| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to execute inspection with excellent reliability while using a protective sheet entailing double refractiveness and substantially preventing the occurrence of errors of inspection results by specifying the crossing angle of the optical axes of the protective sheet and a phase difference plate. SOLUTION: This elliptical polarizing plate 4 is constituted by adhering and fixing a linear polarizing plate 1 and the phase difference plate 3 and adhering and protecting the outside surface of the this polarizing plate with the protective sheet 6. The intersection angle θ2 of the optical axes of the protective sheet 6 and the phase difference plate 3 is specified to >=15 deg.. If the intersection angle 6, of the optical axes of the protective sheet 6 and the phase difference plate 3 is small, the phase difference by the intrinsic phase difference plate 3 is eventually negated by a negation operation and the phase difference of the phase difference plate 3 is hardly reflected for the inspection. Further, the coloration by the phase difference plate 3 arranged between the linear polarizing plate 1 is dark when the optical axis of the phase difference plate 3 exists at 45 deg. with the absorption axis of the lineg polarizing plate 1 as shown by an arrow. The coloration is paler as the intersection angle θ1 is smaller and it is decorated at 0 deg.. The discovery of the unequal phase difference of the phase difference plate 3 is more difficult as the coloration is paler. |
