DIGITAL IMAGE FORMING DEVICE

PROBLEM TO BE SOLVED: To provide a digital image forming device with which real-time copy is enabled even in the case of a long original while suppressing original conveying speed even at the time of magnification change of a large reduction rate. SOLUTION: This device is provided with an original protecting mode processing means for thinning every other line of original image information in a sub scanning direction through a thinning means by reducing the speed of original conveyance by means of an original conveying means to 1/2 of a prescribed conveying speed when an original protecting mode is designated by a designation means 75. Thus, when the original protecting mode is designated by the designation means 75 even in the case of performing a variable magnification copy with a large reduction rate to a long original, since the original conveying speed is reduced to half of a prescribed conveying speed required for that magnification, and every other line of the original image information in thinned the sub scanning direction, a copied image of designated magnification rate can be obtained in real time without damaging the original.