Position pointer, variable capacitor and inputting apparatus

• US 8,913,041 B2
• Filed: 04/02/2010
• Issued: 12/16/2014
• Est. Priority Date: 03/09/2010
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Fukushima, Yasuyuki, Fujitsuka, Hiroyuki
• Primary Examiner(s): HORNER, JONATHAN R
• Application Number:
  US12/753,282
• Publication Number:
  US 20110219892A1
• Time in Patent Office: 1,719 Days
• Field of Search: 178/19.03, 178/19.01, 345/156, 345/179, 361/277, 361/283.2
• US Class Current: 345/179
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A position pointer is disclosed, including a housing, a substantially bar-like rod accommodated in the housing such that one end thereof projects to the outer side of the housing, and a variable capacitor having a capacitance value which varies in response to external force applied thereto through the rod. The variable capacitor includes a dielectric member having a first face portion and a second face portion opposite from the first face portion, a terminal member configured to engage with the first face portion of the dielectric member, an electrode section disposed in an opposing relationship to the second face portion of the dielectric member and including a conductive member having a contact area with the second face portion that varies in response to the external force, and an elastic member configured to bias the conductive member in a direction in which the conductive member is spaced away from the second face portion.

Claims

1. A position pointer, comprising:

a housing;

a rod accommodated in said housing such that one end thereof projects to an outer side of said housing;

a variable capacitor having a capacitance value which varies in response to external force applied thereto through said rod;

a holder configured to house said variable capacitor therein, said variable capacitor including;

a dielectric member having a first face portion and a second face portion opposite from said first face portion,

a terminal member being engaged with said holder and having elasticity to be biased toward said first face portion of said dielectric member to thereby elastically secure said dielectric member within said holder,

an electrode section disposed in an opposing relationship to said second face portion of said dielectric member and including a conductive member having a contact area with said second face portion that varies in response to the external force, and

an elastic member formed of a coil having conductivity and configured to bias said conductive member in a direction in which said conductive member is spaced away from said second face portion; and

a holding member axially movably housed in said holder and configured to secure a proximal end of said rod and to hold said conductive member and said elastic member such that said conductive member is electrically connected to said elastic member.

2. The position pointer according to claim 1, wherein said terminal member is made of metal and has a third face portion for engaging with said first face portion of said dielectric member.

3. The position pointer according to claim 2, wherein a conductive elastic member is sandwiched between said first face portion of said dielectric member and said third face portion of said terminal member.

4. The position pointer according to claim 2, wherein a conductive metal member is sandwiched between said first face portion of said dielectric member and said third face portion of said terminal member.

5. The position pointer according to claim 1, wherein said second face portion of said dielectric member is in a mirror finished state.

7. The position pointer according to claim 1, wherein said conductive member is formed of conductive rubber material.

8. The position pointer according to claim 1, wherein said holding member holds said conductive member with an end of said coil interposed between said conductive member and said holding member.

6. An inputting apparatus, comprising:

a position pointer including a housing, a rod accommodated in said housing such that one end thereof projects to an outer side of said housing, and a variable capacitor having a capacitance value which varies in response to external force applied thereto through said rod; and

a position detection apparatus having a detection face to be pointed to by an end of said rod and being configured to detect a position pointed to by the end of said rod;

said variable capacitor including;

a dielectric member having a first face portion and a second face portion opposite from said first face portion,

a terminal member configured to engage with said first face portion of said dielectric member,

an electrode section disposed in an opposing relationship to said second face portion of said dielectric member and including a conductive member having a contact area with said second face portion that varies in response to the external force, and

an elastic member formed of a coil having conductively and configured to exert spring force to bias said conductive member in a direction in which said conductive member is spaced away from said second face portion; and

said position pointer further including a holding member axially movably arranged in said housing and configured to secure a proximal end of said rod and to hold said conductive member and said elastic member such that said conductive member is electrically connected to said elastic member.

9. The inputting apparatus according to claim 6, wherein said conductive member is formed of conductive rubber material.

10. The inputting apparatus according to claim 6, wherein said holding member holds said conductive member with an end of said coil interposed between said conductive member and said holding member.