Abstract: An image forming apparatus includes: a photosensitive drum; a magnetic roller; a transfer belt; a drum cleaning roller for collecting toner on the photosensitive drum and discharging collected toner to the photosensitive drum; a belt cleaner; a waste toner accommodating unit; and a controller configured to perform a printing operation for forming an image on a sheet and a cleaning operation for cleaning the drum cleaning roller. The controller is configured to perform: when performing the printing operation, collecting toner on the photosensitive drum using the drum cleaning roller; and when performing the cleaning operation, discharging the toner on the drum cleaning roller collected in the collecting to the photosensitive drum; transferring the toner on the photosensitive drum onto the transfer belt; and collecting the toner on the transfer belt using the belt cleaner so that the collected toner is accommodated in the waste toner accommodating unit.

Abstract: In an image forming apparatus, an image forming unit configured to form a toner image on a transfer medium includes four sets of a photoconductor drum and a development roller, respectively, for forming toner images of first, second, third and fourth colors, arranged in this order, in a direction opposite to a direction of movement of the transfer medium moving toward a detector configured to detect a toner image formed on the transfer medium. A controller executes a bias-corrective test image forming process in which a first bias-corrective test image of the first color is arranged in a position downstream of other three first bias-corrective test images, and a second bias-corrective test image of the first color is arranged in a position between two first bias-corrective test images selected among other three first bias-corrective test images, in the direction of movement of the transfer medium.

Abstract: There is provided image forming apparatus including: photosensitive member; developing roller configured to supply a developer to the photosensitive member; belt to which a developer image is to be transferred from the photosensitive member; sensor; and controller configured to execute a developing bias correcting process for correcting a developing bias to be applied to the developing roller. The developing bias correcting process includes: a setting process for setting testing biases, all of the testing biases being smaller than an old developing bias; a forming process for forming developer images on the belt by using the testing biases set in the setting process; a detecting process for detecting densities of the developer images formed in the forming process by the sensor; and a calculating process for calculating the developing bias based on the densities of the developer images detected in the detecting process.

Abstract: In an image forming apparatus, an image forming unit configured to form a toner image on a transfer medium includes four sets of a photoconductor drum and a development roller, respectively, for forming toner images of first, second, third and fourth colors, arranged in this order, in a direction opposite to a direction of movement of the transfer medium moving toward a detector configured to detect a toner image formed on the transfer medium. A controller executes a bias-corrective test image forming process in which a first bias-corrective test image of the first color is arranged in a position downstream of other three first bias-corrective test images, and a second bias-corrective test image of the first color is arranged in a position between two first bias-corrective test images selected among other three first bias-corrective test images, in the direction of movement of the transfer medium.

Abstract: There is provided image forming apparatus including: photosensitive member; developing roller configured to supply a developer to the photosensitive member; belt to which a developer image is to be transferred from the photosensitive member; sensor; and controller configured to execute a developing bias correcting process for correcting a developing bias to be applied to the developing roller. The developing bias correcting process includes: a setting process for setting testing biases, all of the testing biases being smaller than an old developing bias; a forming process for forming developer images on the belt by using the testing biases set in the setting process; a detecting process for detecting densities of the developer images formed in the forming process by the sensor; and a calculating process for calculating the developing bias based on the densities of the developer images detected in the detecting process.

Abstract: An image forming apparatus comprises, a collecting member configured to collect waste toner adhered on a conveying belt, a cleaning voltage supplier configured to supply a cleaning voltage to the collecting member, a container having a first contact and configured to contain the collected waste toner, and an attachment part having a second contact configured to contact the first contact. The container is detachably attached to the attachment part. The image forming part further comprises a switch configured such that a switching state is switchable based on an amount of the waste toner in the container. The image forming apparatus generates a detection signal based on a voltage at the second contact to determine whether an amount of the waste toner in the container is greater than a particular amount.

Abstract: In response to determining that image forming in a color mode is performed on a first sheet and then image forming in a monochrome mode is successively performed on the second sheet, perform charging bias reduction processing gradually reducing a charging bias from first to second charging bias and developing bias reduction processing of gradually reducing a developing bias from first to second developing bias during a first inter-sheet period after the first sheet passes a first photosensitive drum and before the second sheet reaches the first photosensitive drum, and perform separation processing such that an execution period of the separation processing overlaps at least one of an execution period of the charging bias reduction processing and an execution period of the developing bias reduction processing, the separation processing being processing of controlling a moving mechanism to move a first developing roller from a contact position to a separation position.

Abstract: In response to determining that image forming in a color mode is performed on a first sheet and then image forming in a monochrome mode is successively performed on the second sheet, perform charging bias reduction processing gradually reducing a charging bias from first to second charging bias and developing bias reduction processing of gradually reducing a developing bias from first to second developing bias during a first inter-sheet period after the first sheet passes a first photosensitive drum and before the second sheet reaches the first photosensitive drum, and perform separation processing such that an execution period of the separation processing overlaps at least one of an execution period of the charging bias reduction processing and an execution period of the developing bias reduction processing, the separation processing being processing of controlling a moving mechanism to move a first developing roller from a contact position to a separation position.

Abstract: According to the present disclosures, a first end of a detection switch is connected to a first electrode and a second end is connected to a collecting roller. A detection signal generator is configured to generate a detection signal based on voltage of an attachment part side first electrode connected to the first electrode. A controller determines whether amount of adhered substances in a waste toner box becomes larger than a particular amount based on the detection signal.

Abstract: In an image forming apparatus, a plurality of light emitting portions arrayed in an array direction. A lens array has a length in the array direction longer than a length in a direction orthogonal to the array direction. A controller is configured to perform: converting a reference printing pattern including a plurality of first linear patterns to a detection pattern including a plurality of second linear patterns, each of the plurality of first linear patterns forming a first angle with respect to a reference line parallel to the array direction, each of the plurality of second linear patterns forming a second angle smaller than the first angle with respect to the reference line; forming a detection pattern image on a transfer medium; detecting a print density of the detection pattern image with a sensor; and setting an image formation condition according to the print density detected by the sensor.

Abstract: There is provided an image forming apparatus including: an intermediate transfer belt; a photosensitive drum; a primary transfer member; a secondary transfer member; a first backup member; a first power supply electrically connected to the primary transfer member and to the secondary transfer member; and a first resistor electrically connected to the first power supply and to the primary transfer member. A first current route, in which the first resistor, the primary transfer member, and the photosensitive drum are connected in series in that order, is connected to the first power supply and to a basis potential. A second current route, in which the secondary transfer member and the first backup member are connected in series, is connected to the first power supply and to the basis potential. The first current route is connected in parallel to the second current route.

Abstract: In an image forming apparatus, a plurality of light emitting portions arrayed in an array direction. A lens array has a length in the array direction longer than a length in a direction orthogonal to the array direction. A controller is configured to perform: converting a reference printing pattern including a plurality of first linear patterns to a detection pattern including a plurality of second linear patterns, each of the plurality of first linear patterns forming a first angle with respect to a reference line parallel to the array direction, each of the plurality of second linear patterns forming a second angle smaller than the first angle with respect to the reference line; forming a detection pattern image on a transfer medium; detecting a print density of the detection pattern image with a sensor; and setting an image formation condition according to the print density detected by the sensor.

Abstract: An image forming apparatus includes a belt, a first process unit, a second process unit, and a controller configured to form a toner image based on a first pattern on a first photoconductive body of the first process unit. In addition, the controller is configured to transfer the toner image onto the belt, form an electrostatic latent image based on a second pattern on a second photoconductive body of the second process unit such that the electrostatic latent image formed on the second photoconductive body positionally coincides with the toner image transferred onto the belt in a contact position where the second photoconductive body contacts the belt, and convey the electrostatic latent image formed on the second photoconductive body to the contact position without developing the electrostatic latent image with toner.

Abstract: There is provided an image forming apparatus including: an intermediate transfer belt; a photosensitive drum; a primary transfer member; a secondary transfer member; a first backup member; a first power supply electrically connected to the primary transfer member and to the secondary transfer member; and a first resistor electrically connected to the first power supply and to the primary transfer member. A first current route, in which the first resistor, the primary transfer member, and the photosensitive drum are connected in series in that order, is connected to the first power supply and to a basis potential. A second current route, in which the secondary transfer member and the first backup member are connected in series, is connected to the first power supply and to the basis potential. The first current route is connected in parallel to the second current route.

Abstract: An image forming apparatus includes a belt, a plurality of image forming devices including a photosensitive member, a developing device, a transfer device and a blade, and a control device configured to form a pattern image on a first photosensitive member, when an image to be printed on a sheet is not formed, by applying a developing voltage to a first developing device, an absolute value thereof is greater than that when an image to be printed on a sheet is formed, transfer the pattern image onto the belt and apply a transfer voltage or transfer current having the same polarity as that applied to a second transfer device when an image to be printed on a sheet is formed to the second transfer device when the pattern image to be conveyed by the belt passes the second transfer device.

Abstract: An image forming apparatus includes an image forming device for forming a pattern image having unit images on a photosensitive member, a sensor for irradiating the pattern image with light and detecting reflected light, and a controller for controlling the image forming device to form a pattern image for printing used when printing and a pattern image for detection to be detected by the sensor on the photosensitive member. A first pattern image for printing includes a predetermined number of first unit images arranged to be spaced from each other, each of the first unit images being smaller than a predetermined size. A first pattern image for detection corresponding to the first pattern image for printing includes more than the predetermined number of the first unit images arranged to be spaced from each other.

Abstract: An image forming apparatus includes a belt, a plurality of image forming devices including a photosensitive member, a developing device, a transfer device and a blade, and a control device configured to form a pattern image on a first photosensitive member, when an image to be printed on a sheet is not formed, by applying a developing voltage to a first developing device, an absolute value thereof is greater than that when an image to be printed on a sheet is formed, transfer the pattern image onto the belt and apply a transfer voltage or transfer current having the same polarity as that applied to a second transfer device when an image to be printed on a sheet is formed to the second transfer device when the pattern image to be conveyed by the belt passes the second transfer device.

Abstract: An image forming apparatus includes a belt, a first process unit, a second process unit, and a controller configured to form a toner image based on a first pattern on a first photoconductive body of the first process unit, transfer the toner image onto the belt, form an electrostatic latent image based on a second pattern on a second photoconductive body of the second process unit such that the electrostatic latent image formed on the second photoconductive body positionally coincides with the toner image transferred onto the belt in a contact position where the second photoconductive body contacts the belt, and convey the electrostatic latent image formed on the second photoconductive body to the contact position without developing the electrostatic latent image with toner.

Abstract: An image forming apparatus includes a belt, a plurality of image forming devices including a photosensitive member, a developing device, a transfer device and a blade, and a control device configured to form a pattern image on a first photosensitive member, when an image to be printed on a sheet is not formed, by applying a developing voltage to a first developing device, an absolute value thereof is greater than that when an image to be printed on a sheet is formed, transfer the pattern image onto the belt and apply a transfer voltage or transfer current having the same polarity as that applied to a second transfer device when an image to be printed on a sheet is formed to the second transfer device when the pattern image to be conveyed by the belt passes the second transfer device.

Abstract: An image forming apparatus includes a controller configured to apply a charging bias to a charger during image formation on a photoconductive body, an absolute value of the charging bias being a first absolute value. The controller applies a development bias to a development roller during the image formation, places the development roller in a development position during the image formation, after the image formation, reduces the absolute value of the charging bias to a second absolute value less than the first absolute value, after reducing the absolute value of the charging bias, separates the development roller away from the photoconductive body and places the development roller in a non-development position, and after placing the development roller in the non-development position, stops applying the development bias to the development roller.