Adjustment of dot size for laser imagers
US5793406A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1996 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Mar 6, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4076
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Fine pulse width modulation (PWM) adjustments in the output of a laser printer are accomplished by receiving values from a bit map and modifying the values in accordance with values in a lookup table (LUT). The lookup table is subdivided into a plurality of blocks, and a selection of the blocks is made in accordance with external values. This allows the output of a pulse width modulation circuit to be adjusted to a precision that is greater than that afforded by the bit size of the values from the bit map. The use of plural blocks in the lookup table permits adjustments in the output of the pulse width modulation circuit in accordance with external factors such as relative humidity, sensitivity of an optical photoreceptor, and developer life.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.