Image reading apparatus with adjusting lines of image data taken
US6867885B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 2000 |
| Grant date | Mar 15, 2005 |
| Priority date | — |
| Expiry date | Jul 11, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/407
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image reading apparatus includes a photoelectric transducer which reads an image of a document and outputs an analog image signal, an A/D converter which converts the analog signal to a digital image signal, and an offset level detecting circuit which determines an average value of output levels from picture elements in a predetermined range of the photoelectric transducer. Further, there is an offset setting unit which provides an offset in the analog image signal before the A/D conversion on the basis of the average value, a first comparing device which compares the average value to a predetermined target value, and an adjusting device which adjusts a size of the predetermined range of the photoelectric transducer on the basis of the result of the comparison.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.