Position indicator and coordinate input device

• US 8,304,671 B2
• Filed: 09/11/2008
• Issued: 11/06/2012
• 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
• Primary Examiner(s): Nguyen, Kevin M
• Assistant Examiner(s): Lee, Jr., Kenneth B
• Application Number:
  US12/209,165
• Publication Number:
  US 20090084614A1
• Time in Patent Office: 1,517 Days
• Field of Search: 345/179, 178/19.03, 178/19.06, 178/18.06, 178/18.07, 178/43, 178/64
• US Class Current: 178/19.03
• 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 position indicator 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 pressure detector housed in the case;

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

a rod arranged to pass through the hole of the ferrite core, a distal end thereof protruding from a distal end in the axial direction of the ferrite core to the outside of the case to serve as a position indicating portion, and a proximal end thereof protruding from a proximal end of the ferrite core and being positioned and configured to press upon the pressure detector when a pressure is applied to the position indicating portion of the rod;

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

a shock-absorbing member formed of elastic material and engaged between the proximal end of the ferrite core and the pressure detector to elastically couple the ferrite core with the pressure detector and so as to alleviate an external impact applied to the case from being transmitted to the ferrite core;

wherein the pressure detector is configured to detect the pressure applied to the position indicating portion of the rod; and

wherein the shock-absorbing member comprises a first cylindrical portion that connects with the proximal end of the ferrite core and a second cylindrical portion that connects with the pressure detector, an inner diameter of the first cylindrical portion is substantially equal to an outer diameter of the ferrite core, and the pressure detector includes a first mating portion and the second cylindrical portion includes a second mating portion that is configured to engage with the first mating portion.

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

3. 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.

11. The position indicator according to claim 1, wherein the first mating portion of the pressure detector is an opening having an inner diameter that is substantially equal to an outer diameter of the second cylindrical portion of the shock-absorbing member.

4. 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 pressure detector housed in the case;

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

a rod arranged to pass through the hole of the ferrite core, a distal end thereof protruding from a distal end in the axial direction of the ferrite core to the outside of the case to serve as a position indicating portion, and a proximal end thereof protruding from a proximal end of the ferrite core and being positioned and configured to press upon the pressure detector when a pressure is applied to the position indicating portion of the rod;

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

a shock-absorbing member formed of elastic material and engaged between the proximal end of the ferrite core and the pressure detector to elastically couple the ferrite core with the pressure detector and so as to alleviate an external impact applied to the case from being transmitted to the ferrite core;

wherein the shock-absorbing member comprises a first cylindrical portion that connects with the proximal end of the ferrite core and a second cylindrical portion that connects with the pressure detector, an inner diameter of the first cylindrical portion is substantially equal to an outer diameter of the ferrite core, and the pressure detector includes a first mating portion and the second cylindrical portion includes a second mating portion that is configured to engage with the first mating portion.

5. The coordinate input device according to claim 4, wherein the coil is formed by a magnetic-plated wire.

6. The coordinate input device according to claim 4, 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 4, wherein the first mating portion of the pressure detector is an opening having an inner diameter that is substantially equal to an outer diameter of the second cylindrical portion of the shock-absorbing member.

7. 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;

providing a pressure detector;

arranging a shock-absorbing member formed of elastic material at a proximal end in the axial direction of the ferrite core to elastically couple the ferrite core with the pressure detector;

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, the pressure detector, 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 a position indicating portion, and that a proximal end of the rod protrudes from the proximal end in the axial direction of the ferrite core, wherein the proximal end is positioned and configured to press upon the pressure detector when a pressure is applied to the position indicating portion of the rod and wherein the pressure detector is configured to detect the pressure applied to the position indicating portion of the rod;

wherein the shock-absorbing member comprises a first cylindrical portion that connects with the proximal end of the ferrite core and a second cylindrical portion that connects with the pressure detector, an inner diameter of the first cylindrical portion is substantially equal to an outer diameter of the ferrite core, and the pressure detector includes a first mating portion and the second cylindrical portion includes a second mating portion that is configured to engage with the first mating portion.

8. The method of claim 7, wherein the first mating portion of the pressure detector is an opening having an inner diameter that is substantially equal to an outer diameter of the second cylindrical portion of the shock-absorbing member.

9. The method of claim 7, 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.

10. The method of claim 9, wherein the coil is formed by a magnetic-plated wire.