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. 29, 1995
Filed:
Apr. 29, 1994
Wyko Corporation, Tucson, AZ (US);
Abstract
A scanning interferometer that utilizes a DC gear motor instead of a PZT translator in closed-loop configuration with an LVTD position sensor. The DC motor is connected to the scanning mechanism so that a rotational motion of the motor shaft produces a translation along the optical axis of either the sample or the objective of the interferometer. During scanning, the motor is driven by the input of a ramp signal into the system. The closed-loop configuration is such that a constant, or nearly constant voltage is applied to the DC motor to produce a constant-speed scan in response to the ramp input. Any non-linearity in the speed of motion is corrected by an adjustment to the motor voltage. At the completion of the scan, the ramp input is removed and the motor is automatically returned to the starting position to satisfy the closed-loop condition. In order to maintain the image in focus on the sensor over the wide range of scanning, a pair of relay lenses is inserted in the optical path between the interferometer and the light detector.