DISPLAY SYSTEMS

• US 3,679,297 A
• Filed: 02/26/1970
• Issued: 07/25/1972
• Est. Priority Date: 02/28/1969
• Status: Expired due to Term

• Current Assignee: Christopher H.C. Walker, Simon M. St. L. Searle
• Original Assignee: Christopher H.C. Walker, Simon M. St. L. Searle
• Inventors: Searle, Simon M. St. L., Walker, Christopher H. C.
• Primary Examiner(s): Forman, Leonard
• Assistant Examiner(s): Stephan, Steven L.
• Application Number:
  US05/014,439
• Time in Patent Office: 880 Days
• Field of Search: 353/14,84,11,12,13,31,35 116/129R 35/12N 356/251CL 350/174,316 73/178R
• US Class Current: 353/14
• CPC Class Codes: G02B 2027/0154 with movable elements
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence

Abstract

An aircraft head-up display is projected from symbol-markings borne by two complementary color filters superimposed in the light-path from an electric lamp. An horizon-line marking of the first filter has the color of the second filter bearing a flightvector marking, and vice versa, but either marking may be transparent. The filters are separately driven to follow aircraft movements with the symbol-images simulating the true horizon and flight-vector. A third filter with glide-slope marking may be carried adjustably with the first filter to allow modification of indicated glide-slope below the horizon.

Claims

1. A display system comprising means defining a display area, means directing light along a path to said display area, two color filters positioned one in front of the other in said lightpath, a first of the color filters having a first color-band light-transmission characteristic and bearing a first symbolmarking that has a second color-band light-transmission characteristic, said first and second color-band lighttransmission characteristics occupying different and mutually exclusive parts of the spectrum of said light, the second color filter having said second color-band light-transmission characteristic and bearing a second symbol-marking that has said first color-band light-transmission characteristic, whereby images of said first and second symbol-markings appear in different colors to one another in said display area, and means for effecting movement of at least one of said color filters relative to the other color filter to modify the relationship of the symbol-images to one another in said display area.

2. A display system comprising means defining a display area, means directing light along a path to said display area, two color-filters positioned one in front of the other in said light-path, each filter bearing symbol-marking and presenting to the light, except at its symbol-marking, a color-band light-transmission characteristic which characteristic is different from that of the other said filter, the symbol-marking of one of the filtErs having the same color-band light-transmission characteristic as the other of the two filters and the symbol-marking of each of the two filters having a light-transmission characteristic that includes the color-band of the other filter whereby images of the symbols represented by the markings on the two filters appear in the display area, and means for effecting movement of at least one of the filters relative to the other to modify thereby the relationship of the symbol-images to one another in the display area.

3. A display system according to claim 2 including a partially-transparent reflector and optical means for projecting the images of the symbols onto the reflector.

4. A display system according to claim 2 including a filter bearing a symbol-marking fully transparent to said light.

5. A display system according to claim 2 wherein the filters are color-film transparencies.

6. A display system according to claim 2 including electromechanical devices for moving the filters relative to one another.

7. A display system according to claim 2 including two filters carried one with the other, and wherein the said movement-effecting means includes a manually-adjustable device for adjusting the positions of these two filters relative to one another.

8. A display system according to claim 2 for use in an aircraft, including means for responding to movements of the aircraft to effect relative movements of the filters.

9. A display system according to claim 8 wherein one of the filters bears a symbol-marking in the form of an horizon line, and said means for responding to movements of the aircraft includes means to move this filter in accordance with aircraft-movements in elevation and bank so that the image of said horizon line appearing in the display area provides appropriate simulation of the true horizon.

10. A display system according to claim 8 wherein one of the filters bears a symbol-marking indicative of the flight-direction of the aircraft, and said means for responding to movements of the aircraft includes means to move this filter in accordance with aircraft-movements in elevation and azimuth so that the image of the flight-direction symbol appearing in the display area provides appropriate simulation of the direction of flight of the aircraft.