Extended dynamic range image digitizing apparatus
US5343308A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 12, 1991 |
| Grant date | Aug 30, 1994 |
| Priority date | — |
| Expiry date | Apr 12, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/028
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The extended dynamic range image digitizing apparatus digitizes image-containing media with dynamic ranges that significantly exceed the dynamic range of the low-cost solid-state light detectors that are customarily used in such equipment. The essence of the invention is the incorporation of controllable light attenuators means in the light path from light source to light detectors thereby permitting the light emerging from an image pixel to be matched to the available dynamic range of the light detector. The pixel light sensed by the detector is controlled in any one of a number of ways. One way is to control the intensity of the light source. A second way which is appropriate for certain types of light detectors is to apply a gating signal to the detector which controls the period of time that the detector is sensitive to incident light. A third way is to interpose an electronic or mechanical shutter mechanism with a controllable open-shutter time in the light path. And finally, a fourth way is to replicate either the light source or detector associated with a particular pixel and interpose fixed different-level light attenuators in the different light paths thereby created.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.