Canon Kabushiki Kaisha

Masahide Hirai

Tatsuya Nakamura

Akira Kato

Mahito Yoshioka

Munehito Kurata

Kazuhiro Funatani

Yoshiro Saito

Hiroyuki Seki

Satoru Izawa

Tatsuya Kinukawa

Tomoaki Nakai

Yasutaka Yagi

Takashi Shibuya

Kimio Nakahata

Takao Kume

Shinji Hashiguchi

Hiromichi Yamada

Katsuhiko Nishimura

Masuo Yamazaki

Yasuo Yoda

Masami Takeda

Yasumasa Otsuka

Tohru Kosaka

Tohru Saitou

Ken Nakagawa

Hiroshi Kataoka

Tomoo Akizuki

Aoji Isono

Michio Uchida

Ken Murooka

Daizo Fukuzawa

Shun-ichi Ebihara

Hisashi Nakahara

Takashi Soya

Akihiro Fujimoto

Akira Hayakawa

Yuuji Takayama

Masaki Hirose

Kuniaki Kasuga

Kimitaka Ichinose

Toshikazu Tsuchiya

Hikaru Uchidate

Masao Umezawa

Noriaki Egawa

Shizuma Nishimura

Yoji Tomoyuki

Hitoshi Furukawa

Kentaro Yamashita

Hisahiro Saito

Ryosuke Hamamoto

An image forming apparatus includes a replaceable roller member, an applying unit that applies voltage to the roller member, a current detecting unit that detects a current flowing in the roller member to which the voltage is applied, and a controlling unit. The controlling unit calculates a value of a slope of a current-voltage characteristic of the roller member on the basis of a first current detected when a first voltage is applied to the roller member and a second current that is detected when a second voltage is applied, and determines whether or not the roller member has been replaced on the basis of an amount of change from a value of a first slope calculated at a first timing and a value of a second slope calculated at a second timing later than the first timing.

Image forming apparatus configured to determine whether or not a roller member has been replaced

A diagnostic system may comprise an image forming apparatus that forms a diagnostic image on a sheet and an image capturing apparatus that captures an image of the sheet on which the diagnostic image is formed and which has been discharged from the image forming apparatus, and outputs the image captured as a sheet image. The image capturing apparatus may make a diagnosis for a component of the image forming apparatus based on a position of an image deficiency in the sheet image, and output a diagnosis result for the component of the image forming apparatus.

Diagnostic system for diagnosing image forming apparatus using image formed by image forming apparatus

An image forming apparatus includes a detection unit configured to obtain information with regard to the life of a secondary transfer member based on the variation in an electric resistance value of a secondary transfer portion, wherein the detection unit performs a process of reducing the effect of variation in the electric resistance value of an intermediate transfer member contained in the variation in the electric resistance value of the secondary transfer portion, based on a detection result of information with regard to the electric resistance value of the secondary transfer portion by a second detection unit, and on a detection result of information with regard to an electric resistance value of a primary transfer portion by a first detection unit, and obtains the information with regard to the life of the secondary transfer member.

Image forming apparatus that obtains lifetime of secondary transfer member

An image forming apparatus includes an image forming unit, an acquisition unit, a fixing unit including a heating member and a pressure member forming a nip, a temperature detecting unit, and a control unit. In a case where a toner density of a toner image on a k-th recording material of a plurality of recording materials is less than the toner density of the toner image on a (k-1)-th recording material of the plurality of recording materials, k being an integer greater than or equal to two, the control unit sets a fixing temperature of the k-th recording material to a temperature which is greater than a predetermined temperature predetermined based on image information of the toner image to be formed on the k-th recording material.

Image forming apparatus and image forming method

An image forming apparatus for forming an image on a recording material by a plurality of color materials, the apparatus includes: a determination unit configured to determine, based on converted data that are converted from image data corresponding to each image formed by the plurality of color materials, values each relating to an area of a respective color material caused to adhere to a recording material; and a detection unit configured to detect, based on the values each relating to the area of the respective color material that the determination unit determines, an overlapping of color materials.

Image forming apparatus that detects overlap of color material, image processing apparatus and image processing method

The image forming apparatus includes an image forming unit, a fixing unit having a heating member, a temperature detector, an acquisition unit, and a controller. When image formation is consecutively performed, and the acquisition unit acquires a first density, which is the density information of the image formed on a k-th recording material, and a second, higher density, which is the density information of the image formed on an l-th recording material, while the image is being fixed on the k-th recording material, the controller controls the power so that the detection temperature becomes a temperature higher than a fixing temperature according to the first density, and lower than a fixing temperature according to the second density. While the image is being fixed on the l-th recording material, the controller controls the power so that the detection temperature becomes the fixing temperature according to the second density.

A fixing device fixes an image on a sheet, and includes a rotatable member having an electroconductive layer; a helical coil provided inside the rotatable member and having a helix axis extending in a generatrix direction of the rotatable member; a magnetic member provided inside a helical configuration portion formed by the coil, the magnetic member not forming a loop outside the rotatable member; and a controller for controlling electric power supplied to the coil. The electroconductive layer generates heat by electromagnetic induction caused by the magnetic flux produced by an alternating current through the coil to fix the image on the sheet by the heat from the rotatable member. The controller limits the maximum electric power supplied to the coil, in accordance with the temperature of the magnetic member.

Fixing device and image forming apparatus

A fixing device includes: a rotatable member including an electroconductive layer; a helical coil having a helical axis direction along a generatrix direction of the rotatable member; a magnetic member not forming a loop outside the electroconductive layer; a frequency setting portion for setting a frequency of an AC current caused to flow through the coil; and a temperature detecting portion for detecting a temperature of the rotatable member, including a first temperature detecting member and a second temperature detecting member. The electroconductive layer generates heat through electromagnetic induction heating by magnetic flux resulting from the AC current, and an image is fixed on a recording material by heat of the rotatable member. The frequency setting portion sets the frequency depending on a value of a difference between a detection temperature of the first temperature detecting member and a detection temperature of the second temperature detecting member.

Heat-fixing device

The image forming apparatus includes an image processing section that converts image data into pixel data, an image forming section that forms a toner image based on the pixel data, and a fixing section that fixes the toner image to the recording material by heating the recording material with the toner image formed thereon while conveying the recording material through a nip portion. The image processing section divides the pixel data corresponding to one recording material into a plurality of areas each formed of a predetermined number of pixels and acquires density information on some of the pixels within each of the areas as representative values. The fixing section carries out a process of fixing the toner image for which the density information has been acquired, under a fixing condition according to a maximum value of the representative values.

In an image forming apparatus, a control unit is capable of carrying out a cleaning mode with a first step of allowing an image forming unit to form, on an image bearing member, a cleaning toner image with a length according to a length of a feeding member or conveying member in a direction orthogonal to a conveyance direction of the recording material, a second step of moving the cleaning toner image from the image bearing member to a transfer member, and a third step of moving the cleaning toner image from the transfer member to the image bearing member.

Image forming apparatus

There is provided an image forming apparatus which shortens the time taken for circumference detection and measures the circumference at high precision without obstructing downsizing of the apparatus. To accomplish this, the image forming apparatus detects, at an arbitrary timing, the physical pattern of the image-formed surface of a rotation member that changes over time. In the second round, the image forming apparatus detects the second pattern at a timing a predetermined time after the arbitrary timing. By using the detected patterns, the image forming apparatus obtains information associated with the circumference of the rotation member.

Image forming apparatus and control method thereof

There is provided an image forming apparatus including a rotation member used for image forming and a detector for detecting light from the rotation member. First waveform data of an image-formed surface used to form an image on the rotation member is acquired by the detector. Second waveform data of the image-formed surface used to form an image on the rotation member is acquired. The second waveform data includes at least part of a detected section of the first waveform data. Information on the actual circumference of the rotation member is calculated based on matching between the acquired first and second waveform data. The acquired first waveform data and second waveform data are compared to determine whether or not to use the calculated information on the circumference. When it is determined not to use the calculated information on the circumference, information on the circumference of the rotation member is recalculated.

Image forming apparatus including a rotation member circumference calculator and control method thereof

An image forming apparatus includes a transfer roller that can be separated from an intermediate transfer belt. When an operational mode is switched from a multicolor mode to a mono-color mode, the image forming apparatus changes a rotational speed of the intermediate transfer belt to a level slower than a rotational speed of the intermediate transfer belt to be set in the multicolor mode to transfer a toner image to the intermediate transfer belt, then separates a first transfer member from the intermediate transfer belt, and after the first transfer member is separated from the intermediate transfer belt, the image forming apparatus increases the rotational speed of the intermediate transfer belt to a rotational speed to be set in the mono-color mode to transfer the toner image to the intermediate transfer belt.

Image forming apparatus that includes a transfer member that can be separated from an inner circumferential surface of a transfer belt when belt is rotating

An image forming apparatus which predicts VL fluctuates of a photosensitive drum, taking a rotation speed of the photosensitive drum during image formation into consideration, and controls the image formation based on the prediction, for always obtaining an image of a stable density. The image forming apparatus performs appropriate image formation control by controlling image forming conditions based on a photosensitive member rotation time, a photosensitive member stop time, a temperature of the environment, an absolute humidity of the environment, and the rotation speed of the photosensitive member.

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Numazu, Japan

Masahide Hirai