Radiant energy – Photocells; circuits and apparatus – Photocell controlled circuit
Reexamination Certificate
1999-11-23
2001-10-02
Le, Que T. (Department: 2878)
Radiant energy
Photocells; circuits and apparatus
Photocell controlled circuit
C250S216000
Reexamination Certificate
active
06297496
ABSTRACT:
BACKGROUND
The present invention relates generally to infrared photodetectors, and more specifically to a new class of photodetectors which comprise passive structures which reduce self-interference from thermal radiation from the device or its surroundings.
The thermal emissivity of a body characterizes the flux of thermal “blackbody” radiation emitted from the body's surfaces. The ability to passively detect and measure such thermal radiation, e.g., through the use of a photodetector, allows detection and analysis of objects at a distance. Such features as temperature and surface condition can be determined in many cases.
Considerable technological difficulties appear in the use of photodetectors sensitive to thermal radiation characteristic of normal environments (roughly 3 to 30 &mgr;m in wavelength). The surfaces of the photodetector and its housing must be cooled well below room temperature, or the thermal radiation emitted by these surfaces will compromise the limiting sensitivity of the photodetector.
SUMMARY OF THE INVENTION
The present invention relates to photodetectors incorporating internal surfaces coated with new thermal emission control media. This allows uncooled operation while retaining high sensitivity to external sources of thermal radiation. The new thermal emission control media comprise photonic media.
REFERENCES:
patent: 4695859 (1987-09-01), Guha et al.
Dodson Brian W.
Fleming James G.
Lin Shawn-Yu
Dodson Brian W.
Le Que T.
Sandia Corporation
LandOfFree
Photodetectors with passive thermal radiation control does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photodetectors with passive thermal radiation control, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photodetectors with passive thermal radiation control will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2605365