Hughes Aircraft Company

Hughes-jvc Technology Corporation

Victor Company of Japan, Limited

Stephen J Reinsch

William P Bleha

Barney J Kaelin

Joseph Hubert Colles

Paul F Robusto

Nobuo J Koda

David D Scofield

Stephen J Purdy

Harry W Giehll

Joseph M Haggerty

Byung S Hong

An image projection system is provided for generating an energy efficient output representative of a desired input image. The image projection system includes a light source positioning device for directing the light from a light source onto a spatial light modulator. An image source provides the desired image to the spatial light modulator and also image information to a light source position controller for coordinating the light source positioning device, such that the light from the light source impinges substantially only the area of the spatial light modulator which contains the desired image. In particular, the controller actuates the light source positioning device by using a predefined scan that corresponds to the desired image. The spatial light modulator modulates the light with the desired input image and generates an output representative of the desired image. A beam brush may also be used for changing the width of the projection beam from light source, thereby improving image resolution and maximizing energy conservation.

Laser imaging using a spatial light modulator

A projection system includes first and second light valve projectors which project a composite image onto a screen by overlapping the first and second images in an overlap region. Each projector includes a light source, a light valve for reflecting or transmitting image light, a condensing lens for directing light from the light source to the light valve, and a projection lens. An improved light valve projector includes a blending device, associated with the first and second light valve projectors and being located in the path of the light between the light valve and the projection lens, the light source and the condensing lens, or the projection lens and the screen. The blending device smoothes off-state and on-state illumination levels in the overlap region without reducing the contrast ratio of said light valve projector. The blending device includes physical devices such as filters, solid masks, and/or a combination thereof as a substitute for electronic blending. By physically blending off-state illumination levels, the present invention avoids loss of contrast ratio associated with electronic blending.

Projected image blending for multiple images

A high contrast polarizer and color beam splitter for use in a full color light valve projector includes a light source for providing input light on a first optical axis and first, second and third light valves for modulating light of first, second and third colors. The polarizer and color beam splitter includes a color and angle sensitive interface, located on the first optical axis, for reflecting at least part of the input light. A polarizer, located on a second optical axis, receives the input light reflected by the color and angle sensitive interface and reflects light of a first polarization along the second optical axis. A first color separator, located on the second optical axis at a first angle with respect to a plane orthogonal to the second optical axis, reflects light of the first color onto the color and angle sensitive interface. The color and angle sensitive interface transmits the light of the first polarization and the first color, received from the first color separating means, onto the first light valve. The polarizer and color beam splitter minimizes the angle of the first color separator to decrease the phase change and increase contrast while maintaining a compact size.

High contrast, compact, full-color polarizer and color beam splitter

A polarized light optimization system for increasing the percentage of usable light for image projector illumination purposes. The system includes a light source, and a beam splitter that splits randomly polarized light from the light source into first and second beams having first and second polarizations. A polarization converter or rotator converts the polarization of one of the beams into the polarization of the other beam. Recombination means recombines the beams into a singularly polarized third beam, thereby increasing system illumination by increasing the percentage of usable light output from the light source. The recombination means includes a sawtooth mirror that has a plurality of substantially parallel equiangular mirrored facets that reflect incident light in a manner that maintains a radiation angle of divergence identical to that of the input randomly polarized light beam, thereby maintaining a maximum light contrast as the polarized beam is transmitted through the projector prism onto a projector light valve.

Sawtooth interleave polarization combiner

A liquid crystal light valve (12) is sequentially modulated with images corresponding to three primary color components of a scene at a rate which is faster than flicker can be perceived. A color switching apparatus (20) receives a white light beam from a high intensity light source (18), separates the white light beam into three color light beams of the respective primary colors, and sequentially illuminates the light valve (12) with the three color light beams in synchronism with modulation of the light valve (12) with the corresponding color image components. An optical system (26) projects an image of the modulated light valve surface on a screen (28), such that the three color component images appear to merge together in time and thereby synthesize a full color image of the scene. The switching apparatus (20) includes a polarizing beam splitter (30), three dichroic reflectors (34,36,46) which separate the white light beam into the three color light beams, and electrically switchable polarization rotators (38,40,48). The rotators (36,40,48), in combination with the beam splitter (30), control the polarizations of the color light beams such that only a selected one of the beams is directed to an output with a predetermined polarization suitable for illumination of the light valve (12), and the other two colors are effectively switched off.

Color switching apparatus for liquid crystal light valve projector

A hand held instrument for measuring roughness of a surface, such as 'orange peel', on a painted surface employs a scanning disc (58) which mounts a unique unfocused light source (60) to project a diverging light beam (12,68) at the surface (14,54) in a circular scan pattern. Light (16) reflected from the surface is received by a sensor (18,80) which produces an output electrical signal (20) having an amplitude and frequency that follow the amplitude and frequency of reflected light received by the sensor. Electrical signals representing amplitude (32) and frequency (36) are suitably combined (38) to provide an output display (40) of magnitude of orange peel. A point light source (106-116) is provided by removing part of the integral lens (108) of a conventional light emitting diode and roughening the surface (112) exposed by removal of the lens to provide a diffusing exit window for the diode. A plate (114) having an aperture (116) smaller than the size of the light emitting chip (96) of the diode is placed on the roughened surface and a lens (130) is employed to control divergence of light from the point source so as to provide an unfocused, slightly diverging light beam (134).

Optical monitoring

A hand held instrument for measuring roughness of a surface, such as the 'orange peel' on a painted surface, employs a scanning disc (42) which mounts a light source (56) to project a light beam at the surface being measured in a circular scan pattern. Light reflected from the surface is received by a sensor (90) which produces an output electrical signal having an amplitude and frequency that follow the amplitude and frequency of reflected light received by the sensor. Electrical signals representing amplitude and frequency are suitably combined (134) to provide an output display (114) that reads the value of orange peel according to a set of values determined by calibration of the instrument from a set of calibration panels.

Hand held paint inspection meter

A focus coil (20) is adjustably retained around the neck (12c) of a cathode ray tube (12) inside a shield (14). An alignment apparatus (62) includes a ring (64) which is movable with five degrees of freedom and clamps onto the coil (20) through holes (14j) formed through the shield (14). The tube (12) and shield (14) are held stationary, while the ring (64) and thereby the coil (20) are moved to align the coil (20) relative to the tube (12) in accordance with electrical alignment test signals applied to the tube (12). A clam shell (66) which is generally coaxially disposed between the shield (14) and ring (64) includes a plurality of arcuate segments (66a) which are hinged together at their ends, and have pins (66b) extending radially inwardly therefrom for clamping engagement with the coil (20). A screw (70) extends inwardly from the ring (64) to clamp the clam shell (66) between its inner end and a radially opposed portion (72) of the inner surface of the ring (64). A sleeve (40) removably fixes the coil (20) to the neck (12c) of the tube (12), and includes a plurality of resilient fingers (56) which are movable into and out of locking engagement with the neck (12c). The sleeve (40) is clamped to the neck (12c) and, after alignment of the coil (20) to the tube (12), the coil (20) is fixed to the sleeve (40) using an adhesive.

Cathode ray tube focus coil alignment and assembly arrangement

A compact, full color, light projection system using a liquid crystal light valve (LCLV) and a unique combination of optical devices. The LCLV operates to modulate a light beam which has been polarized by one of the optical devices. The modulated light beam is converged and registered by other optical devices to form the output image.

Liquid crystal light value color projector

An air flow sensor 14 senses the presence of cooling air from a blower 12 to a lamp housing 10. A vane 44 closes an opening 42 when air is flowing to close a switch 50 which permits a lamp 16 to be turned on. The vane 44 does not extend into the air flow path.

Air flow sensor

An improved optical block for use in a high brightness, full color image projection system of the type wherein high intensity (acrhomatic) projection light is modulated by a full color image composed of a plurality of monochromatic images applied to a plurality of polarization modulating light valves. A polarizer accepts the achromatic, unpolarized output of a high intensity source. Light of a preferred polarization orientation emergent therefrom is directed by the polarizer to a two level array of polarization-sensitive dichroic filters and wavelength-tuned biprisms. Input level dichroic filters separate the incoming unmodulated light into a plurality of component wavelength bands and direct each to a wavelength-tuned biprism. Each biprism directs the selected bandwidth of polarized light to the reflective surface of a light valve. Light reflected therefrom is altered in polarization in the presence of the chromatic component of the full color image and passes to the second or output level of the optical block. Polarization selective dichroic filters in the output level combine the polarization-modulated chromatic components into a high brightness, full color modulated image and direct the image to projection optics.

Growing community of inventors

Vista, CA, United States of America

Stephen J Reinsch