| 摘要 |
PURPOSE:To uniformize the surface luminance by forming alternately light diffusing parts, which are painted white, and light non-diffusing parts at a certain width ratio on the rear face of an area near a fluorescent lamp of a transparent plate along the optical axis of the fluorescent lamp to provide a stripe pattern. CONSTITUTION:With respect to a plane secondary light source where a fluorescent lamp 2 is brought closely into contact with one end face of an acrylic transparent plate 1, a white paint is coated on three end faces other than the end face on the fluorescent lamp side of the plate 1. An area having a length L1 (about 10mm) along the end face, which is brought closely into contact with the fluorescent lamp 2, of the transparent plate 1 is made transparent, and a stripe pattern 3 is formed in an area having a width L2 adjacent to this area. Light non-diffusing parts (0.25mm width) 4 and light diffusing parts (0.75mm width) 5 are repeated alternately along the optical axis of the fluorescent lamp 2 to form the stripe pattern 3. Parts other than light non-diffusing transparent parts 4 of the stripe pattern 3 are painted white as shown by dots. |
