Document detection device and a copying machine provided with the document detection device
US5453818A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1994 |
| Grant date | Sep 26, 1995 |
| Priority date | — |
| Expiry date | Jul 1, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/607
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
After placing an original document on a document platen of a copying apparatus main body, when a detection switch detects a predetermined angle of .theta. of a document cover in the course of closing the document cover, a light-emitting device of a distance-measuring sensor is driven. Light released from the light-emitting device is projected onto the original document or the document cover, and the reflected light is received by a light-receiving device. A signal corresponding to the light-receipt point of the light-receiving device is released, and a measurement is made to find the distance from the sensor to the original document or to the document cover based on the signal. A discrimination is made as to the presence or absence of original document based on the measured distance, and copying control suitable for the result of the discrimination is carried out. At this time, if external light or other light is received by the light-receiving device, the output of the light-receiving device exceeds a predetermined range. This state is regarded as no original document is located above the related distance-measuring sensor, and the corresponding process is carried out.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.