Patent attributes
A light guide plate includes a diffusing surface that diffuses incident light having a concave cylindrical surface shape with curvature in a first direction, and an exit surface having a convex cylindrical surface shape with curvature in the first direction. The light guide plate is constituted such that a pattern provided behind the diffusing surface is visible from the exit surface side. The light guide plate has an incident surface on at least one end of the light guide plate in the first direction, and prisms that are formed in the diffusing surface and reflect visible light from a light source that enters the light guide plate from the incident surface toward the exit surface. Each prism has a reflecting surface oriented toward the incident surface side, and an angle between the reflecting surface and the diffusing surface increases, the further the prism is from the incident surface.
