Keyboard musical instrument equipped with electromagnetic key touch generator for imparting piano key-touch to player

• US 5,783,765 A
• Filed: 07/02/1997
• Issued: 07/21/1998
• Est. Priority Date: 07/02/1997
• Status: Expired due to Term

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: Muramatsu, Shigeru
• Primary Examiner(s): Witkowski, Stanley J.
• Application Number:
  US08/887,176
• Time in Patent Office: 384 Days
• Field of Search: 84/615, 84/626, 84/658, 84/687-690, 84/20-22, 84/115, 84/DIG. 7
• US Class Current: 84/615
• CPC Class Codes: G10H 1/0555 using magnetic or electromagnetic means
• CPC Class Codes: G10H 1/344 Structural association with individual keys electrically operated wind-actuated organs G10B3/22

Abstract

A keyboard musical instrument includes an electromagnetic key touch generator for imparting a piano-like key touch to black/white keys, and the electromagnetic key touch generator has leaf spring members respectively held in contact with the upper surface of the black/white keys for urging the black/white keys toward the end positions and coil springs urging plungers of solenoid-operated key actuators to urge the black/white keys toward the rest positions; the resilient force of each leaf spring member is balanced with the resilient force of the associated coil spring at the rest position of the associated black/white key, and the solenoid-operated key actuator is expected to partially cancel the resilient force of the coil spring so as to build up resistance to the black/white key depressed by a player.

Claims

1. A keyboard musical instrument comprising:

a plurality of keys turnable along trajectories between respective rest positions and respective end positions;

a plurality of key sensors respectively monitoring said plurality of keys, and respectively producing key status signals each representative of current key status of associated one of said plurality of key sensors;

a plurality of first resilient members respectively associated with said plurality of keys so as to urge the associated keys toward said rest positions;

a plurality of second resilient members respectively associated with said plurality of keys so as to urge the associated keys toward said end positions, a first resilient force of each of said plurality of second resilient members being balanced with a second resilient force of associated one of said plurality of first resilient members at the rest position of associated one of said plurality of keys;

a plurality of key actuators generating forces exerted on said plurality of keys, respectively, so as to build up resistances to key motions from said rest positions toward said end positions; and

a controller connected to said plurality of actuators, and responsive to said key status signals so as to change each resistance depending upon said current key status of associated one of said plurality of keys on the trajectory.

2. The keyboard musical instrument as set forth in claim 1, in which said plurality of key sensors detect current positions of the associated keys on said trajectories, respectively, so that said key status signals respectively represent said current positions.

3. The keyboard musical instrument as set forth in claim 2, in which said plurality of key sensors are implemented by strain gauges attached to said plurality of first resilient members.

4. The keyboard musical instrument as set forth in claim 2, in which said controller has a table storing a plurality of sets of key touch data for said plurality of keys, and each set of key touch data represents a resistance to be applied to associated one of said plurality of keys,

said resistance being variable depending upon the current position of associated one of said plurality of keys.

5. The keyboard musical instrument as set forth in claim 1, in which each of said plurality of key actuators is implemented by a solenoid-operated key actuator having a plunger held in contact with associated one of said plurality of keys.

6. The keyboard musical instrument as set forth in claim 5, in which said solenoid-operated key actuator has a first solenoid coil and a second solenoid coil,

said first solenoid coil urging said plunger in a direction where said associated one of said plurality of keys is moved from said rest position toward said end position,

said second solenoid coil urging said plunger in a direction where said associated one of said plurality of keys is moved from said end portion toward said rest position.

7. The keyboard musical instrument as set forth in claim 6, in which said controller further includes a controlling circuit responsive to music data codes so as to selectively energize the first solenoid coil of said plurality of key actuators and the second solenoid coils of said plurality of key actuators, thereby moving said plurality of keys for reproducing a performance without a fingering on said plurality of keys.

8. The keyboard musical instrument as set forth in claim 5, in which said solenoid-operated key actuator has a single solenoid coil, and said single solenoid coil urges said plunger in a direction where said associated one of said plurality of keys is moved from said rest position toward said end position.

9. The keyboard musical instrument as set forth in claim 5, in which each of said plurality of first resilient members is implemented by a coil spring held in contact with associated one of said plurality of keys at a leading end thereof for urging said plunger in a direction where said associated one of said plurality of keys is moved from said end position toward said rest position, and each of said plurality of second resilient members is implemented by a leaf spring member urging said associated one of said plurality of keys in a direction from said rest position toward said end position.

10. The keyboard musical instrument as set forth in claim 9, in which each of said plurality of first resilient members is implemented by a first leaf spring member held in contact with one end of said plunger for urging said plunger in a direction where associated one of said plurality of keys is moved from said end position toward said rest position, and

each of said plurality of second resilient members is implemented by a second leaf spring member held in contact with the other end of said plunger for urging said plunger in a direction where said associated one of said plurality of keys is moved from said rest position toward said end position.