Abstract: An image forming apparatus includes an image bearing member, a toner image forming device, an intermediate transfer member, a primary transfer device, a toner adherence detector, a secondary transfer device, and a controller. The toner image forming device forms a toner image and a toner pattern for detection of degradation of toner on the image bearing member. The primary transfer device transfers the toner pattern onto the intermediate transfer member with transfer conditions that deliberately reduce transfer efficiency compared with that for image formation. The toner adherence detector detects an amount of toner adhered to the toner pattern at multiple places. The controller calculates a degree of degradation of toner based on the difference in the amount of toner adhered to the toner pattern detected by the toner adherence detector and adjusts secondary transfer conditions for the secondary transfer device based on the obtained degradation of toner.

Abstract: An image-forming apparatus, comprising: a rotatable photoreceptor; a charging device configured to charge a surface of the photoreceptor to be a target charge potential; an exposure device configured to expose a charged portion on the surface of the photoreceptor to form an electrostatic latent image; a developing device configured to develop the electrostatic latent image using toner to form a toner image; a transfer device configured to apply a transfer bias between the photoreceptor and a transfer member by applying an electrical potential of opposite polarity to the target charge potential to the transfer member facing the photoreceptor, and which transfers the toner image on the photoreceptor onto a body to be transferred by the transfer bias; a neutralization device configured to neutralize the surface of the photoreceptor by irradiating the surface with neutralization light after the transferring; and a pre-rotation device configured to perform a pre-rotation process.

Abstract: A toner pattern for detecting the degree of toner deterioration is created on a photosensitive element and transferred to an intermediate transfer belt by a primary transfer unit under a transfer condition different from that at the time of image formation. A toner adhesion amount detection unit detects the toner adhesion amount of the toner pattern at multiple places. A degree-of-toner-deterioration calculation unit calculates the degree of toner deterioration on the basis of the variation in data of the toner adhesion amount at multiple places detected by the toner adhesion amount detection unit. A background potential determination coefficient in a process control unit is controlled on the basis of the degree of toner deterioration calculated by the degree-of-toner-deterioration calculation unit.

Abstract: An image forming apparatus includes an image bearing member, a toner image forming device, an intermediate transfer member, a primary transfer device, a toner adherence detector, a secondary transfer device, and a controller. The toner image forming device forms a toner image and a toner pattern for detection of degradation of toner on the image bearing member. The primary transfer device transfers the toner pattern onto the intermediate transfer member with transfer conditions that deliberately reduce transfer efficiency compared with that for image formation. The toner adherence detector detects an amount of toner adhered to the toner pattern at multiple places. The controller calculates a degree of degradation of toner based on the difference in the amount of toner adhered to the toner pattern detected by the toner adherence detector and adjusts secondary transfer conditions for the secondary transfer device based on the obtained degradation of toner.

Abstract: An image forming apparatus includes a latent image carrier, a developing unit to develop a latent image on the image carrier with developer including toner and carrier, a developer bearing member, a first detector to detect a toner adhesion amount per unit area of a toner image developed by the developing unit, a second detector to detect humidity, and a controller to calculate an index indicating toner chargeability of the carrier based on detection results of the toner adhesion amount obtained by the first detector and perform a given control process based on calculation results thereof and including a data storage unit to store an algorithm to correct the index to a specific value according to a specific humidity, based on detection results of the humidity obtained by the second detector. The controller corrects the index obtained based on the amount of toner adhesion based on the algorithm.

Abstract: An image forming apparatus includes a latent image carrier, a developing unit to develop a latent image on the image carrier with developer including toner and carrier, a developer bearing member, a first detector to detect a toner adhesion amount per unit area of a toner image developed by the developing unit, a second detector to detect humidity, and a controller to calculate an index indicating toner chargeability of the carrier based on detection results of the toner adhesion amount obtained by the first detector and perform a given control process based on calculation results thereof and including a data storage unit to store an algorithm to correct the index to a specific value according to a specific humidity, based on detection results of the humidity obtained by the second detector. The controller corrects the index obtained based on the amount of toner adhesion based on the algorithm.