Document reading apparatus having photoconductive detector for detecting documents and document edges
US5202556A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1991 |
| Grant date | Apr 13, 1993 |
| Priority date | — |
| Expiry date | Feb 28, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/00755
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A document reading apparatus comprises a light source part for generating a light beam which scans a document being transported to a reading position along a main scan line by a predetermined scan width, a photoconductive part for supplying a signal outputted when illuminated by a light beam from the light source part, the photoconductive part having a plurality of photoconductive elements aligned within a predetermined width parallel to the main scan line, an optical part for focusing a light beam reflected from the document at the reading position into a reduced light beam and for irradiating the reduced light beam to the photoconductive part by an optical width in a direction parallel to the main scan line. The photoconductive elements extend in a direction parallel to the main scan line by a width difference by which the predetermined width of the photoconductive elements is greater than the optical width of the optical part. The photoconductive elements are divided into an image reading group arranged to read image information and a detection group arranged to detect a document and/or a front edge or rear edge of the document.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.