Color-adjusted camera light and method
US6488390B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 2001 |
| Grant date | Dec 3, 2002 |
| Priority date | — |
| Expiry date | Oct 16, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S362/802
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Improved method and apparatus for hand-held portable illumination. A flashlight and corresponding method are described. The flashlight includes a housing, a plurality of LEDs, and an electrical circuit that selectively applies power from the DC voltage source to the LED units, wherein the flashlight is suitable for handheld portable operation by a user. In one embodiment, the first electrical circuit further includes a control circuit for maintaining a predetermined light output level of the LED units as a charge on a battery varies. In another embodiment, the control circuit maintains an average predetermined light output level of the LED units as the charge on the battery cell varies by changing a pulse width or frequency as the charge on the battery cell varies to maintain a given average light output. Another aspect provides an illumination source that includes a light-emitting diode (LED) housing including one or more LEDs, and a control circuit that selectively applies power from a source of electric power to the LEDs, the control circuit substantially maintaining a light output characteristic of the LEDs as a voltage of the voltage source varies over a range that would other…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.