| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid crystal display device equipped with a back light capable of emitting linearly polarized light whose polarization degree is high, without using a polarizing plate. SOLUTION: The device is provided with a light condensing sheet 6 for enhancing the directivity of a luminous flux emitted from a cold cathode fluorescent lamp and guiding the luminous flux to a light transmission plate 3, and the sheet 6 is installed on the light incident plane of the light transmission plate 3, and the device is also provided with a collimator lens sheet 10 for controlling the angle of the advancing direction of the luminous flux which is emitted toward a reflection sheet 12 after returning from the reflection polarizing plate 8 to the light transmission plate 3 so that the luminous flux may advance in a direction near the normal direction of a 1/4 wavelength plate 11. Thus, the light using efficiency is enhanced and a bright display is obtained. |
