Patent application number | Description | Published |
20090324267 | IMAGE FORMING APPARATUS AND IMAGE-DENSITY CONTROL METHOD - An image forming apparatus forms a plurality of tone patterns of different colors, each of which containing a plurality of toner patches having different toner densities. Some of the toner patches in each of the tone patterns are formed with a predetermined fixed developing bias and the rest of the toner patches in each of the tone patterns are formed with developing biases set based on previous developing biases that have been obtained through a previous control process. The largest toner density of the toner patches in each of the tone patterns is determined based on a magnitude relation of previous index values obtained through the previous control process. | 12-31-2009 |
20100092188 | IMAGE FORMING APPARATUS - An image forming apparatus includes a problem-occurrence determining unit, a problem-occurrence area determining unit, and a notifying unit. If the problem-occurrence determining unit determines that a problem has occurred in an image forming process, the problem-occurrence area determining unit determines whether the problem is caused by a toner filling process on the basis of toner-filling control data and toner-supply control data. The notifying unit then notifies the determination as to whether the problem is caused by the toner filling process. | 04-15-2010 |
20100278549 | IMAGE FOMRING APARATUS AND METHOD OF ADJUSTING CHARGE BIAS - An image forming apparatus includes an image carrier configured to carry an image and a charger to which a direct current voltage overlapped with an AC voltage is applied as a charging bias to charge the image carrier. The charger is positioned in contact or contactlessly with the image carrier. The AC voltage applied to the charger in an adjustment of the AC voltage is not less than twice a charging start voltage Vth at which the image carrier starts to be charged. | 11-04-2010 |
20120315056 | DIFFUSE REFLECTION OUTPUT CONVERSION METHOD, ATTACHED POWDER AMOUNT CONVERSION METHOD, AND IMAGE FORMING APPARATUS - In an embodiment, a diffuse reflection output conversion method is executed in an apparatus detecting a plurality of gradation patterns. The apparatus includes a light emitter and light receiver, and detects specular reflection and diffuse reflection simultaneously. A region before specular reflection saturation is a region where the specular reflection component decreases and saturates at minimum level. A diffuse reflection detector is calibrated by: obtaining a diffuse reflection output resulting from an amount of attached powder at a border between the region before specular reflection saturation and the region after specular reflection saturation; calculating a ratio between the diffuse reflection output and a reference diffuse reflection output calculated in advance as a calibration coefficient; and multiplying a diffuse reflection output obtained from the gradation patterns by the calibration coefficient calculated at the calculating. | 12-13-2012 |
20130004207 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device for developing an electrostatic latent image on an image bearing member including a developer bearing member opposed to the image bearing member to bear thereon a developer including a toner and a magnetic carrier; a developer containing part to contain the developer to supply the developer to the developer bearing member; an agitating or feeding member to agitate or feed the developer in the developer containing part; a magnetic permeability sensor to measure magnetic permeability of the developer to determine toner concentration of the developer; a developer feeder; a feeding member to feed the developer to the developer containing part through the developer feeder; and a driver to drive the feeding member independently of the agitating or feeding member. The magnetic permeability sensor is arranged on the developer feeder. | 01-03-2013 |
Patent application number | Description | Published |
20080205923 | IMAGE FORMING APPARATUS AND IMAGE DENSITY CONTROL METHOD - An image forming apparatus includes an image carrier configured to carry an electrostatic latent image, a developing device configured to develop the electrostatic latent image with a two-component developer including toner and magnetic carrier, a toner supplier configured to supply the toner to the developing device, a toner concentration detector configured to detect toner concentration in the two-component developer inside the developing device, and a controller. The controller is configured to detect first information to determine toner replacement amount in the developing device during a predetermined time period and second information to determine a charge characteristic of the toner in the developing device, change a toner concentration control reference value based on the first information and the second information, and control the toner concentration based on an output from the toner concentration detector and the toner concentration control reference value. | 08-28-2008 |
20080253793 | IMAGE FORMING APPARATUS CAPABLE OF EFFICIENT TONER CONCENTRATION CONTROL - An image forming apparatus includes an image forming unit configured to form a plurality of toner images on an image carrier, an optical detector configured to detect reflection light from the toner image, and dedicated to detect infrared rays and near-infrared rays, and a controller configured to perform a predetermined control using a detection results of the optical detector. Gradation pattern that is comprised of a plurality of toner patches formed in the image forming unit with an image forming condition to have different adhesive amounts, and is formed of at least two colors, and detection values detected by the optical detector are used for the predetermined control. | 10-16-2008 |
20090110413 | IMAGE FORMING APPARATUS AND IMAGE DENSITY CONTROL METHOD - An image forming apparatus and an image density control method for controlling image density in the image forming apparatus, involving adjusting a toner concentration control reference value in accordance with an amount of the toner replaced in a developing device so as to adjust the image density to maintain a consistent developability and changing image forming intervals in accordance with an amount of the toner replaced in the developing device during continuous printing operation. | 04-30-2009 |
20090190960 | PROCESS CARTRIDGE INCLUDING DEVELOPING UNIT AND INCORPORATED IN IMAGE FORMING APPARATUS - A process cartridge for use in an image forming apparatus includes an image bearing member and a developing unit. The developing unit includes a developer bearing member to bear developer including toner and carrier, a casing forming a developer container containing the developer, a screw having a shaft with a spiral screw blade, a toner density sensor to detect a density of the toner on a detection surface, and a detection surface agitating member fixedly mounted on the shaft of the screw at a position facing a detection surface to scrape away the developer accumulated on the detection surface as the screw rotates. The detection surface agitating member includes an elastic sheet elastically deformable to scrape away the developer accumulated on the detection surface and disposed at a substantially same angle to an axial direction of the shaft of the screw as the spiral screw blade. | 07-30-2009 |
20090263150 | IMAGE FORMING APPARATUS AND IMAGE QUALITY CORRECTION METHOD USED THEREIN - An image forming apparatus includes multiple image forming units to form different single-color images with respective different color developers and a control system to selectively perform a multicolor image forming operation, a specific-color image forming operation, a multicolor image quality correction operation, and a specific-color image quality correction operation. The control system includes an image formation mode detection unit to ascertain which of the multicolor image forming operation and the specific-color image forming operation is performed prior to a request for image quality correction; and a correction instruction unit to order the multicolor image quality correction operation when the multicolor image quality correction operation is requested, the specific-color correction operation when the specific-color image quality correction operation is requested after the specific-color image forming operation, and the multicolor image quality correction operation when the specific-color image quality correction operation is requested after the multicolor image forming operation. | 10-22-2009 |
20090279907 | REUSE METHOD AND IMAGE FORMING APPARATUS - In a reuse method for reusing a reusable device and a sensor of a first image forming apparatus having a first process linear velocity in a second image forming apparatus having at least one second process linear velocity different from the first process linear velocity, the reusable device and the sensor are installed in the first image forming apparatus, and when the first image forming apparatus switches from the first process linear velocity to the second process linear velocity at an initial state before the reusable device is used, output of the sensor at the second process linear velocity is measured. When information on the output of the sensor at the second process linear velocity is stored, the reusable device and the sensor are removed from the first image forming apparatus and installed in the second image forming apparatus. | 11-12-2009 |
20110110689 | TONER SUPPLYING DEVICE AND IMAGE FORMING APPARATUS USING SAME - A toner supplying device including a secondary toner container, a first feeding member performing a first feeding operation of feeding toner from a toner container to the secondary container on demand, a second feeding member performing a second feeding operation of feeding the toner from the secondary container to a developing device on demand, and a toner supply controller controlling the amount of the toner in the secondary container to be greater than a predetermined amount. The controller performs first control in which when the first feeding operation is performed, the amount of the toner fed in the second feeding operation per unit of time is decreased, or second control in which when the amount of the toner fed in the second feeding operation is greater than a predetermined amount, the amount of the toner fed in the first feeding operation per unit of time is decreased. | 05-12-2011 |