Black optic display

• US 5,625,736 A
• Filed: 01/11/1996
• Issued: 04/29/1997
• Est. Priority Date: 01/11/1996
• Status: Expired due to Fees

• Current Assignee: Brookhaven Science Associates, LLC (Government of the United States of America)
• Original Assignee: Associated Universities, Inc.
• Inventors: Veligdan, James T.
• Primary Examiner(s): Ullah, Akm E.
• Application Number:
  US08/584,046
• Time in Patent Office: 474 Days
• Field of Search: 385/120, 385/115, 385/116, 385/121, 385/125, 385/129, 385/130-132, 385/901, 385/1, 385/4, 362/32, 358/901.1, 348/804, 40/547, 359/630, 359/633, 359/559, 359/9, 359/29
• US Class Current: 385/120
• CPC Class Codes: G02B 6/08 with fibre bundle in form of plate
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

An optical display includes a plurality of stacked optical waveguides having first and second opposite ends collectively defining an image input face and an image screen, respectively, with the screen being oblique to the input face. Each of the waveguides includes a transparent core bound by a cladding layer having a lower index of refraction for effecting internal reflection of image light transmitted into the input face to project an image on the screen, with each of the cladding layers including a cladding cap integrally joined thereto at the waveguide second ends. Each of the cores is beveled at the waveguide second end so that the cladding cap is viewable through the transparent core. Each of the cladding caps is black for absorbing external ambient light incident upon the screen for improving contrast of the image projected internally on the screen.

Claims

1. An optical display 10B comprising:

a plurality of stacked together optical waveguides 12 having first and second opposite ends 12a,b defining an image input face 16 and an image screen 18, respectively, with said screen 18 being oblique to said input face 16;

each of said waveguides 12 including a transparent core 12c bound by a cladding layer 12d having a lower index of refraction for effecting internal reflection of image light 22 transmitted into said input face 16 to project an image 24 on said screen 18, with each of said cladding layers 12d including a cladding cap 12x integrally joined thereto at said waveguide second ends 12b;

each of said cores 12c being beveled at said waveguide second end 12b so that said cladding cap 12x is viewable through said transparent core 12c; and

each of said cladding caps 12x being black for absorbing external ambient light 34 incident upon said screen 18 for improving contrast of said image 24 projected internally on said screen 18.

2. A display according to claim 1 wherein each of said waveguide second ends 12b has a bevel height, and said cladding cap 12x has a cap height at least as large as said bevel height for providing overlapping black cladding caps 12x continuously across said screen 18.

3. A display according to claim 2 wherein said cladding caps 12x are disposed solely adjacent to said waveguide second ends 12b, with said cladding layers 12d extending from respective ones of said caps 12x to said input face 16.

4. A display according to claim 2 wherein said cladding caps are integral with said cladding layers 12y and extend from said input face 16 to said screen 18, and are both black for absorbing ambient light at said screen 18, and have a lower index of refraction than said cores 12c for internally reflecting said image light therethrough.

5. A display according to claim 2 wherein said waveguides 12 are in the form of ribbons each having generally rectangular cross-sections from said input face 16 to said screen 18.

6. A display according to claim 5 wherein said screen 18 is almost parallel to said waveguides 12.

7. A display according to claim 2 wherein said cladding caps 12x comprise lampblack carbon suspended in epoxy.

8. A display according to claim 2 in combination with light providing means 20 for providing image light into said input face 16 within an acceptance angle for internally reflecting substantially all incident image light through said cores 12c to said screen 18.

9. A display combination according to claim 8 wherein said light providing means 20 is in the form of a scanning laser 20a effective for emitting a laser beam 22 into said input face 16, said beam 22 being scannable both horizontally along said waveguide first ends 12a to effect a horizontal scan in said screen 18, and from waveguide-to-waveguide in said input face 16 to effect a vertical scan in said screen 18, with each scan location defining a discrete pixel 28.

10. A display combination according to claim 9 wherein the number of said pixels 28 in said vertical scan is equal to the number of said waveguides 12, and the number of said pixels 28 in said horizontal scan is selectively variable by said light providing means 20.

11. A display combination according to claim 8 wherein each of said waveguides 12 is planar.

12. A display combination according to claim 8 wherein said beveled cores 12c are frosted at said screen 18 for diffusing said image light emitted therefrom.

13. A black optical display comprising:

a plurality of light channeling optical waveguides 12 each having a first end 12a for passing light, an opposite, second end 12b for passing light, and a longitudinal axis 14 extending between said first and second ends 12a, 12b, said waveguides 12 being stacked laterally together from said first to second ends 12a, 12b, with said longitudinal axes 14 being generally parallel to each other;

said first ends 12a of all said waveguides 12 being disposed generally coplanar and collectively defining a panel first face 16;

said second ends 12b of all said waveguides 12 being disposed generally coplanar and collectively defining a panel second face 18;

said panel second face 18 being disposed at an acute face angle relative to said longitudinal axes 14 of said waveguides 12 thereby to define an intermediate section 10a of said panel extending from a front one 12e of said waveguides 12 to an opposite back one 12f of said waveguides 12;

said panel having a maximum thickness at said intermediate section 10a and tapering in thickness along said panel second face 18 from said front waveguide 12e to said back waveguide 12f, and tapering in length between said intermediate section 10a and said waveguide second ends 12b from said back waveguide 12f to said front waveguide 12e;

said panel maximum thickness being less than said length of said back waveguide 12f from said second end 12b thereof to said intermediate section 10a, and being less than the height of said panel second face 18 from said front waveguide 12e to said back waveguide 12f;

each of said waveguides 12 including a transparent core 12c bound by a cladding layer 12d having a lower index of refraction for effecting internal reflection of image light 22 transmitted into said input face 16 to project an image 24 on said screen 18, with each of said cladding layers 12d including a cladding cap 12x integrally joined thereto at said waveguide second ends 12b; and

each of said cladding caps 12x being black for absorbing external ambient light 34 incident upon said screen 18 for improving contrast of said image 24 projected internally on said screen 18.