Document image reading device
US6515774B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2002 |
| Grant date | Feb 4, 2003 |
| Priority date | — |
| Expiry date | May 16, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04734
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A document-image reading device that can analyze a speed fluctuation state of a scanner when scanning an image in the feed direction by separately extracting speed fluctuation components by reading a change in density of reference scale lines and, on the basis of the analysis result, prevents the occurrence of an image blur that may be resulting from unstable factors of a driving mechanism. The document-image reading device for reading a document image data at a specified time-interval given by the reference clock signal, which comprises an image sensor for reading a document image by moving the image sensor or the document in the feed direction and is featured in that the document-image reading device is further provided with a chart reader for reading a reference chart portion having alternations of a high-density division and a low-density division arranged one after another at a distance-interval equal to a least pitch readable by the document-image reading device along the feed direction and a processor for processing image data read from the reference chart portion by using a comb-type filter and by integration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.