A prism block is provided at least one notch to propagate in the light flux in air, on an optical path from entrance of a light flux via a first portion of the prism block to exit of the light flux via a second portion of the prism block. The notch is configured such that the light flux exiting from inside of the prism block via a first interface of the notch between the prism block and the air re-enters the prism block via a second interface between the air and the prism block, the second interface facing the first interface.

A light-guide member includes a light-incident surface formed at an end portion of the light-guide member in a first direction, a light-emitting surface that is elongated in the first direction and that includes first and second light-emitting regions, which cause light to be emitted in different directions in a first cross section that is perpendicular to the first direction, a common deflecting portion that deflects light from the light-incident surface and causes the light to be emitted from the first and second light-emitting regions to the outside, and first and second protruding portions each of which is located on one of two sides of the deflecting portion in the first cross section, the first and second protruding portions protruding in a direction away from the light-emitting surface with respect to the deflecting portion.