OPTICAL ELEMENT AND METHOD OF MANUFACTURING THE SAME

To provide a technique reducing variance in retardation of a retardation layer.SOLUTION: An optical element includes a lens having a curved surface and a retardation layer formed on the curved surface of the lens. The retardation layer includes a liquid crystal layer having a slow axis and a fast axis. When viewed from a normal direction at the center of gravity of the curved surface, a division line which divides respective segments connecting the center of gravity and respective points at a peripheral edge of the curved surface in the proportion of 4:1 from the center of gravity to the peripheral edge of the curved surface, a first virtual line parallel with the slow axis passing the center of gravity, and a second virtual line parallel with the fast axis passing the center of gravity are set. When viewed from the normal direction, the first virtual line and the division line cross each other at a first point and a second point, and the second virtual line and the division line cross each other at a third point and a fourth point. The sum of thicknesses of the liquid crystal layer at the third point and the fourth point on the second virtual line is smaller than the sum of thicknesses of the liquid crystal layer at the first point and the second point on the first virtual line.SELECTED DRAWING: Figure 6 【課題】位相差層のリタデーションのバラツキを低減する、技術を提供する。【解決手段】光学素子は、曲面を有するレンズと、前記レンズの前記曲面に形成される位相差層と、を含む。前記位相差層は、遅相軸と進相軸とを有する液晶層を含む。前記曲面の重心における法線方向から見て、前記重心と前記曲面の周縁の各点とを結ぶ各線分を前記重心から前記曲面の周縁に４：１で分割する分割線と、前記重心を通る前記遅相軸に平行な第１仮想線と、前記重心を通る前記進相軸に平行な第２仮想線と、が設定される。前記法線方向から見て、前記第１仮想線と前記分割線とは第１点と第２点とで交差し、前記第２仮想線と前記分割線とは第３点と第４点とで交差する。前記第２仮想線上の前記第３点及び前記第４点での前記液晶層の厚みの和が、前記第１仮想線上の前記第１点及び前記第２点での前記液晶層の厚みの和よりも小さい。【選択図】図６