| 摘要 |
<P>PROBLEM TO BE SOLVED: To give a viewing angle restricting function comparable to an already available louver film to a viewing angle control sheet, and to prevent occurrence of moire. <P>SOLUTION: A liquid crystal display device 1 includes a liquid crystal panel 10 for display and the viewing angle control sheet 20. The viewing angle control sheet 20 includes a retardation plate 21 between an upper polarizing plate 22 of the control sheet and a lower polarizing plate 23 of the control sheet. The retardation plate 21 is formed by laminating a plurality of kinds of retardation plates with mutually different refractive indexes. In the viewing angle control sheet 20, either one of a retardation value Re of a white display region of the display device and a retardation value Re of a black display region satisfies nλ/2-λ/4<Re<nλ/2+λ/4 and the other one satisfies nλ-λ/4<Re<nλ+λ/4 (wherein n is an integer of ≥1) by combining the polarizing plates 22, 23 and the retardation plate 21. <P>COPYRIGHT: (C)2008,JPO&INPIT |
