Patent ID: 7548171

Claim:
A printing device including a wireless sensor system usable to sense a position of paper having a predetermined bands printed thereon by a sensed system using predetermined timing data and to transmit a sound signal utilizing audio phrase data to transmit information when the bands are detected, the information being used for reconstructing the position and speed of paper, the wireless sensor system comprising: a plurality of sensor subsystems provided on the printing device, each sensor subsystem including a sensor positioned along a paper path of the printing device and wirelessly transmitting information by transmitting the sound signal on at least one audio frequency that is unique to that sensor subsystem, the at least one audio frequency being generated based on a frequency defined in a frequency look-up table; and a signal processor subsystem that receives the wirelessly transmitted sound signal from the plurality of sensor subsystems and that determines, from time for transmission of the sound signal, a transmission time of the wirelessly transmitted information, wherein the signal processor subsystem determines which of the plurality of sensor subsystems transmitted the information based on the unique audio frequency used to transmit the information and the transmission time of the information, and the signal processor subsystem determines the position and speed of paper based on the timing data and the transmission time of the information for reconstructing the timing data.