Position pointer and signal processor

1. A position pointer including a pen-shaped housing and configured to point to a position on a sensor, which is coupled to a position detector, based on capacitive coupling between the position pointer and the sensor, the position pointer comprising:

a first electrode arranged to extend from one axial end of the pen-shaped housing;

a second electrode arranged adjacent to the first electrode to surround an axis of the pen-shaped housing;

a signal generation circuit configured to generate a first signal and a second signal which are distinguishable from each other;

a signal supply control circuit configured to selectively supply the first signal and the second signal generated by the signal generation circuit to the first electrode and the second electrode; and

a control signal reception circuit configured to receive a control signal transmitted from the position detector, the control signal being configured to control operation of the signal supply control circuit; wherein

the signal supply control circuit, in response to the control signal received by the control signal reception circuit,

operates in a first operation mode, in which information to identify the position pointer is transmitted from the position pointer to the position detector, and the first signal and the second signal are controllably supplied to the first electrode and the second electrode, to thereby controllably transmit the first signal and the second signal from the first electrode and the second electrode to the sensor, and

operates in a second operation mode, in which at least the information to identify the position pointer is transmitted from the position pointer to the position detector.

2. The position pointer of claim 1 , wherein the first signal is supplied to the first electrode and the second signal is supplied to the second electrode.

3. The position pointer of claim 2 , wherein the first signal and the second signal are time-overlapped with each other.

4. The position pointer of claim 2 , wherein the first signal and the second signal are time-divisionally transmitted to the sensor.

5. The position pointer of claim 4 , wherein the first signal and the second signal have the same frequency.

6. The position pointer of claim 1 , wherein the control signal reception circuit receives the control signal based on the capacitive coupling between the position pointer and the sensor coupled to the position detector.

7. The position pointer of claim 1 , wherein the control signal reception circuit receives the control signal via a wireless signal transmitted from the position detector.

8. The position pointer of claim 1 , further comprising:

a signal transmission circuit configured to transmit a signal to the position detector wirelessly, and

a pressure detection circuit configured to detect a pressure applied to the first electrode,

wherein a pressure signal detected by the pressure detection circuit is transmitted by the signal transmission circuit to the position detector wirelessly.

9. The position pointer of claim 1 , further comprising:

a signal transmission circuit configured to transmit a signal to the position detector wirelessly,

wherein the information to identify the position pointer is transmitted by the signal transmission circuit to the position detector wirelessly.

10. A position detector that is coupled with a sensor and configured to detect a position pointed to by a position pointer on a sensor surface of the sensor, based on capacitive coupling between the sensor and the position pointer,

wherein the position pointer includes a pen-shaped housing, a first electrode arranged to extend from one axial end of the pen-shaped housing and configured to be capacitively coupled with the sensor, a second electrode arranged adjacent to the first electrode to surround an axis of the pen-shaped housing and configured to be capacitively coupled with the sensor, and a signal generation circuit configured to generate a first signal and a second signal which are distinguishable from each other,

the position detector comprising:

a control signal transmission circuit configured to transmit a control signal to the position pointer, the control signal configured to set the position pointer in a first operation mode, in which information identifying the position pointer is transmitted from the position pointer to the position detector, and the first signal and the second signal are selectively supplied to the first electrode and the second electrode of the position pointer, and set the position pointer in a second operation mode in which at least the information identifying the position pointer is transmitted from the position pointer to the position detector; and

a detection circuit configured to detect the first signal and the second signal, and to detect the information identifying the position pointer, in response to the control signal, wherein the detection circuit is configured to acquire angle information of the position pointer relative to the sensor surface based on the first and second signals detected by the sensor.

11. The position detector of claim 10 , wherein the detected signals have different frequencies from each other.

12. A position detector that is coupled with a sensor and configured to detect a position pointed to by a position pointer on a sensor surface of the sensor, based on capacitive coupling between the sensor and the position pointer,

wherein the position pointer includes a pen-shaped housing, a first electrode arranged to extend from one axial end of the pen-shaped housing and configured to be capacitively coupled with the sensor, a second electrode arranged adjacent to the first electrode to surround an axis of the pen-shaped housing and configured to be capacitively coupled with the sensor, and a signal generation circuit configured to generate a first signal and a second signal which are distinguishable from each other,

the position detector comprising:

a control signal transmission circuit configured to transmit a control signal to the position pointer, the control signal configured to control the position pointer to selectively supply the first signal and the second signal to the first electrode and the second electrode of the position pointer and to control the position pointer to transmit information identifying the position pointer to the position detector; and

a detection circuit configured to detect the first signal and the second signal, and to detect the information identifying the position pointer, in response to the control signal, wherein the detection circuit is configured to acquire angle information of the position pointer relative to the sensor surface based on the first and second signals detected by the sensor.

13. The position detector of claim 12 , wherein the detected signals have the same frequency.