A first lens and a second lens are bonded, and each of a light emitting plane and a light incident plane is a flat surface to shorten a configuration in an optical axis direction, and simultaneously, various optical elements such as a transmission/reflection selection member and the like can be mounted on a flat surface portion. Further, by providing a half mirror in a bonding portion between a convex surface and a concave surface to give power in folding an optical path, an image with a wide angle of view can be formed.