Abstract:
An illumination structure includes an operation button having a front face on which is formed an identifying indication of ‘AUTO’ made by exposing an opalescent synthetic resin to easily penetrate light and the other parts are painted in black. It also includes an illuminating part provided on a back of the operation button, which illuminates a back of the identifying indication, and plural protrusions in a shape of ribs that regulate an intensity of light penetrating through the identifying indication. In this structure, the plural protrusions obstruct and diffuse the light beams that advance from the illuminating part toward the back of the identifying indication, thereby achieving uniform emission of the light beams from the whole identifying indication. Further in the manufacturing process of the operation button, contraction of a front face of the operation button accompanied with coagulation of the synthetic resin is dispersed by the plural protrusions.