| 摘要 |
<p>[Problem] To provide a light diffusing sheet which enables the light from a lightguide plate or light source of the backlight unit to be conducted to lens film after having been converted to diffused light having a small brightness peak angle, and which generates neither a moiré or interference fringe nor luminance unevenness, and is advantageous also from the standpoints of productivity and cost, and to provide a backlight unit having this light diffusing sheet incorporated therein. [Means for Solution] The invention is composed of a light diffusing sheet 10 comprising a light-transmitting resin, characterized by having fine recesses formed in at least one of the surfaces 2 thereof, the fine recesses 3 having a shape which is any of the shape of an inverted polyangular pyramid, the shape of an inverted truncated polyangular pyramid, the shape of an inverted cone, and the shape of an inverted truncated cone. brightness peak angle of diffused light is reduced, which restrains both a moiré and interference fringe, according to light refraction due to inclined face of fine recess 3 or a taper face. The invention is composed of a backlight unit characterized by including the light diffusing sheet and has been disposed on upper side of lightguide plate 20, or in front of a light source, so that that surface of the sheet which has fine recesses formed therein serves as a light emission side.</p> |
