Patent ID: 7486885

Claim:
An illumination apparatus installable in a photographing apparatus including a photographing lens barrel and a light source located in a circumference of the photographing lens barrel, the illumination apparatus comprising: a first optical member to which light emitted by the light source is made incident and which serves to guide the incident light in a predetermined direction; and a second optical member having an emission surface, from which light is emitted toward an optical axis direction of the photographing lens barrel, and connected to the first optical member, wherein the second optical member further has a light direction conversion surface disposed to face the emission surface for, while regulating a traveling direction of light made incident on the incidence surface within the second optical member, guiding the light to the emission surface, and a plurality of prism-like portions each having a total reflection surface and a reincidence surface are continuously formed in the light direction conversion surface; and wherein of light which travels within the second optical member to reach the total reflection surface of one of the prism-like portions, only light of a predetermined angle component is totally reflected on the total reflection surface toward the emission surface, and light which is not totally reflected on the total reflection surface other than the light of the predetermined angle component is refracted in the one prism-like portion to be guided to an outside of the second optical member once and is then guided to the second optical member again through the reincidence surface of a prism-like portion next to the one prism-like portion, wherein the second optical member comprises first, second, and third areas, the first area bordering the first optical member, and the second area being between the first and third areas, wherein the first area is configured so that an envelope connecting vertices of the prism-like portions is inclined from a boundary between the first area and the first optical member to the second area in such a direction that the thickness thereof increases in the direction from the connection portion to the second area, wherein the second area has a fixed thickness, and wherein the third area is configured so that an envelope connecting vertices of the prism- like portions is inclined from the second area in such a direction that the thickness thereof decreases from the boundary between the second and third areas.