| 摘要 |
PURPOSE: A direct type back light unit for embodying a uniform screen by improving lamp mura is provided to build additional optical permeability structure at a light source and release the light diffusely to a wider area, thereby reducing luminance difference. CONSTITUTION: A plurality of linear light sources is parallely arranged in predetermined gap. An optical permeability structure surrounds the linear light source. In polygonal structure of the optical permeability structure, a closed angle &thgr;A and &thgr;E are in range of 2xSin-1(2xR1/P)<=&thgr;A=&thgr;E<=50° if interior angle of A is acute angle. And, the closed angle &thgr;B, &thgr;D, &thgr;F and &thgr;H are in range of 155°<=&thgr;B=&thgr;D=&thgr;F=&thgr;H<=270°-Sin-1(2xR1/P)-Sin-1(R1/G0). And, the closed angle &thgr;C and &thgr;G are range of 2xSin-1(R1/G0)<=&thgr;C=&thgr;G<=180°. |
