An enlarging unit comprises a concave Fresnel lens warped convexly toward an image forming unit side, the image forming unit is held between a light transmissible support plate warped convexly toward the image forming unit side and the enlarging unit warped convexly toward the image forming unit side, and peripheries of the support plate and the enlarging unit are fixed or semi-fixed. Thereby, deformation caused when the incident side and emission side micro-lens arrays are molded and deformation due to environmental temperature and humidity change are corrected, and both components are always maintained in close contact.