Light source apparatus using electric lamp as light source
US6320331A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1999 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Dec 10, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B47/20
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A light source apparatus is used in a video endoscope system having a charge coupled device (CCD) image sensor and a monitor. The light source apparatus provides illumination to a scene to be imaged by the CCD image sensor and displayed on the monitor. The light source apparatus includes a discharge lamp serving as a light source. The lamp is subject to progressive degradation during use so that its output light intensity achievable with a given level of input current gradually decreases through its lifetime. The current supplied to the lamp is controlled using a feedback control technique so as to maintain the output light intensity of the lamp at a substantially fixed, desired intensity level. In order to allow the operator to timely replace the discharge lamp with a new one, the input current to the discharge lamp is detected and compared to a threshold level. The threshold level may be selected to a level corresponding to the rated power of the lamp designated by the manufacturer. The input current has a tendency that its level for achieving a given level of output light intensity of the lamp gradually increases through the lifetime of the lamp, which is caused by progressive d…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.