Patent ID: 7889186
Filing Date: 2011-02-15
Classification: G06F

Abstract:
1. A pen input device, comprising: a writing tip capable of performing a writing operation in contact with a writing surface; a movement detection system operable to generate movement data representing changes between successive positions of said writing tip on said writing surface, said movement detection system including a first optical image sensor for capturing successive movement images in response to light returned from said writing surface and for producing movement image data representing said successive movement images and a movement detection engine configured to produce movement data using said movement image data derived from said successive movement images captured using said first optical image sensor; a position detection system operable to determine a position of said writing tip on said writing surface, said position detection system including a second optical image sensor for capturing a position image in response to light returned from said writing surface and for producing position image data representing said position image and a position detection engine configured to produce position data using said position image data derived from said position image captured using said second optical image sensor, said position detection system being configured to determine said position data representing said position of said writing tip on said writing surface using marks made on said writing surface by at least two writing operations as a positional reference, wherein each of said two writing operations includes said writing tip being in contact with said writing surface followed by said writing tip not being in contact with said writing surface; and a controller operable to activate said movement detection system continuously during said writing operation and to activate said position detection system intermittently during said writing operation.