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:
Jun. 14, 2011
Filed:
Mar. 09, 2010
Tomoya Sasaki, Hamamatsu, JP;
Tomoya Sasaki, Hamamatsu, JP;
Yamaha Corporation, Shizuoka-Ken, JP;
Abstract
An upright piano is equipped with a soft pedal, and a player makes the hammer stroke shorter by depressing the soft pedal; while a user is reproducing a music tune by means of an automatic player piano fabricated on the basis of the upright piano, the keys are servo controlled on the basis of a position difference of keys between target values and actual values and a key velocity difference, and the duty ratio of driving signal, which is supplied to solenoid-operated key actuators for the keys, are determined on the basis of multiplications between the position difference/key velocity difference and a position gain and a velocity gain; the value of position gain is reduced on the condition that the soft pedal is depressed for preventing the playback from an unintentional loud tone or tones.