| 摘要 |
PROBLEM TO BE SOLVED: To utilize a luminaire under a quiet environment by arranging both optical axes of a lamp and a light guide inclined to the horizontal axis so that the lamp is positioned in the upper part than a beam incident end part of a light guide and by providing ventilation holes in the upper part and the lower part of a casing. SOLUTION: Optical axes 7 of a light guide and a lamp are so arranged as being inclined, preferably 40 deg. or more, to the horizontal axis 8 so that the lamp 2 with a reflection mirror is positioned in the upper part than a light guide beam incident end part 13. This constitution can reduce the effect of the heat generated by the lamp on the beam incident end part 13. Ventilation holes 10 are provided in the upper and lower parts of a casing 6 respectively so that the casing 6 inside can be cooled by the autoconvection by sucking the air heated by a lamp from the upper ventilation hole 10 and sucking exhaust or the open air by the lower ventilation hole 10, thereby reducing the effect of the heat from the lamp on the beam incident end part 13. This constitution can dispense with a cooling fan so as to generate no noise. |
