A container includes a container body, a body insert, a seal structure, and a cover. The plurality of lower electrodes is electrically connected to the plurality of common lines by a connecting conductive layer, and the lower electrodes and the pixel electrodes serve as the conductive layers of the capacitor. If the input voltage falls below the threshold value before the DC loop current has reached its maximum value, the DC loop current is reduced until the input voltage reaches at least the definable threshold value, and the error is signaled. In this case, the size of the figure is controlled to be changed in proportion to the distance between the eyepiecepart 10 and the target 12.