The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 18, 2000
Filed:
Apr. 02, 1997
Yervant D Lepejian, Palo Alto, CA (US);
Lawrence A Kraus, San Jose, CA (US);
Julie D Segal, Palo Alto, CA (US);
John M Caywood, Sunnyvale, CA (US);
Credence Systems Corporation, Fremont, CA (US);
Abstract
Apparatus for supplying a signal after a predetermined time delay comprises circuitry for generating a base delay signal that is synchronized to a stable master oscillator insensitive to changes in at least one environmental variable. A vernier signal delay circuit provides delay increments smaller than those available from the base delay signal, the delay increments being sensitive to said at least one environmental variable. Storage circuitry is provided for storing information related to the duration of the delay increments as function of at least one environmental variable for which correction is to be supplied. Sensing circuitry is provided for sensing the at least one environmental variable for which correction is to be provided to supply a sensed at least one environmental variable. Control signal generating circuitry is provided, responsive to the sensing means and cooperating with the storage means, for generating a control signal to the vernier signal delay means to select a desired delay from among the delay increments in response to the sensed at least one environmental variable.