Optical component, touchscreen panel, and display device

The invention provides an optical component, a touchscreen panel, and a display device. The optical component is disclosed for improving display visibility of a display part of a display device in circumstances in which the optical component includes a resin part that is uncontrolled with respect to phase difference. The optical component 200 can be disposed on an emitting direction side of a display part 100 capable of emitting linearly polarized light. This optical component 200 includes a resin part 210, which has translucency and is uncontrolled in terms of phase difference, and a phase plate 220, which can be disposed between the display part 100 and the resin part 210. The phase plate 220 has three to five times as large a retardation as the resin part 210.