Method and apparatus for sensing activity for a keyboard and the like

• US 4,649,784 A
• Filed: 01/31/1985
• Issued: 03/17/1987
• Est. Priority Date: 01/31/1985
• Status: Expired due to Fees

• Current Assignee: Robert G. Fulks
• Original Assignee: Robert G. Fulks
• Inventors: Fulks, Robert G., Hager, Robert J.
• Primary Examiner(s): Witkowski, S. J.
• Assistant Examiner(s): Warren, David
• Application Number:
  US06/696,693
• Time in Patent Office: 775 Days
• Field of Search: 84/DIG. 7, 84/1.27, 84/1.1, 84/433-435, 338/69, 338/47, 338/114, 338/80
• US Class Current: 84/690
• CPC Class Codes: G10H 1/0556 using piezoelectric means
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 2201/036 Variable resistance
• CPC Class Codes: Y10S 84/07 Electric key switch structure

Abstract

Apparatus and method for the monitoring of the manipulation of the keys of an instrument comprises monitoring apparatus which takes the form of a pressure sensing device, associated with each key, that can be fabricated in a configuration compatible with the instrument. According to one embodiment, the pressure sensing devices can be arranged so that the monitoring apparatus can be positioned on a balance rail of a piano keyboard. In this embodiment, the monitoring configuration can be fabricated and conveniently retrofitted to a standard keyboard. The pressure sensing device comprises a resistive element, a conducting element, and a force transducer ink layer separating the resistive and conducting elements. The resistance of the resistive element is monitored and when pressure is applied to the pressure sensing device, a change in resistance can be measured. Because the resistance is a function of pressure, the amount of pressure used to activate the key can be determined.

Claims

1. Apparatus for determining activity of a musical instrument comprising:

a keyboard, said keyboard comprising a plurality of keys and a balance rail supporting said keys; and

a pressure sensing device associated with each of said keys, said pressure sensing device providing a change in resistance when said associated key has a force applied thereto,

said pressure sensing device is positioned between said keys and said balance rail.

2. The apparatus for determining activity of a musical instrument of claim 1 wherein said change in resistance is determined by the force applied to said associated key.

3. The apparatus for determining activity of a musical instrument of claim 1 wherein said pressure sensing device comprises:

a resistive element;

a conductive element; and

a layer of force transducer ink position between said resistive element and said conductive element.

4. Apparatus for determining activity of a musical instrument of claim 1 further including means for distributing a force between each said key and said balance rail more uniformly over said associated pressure sensing device.

5. Apparatus for determining activity of a musical instrument of claim 4 wherein a plurality of said pressure sensing devices can be positioned on a keyboard monitoring means, said monitoring means being positioned on said balance rail.

6. The method of detecting motion of a key of a musical instrument, said musical instrument comprising a keyboard having a plurality of keys positioned on a balance rail, said method comprising the steps of:

p1 positioning a pressure sensing device on said balance rail to be activated upon manipulation of at least one of said keys, said pressure sensing device comprising a planar resistive element, a planar conducting element, and a layer of force transducer ink between said conducting element and said resistive element; and

detecting a change in resistance of said pressure sensing device when said at least one key is manipulated.