POSITION INDICATOR AND COORDINATE INPUT DEVICE

• US 20090084614A1
• Filed: 09/11/2008
• Published: 04/02/2009
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Fukushima, Yasuyuki, Fujitsuka, Hiroyuki
• Granted Patent: US 8,304,671 B2
• Time in Patent Office: Days
• US Class Current: 178/19.30
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A position indicator includes a case (2), and a rod (3) housed in the case (2). The rod (3) is passed through a cylindrical ferrite core (6) so that its indicating portion (31) (e.g., pen tip) protrudes from an end of the ferrite core (6). A position detecting coil (4) is wound around the periphery of the ferrite core (6). A switch section (5) (e.g., pressure detector) for detecting the pen pressure of the rod (3) is arranged on the other end of the ferrite core (6). An elastic shock-absorbing member (7) is also attached to the other end of the ferrite core (6), so that the shock-absorbing member (7) is fitted between the ferrite core (6) and the switch section (5). Since any impact force applied to the ferrite core (6) and the rod (3) is alleviated by the shock-absorbing member (7), damage to the ferrite core (6) and the rod (3) can be prevented or reduced.

Claims

1. A position indicator comprising:

a case;

a ferrite core held in the case and having a hole;

a rod arranged to pass through the hole of the ferrite core, one end thereof protruding from one end in the axial direction of the ferrite core to the outside of the case to serve as an indicating portion, and the other end thereof protruding from the other end of the ferrite core;

a coil wound around a periphery of the ferrite core; and

a shock-absorbing member engaged with the other end in the axial direction of the ferrite core.

2. The position indicator according to claim 1, wherein the shock-absorbing member is annularly formed to allow the rod to pass therethrough and to allow the other end of the ferrite core to be inserted therein.

3. The position indicator according to claim 1, wherein the shock-absorbing member is made of silicon rubber.

4. The position indicator according to claim 1, wherein the coil is formed by a magnetic-plated wire.

5. The position indicator according to claim 1, wherein the coil is N-fold wound around the periphery of the ferrite core, where N is greater than one.

6. The position indicator according to claim 1, further comprising a switch section housed in the case, wherein the rod protruding from the other end of the ferrite core controls the switch section in response to the pressure applied to the indicating portion protruding from the one end of the ferrite core.

7. A coordinate input device comprising:

a position detecting device having an input surface; and

a position indicator for indicating its coordinates on the input surface of the position detecting device,

wherein the position indicator includes;

a case;

a ferrite core held in the case and having a hole;

a rod arranged to pass through the hole of the ferrite core, one end thereof protruding from one end in the axial direction of the ferrite core to the outside of the case to serve as an indicating portion, and the other end thereof protruding from the other end of the ferrite core;

a coil wound around a periphery of the ferrite core; and

a shock-absorbing member engaged with the other end of the ferrite core.

8. The coordinate input device according to claim 7, wherein the shock-absorbing member is annularly formed to allow the rod to pass therethrough and to allow the other end of the ferrite core to be inserted therein.

9. The coordinate input device according to claim 7, wherein the shock-absorbing member is made of silicon rubber.

10. The coordinate input device according to claim 7, wherein the coil is formed by a magnetic-plated wire.

11. The coordinate input device according to claim 7, wherein the coil is N-fold wound around the periphery of the ferrite core, where N is greater than one.

12. The coordinate input device according to claim 7, further comprising a switch section housed in the case, wherein the rod protruding from the other end of the ferrite core controls the switch section in response to the pressure applied to the indicating portion upon its contact with the input surface of the position detecting device.

13. A method of manufacturing a position indicator comprising:

providing a ferrite core including a hole;

winding a coil around a periphery of the ferrite core;

arranging a shock-absorbing member at a proximal end in the axial direction of the ferrite core;

inserting a rod through the hole of the ferrite core;

enclosing, in a case, the ferrite core on which the coil is wound, the shock-absorbing member, and the rod, such that a distal end of the rod protrudes from a distal end in the axial direction of the ferrite core to the outside of the case to serve as an indicating portion, and that a proximal end of the rod protrudes from the proximal end in the axial direction of the ferrite core.

14. The method of claim 13, wherein the step of arranging a shock-absorbing member at a proximal end of the ferrite core comprises attaching the shock-absorbing member at the proximal end of the ferrite core using a fixing means.

15. The method of claim 13, wherein the shock-absorbing member is made of elastic material.

16. The method of claim 15, wherein the shock-absorbing member is made of silicon rubber.

17. The method of claim 13, wherein the step of winding a coil around a periphery of the ferrite core comprises N-fold winding the coil, wherein N is greater than one.

18. The method of claim 17, wherein the coil is formed by a magnetic-plated wire.

19. The method of claim 13, further comprising providing a switch section within the case, such that the shock-absorbing member is arranged between the proximal end of the ferrite core and the switch sensor.