Patent application number | Description | Published |
20100061750 | IMAGE FORMING APPARATUS - An image forming apparatus includes a image bearing member (drum); a developing device for forming a developing portion at which an electrostatic latent image formed on the drum is developed with toner; a toner supply device for supplying toner to the developing device; a density detecting portion for detecting a density of a control toner image formed on the drum; a toner ratio detecting portion for detecting a toner ratio in a two component developer contained in the developing device; a transfer member for forming a transfer portion; a charging member for electrically charging the toner image formed by the developing device by being supplied with a bias of an identical polarity to a charge polarity of the toner; an adjusting portion for adjusting an amount of the toner supplied from the toner supply device so that the toner ratio is below a preset lower limit when the toner ratio detected by the toner ratio detecting portion reaches the lower limit; and a bias determining portion for determining, after the adjustment by the adjusting device, a condition of a bias to be applied to the charging member on the basis of a detection result of the density detecting portion with respect to the density of the control toner image formed on the drum. | 03-11-2010 |
20120155898 | IMAGE FORMING APPARATUS - The present image forming apparatus forms a reference developing material image on an image carrier using an exposure unit and a developing unit before executing auto tone correction processing, and detects the density of the reference developing material image formed on the image carrier. If the detection result indicates that the toner charge amount of the developing material contained in the developing unit is within a predetermined range, auto tone correction processing is executed, whereas if the detection result of the density detecting unit indicates that the toner charge amount of the developing material contained in the developing unit is outside the predetermined range, adjustment processing for adjusting the toner charge amount of the developing material contained in the developing unit to be within the predetermined range is executed before execution of auto tone correction processing. | 06-21-2012 |
20130058669 | IMAGE FORMING APPARATUS - An image forming apparatus, includes: an image forming portion; a supplying device for supplying a toner; a transfer device capable of transferring the toner image from the image forming portion onto a toner image receiving member; a first detecting portion for detecting a transfer current of the transfer device; a second detecting portion for detecting information on a toner amount of the transferred toner image; and a controller for controlling, during non-image formation, a supplying operation of the supplying device on the basis of a detection result of the first detecting portion when a toner image for measurement formed at the image forming portion is transferred by the transfer device at a transfer voltage lower than a discharge start voltage and on the basis of a detection result when the toner image for measurement transferred on the toner image receiving member is detected by the second detection portion. | 03-07-2013 |
20130136464 | IMAGE FORMING APPARATUS - Provided is an image forming apparatus including: photosensitive drums; electrostatic latent image forming units; developing sleeves; patch detection sensors which detect image densities of the toner images formed by the electrostatic latent image forming units; and toner replenishment units which replenish the developing sleeves with the toner based on the detection results of the patch detection sensors. Further, controllers are provided to make a control such that the rotation speeds of the developing sleeves at the time of forming the reference toner image is higher than the rotation speeds of the developing sleeves at the time of forming a normal image. | 05-30-2013 |
20150049364 | IMAGE FORMING APPARATUS - An image forming apparatus includes: an image bearing member; a developing device; a supply device that supplies the developing device with toner; a density detector that detects information about a toner density serving as a ratio of toner and carrier of the developer of the developing device; and a controller that is able to execute a remaining amount determination mode which interrupts the image forming operation and performs a toner supply operation on the developing device from the supply device, based on the detection result of the density detector, wherein the controller at least selectively executes a first state that immediately prohibits the image formation, a second state that allows the image forming operation, and a third state that executes the mode again, based on the detection result of the density detector acquired after the start of execution of the mode. | 02-19-2015 |
20150050036 | IMAGE FORMING APPARATUS - An image forming apparatus includes: an image bearing member; a developing device; a supply device which supplies toner to the developing device; a density detector which detects information about a toner density as a ratio of toner and carrier of the developer of the developing device; and a controller which interrupts an image forming operation and is capable of executing a forced supply mode of performing the toner supply to the developing device from the supply device, based on first information of at least one of detection results of the density detector and information about a toner consumption, second information about the amount of supply operation supplied by the supply device, in which the controller determines whether or not to execute the forced supply mode, and third information about an accumulated value of the amount of toner consumption after the forced supply mode executed last time. | 02-19-2015 |