Pointer, position detection apparatus and position detection method

• US 10,429,955 B2
• Filed: 03/22/2018
• Issued: 10/01/2019
• 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:
  US15/928,978
• Publication Number:
  US 20180210568A1
• Time in Patent Office: 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, the pen-shaped position indicator comprising:

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

at least three electrodes arranged at the pen-tip portion for transmitting signals, wherein one of the at least three electrodes is arranged on an axis of the pen-tip portion and another one of the at least three electrodes is arranged off the axis of the pen-tip portion;

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

2. The pen-shaped position indicator according to claim 1, wherein at least two of the at least three electrodes are arranged off the axis of the pen-tip portion to surround the one electrode arranged on the axis of the pen-tip portion.

3. The pen-shaped position indicator according to claim 1, wherein at least two of the at least three electrodes are arranged to surround the one electrode arranged on the axis of the pen-tip portion.

4. The pen-shaped position indicator according to claim 1, wherein the pen-tip portion includes conductive material and forms the one electrode arranged on the axis of the pen-tip portion.

5. The pen-shaped position indicator according to claim 1, wherein the signals transmitted from the at least three electrodes are distinguishable from each other.

6. The pen-shaped position indicator according to claim 5, wherein the signals are different in signal-type from each other.

7. The pen-shaped position indicator according to claim 5, wherein the signals are of the same signal-type but have a time difference from each other.

8. The pen-shaped position indicator according to claim 1, wherein the signals are transmitted from the at least three electrodes simultaneously.

9. A method of detecting angular information of a pen-shaped position indicator including a pen-shaped body having a pen-tip portion and at least three electrodes arranged at the pen-tip portion, the method comprising:

transmitting signals from the at least three electrodes, wherein one of the at least three electrodes is arranged on an axis of the pen-tip portion and another one of the at least three electrodes is arranged off the axis of the pen-tip portion,

forming capacitive relationships between a sensor surface and the at least three electrodes transmitting the signals, respectively, to generate detection signals in the sensor surface, from which a first detection signal, a second detection signal, and a third detection signal distinguishable from each other are extracted, and

using the first detection signal, the second detection signal, and the third detection signal to obtain angular information of the pen-shaped position indicator.

10. The method according to claim 9, wherein at least two of the at least three electrodes are arranged off the axis of the pen-tip portion to surround the one electrode arranged on the axis of the pen-tip portion.

11. The method according to claim 9, wherein at least two of the at least three electrodes are arranged to surround the one electrode arranged on the axis of the pen-tip portion.

12. The method according to claim 9, wherein the signals transmitted from the at least three electrodes are distinguishable from each other.

13. The method according to claim 12, wherein the signals are different in signal-type from each other.

14. The method according to claim 12, wherein the signals are of the same signal-type but have a time difference from each other.

15. The method according to claim 9, wherein the signals are transmitted from the at least three electrodes simultaneously.

16. A pen-shaped position indicator configured to capacitively couple with a sensor surface, the pen-shaped position indicator comprising:

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

at least three electrodes arranged at the pen-tip portion for transmitting signals, wherein one of the at least three electrodes is arranged on an axis of the pen-tip portion and another one of the at least three electrodes is arranged off the axis of the pen-tip portion;

wherein the at least three electrodes transmitting signals form capacitive relationships with a sensor surface, respectively, to generate detection signals in the sensor surface, from which a first detection signal, a second detection signal, and a third detection signal distinguishable from each other are extracted, and relative positions of the first, second, and third detection signals are used to obtain angular information of the pen-shaped position indicator.

17. The pen-shaped position indicator according to claim 16, wherein the angular information is one or more of a first rotational angle of the pen-shaped position indicator about its axis, an inclination angle of the pen-shaped position indicator relative to the sensor surface, and a second rotational angle of the pen-shaped position indicator relative to the sensor surface.

18. The pen-shaped position indicator according to claim 16, wherein the detection signals are sensed at least at two different positions in the sensor surface.

19. The pen-shaped position indicator according to claim 18, wherein the detection signals of the at least three electrodes are sensed at at least three different positions in the sensor surface, respectively.

20. The pen-shaped position indicator according to claim 16, wherein the at least three electrodes transmit signals that are distinguishable from each other.

21. A signal processing device, used with a pen-shaped position indicator having a pen-tip portion and at least a first electrode arranged at a first position of the pen-tip portion and a second electrode arranged at a second position of the pen-tip portion different from the first position in a longitudinal direction, wherein the first electrode and the second electrode form capacitive relationships with a sensor array coupled to the signal processing device, the sensor array forming a sensor surface and including first electrodes extending in a first direction and second electrodes extending in a second direction different from the first direction, the signal processing device configured to:

detect a first position pointed to by the pen-shaped position indicator on the sensor surface based on a first capacitive relationship between the first electrode of the pen-shaped position indicator from which a first transmission signal is transmitted and the first and second electrodes of the sensor array,

sense signal levels of signals, based on a second capacitive relationship between the second electrode of the pen-shaped position indicator from which a second transmission signal is transmitted and the first and second electrodes of the sensor array that are located adjacent to the first position, and

determine a tilt angle of the pen-shaped position indicator against the sensor surface of the sensor array based on the first position and comparison of the signal levels of the signals sensed from the first and second electrodes of the sensor array that are located adjacent to the first position.

22. The signal processing device according to claim 21, which is capable of distinguishing the first transmission signal from the first electrode from the second transmission signal from the second electrode of the pen-shaped position indicator.

23. The signal processing device according to claim 22, wherein the first transmission signal from the first electrode and the second transmission signal from the second electrode are different in signal-type from each other.

24. The signal processing device according to claim 22, wherein the first transmission signal from the first electrode and the second transmission signal from the second electrode are of the same signal-type but have a time difference from each other.

25. The signal processing device according to claim 22, wherein the first transmission signal and the second transmission signal are simultaneously transmitted from the first electrode and the second electrode, respectively.

26. A signal processing device, used with a pen-shaped position indicator having a pen-tip portion and at least a first electrode arranged at a first position of the pen-tip portion and a second electrode arranged at a second position of the pen-tip portion different from the first position in a longitudinal direction, wherein the second electrode is off an axis of the pen-tip portion and consists of segmented electrode pieces, wherein the first electrode and the second electrode form capacitive relationships with a sensor array coupled to the signal processing device, the sensor array forming a sensor surface and including first electrodes extending in a first direction and second electrodes extending in a second direction different from the first direction, the signal processing device configured to:

detect a first position pointed to by the pen-shaped position indicator on the sensor surface based on a first capacitive relationship between the first electrode of the pen-shaped position indicator from which a first transmission signal is transmitted and the first and second electrodes of the sensor array,

sense signal levels of signals, based on a second capacitive relationship between the segmented electrode pieces of the second electrode from which a second transmission signal is transmitted and the first and second electrodes of the sensor array that are located adjacent to the first position, and

determine a rotation angle of the pen-shaped position indicator on the sensor surface of the sensor array based on the first position and comparison of change in the signal levels of the signals sensed from the first and second electrodes of the sensor array that are located adjacent to the first position.