LED array polarized image source/0 degree hologram virtual image head up display

• US 5,044,709 A
• Filed: 11/30/1988
• Issued: 09/03/1991
• Est. Priority Date: 11/30/1988
• Status: Expired due to Fees

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: McDonald, Mark, Smith, Ronald T.
• Primary Examiner(s): Arnold, Bruce Y.
• Assistant Examiner(s): Ryan, J. P.
• Application Number:
  US07/278,083
• Time in Patent Office: 1,007 Days
• Field of Search: 350/3.7, 350/174, 350/162.2, 350/3.65, 350/172
• US Class Current: 359/13
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 27/0103 comprising holographic elements
• CPC Class Codes: G02B 27/1093 for use with monochromatic radiation only, e.g. devices for splitting a single laser source
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00

Abstract

A holographic display system having a dynamic image source including selectively activated light emitting diodes for providing spectrally narrowband and narrow beam imaging illumination through an apertured mask, and further having a mirror reflection hologram for reflecting the image to provide an observable virtual image. The image source further includes a polarizer and an optional diffuser.

Claims

1. A virtual image display system comprising:

means for providing a dynamically changing image comprising means for providing beams of light having a narrow spectral bandwidth of less than about 50 nanometers, wherein said means for providing light beams includes light emitting diodes and a mask having openings for selectively masking the illumination provided by said light emitting diodes; and

a reflection hologram having fringe planes equidistant to the hologram surface for reflecting the image to produce an observable virtual image.

2. The virtual image display system of claim 1 wherein said means for providing light beams further includes a polarizer.

3. The virtual image display system of claim 1 wherein said means for providing light beams further includes a diffuser.

4. The virtual image display system of claim 1 wherein said mirror reflection hologram having fringe planes equidistant to the hologram surface is tuned to the spectral bandwidth of said image providing means.

5. The virtual image display system of claim 1 wherein said reflection hologram having fringe planes equidistant to the hologram surface is tuned to the P-polarization spectral bandwidth of said image providing means.

6. A virtual image display system comprising:

means for providing dynamically changing illumination having a narrow spectral bandwidth of less than about 50 nanometers wherein illumination providing means includes light emitting diodes and a mask having openings for selectively masking the illumination provided by said light emitting diodes; and

a non-slanted mirror refection hologram having fringe planes equidistant to the hologram surface tuned to be reflective over the spectral bandwidth of said illumination providing means for reflecting said narrowband illumination to produce an observable virtual image.

7. The virtual image display system of claim 6 wherein said illumination providing means includes a polarizer.

8. The virtual image display system of claim 7 wherein said illumination providing means includes a diffuser.

9. A virtual image display system comprising:

means for providing dynamically changing illumination having a narrow spectral bandwidth of less than about 50 nanometers wherein said illumination providing means includes light emitting diodes and optical elements for selectively masking the illumination provided by said light emitting diodes; and

a mirror reflection hologram having fringe planes equidistant to the hologram surface tuned to be reflective over the spectral bandwidth of said illumination providing means for reflecting said narrowband illumination to produce an observable virtual image;

said narrowband illumination being substantially confined to an eyebox spatial region.