| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light guide plate or the like with a simple structure, small number of parts, easy to manufacture and cost reduced, and capable of radiating enough light within the angle range effective for display on a display surface of a liquid crystal display. <P>SOLUTION: The light guide plate is provided with a light guide plate main body having a light-emitting face, and a light diffracting means arranged on a face opposed to the light-emitting face of the light guide plate main body. The light of a light source is entered into the light guide plate main body from the end face thereof. The light diffracting means diffracts specific deflecting components of light of one or a plurality of specific wavelengths out of light incident upon the light diffracting means from the light guide plate main body with an angle a° satisfying formula (1): 0<a≤b+5 (here, cos(b)=n<SB>2</SB>/n<SB>1</SB>, provided, n<SB>1</SB>is a refractive index of the light guide plate main body, and n<SB>2</SB>is a refractive index of a medium in contact with the outside of the light-emitting face of the light guide plate main body) at a refraction angle of (90-a)°. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
