| 摘要 |
An optical touch sensing system comprises a touch sensor light source to project light above a surface, an optical touch sensor to capture a touch sense signal from a region above said surface, a pen to optically respond to said projected light, and a touch processing system comprising a signal processor. The signal processor identifies a lateral location of the pen on the surface from the optical response. The signal processor comprises a wireless communication system to send a wireless message to the pen, and the pen comprises an electronic controller coupled to a receiver to receive the wireless message from the signal processor. The projected light may be encoded to send the message to the pen. A brightness of the projected light may be modulated to define bright, touch detecting intervals and intervening intervals. The message may be encoded in the bright intervals or in the intervening intervals. The message may comprise an instruction to the pen to perform an action. The instruction may comprise a pen identity instruction. The projected light may define a touch sheet about the surface. |
