Ricoh Company, Ltd.

Shuuichi Endoh

Osamu Endou

Nobuhiko Umezawa

Shinya Tanaka

Masahide Harada

Masato Iio

Kenji Sato

Ichiro Komuro

Yoshihiro Abe

Toru Ohmine

Junichi Mizawa

Masato Mukai

Yasuko Yoshikawa

Hiroyuki Fushimi

Takahiro Honda

Yohsuke Saitoh

A positional deviation correction pattern includes a first and second pattern image portions adjacent in a sub-scanning direction at the same position in a main-scanning direction, with the same width in the main-scanning direction. Each image portion includes a first side extending in the sub-scanning direction, a second side continuing from one end of the first side and extending in a direction intersecting the sub-scanning direction, and a third side continuing from the other end and extending in a direction intersecting both the sub-scanning direction and the second side. The second sides have the same inclination angle to a virtual line parallel to the main-scanning direction. The third sides have the same inclination angle to the virtual line. A length of one image portion in the sub-scanning direction gradually increases from one end to the other end in the main-scanning direction, a length of the other image portion gradually decreases.

Positional deviation correction pattern, method of forming positional deviation correction pattern, and image forming apparatus

An image forming apparatus includes an image bearer to bear a latent electrostatic image thereon, a developing device to supply a development agent to the latent electrostatic image to obtain a visible image, a transfer roller to contact the image bearer to transfer the visible image to a recording medium, a replenishing device to replenish the developing device with the development agent when a density value read from a density detection pattern formed on the image bearer by the developing device is equal to or less than a threshold, a processing device to conduct a predetermined processing to reduce attachment of the development agent to the transfer roller, and a control device to control the number of times the predetermined processing is performed or processing time in performing the predetermined processing for the processing device, based on whether there is replenishment of the development agent to the developing device.

Image forming apparatus with controller to reduce attachment of development agent to transfer roller

An image forming apparatus including an image bearing member and a developing device configured to develop an electrostatic image on the image bearing member with a toner to form a toner image thereon and including a developing unit configured to develop the electrostatic image, and a toner cartridge configured to supply the toner to the developing unit through at least one opening, wherein the developing device circulates the toner between the toner cartridge and the developing unit through the at least one opening, and wherein the internal temperature of the hopper is higher than that of the cartridge and the ratio of a charge quantity distribution parameter of the toner under a condition of 45&#xb0; C. and 54% RH to that under a condition of 25&#xb0; C. and 54% RH is greater than 0.9 and less than 1.5.

Image forming method and apparatus, and developing device and process cartridge therefor

A developing unit develops a latent image on an image carrier with toner. A toner cartridge is detachably arranged in parallel with the developing unit, and supplies the toner to the developing unit. An opening is disposed between the developing unit and the toner cartridge, through which the toner passes. The toner cartridge includes a space forming unit that forms a space in the toner stored in the toner cartridge. The space allows the toner to flow into from the developing unit.

Toner change and flow stabilizing developing device, process cartridge, and image forming apparatus

An image forming apparatus includes an image carrying member, a charging device for charging the image carrying member, an exposure device for writing a latent image on the image carrying member, a development device for developing the latent image into a visible image, a transfer device for transferring the visible image to a recording medium, a cleaning device for cleaning the image carrying member, and a fixing device for fixing the visible image on the recording medium. The development device includes a development unit, a toner cartridge, and a control mechanism. The toner cartridge supplies toner to the development unit which develops the latent image into the visible image. The control mechanism controls supply and discharge of the toner between the development unit and the toner cartridge. The development device moves at an acceleration of approximately 1 m/sin directions of supplying and discharging the toner for a predetermined time.

Image forming method and apparatus capable of enhancing toner mobility

A developing device for an image forming apparatus of the present invention includes an image carrier performing endless movement while carrying a developer in the form of a layer thereon, and a regulating member for regulating the thickness of the layer. Toner stored in the developing device is covered with an additive whose particle size is less than 2 &mgr;m. The regulating member is implemented as a doctor roller having a surface roughness Rz equal to or greater than the above particle size, but smaller than 2 &mgr;m. The doctor roller is pressed against a developing roller or developer carrier by a preselected pressure, forming a nip for development. The developing device reduces irregular development ascribable to impurities caught at a regulating position assigned to the doctor roller more than a conventional developing device using a doctor blade as a regulating member. In addition, the developing device obviates irregular development in the form of fine stripes ascribable to stripe-like irregularities formed in the developer layer existing on the developing roller.

Developing device for an image forming apparatus

A development apparatus includes a development roller, a supplying roller, and a toner layer regulating member. The development roller contacts an image carrying member and develops an electrostatic latent image into a toner image on the image carrying member. The development roller may be made of aluminum and is rotatably mounted in the apparatus. The supplying roller supplies toner to the development roller. The toner layer regulating member regulates the toner to form a thin film on the development roller. The toner layer regulating member has a roller shape, a surface roughness R in a range of from 0.5 &mgr;m to 2 &mgr;m, and a dynamic friction coefficient in a range of from 0.1 to 0.8.

Method and apparatus for image developing capable of effectively forming an even development agent layer

A developing device for an image forming apparatus of the present invention includes an image carrier performing endless movement while carrying a developer in the form of a layer thereon, and a regulating member for regulating the thickness of the layer Toner stored in the developing device is covered with an additive whose particle size is less than 2 &mgr;m. The regulating member is implemented as a doctor roller having a surface roughness Rz equal to or greater than the above particle size, but smaller than 2 &mgr;m. The doctor roller is pressed against a developing roller or developer carrier by a preselected pressure, forming a nip for development The developing device reduces irregular development ascribable to impurities caught at a regulating position assigned to the doctor roller more than a conventional developing device using a doctor blade as a regulating member. In addition, the developing device obviates irregular development in the form of fine stripes ascribable to stripe-like irregularities formed in the developer layer existing on the developing roller.

An image forming apparatus including a photoconductive member, a charging member, a development mechanism, a transfer mechanism, and a power supply source. The development mechanism develops an image on the photoconductive member. The toner is normally charged with a voltage having a same polarity as the charge of the photoconductive member. The transfer mechanism includes a transfer roller to transfer the developed image from the photoconductive member onto a recording sheet. The power supply source supplies a voltage, having the same polarity as the voltage applied during a normal transfer operation, to the transfer roller when a region of the surface of the photoconductive member passes through a development region without a performance of a development operation and reaches a transfer region under a condition in which no recording sheet exists therebetween.

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Saitama, Japan

Shuuichi Endoh