Sharp Kabushiki Kaisha Corporation

Hirofumi Sakita

Syouichi Fujita

Hideji Saiko

Kouichi Takenouchi

Mitsuru Tokuyama

Masato Asanuma

Itaru Kawabata

Yasuyuki Ishiguro

Masatsugu Nakamura

Hiroo Naoi

Toshio Nishino

Hideyuki Nishimura

Masaaki Ohtsuki

Hirokazu Izumi

Hisaaki Kobayashi

Tadashi Nakamura

Takahiko Kimura

Yoshiaki Akazawa

Yasutaka Maeda

Takeshi Wakabayashi

Jitsuo Masuda

Motoyuki Itoyama

Yoshiaki Sanada

Naotaka Funayama

Hiroshi Kawamoto

Toshihiko Murakami

Atsushi Kurimoto

Kouji Shinkawa

Takeshi Murata

Makoto Uehara

Eiji Sato

Yoshinori Ohtsuka

Kanshiro Okamoto

Shuichi Morikuni

Mihoko Okada

Tao Ou

A toner supply device for supplying toner to a developing device includes: a first toner supply portion for supplying toner to a developing hopper; a second toner supply portion for supplying the stored toner to the first toner supply portion; a first toner supply driver for driving the first toner supply portion; a first residual toner quantity detector for detecting the residual toner quantity in the first toner supply portion; a second toner supply driver for driving the second toner supply portion; a second residual toner quantity detector for detecting the residual toner quantity in the second toner supply portion; and a controller for controlling the drives of the first and second toner supply drivers by switching on and off the drives of the first and second toner supply drivers in accordance with the residual toner quantities detected by the first and second residual toner quantity detectors.

Toner supply device, developing device and image forming apparatus with residual quantity of toner based control

An image forming apparatus capable of selecting a toner cartridge from a plurality of toner cartridges containing toner of an identical color preferentially without interrupting an image forming action of the apparatus. When a toner density of the toner in a developer container becomes low, a control section drives a toner supply section in response to information on the remaining amount of the toner contained in the toner cartridges, so that the toner may be supplied from the toner cartridge having the least remaining amount.

Image forming apparatus for supplying toner from one of a plurality of toner cartridges

A reference developing image is formed on a photoreceptor drum under an image forming condition measured in advance, and the density of this reference developing image is detected. A development bias voltage is corrected based on the detection result, and when a correction value of the development bias voltage exceeds a predetermined range, a reference output voltage of an ATC sensor for detecting the density of toner in a developing device is corrected based on the detected value of humidity around the developing device, the frequency of use of the apparatus, and the agitation stress of developer.

Image forming method and image forming device

The image forming apparatus according to the present invention detects the amount of remaining toner by using (i) the result of calculation carried out by a toner supply amount calculation section based on an accumulated rotational time measurement section in a region where the amount of remaining toner is not less than a predetermined amount and toner supply is stabilized, (ii) the result of calculation carried out by a pixel count section in a region where the amount of remaining toner gets small and the amount of toner supply gets uneven, and (iii) the result of ATC carried out by a toner density control section. As a result, it is possible to exactly detect the amount of remaining toner without providing a special remaining toner detection device.

Image forming apparatus and method for detecting amount of remaining toner

A device has a process cartridge that includes a main cartridge accommodating a photosensitive body and a toner cartridge for use in replenis`hing toner as a precondition, is to precisely judge the service life of a photosensitive body and replacement timing of a main cartridge. Whether a predetermined condition is satisfied or not is judged with reference to a recording sheets count value G, a total operation time Tt and a toner cartridge related operation time Tx of the photosensitive drum, and a toner replenishing time Ts. In cases where a predetermined condition is satisfied, a message is displayed to urge the user to replace the process cartridge or the toner cartridge. When the toner is used up, the recording operation is inhibited, and an instruction to replace the process cartridge or the toner cartridge is displayed. Consequently, it is possible to accurately replace the photosensitive drum and toner cartridge at their respective adequate replacement timings.

Image forming apparatus with detachable mounting process cartridge

In an image-forming section, a communication device is attached to the top surface of a developing cartridge that is detachably attached to a developing device, and a main body side communication device is attached to a copying machine main body in a manner so as to face the top portion of the communication device. When a loading operation of the developing cartridge to the copying machine main body is carried out, the main body side communication device detects this operation, and sends an electric wave for an electrical supply to the developing cartridge. The communication device transmits individual information of the developing cartridge by means of radio waves, and the main body side communication device receives, demodulates and reads this information. Based upon the results thereof, it makes a judgment as to conformity and suitability of the developing cartridge, and displays the results of the judgement or gives a warning as to the results. Thus, it becomes possible to prevent an erroneous insertion of any unit to the image-forming apparatus main body by using a method with high reliability at low costs. It is possible to provide not only the developer supplying container, but also image-forming apparatus units serving as various units related to image-forming processes and an image-forming apparatus using such units.

Image-forming apparatus unit and image-forming apparatus

An image-forming apparatus is provided with: a rotatable photoreceptor; a charging device for charging the surface of the photoreceptor to a predetermined electric potential. A device for corona discharging, the charging device has a control electrode for controlling the quantity of corona ions that are allowed to reach the photoreceptor. A latent image forming device for forming an electrostatic latent image on the photoreceptor that has been charged by the charging device by use of light irradiation. There is a developing device for developing the electrostatic latent image by using a developer; and a control voltage supply device for supplying a control voltage to the control electrode and for switching the control voltage to a plurality of stages from a low-voltage side to a high-voltage side until the surface electric potential of the photoreceptor has risen to a predetermined electric potential. This image-forming apparatus prevents carrier rise at the time of a rise of the photoreceptor surface electric potential.

Image-forming apparatus which forms images by using a developer

To solve problems that the amount of reuse toner increases with time recovery of reuse toner is efficiently achieved while forming an image of high quality. In a toner replenishing apparatus, toner recovered by a cleaning unit is conveyed via conveying device and contained in a recovery toner container. When an amount of the recovery toner exceeds a predetermined capacity of the recovery toner container, the recovery toner flows into a fresh toner container over an upper edge of a partition wall. Fresh toner and recovery toner are replenished to a developing unit via a fresh toner replenishing roller and a recovery toner replenishing roller, respectively, and the ratio between fresh toner and recovery toner is selected so that the fresh toner occupies a larger part than the recovery toner. This ratio is controlled on the basis of the cumulative rotation time of a photoconductor drum counted by a counting device.

Toner replenishing apparatus and image forming apparatus equipped with same

A developing unit and an image forming apparatus includes drive and control mechanisms for the conveyance of collected toner and fresh toner in an uncomplicated structure and an uncomplicated toner supplying roller structure for the reduction in manufacturing cost. Fresh toner and collected toner stored in housing parts of a toner housing are discharged from an outlet via openings formed in a partitioning member for forwarding to a developing section by a toner supplying roller disposed to confront the outlet. The toner supplying roller is provided in common to fresh toner and collected toner. The toner supplying roller includes a single rotary shaft and a plurality of composite members which are fit into the rotary shaft. Each of the composite members has a cylindrical hollow body and a cylindrical elastic body which is fit onto the outer peripheral surface of the hollow body. The composite members are disposed correspondingly to the housing parts.

Developing unit and image forming apparatus

In an image forming apparatus having a developing unit for developing an image using toner, a toner box for withholding the toner, and a toner transportation section for transporting the toner withheld in the toner box to the developing unit, the toner transportation section includes a transportation screw portion having formed a spiral blade section on its shaft, a pipe section for controlling a toner transportation route by covering the transportation screw portion of the toner transportation section, and a toner flow suppressing section for suppressing flow of the toner from a space between the transportation screw and pipe section. Consequently, a toner transportation opening formed near the transportation section can be closed, and therefore, the flowing of toner into the developing unit can be controlled or reduced by a simple and inexpensive arrangement.

Image forming apparatus having developer supply device

A developing device having a reduced size in the horizontal direction and in which a developing agent is transported with stirring along a circulating route inside a developing tank to effectively mix newly added toner therewith and stir the mixture. A developing tank for storing developing agent therein is horizontally divided with a partition member thereby providing an upper chamber and a lower chamber. A developer roller and a stirring roller are disposed in the lower chamber. Two screw rollers are disposed in the upper chamber. An inlet opening is formed between an end of the partition member and a regulating member for restricting a layer if the developing agent adsorbed to the developing roller. A developing agent removed by the restricting member is fed through an inlet opening to the screw rollers in the upper chamber. The developing agent is mixed with fresh toner supplied through a supply inlet and transported with being stirred by the screw roller in its axial direction. Then, the developing agent is transferred to the screw roller disposed parallel to the screw roller and it is further transported and returned to the stirring roller in the lower chamber through a return port provided opposite to the screw roller. The compact construction of the developing device is realized by arranging screw rollers for stirring and transporting toner in the upper chamber.

Developing device having a reduced width in the horizontal direction

The present invention relates to image forming device such as copying machines and laser printers, which use an electrophotographic (xerognaphic) process. A simple control method without using any additional complex means can equalize a surface potentional of a light-sensitive drum to keep a light-quality of an image formed even for the first rotation of the light-sensitive drum. A charge-removal prohibiting means, a charge-potentional changing means and a developing bias-potentional changing means are controlled in accordance with an extent of a change of a surface potential of a light-sensitive body, which depends upon a light fatigue and an ambient temperature of the light-sensitive body and/or a pause after a preceding image process.

Image forming device with residual charge removal control

A method for preparing an electrophotographic printing-use developer by mixing components of toner material, fusing and kneading the toner material, and then crushing and classifying the toner material, includes the step of arranging carbon black which is one of the components of the toner material to contain water before the mixing step. This arrangement permits even dispersion of water in the mixture of the components, prevents the flowability of the mixture from being lowered, and achieves stable kneading. Therefore, improved dispersion of the components is achieved. Since water adsorption is stable, water-treated carbon showing reduced water segregation is obtained. Consequently, high quality less foggy images with high resolution are obtained.

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Tenri, Japan

Hirofumi Sakita