Polaroid Corporation

Massachusetts Institute of Technology

Corporation for Laser Optics Research

Stephen A Benton

Ravikanth Pappu

Wendy J Plesniak

Joel S Kollin

Sabrina M Birner

Herbert S Mingace, Jr

Julie L Walker

William R Houde-Walter

A laser projection video system and a holographic screen. The system includes a pulsed laser video image system with a holographic screen to receive the full color video image, which screen has a holographic layer (layer ) to reflect back the full color video image to the viewer and to transmit through the screen the ambient light to provide high video picture contrast.

Video projection holographic screen, system and method

An autostereoscopic display system is capable of tracking one or more users within a viewing zone and presenting complementary stereoimages to each of the viewer's (or viewers') eyes. Polarization is used to segregate the images that are to be directed to different spatial regions. The two images are interdigitated within a single display&mdash;that is, each band of image points from the first image alternates with a band of image points from the second image on the display. The bands of the first image are polarized in a first mode and the bands of the second image are polarized in a second mode orthogonal to the first, e.g., through use of a liquid-crystal display (LCD) in which alternating, contiguous bands of pixels correspond to bands of one or the other image, and a &ldquo;patterned polarizer&rdquo; also organized into bands and aligned with the pixel bands. Autostereoscopic viewing is facilitated by a display (such as an LCD) that is illuminated by light from an outside source whose polarization can be controlled. Illumination from the light source passes through a focusing lens and then through the patterned polarizer and display so as to form a &ldquo;real&rdquo; or &ldquo;aerial&rdquo; image of the display in the viewing zone, with the different images directed to different regions of the viewing zone.

Autostereoscopic display system

A user is able to interact with and modify an electronic holographic image using a force-feedback (or haptic) device, which is capable of sensing and reporting the 3D position of its hand-held stylus and &ldquo;displaying&rdquo; appropriate forces to the user. Thus, a user can feel and modify specified shapes in the haptic workspace. The haptic workspace is precisely registered with the free-standing, spatial image displayed by a holographic video (holovideo) system. In the coincident visuo-haptic workspace, a user can see, feel, and interact with synthetic objects that exhibit many of the properties one expects of real ones, and the spatial display enables synthetic objects to become a part of the user's manipulatory space.

Dynamic holographic video with haptic interaction

A three dimensional display system includes a laser for generating a laser light signal. The signal is expanded and collimated using a traditional lens system and is directed to an acousto-optic modulator wherein it is modulated to generate a three dimensional image such as a holographic image. The modulation signal for the modulator is provided by a data processing system. The data processing system applies signals to the modulator that encode a diffraction pattern. The diffraction pattern is realized by the modulator upon application of the signals and the three dimensional image is produced by the modulated light signals. The image is demagnified by a demagnifier, and subsequently, imaged by a viewing lens. A horizontal scanner continuously multiplexes segments of the holographic image and compensates for the motion of segments across the modulator. A vertical scanner is provided to properly vertically position horizontal lines of the holographic image.

Three dimensional display system

A three-step process is combined with an edge-lit system to provide a self-contained, maximally-compact holographic display. In one embodiment, a hologram is affixed to an upstanding transparent support plate mounted through the top of a housing in which the hologram is edge-illuminated with white light from a source in the housing immediately beneath the plate to generate brilliant, sharp and deep multi-color images which straddle the hologram plane. In another embodiment, the transparent support plate is mounted in a frame which carries the edge-illumination source. All displays may either be free-standing or wall-mounted, as desired.

Self-contained compact multi-color edge-lit holographic display

Holographic color control systems are disclosed for the production of pseudocolor holograms by in-situ sequential swelling of an emulsion and exposure to three color separation images with a single wavelength reference light source. The resulting holograms yield images in three color primaries with excellent color registration and mixing, producing a full gamut of mixed colors, pastels and neutrals with three-dimensional perspective.

Holographic color control systems

Methods and devices for recording and projecting holographic stereograms are disclosed. In one aspect of the invention, a concave semi-cylindrical ('alcove') display system is disclosed in which an image is projected in front of the alcove. The display system provides a very wide angle of view approaching 180 degrees (compared to the 30 degrees of a typical flat hologram) that allows the viewer to look around most of the image content. This type of display is particularly useful in computer aided design projects where designers wish to present an overall three-dimensional display of their work. In another aspect of the invention, a holographic printer and procedures for recording a stereogram are disclosed as well as techniques for producing 'predistorted' images for the sub-holograms. A digital processing technique is disclosed which effectively predistorts the source two-dimensional image set for the stereogram to compensate for the effects of the display geometry. This predistortion technique relies upon anamorphic ray tracing. A crossed slit model for the holographic optical system is used to determine the direction and origin of the rays of light from which each sub-hologram of the stereogram is made.

Real image holographic stereograms

A method of producing achromatic holographic images of an object, and a diffraction grating useful for making an achromatic hologram. The method comprises the steps of making a monochromatic hologram on a first photographic plate, making a diffraction grating by exposing a second photographic plate to a series of colinear point sources of mutually coherent monochromatic light, developing and bleaching the exposed plate to produce the diffraction grating, making a second hologram by exposing a third photographic plate to an image from a narrow elongated strip of the first hologram with the diffraction grating in the optical path, and making an achromatic hologram by holographically recording the image produced by illuminating the second hologram with monochromatic light on a fourth photographic plate.

Method and apparatus for making achromatic holograms

Apparatus for illuminating transmission holograms from the rear with an illumination source located in front of the hologram, comprising a reflector and a light trap adapted to be mounted behind the hologram at a location chosen to reflect light from the source through the hologram as though from a source behind the hologram, while reflecting ambient light from the direction of an observer of the hologram into the trap.

Mirror-absorber for use in the illumination of transmission holograms

A method of making achromatic holographic stereograms in which projected images from a sequence of two-dimensional transparencies of a scene taken from a sequence of successively displaced positions are sequentially holographically recorded on adjacent strips of a photographic plate while the plate is inclined at an acute angle to the optical axis of projection of the images. The sequence of holographic strip images so recorded are re-recorded on a second hologram using a beam conjugate to the original reference beam to illuminate the strip hologram. The second holographic recording is done with the aid of a vertically inclined collimated reference beam of coherent light. Upon illumination of the second hologram with white light, a three-dimensional image of the original scene may be viewed by an appropriately placed observer which is achromatic over an extended angle of view and an extended apparent scene depth.

Holographic products and processes

Apparatus for viewing superposed stereographic images each presented in a different color, comprising a color television receiver having a dual dichroic polarizing filter over the viewing screen, and a pair of spectacles having orthogonally polarized lenses for viewing the screen through the filter.

Apparatus for viewing stereoscopic images

Reflection mount for transmission holograms

A process of making holographic images comprising the steps of recording a hologram of a parallax limited aerial image formed by a lens on a recording surface with a reference beam at an angle of incidence to the recording surface that is preferably equal and opposite to the angle of incidence of the object beam to the recording surface, and illuminating the hologram with a beam of diverging or collimated light, preferably at the angle of incidence of the object beam to the recording surface and directed oppositely to the direction of the object beam during recording. Illumination can be with white light. The hologram may comprise superposed recordings of the aerial image made with light of different wavelengths to produce full color holographic images.

Methods of making holographic images

Volume dielectric holograms are prepared by methods which have in common the intra-emulsion diffusion transfer of silver atoms within the emulsion by a process of dissolving undeveloped silver halide, and diffusing and precipitating said dissolved silver on precipitation sites provided by the development of the exposed silver halide. The resulting metallic silver is then rehalogenated to substantially reconstitute the original silver halide volume of the emulsion.

Production of volume dielectric holograms

A holographic arrangement is provided with light filtering means for transmitting only those light rays to the hologram which are incident to the hologram at the prescribed angles required for substantial diffraction while at the same time operating to preclude the transmission of other light rays to the hologram which would otherwise be incident to the hologram at angles outside the prescribed range of angles required for substantial diffraction by the hologram. In this manner background light which would otherwise be transmitted through a hologram so as to degrade the quality of a stereoscopic image reconstructed from the hologram is precluded from ever reaching the viewing area.

Growing community of inventors

Lincoln, MA, United States of America

Stephen A Benton