Abstract: An apparatus and method to update patch image formation frequency, in which an electrostatic latent image is formed on an image supporting object, and the electrostatic latent image is developed with a toner. The image formation apparatus includes a developing unit, a toner supply unit for supplying the toner to the developing unit, a patch image density detecting unit for detecting the density of a patch image formed on the image supporting object, a toner density detecting unit for detecting the density of the toner held in the developing unit, and a control unit that adjusts a generating interval of the patch image according to a detection result of the patch image density detecting unit.

Abstract: An image formation apparatus, and an image formation method are disclosed. An electrostatic latent image is formed on an image supporting object, and the electrostatic latent image is developed (made visible) with a toner. The image formation apparatus includes a developing unit, a toner supply unit for supplying the toner to the developing unit, a patch image density detecting unit for detecting the density of a patch image formed on the image supporting object, a toner density detecting unit for detecting the density of the toner held in the developing unit, and a control unit connected to the patch image density detecting unit and the toner density detecting unit on an input side of the control unit, and connected to the toner supply unit on an output side of the control unit, wherein the control unit adjusts a generating interval of the patch image according to a detection result of the patch image density detecting unit.