Gerald H Hooper

US Patent:

40308294, Jun 21, 1977

Filed:

Apr 12, 1976

Appl. No.:

5/676075

Inventors:

Gerald E. Hooper - Los Altos Hills CA

Assignee:

Varian Associates - Palo Alto CA

International Classification:

G01J 342

US Classification:

356 97

Abstract:

In a double beam spectrophotometer employing a rotating optical chopper to direct a beam of electromagnetic radiation alternately through sample and reference channels to a photomultiplier tube, a beam interrupter is used in combination with a photodiode and a photocell to generate a square wave signal having a predetermined temporal relation to the rotation of the optical chopper. The square wave signal is integrated to provide a triangular waveform, whose maxima and minima correspond, respectively, to the passage of the beam through one or the other of the sample and reference channels, and whose cross-over points with respect to a zero reference level correspond to dark intervals during which the beam is blocked from entering either channel. Keying circuitry responsive to the cross-over points provides for detection of dark current generated by the photomultiplier tube, while keying circuitry responsive to the maxima and minima synchronizes analysis circuitry associated with the sample and reference channels with the passing of the beam therethrough and provides for correction of the output of the photomultiplier tube to compensate for dark current.

US Patent:

48859478, Dec 12, 1989

Filed:

Dec 19, 1988

Appl. No.:

7/286612

Inventors:

Valentin Balter - Cupertino CA
Gerald H. Hooper - Soquel CA

Assignee:

Huntington Mechanical Laboratories, Inc. - Mountain View CA

International Classification:

F16J 1550

US Classification:

74 181

Abstract:

A rotary motion feedthrough mechanism for a sealed chamber comprises a first driven shaft (56) with a through opening (66) and a second driven shaft (96) moveably inserted into the through opening of the first shaft. At its rear end the first driven shaft has a recess (102) which is eccentric and inclined with respect to the axis of rotation of both shafts. The recess rotatingly supports one end of a conical sleeve (110), the other end of which is rotatingly supported in an inclined opening of an external sleeve (68) which is connected to a rotary drive unit through a sprocket (76) installed on the outer surface of the external sleeve. The end of the second drive shaft opposite to the eccentric opening of the first shaft is connected to an independent rotary motion feedthrough mechanism which is capable of transmitting rotation into a sealed space. When the mechanism is sealingly connected, e. g. , to a vacuum chamber (46), it can transmit two independent rotations from outside of the chamber (46) to the first and second driven shafts.

US Patent:

40429393, Aug 16, 1977

Filed:

Sep 12, 1975

Appl. No.:

5/612689

Inventors:

William A. Lloyd - San Jose CA
Salvatore Barone - Boulder Creek CA
Gerald E. Hooper - Los Altos Hills CA
Keith E. McFarland - Woodside CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G01D 1528
G03G 1500

US Classification:

346153

Abstract:

Recording machine such as electrostatic printer/plotter or facsimile plotter includes housing construction and associated operating components whereby overall external width reduction is accomplished without loss of function using liftable lid and method of cross-bracing. Machine serviceable through removable bottom closure panel supporting an electronic chassis. Operating stations, such as recording assembly including both electrostatic latent image recording station and a toner developing station, and web-cutting assembly each includes portions in both lid and base of housing to be yieldingly held together in cooperating relation by hinged latching panel in which the hinge pin supplies spring action to urge and retain the latching panel in its detented position.