Abstract: A light source device applicable to a printer/copier includes a light source, an optical circuit board, a light source support, an outer cover, and a light source control panel, wherein the light source is fixed on the light source support; the light source support and the light source are mounted in the outer cover; the light source control panel is fixed on the outer cover; the light source is connected to the light source control panel; the optical circuit board is provided at a side opposite to the light source; and the optical circuit board is fixed on the outer cover. The light source device applicable to the printer/copier of the present invention has a simple structure, and realizes data output by controlling the point corresponding switches on the optical circuit board, and effectively improves the printing and copying speed and accuracy.