Color image forming apparatus which reduces toner consumption during image formation
US5646670A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1994 |
| Grant date | Jul 8, 1997 |
| Priority date | — |
| Expiry date | Aug 30, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2215/0074
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A full-color printer which reduces toner consumption by lowering the overall image density without changing the overall image tonality. An invalid data masking unit 31 masks non-printing area of a image signal 39 outputted from a FIFO buffer 30, and outputs the masked image data into a toner-saving image converter 32. The toner-saving image converter 32 zigzag masks the image signal every other pixel in main-scanning and subscanning directions based on a toner-saving mode designation signal A from a CPU 38. The masked image signal density is "00[H]". Thereafter, a .gamma. corrector 35 .gamma. corrects the masked image signal, and a PWM 36 performs pulse-width modulation on the .gamma.-corrected image signal. Image output is made by driving a semiconductor laser 120 with the pulse-width modulated signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.