Abstract: image which develops the image density control electrostatic image formed on the image bearing member by the developing apparatus, wherein, in case the detection result by an environment detection portion is changed by a predetermined value or the replenishment developer is renewed, the process advances to a mode of performing the image density control, while performing the replenishing operation by developer replenishing means not depending on the result detected by the image density detection portion but based on the detection result of the developer density detecting means.

Abstract: The present invention concerns controlling a potential used to form an electrostatic image for image formation. According to the invention, an electrostatic latent image is formed on an image bearing member using, for example, a potential stored in a memory. The potential of the latent image is detected, and if the potential is not within a specified range, the potential is controlled (i.e., changed) to form another latent image with the changed potential. The latent image is then developed and the density of the developed image detected. In one embodiment, the amount of developer to be replenished is then controlled based upon the detected density and a target potential value, where the target potential value is determined and set based on the detected density and the potential used in the potential controlling step.

Abstract: An image forming apparatus comprises an image bearing member, developing portion for developing by developer an electrostatic latent image formed on the image bearing member, potential detection portion for detecting the potential of the electrostatic latent image on the image bearing member for detection use, potential control portion for controlling the electrostatic latent image for detection use in accordance with the output of the potential detection portion, and density detection portion for detecting the density of a developer image for detection use. For this image forming apparatus, the density detection portion detects the density of a developer image for detection use obtained by developing by the developing portion an electrostatic latent image for detection use which is potentially controlled by the potential control portion.

Abstract: A developing apparatus for developing an electrostatic image formed on an image bearing member includes a first developer bearing member for bearing magnetic developer to transport it to a first developing portion, a first magnetic field generator stationarily provided in the first developer bearing member, a second developer bearing member for bearing magnetic developer to transport it to a second developing portion, and a second magnetic field generator stationarily provided in the second developer bearing member. The first developer bearing member and the second developer bearing member supply the magnetic developer to the electrostatic image on the image bearing member in the mentioned order. In addition a peak value of a normal line direction component of a magnetic force generated in the vicinity of the second developing portion is larger than a peak value of a normal line direction component of a magnetic force generated in the vicinity of the first developing portion.

Abstract: A developing apparatus includes a developer container containing a magnetic developer comprising a toner and a wax contained in the toner, first and second developer carrying member, rotatably provided in the developer container, for carrying the magnetic developer, a regulation member for regulating a thickness of a layer of the magnetic developer carried on the first developer carrying member, and magnetic field generation means for generating a magnetic field for transferring the magnetic developer from the first developer carrying member to the second developer carrying member. A common electrostatic latent image formed on an image bearing member is developed with the developer carried on the first developer carrying member and the developer carried on the developer carrying member in this order.

Abstract: A developing apparatus includes a developer container containing a magnetic developer comprising a toner and a wax contained in the toner, first and second developer carrying member, rotatably provided in the developer container, for carrying the magnetic developer, a regulation member for regulating a thickness of a layer of the magnetic developer carried on the first developer carrying member, and magnetic field generation means for generating a magnetic field for transferring the magnetic developer from the first developer carrying member to the second developer carrying member. A common electrostatic latent image formed on an image bearing member is developed with the developer carried on the first developer carrying member and the developer carried on the developer carrying member in this order.

Abstract: A developing apparatus includes a developing container for containing a developer comprising toner and a carrier, said developing container is partitioned into a first chamber and a second chamber constituting a circulation path of the developer; a first developing rotatable member, provided in said first chamber, for developing an electrostatic image formed on the image bearing member with the developer in said first chamber; a regulating member for regulating a layer thickness of the developer on said first developing rotatable member; first magnetic pole and second magnetic pole, disposed in said first developing rotatable member in order named in a rotational direction of said first developing rotatable member, said first magnetic pole and second magnetic pole being defective to form a repelling magnetic field; a second developing rotatable member, disposed in said second chamber, for developing the the electrostatic image formed on the image bearing member with the developer magnetically received from sa

Abstract: The present invention concerns controlling a potential used to form an electrostatic image for image formation. According to the invention, an electrostatic latent image is formed on an image bearing member using, for example, a potential stored in a memory. The potential of the latent image is detected, and if the potential is not within a specified range, the potential is controlled (i.e., changed) to form another latent image with the changed potential. The latent image is then developed and the density of the developed image detected. In one embodiment, the amount of developer to be replenished is then controlled based upon the detected density and a target potential value, where the target potential value is determined and set based on the detected density and the potential used in the potential controlling step.

Abstract: A developing apparatus has a developer carrying body provided to face an image bearing body. The developer carrying body carries and conveys a developer having toner and carrier to a developing region. A bias applying device applies a developing bias to the developer carrying body, wherein the bias applying device applies to the developer carrying body the developing bias having periodically a voltage portion having alternately a first voltage to generate an electric field to direct toner from the developer carrying body to the image bearing body and a second voltage to generate an electric field to direct the toner from the image bearing body to the developer carrying body and a pause portion to pause applying the alternate voltage, wherein T1 and T2 have a relationship of T1>T2, where T1 is as an applying time period of the first voltage and T2 is an applying time period of the second voltage.

Abstract: A developer density controlling apparatus includes image density detecting device for detecting a target density on the basis of a detected image and, if a difference between a toner density detected by a developer density detecting device and the target density is equal to or greater than a predetermined value, the image density detecting device does not correct the target density.

Abstract: An image forming apparatus comprises an image bearing member, developing portion for developing by developer an electrostatic latent image formed on the image bearing member, potential detection portion for detecting the potential of the electrostatic latent image on the image bearing member for detection use, potential control portion for controlling the electrostatic latent image for detection use in accordance with the output of the potential detection portion, and density detection portion for detecting the density of a developer image for detection use. For this image forming apparatus, the density detection portion detects the density of a developer image for detection use obtained by developing by the developing portion an electrostatic latent image for detection use which is potentially controlled by the potential control portion.

Abstract: The present invention relates to a developer density controlling apparatus in which image density detecting means a target density on the basis of a detected image corrects and, if difference between a toner density detected by developer density detecting means and the target density is equal to or greater than a predetermined value, the image density detecting means do not correct the target density.

Abstract: An image forming apparatus is capable of toner replenishment based on density reference toner image and toner replenishment based on ration of toner to carrier. The apparatus is provided with an image carrier, a developing unit for developing the electrostatic image on the image carrier with developer of toner and carrier, replenishing unit for replenishing the toner to the developing unit, image density sensing unit for sensing a density of the developed toner image, ration sensing unit for sensing a ratio of the toner to the carrier in the developing unit, and selecting unit for selecting one of first toner replenishment in which an amount of toner based on a sensing output from the image density sensing unit is replenished, and second toner replenishment in which an amount of toner based on a sensing output from the ratio sensing unit is replenished.