EL ARRAY HEAD

PURPOSE:To obtain a good output of a printer by providing a photo-waveguide from the lower end of an EL light emitting element up to the vicinity of the end surface of a substrate, and forming said photo-waveguide into the shape to which the projected light is converged. CONSTITUTION:Two adjacent photo-waveguides, for example, Fi-j and F(i+1)-j are arranged so that the light projecting ends thereof are almost in contact with each other. In other words, a light 53 projected by a light emitting part 50 of an EL element is reflected sometimes by the side face of a photo-waveguide 51. The reflecting angles 54, 55 at this time become smaller towards the projecting end of the photo-waveguide 51 and the projected lights 7 become parallel. As a result, the profile of the projected light of an EL array head at the surface of a photosensitive body becomes good. Since the adjacent photo-waveguides are in contact with each other at the projecting ends thereof, the adjacent dots are brought in touch with each other at the developing time, without generating an unnecessary space between dots, thus realizing high- quality printing.