Light control system for electronic endoscopes
US6707485B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1999 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | Feb 22, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/555
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a light control system for electronic endoscopes which provides sufficiently bright images during observation of distant objects, allows stable light control during observation of close objects, and prolongs lamp life. The light control system comprises a CCD drive circuit for controlling a CCD, a microcomputer, a diaphragm drive circuit for driving a diaphragm, a lamp voltage control circuit for variably controlling lamp voltage, and a DVP for generating a luminance signal, wherein the diaphragm drive circuit controls the opening of the diaphragm based on the luminance signal received from the DVP and a constant voltage V1 is normally supplied to the lamp, but a larger voltage up to V2 may be supplied on instructions from the microcomputer if the luminance of an image is insufficient even with the diaphragm fully open. In an embodiment with an electronic shutter circuit, a control is performed so that the lamp voltage will be raised similarly up to V2 only when the amount of light is insufficient even with the electronic shutter set at the lowest speed. Thus, the lamp normally lights at low voltage and glows at high voltage only when the long range…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.