| PENANDFREE CO., LTD. Patent applications |
| Patent application number | Title | Published |
|---|
| 20120105314 | METHOD AND SYSTEM FOR INPUTTING INFORMATION USING ULTRASONIC SIGNALS - Provided are an information input system and an information input method using an ultrasonic signal. In the information input system or method, a signal generation apparatus for generating a reference signal and an ultrasonic signal or an information input apparatus for generating a reference signal receives a reference signal and an ultrasonic signal which are generated by a different signal generation apparatus which inputs information in an adjacent area or the information input apparatus, determines whether or not there is a possibility of interference of the signals generated by the different signal generation apparatus or the information input apparatus, and adaptively changes an effective section where the reference signal and the ultrasonic signal are generated to an idle section in the same period or the next period if it is determined that there is a possibility of the interference, so that the signal interference is prevented. Therefore, even in the environment where a plurality of the information input systems are present, it is possible to stably input information. | 05-03-2012 |
| 20090257315 | POSITION TRACING SIGNAL GENERATOR UNIT AND INPUT SYSTEM HAVING THE SAME - Disclosed are a position tracing signal generator unit and an input system using the same. The position tracing signal generator unit of the present invention generates ultrasonic signals with a constant time interval to allow ultrasonic signals generated from a plurality of ultrasonic signal generator to be overlapped and amplified. It is possible to increase the intensity of the ultrasonic signal and lengthen the range. Due to the structural advantages of the present invention as described above, it is possible to solve a problem of the prior art, i.e., a large thickness of the position tracing signal generator unit caused by a large size of the ultrasonic sensor for increasing the intensity of the ultrasonic signal. | 10-15-2009 |
