A printer head capable of increasing intensity of dot-like light irradiated onto a record medium without requiring to increase a drive voltage or the number of printer heads arranged. The optical printer head includes a luminous element including two luminous dot arrays arranged in parallel to each other at a predetermined interval in a sub-scanning direction. The luminous dot arrays each are constituted of a plurality of luminous dots which have a dimension in the sub-scanning direction increased by a predetermined magnification as compared with that in a main scanning direction and are spaced from each other at identical intervals in the main scanning direction. The luminous dots of the two luminous dot arrays are arranged in an offset manner while being deviated from each other in the main scanning direction by a distance equal to the dimension thereof in the main scanning direction. Also, a reduction optical system is arranged for carrying out irradiation of light emitted from the luminous dots while reducing a dimension of the light in the sub-scanning direction by a reciprocal of the predetermined magnification.