| 摘要 |
PROBLEM TO BE SOLVED: To convert a point light source into a surface light source of a good homogeneity. SOLUTION: The point light source is converted into a linear light source with a linear light guide board and further into a surface light source with a face-type light guide board. Otherwise, light from the point light source is reflected with a lamp reflector and made to be incident from at least two side faces of the face-type light guide board. Otherwise, the face-type light guide board whose upper face is rectangular is cut by a line of 45 deg. against one side of this rectangle from the upper face, In the face-type light guide board of a pentagon shape from the upper face after the removal, the point light source is arranged on this side of the side face which has an angle of 45 deg. to the other sides. |
