| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a backlight device without drastic changes in inclination of a reflective face, and capable of restraining leakage of light. <P>SOLUTION: The backlight device 101 includes a light guide plate 2 with a light-incident face 21 having an incident area 20 and an irradiation area 22 opposed to the same, and a light-emitting diode element column with a plurality of light-emitting diode elements 1 arranged. The light guide plate 2 is extended in a direction toward at least a first side 90 as seen from the incident area 20. The light guide plate 2 has a curved surface part 23 so as to be adjacent to a second side 91. The curved surface part 23 is for receiving light incident from the light-emitting diode elements 1 into the inside of the light guide plate 2 and reflecting it toward the first side 90. A cross-section shape of the curved surface part 23 can be expressed in: r=exp(-θ/tanα+C) in a polar coordinate display by r, θ as one point of the incident area 20 as an original point, provided, C is a constant, n<SB>O</SB>is a refraction index of the light guide plate 2, and α is a constant angle satisfying: 0<α≤π/2-sin<SP>-1</SP>(1/n<SB>O</SB>). <P>COPYRIGHT: (C)2008,JPO&INPIT |
