Pulse width modulation greyscale system for halftone printer
US4661859A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1981 |
| Grant date | Apr 28, 1987 |
| Priority date | — |
| Expiry date | Jun 3, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4078
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A one dimensional electronic halftone generating system having a source of digital data representative of pixel greyscale, a counter to store the digital data, and pulse producing logic responsive to the counter to activate a laser modulator in accordance with the digital data representative of each pixel. In particular, a six bit data word represents one of 64 greyscale states for a particular pixel. The pulse producing logic responds to the particular data word to produce a pulse of a given duration or width to drive the laser for a given time period. The duration of the pulse, representing one to 64 states for a given pixel, will produce a given discrete greyscale value for each pixel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.