Patent ID: 7759878
Filing Date: 2010-07-20
Classification: H05B

Abstract:
1. A lighting device for lighting a high-pressure discharge lamp having an outer tube, an interior of which is substantially under vacuum, the lighting device comprising: a ballast having at least a current limiting element; a high-voltage pulse generating circuit operable to generate a high-voltage pulse; a lighting discriminator operable to discriminate between lighting and non-lighting of the discharge lamp; a timer circuit operable to set a predetermined period of time; and a pulse-stop controller operable to stop generation of the high-voltage pulse; wherein when the lighting discriminator discriminates non-lighting after lighting has been discriminated, generation of the high-voltage pulse is stopped within the predetermined period of time set by the timer circuit, the discharge lamp further has an arc tube sealed in the outer tube and metallic elements disposed in the outer tube and outside the arc tube, and the predetermined period of time set by the timer circuit is a period of time within which the metallic elements are cooled below a temperature at which no discharge occurs between opposite polarities of the metallic elements.