A first pattern and a second pattern are stacked with each other. In a pattern of a first circuit for high voltage, a GND is formed as a solid pattern. In a pattern of a second circuit for low voltage, a GND is formed as a solid pattern. The solid pattern of the GND of the pattern of the first circuit for high voltage and the solid pattern of the GND of the pattern of the second circuit for low voltage partially face each other, thereby improving noise-resistant performance of the circuit for high voltage.