Discovision Associates

Applied Magnetics, LLC

Inphase Technologies, Inc.

O. R. Technology, Inc.

Sanyo Electric Co., Ltd.

Magnetic Peripherals Inc.

Tamarack Storage Devices

Nphase Technologies, Inc.

Curtis A Shuman

Mark R Ayres

Keith W Malang

Larry Fabiny

Ivan Prikryl

Stephen W Farnsworth

Jan Hoogland

David M Perry

Jahja I Trisnadi

Charles Henry Ernst

Peter Joseph Van Laanen

Steven L Grove

Hollis O'Neal Hall, Ii

James Patrick Rice

In one aspect of the present invention, a device for sensing an absolute position of an encoded object, comprising: a position tracking module comprising: a track illumination module configured to illuminate the encoded object with one more light beams, and to detect one or more light beams resulting from said illumination of said encoded object; and an absolute position determinator configured to determine the absolute position of the encoded object based on said one or more light beams resulting from said illumination of said encoded object.

Sensing absolute position of an encoded object

Disclosed are optical systems and methods of producing obliquity corrected light beams, for example, holographic recording and retrieval systems that utilize an obliquity corrected reference beam. One method includes directing a light beam reflected from a prism mirror to a reference plane with an angle of incidence to the reference plane, wherein the prism mirror varies the width of the light beam according to the angle of incidence to the reference plane. The optical system may include a holographic data storage system and the reference plane may be associated with a holographic storage medium.

Obliquity correction scanning using a prism mirror

Disclosed are methods of producing obliquity corrected light beams, and holographic recording and retrieval systems that utilize a obliquity corrected reference beam. The obliquity correction is accomplished using off-center lenses.

Obliquity correction system

Disclosed are apodizers and methods for redistributing the intensity of a light beam. Particularly, single component apodizers are disclosed. The single component apodizers include a single lens component that is capable of redistributing the intensity of a coherent light beam.

Single component aspheric apodizer

In an optical positioning system, a holographic optical element having a plurality of rectangular apertures has predetermined ones of its aperture edges castellated or notched in order to null out undesired light energy in target areas. The apertures may be fitted with diffraction grating patterns that may also be castellated for the same purpose. A method of using the aperture and grating pattern castellated holographic optical element is also provided.

Holographic optical element with castellated aperture

A position sensor and a method of creating the same which sensor has an incoherent light source, multiple light detectors and a sinusoidal pattern that can be directly installed to the sensor. The light source and detectors are positioned along the axis of motion of the element whose position is to be determined. In a device containing such a movable target element, light from the sensor is directed through the sinusoidal pattern to and reflected from a periodic reflection profile to create detectable sinusoid signals that can be used for positioning purposes.

System and method for creating and utilizing a sinusoidal based pattern

An optical beamsplitter comprises a right angle prism having a hypotenuse and two legs wherein the hypotenuse includes an optically selective coating deposited thereon. An optical element is positioned adjacent the hypotenuse such that the hypotenuse and the optical element form a beamsplitting interface. Various optical elements are utilized to achieve the desired spatial and angular relationships between incoming and outgoing light beams. Several embodiments are disclosed wherein the optical element can comprise a flat plate for providing spatial offset, a wedged plate for producing spatial and angular offset, a lens for adding optical power, or a faceted thin plate.

Optical beamsplitter

A holographic storage system and method are provided in which a light source (12) is used to generate a coherent light beam which is split into a reference beam (18) and an object beam (20). The reference beam (18) is directed to the holographic storage medium (22) through use of a reference beam multiplexer (24). The object beam is encoded with a pattern encoder (34) and directed to the holographic storage medium (26). During read out, the object beam is reconstructed and detected by an optical detector (40).

Method and apparatus for azimuthal multiplexing of holograms

A compact optical head for reading or writing data on an optical disc is disclosed wherein the optical head comprises an integrated laser diode/photodetector package, a half-cube beamsplitter, and an objective lens. Light emitted from a diode laser is in transmitted to the beamsplitter and deflected towards the objective lens. The objective lens focuses the incident light on a focal point on the surface of the disc. A reflected beam travels along the same path as the incident light and is deflected by the beamsplitter toward a photodetector contained in the integrated package, wherein the photodetector is displaced from the laser diode. Other embodiments of the beamsplitter are disclosed which include a wedged plate for transmitting collimated light emitted from the laser diode, and a cylindrical lens for introducing astigmatism into the reflected beam. The present invention provides a substantial reduction in the size and volume required by the optical head, advantageously allowing the head to be easily integrated with an actuator for focussing and tracking the incident beam on the disc.

Compact optical head

An apparatus for evaluation of radiation beam geometry that finds application in determining the focus of an illuminating beam relative to an optical disk is disclosed herein. In one preferred embodiment, a light source generates a linearly polarized beam which is collimated by a collimating lens. The collimated beam is then converged by an objective lens onto the surface of the optical disk. The disk reflects the illuminating beam focused thereon back through the objective lens to a beam splitter. A portion of the optical energy incident on the beam splitter is then redirected to form a servo beam, wherein the degree of collimation of the servo beam is indicative of the focus position of the illuminating beam. A beam separation module, based on frustrated total reflection, having a reflectivity which varies in response to the angle of incidence of optical energy thereon is positioned to intercept the servo beam. The beam separation module is operative to separate the servo beam into transmitted and reflected beams of substantially similar shape and intensity. Electrical signals produced by photodetective elements in response to incidence of the transmitted and reflected beams thereon may then be used to generate a focus error signal.

Focus sensing apparatus utilizing a reflecting surface having variable

A multi-element, air-spaced prism system for use in a reflective-type optical media device having a light source to provide an incident light beam provides an achromatic, anamorphic prism which corrects for astigmatism and ellipticity in the light beam from the light source. One embodiment of the prism system provides at least two reflections of a return beam from the reflective-type optical media. The return prism provides these reflections from various optical surfaces in the multi-element prism system. In one embodiment, the prism system also provides a reflection of a portion of the incident beam. This reflection is directed to a detector which can, for instance, monitor the intensity of the light beam.

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Colorado Springs, CO, United States of America

Curtis A Shuman