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:
Apr. 04, 2000
Filed:
Mar. 28, 1997
Applicant:
Inventor:
Takahiro Shiozawa, Tokyo, JP;
Assignee:
NEC Corporation, , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ; H01L / ;
U.S. Cl.
CPC ...
310317 ; 31031601 ;
Abstract
This invention provides the easy and consistent displacement control of a piezo-electric actuator for driving the variable wavelength filter used for wavelength multiplexed optical communication, wherein the piezo-electric actuator is controlled once to the initial displacement condition and, thereafter, a driving voltage is applied to the piezo-electric actuator based on the displacement characteristic data stored in a memory circuit for obtaining a desired displacement.