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:
Sep. 08, 1998
Filed:
Nov. 25, 1996
Applicant:
Inventors:
Jun Yamamoto, Hamamatsu, JP;
Tsutomu Sasaki, Hamamatsu, JP;
Assignee:
Yamaha Corporation, Shizuoka-ken, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06M / ; G01D / ;
U.S. Cl.
CPC ...
250221 ; 250229 ; 341 31 ; 200332 ;
Abstract
A position transducer determines a current key position through variation of light intensity interrupted by a shutter plate attached to a key, and a semi-column shaped convex lens elongates the light beam radiated from an optical fiber in a direction parallel to the trajectory of the key so that the light beam fully covers the motion of the shutter plate.