Pointer, position detection apparatus and position detection method

• US 10,423,247 B2
• Filed: 11/13/2017
• Issued: 09/24/2019
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Oda, Yasuo, Yamamoto, Sadao, Sugiyama, Yoshihisa
• Primary Examiner(s): Lu, William
• Application Number:
  US15/811,233
• Publication Number:
  US 20180067570A1
• Time in Patent Office: 680 Days
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A position detection apparatus of the electrostatic coupling type is provided, to detect not only a position of a pointer but also information other than the position information such as, for example, pointer pressure or side switch information. The pointer transmits two codes such that a pressure applied to a pen tip is associated with a time difference between the two codes. A position detector carries out a correlation matching operation between signals generated in reception conductors and correlation calculation codes corresponding to the two codes, to thereby detect a position on a sensor section pointed to by the pointer from a result of the correlation matching operation and based on at least one of the codes. The position detector further includes a pressure calculation circuit for detecting pressure applied to the pointer, which is associated with the time difference between the two codes, from the result of the correlation matching operation calculated by the correlation matching operation and based on the two codes.

Claims

1. A pen-shaped position indicator configured to capacitively couple with a sensor surface including a matrix of conductors, the pen-shaped position indicator comprising:

a pen-shaped body having a pen-tip portion;

a first electrode arranged at a first position of the pen-tip portion;

a second electrode arranged at a second position of the pen-tip portion different from the first position;

a pressure sensor configured to sense a pressure applied to the first electrode; and

a signal production circuit configured to generate first and second signals that are distinguishable from each other, the pressure sensed by the pressure sensor being encoded in at least one of the first and second signals, and the first and second signals being respectively supplied to the first and second electrodes;

wherein the first and second electrodes are configured to form first and second capacitive relationships with the sensor surface, respectively, to generate detection signals in the sensor surface from which a first detection signal and a second detection signal distinguishable from each other are extracted and used to obtain a position, angle information, and the pressure of the pen-shaped position indicator.

2. The pen-shaped position indicator according to claim 1, wherein the first and second electrodes are arranged at the first and second positions that are different along an axis of the pen-shaped position indicator.

3. The pen-shaped position indicator according to claim 1, wherein the second electrode is arranged to surround the first electrode.

4. The pen-shaped position indicator according to claim 1, wherein the second electrode comprises plural electrode pieces arranged to surround the first electrode.

5. The pen-shaped position indicator according to claim 1, wherein the first and second signals are different in type from each other.

6. The pen-shaped position indicator according to claim 1, wherein the first and second signals are of the same type but have a time difference from each other.

7. A pen-shaped position indicator configured to capacitively couple with a sensor surface including a matrix of conductors, the pen-shaped position indicator comprising:

a pen-shaped body having a pen-tip portion;

a first electrode arranged at a first position of the pen-tip portion;

a second electrode arranged at a second position of the pen-tip portion different from the first position;

a pressure sensor configured to sense a pressure applied to the pen-tip portion; and

a signal production circuit configured to generate first and second signals that are distinguishable from each other, the pressure sensed by the pressure sensor being encoded in at least one of the first and second signals, and the first and second signals being respectively supplied to the first and second electrodes;

wherein the first and second electrodes are configured to form first and second capacitive relationships with the sensor surface, respectively, to generate detection signals in the sensor surface from which a first detection signal and a second detection signal distinguishable from each other are extracted and used to obtain a position, angle information, and the pressure of the pen-shaped position indicator.

8. The pen-shaped position indicator according to claim 7, wherein the pen-tip portion includes conductive material and forms the first electrode.

9. The pen-shaped position indicator according to claim 7, wherein the first and second electrodes are arranged at the first and second positions that are different along an axis of the pen-shaped position indicator.

10. The pen-shaped position indicator according to claim 7, wherein the second electrode is arranged to surround the first electrode.

11. The pen-shaped position indicator according to claim 7, wherein the second electrode comprises plural electrode pieces arranged to surround the first electrode.

12. The pen-shaped position indicator according to claim 7, wherein the first and second signals are different in type from each other.

13. The pen-shaped position indicator according to claim 7, wherein the first and second signals are of the same type but have a time difference from each other.

14. A method of detecting a pen pressure, a position, and angle information of a pen-shaped position indicator relative to a sensor surface including a matrix of conductors, the method comprising:

providing the pen-shaped position indicator including;

i) a pen-shaped body having a pen-tip portion;

ii) a first electrode arranged at a first position of the pen-tip portion; and

iii) a second electrode arranged at a second position of the pen-tip portion different from the first position;

sensing a pressure applied to the first electrode from the sensor surface;

generating first and second signals that are distinguishable from each other;

encoding the pressure in at least one of the first and second signals;

supplying the first and second signals to the first and second electrodes, respectively;

forming first and second capacitive relationships between the first and second electrodes with the sensor surface, respectively, to generate detection signals in the sensor surface from which a first detection signal and a second detection signal distinguishable from each other are extracted; and

using the first detection signal and the second detection signal to obtain a position, angle information, and the pressure of the pen-shaped position indicator.

15. The method according to claim 14, wherein the first and second electrodes are arranged at the first and second positions that are different along an axis of the pen-shaped position indicator.

16. The method according to claim 14, wherein the second electrode is arranged to surround the first electrode.

17. The method according to claim 14, wherein the second electrode comprises plural electrode pieces arranged to surround the first electrode.

18. The method according to claim 14, wherein the first and second signals are different in type from each other.

19. The method according to claim 14, wherein the first and second signals are of the same type but have a time difference from each other.