Laser pattern generator
US6731320B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1999 |
| Grant date | May 4, 2004 |
| Priority date | — |
| Expiry date | Mar 19, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/704
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A scanning system uses a multi-beam brush having a widely separated beams, a modulator that controls intensity of pixels in scan beams, an optical system that minimizes scan line bow at the expense of non-uniform scanning beam velocity, and a timing generator that generates a pixel clock signal having a variable period that compensates for the non-uniformity of pixel velocity. The wide separation of scan beams permits the modulator to turn beams on or off with a direction of brightening or darkening in the cross-section of the beams being opposite to the scanning direction. A novel arrangement of the beams in the brush permits a uniform indexing step size to uniformly expose an image region. In one embodiment, the timing generator includes: a source of pixel period values; a select circuit to select pixel period values for pixels, and a counter that loads a first value from the pixel period value selected for a pixel, counts for a period of time indicated by the first value, and asserts a signal marking an end of the period. An additional delay after the signal from the counter can be shorter than the period of a clock signal to the counter but also controlled by the pixel period v…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.