Abstract: A copying apparatus has a photoreceptor drum, a charger for charging the photoreceptor drum, an exposure lamp for exposing images to said photoreceptor drum, an apparatus for setting magnification rate of the images, a selector for selecting a first mode in which the images are exposed to the photoreceptor drum in the set magnification rate or a second mode in which the images are exposed to said photoreceptor drum in a magnification rate smaller than the set magnification rate, an apparatus for partially removing the charges of an unexposed portion adjacent to the latent electrostatic images formed on the photoreceptor drum when the second mode is selected, and a developer for developing the latent electrostatic images and the unexposed portion. When the second mode is selected, an index is formed by the removal of the charges at the unexposed portion adjacent to the latent electrostatic images formed on the photoreceptor drum.

Abstract: A copying apparatus is provided with a grid forming function wherein a grid pattern can be formed on plain copy paper to accurately and readily indicate the size or position of an image formed thereon. The copying apparatus includes a photosensitive member, a writing head including a plurality of linear writing elements, a driving circuit for driving the writing elements, a control system for controlling the driving circuit to cause the driving circuit, and thereby the writing head, to form an electrostatic image of a grid pattern on the photosensitive member, a developer for developing the electrostatic image to form a toner image of the grid pattern, and a transfer device for forming the grid pattern toner image onto a copy paper.