Laser printer having means for changing the output-image size
US4651170A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1985 |
| Grant date | Mar 17, 1987 |
| Priority date | — |
| Expiry date | Apr 2, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/393
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A laser printer is disclosed which uses a rotating polygon and a cylindrical mirror disposed between the polygon and an image zone. The cylindrical mirror corrects for pyramidal errors in an output image formed on a moving photosensitive member disposed at the image zone by making the operative polygon facet and the image zone optically conjugate in the page scan direction. To change the length of the image in the line scan direction at the image zone, the distance between the polygon and image zone is varied. This is accomplished by moving the cylindrical mirror or by positioning a different cylindrical mirror at a new optical path position. The velocity of the photosensitive member is adjusted to change the length of the output image in the page scan direction. The tilt angle of the cylindrical mirror moved to the new optical path position is changed or the cylindrical mirror is removed from the path and a different cylindrical mirror is inserted at a new optical path position. In either case, at the new image format size, the cylindrical mirror makes the operative polygon facet optically conjugate with the image zone in the page scan direction to correct for pyramidal errors. An…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.