Patent ID: 7745998

Claim:
A lighting unit comprising: a light guide board; a fluorescent discharge tube provided on a side surface of said light guide board, said fluorescent discharge tube including an electrode portion at an end portion of said fluorescent discharge tube; a lead wire including a contact connected to said electrode portion of said fluorescent discharge tube; and a holder forming a cavity around an entire circumference of said end portion of said fluorescent discharge tube, said cavity forming an air layer between said end portion of said fluorescent discharge tube and an inner wall of said holder, said cavity containing said end portion of said fluorescent discharge tube and said contact of said lead wire inside said cavity, wherein an inner diameter of said cavity of said holder is larger than an outer diameter of said fluorescent discharge tube, and said end portion of said fluorescent discharge tube is set inside said cavity so that said entire circumference of said end portion is loosely fitted within said cavity, to thereby form said air layer.