摘要 |
PURPOSE:To make it possible to cause a light emitting surface of a large width to emit uniform intensity of light with a single light source by emitting parallel light beams of less attenuation with respect to distance with a fresnel lens in right-left directions in which a lighting device extends its width, and disposing in the light path of the parallel light beams a plurality of reflecting surfaces of a same shape for deflecting the light beams by reflection in the direction of irradiation. CONSTITUTION:Light beams from a light source 3 produce parallel light beams directed to the left with a left fresnel lens 4L, parallel light beams directed to the right with a right fresnel lens 4R, and parallel light beams directed to the front with a front fresnel lens 7. Because a left inner lens 5L with entire surface formed with left prism cuts 6L is disposed in the path of the light beams directed with the left fresnel lens 4L, all the parallel light beams are deflected at right angles with the left prism cuts 6L and enter a lens 2. Because the respective left prism cuts 6L are of a same shape, light beams entering the lens 2 are also parallel. As a result, the light beams incident on the lens 2 also have the same uniformity with that of the parallel light beams. |