Thomas R Guthrie

US Patent:

6348805, Feb 19, 2002

Filed:

Mar 10, 1999

Appl. No.:

09/265666

Inventors:

William E. Jackson - Mission Viejo CA
Thomas L. Guthrie - Placentia CA

Assignee:

Mania-Barco GmbH - Gent

International Classification:

G01R 3102

US Classification:

324758, 324754, 716 12, 716 13

Abstract:

A process for creating a pin assignment for a test fixture for electronic circuits is disclosed. A difficulty rating is determined for each test point on an electronic circuit. The difficult areas are assigned the pins on a test grid, with the difficulty rating of adjacent test points being iteratively determined as the process continues. If a pin cannot be assigned because of conflicts, one or more adjacent test points are reassigned pins, with the difficulty matrix being recalculated with each change and with pins being reassessed and reassigned. When all test points are assigned a pin, the pins are checked to see if they interfere with each other, and further iterations may result.

US Patent:

49911155, Feb 5, 1991

Filed:

May 16, 1989

Appl. No.:

7/352562

Inventors:

Thomas L. Guthrie - Huntington Beach CA
Paul K. Stephenson - Anaheim CA

Assignee:

Excellon Industries, Inc. - Torrance CA

International Classification:

G06K 1500

US Classification:

364520

Abstract:

A method for generating mask transparencies for the mass production of printed circuit boards using a laser photoplotting system includes an algorithm for mapping geometric entities from the continuous plane such as is used in vector photoplotting to a pixel graphic representation of the geometric entities. The method reduces offset errors between rectangular entities and circular entities in phototool primitives constructed in the discrete pixel graphic system by selecting a pixel to represent the corner of the rectangular entity that is closest to the circumference of the circular entity.