LIGHT SOURCE DEVICE AND LIGHT EMITTING TUBE

摘要

It is an object to make cooling efficiency for a light emitting tube as much improved as possible with the avoidance of increase in device cost. A light source device is provided with a light emitting tube (1) including outer connection electrodes (EO) at both edge portions in its longitudinal direction, and a cooling member (CM) formed to be substantially cylindrical for cooling the light emitting tube (1) arranged in its inner space in a non-contact condition, wherein the light emitting tube (1) is set in its existing position in the inner space so that an interval between the upper end of the light emitting tube (1) and the inner wall of the cooling member (CM) is shorter than that between the lower end of the light emitting tube (1) and the inner wall of the cooling member (CM).