Complex conjugate hologram display

• US 4,880,287 A
• Filed: 01/06/1987
• Issued: 11/14/1989
• Est. Priority Date: 01/06/1987
• Status: Expired due to Term

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Moss, Gaylord E.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/000,792
• Time in Patent Office: 1,043 Days
• Field of Search: 350/3.6, 350/3.7, 350/3.72, 350/174, 350/3.85, 350/3.86, 350/3.65
• US Class Current: 359/14
• CPC Class Codes: G02B 2027/0107 with optical power
• CPC Class Codes: G02B 2027/0109 comprising details concerning the making of holograms
• CPC Class Codes: G02B 2027/0145 creating an intermediate image
• CPC Class Codes: G02B 27/0103 comprising holographic elements
• CPC Class Codes: G03H 1/041 Optical element in the object space affecting the object beam, not otherwise provided for
• CPC Class Codes: G03H 1/0486 Improving or monitoring the quality of the record, e.g. by compensating distortions, aberrations
• CPC Class Codes: G03H 1/22 Processes or apparatus for obtaining an optical image from holograms G03H1/26 - G03H1/34 take precedence
• CPC Class Codes: G03H 1/2205 using downstream optical component
• CPC Class Codes: G03H 2001/2231 Reflection reconstruction
• CPC Class Codes: G03H 2001/2234 Transmission reconstruction

Abstract

Aberration in an image reflected from a warped surface such as an automobile windshield is corrected by providing an image to the windshield which is predistorted to compensate for the aberration. The predistorted image is created and stored in a hologram by a recording technique wherein a first transmission hologram which records the virtual image of an object is illuminated with a conjugate beam. The beam which is transmitted by the first transmission hologram is reflected off the windshield onto a second hologram recording plate, which is also illuminated by a reference beam passed through the windshield. The desired predistorted image is thereby stored in the second hologram recording plate.

Claims

1. A display system comprising:

an illumination source;

a combiner means which imparts an aberration to an image; and

a hologram means illuminated by said source for providing an image to said combiner means including predistortion to compensate for said aberration.

2. The display of claim 1 wherein said combiner source means comprises a vehicle windshield.

3. The apparatus of claim 2 wherein said hologram means is a transmission hologram and wherein said display is formed by directing illumination from an illumination source through said transmission hologram to said windshield.

4. The apparatus of claim 2 wherein said hologram means is a reflection hologram and wherein said display is formed by reflecting illumination from an illumination source off said reflection hologram and onto said windshield.

5. A hologram made according to the steps of:

making a first hologram of an object at a distance L from an observer recording the virtual image of the object;

making a second hologram by illuminating the first hologram with its conjugate reference beam and reflecting the light from said first hologram off a warped combiner means and onto a second hologram plate; and

illuminating the second hologram plate with a reference beam passed through said warped combiner means.

6. The hologram according to claim 5 wherein said warped combiner means comprises a vehicle windshield.

7. In an automobile, apparatus comprising:

a windshield; and

display apparatus for generating a display viewable by looking at said windshield, said display apparatus including a hologram means for generating said display and reflecting said display off said windshield and wherein said hologram means contains a diffraction grating means for producing said display with predistortion, the predistortion being designed to offset the abberrational effect of said windshield.

8. The apparatus of claim 7, wherein said hologram is a transmission hologram and wherein said display is formed by directing illumination from an illumination source through said transmission hologram to said windshield.

9. The apparatus of claim wherein said hologram is a reflection hologram and wherein said display is formed by reflecting illumination from an illumination source off of said reflection hologram and onto said windshield.