John Michael Sheppard

US Patent:

54573378, Oct 10, 1995

Filed:

Oct 7, 1994

Appl. No.:

8/319751

Inventors:

Robert Baron - Santa Monica CA
Le T. Pham - Ventura CA
John P. Sheppard - Valley Center CA
William R. Peterson - Los Angeles CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H01L 2714
H01L 3100

US Classification:

257439

Abstract:

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.

US Patent:

40249271, May 24, 1977

Filed:

Dec 22, 1975

Appl. No.:

5/643008

Inventors:

John B. Sheppard - Burbank CA

International Classification:

B65H 5910
A62B 114

US Classification:

182 5

Abstract:

A lowering device including a unit which is adapted to slide downwardly at a controlled rate along a rope or other flexible line and which contains a circuitous passage through which the line extends to introduce friction between the line and the unit. In the preferred arrangement, two clamping devices controlled by rotatable collet sleeves are provided at opposite ends of the passage for controllably varying the rate of descent of the unit along the line, and the circuitous passage is formed by a tube contained within a case and surrounded by a mass of resinous plastic material hardened in place. The tube and contained circuitous passage may first be coiled in one direction, and then be coiled in the opposite direction, in a relation preventing twisting of the line as the device moves downwardly therealong.