Patent ID: 9748087
Date: 2017-08-29
CPC Classifications: H01J

Claim:
1. A short arc type flash lamp of a double end type, comprising: a glass bulb including: an arc tube part having a substantially spherical shape; a first seal tube part extending outward along the tube axis direction to be continuous from one end of the arc tube part; and a second seal tube part extending outward along the tube axis direction to be continuous from the other end of the arc tube part, the first and second seal tube parts each having a straight tube shape and a smaller outer diameter than the arc tube part, a pair of main electrodes being arranged facing each other inside the arc tube part, and a pair of starting auxiliary electrodes being arranged inside the arc tube part; a gap being provided in an inner circumference of the second seal tube part; and a reduced diameter portion being formed on an outer peripheral surface of the second seal tube part corresponding to the gap in a circumferential direction, an electrode shaft of one of the main electrodes being sealed in the first seal tube part and led out air-tightly from the first seal tube part, and an electrode shaft of the other of the main electrodes and leads for the starting auxiliary electrodes respectively being sealed in the second seal tube part and led out from the second seal tube part, an external trigger being disposed in the reduced diameter portion by winding a wire in the circumferential direction on the outer peripheral surface of the second seal tube part, and the external trigger triggering preliminary discharge that occurs in the gap of the second seal tube part between the external trigger disposed in the reduced diameter portion of the second seal tube part and the electrode shaft of the other of the main electrode sealed in the second seal tube part, the preliminary discharge occurring prior to a main discharge occurring in the arc tube part.