Canon Kabushiki Kaisha

Tsuyoshi Kunishi

Yuichiro Toyohara

Hiroyuki Ichikawa

Yoshihiko Suzuki

Nobuhiro Hayashi

Keizo Isemura

Satoru Kutsuwada

Keizo Takura

Yukio Watanabe

Toru Kabashima

Nobumasa Fukuzawa

Mitsuka Abe

Takeo Yamamoto

Jun Asai

Kazushige Nishiyama

Takeo Tsunemi

Keizo Ogara

A discharge wire usable in an electrification device includes a tungsten wire subjected to mirror finish processing and an oxidized layer formed by heating the surface of the tungsten wire at a temperature in the range 400 to 600&#xb0; C., wherein the film has a thickness in the range of 0.01 to 0.3 &#x3bc;m.

Discharge wire, method of manufacturing discharge wire and electrification device

An image forming apparatus includes an image bearing member; a driver for driving the image bearing member; a latent image forming device for forming an electrostatic latent image on the image bearing member; a developing device for developing the electrostatic latent image on the image bearing member with a developer; a cleaning member, contacted to the image bearing member, for cleaning a surface of the image bearing member; a vibration imparting device for vibrating the cleaning member; and a controller for causing the latent image forming means to form an electrostatic pattern for attracting the developer deposited on the cleaning member and for causing the device to move the electrostatic pattern to a contact portion where the cleaning member is contacted to the image bearing member.

Image forming apparatus with vibration-caused image defect prevention feature

A discharge wire usable in an electrification device includes a tungsten wire subjected to mirror finish processing and an oxidized layer formed by heating the surface of the tungsten wire at a temperature in the range 400 to 600&deg; C., wherein the film has a thickness in the range of 0.01 to 0.3 &mgr;m.

Method of manufacturing discharge wire

An image forming apparatus for outputting an image through an electrophotographic process in accordance with a digital image signal includes an electrophotographic photosensitive member; an optical system for applying light information to the photosensitive member; a developing device for forming a toner image on the photosensitive member; an input path for a plurality of digital image signals containing a bi-level digital image signal and a multi-level digital image signal; a controller for changing developing condition of the developing device when the image is outputted in accordance with the bi-level digital image signal, and changing an image forming condition which is different from the developing condition when an image is outputted in accordance with a multi-level digital image signal.

Image forming apparatus for outputting image in response to digital image signal

When an image is adjusted to compensate for individual differences among image forming units, there are cases where a phenomenon occurs in which a contour that is originally non-existent appears in a low-density portion, namely an area other than that where the output density characteristic is linear. In such instances image quality deteriorates markedly when importance is placed upon tonality. To solve this problem, a printer is caused to print an image diagnostic pattern, the image diagnostic pattern that has been printed is read by a reader and the linear portion of the output density characteristic of a design center value and the linear portion of the read output density characteristic are approximated by straight lines. Both of the output density characteristics are compared and image adjustment coefficients A, B are compared. The coefficients A, B thus obtained are set in a primary converter and gamma tables in a gamma converter are changed over in conformity with the values of the coefficients A, B.

Image processing apparatus and method for reproducing high quality image in low-density portion

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

The present invention provides a fixing apparatus comprising a heater generating heat by communication, a heat body to be heated by the heater, a temperature detection element for detecting an temperature of the heat body, and control means for switching warm-up control after the communication to the heater is started in accordance with a temperature change ratio of the heat body.

Fixing apparatus with power control based on temperature gradient

An image forming apparatus has an image bearing member, a charging member which contacts with the image bearing member to charge it, detecting device for detecting an electric current flowing through the charging member when a predetermined voltage is applied thereto, and a display device for displaying an information about a life of the image bearing member in conformity with the result of detection by the detecting device. The display device can display at least two different kinds of information corresponding to at least two different electric currents detected by the detecting device.

Image forming apparatus

A developing device is constructed by a developing unit for developing an electrostatic latent image on an image holding member, a developing agent containing unit for containing a developing agent which is supplied to the developing unit, an agitator, provided in the developing agent containing unit, for agitating the developing agent, a detecting sensor for detecting a residual amount of developing agent in the developing agent containing unit, and a determining device for determining the residual amount of developing agent at a plurality of levels on the basis of an output state of the detecting sensor in a predetermined time range. The determining device determines the residual amount of developing agent on the basis of a ratio of an output time of a developing agent presence state of the detecting sensor and an output time of a developing agent absence state in the predetermined time range. When a ratio at which the output time of the developing agent presence state of the detecting sensor occupies in the predetermined time range is equal to or less than a predetermined value, the determining device determines that the residual amount of developing agent is small, and when the ratio is substantially equal to 0, the determining device determines the absence of developing agent.

Developing device having a residual toner amount discrimination feature

In an image forming apparatus, and related method of forming an image, having a copy function, a printer function, and a facsimile function, when the absence of the toner is detected, a copy or a data print from a computer is inhibited but a recording of an image which was facsimile received is permitted. Thus, a situation such that the facsimile reception cannot be performed due to the absence of the toner at night or the like is prevented.

Image forming apparatus and related method of image forming

When a binary image signal or multivalued image signal is input to form an image, if the binary image signal is input, one of the line width output characteristic previously stored in memory is set and displayed. If the multivalued image signal is input, one of the density output characteristic previously stored in the memory is set and displayed. Each of the line width output characteristic and the density output characteristic can be changed by the operator. The line width output characteristic is changed by changing the development bias voltage, and the density output characteristic is changed by changing the .gamma.-table.

Image processing apparatus for inputting and processing plural types of

An image forming apparatus which varies the blending ratio by which color-seperated image signals are blended together to form a monochromatic image. The apparatus inputs a plurality of image signals which have been color-separated, and synthesizes the plurality of image signals by blending to form a monochromatic image. A density regulating mechanism regulates the density of the monochromatic image to a predetermined density level, and the apparatus varies the blending ratio of the synthesized plurality of image signals based on the predetermined density level.

Electrophotographic image forming apparatus with density regulating

An object of the present invention is to perform a well tonality reproduction according to a state of an image support body. In order to achieve the object, the present invention is featured by comprising the image support body for supporting an image which is to be formed on a medium, a signal generation means for generating an image signal representing the image, a detection means for detecting a value according to a membrane thickness of the image support body, and a conversion means for converting the image signal on the basis of the detected value according to the membrane thickness.

A fixing device includes a first heater, a second heater having a heat distribution different from that of the first heater, a heating member heated by the first and second heaters, and a temperature detecting element for detecting the temperature of the heating member. A power supply control element controls the power supply to the first heater and second heater in such a manner that the temperature detected by the temperature detecting element is maintained at a target temperature. After a fixing operation and until the temperature detected by the temperature detecting element rises from the fixing temperature to a stand-by temperature higher than the fixing temperature, the power supply element is adapted to effect power supply control different from that in the stand-by state.

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Yokohama, Japan

Tsuyoshi Kunishi