Symbol/raster generator for CRT display
First Claim
1. A multiple function digital signal generator for generating CRT display beam position signals, comprising:
- a controller for providing sequential digital control bytes defining a sequence of line segments to make up a given vector, said control bytes comprising a data word and a destination address word to define the destination circuitry for converting said data word into polar coordinate data;
first destination circuitry comprising angle accumulating means responsive only to data words directed to said first circuitry by said address word for accumulating polar coordinate angle data dA and an initial angle value AO over a selected time interval to provide an accumulated angle value A;
means for summing said accumulate angle value A with another angle value B to provide a polar coordinate angle value;
a second destination circuitry responsive to data words directed to said second circuitry and comprising an integrating vector generator responsive to said polar coordinate angle value for providing X and Y position signals in digital form, and a Z axis beam intensity signal, said generator comprising coordinate transformation means for transforming polar coordinate data comprising said polar coordinate angle value and a step size dR into cartesian coordinates dX and dY, and for integrating said cartesian coordinate data into said X and Y position signals; and
a third destination circuitry responsive only to data words directed thereto by a destination address word identifying said third destination circuitry, said circuitry comprising means for converting said data word into corresponding polar coordinate data comprising an angle value B and a step size dR required for generating a second type of CRT imagery, said angle value B for input to said summing means and said step size dR for input to said integrating vector generator,and wherein said signal generator is capable of generating an arc raster line as a first CRT imagery type by drawing a series of vectors, each of step size dR, and wherein the angle between adjacent vectors changes by dA, said values dA and dR being selected by data words provided by said controller, and wherein said signal generator is further capable of selectively generating said second type of CRT imagery by directing appropriate data words to said third destination circuitry, by use of a single integrating vector generator.
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Accused Products
Abstract
A symbol/raster generator system for a CRT display system is described, having the capability of generating raster-scanned display signals or vector symbology. The system includes a polar coordinate transformation circuit which transforms polar coordinate beam deflection data into corresponding X and Y beam deflection control signals. The system includes an angle accumulator for accumulating incremental angular data over time, and sine and cosine PROMS for providing the sine and cosine of the accumulated angle value. X and Y multiplier circuits provide respective incremental dX and dY values corresponding to the respective products of the cosine and sine values with a step size value dR. The incremental dX and dY values are accumulated over time to provide the X and Y beam deflection signals. The system further includes circuits for providing the angle data and step size dR so as to generate rasters, 8 and 16-side characters, curved and slanted characters, conic symbology, and other types of special symbols. The rasters can be arc-scanned rasters as required in radar displays, e.g., plan position indicator (PPI), SAR, angular and radial scan. The system provides an integrated and highly versatile raster/symbol generator for CRT displays.
29 Citations
15 Claims
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1. A multiple function digital signal generator for generating CRT display beam position signals, comprising:
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a controller for providing sequential digital control bytes defining a sequence of line segments to make up a given vector, said control bytes comprising a data word and a destination address word to define the destination circuitry for converting said data word into polar coordinate data; first destination circuitry comprising angle accumulating means responsive only to data words directed to said first circuitry by said address word for accumulating polar coordinate angle data dA and an initial angle value AO over a selected time interval to provide an accumulated angle value A; means for summing said accumulate angle value A with another angle value B to provide a polar coordinate angle value; a second destination circuitry responsive to data words directed to said second circuitry and comprising an integrating vector generator responsive to said polar coordinate angle value for providing X and Y position signals in digital form, and a Z axis beam intensity signal, said generator comprising coordinate transformation means for transforming polar coordinate data comprising said polar coordinate angle value and a step size dR into cartesian coordinates dX and dY, and for integrating said cartesian coordinate data into said X and Y position signals; and a third destination circuitry responsive only to data words directed thereto by a destination address word identifying said third destination circuitry, said circuitry comprising means for converting said data word into corresponding polar coordinate data comprising an angle value B and a step size dR required for generating a second type of CRT imagery, said angle value B for input to said summing means and said step size dR for input to said integrating vector generator, and wherein said signal generator is capable of generating an arc raster line as a first CRT imagery type by drawing a series of vectors, each of step size dR, and wherein the angle between adjacent vectors changes by dA, said values dA and dR being selected by data words provided by said controller, and wherein said signal generator is further capable of selectively generating said second type of CRT imagery by directing appropriate data words to said third destination circuitry, by use of a single integrating vector generator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification