Patents by Inventor Francis J. Ehret

Francis J. Ehret has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method for automatically identifying semiconductor wafers
    Patent number: 4585931
    Abstract: A technique for automatically identifying a semiconductor wafer (30) having bar code identification indicia (32) on the front surface (31) thereof. Reading of the code is achieved by rotating the wafer about an axis (34) perpendicular to its front surface (31); directing a beam of radiant energy (37) at the code (32) along a predetermined direction relative to the front surface (31); and sensing, while rotating the wafer, the reflected radiant energy (39) within a second predetermined angular direction relative to the front surface. The bar code used herein is preferably a modified or "stretched" bar code 39 formed on the front surface of the wafer, and having an aspect ratio (i.e., dimension of a space/dimension of a bar) ranging from 1 to 4 (FIG. 2).
    Type: Grant
    Filed: November 21, 1983
    Date of Patent: April 29, 1986
    Assignee: AT&T Technologies, Inc.
    Inventors: Hibbert A. Duncan, Francis J. Ehret, Sherwin R. Kahn, Karen H. Kinney, Peter D. Parry