasing force.
    Type: Grant
    Filed: April 16, 1987
    Date of Patent: April 26, 1988
    Assignee: Laser Magnetic Storage International Company
    Inventor: Marvin B. Davis