| 摘要 |
PROBLEM TO BE SOLVED: To restrain a temperature rise of a lighting circuit parts in a housing so as to decrease a trouble for attaining a long service life. SOLUTION: This luminaire comprises a wiring board block B where several kinds of lighting circuit parts A2 , A3 including a main semiconductor switching element A1 controlling a lamp current on one surface of a wiring board P; a housing 10 which houses the wiring board block B in such a way that the other surface of the wiring board P is turned to a ceiling part; and a lamp at a lower part of the housing 10. In the luminaire, a bottom part of the housing 10 is comprised of a double structure of an outer wall 10b2 and an inner wall 10b3 . |
