Patent ID: 7804259

Claim:
A discharge lamp ballast apparatus comprising: a power supply section for supplying AC power to a discharge lamp from a DC power supply; a lighting control section connected to said power supply section for controlling operation of said power supply section; a fault detecting section for detecting a fault of the discharge lamp; a first storing section for storing fault detected by said fault detecting section; a lighting delay detecting section for detecting lighting delay time from beginning of starting operation to lighting of the discharge lamp; a reigniting voltage measuring section for measuring a discharge lamp voltage immediately after switching of polarity applied to the discharge lamp according to AC lighting as a reigniting voltage; a no-current flowing duration measuring section for measuring a period of time during which a current does not flow by detecting a discharge lamp current immediately after switching the polarity applied to the discharge lamp according to the AC lighting; a going out counting section for counting a number of times of going out by detecting going out during lighting of the discharge lamp; and a second storing section for storing into a storage device respective outputs of said lighting delay detecting section, said reigniting voltage measuring section, said no-current flowing duration measuring section and said going out counting section as operation records.