An emissive element array of a plurality of organic EL elements is arranged linearly on a single-crystal silicon substrate or polycrystalline silicon substrate with a drive circuit including an element switching its respective emissive element. The organic EL emissive elements have an edge emitting structure utilizing light emitted in an edge direction perpendicular to the direction of deposition of electrode layers and organic compound layers, and is constructed such that the emitting area of one emisive element, S, as viewed in the direction of deposition, and the period of emissive elements disposed side by side, d, have the relationship of S>d.sup.2. In this way, organic EL techniques can be applied to provide the required amount of light exposure and to produce an exposure device that is small and inexpensive.