Abstract: A coordinate input apparatus includes a wireless vibrating input pen for alternately generating a first vibration having a first frequency and a second vibration having a second frequency different from the first frequency. A vibration transmitting member is provided for transmitting the first and second vibrations input from the vibrating input pen by contacting the vibrating input pen. A plurality of vibration detectors are coupled to the vibration transmitting member for detecting the first and second vibrations transmitted through the vibration transmitting member. Processing circuitry is included for deriving at least one coordinate of a position of the vibrating input pen on the transmitting member according to a transmission delay time between the first and second vibrations detected by the vibration detectors. Transmission and reception of timing information between the vibrating input pen and the main body of the apparatus is not required.