Method and device for deriving pen position and reporting pen position to host computer

1. A method performed by a device, which is coupled to a touch surface on which a pen indicates a position, and which is coupled to a host computer, the method comprising:

securing a buffer area in a memory of the device for retaining a plurality of reports;

deriving a pen position on the touch surface based on signals received by the device from the touch surface and/or from the pen at each determined scanning time;

for each derived pen position, generating a report including a first area including position data indicating the derived pen position and a second area including at least a pen pressure value, to thereby generate and store the plurality of reports in the buffer area;

and

sequentially transmitting the plurality of reports to the host computer and, in response to detecting a pen-up event indicating that the pen is separated from the touch surface, modifying one or more of the pen pressure values included in one or more of the plurality of reports that have not been transmitted, and transmitting the one or more of the plurality of reports including the modified one or more of the pen pressure values to the host computer.

2. The method according to claim 1 , wherein

the second area includes non-position data which is static data which does not change per each scanning time.

3. The method according to claim 2 , wherein the static data includes one or more of a pen ID for identifying the pen, a vendor identification for identifying a vendor of the pen, a color set to the pen by a user, or a pen type indicating a kind of the pen.

4. The method according to claim 2 , wherein the pen is configured to transmit the static data to the device in response to detection of contact of the pen with the touch surface.

5. The method according to claim 1 , wherein

the second area includes non-position data which is less-frequent data which is obtained less frequently than the position data.

6. The method according to claim 1 , wherein the modifying of a pen pressure value includes reducing the pen pressure value.

7. A touch controller configured to be coupled to a touch surface on which a pen indicates a position and to be coupled to a host computer, the touch controller comprising:

a memory including a buffer area for retaining a plurality of reports; and

processing circuitry coupled to the memory and configured to:

derive a pen position on the touch surface based on signals received by the touch controller from the touch surface and/or from the pen at each determined scanning time;

for each derived position, generate a report including a first area including position data indicating the derived pen position and a second area including at least a pen pressure value, to thereby generate and store the plurality of reports in the buffer area;

and

sequentially transmit the plurality of reports to the host computer and, in response to detecting a pen-up event indicating that the pen is separated from the touch surface, modify one or more of the pen pressure values included in one or more of the plurality of reports that have not been transmitted, and transmit the one or more of the plurality of reports including the modified one or more of the pen pressure values to the host computer.

8. A method performed by a device, which is coupled to a touch surface on which a pen indicates a position, and which is coupled to a host computer, the method comprising:

deriving a pen position on the touch surface based on signals received by the device from the touch surface and/or from the pen at each determined scanning time;

for each derived pen position, generating a report including a first area including position data indicating the derived pen position and a second area including a pen pressure value indicating a pressure applied to a pen tip of the pen, to thereby generate a plurality of reports; and

sequentially transmitting the plurality of reports to the host computer and, in response to detecting a pen-up event indicating that the pen is separated from the touch surface, rewriting one or more of the pen pressure values included in one or more of the plurality of reports that have not been transmitted, and transmitting the one or more of the plurality of reports including the rewritten one or more of the pen pressure values to the host computer.

9. The method according to claim 8 , wherein the device detects the pen-up event according to a change in the pen pressure value received from the pen to zero or less.

10. The method according to claim 8 , wherein the one or more of the plurality of reports that have not been transmitted are one or more of the plurality of reports that have not been generated at a time of the detection of the pen-up event.

11. The method according to claim 10 , wherein the special processing includes rewriting a pen pressure value in a report generated immediately after the detection of the pen-up event to a value higher than zero.

12. The method according to claim 8 , wherein the one or more of the plurality of reports that have not been transmitted are one or more of the plurality of reports that have been generated at a time of the detection of the pen-up event.

13. The method according to claim 12 , wherein a pen pressure value in a report generated immediately after the detection of the pen-up event is not rewritten.

14. A touch controller configured to be coupled to a touch surface on which a pen indicates a position and to be coupled to a host computer, the touch controller comprising:

a memory including a buffer area for retaining a plurality of reports; and

processing circuitry coupled to the memory and configured to:

derive a pen position on the touch surface based on signals received by the touch controller from the touch surface and/or from the pen at each determined scanning time;

for each derived position, generate a report including a first area including position data indicating the derived pen position and a second area including a pen pressure value indicating a pressure applied to a pen tip of the pen, to thereby generate the plurality of reports; and

sequentially transmit the plurality of reports to the host computer and, in response to detecting a pen-up event indicating that the pen is separated from the touch surface, rewrite one or more of the pen pressure values included in one or more of the plurality of reports that have not been transmitted, and transmit the one or more of the plurality of reports including the rewritten one or more of the pen pressure values to the host computer.