Abstract: In order to help maximize the capacity of an optical storage device, and increase the efficiency of addressing, a unique addressing scheme is utilized to provide addressing for an optical storage disk. Importantly, this scheme is compatible with multilayer disks and helps to minimize the potential for errors. In the addressing scheme of the present invention, the storage media is provided with a wobbled groove, which includes addressing information for the media. More specifically, the surface of the media is divided into predetermined sections, or portions, each portion having a selected number of wobble periods. Within these wobble periods, the amplitude of one single wobble period is either reduced or eliminated. The location of this reduced or eliminated wobble signal can then be determined by the readout system of the present invention and utilized to provide addressing information.

Abstract: An apparatus and method for moving a carriage assembly from an initial position to a target position relative to a storage medium rotating at a circumferential velocity. A processor determines a velocity trajectory relative to the radial distance of the initial position and the target position to the center of the medium, the circumferential distance between the initial position and the target position, and the initial circumferential velocity of the medium. The processor directs the drive to move the carriage assembly using the velocity trajectory so that the carriage assembly will arrive radially and circumferentially at the target position at substantially the same time. Additionally, the rotation of the storage medium may be changed from the initial circumferential velocity to a target circumferential velocity.

Abstract: A system and method for use in a data storage system which provides a combined phase lock loop (PLL) that utilizes a common Voltage Controlled Oscillator (VCO) and common integrator/loop-filter, but which is operational in a wobble-mode and a data-mode to provide most optimum operation and quick capture. Digital circuitry is primarily used in addition to the VCO and a loop-filter for acquiring frequency and phase lock while the optical disc drive is writing and reading. A digital Phase-detector for operation in the wobble-mode employs a down-counter that can be configured for both Frequency-Lock and Phase-Lock in a way that offers a large capture range and can adapt quickly to the multiple data-zones of the media-format.

Abstract: 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.

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 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: 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.

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 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 optical actuator adapted to control the position of the actuator in at least two degrees of freedom of motion. The actuator includes a base, a moveable lens holder having a lens, a structure for connecting the lens holder to the base to support movement of the lens holder, and first and second pairs of surface-field motors, each pair of surface-field motors having first and second surface-field motors, each first and second surface-field motor including a surface-field coil and a surface-field magnetic assembly for applying forces to the lens holder to move the lens holder in at least two degrees of freedom of motion relative to the base, the surface-field coil being mounted on either the base or the lens holder, and the corresponding surface-field magnetic assembly being oppositely mounted on either the lens holder or the base to interact with the surface-field coil.

Abstract: An apparatus for moving a carriage assembly from an initial position to a target position relative to a storage medium rotating at a circumferential velocity. The apparatus includes a suspended body having a center of mass and a lens defining an optical axis. The center of mass being disposed substantially on the optical axis. The carriage assembly suspends the suspended body and has a center of mass on the optical axis proximate the center of mass of the suspended body. A drive producing a plurality of balanced and symmetrical forces moves the carriage assembly from the initial position to the target position. A processor determines a velocity trajectory relative to the radial distance of the initial position and the target position to the center of the medium, the circumferential distance between the initial position and the target position, and the initial circumferential velocity of the medium.

Abstract: 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.

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 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 for moving a carriage assembly from an initial position to a target position relative to a storage medium rotating at a circumferential velocity. The method includes the steps of determining a first radial distance between the initial position and a center of the storage medium, determining a second radial distance between the target position and the center of the storage medium, determining a circumferential distance between the initial position and the target position, determining an initial circumferential velocity of the storage medium, calculating a velocity trajectory relative to the first radial distance, the second radial distance, the circumferential distance, and the initial circumferential velocity, and moving the carriage assembly from the initial position to the target position substantially at the velocity trajectory. The velocity trajectory is calculated such that the carriage assembly will arrive radially and circumferentially at the target position at substantially the same time.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An optical disc player/recorder incorporates a laser, and an electromagnetically driven objective lens. The objective lens is mounted to a lensholder which is movable with respect to a base. A single pair of permanent magnets are mounted to the lensholder, and two pair of electromagnetic coils are mounted to the base. The coils and magnets are positioned such that one set of coils is collinear with the direction of magnetization of the permanent magnets and the other set of coils is perpendicular to the direction of magnetization of the magnets. Electromagnetic fields generated by the coils are used to move the objective lens in either a focus direction or a tracking direction. The magnets are mounted on the moveable objective lensholder, while the coils are attached in a heat-sink relationship to the fitted base. The objective lens rests on top of the objective lensholder which is suspended with respect to the base by a pair of flexures.