| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a planar lighting device capable of improving visibility of designated display symbols without increasing power consumption of a light source of the planar lighting device. <P>SOLUTION: In the planar lighting device, dome-shaped dots 24 forming a light scattering pattern 22 and having elliptical shapes in a plan view are arranged so as to make an elongated direction of the elliptical shape be parallel or approximately parallel to a right and left direction when a user looks at the display symbols 3a by straightly facing the display symbols 3a. Further, the light source is arranged on a side face of a light guide plate opposite to the user. Thus, light from the light source is scattered with the dome-shaped dots 24 having the elliptical formation in the plan view. Here, an amount of light advancing in a direction orthogonal to a glance direction of the user becomes little, an amount of light advancing in the eye direction of the user becomes large, and the light has a light distribution having a peak in an angle area coincided with the eye direction of the user. Therefore, visibility of the designated display symbols 3a can be improved without increasing power consumption of the light source of the planar lighting device 4. <P>COPYRIGHT: (C)2013,JPO&INPIT |
