Key actuating apparatus and key actuation control system

• US 20080083314A1
• Filed: 09/04/2007
• Published: 04/10/2008
• Est. Priority Date: 09/06/2006
• Status: Active Grant

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: Suzuki, Hideo, Hayashi, Yoshinori, Suzuki, Emiko
• Granted Patent: US 7,692,078 B2
• Time in Patent Office: Days
• US Class Current: 84/22
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G10H 1/346 Keys with an arrangement for simulating the feeling of a piano key, e.g. using counterweights, springs, cams
• CPC Class Codes: G10H 2220/311 with controlled tactile or haptic feedback effect; output interfaces therefor
• CPC Class Codes: Y10S 310/80 Piezoelectric polymers, e.g. PVDF

Abstract

In order to realize a small and light key actuating apparatus for actuating a key which is rotatably supported with respect to a frame, a key actuating apparatus (7) is provided which includes a polymer transducer (9) for rotatably moving the key (3) by using a deformation of the transducer, wherein the transducer which is substantially formed in a plate shape includes: a polymer film (15) which is dielectric and made from an elastically deformable polymer material; and a pair of electrodes (17) arranged at both sides of surfaces of the polymer film, and the transducer is deformed corresponding to switching between an application of voltage and a lack of voltage between the electrodes.

Claims

1. A key actuating apparatus which actuates a key rotatably supported with respect to a frame comprising a polymer transducer for rotatably moving the key by using a deformation of the polymer transducer, wherein

the polymer transducer is substantially formed in a plate shape and comprises:

a polymer film which is dielectric and made from an elastically deformable polymer material; and

a pair of electrodes arranged at both sides of surfaces of the polymer film, and

the transducer is deformed corresponding to switching between an application of voltage and a lack of voltage between the electrodes.

2. A key actuating apparatus according to claim 1, further comprising:

a laminated body which comprises the polymer film and the electrodes; and

a plate shaped member which has a higher elasticity than the polymer film, wherein

the laminated body is fixed on at least one of a front surface and a back surface of the plate shaped member.

3. A key actuating apparatus according to claim 1, wherein

the polymer film is formed in a cylindrical shape,

one of the electrodes facing the another electrode while the polymer film is in-between is arranged on a inside surface of the cylindrically formed polymer film, and

the another electrode is arranged on an outside surface of the cylindrically formed polymer film and covers a portion of an outside peripheral.

4. A key actuation control system comprising:

a key actuating apparatus according to claim 1;

a position detection unit detecting a position of the key while rotatably moving;

a control unit actuating the key by controlling the applied voltage between the electrodes in order to cause a reaction force of the polymer transducer in an opposite direction to a rotatably moving operation of the key when the position detection unit detects rotatable movement of the key due to a manual operation.

5. A key actuation control system according to claim 4, wherein

the position detection unit comprises:

the polymer transducer; and

a capacitance measurement portion measuring a capacitance between

the electrodes, and

the control unit controls the applied voltage between the electrodes based on the measured capacitance.