Abstract: In an image forming apparatus and an image density control method that are capable of suppressing the amount of toner consumed for a purpose other than image formation and responding to variation in the development ability of a development device due to environmental variation and the like such that a constant image density is obtained, the image density is maintained at a substantially fixed level by first target output value correcting means in accordance with a toner replacement amount and without consuming toner, and adjustment of the image density accompanying variation in the development ability due to environmental variation and the like is dealt with by second target output value correcting means in accordance with a toner pattern detection result.

Abstract: 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.

Abstract: In an image forming apparatus, a toner image formed on a photosensitive drum is primarily transferred onto an intermediate transfer belt. The toner image on the intermediate transfer belt is secondarily transferred onto a transfer material by a secondary transfer roller in contact with the intermediate transfer belt. A relation A>B>C is satisfied, where A is a width of the intermediate transfer member, B is a width of the secondary transfer member, and C is a width of the transfer material. The intermediate transfer member includes a patch-pattern forming area that is not contacted by the secondary transfer member. The image forming apparatus includes a reflection-type photosensor that detects a patch pattern formed in the patch-pattern forming area.

Abstract: A developing device including a developer bearing member configured to configured to bear thereon a developer including a toner and a magnetic carrier to develop an electrostatic image on an image bearing member with the developer; a developer container configured to contain and feed the developer to the developer bearing member; a toner concentration sensor configured to detect a concentration of the toner in the developer in the developer container and output a signal depending on the detected toner concentration; and a characteristic information storage device configured to store a characteristic of the toner concentration sensor, wherein the sensor information storage device is separated from the toner concentration sensor. A process unit including an image bearing member and the developing device. An image forming apparatus including an image bearing member, the developing device and a controller.

Abstract: An image forming apparatus including a latent image bearing member; a developing device configured to develop a latent image on the image bearing member with a two-component developer; a development potential forming device configured to form a development potential; a toner replenishing device configured to supply the toner to the developing device; a toner concentration detecting device configured to detect and output the concentration of the toner in the developer; a toner concentration controlling device configured to compare the toner concentration output with a toner concentration target to control the toner concentration; an information detecting device configured to obtain information to determine the replacement amount of the toner in the developing device in a predetermined period of time; and a development potential correcting device configured to adjust the development potential on the basis of the information obtained by the information detecting device.

Abstract: An image forming apparatus includes at least one image bearing member, an intermediate transfer member, a secondary transfer member, and at least one optical sensor. In the image forming apparatus, it is determined that output values of the respective amounts of toner detected by the at least one optical sensor are affected by an impact caused due to a separation of the secondary transfer member from the intermediate transfer member and the output values are ignored as image adjustment input information, when the secondary transfer member separates from the intermediate transfer member during any of writing, developing, and transferring the plurality of image adjustment patterns, if the output values fall outside a given range and an interval between the output values of adjacent image bearing members is substantially equal to a distance between the two adjacent image bearing members for the primary transfer.

Abstract: A device for detecting image information includes an intermediate transfer member configured to hold a pattern image; a detecting unit configured to optically detect the pattern image; a secondary transfer unit configured to contact with and separate from the intermediate transfer member; and a control unit that controls the secondary transfer unit in such a manner that the secondary transfer unit does not contact the intermediate transfer member while the detecting unit is detecting the pattern image, and that controls the secondary transfer unit in such a manner that the secondary transfer unit contacts the intermediate transfer member after the detecting unit finishes detection of the pattern image.

Abstract: An image forming apparatus includes an image forming mechanism and a control device. The image forming mechanism performs an image forming operation under predetermined image forming conditions, and includes an image carrying member for forming an electrostatic latent image thereon, a development device for developing the electrostatic latent image into a toner image, and a transfer device for transferring the toner image to a recording medium. The control device controls an amount of toner replenished to the development device, sets a developer mixing time for evenly mixing developer in the development device, causes the development device to mix the developer for the set developer mixing time, causes the image forming mechanism to form toner image patterns, detects the toner image patterns, and determines the predetermined image forming conditions based on the detection of the toner image patterns. An image forming method is also described.

Abstract: An image forming apparatus includes an image forming mechanism and a process controller. The process controller is configured to instruct the image forming mechanism to perform an image forming operation and a control operation of image forming process conditions. The control operation includes at least two phases each executable at an individual time. The process controller instructs the image forming mechanism to perform the control operation by executing the at least two phases in order of execution frequency from the highest execution frequency to the lowest execution frequency, and discontinue sequential execution of the at least two phases in accordance with an image output command to preferentially perform the image output operation in accordance with the image output command. An image forming method is also described.

Abstract: An image forming apparatus is configured that a developing unit develops a latent image with a toner, which is controlled by a toner-supply control unit based on a deference between a toner-density of the toner that is supplied to the developing unit and a reference-value. A reference-value determining unit determines the reference-value. A condition determining unit determines whether a predetermined condition is satisfied. The reference-value determining unit updates the reference-value with a different reference-value when the condition determining unit determines that the predetermined condition is satisfied.

Abstract: An image forming apparatus includes an image bearing member, an image forming mechanism configured to perform an image formation by performing a first image forming operation to form a first image on the image bearing member and an image transferring operation to transfer the first image onto a recording member, and an image quality controlling mechanism configured to perform an image control by performing a second image forming operation to form a second image on the image bearing member and an image controlling operation to control an image quality according to the second image. The image quality controlling mechanism determines an operation condition of starting the image control according to first information of operations during the image formation and second information of operations during the image control, when the second image forming operation is performed during the first image forming operation.

Abstract: An image density control method for an image forming apparatus in which, in order to keep the development capability constant over time, the toner density in the developer is manipulated to an appropriate range by changing the toner density control reference value in accordance with the toner replacement amount in a fixed time period by ascertaining changes in the image coverage of the output images, and by changing the image forming conditions at predetermined execution intervals.

Abstract: An image forming device includes a toner pattern forming unit that forms a first toner pattern and a second toner pattern downstream of the first toner pattern along a direction of advance of the transfer belt on the transfer belt. The first toner pattern is configured to include color patches of which a color density gradually differs so that, when detected by a sensor, a fluctuation of the toner density is adjusted by a feedback data. The second toner pattern is configured to prevent a cleaning blade from being twisted by a friction of an intermediate belt due to the toner lubrication.

Abstract: An image forming apparatus, which comprises a toner density detection device for detecting the density of a toner inside a developing device, acquires the number of pixels from inputted image information, calculates the toner replenishment amount from the toner density detection value and the information on the pixels, and thereby performs replenishment control so that excessive replenishment or insufficient replenishment of the toner is not caused. The upper limit value of the amount of toner to be replenished at once to the developing device is changed in accordance with the amount of information on an input image such as the image area, pixels of the input image.

Abstract: An image forming apparatus in which a predetermined image density can be obtained by correcting a toner density control target value without consuming toner. The toner density of the developer is controlled so that an output value Vt of a magnetic permeability sensor approaches a target output value Vtref. In addition, the target output value Vtref is corrected in accordance with image coverage history information of output images transferred to a transfer paper and image coverage ratio history information of output images determined from the image coverage thereof and the size of the transfer paper. This history information comprises, for example, a cumulative average value of the image coverage or the image coverage ratio per transfer paper. It may also comprise a moving average value of the image coverage or the image coverage ratio per transfer material.

Abstract: A developing unit supplies toner from a developing roller to an electrostatic latent image formed on an image carrier, and creates a visual image. A forced consumption unit causes, when a proportion of number of pixels used for forming the electrostatic latent image for a maximum image effective-width is equal to or less than a predetermined value, a forced consumption of toner by an amount corresponding to a difference between a toner amount corresponding to the number of pixels and a predetermined toner consumption amount. The forced consumption unit adds toner of an amount used in the forced consumption to an amount of toner to be supplied in a next imaging process.

Abstract: In an image forming apparatus a developing device develops an electrostatic latent image on an image carrier with a developer that contains toner to obtain a toner image, a toner-amount detecting unit detects amount of toner attached to the toner image, and a toner-density detecting unit detects a density of toner in the developer. Moreover, a process control unit corrects a toner-density target value indicative of a target value of density of toner in the developer based on the amount of toner detected by the toner-amount detecting unit and the density of toner detected by the toner-density detecting unit, and a determines execution timing of next process based on corrected toner-density target value.

Abstract: The image forming apparatus includes a developing device that holds a two-component developer to develop an image, a detecting unit that outputs a reference output value and a second output value when the two-component developer is stirred and carried at a stirring/carrying speed corresponding to a second image forming mode, a stirring/carrying member that stirs and carries the two-component developer, and a controlling unit that controls the toner concentration based on the reference output value when forming an image in a first image forming mode, and controls the toner concentration, when forming an image in the second image forming mode, a corrected output value obtained by correcting an output value in the second image forming mode with a difference value between the reference output value and the second output value.

Abstract: An image forming apparatus includes an image carrying member, an image forming mechanism, an optical sensor, and a controller. The image forming mechanism performs an image forming operation for forming a reference toner image on the image carrying member under a specific setting associated with the image forming mechanism. The optical sensor is arranged in a vicinity to the image carrying member. The controller performs an optical toner test for checking, by using the optical sensor, optical characteristics of the reference toner image formed on the image carrying member and to adjust the specific setting based on a result of the optical toner test.

Abstract: An image forming method and apparatus capable of implementing accurately and constantly an improved conversion of the amount of toner adhesion over the entire range of the amount of adhesion.