Image forming apparatus having illumination direction altered for every plurality of readout operations with respect to one original
US5608547A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1994 |
| Grant date | Mar 4, 1997 |
| Priority date | — |
| Expiry date | Apr 19, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/0434
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a shadow process mode, a scanner reads out an original with a first exposure lamp in a first scanning operation. The readout image data is stored in an image memory via an I/O control unit. In the second scanning operation, the scanner reads out the original with a second exposure lamp having an illumination direction different from that of the first exposure lamp. The image data read out in the second scanning operation and the data stored in the image memory are subtracted for each pixel by a subtractor. The difference thereof is compared with a predetermined value in a comparator. The compared result is output to a selector, whereby a desired image data is provided to a printer processing unit via the I/O control unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.