Discovision Associates

Applied Magnetics, LLC

Other

Leonardus J Grassens

Kurt W Getreuer

David L Schell

David E Lewis

Marvin B Davis

Randolph Scott Crupper

Hollis O'Neal Hall

Douglas E Hoover

Kent Thomas Murphy

Wilhelm Taylor

Russell A Meyer

James K Louie

Zdenek A Hollen

Charles DePuy

Gary Anderson

David L Papiernik

Christopher A Knorr

Herbert E Heaton

Christopher J Monsen

Robert G Russell

An apparatus for optical reading or recording information on an optical disc is rotatable about an axis of rotation. The apparatus includes a carriage, an objective lens, and an objective lens holder. The carriage has a center of mass. The carriage is movable relative to a frame along a path radial to the axis of rotation. The objective lens has an optical axis. The object lens is mounted to the objective holder so that the optical axis of the objective lens is within a first distance of intersecting the center of mass of the carriage. The holder is movable relative to the carriage so as to move the objective lens along its optical axis.

Optical actuator assembly with lens position sensor for recording or playback

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

An apparatus for optically reading or recording information on an optical disc which is rotatable about an axis of rotation. The apparatus includes a frame, a carriage, a carriage drive, an objective lens, an objective lens holder, a focus drive, a fine tracking drive and an objective lens position sensor. The objective lens is mounted on the objective lens holder so that the optical axis of the objective lens substantially intersects the center of mass of the carriage. The fine motor, used for tracking and focus, has a center of mass that substantially lies on the optical axis and proximate the center of mass of the carriage.

Optical actuator including lens assembly with optical axis having

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

An apparatus for aligning an actuator lens within a baseplate using a beam of radiant energy. The actuator lens has an actuator optical axis and an actuator optical center and the apparatus includes a frame, a cradle, a tower assembly, a lever assembly, and a gripper assembly. The cradle assembly is employed to hold the baseplate and is mounted to the frame with at least one degree of freedom of motion. The tower assembly defines a tower axis and is also mounted to the frame. The cradle and tower assemblies are positioned to receive the beam of radiant energy along the tower axis and analyze a spot profile of the beam. The lever assembly is rotatably mounted to the frame and the gripper assembly is mounted to the lever assembly.

Method and apparatus for aligning an objective lens

An apparatus for optically reading or recording information on an optical disc which is rotatable about an axis of rotation. The apparatus includes a frame, a carriage movable relative to the frame along a path orthogonal to the axis of rotation, and a carriage drive for driving the carriage along the orthogonal path. Specific portions of the carriage drive are mounted on the carriage so that the carriage and the mounted portions define a center of carriage mass. An objective lens having an optical axis along a Z-axis and a center of lens mass is provided in an objective lens holder. The holder is movable relative to the carriage and receives a beam of light traveling along an X-axis. Flexures are provided for movably supporting the objective lens holder relative to the carriage. The flexures each have a hinge point within an XZ plane so that movement of the lens holder is provided by hinge action at the hinge points. A focus drive is provided for driving the lens holder which moves the objective lens along its optical axis. The focus drive and the objective lens holder define a center of fine motor mass. The center of fine motor mass, the center of carriage mass, and the center of lens mass are substantially coincident on the optical axis so that when the objective lens holder is moved in a tracking direction, moments about the Z-axis are minimized.

Seek actuator for optical recording

An apparatus for focusing an actuator lens within an optical disc carriage held by a baseplate assembly. The apparatus incudes a frame, a cradle assembly mounted to the frame, 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, a member for determining the tilt alignment of the beam with respect to the tower assembly, and 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 representation of a beam of radiant energy passing through the tower magnifying lens and into the video camera. A method for focusing an objective lens includes the steps of placing a lens in the carriage, directing a beam of radiant energy through the objective lens onto the optical disc, and aligning the beam with respect to the optical disc while maintaining the optical center of the objective lens at a predetermined intersecting point. A return beam of radiant energy is reflected from the optical disc and the spot profile of the return beam is analyzed. The objective lens is moved toward or away from the optical disc using a focus actuator until the analyzer indicates that the beam is in proper focus.

Method and apparatus for focusing a lens

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. A method for mounting a lens is described which includes the steps of placing a lens in the carriage, aligning the lens by moving a baseplate assembly with respect to the tower assembly, moving the objective lens assembly with respect to the tower assembly, and moving the actuator lens with respect to the tower assembly. The lens is attached to the gripper assembly and the lever moves the gripper and lens away from the carriage. Adhesive is applied to the carriage and the lever is moved back so as to place the lens on the adhesive in the aligned position.

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

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.

Method and apparatus for manufacturing information storage devices

An apparatus for optically reading or recording information on an optical disc which is rotatable about an axis of rotation. The apparatus includes a frame, a carriage, a carriage drive, an objective lens, an objective lens holder, a focus drive and a fine tracking drive. The objective lens is mounted on the objective lens holder so that the optical axis of the objective lens substantially intersects the center of mass of the carriage. The fine motor, used for tracking and focus, has a center of mass that substantially lies on the optical axis and proximate the center of mass of the carriage.

A device for reading information from or writing information to an optical disc memory system using light from a laser diode includes an upper and lower flexure suspension. Both flexure suspensions are mounted on both an objective lens holder and its base. Each of these flexures is U-shaped and the central part of each leg of the U is a stiff beam. At each end of the control beam is provided a tracking hinge. Outward from the tracking hinges are a pair of focusing hinges which are separated from the tracking hinges by means of spacing beam sections. The unique configuration of the system allows these parallel mounted flexures to move in only two rigid modes namely, displacement along the x-axis (tracking) and displacement along the z-axis (focusing). These two rigid modes allow the objective lens to be re-positioned so that light beams may strike the information medium correctly. The sturdiness of these beam section therefore constrains the four remaining degrees of freedom so that displacement in the y direction, namely tangential motion and rotation in the x, y and z directions, specifically roll, pitch and yaw are severely limited thus essentially eliminated. This feature is paramount in that the possibilities . for undesired skewing of the flexure and the attached objective lens are precluded.

Flexure suspension for two axis actuator

The present invention is an apparatus for optical reading or recording information on an optical information medium, wherein as a result of the relative position of the components of the apparatus and the magnitude and application points of the forces exerted to track and focus, the objective lens through which information is read from the information medium, prevents the objective lens from being affected by most resonances, motor forces and reaction forces. This is critical in that in optical recording, displacements of 0.02 micrometers can easily be picked up. Specifically, one aspect of the invention is an apparatus for optically reading or recording information on an optical disk which is rotatable about an axis of rotation, wherein the apparatus includes a frame, a carriage, a carriage drive, an objective lens, an objective lens holder and a focus drive. The carriage drive (i.e., those portions of the carriage motor which move relative the frame) drives the carriage along a path radial to the axis of the rotation. The objective lens is mounted on the objective lens holder so that the optical axis of the objective lens is within 0.5 millimeters of intersecting the center of mass of the carriage mass. The holder is movable relative to the carriage so as to move the objective lens along its optical axis. This movement is controlled by a focus drive (i.e., those portions of the focus motor which move relative to the carriage) which drives the holder so as to move the objective lens along its optical axis. For purposes of this application including appended claims, the carriage and actuator assembly is considered to be broken down into two mass groupings. The first is the 'fine motor mass' (i.e., the mass of all components suspended for freedom of movement from the carriage). The second is the 'carriage mass' (i.e., the mass of all components which move with the carriage excluding the fine motor mass and any incidental connecting wiring not wholly supported by the carriage).

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Monument, CO, United States of America

Leonardus J Grassens