| 摘要 |
PURPOSE: To reduce the power consumption, to raise the luminance, and to reduce the dead space by arranging a single-tube fluorescent lamp around a light guide means and leading out the lamp electrode of one end and that of the other in the same direction. CONSTITUTION: A U-Shaped Single-tube lamp is used as a fluorescent lamp 1 and is arranged around three sides of a plane quadrangular light guide body 2. Lamp electrodes 1a and 1b in one end and the other of this fluorescent lamp 1 are led out in the same direction. Consequently, the quantity of light of the luminous flux made incident on the light guide body 2 is increased by the increase of length of the lamp in comparison with a straight double-tube lamp or an L-shaped tube lamp in the edge light system, and the luminance of light emission is raised. Since lamp electrodes 1a and 1b are led out in the same direction, the dead space is reduced. Preferably, first and third sides of the U-shaped fluorescent lamp 1 arranged around three sides of the light guide body 2 are made free, and the lamp 1 is fixed by the second side. Thus, a trouble like a break of the fluorescent lamp 1 is prevented even if this device is used in a place of much oscillation like a vehicle. |
