An image forming apparatus includes an image carrier that holds an image, which is formed by developing a latent image and which is transferred onto a recording medium, a developing device that is disposed adjacent to the image carrier and that develops the latent image, a light-reflection-type sensing unit that is disposed below the developing device in a vertical direction and that detects the image on the image carrier, and a guiding member that guides the recording medium, which is transported between the developing device and the sensing unit, and that covers an upper side of the sensing unit in the vertical direction in a state where a space is ensured on an optical path of the sensing unit.

An exposing unit forms a latent-image electric potential on each photosensitive drum. A detecting toner image of each color is transferred to an intermediate transfer belt using a first potential difference between a latent-image electric potential and the potential of an intermediate transfer belt at each primary transfer portion. When the polarity of voltage to be applied from a transfer power source to a secondary transfer roller is to be switched to an opposite polarity while the detecting toner image of each color is passing through each primary transfer portion, the absolute value of a second potential difference between the potential of the intermediate transfer belt and the background electrical potential of each photosensitive drum is made equal to or greater than the absolute value of the first potential difference by a control unit.

An image forming apparatus includes: an image bearing member to which a toner is supplied; a cleaning blade that removes the toner supplied onto the image bearing member; a hardware processor that performs control such that a tonner pattern for cleaning blade inspection is formed on the image bearing member; and a detector for detecting a toner that has slipped through the cleaning blade after the toner pattern has been allowed to reach the cleaning blade. The hardware processor performs control such that a contact portion of the cleaning blade with the image bearing member becomes a state in which slipping of a toner readily occurs, and identifies a defective site in the contact portion on the basis of a detected result by the detector.

An image forming apparatus includes a CPU configured to change a parameter value used to control a developer bearing amount and form a plurality of patches for different parameter values changed, and a color sensor configured to measure the plurality of patches thereby acquiring color information thereof. The CPU detects, from values of color information of the plurality of patches, a value of the color information at which a change greater than or equal to a predetermined threshold value occurs, and the CPU sets a parameter used in forming an image based on the detected value of color information.

An image forming apparatus includes an image carrying member, a developing device, a cleaning unit and a processor. The developing device performs development with a developer containing a toner and a lubricant. The processor obtains information on a lubricant amount in the developing device; obtains, with respect to each section formed by dividing a surface of the image carrying member in a rotating shaft direction of the image carrying member, a partial coverage from electrostatic latent image writing information for a predetermined period about the section; sets, for the section having the partial coverage of a predetermined value or less, a developer supply amount for a patch to be formed outside an image forming region on the image carrying member, based on the above information; and causes the developing device to supply the set developer supply amount so that the patch is formed.

An image forming apparatus includes a forming unit, a supply unit, a first measurement unit, a control unit, a second measurement unit, an adjustment unit, and a changing unit. The forming unit forms a toner image on an image carrier using developer which is contained in a developer container and includes toner and a magnetic carrier. The supply unit supplies the toner to the developer container. The first measurement unit measures a density of the toner in the developer contained in the developer container. The control unit controls the supply unit such that the density measured by the first measurement unit approaches a target density. The second measurement unit measures an image density formed by the forming unit. The adjustment unit adjusts a development contrast potential so that a formation density measured by the second measurement unit approaches a predetermined appropriate density with regard to the toner image formed by the forming unit under a predetermined condition. The changing unit is configured to change a target density if the adjustment unit is not able to adjust the development contrast potential so that the formation density measured by the second measurement unit approaches the appropriate density.

An image forming apparatus includes an image forming unit including a photosensitive member, a light source, and a developing roller, and a controller configured to control the image forming unit to form a detection image, obtain density data regarding density levels in a plurality of areas in the detection image at a plurality of positions in a scanning direction in which the photosensitive member is scanned with the light from the light source, generate, based on the density data, a first image forming condition for forming a first test image and a second image forming condition for forming a second test image, the second image forming condition being different from the first image forming condition, and control the image forming unit to form the first test image and the second test image, respectively based on the first image forming condition and the second image forming condition.

An image forming apparatus includes an image forming unit configured to form an image on an intermediate transfer member; a transfer member configured to output a transfer voltage in order to cause a transfer current to flow so as to transfer the image to a sheet; a measurement unit configured to measure a density of the image; and a control unit configured to control the image forming unit to form a test image on the intermediate transfer member based on test image data, control the measurement unit to acquire a measured density of the test image, correct the measured density based on an evaluation value of an electric resistance of a path through which the transfer current flows, and generate data for density correction based on the test image data and a corrected measured density.

An image forming apparatus includes a rotatable image bearing member, an image forming portion, a transfer portion, a cleaning blade, and a controller configured to carry out control so as to execute a predetermined cleaning operation At least in a predetermined range of a leading end portion of the predetermined toner image with respect to a first direction which is a surface movement direction of the image bearing member, when the predetermined toner image is viewed per unit area of 1 mm in each of the first direction and a second direction perpendicular to the first direction, the predetermined toner image includes a plurality of print portions extending along a predetermined direction and formed at different positions with respect to the second direction, and the predetermined direction forms an angle of 30? or less between itself and the first direction.

An image forming apparatus includes an image forming unit configured to form an image on a sheet. The image forming unit includes a photosensitive member; a charger configured to charge the photosensitive member based on a charging potential; an exposure unit configured to expose the photosensitive member charged by the charger to light to form an electrostatic latent image on the photosensitive member, an exposure intensity of the exposure unit being controlled based on an exposure condition; a developing sleeve configured to develop the electrostatic latent image; and one or more processors configured to perform operations including controlling the image forming unit to form a line test image and a width test image.