Variable capacitor, position indicator, and input device

A position indicator, comprising:

• an electronic circuit board including a first terminal portion and a second terminal portion,
• a variable capacitor used in conjunction with the electronic circuit board, said variable capacitor including:
• a dielectric having a first surface portion and a second surface portion opposite to said first surface portion, and
• a conductive elastic member shaped as an enclosure defined by a bottom surface and a wall surface intersecting said bottom surface to enclose said dielectric, the enclosure forming a board coupling portion to receive at least a portion of the electronic circuit board therein, and the bottom surface of the enclosure forming a dielectric contacting portion,
• wherein said first terminal portion is coupled to said first surface portion, said second terminal portion is coupled to said board coupling portion, and said dielectric contacting portion is disposed separately from said second surface portion so as to face said second surface portion and is configured to be deformed to come in contact with said second surface portion, and
• a contact area between said second surface portion and said dielectric contacting portion is changed in correspondence to a depressing force, which is applied against said dielectric contacting portion in a direction toward the dielectric, thereby changing an electrostatic capacitance of the variable capacitor;
• and
• a resonance circuit having said variable capacitor.

An input device, comprising:

• a position indicator including a case, an elongated core body accommodated within the case and having one end thereof protruding from said case while having another end thereof accommodated within the case, a variable capacitor whose electrical capacitance changes when an external force is applied thereto through the other end of said core body, and an electronic circuit board having a first terminal portion and a second terminal portion coupled to the variable capacitor;
• and
• a position detector comprising a detection surface configured to detect a position indicated by said one end of the core body protruding from said case,
• wherein said variable capacitor of said position indicator includes a dielectric having a first surface portion and a second surface portion opposite to said first surface portion, and a conductive elastic member shaped as an enclosure defined by a bottom surface and a wall surface intersecting said bottom surface to enclose said dielectric, the enclosure forming a board coupling portion to receive at least a portion of the electronic circuit board therein, and the bottom surface of the enclosure forming a dielectric contacting portion,
• said first terminal portion is coupled to said first surface portion, said second terminal portion is coupled to said board coupling portion, and said dielectric contacting portion is disposed separately from said second surface portion so as to face said second surface portion and is configured to be deformed to come in contact with said second surface portion, and
• a contact area between said second surface portion and said dielectric contacting portion is changed in correspondence to a depressing force, which is applied against said dielectric contacting portion in a direction toward the dielectric through the other end of said core body, thereby changing an electrostatic capacitance of the variable capacitor.