Abstract: For each of N imaginary regions divided at predetermined intervals in the direction of the rotation shaft of a developer roller (12), the amount of toner consumed when an image is formed is previously calculated. Then, the same amount of toner as a toner consumption amount calculated for each imaginary region is supplied to a development device (2) earlier by a time in which the toner supplied from a toner hopper (5) is transported to each imaginary region than at the time of the development. Thus, it is possible to maintain a toner concentration within the development device within a predetermined range without the toner being dispersed and an image formation speed being reduced even if an image having a high print rate is formed.

Abstract: For each of N imaginary regions divided at predetermined intervals in the direction of the rotation shaft of a developer roller (12), the amount of toner consumed when an image is formed is previously calculated. Then, the same amount of toner as a toner consumption amount calculated for each imaginary region is supplied to a development device (2) earlier by a time in which the toner supplied from a toner hopper (5) is transported to each imaginary region than at the time of the development. Thus, it is possible to maintain a toner concentration within the development device within a predetermined range without the toner being dispersed and an image formation speed being reduced even if an image having a high print rate is formed.

Abstract: An image forming apparatus has an image bearing member that moves at a specified speed; a toner pattern forming section for forming toner patterns of a specified type on the image bearing member under specified image forming conditions; a toner pattern detection member for detecting the toner patterns formed on the image bearing member; a toner amount varying section for varying a target amount of toner to adhere to the toner patterns; and a control section that calculates a toner adherence amount and a toner adherence position from detection results outputted from the toner pattern detection member and that performs image stabilization control to adjust the image forming conditions based on the calculation results. In the image stabilization control, the control section uses detection results of the same toner patterns both to calculate the toner adherence amount and to calculate the toner adherence position.

Abstract: A color image forming apparatus having photosensitive members; developing devices for developing electrostatic latent images formed on the photosensitive members into toner images with developers comprising toner and carriers; toner concentration sensors for detecting toner concentrations of the developers in the respective developing devices; a toner image bearing member for bearing the toner images temporarily; a toner adherence amount sensor for detecting toner adherence amounts of the toner images held on the image bearing member; and a controller for calculating, with respect to the developing devices, individual optimal developing bias voltage ranges within which a target toner adherence amount can be achieved while the toner concentrations of the developers are within a predetermined toner concentration range from a lower limit to an upper limit, so as to specify a common optimal developing bias voltage range that are commonly suitable for all the developing devices to achieve the target toner adherenc

Abstract: A color image forming apparatus having photosensitive members; developing devices for developing electrostatic latent images formed on the photosensitive members into toner images with developers comprising toner and carriers; toner concentration sensors for detecting toner concentrations of the developers in the respective developing devices; a toner image bearing member for bearing the toner images temporarily; a toner adherence amount sensor for detecting toner adherence amounts of the toner images held on the image bearing member; and a controller for calculating, with respect to the developing devices, individual optimal developing bias voltage ranges within which a target toner adherence amount can be achieved while the toner concentrations of the developers are within a predetermined toner concentration range from a lower limit to an upper limit, so as to specify a common optimal developing bias voltage range that are commonly suitable for all the developing devices to achieve the target toner adherenc

Abstract: An image forming apparatus has an image bearing member that moves at a specified speed; a toner pattern forming section for forming toner patterns of a specified type on the image bearing member under specified image forming conditions; a toner pattern detection member for detecting the toner patterns formed on the image bearing member; a toner amount varying section for varying a target amount of toner to adhere to the toner patterns; and a control section that calculates a toner adherence amount and a toner adherence position from detection results outputted from the toner pattern detection member and that performs image stabilization control to adjust the image forming conditions based on the calculation results. In the image stabilization control, the control section uses detection results of the same toner patterns both to calculate the toner adherence amount and to calculate the toner adherence position.