Digital AGC circuit for image processing
US5650784A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 1995 |
| Grant date | Jul 22, 1997 |
| Priority date | — |
| Expiry date | Jan 4, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/52
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Before actually reading a document image, white reference data corresponding to a pure white document image is found in an AGC processing unit 32, and is set in a register 32a. In a CPU 33, data corresponding to the white reference data set in the register 32a is produced. The produced data is set in a register 32b. The set data is applied to a D/A converting unit 34, where the data is converted into analog data, after which the analog data is applied as a low reference voltage V.sub.ref L to an A/D converting unit 31. As a result, the maximum amplitude range of the analog image data becomes approximately the same as the input voltage range. Accordingly, AGC processing can be realized in a digital manner, thereby to make it possible to simplify the circuit arrangement, as compared with the conventional circuit arrangement, and to easily make fine adjustment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.