Abstract: An electrophotographic image formation device comprises an image transfer unit (including an image transfer member) attached to a main body in a detachable manner, a density detecting unit including a detector unit and thereby detecting density of a developing agent transferred to the image transfer member, a protective cover which protects the density detecting unit not detecting the density by covering the detector unit, first and second reflecting parts (differing in reflectivity) formed in a part of the protective cover facing the detector unit, and a shifting unit which places the protective cover at a first position (with the first reflecting part facing the detector unit) when the image transfer unit has been attached to the main body while placing the protective cover at a second position (with the second reflecting part facing the detector unit) when the image transfer unit has not been attached to the main body.

Abstract: An image forming apparatus includes a removable body that is removably set in a main body of the image forming apparatus, and an engaging mechanism that causes the removable body and the main body to engage with each other when the removable body is lifted by a user.

Abstract: A communication unit has a first conveyance part connected to a toner cartridge and provided with a feed port for a toner from the toner cartridge, and a second conveyance part connected to a developing device and provided with a replenishment port for a toner to the developing device. In a state locked by the lock mechanism, the first conveyance part and the second conveyance part are connected to each other, and the feed port of the first conveyance part and the replenishment port of the second conveyance part are opened, allowing for a toner replenishment. In a lock-released state, the feed port of the first conveyance part and the replenishment port of the second conveyance part are closed by a circular arc-shaped shutter member and a rotary shutter member, allowing the first conveyance part and the second conveyance part to be separable from each other.

Abstract: A magnetic field generating member with high stiffness and small size, an image development device, a process cartridge and an image forming apparatus including the magnetic field generating member as well as a manufacturing method of the magnetic field generating member are provided where the magnetic field generating member includes a main body, a groove provided in the main body, an interposition member configured to be fitted in the groove of the main body and including a concave portion and a magnetic member as a long magnetic compact fixed into the concave portion of the interposition member.

Abstract: An image forming apparatus include an image bearing member, a developing container receiving a developer, a developer carrying member for carrying and conveying the developer, a developer feed member for supplying the developer to the developer carrying member, a detection device for detecting an amount of developer in the developing container by detecting an electrostatic capacitance between the developer carrying member and the developer feed member, and a control device for changing a rotational speed of the developer feed member into a plurality of speeds corresponding to the plurality of image forming speeds. The control unit controls the rotational speed of the developer feed member prior to the execution of a detection operation of the detection device so as to be faster than the slowest speed of said plurality of speeds.

Abstract: An image forming apparatus includes a main frame having a first driving force transmitting part, and a first electrode to supply power, a developing cartridge mounted to the main frame, and having a second driving force transmitting part engaged to the first driving force transmitting part to receive a driving force, and a second electrode electrically connected with the first electrode, and a pressing member disposed to the main frame to regulate a widthwise direction movement of the developing cartridge mounted to the main frame to guide an engagement between the first and second driving force transmitting parts, and an electrical connection between the first and second electrodes.

Abstract: A cleaning member is elastically forced on a bearing surface, for cleaning off particles from the bearing surface by a movement of the bearing surface relative to the cleaning member. In particular, the cleaning member has first and second portions capable of forming first and second ramps having first and second acute internal angles on upstream and downstream sides of a contact region with respect to a moving direction of the bearing surface, respectively, the contact region being defined between the cleaning member and the bearing surface when the cleaning member is forced on the bearing surface.

Abstract: An image-forming apparatus that is provided with an intermediate transfer member that has a hard releasing layer formed on the surface thereof, supports a toner image primary-transferred onto the hard releasing layer from a latent-image supporting member, and secondary-transfers the supported toner image onto an image-receiving medium, and a cleaning blade that is arranged in contact with the intermediate transfer member, and removes residual toner from the hard releasing layer of the intermediate transfer member, wherein the cleaning blade has an impact resilience in the range from 20 to 50% at 20° C.

Abstract: A powder conveying device and an image forming apparatus having the same are disclosed. The powder conveying device to convey powder such as toner, includes a conveying plate to carry powder thereon, a vibration generating device to vibrate the conveying plate, and a plurality of conveying protrusions provided on a surface of the conveying plate to convey the powder loaded on the conveying plate. Each of the conveying protrusions has an incline of an upstream side and an incline of a downstream side on a powder conveying path. The incline of the upstream side is smaller than the incline of the downstream side. The powder conveying device can realized with smaller size and/or with lower cost.

Abstract: A developing unit and image formation device in which a developer carrier is reliably pressed towards and separated from an image carrier is described. A separation and pressing mechanism is provided for separating and pressing the developer carriers of developing cartridges installed in a drum unit onto image carriers. This separation and pressing mechanism has a pair of direct cam members. Each direct cam member has a release action portion that engages with the releasing projection of a developing cartridge when the developer carrier is to be separated from the image carrier. Each direct cam member may also have a pressing action portion that engages with the pressing projection of the developing cartridges when the developer carrier is to be pressed onto the image carrier.

Abstract: A toner consumption-calculating apparatus includes a printed portion area-detecting unit that detects an area of a printed portion of image data of a latent image that is formed on a latent image-bearing member; a latent image portion area-detecting unit that detects an area of a latent image portion on the latent image-bearing member; and a latent image portion toner consumption-calculating unit that calculates latent image portion toner consumption that indicates toner amount that is consumed due to adhering on the latent image portion. The latent image portion toner consumption-calculating unit uses a detection result of the latent image portion area-detecting unit and a detection result of the printed portion area-detecting unit to calculate the latent image portion toner consumption.

Abstract: An image forming apparatus includes an image carrier to carry a toner image and a fixing device to fix the toner image transferred from the image carrier onto a recording medium by applying at least heat to at least one of the toner image and the recording medium. Such a fixing device includes: a magnetic flux generator to generate a magnetic flux; and a heat generating member disposed at least partially in the magnetic flux. The heat generating member includes a heat generating layer to generate heat via eddy currents therein induced by the magnetic flux, magnitudes of the eddy currents varying according to positions thereof in a width direction of the heat generating layer. Included within the heat generating layer is a magnetic layer having a Curie point in a range, e.g., from about 100 degrees centigrade to about 300 degrees centigrade.

Abstract: In an embodiment of the invention, it is detected whether an auxiliary power source device is mounted in an apparatus main body or not. When the auxiliary power source device is mounted in the image forming apparatus, after a specified time has passed in a printable state, power supply to a first heat roller to heat a heat roller is shifted to a sleep mode. When the auxiliary power source device is not mounted in the image forming apparatus, after a specified time has passed in the printable state, a shift is made to a preheat mode in which the heat roller is kept at a preheat temperature, and a specified time has further passed, a shift is made to a sleep mode.

Abstract: An image forming apparatus includes image bearing member having a movable surface; charging means for charging the surface of the image bearing member; image exposure means for exposing the surface of the image bearing member charged by the charging means to light in accordance with image information, thus forming an electrostatic image; developing means for developing the electrostatic image formed on the image bearing member into a developed image; surface potential detecting means for detecting a potential of the surface of the image bearing member; discharging means for discharging the surface of the image bearing member; changing means for changing an image forming condition, wherein an area of the image bearing member passes the discharging means under different operating conditions of the discharging means, and the area is charged by the charging means, the changing means changes the image forming condition on the basis of a result of detection, by the surface potential detecting means, of surface pote

Abstract: An image forming apparatus may include a casing, and a plurality of image carriers parallelly arranged along one direction in the casing and formed with an electrostatic latent image. The apparatus can further include a plurality of developing agent carriers opposed to the image carriers, for visualizing the electrostatic latent image by feeding a developing agent to the image carriers, and a plurality of developing agent cartridges, parallelly arranged in the one direction to be opposed to the developing agent carriers in the longitudinal direction of the developing agent carriers, and configured to be together attachable/detachable to/from the casing along the one direction, for accommodating the developing agent fed to the developing agent carriers.

Abstract: An image forming apparatus includes an image bearing member, a toner image forming member, an intermediary transfer member for forming a primary transfer portion, and a primary transfer member supplied with a transfer voltage. The apparatus also has a voltage source for supplying, to the primary transfer member, a transfer voltage and a voltage of a polarity opposite to the transfer voltage, an image bearing member cleaning apparatus for removing toner from the image bearing member, a secondary transferring member, and an intermediary transfer member cleaning apparatus for electrostatically removing toner from the intermediary transfer member. The apparatus further has a voltage source control apparatus for controlling the voltage source so as to apply, to the primary transfer member, a voltage having an absolute value larger than a discharge threshold and having the polarity opposite to the transfer voltage, when a non-recording toner pattern passes through the primary transfer portion.

Abstract: An image forming apparatus includes a placement tray, an image forming unit, a drive unit, a control board, a power supply substrate, a high-voltage board, and low-voltage power supply harnesses. The placement tray holds a recording sheet thereon. The image forming unit forms an image on the recording sheet. The drive unit supplies driving force to the image forming unit. The control board controls the drive unit. The power supply substrate supplies electric power to the control board. The high-voltage board is disposed in one side of the placement tray. In the high-voltage board, voltage is generated higher than voltage in the power supply substrate. The low-voltage power supply harnesses are disposed in another side of the placement tray so as to supply electric power from the power supply substrate to the control board.

Abstract: A developing unit of an image forming apparatus includes a developer cartridge detachably mounted on the developing unit, a developing case in which a developing member and a first supply member are provided, a developer supply passage to supply a developer stored in the developer cartridge to the developing case, and a developer supplement unit mounted in a portion connecting the developing case and the developer supply passage, to agitate the developer supplied through the developer supply passage and to supply the agitated developer to the developing case.

Abstract: The present invention provides an image forming apparatus comprising an image forming unit configured to form an image on an image carrier, a transfer unit configured to transfer the image formed on the image carrier onto a transfer medium, a voltage applying unit configured to apply a voltage to the transfer unit, a current detection unit configured to detect a current that flows through the transfer unit when the voltage applying unit applies the voltage, and a control unit configured to control the voltage applying unit based on a detection result of the current detection unit.

Abstract: A color registration method in a color image forming apparatus including a plurality of drum-type photoconductors for driving some or all of the photoconductors having the same diameter to match pitch fluctuations which correspond to a rotational cycle of the photoconductors, the method including: a first measurement step for forming a first registration image for each color and measuring formation positions of a plurality of predetermined portions in each registration image; a second measurement step for forming a second registration image for each color and measuring formation positions of a plurality of predetermined portions in each registration image; a calculation step for calculating a periodic fluctuation component being contained in the images in different colors and corresponding to the rotational cycle of the photoconductors so as to obtain phases thereof; and a step for adjusting a rotational phase of the photoconductors in order for the obtained phases matching to each other, wherein the interval