| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the number of LEDs without causing nonuniform brightness in a liquid crystal display incorporating a direct backlight using an LED as the light source. <P>SOLUTION: LED 30 is arranged on the side of an end A1 rather than the lower face of a cylindrical lens 20. Light emitted from an LED 30 is output, as diffused light, upward from an end diffusion surface 24. An area between points M and N in Fig.4 is a total-reflection surface 21, which reflects the light from the LED 30 to transmit the light to the side of another end portion A2 of the lens. Through an upper diffusion surface 23 formed on the top surface of the lens 20 and a lower diffusion surface 22 formed on the bottom surface of the lens, the diffused light is emitted upward from the lens, to thereby emit uniform light from all over the top surface of the lens. <P>COPYRIGHT: (C)2011,JPO&INPIT |
