| 摘要 |
PROBLEM TO BE SOLVED: To obtain a liquid crystal display device capable of efficiently converging external light collected from all directions and a wide angle to the valid illumination range of the display device and efficiently illuminating a liquid crystal. screen. SOLUTION: An illuminating means for illuminating the display screen of the display device 20 is constituted of a lamp light source 21 arranged on the back of the device 20 as back light and external light such as solar light made incident from an external light incident window 28. First and 2nd lenses 22, 23 having wide lens action capable of converging external light made incident from all directions into the window 28 and illuminating the display screen are arranged between the window 28 and the rear face of the device 20. The lens face of the 2nd lens 23 which is formed on the opposite side of the device 20 is formed as a fine prism face 32 and a 3rd lens 24 for making much irradiation with lamp light to the visual field direction of the device 20 is arranged oppositely to the fine prism face 32 in the front of the light source 21. |
