A first amplifier circuit (132) included in a voltage generating circuit
(114) includes a differential circuit formed of P-type TFT elements
(P101, P102) and N-type TFT elements (N101, N102), a constant current
circuit (150a, 150b) and an N-type TFT element (N103). Constant current
circuit (150a; 150b) includes a P-type TFT element (P132a; P132b), a
capacitor (C132a; C132b), switches (S104a-S106a; S104b-S106b) and a
resistance element (R132a; R132b). Capacitor (C132a; C132b) holds a
voltage on a node (204; 208) in a voltage setting operation, and thus
when a current is being supplied to the diode-connected P-type TFT
element (P132a; P132b).