Exposure control device for electronic endoscope
US5614949A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1995 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Mar 10, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/555
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is provided an electronic shutter control device for an electronic endoscope which can control exposure with high precision even if the intensity of incident light is high in a close-up and the like. The control device has a mask circuit for forming masks having a predetermined width in upper and lower portions of a monitor screen in a vertical scanning direction, and a detection circuit for verifying whether or not the intensity of incident light is higher than a predetermined value. An electronic shutter control circuit forms a discharge pulse for electronic shutter control from a driving pulse generated in a blanking period of a horizontal synchronizing signal when the intensity of incident light is lower than the predetermined value, and forms dense discharge pulses, whose number is, for example, 256 in one horizontal synchronizing signal, in an effective period of the horizontal synchronizing signal in an area masked in the vertical scanning direction when the intensity of incident light is higher than the predetermined value. High-precision exposure control can be achieved in a close-up by controlling the storage charge amount by the sweep control pulses and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.