Focus adjustable image reading device for calculating a focus position of a source document
US5742326A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1996 |
| Grant date | Apr 21, 1998 |
| Priority date | — |
| Expiry date | Sep 20, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/0404
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image reading device and method for producing a uniformly focused light image on a source document includes a document mount, an imaging device, and a drive assembly for moving at least one of the mounting device and the imaging device in a secondary scanning direction. The image reading device includes a control circuit for establishing multiple designated positions on the source document in the primary scanning direction and in the secondary scanning direction and for calculating the focus position from a signal output from the imaging device for the multiple designated positions. A cam member can be provided to adjust the position of the document mount along the optical axis of the light striking the document, a cam surface of the cam member contacting the document mount.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.