Focusing for optical print heads
US4893926A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 23, 1987 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | Mar 23, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K15/1247
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A device for generating printed output has an array of point light sources focused onto a photosensitive surface. The array is spaced from the surface substantially at the position of best focus by generating a pattern of activated and unactivated light sources along the array such that a pair of light sources which lead to the creation of an image on the output are separated by a light source which does not lead to the creation of an image. Since the image size grows in width as the focus decreases, the width of the space between images can be used as a focusing gauge, and appropriate adjustments can be made to maximize the width of the space.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.