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:
May. 08, 2001
Filed:
Sep. 14, 1999
Applicant:
Inventors:
Tomoyuki Ura, Shizuoka, JP;
Tsutomu Sasaki, Shizuoka, JP;
Assignee:
Yamaha Corporation, Hamamatsu, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G10G 3/04 ;
U.S. Cl.
CPC ...
G10G 3/04 ;
Abstract
An automatic player piano is equipped with a position detecting device for detecting current positions of the black/white keys, and the position detecting device radiates light beams across the trajectories of the black/white keys, wherein the position detecting device stores a variable relation between a relative value of the amount of light and the current positions for determining the current positions so that the position detecting device keeps the reliability of the current positions against aged deterioration.