| 摘要 |
Detection is achieved by a recognizable pattern being applied to the surface of the roller over which documents pass. The optical document reader comprises a reading head (1) for analysis of successive lines of the document (10), associated with a counter-roller (2) supporting the document from the opposite side. Circuits detect the front edge of the document, and control a mechanism (2,4,5,6) which drives the document towards the reading head. The counter roller (2) includes a particular optical design on its surface, and when this is detected by the optical detector this is taken as an indication that the document has passed out of the reading position, and the drive mechanism is stopped. The optical pattern may be provided by a region of reflective material, or two bands around the roller in a distinctive pattern.
|
