A plurality of insulation supports are provided around a zinc oxide component, and the zinc oxide component and a plurality of insulation supports are integrally molded into an insulation casing. The image is stored and accessing of the image by a user is detected. The quadrature demodulation compensation section is configured to perform a compensation process of compensating for a characteristic difference between the frequency characteristic of a first filter that performs filtering of the I signal and the frequency characteristic of a second filter that performs filtering of the Q signal.