Patent ID: 11899315
Assignee: FUJIFILM CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 7:
8. The phase difference plate according to claim 7,
wherein, in a case where a YS-axis, which is obtained by projecting the Y-axis corresponding to a maximum principal refractive index ny in the three principal refractive indices onto a plane parallel to the film formation surface and in which a phase of the incidence light is most delayed corresponding to the principal refractive index ny, is defined as a slow axis, a direction of the slow axis in a case where the substrate is rotated about the normal line is defined as an azimuthal angle of the substrate, and an azimuthal angle at which a phase difference generated with respect to the incidence light at an incidence angle of +15° with respect to the normal line is maximum is defined as a reference azimuthal angle, in azimuthal angles from 0° to 360°, an absolute value of a difference between a first phase difference of the incidence light in a case where an azimuthal angle is +45° with respect to the reference azimuthal angle and a second phase difference of the incidence light in a case where an azimuthal angle is −45° with respect to the reference azimuthal angle is 6 nm or less.