Canon Kabushiki Kaisha

Takeo Yamamoto

Fumihiro Arahira

Takao Honda

Daisaku Kamiya

Tsuyoshi Watanabe

Naohisa Nagata

Shigeo Hata

Mitsuhiro Ota

Satoshi Tomiki

Makoto Yanagida

Tadashi Ishikawa

Hiroyuki Suzuki

Yasunori Chigono

Harumi Ishiyama

Masahiro Inoue

Koji Masuda

Kensaku Kusaka

Seiji Mashimo

Masahiro Itoh

Ryo Inoue

Tadashi Furuya

Tsuyoshi Kunishi

Kenichiro Waki

Isamu Sato

Tetsuya Kuribayashi

Takahiro Noguchi

Keizo Takura

Masanori Muramatsu

Kazukiyo Akashi

Hisaaki Senba

Osamu Sugino

Hiroyuki Osada

It is determined whether a low density area in which pixels having density less than a predetermined density exist in succession is included in an image signal or not, and if the low density area exists, an image is formed by irradiating the laser light in a first condition for a pixel to be interested in each pixel area within the low density area and irradiating the laser light in a second condition being different from the first condition for other pixels in the pixel area. In this way, it is possible to improve reproducibility of a highlight area in a high resolution image and improve reproducibility of characters and line images or the like.

Image forming apparatus and control method thereof

An image forming apparatus includes an image forming part for forming a toner image on an image bearing body based on an image signal, and a density detection part for detecting a density of the toner image on the image bearing body, such that it is determined whether a normal image formed by the image forming part has a density detection area which should be detected, and if it is determined that the density detection area is present, image forming conditions are controlled based on a detection result of the density detection area.

Image forming apparatus with a toner image density feature and related method

An image forming apparatus that can realize an image having adequate image quality, density and color, without provoking excessive consumption of a developer and reduction in productivity. Image formation is performed by forming a latent image on an image carrier based on image information, then developing and transferring the latent image. An image for adjustment on a portion is formed other than a portion on which the latent image is formed on the image carrier. The density of the image for adjustment is detected. Image density is adjusted based on the density of the detected image for adjustment. Image formation control is executed whereby density is adjusted when an image is formed. A printing rate that indicates the percentage of the image formation to a sheet used for image formation is calculated. When the printing rate is determined to be within a set range, the image formation control is executed at a set frequency. On the other hand, when the printing rate is determined to be outside the set range, the set frequency is changed and the image formation control is executed.

Image formation control based on printing rate

An image forming system includes an image forming unit which forms an image as a toner image on a printing medium, a first fixing unit which fixes, on the printing medium, the toner image formed by the image forming unit, a second fixing unit arranged at a position different from the first fixing unit and used when a larger amount of heat is necessary for fixing the toner image on the printing medium, and a changing unit which changes the sequence of image formation by the image forming unit when the second fixing unit is used during image formation.

Image forming system and control method that change sequence of image formation based on fixation method

An image forming apparatus includes an image bearing member, an electrifying member for electrifying the image bearing member; an image forming member for forming an image on the image bearing member electrified by the electrifying member; a conveying member for making a recording material, which has been conveyed from a recording material receiving portion held in waiting and waiting then conveying the image on the image bearing member to a transfer portion for transferring the image onto the recording material; and a control member controls a start timing of electrification by the electrifying member in accordance with a start timing of a conveyance of the recording material by the conveying member.

Image forming apparatus with variable waiting time conveyance feature

An image forming apparatus with an image bearing member and a charging member for contactably charging the image bearing member. The charging member is provided within an exchangeable unit. An electric power containing an AC component is applied to the charging member, and adjustments are made to the magnitude of the AC component. When the exchangeable unit is exchanged, the magnitude of the AC component is returned to an initial value thereof, so as to extend the life of the image bearing member in situations where the exchangeable unit is exchanged and the AC component might otherwise have a magnitude inappropriate for the new unit.

Image forming apparatus capable of adjusting AC applied to charging member

An image forming apparatus has an image forming device and a changing device, and the image forming device is capable of forming an image by the use of a recording device, and forming an image without the use of the recording device, and when an image is to be formed without the use of the recording device, the changing device converts the image signal and changes the density of the image, and when an image is to be formed by the use of the recording device, the changing device does not convert the image signal, but controls the image forming condition of the image forming device and changes the density of the image when the density of the image is to be changed in the course of the formation of the image.

Image forming apparatus with density adjustment

An image forming apparatus includes a photosensitive body, a charging member for charging the photosensitive body, voltage applicator for applying a voltage including an AC component to the charging member, exposing device for image exposing on the photosensitive body charged by the charging member to form an electrostatic image, and developer for developing the electrostatic image, wherein the image forming apparatus can select from a first mode having low tone reproductivity and a second mode having tone reproductivity higher than that of the first mode, and wherein, when the second mode is selected, the voltage applicator applies a voltage having a frequency of the AC component higher than that when the first mode is selected.

Image forming apparatus having a charging member with plural charging

An image heating apparatus includes a heater which heats an image on a recording material, which extends in a direction perpendicular to a moving direction of the recording material; a first temperature detecting member for detecting the temperature of the heater; power controlling device for controlling the power supplied to the heater, so that the temperature detected by the temperature detecting member remains constant; a second temperature detecting member which is positioned at a location apart, in the longitudinal direction of the heater, from where the first temperature detecting member is positioned; and an interrupting device for interrupting the imaging heating process in accordance with the temperature detected by the second temperature detecting member.

Image heating apparatus with multiple temperature detecting members

An image forming apparatus includes image bearing member for bearing a toner image; charging member contactable to the image bearing member to electrically charge the image bearing member; wherein .delta.V=.vertline.Vdc-Vs.vertline. is different between a first area of the image bearing member which is going to be image area and second area of the image bearing member which is going to be non-image area, where Vdc is a DC component of a voltage applied to the charging member, and Vs is is a potential of the image bearing member charged by the charging member.

Image forming apparatus

A charging device includes a charging member for charging a movable member to be charged; the charging member including a carrying member for carrying a magnetic particle layer contactable to the member to be charged, the carrying member being adapted to be supplied with a voltage; wherein a direction of a magnetic force acting on magnetic particles in the magnetic particle layer at a downstream end position with respect to a movement direction of the member to be charged at a portion where the member to be charged and the magnetic particle layer are contacted, is opposite from the member to be charged with respect to a tangent line of the member to be charged at the end position.

Magnetic charging brush having particular magnetic fields

An image forming apparatus includes a movable image bearing member; an image forming device for forming a toner image on the image bearing member; a charging member for charging the image bearing member in a charging station; and an electrical power source for supplying power to the charging member. A detector detects the voltage-current characteristic between the charging member and the image bearing member; and a controller controls the output of the electrical power source, in accordance with an output of the detector, when a surface area portion of the image bearing member, where the toner image is not going to be formed as the image bearing member rotates, is in the charging station.

Image forming apparatus including control means for controlling an

A charging device includes a movable member to be charged; a charging member contactable to the member to be charged to electrically charge the member to be charged; a discharging device, disposed upstream of a contact portion between the charging member and the member to be charged with respect to a movement direction of the member to be charged, for electrically discharging the member to be charged at a portion adjacent to the contact portion.

Charging member and image forming apparatus having contact charging

An image forming apparatus includes a movable image bearing member, having a photosensitive layer; an image forming device for forming an image on the image bearing member: a charging member for charging the image bearing member; and a light radiating device for radiating light on the image bearing member; a detector for detecting a datum rotating to a thickness of the photosensitive layer on the basis of the voltage-current characteristic between the charging member and image bearing member; and a controller for controlling the amount of light radiated from the light radiating device to be increased with decrease in the thickness of the photosensitive layer, in response to the detector.

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Abiko, Japan

Takeo Yamamoto