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. 21, 1991
Filed:
Jan. 19, 1990
Wayne L Stahnke, Los Angeles, CA (US);
Other;
Abstract
There is disclosed a method and apparatus for reproducing in a player piano the pedal mechanism movements which approximate those of the original performance from a tape or other recording medium on which has been recorded data representative of the sequential positions of the piano pedal mechanisms during the original performance. A playback mechanism reads the desired pedal positions from a digitally encoded tape, and this is converted to an analog voltage representative of the desired pedal position. The voltage is then differentiated as a function of time to produce a voltage that is representative of the velocity of the pedal mechanism. A velocity sensor in the form of a permanent magnet within a coil senses the movement of the pedal mechanism in the reproducing piano to create a second signal proportional to the actual velocity of the pedal mechanism. These two signals are compared and applied through an operational amplifier to the solenoid which moves the pedal mechanism in the player piano, thereby approximating the movement of the pedal mechanism during the recorded performance.