The Coriolis mass flow meter of this invention comprises two parallel curved flow tubes 1 and 2, a drive unit 15, and a pair of vibration sensors 16 and 17. A utilization computation part 7 computes utilization of each queue by computing the packet storage number of the each queue. This image display device can increase accuracy of white balance adjustment and reduce time required for the white balance adjustment. The posting unit posts a predetermined control time immediately after user terminal booting and a predetermined control time immediately after user login. The disinfecting unit is located in the heating housing.