Variable capacity condenser and pointer

• US 6,853,369 B2
• Filed: 04/19/2001
• Issued: 02/08/2005
• Est. Priority Date: 05/08/2000
• Status: Expired

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Fukushima, Yasuyuki, Fujitsuka, Hiroyuki
• Primary Examiner(s): Chow, Dennis-Doon
• Assistant Examiner(s): Kumar, Srilakshmi K.
• Application Number:
  US09/837,368
• Publication Number:
  US 20010038384A1
• Time in Patent Office: 1,391 Days
• Field of Search: 345/179, 178/19.04, 178/18, 738/626.9, 737/18, 361/283, 361/280, 361/283.1, 361/283.2, 361/287, 361/291, 333/66, 340/689
• US Class Current: 345/179
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: H01G 5/0136 with movable electrodes
• CPC Class Codes: H01G 5/014 Housing; Encapsulation
• CPC Class Codes: H01G 5/16 using variation of distance between electrodes

Abstract

The present invention provides a variable capacity condenser having fewer components. A variable capacity condenser according to the present invention comprises a dielectric substance, two electrodes, and a flexible electrode. The dielectric substance has two end faces. The two electrodes are disposed on one end face of the dielectric substance. The flexible electrode faces the other end face of the dielectric substance. The flexible electrode is pressible by a pressing member to vary a distance between at least a portion of the flexible electrode and the other end face of the dielectric substance.

Claims

1. A variable capacity condenser comprising;

a dielectric substance of an electric pointer device having two end faces;

two electrodes disposed on one end face of the dielectric substance; and

a flexible electrode facing the other end face of the dielectric substance and pressible by a pressing member to vary a distance between at least a portion of the flexible electrode and the other end face of the dielectric substance.

2. The variable capacity condenser according to claim 1, wherein the flexible electrode comprises a mixture of rubber and conductive particles.

3. The variable capacity condenser according to claim 2, wherein the conductive particles are carbon particles.

4. The variable capacity condenser according to claim 1, wherein the flexible electrode is a deposition film.

5. The variable capacity condenser according to claim 1, further comprising an elastic member positioned between the flexible electrode and the pressing member.

6. The variable capacity condenser according claim 1, further comprising a spacer positioned between the other end face of the dielectric substance and the flexible electrode.

7. A pointer comprising:

a casing;

a circuit disposed within the casing, the circuit including a variable capacity condenser comprising;

a dielectric substance having two end faces;

two electrodes disposed on one end face of the dielectric substance; and

a flexible electrode facing the other end face of the dielectric substance; and

a pressing member to press the flexible electrode of the variable capacity condenser to vary a distance between at least a portion of the flexible electrode and the other end face of the dielectric substance.

8. The pointer according to claim 7, wherein the flexible electrode of the variable capacity condenser comprises a mixture of rubber and conductive particles.

9. The pointer according to claim 8, wherein the conductive particles are carbon particles.

10. The pointer according to claim 7, wherein the flexible electrode of the variable capacity condenser is a deposition film.

11. The pointer according to claim 7, wherein the variable capacity condenser further comprises an elastic member positioned between the flexible electrode and the pressing member.

12. The pointer according claim 7, wherein the variable capacity condenser further comprises a spacer positioned between the other end face of the dielectric substance and the flexible electrode.

13. The pointer according to claim 7, wherein the casing is pen-shaped and the pointer includes a core having a pen point protruding outside the casing to transmit pressure applied thereto to the variable capacity condenser.

14. The pointer according to claim 13, wherein the pressing member is a ferrite core made integral with the core and having a coil wound therearound.

15. The pointer according to claim 13, wherein the pressing member is the core slidable through a ferrite core having a coil wound therearound.

16. The pointer according to claim 7, further comprising a circuit substrate having front and back sides, each of the front and back sides including at least a portion of the circuit printed thereon, the at least a portion of the circuit printed on the front side including a conducting portion electrically connected to one of the two electrodes and the at least a portion of the circuit printed on the back side including a conducting portion electrically connected to the other of the two electrodes.

17. The pointer according to claim 16, the conducting portions are soldered to the two electrodes.

18. The pointer according to claim 16, wherein the conducting portions are provided around an end face of the circuit substrate abutting the one end face of the dielectric substance at a portion separating the two electrodes by a predetermined distance.

19. The pointer according to claim 18, wherein the circuit substrate has a thickness substantially equal to the predetermined distance of the portion of the dielectric substance separating the two electrodes.