Hughes Aircraft Company

Bruce W Keller

Michael D Pruznick

James L Heard

Michael N Ernstoff

Eugene W Opittek

Thomas A Bosseler

James R Phelps

Gerald Wolfson

A symbol smoothing system for synthetically increasing the effective resolution of an in-raster symbol generator memory by a factor of four. The system stores a special three bit code in selected memory elements representative of the existing and past two memory lines with the code actually being a video brightness distribution and positioning offset code. A code number in a single memory cell defines positional and intensity information for the display elements corresponding to that memory cell and to selected surrounding eight memory cells, all of the memory cells having time or positional correspondence to display element positions. The stored codes in the surrounding memory cells, as well as the instantaneous memory cell being decoded, provide intensity levels which are combined at selected display element positions. The video data input for each memory cell consists of the fractional X and Y position bit and symbol type bit and from each memory element, eight additional display elements are developed having selected brightness levels. By decoding this code bit information, the in-raster symbology provides a smooth transition from one display line to the next so as to eliminate the staircase effect in rotated or non-orthogonal lines. For each memory cell in a first field, such as the odd field, every other display resolution element is generated principally from the code in the memory cell and the alternate resolution element is generated principally from the same code. For the other field, such as the even field, the two elements on the display are generated principally from same information code in the memory cell. Further, each resolution element defined by a memory cell can have its intensity increased by codes stored in surrounding memory cells. The three bit memory codes define the location of the imaginary display elements and the video distribution patterns, which patterns simulate a gaussian brightness distribution to temper the edge sharpness of the digitally derived symbology. Thus by storing a single code for each selected memory cell, the system by proper decoding of the codes stored in that memory cell and the surrounding memory cells, develops both positional and intensity display information for the display elements while increasing the effective resolution of the in-raster symbol generator refresh memory by a factor of four. Another feature in accordance with the invention is the use of a common decoding structure by altering the stored codes with a bit rotator so as to be compatible with the common decoding structure, with the altered code representing the correct condition to be decoded.

In-raster symbol smoothing system

A digital scan converter which comprises modular video processing units and modular memory and output units is adapted for processing applied sensor data of various formats so as to provide output data suitable for display on a common indicator. Parameters for processing operations, such as analog-to-digital converting, integrating and detecting, are implemented by the video processing modules in response to digital 'set-up' and address words applied from a programmed microprocessor controller. The storage and readout format of the memory and output modules is also controlled by 'set-up' and address words applied from the programmed controller.

Modular programmable digital scan converter

A low bandwidth high brightness display system that utilizes a multiple beam cathode ray tube to write multiple rasters by concurrently scanning a plurality of lines with a selected number of beams. Each of the rasters covers a different portion of the screen so that the vertical deflection of the beam is reduced for each beam by a factor related to the number of beams. The system reduces the maximum data rate in writing speed relative to conventional arrangements with a resultant bandwidth reduction proportional to the number of beams. The concept is applicable to television viewing screens and field sequential color television to produce simultaneously a high resolution, high brightness and high quality display.

Multiple beam CRT for generating a multiple raster display

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Scotland, AR, United States of America

Bruce W Keller