DISCHARGE LAMP LIGHTING DEVICE, LUMINAIRE AND ILLUMINATION SYSTEM

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of suppressing transmission/reception of conduction noise. SOLUTION: This discharge lamp lighting device is provided with: a photocoupler PC1; a pulse generation circuit 22 for turning one/off a light emitting element of the photocoupler PC1 at a duty ratio in response to a voltage value of a light control signal DC1 by inputting the light control signal DC1 being a D.C. signal of a voltage value corresponding to desired optical output; a control signal generation circuit 23 for generating a control signal being a D.C. signal of a voltage value linearly changing with respect to the voltage value of the light control signal DC1 in response to the duty ratio of the output of the photocoupler PC1; and an inverter circuit 1 for supplying, to a discharge lamp La, A.C. power so as to light the discharge lamp La at optical output linearly changing with respect to the voltage value of the control signal. By interlaying the photocoupler PC1 between the input side of the light control signal DC1 and the output side of the control signal, the transmission/reception of conductive noise can be suppressed. COPYRIGHT: (C)2007,JPO&INPIT