Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Naoki Toyoshi

Tateki Oka

Tomoaki Yokoyama

Hiroshi Okamoto

Kenji Tabuchi

Kaoru Takebe

Hiroshi Goto

Hirofumi Hasegawa

Shinichi Takemoto

Hiroshi Mizuno

Akihito Ikegawa

Hiroshi Murasaki

Narutaka Yoshida

Kentaro Katori

Tsugihito Yoshiyama

Tsutomu Yamazaki

Kouichi Etou

Mineyuki Sako

Shuichi Nakagawa

Shizuo Yuge

Hitoshi Sekino

Hisashi Myochin

Shoichi Tsuge

Susumu Sakakibara

Taisuke Nagao

Kunio Toda

Moriyoshi Matsushiro

Kenji Miyashita

Takeki Oka

An apparatus and method for processing an image which are capable of producing a printed image satisfying both resolution and reproducibility of gradation. This method admits as an input the RGB data of the size of one pixel and converts this input into lightness data and density data. When a target pixel is determined to correspond to a non-edge portion, the method performs a computation for finding the remainder,of X/,and the remainder m of Y/,from the coordinates (X,Y) of the target pixel thereby deciding which of the total of nine pixels of a non-edge grade dither pattern is to be extracted, and allocates the position d(l,m) to the extracted pixel. On the other hand, when the target pixel is determined to correspond to an edge portion, an edge grade dither pattern corresponding to the density of the target pixel is allocated directly to the target pixel. The processing of conversion into the non-edge grade dither pattern d(l,m) or the processing of conversion into the edge grade dither patter which is performed as described above is carried out on all the pixels which have been read, depending on the determination of whether the target pixel corresponds to the non-edge portion or the edge portion, and the converted data obtained consequently is emitted.

Apparatus and method for processing image

The invention provides image forming method and apparatus. One embodiment of the invention is an image forming apparatus with a developing device. This apparatus also includes: (1) an electrostatic latent image carrier on which an electrostatic latent image is formed, (2) a developing roller rotatably driven in a first direction during developing, (3) a developing-roller-reverse rotator which rotates the developing roller in a second direction opposite the first direction, when the developing device moves with respect to the electrostatic latent image carrier. Another embodiment is an image forming apparatus that also includes a developer-regulating member positioned in direct contact with or close proximity to the developing roller. In this embodiment, the rotation of the developing roller in the second direction dislodges materials stuck between the developing roller and the developer-regulating member. Yet another embodiment of the invention an image forming apparatus that also includes a developing device, an electrostatic latent image carrier, a developing roller, and a developer-regulating member. This embodiment further includes a separating member coupled to at least one of the developing-regulating member and the developer roller. The separating member moves the developer-regulating member and the developing roller away from each other when the developing device moves.

Apparatus and method for removing foreign materials lodged inside an

An image forming apparatus in which a light amount of an irradiation lamp for exposure or voltage value of a developing bias applied to a developing electrode is adjusted based upon density value of test toner images formed on the surface of the photosensitive member for preventing the occurrence of toner fogging.

Image forming apparatus

A developing device for developing an electrostatic latent image formed on an electrostatic latent image support member comprises a developer supplying member for supplying a developer to the electrostatic latent image support member, a developer containing portion containing the developer to be supplied to the developer supplying member, a conveying member provided in the developer containing portion for conveying the developer above the bottom part of the developer containing portion to the developer supplying member with the developer in the bottom part of the developer containing portion being left, and an agitating member provided in the developer containing portion for agitating in the developer containing portion the developer remaining in the bottom part of the developer containing portion without being conveyed by the conveying member.

Device for conveying developer in a developing device

A developing device for supplying toner particles to an electrostatic latent image support member having an electrostatic latent image formed thereon to develop the electrostatic latent image comprises a toner conveying member for conveying and supplying the toner particles to the electrostatic latent image support member having the electrostatic latent image formed thereon, a power supply for applying a predetermined developing bias voltage to said toner conveying member, and charge movement preventing means connected between the toner conveying member and the power supply for preventing charges induced in the toner conveying member as the electrostatic latent image is developed from flowing toward the power supply.

Developing device with electrically floating developing roller

A developing device having a toner carrying member for transporting toner to a photosensitive member, a toner supplying member facing to the toner carrying member with an opening therebetween for supplying toner to the toner carrying member and a seal member for substantially closing a toner path. In the developing device a scraping member is further provided in contact with the toner supplying member to scrape the toner therefrom and an accommodating space is formed by the toner carrying member, toner supplying member, seal member and scraping member. Thus the toner transported by the toner supplying member is accommodated in the accommodating space and then supplied to the toner holding member under pressure accompanied by the increase of the toner accommodated therein, whereby an adequate quantity of toner is supplied for development.

Developing device having a space for receiving and increasing pressure

A developing apparatus includes a photosensitive drum positioned in confronting relation to a developing sleeve. A toner accommodating tank is provided for supplying toner to the developing sleeve. The toner accommodating tank is divided into a small chamber and a supplementary chamber which are separated from one another by a partition which permits toner to be supplied from the supplementary chamber to the small chamber but which prevents the return of toner from the small chamber to the supplementary. A movable shutter selectively permits and prevents toner from being supplied from the supplementary chamber to the small chamber in accordance with operation of the apparatus.

Developing apparatus including a partitioning arrangement for

A developing apparatus for use in an image forming apparatus employing an electrophotographic copying process, which is capable of providing developed images of a constant image quality over a long period of operation. One of the features is an independent section for accommodating toner particles with different particle diameters within the toner hopper. Seventeen separate embodiments serve to assure an adequate mixture of small to large diameter toner particles to assure image quality.

Developing apparatus with image quality control

An electrophotographic copying process produces a photocopy having a negative image in order to highlight information in a specified area. An original image is radiated onto a photosensitive medium to form a first image. A solid block is formed in the specified area of the first image. The first image is then transferred to blank paper. The original image is then radiated onto the photosensitive medium again and a portion of the image is erased in order to form a second image. The second image is then transferred to the sheet of paper having the first image. The resulting image formed on the sheet of paper includes a highlighted second image formed in the specified area.

Image highlighting method

An image forming apparatus wherein a photosensitive layer arranged to rotate in one direction is charged by a charger, and a negative electrostatic latent image is formed thereon by an exposure unit and then is subjected to reversal development by a developing device so that a positive noticeable image can be attained. The apparatus has a scorotoron charger for charging the negative latent image which has just been formed by the exposure unit with the opposite polarity thereof. A grid of the scorotoron charger is constituted to be impressed with a voltage with the same polarity as the latent image and a value lower than that of the surface potential, and by the scorotoron charger, the potential of the non-imaged portions of the latent image is lowered around the grid voltage. Further, the developing device is constituted to be impressed with a developing bias voltage with the same polarity as the latent image and a value lower than that of the surface potential but higher than a developing threshold value, whereby toner charged with the same polarity as that charged by the charger sticks to the imaged portions with potential lower than the developing bias voltage, resulting in a positive toner image with sharp line widths.

Electrophotographic image forming apparatus

A copying apparatus in which a developing bias voltage to be applied to a developing sleeve by a power source is changed to adjust the density of a reproduced image, while the electric potential difference between the developing sleeve and a toner supply roller is kept constant. As a result, a density of toner on the developing sleeve is kept constant. Therefore, a development is effected under the condition in which the density of the toner is constant, so that the tone of the image of an original document is reproduced in a desired density.

Developing apparatus with variable developing bias voltage

By utilizing an electrophotographic image forming process, a reversal image can be obtained in the following manner:

Reversal image forming method

An image editing method utilizing an electrophotographic process, which method includes a first charging step of charging a photosensitive medium; a step of projecting an image onto the charged photosensitive medium to form an electrostatic latent image; a first developing step of developing the electrostatic latent image into a first powder image by the use of a first toner material having the same polarity as the charged polarity; a first transferring step of transferring the powder image onto a copying paper; a second charging step of again charging the photosensitive medium to a polarity the same as that of the charge established during the first charging step; a step of radiating rays of light to the charged photosensitive medium to remove the electrostatic charge at a specificed area of the photosensitive medium; a second developing step of developing the specified area of the photosensitive medium by the use of a second toner material different in color from the first toner material to form a second powder image; and a second transferring step of transferring the second powder image onto said copying paper so as to cover the first powder image which has been transferred onto the copying paper.

Image editing method

An image forming apparatus for use in an electrophotographic copying process and an image forming method for the apparatus, which are arranged to reproduce an image portion of an original document by a black developing material on a white paper sheet when an area of the image portion of the original document is below a predetermined level, and also, reproducing a background portion of the image by a white developing material on a black paper sheet when the area of the image portion of the original document is above the predetermined level, and thus, the black developing material or white developing material is selectively used according to percentages of image areas on the original document.

Image forming apparatus and image forming method employed therefor

The disclosure relates to a method, using an electrophotographic system, including a first process of transferring the image of an original document to a copy sheet and a second process of transferring a half-tone solid on a specified region of the image on the copy sheet transferred at the first process. Accordingly, for example, when a copy sheet is white, a black toner is used in the first image forming process, and a white toner is used in the second image forming process, a white half-tone solid of the white toner is superimposed on the black toner image. As a result, the black toner image formed on the specified region looks soft half-tone.

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Osaka, Japan

Naoki Toyoshi