Canon Kabushiki Kaisha

Taisuke Matsuura

Kota Arimoto

Ryo Hanashi

Jun Tomine

Yasushi Takeuchi

Yusuke Ishida

Takanori Iida

Toshiyuki Yamada

Koji Arimura

Takayuki Ganko

Koto Arimoto

An image forming apparatus includes an image bearing member, a transfer belt, a secondary transfer member, a voltage source, a current detecting portion, and a controller. The controller is operable in a first mode in which when a recording material is absent in a secondary transfer portion, a current flowing through the secondary transfer member under application of a first test voltage is detected by the current detecting portion and then information on a current-voltage characteristic of the secondary transfer member is acquired, and in a second mode in which a predetermined test image is transferred from the transfer belt onto the recording material under application of second test voltages and then a test chart for adjusting a transfer voltage set during transfer is outputted. On the basis of the information, the controller changes an interval of the second test voltages applied in the operation in the second mode.

Image forming apparatus using plural test images formed with different test voltages

An image forming apparatus includes an image bearing member, an image forming portion, a transfer member, an applying portion, and an executing portion configured to execute an output operation for forming and outputting a chart formed on a recording material on which a plurality of test images are transferred by applying a plurality of voltages to the transfer member by the applying portion. The executing portion changes a change width per level of the test voltage so that the change width is a first change width in a case that a material of the recording material on which the chart is formed is a first material and so that the change width is a second change width different from the first change width in a case that the material of the recording material is a second material different from the first material.

Image forming apparatus controlling formation of test images based on recording material type

Image forming apparatus

An image forming apparatus includes a belt, an image forming unit, a first roller configured to form a transfer portion where the toner image is transferred from the belt to a recording material, a second roller disposed upstream of the first roller, a pressing member disposed upstream of the first roller and downstream of the second roller, a guide member disposed upstream of the transfer portion, and a connecting member configured to electrically connect the guide member and the pressing member to each other.

An image forming apparatus includes an image forming portion, an image bearing member, a transfer member, a voltage source, a density detecting portion, a display portion, a controller, and an operating portion. The controller is capable of executing an operation in a mode in which a test chart for adjusting a transfer voltage is outputted, and setting information on the transfer voltage set for during transfer on the basis of a detection result when the test chart is detected by the detecting portion is displayed at the display portion and is checked by user. The controller causes the display portion to display setting information on the basis of a correcting value and causes the user to check the setting information in the operation in the mode executed after the correcting value is inputted from the operating portion.

An image forming apparatus includes a transfer member which transfers a toner image formed on an image bearing member to a transfer material; a transfer bias application unit which applies bias to the transfer member; a controller which executes a mode for making a first bias applied to a first predetermined area arranged at a leading edge of a transfer material with respect to a conveying direction of the transfer material to be less than a second bias applied to a second predetermined area arranged in a central area of the transfer material; and an obtaining portion which obtains image information of an image formed in each area obtained by dividing an area corresponding to the leading edge area into plural pieces in the width direction, wherein the controller controls the first bias based on image information obtained by the obtaining portion at the time of the mode.

An image forming apparatus includes a first image bearing member, a second image bearing member, an intermediate transfer belt, a first primary transfer member, a second primary transfer member, a secondary transfer outer member, a pre-secondary transfer stretch roller, a driving roller, and an execution portion. The execution portion is configured to execute a first monochromatic mode in which a bias smaller than the primary transfer bias applied to the first primary transfer member in a case where a toner image is formed on the first image bearing member is applied to the first primary transfer member, and the primary transfer bias applied to the second primary transfer member in a case where a toner image is formed on the second image bearing member is applied to the second primary transfer member.

When ending image forming, a state is realized where charging by a charging roller is stopped (charging bias off) and also applying DC voltage at a developing device is stopped (developing bias DC off). In this state, AC voltage is applied to the developing device (developing bias AC on), thereby adhering toner to the surface of a photosensitive drum and forming interposing toner. Driving of the photosensitive drum and an intermediate transfer belt is then stopped in the state with the interposing toner interposed between the photosensitive drum and intermediate transfer belt.

Image forming apparatus to suppress excessive interposing toner

An image forming apparatus includes a photosensitive member, a charging member, a charging voltage source, an exposure device, a developing device, a developing voltage source, a transfer member, a transfer voltage source, a detecting member, a setting portion for setting, a transfer voltage applied to the transfer member on the basis of a detection result of the detecting member, and an adjusting portion for increasing a potential difference between the potential of the photosensitive member charged and the developing voltage so as to be large when an absolute value of the transfer voltage set by the setting portion is a first threshold or more and an absolute value of the current flowing at the time of application of the transfer voltage to the transfer member is a second threshold or less.

Image forming apparatus with control of transfer bias and charging bias

An image forming apparatus includes a plurality of photosensitive drums, and a controller for executing, when an absolute value of a set point of a charged potential is not higher than a predetermined threshold, an operation in a first mode in which charging bias voltages and transfer bias voltages are applied to image regions of the drums, at a preset length of time before image exposures are carried out by the exposure members and thereafter, the image exposures are carried out by the exposure members, respectively, and for executing, when the absolute value of the set point of the charged potential is higher than the predetermined threshold, an operation in a second mode in which timings of starting applications of the transfer bias voltages to the transfer members are delayed as compared with those in the first mode, respectively.

Image forming apparatus that adjusts the start timings of transfer bias voltage applications to prevent nonuniformity in printed image density

An information forming apparatus includes an execution unit configured to execute a setting mode which sets a voltage to be applied to the transfer member during an image formation operation and a correction mode which corrects the voltage set by the setting mode and a storage unit configured to store in advance a correction current difference based on the environment that is a difference between a current when a predetermined voltage is applied to the transfer member during the first period and a current when a predetermined voltage is applied to the transfer member during the second period. The execution unit corrects the voltage set by the setting mode in accordance with the correction current difference based on a detection result from the first detection member and a detection result from the second detection member in a case that the correction mode is executed during the first period.

Image forming apparatus for correcting a set voltage to be applied during an image formation operation

An image forming apparatus includes a controller executing a setting mode for setting a voltage to be applied to an image transfer member when a toner image is transferred onto a transfer medium, so that a predetermined current flows through a charging member when such an area of an image bearing drum as has carried the toner image transferred onto a transfer medium at a transfer portion then passes through a charge portion, the setting being executed on the basis of a current detected by a first detecting member when such a region of the drum as has been charged by the charging member and has been passed through the transfer portion in a state that a test voltage is applied to the transfer member then passes through the charge portion in a period in which no toner image passes through the transfer portion.

Image forming apparatus controlling voltage of transfer member

An image heating apparatus including: an image heating member for heating an image formed on a sheet at a nip portion; a temperature detector for detecting temperature of a predetermined region of the image heating member; a cooler for cooling the predetermined region; and an activating device for activating the cooler to perform a cooling operation in accordance with an output of the temperature detector, wherein the apparatus has a first mode of stopping a cooling operation in accordance with an output of the temperature detector; and a second mode of stopping the cooling operation in accordance with an end of image heating processing irrespective of the output of the temperature detecting device. The image heating apparatus is capable of suppressing unnecessary energy consumption, and of eliminating uneven glossiness due to a reduced temperature region at a boundary between a sheet passing portion and a non-sheet passing portion.

Image heating apparatus

An image heating apparatus includes a heating rotary member, which heats an image on a recording material at a nip portion, an air blowing device for blowing air toward an air blowing port to cool a predetermined area of the heating rotary member, a shutter, which opens and closes the air blowing port, and a determination device. The determination device determines an execution of an operation of the air blowing device with the shutter opened after a first job is completed, in accordance with a size of a recording material in a width direction perpendicular to a recording material transport direction in a second job for supplying a recording material, between an execution termination of the first job for continuously supplying recording materials having a size smaller than a predetermined size in the width direction, while operating the air blowing device, and a start of a recording material supply of the second job, in a case that the second job is executed subsequent to the termination of the first job.

An image heating apparatus including: an image heating member, which heats an image on a recording material in a nip portion; an air blower, which blows air toward an air blowing port to cool a predetermined area of the image heating member; and a shutter, which opens and closes the air blowing port, in which the shutter is kept at a closed position when a temperature of the predetermined area of the image heating member is equal to or lower than a predetermined temperature, whereby a temperature rise in a non-sheet passing portion can be efficiently reduced by using the small air blower without lowering the productivity when small-size recording materials are continuously passed nor reducing the lifetime of the air blower.

Growing community of inventors

Toride, Japan

Taisuke Matsuura