DISCHARGE LAMP LIGHTING DEVICE

• Main Authors: KITADOU MASAHARU, ITO HISAHARU, KIDERA KAZUNORI
• Format: Patent
• Language: English
• Published: 10.03.1998
• Edition: 6
• Subjects: ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device by which deterioration of a discharge lamp can be judged in an early stage. SOLUTION: A control part 8 carries out an output control of an inverter part 2 corresponding to a standard value from a computing part 7. The detected outputs of the lamp current detecting part 4 and a lamp voltage detecting part 5 are converted into digital signals in an A/D converting part 6 and sent to the computing part 7. At the time of transient lighting from the starting to the stable lighting, the computing part 7 compares the absolute value of the difference of the lamp electric power detected value W1a and the standard value W0 of electric quantity with a prescribed value α and in the case the absolute value of the difference of both values is smaller than the prescribed value α, the computing part 7 determines that nothing is abnormal and judges whether the transient lighting mode is finished or not. To the contrary, the absolute value is higher than the prescribed value α, it is determined that deterioration of the discharge lamp 3 rather proceeds and an alarm is given to a user by informing abnormality by sound, light, etc., from an abnormality informing part 9 through the control part. Consequently, deterioration of the discharge lamp 3 can be detected at high precision and in an early stage as compared with a conventional one.