| 摘要 |
PURPOSE:To provide a projection illuminant device having the capability of maintaining much luminous energy of reflected light from the surface of a reflector among the quantity of light emitted from a lamp having an insulation film at both ends, and restraining a temperature rise at a sealing section positioned deep in the reflector. CONSTITUTION:Regarding insulation films 18a and 18b formed at both ends of a luminous tube 10, the height H1 of the film 18a formed at one end of the tube 10 where a reflector 2 is mounted, is kept less than the height H2 of the film 18b at the other end of the tube 10. As the height H1 of the film 18a at the sealing side of the tube 10 where the reflector 2 is mounted, is made less than the height H2, less light is shaded with the film H1 and a light quantity toward reflector surface becomes large. Also, the temperature of the sealing section liable to rise can be restrained, due to the position thereof deep in the reflector. |
