Abstract: An image forming apparatus includes an image bearing member, a latent image forming device that forms a latent image on the image bearing member, a developing device that develops latent image on said image bearing member to a toner image with a two-component developer, and a toner density detecting device that detects toner density of the two-component developer in which the toner image is formed and outputted as a visible image onto a transfer member. A control device is provided for agitating the developer for a predetermined time period during an initial setting is performed for the developer, detecting a toner density of said developer after the predetermined agitation, and performing an abnormal process when a result of the detection is out of the predetermined range.

Abstract: An image forming apparatus including an image bearing member, a latent image forming device which forms a latent image on the image bearing member, a developing device which develops the latent image using a two-component developer including a toner and a carrier and a toner supplying device which supplies toner into the developing device. A developer agitating device agitates developer in the developing device and a toner-density detecting device detects a toner density of developer in the developing device. A toner-density control device controls the toner density by operating the toner supplying device on the basis of a detected result according to the toner-density detecting device. A memory device stores resultant value of the toner density detected by the toner-density detecting device during image forming operations. The toner-density detecting device detects the toner density in a warm-up operation before starting the image forming operation by the image forming apparatus.