Method and apparatus for improving the uniformity of an LED printhead
US4982203A · kind A · utility
21Cited by
1References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1989 |
| Grant date | Jan 1, 1991 |
| Priority date | — |
| Expiry date | Jul 7, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K15/1247
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An apparatus and method are provided to correct for the amount of degradation in light output of the light source used with an electrophotographic recording medium of an optical printer. The percentage amount of degradation due to aging is predicted by measuring degradation over a short interval and used to adjust the light output of the individual LEDs by pulse width modulation or current modulation so that there is a uniform light output. Similarly, the percentage amount of degradation due to temperature changes is predicted and used to adjust the light output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.