Holographic projection screen

• US 4,500,163 A
• Filed: 07/29/1981
• Issued: 02/19/1985
• Est. Priority Date: 07/29/1981
• Status: Expired due to Fees

• Current Assignee: Hughes Aircraft Company (Rtx Corporation)
• Original Assignee: Singer PLC (Hayleys Plc)
• Inventors: Burns, Richard H., Hall, William M., Hildebrand, Bernard P.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Propp, William
• Application Number:
  US06/288,085
• Time in Patent Office: 1,301 Days
• Field of Search: 350/97, 350/103, 350/125, 350/129, 350/162.16, 350/162.23, 350/320, 350/3.7, 358/60
• US Class Current: 359/15
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G03B 21/56 Projection screens
• CPC Class Codes: G09B 9/326 the image being transformed by optical means

Abstract

A projection screen is formed as at least one reflective holograms each of which, when referenced with a projector, reconstructs a defined observation pupil.

Claims

1. A front projection viewing screen having a fixed size observation pupil at a predetermined position relative to the screen, said screen comprising an array of a plurality of elemental screen areas wherein each of said elemental screen areas is formed of at least one elemental reflective hologram of the observation pupil, and wherein each of said holograms is made with a specular object beam.

2. The screen according to claim 1 wherein said screen is of generally spherical shape and said observation pupil is within the sphere of said screen.

3. The screen according to claim 1 wherein said screen is of generally spherical shape and wherein said elemental holograms disposed at a given height are identical.

4. The screen according to claim 1 wherein each of said elemental holograms is formed with an object beam focused at a point behind said elemental hologram.

5. The screen according to claim 4 wherein during the formation of each of said elemental holograms a masked aperture is positioned between said point and said elemental hologram to direct light from said point to said observation pupil.

6. A method for producing a front projection viewing screen having a fixed size observation pupil at a predetermined position relative to said screen comprising the steps of:

(a) forming a plurality of elemental reflective holograms of said observation pupil using a specular object beam in each such formation; and

(b) arranging said elemental holograms in an array to form the viewing surface of said screen;

wherein each of said elemental holograms is formed at a position relative to said observation pupil that each of said elemental holograms has in said array.

7. The method according to claim 6 wherein the arranging step includes the step of positioning said elemental holograms to form a generally spherical screen around said observation pupil.

8. The method according to claim 6 wherein the arranging step includes the step of positioning said elemental holograms to form a generally spherical screen and wherein during the forming step all of said elemental holograms which are to be positioned at a given height are formed to be mutually identical.

9. The method according to claim 6 wherein the forming step includes the step of focusing said object beam at a point behind said elemental hologram.

10. The method according to claim 9 wherein the forming step further includes the step of positioning a masked aperture between said point and said elemental hologram to direct light from said point to said observation pupil.