United States Patent
US Patent 4197590: Method for dynamically viewing image elements…
US 4197590 · granted 1980-04-08
Abstract
A computer graphics display system including random access raster memory for storing data to be displayed, a raster memory control unit for writing data into the raster memory, a video control unit for causing such information to be displayed on a CRT display screen, a micro control unit for controlling the function and timing of the raster memory control unit and the video control unit, and a computer adapted for facilitating data exchange between the micro control unit and a host computer. The displayed image can have extremely high complexity with essentially no problem of display flicker. Zoom and pan features allow the use of a very complex stored image in a flexible manner, and a split-screen technique enables an operator to work on a very complex picture at a detail level while still having an overview of the total picture, or any portion thereof, simultaneously presented before him. The split-screen feature also allows the simultaneous display of alphanumeric messages such as prompts, menus, or X-Y readouts added to the graphics display and a small area of the raster memory is usually reserved for this purpose. An XOR feature allows a selective erase that restores lines crossing or concurrent with erased lines. The XOR feature permits part of the drawing to be moved or "dragged" into place without erasing other parts of the drawing.
| Patent Number | 4197590 |
|---|---|
| Title | Method for dynamically viewing image elements stored in a random access memory array |
| Filed | 1978-01-19 |
| Granted | 1980-04-08 |
| Inventor(s) | Sukonick; Josef S., Tilden; Greg J. |
| Assignee | NuGraphics, Inc. |
| Number of Claims | 119 |
Abstract
A computer graphics display system including random access raster memory for storing data to be displayed, a raster memory control unit for writing data into the raster memory, a video control unit for causing such information to be displayed on a CRT display screen, a micro control unit for controlling the function and timing of the raster memory control unit and the video control unit, and a computer adapted for facilitating data exchange between the micro control unit and a host computer. The displayed image can have extremely high complexity with essentially no problem of display flicker. Zoom and pan features allow the use of a very complex stored image in a flexible manner, and a split-screen technique enables an operator to work on a very complex picture at a detail level while still having an overview of the total picture, or any portion thereof, simultaneously presented before him. The split-screen feature also allows the simultaneous display of alphanumeric messages such as prompts, menus, or X-Y readouts added to the graphics display and a small area of the raster memory is usually reserved for this purpose. An XOR feature allows a selective erase that restores lines crossing or concurrent with erased lines. The XOR feature permits part of the drawing to be moved or "dragged" into place without erasing other parts of the drawing.
Claim 1
A method of generating a graphics display having the illusion of smooth panning across an image represented by a plurality of discrete picture elements, said image beinglarger than that which can be displayed at one time on a video display device, comprising: storing in the storage sites of a memory device a set of digital data corresponding to the discrete picture elements of said image, selected subsets of said digital data being readable from said memory to produce a corresponding raster signaldisplayable by said video display device; specifying a first particular portion of said memory storage sites, said first particular portion containing a first subset of digital data corresponding to a first part of said image, said first part being displayable at one time on said videodisplay device; selecting a second particular portion of said memory storage sites, said second particular portion containing a second subset of digital data corresponding to a different, second part of said image, said second part also being displayable at onetime on said video display device, selecting a plurality of other portions of said memory storage sites, said other portions each containing a respecti
Claims
119 totalA method of generating a graphics display having the illusion of smooth panning across an image represented by a plurality of discrete picture elements, said image beinglarger than that which can be displayed at one time on a video display device, comprising: storing in the storage sites of a memory device a set of digital data corresponding to the discrete picture elements of said image, selected subsets of said digital data being readable from said memory to produce a corresponding raster signaldisplayable by said video display device; specifying a first particular portion of said memory storage sites, said first particular portion containing a first subset of digital data corresponding to a first part of said image, said first part being displayable at one time on said videodisplay device; selecting a second particular portion of said memory storage sites, said second particular portion containing a second subset of digital data corresponding to a different, second part of said image, said second part also being displayable at onetime on said video display device, selecting a plurality of other portions of said memory storage sites, said other portions each containing a respecti