Abstract: A guide plate 30 has a back face 34 provided with a great number of micro-reflectors 90 which has a guide portion and a conversion output portion including a valley. The conversion output portion reflects twice input light P at inner slopes, generating inner output light Q directed obliquely as to be distant from an incidence end face 32. Inner output light Q is inner-incident to a slope of projection row PR on an emission face 33, with the result that some of the inner-incident light becomes a direct escaping light and much of the other reaches the emission face 33 again after travelling along various paths. At the second time or later chances of escaping, an actual escaping occurs to generate an indirect escaping light. A mixed emission suitably blended of the direct and indirect light is directed to directions, which are modified to directions around a roughly frontal direction by prism sheet PS before being supplied to a LCD panel or the like to be illuminated.

Abstract: A light guide plate (20) includes a light input end (21), a light output face (23) adjacent the light input end, and a back face (22) opposite to the light output face. A plurality of fine dots (26) are formed on the back face arranged in a uniform, rectangular array. The dots in a same column have a same size. The dots in a same row increase in size. A radius r of the dots in each row thereof varies as a function of a column number X of a given dot, in accordance with the formula: r=A+BX+CX2+DX3+EX4+FX5, wherein: the column number X varies in consecutive whole numbers from a value of one for the column nearest the light input end to a maximum value for the column most distal from the light input end; and A, B, C, D, E, and F are constants.

Abstract: A light guiding plate guides light from a light source and irradiates the light onto a display portion. The light guiding plate has an exit plate facing the display portion, and a reflection-exit plane opposite to the exit plane. The reflection-exit plane has a first end intersecting an incidence plane and a second end intersecting an opposite end plane. An inclination angle, defined by the exit plane and a line that contains the first end and the second end, is greater than 0.20° and less than 0.75°. The reflection-exit plane includes a light admission portion that reflects light entering through or reflected on the incidence plane to the exit plane.

Abstract: A backlight unit includes a light emission part having a lamp for emitting light beams and a lamp housing for mounting the lamp therein and for reflecting the light beams from the lamp; a light guide panel for guiding the light beams from the light emission part; a reflecting plate under the light guide panel for reflecting the light beams that progress to a lower surface and a side surface of the light guide panel; a diffusion sheet having a thickness of about 113 ?m for diffusing the light beams that have passed through the light guide panel; and a prism sheet having a thickness of about 165 ?m and having a half-power angle of at least about 40° for controlling progress directions of the light beams that have passed through the diffusion sheet.