Sharp Kabushiki Kaisha Corporation

Nippon Telegraph and Telephone Public Corporation

Sharp Kabuhsiki Kaisha

Yoichi Shimazawa

Kazuyuki Ohnishi

Hideo Matsuda

Syoichiro Yoshiura

Yasutaka Maeda

Osamu Fujimoto

Masato Tokishige

Tokiyuki Okano

Kiyoshi Inamoto

Kazunori Sohda

Yasuhiro Takai

Taisuke Kamimura

Hidekazu Sakagami

Kazumi Irie

Toshiaki Kawamoto

Masahiko Aiba

Shunju Anzai

Hideyuki Nishimura

Hidetomo Nishiyama

Toshiaki Tabuchi

Shinitiro Hiraoka

Hisashi Minami

Yoshie Iwakura

Hitoshi Suzuki

Yoichi Yamamoto

Katsuhiro Nagayama

Ayumu Oda

Akira Tamagaki

Yuji Sumitomo

Fumio Togawa

Rikuo Takano

Takeshi Kasubuchi

Koji Katamoto

Yukihiko Ueno

Isao Fujimoto

Tsuyoshi Miyamoto

Yuichi Kazaki

Koichi Moriyama

Yutaka Ohta

Etsuzi Nukushina

Mikio Osaki

Fumio Satoh

Kyouichi Takata

Mihoko Okada

Katsumi Nakanishi

Etsuji Nukushina

Shin-ichirou Ohhashi

The present invention is directed to the provision of an image forming apparatus capable of effectively preventing the formation of images related to illegal conducts by making provisions so that, even in situations where images can be formed based on image data outputted from any arbitrary image output apparatus, the image output apparatus which outputted the image data can be identified without fail. When image data is inputted from a portable image output apparatus, first it is checked whether identification information has been inputted together with the image data, then an image of an identification pattern is created, and image formation is performed based on image data obtained by attaching the image data of the identification pattern to the input image data. On the other hand, when image data is inputted from a fixed image output apparatus, first it is checked whether identification pattern data is included in a designated position in the image data, and then image formation is performed based on the input image data. The image thus formed by the digital copying machine contains the image of the identification pattern by which the image supply device that outputted the source image data is identified.

Image forming apparatus using image data and identification information in relation to an output apparatus

Image forming apparatus using image data and identification information in relation to an arbitrary image output apparatus

An image processing apparatus having an image judgement section for judging whether or not a specific pattern image is included in at least a part of the image data input from an image input section, and a central processing unit for controlling the output of an image based on the judgement result by the image judgement section, wherein the image judgement section comprises a plurality of specific pattern image control tables for controlling different specific pattern images, respectively, and every time image data is input from the image data input section, the order of the plurality of specific pattern image control tables is changed over to perform the image judgement.

Image processing apparatus

Developing devices are provided adjacent to a light sensitive element. An intermediate transfer drum is provided adjacent to the light sensitive elements. After exposure of the light sensitive element, a first color or third color image is formed on the light sensitive element. On the other hand, after exposure of the light sensitive element, a second color or fourth color image can be formed on the light sensitive element. The first color image is transferred from the transfer unit to the intermediate transfer drum at the first transfer portion, and the second color image is transferred from the transfer unit at the second transfer portion so as to be superimposed on the first color image. Similarly, the third color image is transferred so as to be superimposed on the second image and the fourth color image is transferred so as to be superimposed on the third color image to the intermediate transfer drum. Accordingly, the first to fourth color images are superimposed. Thereby, downsizing of the device and cost reduction are achieved and image formation speed is facilitated.

Image formation apparatus and image formation method

In conventional color digital copy machines, when copying in color mode, the polygon mirror of the laser beam scanner for black, which is driven at a higher speed than those of the other colors, is switched to a slower speed in conformity with the speed of the polygon mirrors for the other colors. However, a drawback of this structure is that, especially when switching from monochrome to color mode, the time required to obtain the first copy is lengthened, and the operating efficiency of copying is poor. In the present invention, when copying in color mode, the rotation speed of the polygon mirror of the laser scanner unit for black is not changed at all, but, by skipping certain mirror surfaces of the polygon mirror, and/or by skipping certain of a plurality of laser light sources, the scanning density of the laser scanner unit for black can be brought into conformity with that of the laser scanner units for the other colors.

color image-forming device

An object of the present invention is to offer an image stabilizer device capable of effectively improving quality of images produced by an image forming apparatus of a type that changes the size of a basic pixel by controlling an irradiation time of write-in light, and to offer a pattern image reader device used for the purpose. A pattern image reader device,is constituted by a reader unit,that at least contains a semiconductor laser,, converging lens,, and photosensor,for reading the amount of reflected light, and the driving section,that contains a drive coil,for moving the reader unit,in the principal scanning direction, and can measure on the order of microns the size of a toner image formed on the surface of a transfer and transport belt,in the principal scanning direction by monitoring the output of the photosensor,while moving in the principal scanning direction under the control by the CPU,. The CPU,thereafter corrects lookup tables,to,according to the dot diameter measured in the principal scanning direction.

Pattern image reader device and image stabilizer device incorporated in image forming apparatus

A conventional image forming device having a plurality of image optical scanning recording sections has had a drawback of being incapable of correcting printing positions of the image optical scanning recording sections with high precision by using a small-scale circuit. In the case of an image forming device of the present invention, a variable clock generator 114 having a voltage control oscillator (VCO) 114a is provided therein as reference clock signal generating means of laser control system of each of image optical scanning recording sections (LSU) for cyan, yellow, and magenta. By so doing, during an invalid printing period prior to a valid printing period, frequencies of the reference clock signals of the LSUs for cyan, yellow, and magenta are adjusted in accordance with offsets of printing start positions of these LSUs with respect to that of the LSU for black, so that printing offsets are eliminated. As a result, the printing start positions are made to coincide with each other with high precision even with a small-scale circuit.

Image forming device

An image data input portion captures one line of data. The captured RGB data is color-converted into image information of a different set of colors, through the image processing portion. The converted data is written at a set up address on an HD. One page of image information is written onto the HD whilst the HD's address is sequentially incremented by 2. When two colors of data need to be retrieved in parallel from the HD, the data of the colors can be alternately written in. A CPU controls tandem recording units Pa, Pb, Pc and Pd so as to perform printing of respective colors, with a time shift one to the next of a period equal to the pitch of photoreceptor recording units.

Color image forming apparatus

The present invention is intended to reduce a f.theta. correction error by correcting an error of an object scanning speed which is produced because a reflecting point of a laser beam moves on a polygon mirror. In an inventive laser scanner, laser light emitted from a laser oscillator is condensed into a beam by a condenser lens at first. This laser beam is reflected by a polygon mirror rotated by a scanning section and is reflected again to a photoreceptor by a curved reflecting mirror. A curved profile of a reflecting plane of the curved reflecting mirror in the main scanning direction is formed so as to be asymmetrical on right and left bounding about a scanning center point. Thereby, variation of speed for scanning the curved reflecting mirror by the light reflected by the polygon mirror may be canceled by the curved reflecting mirror and a speed for scanning the object may be fixed almost at a predetermined speed.

Optical scanning apparatus

An image forming apparatus is designed to compensate for voltage to be applied to an exposure lamp and a charger in accordance with changes in the density of a toner image formed on a photoreceptor that occur from its initial state to its final state after an image forming operation. More specifically, the density of a reference toner image is measured by a toner-density sensor. The amount of change in the density is measured beginning with its initial state by a subtracter, and the amount of compensation for the voltage required for obtaining the optimum image quality is found. By using these amounts of compensation as teaching data, learning is made as to the relationship between the amount of change in the density and the amount of compensation in a neurocomputer. Upon forming an image, the neurocomputer executes operations in accordance with the contents of the learning based on an inputted amount of change in density, and finds an appropriate amount of compensation. With this arrangement, it is possible to constantly obtain copied images having stable image quality, and to lower the cost of image forming apparatuses by reducing the number of parts used for the sensors or other devices.

Image forming apparatus having an image-quality correction function

An electrophotographic copying apparatus comprises a photosensitive member (4) exposed by light reflected from an original to form an image of the original thereon, mechanism (13) for developing the image on the photosensitive member with toner (9, 10, 11, 12) to produce a toner image corresponding the image mechanism (24) for transferring the toner image onto a transfer material, mechanism (26) for fixing the toner image transferred on the transfer material, mechanism (27) for producing a signal which represents that high surface glossiness of the image copy is required, and mechanism (31, 32) for feeding the transfer material in a first path when the signal is produced, the transfer material being fixed fully, and for feeding the transfer material in a second path shorter than the first path when the signal is not produced.

Electrophotographic copying apparatus

A developing apparatus which includes a plurality of developing units individually provided with sensors for detecting amount of toner accommodated therein, includes a judging device for judging whether or not sensor outputs of other developing units are below a replenishable amount when a sensor output of one developing unit falls below a replenishing requiring amount, and a replenishing display device for urging toner replenishment, based on the result of the above judgement, with respect to the developing unit having the sensor output below the replenishing requiring amount and the developing unit whose sensor output is below the replenishable amount.

Developing apparatus

A developing apparatus which includes a plurality of developing units individually provided with sensors for detecting amounts of toner accommodated therein, includes a judging device for judging whether or not sensor outputs of other developing units are below a replenishable amount when a sensor output of one developing unit falls below a replenishing requiring amount, and a replenishing display device for urging toner replenishment, based on the result of the above judgement, with respect to the developing unit having the sensor output below the replenishing requiring amount and the developing unit whose sensor output is below the replenishable amount.

An electrophotographic apparatus is provided with a developing device accommodating a plurality of developer tanks and a system for preventing erroneous mounting of these developer tanks. The developer tanks contain respective developers different in color from each other and are detachably mounted in respective predetermined mounting portions of the developing device. The system includes a connector formed on each of the developer tanks, a fixed connector formed on each of the mounting portions of the developing device and a controller for outputting at least one discrimination signal and judging whether or not the discrimination signal is inputted into the controller through at least one set of connectors. The connectors in each set are electrically connected with each other when each developer tank is properly mounted in its predetermined mounting portion of the developing device.

System for preventing erroneous mounting of developer tanks accommodated

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Nara, Japan

Yoichi Shimazawa