Holographic full color data retrieval and projection system

• US 5,011,244 A
• Filed: 12/16/1988
• Issued: 04/30/1991
• Est. Priority Date: 12/16/1988
• Status: Expired due to Fees

• Current Assignee: Dai Nippon Printing Company Limited
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Smith, Ronald T., Hegg, Ronald G.
• Primary Examiner(s): Arnold, Bruce Y.
• Assistant Examiner(s): Ryan, Jay P.
• Application Number:
  US07/285,898
• Time in Patent Office: 865 Days
• Field of Search: 350/3.6, 350/3.67, 350/3.70, 350/3.73, 350/3.75, 350/3.77, 350/3.78, 350/3.81
• US Class Current: 359/22
• CPC Class Codes: G02B 5/0252 using holographic or diffractive means
• CPC Class Codes: G03H 1/26 Processes or apparatus specially adapted to produce multiple sub- holograms or to obtain images from them, e.g. multicolour technique
• CPC Class Codes: G03H 2001/0439 for recording Holographic Optical Element [HOE]
• CPC Class Codes: G03H 2223/12 Amplitude mask, e.g. diaphragm, Louver filter
• CPC Class Codes: G03H 2260/10 Dichromated gelatine or equivalents
• CPC Class Codes: G03H 2260/16 Silver halide emulsion
• CPC Class Codes: G11C 13/046 using other storage elements storing information in the form of an interference pattern

Abstract

A holographic full-color, data retrieval and projection system includes a holographic information storage plate that includes a plurality of reflective holograms, each designed to diffract light over a certain spectral bandwidth, and a holographic screen character plate, which includes a plurality of screen hologram character shapes that reflect diffracted light in a uniform, well-defined cone of diffuse light directed toward the viewer, producing images having high screen gain and high brightness, yet with lower power consumption than heretofore obtained.

Claims

1. A holographic data retrieval and projection system comprising:

a low-power light source means for producing a collimated beam of white light;

at least one reflective holographic information storage plate including a plurality of holographic elements wherein each of said elements diffracts incident light over a predetermined, desired spectral bandwidth; and

a holographic screen character plate comprising a plurality of reflective screen character holograms in predetermined, desired shapes and sizes, each screen character hologram being adapted to diffract light lying within a wavelength band which includes the incident light thereon in a uniform well-defined bundle of diffuse light directed toward a viewer, each screen character hologram being tuned to diffract a predetermined, desired color of light, and to transmit all other light colors incident thereon, said information storage plate and said screen character storage plate being spaced from one another and oriented so that the various light colors diffracted from said information storage plate strike predetermined, desired screen character hologram locations on said screen character storage plate.

2. The system of claim 1 wherein said holographic elements in said storage plate lie entirely within a single gelatin layer.

3. The system of claim 1 wherein said holographic elements in said storage plate consist of a stack of gelatin layers each incorporating at least one hologram.

4. The system of claim 1 wherein said storage plates comprises a plurality of holographic elements each having a narrow response bandwidth.

5. The system of claim 1 wherein said storage plates comprises a plurality of holographic elements each having a relatively wide response bandwidth.

6. The system of claim 1 wherein said storage plates comprise a plurality of holographic elements each having a spectral bandwidth sufficiently different from the spectral bandwidths of physically adjacent holographic elements to minimize diffraction of undesired wavelengths of light by said adjacent holographic elements.