Optical device

An optical device comprising:

• a light guide made of a light-transmitting material and having
• an incident portion into which an external scene light is incident,
• an exit portion forming an outer surface located on one side in a first direction, and
• a terminal portion forming an outer surface located on one side in a second direction perpendicular to the first direction, opposite to the incident portion in the second direction;
• a holding member that partially covers the light guide and holds the light guide;
• and
• a louver disposed on the one side of the exit portion in the first direction and having at least one blade held by the holding member to suppress an incidence of external light into the exit portion, wherein
• the exit portion has a plurality of prisms formed in a protruding shape aligned in the second direction to transmit a part of an incident light incident from the incident portion into the light guide to outside of the light guide,
• the light guide and the holding member constitute a light guide unit,
• the light guide unit has
• a corner located on the one side of the light guide unit in the first direction and on the one side of the light guide unit in the second direction, and
• a corner extended outer surface extended from the corner to the other side in the second direction and formed as an outer surface facing the one side in the first direction at the other side in the second direction,
• the corner extended outer surface includes a curved surface having a radius of curvature of a predetermined standard or more at the corner and extended from the other side to the one side in the first direction while bending toward the other side in the second direction,
• the corner extended outer surface is formed as a part of the terminal portion or as a part of a terminal cover portion of the holding member that covers the terminal portion,
• the louver is arranged such that an imaginary spherical shape of the predetermined standard is spaced apart from the prisms in a state where the imaginary spherical shape is closest to the prisms while being in contact with the louver and the corner extended outer surface without intersecting the blade, and
• the radius of curvature of the curved surface of the corner extended outer surface and the imaginary spherical shape are determined based on the predetermined standard.