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

Claim 20:
21. A phase difference plate comprising:
a substrate; and
a phase difference film formed on at least one surface of the substrate,
wherein the phase difference film is laminated in two or more layers, and
in a case where, in a plane parallel to a film formation surface of the substrate, on which the phase difference film is formed, an axis in which a phase of an incidence light is most delayed 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.