Image reading method and image reading apparatus
US6151419A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 27, 1998 |
| Grant date | Nov 21, 2000 |
| Priority date | — |
| Expiry date | Mar 27, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/401
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image reading apparatus includes: a line sensor 5 for converting light from an original into an electric signal; an A/D converting unit 12 for converting the electric signal derived from the line sensor 5 into a digital signal; a white reference storage unit 24 for storing white reference data set before the original is read; a black reference storage unit 22 for storing black reference data set before the original is read; a light-source light amount detecting unit for detecting a light amount of a light source; and a shading correcting unit 13 for shading-correcting an output signal derived from the A/D converting unit 12 with employment of both white reference data corrected by a white reference correction coefficient and the black reference data. As a consequence, the shading corrections can be performed along both a main scanning direction and a sub-scanning direction. Also, an image reading method includes: a) a step for detecting and setting sub-scanning white reference data when white reference data used in a shading correction is set; b) a step for detecting sub-scanning white reference data in each of reading lines; c) a step for setting as a white reference correction…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.