| CPC G02B 5/0257 (2013.01) [G02B 5/3016 (2013.01)] | 13 Claims |
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1. An optical element comprising:
a plurality of optically anisotropic layers, each of which has an in-plane alignment pattern in which orientations of optical axes derived from a liquid crystal compound change continuously and rotationally along at least one in-plane direction, in a thickness direction,
wherein the optically anisotropic layers each have regions where lengths over which the orientations of the optical axes rotate by 180° in the at least one in-plane direction are different from each other,
wherein at least one of the plurality of optically anisotropic layers is an inclined optically anisotropic layer having a region where a plurality of pairs of bright lines and dark lines derived from the orientations of the optical axes in a cross-sectional image obtained by observing a cross section cut in the thickness direction along the at least one in-plane direction using a scanning electron microscope are present and the pairs of the bright lines and the dark lines are inclined at inclination angles which are different from each other with respect to a normal line of an interface of the optically anisotropic layer,
wherein the plurality of optically anisotropic layers are laminated so as to coincide with each other in regions where the lengths over which the orientations of the optical axes rotate by 180° in the at least one in-plane direction coincide with each other, and
wherein an optically anisotropic layer adjacent to the inclined optically anisotropic layer has a plurality of pairs of bright lines and dark lines derived from the orientations of the optical axis in the cross-sectional image, and bright lines and dark lines are connected to each other at the interface with the inclined optically anisotropic layer.
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