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:
Aug. 06, 1996
Filed:
Jan. 06, 1995
David W Abraham, Ossining, NY (US);
Danny C Wong, Ringwood, NJ (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Apparatus and method for measuring a change in the height of a surface or the distance between two surfaces. The invention involves converging a light beam having a beam axis and a focus onto the said surface; scanning the focus of the light beam across the surface along the beam axis using a scanning means; measuring intensity of light reflected from the surface during the scanning; determining a maximum of the light intensity; assigning to the maximum of the light intensity a position of the scanning means; repeating these steps to monitor a change in the position of the scanning means assigned to the maximum of the light intensity; and correlating such change in the position of the scanning means to a change in the height of the surface.