Signal light unit having heat dissipating function
 A heat sink, made of a highly heat-conductive material is placed on the back of a circuit board upon the front of which many LEDs are arrayed as the signal light source. The heat sink, generally formed as an aggregate of a number of fins, need not necessarily be fitted in one piece with the back face of the board but may be indirectly connected to the back face of the board with a heat absorber being placed between the heat sink and the back face of the board. 
Y H F G H B F B F F F F F
Y10S H05K F21V G08G H05K B61L F21W B61L F21V F21V F21V F21Y F21V
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Morikawa Uchiyama Tsuzawa Waki Kato Tominaga
Tadahiro Yoshinori Masami Osamu Hiroshi Muneharu