Konica Corporation

Konishiroku Photo Industry Co., Ltd.

Kunihisa Yoshino

Satoshi Haneda

Hisashi Shoji

Masakazu Fukuchi

Shizuo Morita

Mitsuo Motohashi

Shizuo Kayano

Yukio Okamoto

Jun Yokobori

Hiroyuki Yamamoto

Satoshi Nishida

Masahiko Itaya

Seiichiro Hiratsuka

Hiroshi Tokunaga

Akitoshi Matsubara

Hiroshi Fuma

Toshiro Fujimori

Yozo Fujii

Akihiko Tamura

Yoshiyuki Ichihara

Kazuo Yasuda

Kimio Nishizawa

Yuki Okuyama

Toshihiro Takesue

Jun-ichi Hamada

Tsugio Sugizaki

Masayuki Kamegamori

Yoshiko Matsuoka

Takahiro Tuchiya

Akira Takahashi

Michio Osada

An image forming apparatus having a first mode for image forming at a first recorded pixel density and a second mode for image forming at a second recorded pixel density that is higher than that in the first mode, includes: a selector for selecting either the first mode or the second mode; a fixing unit having a temperature detecting sensor to detect a temperature of the fixing unit; and a controller for changing a temperature condition to be set for the fixing unit in accordance with a change between the first recorded pixel density and the second recorded pixel density selected by the selector. When the first mode is changed to the second mode by the selector, the controller controls to switch the temperature condition of the fixing unit from a temperature condition H1 in the first mode to a temperature condition H2 in the second mode lower than that of the temperature condition H1, provides a predetermined second control temperature h2 between the temperature condition H1 and the temperature condition H2 to control inhibiting or allowing an image forming, and controls to inhibit the image forming when a temperature detected by the sensor is higher than the second control temperature h2, and to allow the image forming when the temperature detected by the sensor is lower than the second control temperature h2.

Image forming apparatus and control method thereof

A method for controlling an image forming apparatus which has a photoreceptor and a writing system to write a latent image on the photoreceptor with plural laser beams. The method includes the steps of: correcting positional deviations among the plural laser beams; conducting at least one of maximum density correction and gradation correction for image forming operation of the image forming apparatus by providing at least one standard density pattern on the photoreceptor with the plural laser beams; and repeating the correcting step of positional deviations among the plurality of laser beam. All of the steps are conducted when the image forming apparatus is in a warm-up state in succession to a turn-on operation thereof.

Method for controlling an image forming apparatus which uses plural

An image forming apparatus includes an image carrier on which a plurality of latent patch images are formed by exposure of different luminance, and the latent patch images are developed to form toner patch images. The apparatus further includes a gradation correction curve forming device in which a gradation correction curve is made from reflection density data of the patch toner image. The correction curve is formed, and gradation correction processing is conducted in accordance with the correction curve, so that an image forming process can be carried out. Further, when the correction curve cannot be obtained, at least one predetermined gradation curve stored in a memory in advance is selected as a substitution for the correction curve.

Image forming apparatus having image density gradation correction means

A method for forming a toner image on a photoreceptor includes charging a photoreceptor to a charged electric potential; exposing the photoreceptor so as to form a reference latent image for each of three colors with an exposure light having a reference image density; developing the three reference latent images with yellow, magenta and cyan developers each of the developers including a carrier and one of the yellow, magenta and cyan color developer so as to form a superimposed three color toner image; detecting a color balance between the superimposed three color toner images by separating reflected light from the superimposed images; and consuming at least one color developer of the yellow, magenta and cyan developers in accordance with a detection result of the color balance so that a new color balance of the superimposed three color toner images will have a desired color balance.

Color image recording apparatus with a detector to detect a superimposed

An apparatus for forming a latent image on a photoreceptor with a laser beam and for developing the latent image with a developer. A duty ratio of the laser beam is changed in accordance with the laps of using time of the developer.

Image forming apparatus provided with a laser-beam-writing means

An image forming machine, such as a printer or a copying machine for forming a toner image on a photoreceptor includes an image writer, such as a laser beam generator, for forming a latent image on the photoreceptor; a developer for developing the latent image with a developer, which includes a toner and a carrier; a controller for controlling a toner concentration of the developer so that the toner concentration is equalized; a circuit to automatically form a reference toner image on the photoreceptor; a detector for detecting a toner deposition amount of the reference toner image; and a controller circuit for decreasing a toner charge amount of the toner when the toner concentration is equalized and the toner deposition amount of the reference toner image is smaller than a predetermined value.

Electrostatic recording apparatus using variable bias developing voltage

A color image forming apparatus including a color image reader for optically scanning a document to produce blue, green, and red color separated information, a processor for processing the color separating information supplied by the reader and generating black, yellow, magenta, and cyan color information signals, a rotatable image retainer, and two latent image forming devices for forming latent images at a common region on the image retainer in accordance with the color information signals corresponding to two recording colors. The first latent image is formed by one of the latent image forming devices in synchronization with the scanning of the color image recorder to form a first latent image at a first writing position. The second latent image forming device is delayed to form the second latent image at a second writing position. The delay device compensates for the time necessary for the common region on the image retainer to travel between the first and second writing positions. The apparatus further includes a number of developers, each developer being used to develop one of the latent images, thereby forming a multicolor image composed of multiple toner images on the image retainer. Two color latent images, corresponding to two of the color information signals, are formed on the image retainer and developed by the developing means during the first rotation of the image retainer corresponding to a first optical scanning of the document, and the remaining two color latent images, corresponding to the remaining two color information signals are formed on the image retainer and developed by the developing devices during a second rotation of the image retainer corresponding to a second scanning of the document. All the toner images are then simultaneously transferred to the transfer sheet.

Color image forming apparatus

An image forming apparatus which detects deterioration of developer contained in a developing unit, and if it is the case, the toner is discharged out of the developing unit through a surface of an image carrying member. The apparatus is provided with a sensor to measure toner concentration in developer contained in the developing unit, a drive controller to control a supply amount of toner into the developing unit based on the toner concentration, a calculating unit to obtain average toner supply during a predetermined period, a detecting unit to detect the deterioration of the developer by comparing the average toner supply with a reference data stored in a memory.

Image forming apparatus having a developer deterioration detecting device

A developing device for use in an image recording apparatus, comprising: a developer stirrer which stirs toner and carrier in order to prepare the compostion of developer; a developer supplier which supplies the developer prepared by the developer stirrer; a developer holder which attracts the developer supplied by the developer supplier onto its surface, conveys the developer to the development region; a height regulator which regulates the layer thickness of the developer attracted onto the surface of the developer holder; a developer remover which removes the residual developer from the surface of the developer holder after development; a magnetic conveyor which conveys the developer removed from the developer holder to the region of the developer stirrer; and a mechanical conveyor which is placed in the region between the magnetic conveyor and the developer stirrer, which removes the developer attracted onto the surface of the magnetic conveyor, and moves the removed developer toward the region between the magnetic carrier conveyor and the developer stirrer.

Developing device

A developing apparatus for supplying a developer to a photoreceptor so that an electrostatic latent image on the photoreceptor is developed with the developer. The developing apparatus comprises a developer conveyer, having a rigid surface, for conveying the developer to a developing zone; a developer layer-thickness regulator, shaped like a bar and having a rigid surface portion of the curvature radius between 0.5 mm and 15 mm, for regulating the thickness of the developer to be conveyed to the developing zone; and a supporter for supporting the developer layer-thickness regulator.

Image forming apparatus

An image-forming apparatus of the electrophotographic type. Color images are made while also enabling formation of a sharp black image formed by utilizing a set of color toner development units, at least one of which is replaceable by a black toner development unit when black toner is required. This results in a simpler, more compact, and effective image-forming apparatus.

A color image processing apparatus including an image-reading device for reading a color image on an original to obtain first color image data, an image memory which stores the first color image data, and a factor memory which stores a predetermined correction factor. A color correction system corrects the first color image data with the correction factor. An image-producing apparatus produces a color copy image on the basis of the corrected first color image data, where the image-reading device reads the color copy image to obtain second color image data. The image-processing apparatus further includes a processing member which performs a comparison between the first color image data stored and changes the correction factor on the basis of the comparison.

Color correction device for a color image forming apparatus

The object of the present invention is to provide an image forming apparatus capable of enabling high-speed continuous copy of an same single-color image, wherein the apparatus is incorporated with a shift register between an image reader and a laser beam generated for performing imagewise exposure onto a photoreceptor. The shift register has a circulation circuit connecting between an output and an input side thereof. After an image data corresponding to a sheet of original document is inputted into the shift register, the circulation circuit is actuated and circulates the image data, thereby repeatedly outputting the image data to the laser beam generator by the number of required times.

Multi-color image forming apparatus

An image forming apparatus wherein a toner image obtained by developing a first electrostatic latent image with a first color dry toner by a first developing device and a toner image obtained by developing a second electrostatic latent image with second color dry toner which is different in color from said first color dry toner by a second developing means are superposed on an image retainer, and wherein toner feeding speeds at which the first and second developing devices develop the first and second electrostatic latent images, resepctively, are different from each other and an attached amount of the second color toner is smaller than that of the first color toner.

An image forming method wherein a latent image is formed by subjecting an image retainer having a photoconductive layer to a image exposure, a toner image is formed by developing the latent image with a toner, each the step of forming the latent image and the step of forming the toner image are repeated at least one time, and a plurality of toner images formed on the image retainer to a transfer material. At least one of the toner images is formed with a toner which has a spectral transmissivity as to substantially absorb a visible light but transmit a light having a wavelength of 750 nm or more. The latent image is formed by subjecting the image retainer bearing the toner image to an image exposure with a light containing a wavelength component of 750 nm or more.

Growing community of inventors

Hachioji, Japan

Kunihisa Yoshino