Texas Instruments Corporation

Stephen Wesley Marshall

Robert J Gove

Donald B Doherty

Richard C Meyer

Vishal Markandey

Scott D Heimbuch

Jeffrey Brian Sampsell

James C Dunphy

Steven Monroe Penn

Todd Alan Clatanoff

Paul M Urbanus

Carl W Davis

Gary L Sextro

Joseph G Egan

Bill C McDonald

Michael M Allbright

Venkat V Easwar

David Mehrl

Frank Joseph Poradish

Austin L Huang

Donald Andrew Powell

Henry William Neal

Harold E Bellis, Ii

Roger S Carver

Mark L Burton

John R Reder

William M Bommersbach

Getzel Gonzalez Garcia

Michael David McCormick

James Andrew DeLong

William R Breithaupt

Andrea C Harriman

Stanford Porter Hudson

Frederick C Wedemeier

Donald L Hicks

Jefferey B Sampsell

Girault W Jones, Jr

Roger P Perry

Donald C Whitney

According to one embodiment, a method of increasing a perceived resolution of a display includes directing light at a optical dithering element and repeatedly transitioning the optical dithering element from a first position to a second position and then back to the first position such that the mirror alternately reflects light to a first position on the display and then to a second position on the display. Each transition of the mirror includes controlling any overshoot or ringing in the position of the optical dithering element by providing a predetermined drive signal to the optical dithering element to smoothly accelerate and decelerate the element during the traverse between the first and second positions.

Method and apparatus for increasing a perceived resolution of a display

The disclosure provides an apparatus for reducing speckle in a projection visual display (PVD) system, a method of reducing visible speckle in a PVD system and a PVD system incorporating the method or apparatus. In one embodiment, the apparatus includes a diffuser interposable in an optical path of a PVD system and a diffuser actuator having a single drive axis configured to cause the diffuser to travel in a Lissajous curve at least partially transverse to the optical path.

System and method for reducing visible speckle in a projection visual display system

In one embodiment, a display device includes a movably suspended diffuser screen, and a voice-coil mechanism coupled to the diffuser screen. A signal-processing device, such as a microprocessor, is coupled to a driver circuit to produce a drive signal at an output terminal for the voice coil in response to a voltage sensed across the voice coil. The driver circuit includes shutdown control to drive its output terminal to a high-impedance state to accommodate sensing voltage across the voice coil. Thus, the signal for the voice coil is produced by the signal-processing device in a closed-loop feedback arrangement without the need for separate position-sensing elements. In a preferred arrangement, a second voice coil is coupled to the diffuser screen and to the signal-processing circuitry to produce a second signal for the second voice coil to accommodate generating a circular motion for the diffuser screen without stationary points.

Apparatus and method for using voice coils as screen motion sensors

Video signals in a video stream are encoded by inserting reference signals in the video stream such that the encoded video stream carry both reference signals and video signals being coded. In the decoding stage, reference images generated from the reference signals are detected and used for identifying the encoded video signals based upon the profiles of the detected reference images. An imaging architecture capable of using the coding scheme comprises a shutter that can be implemented as a dual-processor configuration.

Coding scheme for digital video signals and an image architecture using the same

In accordance with the teachings of the present disclosure, a system and method for displaying an image are provided. In one embodiment, the method includes receiving a laser through a rotary diffuser. The rotational speed of the rotary diffuser may be continuously varied to reduce the effect of an image artifact in a light pattern. The image artifact may be caused by an imperfection in the rotary diffuser. The light pattern is projected on a display device.

System and method for reducing the effect of an image artifact

The invention provides an apparatus for reducing speckle in a projection visual display (PVD) system, a method of reducing visible speckle in a PVD system and a PVD system incorporating the method or apparatus. In one embodiment, the apparatus includes a diffuser interposable in an optical path of a PVD system and a diffuser actuator having a single drive axis configured to cause the diffuser to travel in a lissajous curve at least partially transverse to the optical path.

According to one embodiment, a method for providing position feedback for a device includes providing a photointerrupter having a light-emitting diode, a phototransistor, and an aperture between the light-emitting diode and the phototransistor. For a given size aperture, a current through the phototransistor is a function of a current through the light-emitting diode. The method also includes controlling the current through the light-emitting diode current such that a change in the effective aperture size results in a desired approximately proportional change in current through the phototransistor. While controlling the current through the light-emitting diode, a portion of the aperture is blocked by an arm that has a position indicative of the position of the device. The method also includes providing a signal indicative of the change in current through the photodiode as an indication of the change in position of the device.

Method and apparatus for display

System and method for improving efficiency in driving LEDs. A preferred embodiment comprises a switch current regulator coupled to a current control signal input, the switch current regulator to control an amount of current provided to the LED based upon a magnitude of a voltage on the current control signal input, a switching voltage regulator coupled to the switch current regulator and the LED, the switching voltage regulator to provide current to the LED, and a sensor coupled to the switch current regulator, the LED, and a signal feedback circuit, the sensor to measure status information regarding the switch current regulator and the LED and provides the information to a controller, wherein the status information can be used to adjust the current on the current control signal input.

System and method for driving light-emitting diodes (LEDs)

An optical system for projecting an image having x and y axes onto a image plane is provided. The system includes an SLM device spaced from the image plane, the SLM device having a plurality of pixels operable to project pixels of the image onto the image plane and positioned such that the individual pixels of the projected image are oriented at substantially 45 degrees relative to the x and y axes of the image. The system further includes an optic element disposed between the SLM device and the image plane and a linear displacement device operatively connected to and operable to selectively displace at least one of the SLM device and the optic element. A method for projecting an image onto a image plane is also provided.

Optical system and method for increasing image resolution and/or dithering in projection applications

System and method for an optical position sensor architecture for use in servo systems. A preferred embodiment comprises a light source configured to produce a light with an intensity dependent upon a control signal, a first light sensor and a second light sensor positioned adjacent to one another, each light sensor configured to produce a current based upon an amount of light incident upon each light sensor. The preferred embodiment also comprises a slotted device coupled to the load and positioned between the light source and the first light sensor and the second light sensor. The slotted device regulates an amount of light striking the first light sensor and the second light sensor based upon a position of the load. The slotted device features a slot that has a radius with a linearly increasing radius as a function of rotation angle so that the optical position sensor has linear behavior.

Optical position sensor architecture for servo systems

According to one embodiment, a method for controlling positioning of an optical dithering element includes repeatedly driving the optical dithering element approximately between a plurality of desired positions by a generally periodic drive waveform. During a particular period of the drive waveform, the actual position of the optical dithering element is determined at a plurality of sample times. For each of the determined actual positions of the optical dithering element, a position error indicator is determined based upon whether the magnitude of the actual position is greater than, less than, or the same as a desired setpoint for the position of the optical dithering element. The method also includes generating an error signature for the particular period based on the determined error indicators and modifying the drive waveform in response to the error signature.

Apparatus for controlling the positioning of an optical dithering element

Method and apparatus for providing position feedback of an optical dithering element

A system and method for correcting non-periodic event time of arrival data in a control system. The system and methods are particularly applicable to the speed and phase control of a color wheel used with spatial light modulators. The circuitry automatically and accurately compensates for non-periodic index signals occurring when one or more index marks on the color wheel are misplaced. The system adds to or subtracts clock pulses from the actual time of arrival of a specific index mark until the corrected value equals the desired or nominal value. The system then generates a PWM signal for controlling the speed and phase of the color wheel.

Method to correct non-periodic index event time-of-arrival data in a synchronization system

Method and apparatus for controlling the positioning of an optical dithering element

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Richardson, TX, United States of America

Stephen Wesley Marshall