Hughes Aircraft Company

Minnesota Mining and Manufacturing Company

United States of America As Represented by the Secretary of the Air Force

Vivitek Co., Ltd.

Mao-Jin J Chern

Ronald George Hegg

Ronald T Smith

John J Ferrer

John E Wreede

Gaylord E Moss

Robert D Lowrey

Steven A Stringfellow

Lacy G Cook

Chungte W Chen

John E Gunther

John W Peters

Anson Y Au

Brian D Cohn

Brent Copely Frogget

Harry J King

Martin Weinhrauch

Matthew J Van Leeuwen

William J Wainwright

Teena L Dobbs

Paul C Norton

A virtual image display system with reduced ambient reflection. The virtual image display system includes a black and white image source for projecting a black and white image. The black and white image is then projected to a magnifying virtual image optical arrangement including a concave reflecting mirror. The magnifying virtual image optical arrangement and a color shutter including a linear polarizer receive the black and white image to generate a magnified color virtual image. The virtual color image display system further includes a .lambda./4-plate for cooperating with the color shutter including the linear polarizer to reduce an ambient reflection from the concave reflecting mirror.

Virtual image display system with reduced ambient reflection and low

A compact, inexpensive and mass-producible optical display system for an automobile creates a dramatic and highly stylistic, sharp, high contrast and pleasing, multi-color or monochromatic 3-D magnified image of an instrument cluster, at least a portion of the 3-D image being located at a viewing distance greater than the actual optical distance between the dashboard and the driver's eyes. A non-pupil forming display system uses an off-axis aspherical narrow-band reflecting mirror with power to create a magnified virtual image of a miniaturized passive image source, such as a segmented LCD panel, which is backlighted by a small filament incandescent light bulb. A single mirror produces a single monochromatic virtual image, whereas a plurality of stacked and differently curved mirrors, each tuned to different wavelength bandwidth, produces a plurality of spatially separated virtual images of differing colors. The mirrors are holographic optical elements or graded index optical elements. A backlit panel display positioned behind the mirror produces an image with colors outside the bandwidth of that mirror and thereby creates a secondary image of oversized warning indicators or the like visible in front of the virtual image which includes a display of other instruments. A non-planar image source used with the mirror produces a non-planar monochromatic virtual image.

Automotive instrument 3-D virtual image display

A virtual image display optical system. The system includes an image source, a combiner, and a relay group. The relay group is a catatrioptic relay group that includes a reflective optical element, and a refractive lens group that includes at least one doublet and a diffractive lens. For some applications, the catatrioptric relay group may be replaced by a hybrid refractive-diffractive relay group, thus eliminating the reflective element. The diffractive optical element of the hybrid optical element is encoded on one side of a lens. The hybrid optical element forms a refractive/diffractive achromat to provide for primary chromatic aberration correction. The refractive lens group is also an achromat to provide for chromatic aberration correction. Power distribution between the hybrid optical element and the refractive lens group is such that secondary chromatic aberration of the refractive lens group is balanced out by the secondary chromatic aberration of the hybrid optical element. The diffractive optical element is designed using higher order wavefront correction terms encoded on one side to reduce spherochromatism and secondary spherochromatism of the relay group. One lens may have a conic or an aspherical surface to further reduce the spherochromatism and secondary spherochromatism. Asymmetrical aberration and distortion resulting from the combiner are compensated for by the reflective optical element. To minimize the residual aberration of the optical system, the reflective optical element is tilted and/or decentered. The system has a relatively wide spectral bandwidth, has good image quality, has simple optics, is ultracompact, and provides wide field coverage and large field overlaying.

Wide spectral bandwidth virtual image display optical system

A focusable virtual image display system employing a focusable image source such as a cathode ray tube and imaging optics to provide a virtual image. The virtual image is viewable by a user and its effective range may be changed without changing the apparent field of view or resolution. By placing the focus point of the imaging optics at the design eye, the image source is moved backwards and forwards, thus effectively changing the range of the virtual image observed by the user without changing the apparent field of view or resolution. The present invention allows the user to adjust the focus position of the virtual image of the image source by moving it relative to the imaging optics, while maintaining the size and resolution of the image. If the user wants to move the image further away, when the image source is moved, the imaging optics moves the virtual image further away and magnifies the image such that the angular field of view stays the same. The user cannot distinguish between the sizes, although the focus will be more comfortable for a particular accommodation range. The relative cost of the virtual image display system is relatively less expensive than large screen monitors due to the nature and complexity of the smaller components. By including a focus adjustment mechanism, the focusable virtual image display monitor has an added feature that a conventional large screen monitor does not provide.

Virtual image display having a high efficiency grid beamsplitter

Focusable virtual image display

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 helicopter sight system including an illuminated reticle for controllably providing reticle imaging illumination and an active display for controllably providing active display illumination that contains alignment information provided by an electronic aiming system, the active display and the reticle being controlled to provide respective imaging illumination at different times. The reticle illumination and the active display illumination are directed by a color beam combiner along a common axis to a focussing lens system which illuminates a transparent combiner to produce a reticle image and an active display image viewable by the operator of the helicopter. The focussing lens system, the reticle, and the active display are configured so that the reticle image is positioned at optical infinity and the active display image is positioned at less than optical infinity, whereby the reticle image is positioned at a relatively long optical distance so that the focus of the reticle image sufficiently matches the relatively long distance to the target, and whereby the eyebox for viewing the active display image is larger than the eyebox for viewing the reticle image. More particularly, the reticle is positioned at a distance from the focussing lens system that is equal to the focal length of the focussing lens, and the active display is positioned at a distance from the focussing lens system that is less than the focal length of the focussing lens.

Reduced combiner helicopter sight system

A virtual image display for vehicles that includes a first image source for providing first imaging illumination, a second image source for providing second imaging illumination, a combiner responsive to the first and second imaging illumination for producing a combiner imaging illumination output, a negative power aspheric off-axis mirror responsive to the combiner imaging illumination output for providing diverging reflected imaging illumination, and a positive power aspheric off-axis mirror responsive to the diverging imaging illumination for providing converging reflected imaging illumination that produces a virtual image of the image source observable by the vehicle operator. By way of illustrative example, the first image source includes electromechanical gauges, and the second image source includes an alphanumeric display such as a liquid crystal display or a vacuum fluorescent display. The image sources can be selectively illuminated so as to display only one image source at a time, or they can be selectively illuminated so that components of the virtual image are produced by both of the image sources.

Two-page automotive virtual image display

A filter device 10 and method of making the same is disclosed. The device comprises holographic means 12 for diffracting optical radiation of a first predetermined range of wavelengths, and optical radiation filter means 14 for filtering optical radiation of a second predetermined range of wavelengths. The optical radiation filter means is coupled with the holographic means.

Filter device employing a holographic element

A head-up display having an image source for producing imaging illumination, an optical combiner for partially reflecting the imaging illumination to produce a virtual image of the image source that is viewable by the operator of the vehicle, and a polarizer which can be controllably interposed between the image source and the optical combiner for nighttime use. The polarizer tends to block the illumination that otherwise would produce objectionable ghost images.

Automotive head-up display with high brightness in daytime and high

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 plurality of reflective diffusing holographic memory elements (16) is positioned on a memory plate (14). An array (24) of detectors (22) faces at least one of the memory elements. A laser (26) illuminates the selected memory element and the data stored therein is reflected onto the array for reading. A new memory element may be illuminated or may be brought into interrogation position.

Holographic data storage and retrieval system

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.

Growing community of inventors

Rancho Palos Verdes, CA, United States of America

Mao-Jin J Chern