LIGHT GUIDE PLATE USED IN PARALLEL AND BACK LIGHT USING THE SAME

PROBLEM TO BE SOLVED: To improve a liquid crystal back light for a large-size liquid crystal display screen of a wall television set. SOLUTION: A great number of strip-like light guide plates B each having protruding edges 11 on the both sides in the width direction are arranged parallel to one another, and a linear light source 4 is disposed in each fitting groove 14 formed by butting the adjacent protruding edges 11 to be in contact with each other to constitute a liquid crystal back light (A). The back face of the light guide plate B is provided with a light guide pattern 15 having the peak at the center position in the width direction to guide the light from the linear light source 4. The surface of the protruding edge 11 has a transmission suppressing pattern 16 formed by printing with a mirror ink in the plane direction so as to suppress transmission of the light from the light source 4 and to suppress increase in the luminance in this region. Thus a large-size back illumination with high uniformity and high luminance using many linear light sources 4 can be obtained.