Pixel density variable image apparatus
US4862289A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1987 |
| Grant date | Aug 29, 1989 |
| Priority date | — |
| Expiry date | Nov 30, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A laser printer includes an optical scanning system for scanning a laser beam carrying image information to be written across a photosensitive member repetitively to thereby write an image on the photosensitive member. In the present laser printer, the frequency of a pixel clock is varied in accordance with the pixel density or line speed, thereby maintaining the light intensity of the laser beam in each pixel substantially at constant. Preferably, the optical scanning system includes a first optical system leading a laser beam emitted from a laser to a rotating polygon mirror and a second optical system for leading the laser beam deflected by the polygon mirror to a photosensitive drum, whereby a first light path defined by the first optical system and a second light path defined by the second optical system cross each other at different elevations at least partly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.