Discovision Associates

Leonardus I Grassens

David L Schell

Kurt W Getreuer

David E Lewis

Marvin B Davis

Hollis O'Neal Hall

Randolph Scott Crupper

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

An apparatus is described for aligning an actuator lens of an optical disk drive or the like within a baseplate assembly. The apparatus comprises 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 comprising 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 baseplate alignment may further comprise means for determining the lateral alignment of the beam with respect to the tower assembly and a plurality of lateral actuators for aligning the beam laterally with respect to the tower assembly. The tower assembly comprises 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. The gripper assembly comprises an objective lens assembly, an objective lens mounted to the objective lens assembly, an objective lens alignment assembly for aligning the objective lens with respect to the tower assembly and the cradle assembly, and an actuator lens tilt assembly for aligning the actuator lens with respect to the tower assembly and the cradle assembly.

Method and apparatus for aligning an objective lens

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Monument, CO, United States of America

Leonardus I Grassens