| Patent application number | Description | Published |
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| 20100196056 | DEVELOPING DEVICE, IMAGE FORMING APPARATUS, AND CLEANING METHOD FOR THE DEVELOPING DEVICE - A developing device includes a developer tank for housing a two-component developer containing toner and magnetic carrier; a first conveying portion having a first rotary shaft rotatable about its axis and a first screw blade which surrounds the first rotary shaft and rotates together with the first rotary shaft and contains a ferromagnetic substance; a second conveying portion having a second rotary shaft rotatable about its axis and a second screw blade which surrounds the second rotary shaft and rotates together with the second rotary shaft and contains a ferromagnetic substance; a first electromagnet for magnetizing the first screw blade; and a second electromagnet for magnetizing the second screw blade. | 08-05-2010 |
| 20110058824 | IMAGE FORMING APPARATUS - An image forming apparatus includes: a developing device; a toner supply device that supplies toner to the developing device; a toner concentration controller that directs the toner supply device to perform toner supply to the developing device; and a toner empty determiner for determining that no toner is left in the toner supply device. The developing device includes a toner supply detecting sensor that detects whether toner is supplied from the toner supply device into the developer container, in the developer container. The toner concentration controller gives directions to perform the toner supply when the toner concentration of the developer in the developing device has become lower than a predetermined level. The toner empty determiner determines that the toner supply device has no toner left therein when no effect of the toner supply is detected by the toner supply detecting sensor after the toner supply is directed by the toner concentration controller. The toner supply detecting sensor is disposed in the preliminary agitating section. | 03-10-2011 |
| 20110123204 | IMAGE FORMING APPARATUS AND TONER SUPPLY METHOD - An image forming apparatus includes a developing device having a toner supply sensor, a toner supply device supplying toner to the developing device, a toner supply controller controlling toner supply from the toner supply device to the developing device based on predetermined conditions, a toner empty determiner determining whether toner is present inside the toner supply device. In the image forming apparatus, the toner supply device includes a storage for recoding multiple measured values of toner supply detected by the toner supply sensor, and the toner supply controller corrects the amount of toner supply, based on the moving average of multiple measured values of the amount of toner supply. | 05-26-2011 |
| 20110222872 | IMAGE FORMING APPARATUS - An image forming apparatus includes: a developing device; a toner supply device that supplies toner to the developing device; and a toner supply detecting sensor that detects whether toner is supplied into the developing device; and a toner empty determination controller for determining that the toner inside the toner supply device is used up. Toner empty determination controller, based on the output result from the toner supply detecting sensor, modifies the toner empty determining threshold, based on which toner empty is determined. | 09-15-2011 |
| 20110255888 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - An image forming apparatus includes: a developing device having a developing vessel, a developing roller and a toner supply port; a toner supply device; a toner supply detecting sensor for detecting the toner concentration inside the developing vessel; a toner concentration controller for directing toner supply; a toner empty detector; and a sheet conveyance detecting sensor. The toner concentration controller has a toner supply device control function; and a toner supply stopping function of stopping toner supply when the last sheet of image printout being executed has passed by the predetermined position in the sheet conveyance path. | 10-20-2011 |
| 20110262155 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD USING THE SAME - An image forming apparatus can prevent printed images from being degraded in image quality due to failure of the toner concentration to fall within a proper range, by correcting the deviations of the amount of toner consumption and the amount of toner supply depending on the individuality of each image forming apparatus and that enables exact identification of the cause of a fault associated with toner concentration, as well as providing an image forming method using the apparatus. A toner supply device supplies toner to a developing vessel through an opening in accordance with an instruction from a controller. The presence or absence of toner falling is detected based on the variation of the output from a magnetic permeability sensor when toner is supplied. The controller monitors the output voltage level of the magnetic permeability sensor and adjusts the input gain in accordance with the output voltage level to thereby control toner concentration. | 10-27-2011 |
| Patent application number | Description | Published |
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| 20080219684 | IMAGE FORMING APPARATUS - An image forming apparatus is provided which is capable of forming higher-quality images by detecting a toner concentration with higher accuracy to attain appropriate toner supply and image density. A value obtained by adding a correction value based on a temperature, humidity, a print coverage, or the like to a developer concentration adjustment value is set as a control voltage value Vc which is to be inputted to a toner concentration sensor, and an output value of the toner concentration sensor is detected for each of process speeds. A difference between the output value detected and a value at reference process speed is calculated and based on the difference, a correction value is further calculated. Such another calculation of the correction value with use of the output value detected allows for highly accurate correction. | 09-11-2008 |
| 20090110414 | IMAGE STABILIZING APPARATUS AND IMAGE FORMING APPARATUS - There is provided an image stabilizing apparatus which is capable of keeping a toner concentration and a printing density constant when, toner consumption is small, and further which is systematically simple. The image stabilizing apparatus comprises a control portion for controlling a toner replenishment amount in a toner replenishing apparatus depending on a toner concentration detected by a toner concentration sensor and a print coverage of a document detected by a print coverage detecting portion, and controlling, when the print coverage of the document detected by the print coverage detecting portion is less than a predetermined value and such documents continue, so as to discharge a predetermined amount of toner to the image bearing member by developing forcibly, and then replenish the same amount of toner as the predetermined amount by the toner replenishing apparatus. | 04-30-2009 |
