To elongate the service lifetime of a printing element.

The electrophotography printing engine 20 uses a light receiving device 22 having the image receiving face, a print-head 26 to form a latent image 46 on the light receiving device 22 by applying the light to it, and a developing device 40 to convert the latent image 46 to a printable image to be transferred from the light receiving device 22 to a printing medium during relative movement between the light receiving device 22 and the printing medium. The print-head 26 has a light emitting diode group arranged in a plurality of arrays in parallel with each other on a substrate. The substrate also supports a driver circuit which is connected to image forming electronics and drives each diode. An optical element executes focusing of the light of the diode on one line of the latent image. The focusing is simultaneously executed regarding each diode arranged in a plurality of the arrays.