Document overlap-detecting apparatus and process
US4160546A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1977 |
| Grant date | Jul 10, 1979 |
| Priority date | — |
| Expiry date | Dec 23, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65H2701/1912
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
An apparatus and process for detecting overlapped documents in a document processing apparatus by detecting the translucency of the documents. The disclosed apparatus includes a transport path for guiding documents and drive wheels for moving the documents along the transport path. Four LED (light source) phototransistor (light detector) pairs are located across the transport path. One LED-phototransistor pair is used together with electronics to detect when a document is present. Two LED-phototransistor pairs are used together with edge detection electronics to detect sudden significant changes in document translucency from the immediately previous translucency of the same document as the documents pass thereby. The other LED phototransistor pair is used together with level detect electronics to sample and hold the translucency level at the beginning of each document, and then to detect when the present translucency level of the document exceeds predetermined guardbands on either side of the translucency level at the beginning of the document as the documents pass thereby. Overlap indicating electronics indicates overlapped documents when the outputs of the two edge detects and th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.