Device and method for maintaining image scanner data output rate without regard to scanline length while maintaining a constant integration time
US5687009A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1995 |
| Grant date | Nov 11, 1997 |
| Priority date | — |
| Expiry date | Sep 28, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40056
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for varying a scanline rate of a digital scanner while maintaining a constant integration period. The scanner scans a scanline of an image, integrates an array of photosensors after a first predetermined period of time has elapsed and after a second predetermined period of time has elapsed. One of the predetermined periods is equal to an integration period of the array of photosensors, and the other period is equal to a difference between a time needed to process a scanline of image data and the integration period of the array of photosensors. The scanner produces a scanline of valid image data and a scanline of image data corresponding to the first scanned scanline. The scanner then scans the next scanline of the image. By having a variable dummy or garbage integration period in conjunction with the analog image unit's constant rated integration period to form the scanline period, a scanner can utilize a variable scanline period while maintaining a constant integration period and a synchronous scanning operation so as to capitalize on the increase efficiency of new photosensors and faster microprocessors and other processing circuitry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.