| 摘要 |
A position detecting device that can accurately detect and input the coordinate position of a stylus without being affected by noise emitted by a display device capable of refreshing displaying at every certain cycle is provided. The position detecting device includes a noise sensor disposed around a display device or a drive circuit of the display device, a noise detecting circuit that outputs noise detection information when noise input to this noise sensor is equal to or higher than a predetermined level, a pulse generating circuit that generates a pulse at the same cycle as the known cycle of a horizontal synchronizing pulse of the display device, phase control means that controls the phase of the output pulse of the pulse generating circuit in such a manner that the frequency at which the noise detection information is output in a predetermined time synchronizing with the output pulse of the pulse generating circuit becomes equal to or higher than a certain value, and a receiving circuit that receives a signal by a finger or a stylus in synchronization with the timing of the output pulse of the pulse generating circuit. |
