| 摘要 |
PURPOSE:To improve the utilizing efficiency of light, by condensing the light radiated from a light source onto the incident end face of an optical fiber bundle by means of a light condensing reflecting mirror. CONSTITUTION:Light from a light source 1 of a short-arc type mercury-arc lamp is condensed onto the 2nd focal pint of a light condensing reflecting mirror 2 through the mirror 2 and the whole quantity of the light is introduced to the incident end face 3a of an optical fiber bundle 3 positioned to the 2nd focal pint. The outgoing end 3b of the optical fiber bundle 3 has a flat-like shape and the radiated optical beam from this end 3b forms an optical beam radiated at a fixed angle on the same plane and becomes an arc-like slit of about 1-4mm in width after it is repeatedly reflected by a spherical mirror 4, plane mirrors 6 and 6 and other spherical mirrors 5 and 5 and by the work of the spherical mirrors 4 and 5, and the arc-like light passing through a photomask 7 forms an image on a wafer 11 which is an irradiated surface as a photomask pattern after it is repeatedly reflected by a trapezoidal mirror 8, concave mirror 9, and convex mirror 10. |
