A light guide member illuminates with uniform light intensity distribution using the point light source light. On the lower end of the light guide member having a pair of side faces disposed oppositely, a groove is provided for receiving light output from each point light source and diffusing the above received light to at least three directions from the incident side toward the output side. Light components having directions using side-face reflection are generated in the light guide member, enabling light output to multiple directions from the cylindrical-shaped light guide member, and uniform illumination over a wide range. By using the ring-shaped light guide member, cost reduction is effectively achieved, and miniaturization of the illumination mechanism and the image capturing mechanism can also be attained.