Stylus, handwriting system using the same and operating method thereof

1 . A stylus, comprising:

a pen shaft;

a touchpad, arranged on a part of a surface of the pen shaft for being held by a user;

a memory, configured to record reference information associated with the touchpad; and

a processor, configured to compare current information associated with the touchpad with the reference information to calibrate an offset of a current track of the stylus caused by the user holding at different positions of the touchpad, wherein

the reference information comprises reference raw data outputted by the touchpad in a learning mode, reference object information and reference feature information obtained by processing the reference raw data, and

the current information comprises current raw data outputted by the touchpad in an operating mode, current object information and current feature information obtained by processing the current raw data.

2 . The stylus as claimed in claim 1 , wherein

the reference object information and the current object information respectively comprise at least one of a respective position, a respective angle, a position of center of gravity and an average angle of multiple fingers on the touchpad, and

the reference feature information and the current feature information respectively comprise at least one of a respective size, a holding posture and a number of the multiple fingers on the touchpad.

3 . The stylus as claimed in claim 2 , wherein the processor is further configured to

learn and record an operating feature of a valid user according to the reference feature information, and

perform user identify recognition according to the current feature information and the operating feature of the valid user.

4 . The stylus as claimed in claim 3 , wherein the processor is further configured to

not output information associated with the current track to a post host upon an invalid user being identified in the user identify recognition.

5 . The stylus as claimed in claim 1 , further comprising:

a pen tip, arranged at a front end of the pen shaft; and

an optical navigation device, arranged in the pen tip and configured to detect the current track.

6 . A handwriting system, comprising:

a host, comprising a display to show a cursor track; and

a stylus, coupled with the host and comprising a touchpad, the stylus configured to, record reference information associated with the touchpad,

compare current information associated with the touchpad and the reference information to calculate an angle difference between a reference angle and a current angle that the user holds the stylus, and

output the angle difference, a calibrated angle or a calibrated track to the host to show the calibrated track on the display.

7 . The handwriting system as claimed in claim 6 , wherein

the reference information comprises reference raw data outputted by the touchpad in a learning mode, reference object information and reference feature information obtained by processing the reference raw data, and

the current information comprises current raw data outputted by the touchpad in an operating mode, current object information and current feature information obtained by processing the current raw data.

8 . The handwriting system as claimed in claim 7 , wherein

the reference object information and the current object information respectively comprise at least one of a respective position, a respective angle, a position of center of gravity and an average angle of multiple fingers on the touchpad, and

the reference feature information and the current feature information respectively comprise at least one of a respective size, a holding posture and a number of the multiple fingers on the touchpad.

9 . The handwriting system as claimed in claim 8 , wherein the stylus is further configured to

learn and record an operating feature of a valid user according to the reference feature information, and

perform user identify recognition according to the current feature information and the operating feature of the valid user.

10 . The handwriting system as claimed in claim 9 , wherein the stylus is further configured to

not output the angle difference, the calibrated angle or the calibrated track to the host upon an invalid user being identified in the user identify recognition.

11 . The handwriting system as claimed in claim 9 , wherein the stylus is further configured to

output a hint signal to the host to control the display to show a message of invalid operation upon an invalid user being identified in the user identify recognition.

12 . The handwriting system as claimed in claim 6 , wherein the stylus further comprises:

an optical navigation device, arranged in a pen tip of the stylus and configured to detect a current track of the stylus.

13 . An operating method of a handwriting system, the handwriting system comprising a stylus having a touchpad and a host having a display, the operating method comprising:

entering a learning mode to record reference information associated with the touchpad;

entering an operating mode to acquire current information associated with the touchpad, and to compare the current information and the reference information to generate calibration information; and

outputting the calibration information to the host to show a calibrated track on the display.

14 . The operating method as claimed in claim 13 , wherein

the reference information comprises reference raw data outputted by the touchpad in a learning mode, reference object information and reference feature information obtained by processing the reference raw data, and

the current information comprises current raw data outputted by the touchpad in an operating mode, current object information and current feature information obtained by processing the current raw data.

15 . The operating method as claimed in claim 14 , wherein

the reference object information and the current object information respectively comprise at least one of a respective position, a respective angle, a position of center of gravity and an average angle of multiple fingers on the touchpad, and

the reference feature information and the current feature information respectively comprise at least one of a respective size, a holding posture and a number of the multiple fingers on the touchpad.

16 . The operating method as claimed in claim 15 , further comprising:

learning and recording, by the stylus, an operating feature of a valid user according to the reference feature information, and

performing, by the stylus, user identify recognition according to the current feature information and the operating feature of the valid user.

17 . The operating method as claimed in claim 16 , further comprising:

not outputting information associated with the calibration information by the stylus to the host upon an invalid user being identified in the user identify recognition, or

outputting a hint signal by the stylus to the host to control the display to show a message of invalid operation upon an invalid user being identified in the user identify recognition.

18 . The operating method as claimed in claim 13 , wherein the calibration information comprises an angle difference between a reference angle and a current angle that the user holds the stylus, a calibrated angle or a calibrated track.

19 . A stylus, comprising:

a pen shaft;

a touchpad, arranged on a part of a surface of the pen shaft for being held by a user;

a memory, configured to record reference information associated with the touchpad; and

a processor, configured to compare current information associated with the touchpad with the reference information to calibrate an offset of a current track of the stylus caused by the user holding at different positions of the touchpad, wherein

the processor is configured to

compare the current information and the reference information to calculate an angle difference between a reference angle and a current angle that the user holds the stylus, and

output the angle difference, a calibrated angle or a calibrated track to a post host.