A method of controlling toner development during a life of an imaging unit in an image forming device by determining whether an end of life of the imaging unit has been reached and upon a positive determination, performing at least one of incrementally lowering a target toner mass to be measured by a toner patch sensor and incrementally reducing the magnitude of voltage biases applied to at least one of the magnetic roll and the charging roll of the imaging forming device. Performing the acts of incrementally lowering and reducing are repeated until the imaging unit is replaced. The method reduces the risk of damage to the image forming device due to carrier bead development while allowing for printing to occur.

An image forming apparatus includes a photoconductor, a light source, an optical scanning device, an image bearer, an image density sensor, an image processing circuit, and a light source driver. The plurality of images are formed with a plurality of light intensities and a plurality of image area rates on the image bearer. The image density sensor detects a plurality of image densities of the plurality of images at a plurality of positions in a main scanning direction. The image processing circuit determines a light intensity correction value to correct an image density of a target image in the main scanning direction based on the plurality of light intensities, image area rates, image densities, and positions, and the image area rate of the target image, and outputs a control signal to adjust a light intensity. The light source driver adjusts the light intensity based on the control signal.

To prevent the detection accuracy from deteriorating due to stray light, an optical apparatus includes the following configuration. The optical apparatus includes a light-emitting member, a light-receiving member, and a substrate on which the light-emitting member and the light-receiving member are mounted. The substrate includes a plate-like substrate layer and a plate-like conductive layer. The optical apparatus further includes a light-shielding member disposed between the light-receiving member and the light-emitting member and inserted in a through-hole of the substrate provided between the light-receiving member and the light-emitting member. The light-receiving member receives reflected light from a portion to be irradiated with the light emitted from the light-emitting member. The conductive layer is excellent in light-shielding property compared to the substrate layer. The conductive layer is exposed to an inner cylindrical surface of the through-hole.

An image forming system includes: a density detecting section that detects the density of a toner image formed on an image bearing member by an image forming section, the density being detected as an output image density; a hardware processor which performs; tone correction in accordance with input-output characteristics data indicating the relationship between an input image density and an output image density, the input image density being the image density of a tone component included in the input image data, the output image density being detected by the density detecting section in accordance with the tone component; determining whether there is a missing tone component in the input image data; and complementing the input-output characteristics data corresponding to a missing tone component, when it is determined that there is the missing tone component.

An image forming apparatus includes a converting unit configured to convert image data based on a conversion condition; an image forming unit; a measurement unit; and a controller configured to control the image forming unit to form a plurality of measurement images including a first measurement image and a second measurement image. The controller obtains first output characteristics based on a current measurement result of the first measurement image and a previous measurement result of the second measurement image to generate the conversion condition, and the controller obtains second output characteristics based on a current measurement result of the second measurement image and a previous measurement result of the first measurement image to generate the conversion condition.

A method of controlling a color-tone density (CTD) of an image forming apparatus including a plurality of developers configured to circularly perform a developing operation. The method includes developing test patches on an OPC sequentially from a developer to be developable preferentially, measuring CTDs of the developed test patches, and controlling a development variable using the measure CTDs.

An image formation apparatus includes: an image carrier; a developing device which develops an electrostatic latent image formed on the image carrier as a toner image; a transfer device which transfers the toner image to a medium; a cleaning device which recovers toner remaining on the image carrier after the toner image is transferred; and a lubricant application adjustment mechanism which applies a lubricant on the image carrier and recovers toner present on the image carrier upstream of the cleaning device; and a controller which controls the lubricant application adjustment mechanism. The controller causes the lubricant application adjustment mechanism to recover more toner when the toner image formed on the image carrier has a larger image area ratio.

A method of controlling toner development during a life of an imaging unit in an image forming device by determining whether an end of life of the imaging unit has been reached and upon a positive determination, performing at least one of incrementally lowering a target toner mass to be measured by a toner patch sensor and incrementally reducing the magnitude of voltage biases applied to at least one of the magnetic roll and the charging roll of the imaging forming device. Performing the acts of incrementally lowering and reducing are repeated until the imaging unit is replaced. The method reduces the risk of damage to the image forming device due to carrier bead development while allowing for printing to occur.

An image forming apparatus includes a detecting portion to detect a test toner image formed on an image bearing member, and a shielding member is provided between the detecting portion and the image bearing member and reciprocates between first and second positions. A first opposing portion includes a first member opposed to the image bearing member and provided at a position opposing the image bearing member through an opening in a process of movement of the shielding member, an electrically grounded electroconductive member is disposed in a side opposite a side of the first member opposed to the image bearing member; and a second opposing portion is disposed opposed to the image bearing member and provided at position opposing the image bearing member through the opening in the process of movement of the shielding member from the second position to the first position.

An image forming apparatus determines a toner density erroneous detection state based on a patch image density in patch detection auto toner replenishing and, when the toner density erroneous detection state is determined, offsets a target toner density by the amount of erroneous detection so that the actual toner density becomes a desired toner density.