Patent ID: 7492104
Filing Date: 2009-02-17
Classification: H01J,H05B,Y02B

Abstract:
1. A high pressure discharge lamp comprising: an outer tubular bulb whose inner space is exhausted to a vacuum; an arc tube contained in said outer tubular bulb; and a voltage reducing switching element for reducing a voltage applied to said arc tube, said voltage reducing switching element comprising a heat sensitive switching element and a starting-voltage reducing element which are connected in series, wherein during a period in which said heat sensitive switching element has a predetermined temperature or higher, said heat sensitive switching element is closed to electrically connect said arc tube and said voltage reducing switching element in parallel, so that said starting-voltage reducing element is operated, and during a period in which said heat sensitive switching element has a temperature lower than the predetermined temperature, said heat sensitive switching element is opened so that said starting-voltage reducing element is not operated.