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:
Nov. 23, 1999
Filed:
May. 07, 1997
Shanlin Hao, Eden Prairie, MN (US);
Ray V Rigles, Eden Prairie, MN (US);
William P Wood, Edina, MN (US);
Lars H Ahlen, Eagan, MN (US);
John C Heitke, Burnsville, MN (US);
Seagate Technology, Inc., Scotts Valley, CA (US);
Abstract
A lapping system data acquisition unit is disclosed for use in measuring resistances of multiple resistors embedded in a structure to be machined. Each of multiple independent current sources directs a current through one of the multiple resistors embedded in the structure during machining of a surface of the structure. Each of multiple voltage sensing devices couples to a separate one of the multiple resistors and provides a separate analog voltage output signal indicative of the resistance of the resistor. Each of multiple filters is coupled to a separate one of the multiple voltage sensing devices Analog-to-digital conversion circuitry coupled to the multiple filters generates a digitized signal for each of the filtered output signals.