Robert E Sparks

US Patent:

40537803, Oct 11, 1977

Filed:

Oct 20, 1975

Appl. No.:

5/623861

Inventors:

Robert A. Sparks - Palo Alto CA

Assignee:

Syntex (U.S.A.) Inc. - Palo Alto CA

International Classification:

G01N 2300

US Classification:

250445T

Abstract:

The method of calibrating an axial tomographic scanner including frame means having an opening therein in which an object to be examined is to be placed, source and detector means mounted on the frame means for directing one or more beams of penetrating radiation through the object from the source to the detector means, and means to rotate the scanner including the source and detector means about the object whereby a plurality of sets of data corresponding to the transmission or absorption by the object of a plurality of beams of penetrating radiation are collected; the calibration method comprising mounting calibration means supporting an adjustable centering member onto the frame means, positioning the adjustable centering member at approximately the center of rotation of the scanner, placing position-sensitive indicator means adjacent the approximately centered member, rotating the scanner and the calibration means mounted thereon at least one time and, if necessary, adjusting the positioning of the centering member until the centering member is coincident with the center of rotation of the scanner as determined by minimum deflection of the position-sensitive indicator means, rotating and translating the source and detector means and determining for each angular orientation of the frame means supporting the source and detector means (a) the central position of each translational scan relative to the centered member and/or (b) if a plurality of detectors are utilized with the detector means for each planar slice of the object being examined, the central position of each translational scan for each detector relative to the centered member.

US Patent:

43520219, Sep 28, 1982

Filed:

Jan 7, 1980

Appl. No.:

6/109877

Inventors:

Douglas P. Boyd - Woodside CA
William B. Herrmannsfeldt - Los Altos CA
James R. Quinn - San Jose CA
Robert A. Sparks - Palo Alto CA

Assignee:

The Regents of the University of California - Berkeley CA

International Classification:

A61B 600
H01J 3500

US Classification:

378 12

Abstract:

A high speed multiple section, computed-tomographic x-ray scanner is provided. The scanner utilizes a multiple-anode, scanning electron beam x-ray source to provide high speed scanning of sections of the body. No mechanical motion is involved.

US Patent:

40769810, Feb 28, 1978

Filed:

Jul 29, 1976

Appl. No.:

5/709691

Inventors:

Robert A. Sparks - Palo Alto CA
George B. Rothbart - Menlo Park CA
Roger N. Samdahl - San Jose CA

Assignee:

Syntex (U.S.A.) Inc. - Palo Alto CA

International Classification:

G01M 2320

US Classification:

250272

Abstract:

A position sensitive detector including a curved detector housing having a hollow detector chamber therein, the housing having an elongate opening in the curved side wall thereof and an x-ray transmissive material adjacent thereto to render the detector chamber air-tight, a back cathode plane comprising a plurality of spaced cathode conductors on an insulator support and at least one curved anode wire, extending at least substantially transverse to the back cathode plane, disposed within the detector chamber in the path of x-rays entering through the elongate opening. Each anode wire, which is mechanically supported only at the ends thereof, is caused, during operation of the detector, to be supported in planar arcuate form solely by electrostatic forces. During operation of the detector, the chamber is filled with an ionizable gas and voltage is applied to the curved anode wire(s), thereby enabling detection of ionizing events occuring within the detector chamber. The detector is particularly adapted to use with x-ray diffractometers, particularly of the powder type, but is also adapted for use with single crystal x-ray diffractometers and x-ray cameras.

US Patent:

47906944, Dec 13, 1988

Filed:

Oct 9, 1986

Appl. No.:

6/916779

Inventors:

John W. Wilent - San Jose CA
Robert F. Benson - San Jose CA
Robert A. Sparks - Palo Alto CA

Assignee:

Loma Park Associates - Campbell CA

International Classification:

B23C 300

US Classification:

408 1R

Abstract:

A method and apparatus for optimizing the drilling position of a multi-layer printed circuit board prior to drilling. A template having precisely located target holes and fixture reference marks provides initial coordinate reference information for multi-layer printed circuit boards to be inspected by x radiation. Each board is processed by insertion into a holding fixture, examination of four quadrant target areas using x-ray sources and detectors, digitization of the target area images in each quadrant, and computaton of the optimum board position in a follow-on drilling apparatus. After optimization, three reference holes are punched along one edge of the board to provide accurate fiducial positioning marks when the board is placed in the drilling apparatus.