| 摘要 |
PURPOSE:To obtain a back light which is large in the exit light quantity from a light transmission body of a back light provided with a cold cathode fluorescent lamp within a lamp reflection cover by setting the length in the thickness direction of the light transmission body at the section of this cold cathode fluorescent lamp smaller than the length in the direction perpendicular to the thickness direction of the light transmission body. CONSTITUTION:The lamp reflection cover 2 is internally provided with the cold cathode fluorescent lamp 5 having an elliptical section. The length in the section of the cold cathode fluorescent lamp 5 in the thickness direction (a vertical direction at the plane of the Fig.) of the light transmission body 1 is smaller than the length in the direction (a lateral direction at the plane of the Fig.) perpendicular to the thickness direction of the light transmission body 1. Since the light emission area of the cold cathode fluorescent lamp 5 of this back light is large, the quantity of the light emitted from the cold cathode fluorescent lamp 5 is large as well. In addition, most of the light emitted from the side opposite to the end face of the light transmission body 1 of the cold cathode fluorescent lamp 5 is reflected by the lamp reflection cover 2 and, therefore, almost the whole of the light emitted from the cold cathode fluorescent lamp 5 is usable. Then, the quantity of the light emitted from the light transmission body 1 is large. |
