Imaging apparatus
US5694448A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 12, 1996 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | Jul 12, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/73
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In imaging apparatus particularly for use in intra-oral dental applications, a solid state imager is continually clocked out during a wait period prior to irradiation from an X-ray source. A signal derived from the CCD is compared with a threshold at to determine the onset of irradiation by the X-ray source which will appear as a rapid change in the signal level. The threshold conditions are varied to follow changes in ambient conditions and particularly temperature changes to allow for increase of dark current with a rise in temperature. This permits the threshold at which the CCD is triggered to begin image acquisition to be set at a relatively low level whilst minimising the risk of false triggering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.