Digilens Inc.

Sbg Labs, Inc.

John James Storey

Milan Momcilo Popovich

Jonathan David Waldern

C David Nabors

Michael R Adams

Mark Purser

An Electrically Switchable Bragg Grating (ESBG) despeckler device comprising at least one ESBG element recorded in a hPDLC sandwiched between transparent substrates to which transparent conductive coatings have been applied. At least one of said coatings is patterned to provide a two-dimensional array of independently switchable ESBG pixels. Each ESBG pixel has a first unique speckle state under said first applied voltage and a second unique speckle state under said second applied voltage.

Laser illumination device

An apparatus for recording a holographic device comprises: a master hologram comprising a multiplicity of holographic elements each characterized by one of a predefined set of grating prescriptions; a transparent substrate supporting a layer of holographic material; and a light source. Each holographic element diffracts source light onto a predefined region of the layer. Each prescription modulates at least one of phase, amplitude, and angle of the light. There is further provided a method of recording a holographic device, comprising the steps of: providing said apparatus; exposing the master to illumination from the source; and diffracting light from each holographic element onto a predefined region of the layer.

Optical apparatus for recording a holographic device and method of recording

An internal device having a lightguide which cooperates with an internal light source. A first light coupling element couples an external light source to the lightguide and a second light coupling element extracts the total internal reflection (TIR) from the lightguide. Between the first and second lightguides, an angular grating device and phase grating device are imposed. The angular grating device applies angular diversity to the rays of the TIR light, while the phase grating device applies phase diversity to the rays of the TIR light. Each of the grating devices has a plurality of electrically switchable grating pixels having a unique first and second diffracting state which varies based on the applied voltage.

Disclosed is an apparatus and method of illuminating an image display via an electrically switchable holographic optical element. The method includes a first electrically switchable holographic optical element (ESHOE) receiving illumination light. The first ESHOE comprises oppositely facing front and back surfaces. The first ESHOE focuses a first component (e.g., p-polarized blue light) of the illumination light while transmitting the remaining components of the illumination light without substantial alteration. An image display is provided and receives the focused first component. In response to receiving the focused first component, the image display emits image light. The first ESHOE receives and transmits this image light without substantial alteration. In one embodiment, the focused first component emerges from the first ESHOE at the back surface thereof, and the first ESHOE receives the image light at the back surface.

Holographic illumination system

Disclosed is an illumination system using optical feedback to maintain a predetermined illumination output. The illumination system employs an electrically controllable optical filter for filtering light incident thereon. The illumination system also includes a light detector for detecting at least a portion of the light filtered by the electrically controllable optical filter. The light detector is in data communication with the electrically controllable optical filter. Some or all light filtered by the electrically controllable optical filter is detected by the light detector, which, in turn generates a corresponding signal that is compared to at least one predetermined value. If the signal generated by the light detector differs when compared to the at least one predetermined value, one or more filtering characteristics of electrically controllable optical filter are varied which, in turn, varies the amount of light filtered by the electrically controllable optical filter. The filtering characteristics of the electrically controllable optical filter continue to be varied until the signal generated by the light etector substantially matches the at least one predetermined value.

Illumination system using optical feedback

Method of and apparatus for viewing an image

Disclosed is a method for calculating relative phase between channels of a multi-sensor tracking device. The relative phases may be used to calibrate the multi-tracking sensor device to perform more accurately. The method involves recording a plurality of first signals generated by a first channel of the multi-sensor tracking device. The plurality of first signals are generated during a movement of the multi-sensor tracking device. Typically, the multi-sensor tracking device includes several channels, each one of which includes at least one sensor for sensing movement with respect to a corresponding axis. Concurrent to recording of plurality of first signals, a plurality of second signals generated by a second channel of the multi-sensor tracking device, is recorded. The plurality of second signals are generated during the movement of the multi-sensor tracking device. Thereafter, a relative phase between the first and second channels is calculated as a function of the recorded plurality of first signals and the recorded plurality of second signals.

Method for calculating relative phases between signal channels in a multi-sensor tracking device

Disclosed is an apparatus and method of illuminating an image display via an electrically switchable holographic optical element. The method includes a first electrically switchable holographic optical element (ESHOE) receiving illumination light. The first ESHOE comprises oppositely facing front and back surfaces. The first ESHOE diffracts a first component (e.g., p-polarized blue light) of the illumination light while transmitting the remaining components of the illumination light without substantial alteration. An image display is provided and receives the diffracted first component. In response to receiving the diffracted first component, the image display emits image light. The first ESHOE receives and transmits this image light without substantial alteration. In one embodiment, the diffracted first component emerges from the first ESHOE at the back surface thereof, and the first ESHOE receives the image light at the back surface thereof so that the image light is received by the first ESHOE in a direction substantially parallel to a direction at which the diffracted first component emerges from the back surface of the first ESHOE.

A method of managing latency in a system for tracking movement of an object includes providing a request-and-response mechanism for transferring tracking data across a communications link. In one embodiment, the object for which movement is to be tracked is a human head and the system is a virtual reality system. Packets of the tracking data may be generated using a conventional sensor processing technology, but the packets are transferred via the communications link to an image processing capability, such as that of a host computer. The packets are generated at a fixed sample rate that is asynchronous with respect to the processing requirements of the host computer. When the host computer is available for fresh tracking data, a packet-transfer request is transmitted to the source of the packet. Latency can be reduced by enabling the source of the packets to anticipate reception of a packet-transfer request. Thus, any incoming signal to the source is &ldquo;prematurely&rdquo; interpreted as a packet-transfer request. Appropriate actions are executed, if the interpretation is subsequently determined to be inaccurate. As a technique for reducing variability of latency, each transfer of a packet is preceded by a determination of whether to transmit a presently available packet or a next available packet. If a request is received momentarily before the next available packet is accessible, the presently available packet may be identified as &ldquo;stale,&rdquo; and the next packet may be transmitted when available.

Request-and-respond approach to reducing latency within a tracking system

Holographic optical elements (HOEs) can be used in systems and methods for providing illumination and for projecting images. The HOEs may be switchable HOEs, whose diffractive properties can be controlled. Described herein is a method of combining light from two or more illumination sources. In one embodiment, a reflection-type HOE is illuminated by the first illumination source. The HOE diffracts light from the first illumination source into an output direction. Light from the second illumination source is transmitted through the HOE and onto a reflective optical element, which reflects the light back through the HOE and into the same output direction. Also described is a projection system that uses two or more HOEs to combine two or more colors of light for use by a single image display. The system includes one or more light sources, an image display (such as a reflective or transmissive LCD display or a MEMS display, for example), and a first and a second HOE. The HOEs are each mounted between a light source and the image display, and configured to provide one color of light to the image display and from the image display into an output direction. In one embodiment, the HOEs are switchable HOEs and can be used for color-sequential display and/or for color balancing.

Growing community of inventors

Wallaton Nottingham, United Kingdom

John James Storey