The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. A memory circuit and a DA converter circuit in the signal line driver circuit are commonly used for n signal lines. The anode electrode of each of the unit pixels comprises a first film having a high reflectivity and a second film for adjusting a work function. A spacer is formed under the shaped spacer and a liner is formed under the spacer.