Hughes Aircraft Company

Hughes-jvc Technology Corporation

John P Sheppard

John Jeffrey Lyon

Rodney D Sterling

Le Thanh Pham

Robert Baron

Graeme D Gow

William R Peterson

A process for implementing shading corrections in a video projector. The process selects a color to be shaded, and then sets a projector video level at a selected high video level. A target brightness map is then generated for each of a plurality of preselected shading correction application points at the selected high video level. The process sets the projector video level at a selected low video level, and generates a target brightness map for each of the plurality of shading correction application points at the low video level. Actual light levels are then measured at both the high and low video levels for each shading correction application point, and differences between the target and measured brightness values are minimized. The shading process of the present invention is automatically preformed during projector set-up, and thereby eliminates the inherent subjective and time consuming need for conventional manual shading processes.

Automatic shading in an LCLV projector

The photo-sensitive detector region of conventional Impurity Band Conduction (IBC) detector (also known as a Blocked Impurity Band [BIB] detector) is divided into a wide detection (or collection) region and a narrow gain region by means of tailoring the doping profile. The narrow gain region is that portion of the photo-sensitive detector region closest to the blocking layer, where the electric field is the largest, whose As concentration is made smaller (in the range of 2 to 5.times.10.sup.17 cm.sup.-3) to increase the impact ionization coefficient by decreasing the electron scattering. The wide detection region is that portion of the photo-sensitive detector region furthest from the blocking layer, where the electric field is smallest and the As concentration is larger (in the range of 5 to 8.times.10.sup.17 cm.sup.-3) to decrease the impact ionization coefficient by increasing the electron scattering.

Low-noise gain-mode impurity band conduction detector design

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Valley Center, CA, United States of America

John P Sheppard