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. 06, 1999
Filed:
Dec. 22, 1997
John C Tsai, Saratoga, CA (US);
Mervyn I Hopson, Cupertino, CA (US);
Excel Precision, Inc., Santa Clara, CA (US);
Abstract
An environmental metrology device (10) containing sensor (12) elements which include a pressure sensor (20), a temperature sensor (22), and a humidity sensor (24) all located in close proximity within a housing (18). Control circuitry (16) is further provided to direct operation of the sensors (12) and to communicate with an interferometer controller (42) via a signal port (14) and a cable (92). Additional instances of the device (10) may be connected in a daisy-chain network configuration via additional signal ports (14) and cables (90). One or more instances of the device (10) permit highly localized characterization of atmospheric index of refraction in the measurement region (60) of a laser interferometer (30). The interferometer controller (42) is thereby able to compensate measurements performed by the laser interferometer (30) before they are passed onto manufacturing process controls (48).