IMAGE FORMING DEVICE

PURPOSE:To prevent a change in image density, which results from the potential fluctuation of an image part by providing a means which sets the latent image potential of a reference image at the inbetween of the potential of a base part and that of the image part and a means which adjusts a developer supply amount based on a detecting signal from a reflected density detecting means. CONSTITUTION:The image forming device is provided with a latent image forming means 12 forming a latent image for a detecting reference image on a photosensitive body 1, the potential setting means which sets the latent image potential for the reference image at the inbetween of the potential of the base part and that of the image part, the reflected image detecting means 20 which optically detects the density of a visible picture obtained by developing the latent image formed by the latent image forming means 12, and the developer adjusting means which adjusts the developer supply amount based on the detecting signal from the reflected density detecting means 10. Since the potential of the reference image for a latent image is set at the inbetween of the potential of the base part and that of the image part when the reference image is formed, its potential is secured sufficiently even if the potential of the image part rises. Consequently, the fluctuation of toner concentration resulting from the potential fluctuation of the photosensitive drum can be prevented.