Capturing Hand Motion
A portable electronic device, a digital camera associated with the portable electronic device, and software configured to run on the portable electronic device and to derive handwriting and control information from hand motion of a writing instrument in the vicinity of the digital camera.
1 - 26 . (canceled)
27 . A method comprising
exposing a sensor of a digital camera directly to infrared light received from a writing instrument that is being subjected to hand motion on a writing surface, and
in a device integrated with the digital camera and separate from the writing instrument and writing surface, processing data from the sensor to derive handwriting or control information based on the hand motion.
28 . The method of claim 27 in which the exposing of the sensor includes receiving light that originates from light sources on the writing instrument.
29 . The method of claim 27 in which the exposing of the sensor includes exposing the sensor to a trace or other marking left by the writing instrument.
30 . The method of claim 29 in which the trace or other marking includes ink selected to increase a signal-to-noise ratio of light received by the sensor.
31 . The method of claim 27 in which the exposing of the sensor includes processing of an image of a tip of a writing instrument.
32 . The method of claim 31 in which the tip of the writing instrument is characterized by being of high contrast with the environment in which it is used.
33 . The method of claim 27 in which the sensor is exposed to hand motion occurring at any arbitrary angle.
34 . The method of claim 27 also including
calibrating the digital camera to permit correctly inferring linear hand motions.
35 . The method of claim 27 also including calibrating the processing of data using information derived when the writing instrument is touched to at least three points on the writing surface.
36 . The method of claim 27 also including automatically switching the digital camera from one format to another by coupling the camera, or a device to which it is connected, to another mechanism.
37 . The method of claim 27 also including adjusting a tilt and/or swivel position of the camera for better coverage of a writing surface.
38 . The method of claim 27 in which light sources on the writing instrument are operated to enabling filtering of noise and interference.
39 . The method of claim 27 in which light sources on the writing instrument are sequenced to encode functionality that includes at least one of erasing or biometrics of handwriting.
40 . The method of claim 27 in which there are enough light sources associated with the writing instrument to prevent loss of tracking when one or more of the light sources are blocked.
41 . (canceled)