JPS6472451A - Single base type fluorescent lamp - Google Patents

Abstract

PURPOSE:To improve the extent of heat radiation out of a base by bending the end of a fine tube so as to be almost paralleled with a bottom surface of the base, and attaching the end of this fine tube tight to the base bottom via a bonding agent mixed with powder or small pieces of metal or a metal oxide. CONSTITUTION:In a bend type light emitting tube 1, a bridge connection 2 is provided in almost U-shaped form, and a glass stem 4 with an exhaust fine tube 3 is sealed to a leg end at the side opposed to this connection 2 as holding an electrode 5. Either end of this fine tube 3 is being bent and attached tight to the bottom of a base 6 being attached to the leg so as to contain this bent edge with a bonding agent mixed with metal powder, while a rare earth phosphor 8 is applied on an inner surface of the light emitting tube 1, and about 3.5 Torr of Ar and Hg are sealed in the inner part. Since heat conductivity is high enough owing to the metal powder mixed in the bonding agent 7, heat in the fine tube is efficiently transmitted to the base 6 and thereby heat radiation takes place so that even if the fine tube is shortened in length, temperature at the tip part can be regulated to such a temperature that Hg vapor pressure becomes an optimum level from a luminous surface and, what is more, the base 6 can be sharply made compact in size.