BULB TYPE FLUORESCENT LAMP

摘要

A bulb type fluorescent lamp in which the temperature at a coolest point can be lowered regardless of vertical orientation of a light emitting tube and stabilized output is attained at the time of normal lighting. The bulb type fluorescent lamp (1) encapsulating mercury comprises a light emitting tube (2), a ballast (3) for lighting the light emitting tube (2), a plate (8) having one side for holding the light emitting tube (2) and the other side being fixed with the ballast (3), a housing (4) having a base (5) and containing the ballast (3), and an outer tube globe (6) covering the light emitting tube (2). The bulb type fluorescent lamp (1), characterized in that provided are a protrusion (2a) formed at the distal end (7a) on the side opposite to the base (5) of the light emitting tube (2) and becoming the coolest point when the light emitting tube (2) is lighted while directing the base (5) upward, and an exhaust pipe (7) extending from the light emitting tube (2) into the housing (4) while penetrating the plate (8) in order to exhaust the interior of the light emitting tube (2) and having the tip end (7a) becoming the coolest point when the light emitting tube (2) is lighted while directing the base (5) downward.