Hughes Aircraft Company

John J Ferrer

Mao-Jin J Chern

Ronald George Hegg

Ronald T Smith

Lacy G Cook

Steven A Stringfellow

Gaylord E Moss

Michael N Ernstoff

William R Lichty

Brian D Cohn

Daniel M Battista

Harry J King

Martin Weinhrauch

Alan J Reuter

Matthew J Van Leeuwen

William J Wainwright

Paul C Norton

Robert D Williams

A low cost, compact projection display source that serves as a very bright image source for an automotive head up display. The present invention is comprised of a high intensity halogen light source and a liquid crystal display. The liquid crystal display is controlled by display electronics that write images onto the liquid crystal display that are to be displayed to the driver or passengers of a vehicle. Light output from the high intensity light source is transmitted through a piece of infrared energy absorbing glass, a decentered lens, such as a Fresnel lens, and a diffuser that uniformly backlights the liquid crystal display. Crossed polarizers are used on either side of the liquid crystal display. The high intensity light output transmitted by the liquid crystal display is passed through a yellow-orange output window which is projected onto a toric combiner for display to the driver of the vehicle. A fan provides cooling for the liquid crystal display and display circuitry that interfaces between the display electronics and the liquid crystal display. The projection display source produces a very high contrast (very bright) image source without heat problems. The projection display source is capable of producing 20,000 foot-lamberts of light energy output. The projection display source is the brightest known image source for non-military head up displays of either the non-reconfigurable or reconfigurable variety. The yellow-orange color used for the output window of the projection display source is used to maximize color contrast with the display background.

Head up display with a lens decentered to the optical axis of the

A compact, inexpensive and mass-producible optical display system for an automobile creates a highly visible and sharp, high contrast and pleasing, multi-color magnified virtual image of a primary instrument cluster at a viewing distance which is greater than the actual optical distance between the dashboard and the driver's eyes in order to enhance instrument readability, minimize driver eye strain, and reduce eye focus problems which are associated with transitioning between the far range viewing used for watching the road ahead and the near range viewing used for glancing at the instruments. A non-pupil forming display system uses a single off-axis aspherical mirror with power to create a virtual image of a miniaturized, multi-color passive image source, such as a segmented LCD panel, which is backlighted by a small filament incandescent light bulb. The aspheric surface is optimized to minimize aberrations and reduce vertical disparity and field curvature. The image source is pre-distorted to compensate for distortion in the off-axis configuration. A holographic diffusing screen element laminated onto the image source provides uniform high brightness and uniform contrast over the entire field-of-view which is visible from an eyellipse sufficient to accomodate most of the driver population, minimizes the visual impact of any optical aberrations near the edge of the viewing area, and provides the non-pupil forming system with some of the desirable optical properties of a pupil forming system.

Automotive instrument virtual image display

A helmet mounted display uses a see-through visor holographic combiner to provide, in the normal field of view of a helicopter pilot, a pair of images derived from an image source such as a miniature cathode ray tube. A source of the video display may be an infrared sensor mounted on an external turret underneath the helicopter. The turret rotates in response to helmet movements so that the pilot is continually provided with a dual image from the CRT display which corresponds with the external scene as visible through the visor.

Biocular holographic helmet mounted display

A head-up instrument display for a vehicle including a light emitting image source for producing imaging illumination and a combiner including a spherical beam-splitter coating for partially reflecting the imaging illumination to produce a virtual image viewable by the vehicle operator without diverting attention from the outside scene. In one embodiment, the head-up instrument display is self-contained with the combiner being rotatable into a stowed position when not in use.

Aircraft head-up display

A vehicle head-up instrument display including a light emitting image source for producing imaging illumination, optical apparatus for directing the imaging illumination to the inside surface of a vehicle windshield, and a combiner comprising a portion of the windshield or a coating applied to the windshield partially reflects the imaging illumination to produce a virtual image viewable by the driver. The image source and optical apparatus are enclosed in a housing having an elliptical cylindrical transparent cover for transmitting the imaging illumination to the windshield and for directing sunlight and skylight reflections therefrom away from the driver's eyes.

Automotive head-up display

An improved optical combiner useful in many applications is disclosed. The combiner includes a substrate with at least one aspheric surface and an diffraction-type reflective coating formed on the substrate for selectively reflecting radiation within one or more predetermined narrow band ranges of wavelengths impinging on the coating. The aspericity of the surface may be selected to compensate or balance optical aberations. The coating is advantageously a graded-index coating, which eliminates the possible degradation of gelatin halogram coatings due to moisture. A process for applying the graded-index coating to a substrate is disclosed. The variation in the index profile of the coating can be selected to provide the capability of combiners with multiple color reflectivity responses, or which allow use of display light sources of wider spectral bandwidth, resulting in a brighter image and improved angular bandwidth. In another disclosed embodiment, the combiner is incorporated in a biocular helmet visor display resulting in improved optical performance and a simpler, lightweight structure. In another embodiment, the combiner is incorporated into a head-up display for an aircraft resulting in improved performance, lower weight, improved safety and greater look-up capability.

Graded index asperhic combiners and display system utilizing same

An integrated head-up and panel display system for aircraft cockpits and the like is disclosed. The system utilizes a wavelength-sensitive fold mirror to separate the HUD image and the panel images. The system includes a monochromatic HUD image source for projecting the HUD image toward the fold mirror, and at least one panel display image source for projecting panel imagery toward the fold mirror. The transmission function of the fold mirror is notched at the wavelength of the monochromatic HUD image source. Thus, the fold mirror reflects the HUD image in the direction of the HUD optical combiner which reflects the HUD image to the system exit pupil. The fold mirror is adapted to transmit light in the visible spectra outside the narrow bandwidth of the HUD image source, so that the panel image is transmitted through the fold mirror to a look-down display screen assembly. The screen assembly may be a diffusion screen for providing an image plane at the screen, or an assembly of optical elements for providing a panel image superimposed at the system exit pupil.

Integrated head-up and panel display unit

A mounting and stowage mechanism erects a head-up display combiner into the pilot's line-of-sight. One end of a crank is mounted on the combiner and is pivoted on a first link which is pivoted to a frame. A support link is pivoted on the combiner and on a drag link which is pivoted to the frame. A connecting link is pivoted to both the first link and the outer pivot of the drag link to complete a compound 4-bar linkage which controls the path of the combiner between the erected position and a stowed position out of the pilot's line-of-sight. Manual control is through a handle which is mounted on a slider for linear motion and is connected to the end of the crank remote from the combiner. The mechanism is rendered insensitive to motion in the combiner-erect position by assuring that the instant centers of the links carrying the combiner are located at twice the focal length from the combiner along a line that runs through the center of curvature of the combiner and its focal point. The mechanism thus reduces optical errors caused by play or vibration in the mechanism.

Combiner mounting and stowage mechanism

A diffraction grating head up display is disclosed which blocks solar radiation from impinging upon and washing out the image of display information on an optical display device. This is accomplished by means of a filter such an optical element made of photochromic material which is positioned between the display information surface and relay optics lenses, preferably at the back focal plane thereof, so that focused solar radiation darkens a localized spot in the photochromic material. The darkened spot blocks the solar energy but reversibly lightens after the focused solar energy is removed. This photochromic material allows substantially unimpeded transmittance of the image of the display information except at the darkened spot. Also included in the optical system are a folding reflector and a combiner lens element which combines and superimposes the image of the display information on the scene being viewed when an observer looks through the combiner element. This combiner element is a diffraction grating holographic lens which is reflective or diffractive of a narrow bandwidth of light which includes the narrow bandwidth light of the display information.

Diffraction head up display solar radiation filter

There is disclosed a liquid crystal image projector which is suitable for use as an image source in an aircraft head-up display system. In this application, the projector provides extremely bright and high contrast symbology for the aircraft pilot. More generally, the projector has application wherever a television-type raster and/or calligraphic symbology display is needed. The increase in brightness and contrast ratio is achieved by using a reflector to concentrate light from a light source onto the liquid crystal display cell from whence it is reflected through an optical aperture stop in the reflector to the projecting lens and thence to a viewing surface.

Growing community of inventors

Los Angeles, CA, United States of America

John J Ferrer