Digital stroke display with vector, circle and character generation capability
US4115863A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 7, 1976 |
| Grant date | Sep 19, 1978 |
| Priority date | — |
| Expiry date | Dec 7, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G1/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The digital stroke display generates vectors by applying clock pulses to an up/down counter which through a digital-to-analog converter provides the deflection voltage for one of the display X or Y axes. The clock pulses are applied through a gate to a second up/down counter which through a second digital-to-analog converter provides the deflection voltage for the other of the X and Y axes. The gate is controlled by the overflow of an accumulator that is repetitively accumulating, under control of the clock pulses, a signal representative of the desired slope of the vector. Circular curves are generated by a concatanated series of vectors utilizing the vector generation apparatus where the signal representative of the vector slope is provided from a memory that stores the plurality of slopes for the concatanated vectors that comprise the circular curve. A signal representing the curvature of the circular curve is accumulated in a second accumulator, the outut of which provides the addresses for the slope memory. Characters are generated by the vector generation apparatus in response to a sequence of stored vector control words for writing a series of vectors comprising the desired …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.