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. 25, 2000
Filed:
May. 05, 1998
Karl Arthur Flechsig, Los Gatos, CA (US);
Donald Edward Horne, San Jose, CA (US);
Sylvia Lui Lee, San Jose, CA (US);
Walter Gerald Woodworth, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A glide height test signal processor and method using increased high frequency components is disclosed. The processor is more sensitive to smaller asperities, maintains the positive characteristics of being monotonic and can be easily calibrated. The system includes a circuit for converting asperity contact to an electrical signal, a first bandpass circuit coupled to the first circuit, the first bandpass circuit having a first amplifier for amplifying the electrical signal by a first gain to generate a first amplified signal and a first filter for filtering the first amplified signal at a high frequency to generate a first filtered signal, wherein the first gain is selected for detection of asperities having a diameter of less than or equal to five microns and a processing circuit, coupled to the first bandpass circuit, for processing the first filtered signal to generate an indication of contact with an asperity having a diameter of less than or equal to five microns. A second bandpass circuit may be coupled to the first circuit, wherein the second bandpass circuit has a second amplifier for amplifying the electrical signal by a second gain to generate a second amplified signal and a second filter for filtering the second amplified signal at a low frequency to generate a second filtered signal, wherein the ratio of the first gain and the second gain is substantially at least thirty to one.