Display system for displaying information in the form of a horizontally oriented curve on a raster type CRT
US4117473A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1977 |
| Grant date | Sep 26, 1978 |
| Priority date | — |
| Expiry date | Jan 25, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G1/162
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A horizontally oriented curve is produced on a raster type cathode ray tube display by storing curve data words in a memory and placing a series of dots on the cathode ray tube screen with each dot being at a height dictated by the value of the respective data word and at a horizontal position dependent on the order in which the respective data word is received. A dot counter provides an output signal for writing the curve data words into the address locations of the memory in the order in which the curve data words are received. A horizontal raster position counter provides a read address signal to the memory for each possible dot position in a horizontal scan. A comparator circuit compares each curve data word read out of the memory with a signal representative of the vertical position of the current horizontal scan and produces a video enable signal to produce a dot on the cathode ray tube screen when the compared signals are equal. Means can be provided to fill in vertical gaps when there is one or more horizontal scans between vertically adjacent curve data points.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.