Data projection system with compensation for nonplanar screen

• US 5,161,013 A
• Filed: 04/08/1991
• Issued: 11/03/1992
• Est. Priority Date: 04/08/1991
• Status: Expired due to Term

• Current Assignee: Theseus Research, Inc.
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Egli, Werner H., Rylander, Karen S., Fant, Karl M.
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Powell, Mark R.
• Application Number:
  US07/681,914
• Time in Patent Office: 575 Days
• Field of Search: 395/125, 395/127, 395/128, 340/729, 358/160, 358/231
• US Class Current: 348/744
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT

Abstract

A data projection system in which a data projector having a data display memory associated therewith projects images to a viewing screen. The system includes a curved or nonplanar viewing screen and computer software effective to provide viewing fidelity by compensating for inaccuracies of the viewing screen.

Claims

1. A data projection system, said system comprising,

computer means including a buffer memory and a display memory,

a graphics program runnable by said computer means to generate display data for said display memory,

projection and view points laterally spaced from each other,

data projector means having access to said display memory and being operable to output a pixelized image from said display memory in the form of diverging rays diverging from said projection point,

a viewing screen having a curved reflecting surface for receiving said divergent rays and reflecting them in the form of converging rays converging at said view point,

a virtual output screen in a plane between said projection point and said reflection surface having a rectangular array of output pixels formed by said diverging rays and representing said display data,

a virtual view screen in a plane between said view point and said reflecting surface having a rectangular array of view pixels formed by said converging rays and corresponding respectively to said output pixels,

a reference table having size ratios representing comparisons of dimensional size parameters of said pixels of said virtual view screen relative to corresponding ones of said pixels of said virtual output screen, and

said graphics program being adapted to utilize said size ratios listed in said reference table to condition said display data so as to compensate for inaccuracies of said virtual view screen relative to said virtual output screen due to inaccuracies of said reflecting surface.

2. A data projection system according to claim 1 wherein said graphics program being a method of mapping from a 2D input image in a 3D coordinate system to said display memory, said graphics program having a two pass mode wherein with a vertical pass vertical lines of pixels derived from said input image are mapped to said buffer memory to form an intermediate image therein, and with a horizontal pass horizontal lines of pixels of said intermediate image are mapped to said display memory to form a display image therein.

3. A data projection system according to claim 1 wherein said reflecting surface is a concave surface.

4. A data projection system according to claim 1 wherein said size ratios are for pixel height and width comparisons.

5. A data projection system according to claim 1 wherein said size ratios are for pixel area comparisons.

6. A data projection system according to claim 1 wherein said virtual output and view screens have the same height and width dimensions.

9. A data projection system according to claim 2 wherein said size ratios are for pixel area comparisons.

7. A data projection system of the type having projection and view points laterally spaced from each other, said system comprising,

data projector means having a display memory associated therewith and being operable to output a pixelized image from said display memory in the form of diverging rays diverging from said projection point,

a reflecting surface for receiving said divergent rays and reflecting them in the form of converging rays converging at said view point,

a virtual output screen in a plane between said projection point and said reflecting surface having a rectangular array of output pixels formed by said diverging rays and representing said display memory,

a virtual screen in a plane between said view point and said reflecting surface having a rectangular array of view pixels formed by said converging rays and corresponding respectively to said output pixels,

a reference table having size ratios representing comparisons of dimensional size parameters of said pixels of said virtual view screen relative to corresponding ones of said pixels of said virtual output screen,

program means for processing input data to provide said display memory with display memory data for a desired output to said view point,

said program having means for altering said input data in accordance with said size ratios of said reference table to compensate for inaccuracies of said reflecting surface.

8. A data projection system according to claim 7 wherein said program means operate to map said input data to said display memory with a single pass.

10. A data projection system according to claim 7 wherein said program means operates to map said input data to a buffer memory via a vertical pass and sequentially from said buffer memory to said display memory via a horizontal pass.

11. A data projection system according to claim 10 wherein said program means operates to alter said input data only during said second pass and said size ratios are for pixel area comparisons.

12. A data projections system according to claim 10 wherein said program means operates to alter said input data during said first pass by applying said size ratios which are for pixel height comparisons and to alter said input data during said second pass by applying said size ratios which are for pixel width comparisons.