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. 24, 2011
Filed:
Mar. 03, 2009
Applicant:
Nariyasu Yaguchi, Hamamatsu, JP;
Inventor:
Nariyasu Yaguchi, Hamamatsu, JP;
Assignee:
Yamaha Corporation, Hamamatsu-shi, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G10C 3/12 (2006.01);
U.S. Cl.
CPC ...
Abstract
In order to detect a state of a key, a differential acceleration sensoris provided in addition to a common position sensorand a velocity sensor. A reaction force applied by a solenoid unitis determined on the basis of a function which monotonously increases with respect to a differential acceleration signal j in an initial period which is an early stage of depression of a key. After a lapse of the initial period, the reaction force is determined in accordance with velocity, acceleration and the like, referring to a table. As a result, the reaction force rises up rapidly when a key is depressed strongly.