DISCHARGE LAMP IGNITION DEVICE

摘要

A discharge lamp ignition device that is safe, compact in size, and capable of carrying out fine control of lamp power is provided. The discharge lamp ignition device includes a primary circuit (10) connected to an alternating-current source (2), a transformer (6) to keep the primary circuit (10) insulating from a secondary circuit (20) applying a voltage to a lamp (4), and a photocoupler (5). A detector (22E) provided at the secondary circuit (20) detects an output electric current and an output voltage of the lamp (4), and a deviation of a lamp power from a predetermined power. A signal corresponding to the deviation detected by the detector (22E) is transmitted to the primary circuit (10) through the photocoupler (5) provided between the primary and secondary circuits (10) and (20). A switching controller (13) provided in the primary circuit (10) controls a switching operation for a constant power ignition in response to the signal transmitted from the photocoupler (5).