| 摘要 |
PURPOSE:To obtain a light source suitable for a visual inspection for printed boards, photomasks, and the like, when a body to be lighted is simultaneously lighted by using a plurality of discharge lamps, by relatively reducing the varying ratio of the luminance of individual lighting lamp with respect to the synthesized luminance of the discharge lamps. CONSTITUTION:An optical system is constituted by a plurality of optical elements 10-1-10-5. In the individual elements, changing means to parallel luminous fluxes, which comprise mercury lamps 1-1-1-5, collimator lenses 3-1- 3-5, and back mirrors 2-1-2-5, are provided. The luminous fluxes directed toward the lenses 3 from the mercury lamps 1 and the luminous fluxes in the opposite direction are reflected and overlapped by using the lenses 2. With respect to the parallel luminous flux of one element 10-1 of these elements, the parallel luminous fluxes of the other elements 10-2-10-5 are made to be right angles. Half mirrors 5A- 5D, which are slanted at 45 degrees, are arranged at the intersections of the parallel luminous fluxes, and the parallel luminous fluxes are aligned in the same direction. Thereafter, said synthesized parallel luminous fluxes the converged by a condenser lens 6 and projected on a body to be lighted. |
