Sharp Kabushiki Kaisha Corporation

Tohru Sakuwa

Toshiaki Kagawa

Kouji Shinkawa

Kazuya Yoshimura

Yasuhiro Nishimura

Kohji Shinkawa

Tomohisa Matsushita

Haruo Yamamoto

Satoshi Nishigaki

Takuya Iwanami

A process unit includes: a photosensitive drum on a surface of which a toner image is formed; a charging roller being pressed against the photosensitive drum so as to charge the photosensitive drum; a cleaning roller being pressed against the charging roller so as to clean the charging roller; and at least one biasing member biasing the charging roller or the cleaning roller. A central axis of the photosensitive drum is located at a position not overlapping with a central axis line passing through a central axis of the charging roller and a central axis of the cleaning roller. A biasing direction of the at least one biasing member is on a same line as the central axis line.

Process unit and image forming apparatus

In an image forming apparatus, a cleaning portion has a discharge pipe that guides toner that has been collected from a peripheral surface of a photoreceptor drum as waste toner to the outside of a process unit. The discharge pipe is drawn from a side surface of the process unit and includes at a tip portion a discharge port that discharges the waste toner. A restricting portion is arranged on a side surface of the discharge pipe, between a position corresponding to an insertion port and the discharge port, and restricts a flow of air moving from the discharge port to the insertion port. The insertion port is provided on a same surface as the side surface of the process unit from which the discharge pipe is drawn. And the insertion port is configured to be inserted by a cleaning tool for the electrode.

Image forming apparatus capable of preventing waste toner from entering into processing unit

To provide a charging device which can be reduced in size and increased in speed while suppressing the occurrence of charging irregularities on the surface of the photosensitive drum, a process cartridge, and an image forming apparatus. A charging deviceY which charges a surface of a photosensitive drumY, comprises a discharge electrodewhich applies a potential to the surface of the photosensitive drumY and charges the surface, and a grid electrodewith a porous place shape disposed between the discharge electrodeand the surface of the photosensitive drumY so as to face the surface of the photosensitive drumY and which controls the charging potential of the surface, wherein the grid electrodeis divided into a plurality of regions approximately parallel to a direction orthogonal to a direction of rotation of the photosensitive drumY, and the plurality of regions is characterized in that an opening ratio of a midstream regionclose to the photosensitive drumY is greater than an opening ratios of an upstream regionand a downstream region

Charging device, process cartridge, and image forming apparatus

An exhaust device provided in an image forming apparatus is provided. In the exhaust device, an initial condition setting unit sets an initial drive output value of a exhaust fan at a time of starting an image forming operation based on a calculation value calculated by an image bearing member drive counting unit. A drive unit drives the exhaust fan to start to discharge air in the image forming apparatus. A continuation condition setting unit sets a continuation drive condition at a time of continuously driving the exhaust fan from a point in time when ending the image forming operation based on a count value of the number of image formation by the job counting unit. A drive unit drives the exhaust fan with the continuation drive condition to continuously discharge the air in the image forming apparatus.

Exhaust device, image forming apparatus including the same, recording medium on which control program for exhaust device is recorded

An object of the present invention is to provide a charging roller (i) which includes a rubber member whose surface is subjected to a hardening treatment using a solvent containing at least an isocyanate compound and (ii) which can prevent leakage of an ionic conductive agent even if the charging roller is placed under conditions of high temperature and high humidity for a long time. The charging roller is made by forming a rubber layer on a metal core. The rubber layer is an epichlorohydrin based rubber base material to which an ionic conductive agent is added, the rubber layer being subjected to a surface treatment by applying a solution containing the isocyanate compound and heating it. This surface treatment is carried out under such conditions that a coefficient of dynamic friction at a contact portion between the rubber layer and a photoreceptor becomes 0.4 or less.

Charging roller, process cartridge and image forming apparatus

A cleaning deviceincludes: contact and release systemwhich switches a position of a cleaning rollerbetween a position where the cleaning rolleris in contact with a charging rollerand a position where the cleaning rolleris separated from the charging roller; and a voltage selecting sectionwhich switches a voltage to be applied to the charging rollerfrom a DC voltage to an AC voltage during the rotation of a photoreceptor. The contact and release systembrings the cleaning rollerinto contact with the charging rollerat the application of the AC voltage to the charging roller. This makes it possible to enhance performance on cleaning of the charging roller.

Cleaning device which cleans a contact charging member that is disposed in contact with an image bearing member

An image forming apparatus in which a charging roller charges an image carrier to which a lubricant is applied prevents slip of the charging roller. The charging roller is composed of a metal core and a rubber layer mainly made of an epichlorohydrin rubber formed around the metal core. A surface of this rubber layer is hardened with a surface treating solution containing an isocyanate compound. The surface of this rubber layer is also subjected to three abrading processes including two stone grinding processes and one lapping process so that a ten-point height of irregularities Rz thereof becomes 11 &#x3bc;m or more.

Image forming apparatus, process cartridge used therein, and production method of charging roller

When image forming is performed by a photosensitive drum according to operating conditions corresponding to an image forming mode selected out of a predetermined plurality of candidates, an actual cumulative number of printed sheets Pi is corrected and recorded based on the image forming mode (monochrome mode or color mode; low-temperature and low humidity ambience mode or other ambience mode) selected at the time of each image forming (S) and an adjustment volume (ko&#xd7;Pia) of a charging applied voltage Ey is calculated and the charging applied voltage Ey is set based on a corrected cumulative number of printed sheets Pia (S). As a result, the charging applied voltage Ey to a charging unit is changed according to a cumulative number of printed sheets and at the same time, a pace of change thereof is adjusted based on the image forming mode.

Changing the charging applied voltage control in an image forming apparatus based on an increase in the cumulative number of times of execution of image forming

The invention delivers a charging roller which is capable of preventing current leakage to a photoreceptor throughout life-time and which has a stable resistance value throughout life-time. The charging roller contains a metal core and a rubber layer formed on the core. The rubber layer is an epichlorohydrin-based rubber base material to which an electronic conductive agent and an ionic conductive agent are added. The rubber layer is subjected to surface processing by spraying the surface with a solution containing an isocyanate compound and heating. The amount of the electronic conductive agent added to the rubber base material is limited so that a volume resistivity when only the electronic conductive agent is added to the rubber base material is 1.46&#xd7;10&#x3a9;&#xb7;cm or greater. In addition, the amount of the added ionic conductive agent is increased so that a volume resistivity when the electronic conductive agent and the ionic conductive agent are added to the rubber base material is 1.93&#xd7;10&#x3a9;&#xb7;cm or less.

Charging roller and image forming apparatus incorporating same

An image forming method, device and a recording agent for forming an image through subtractive color mixing by using ink of plural color components different in hue. The ink is created by mixing a first coloring agent expressing one of the color components and a second coloring agent identical in hue to the first coloring agent. The ink has a higher spectral reflectance than a spectral reflectance of the first coloring agent.

Recording agent, image forming device, and image forming method

A liquid crystal display device, including: a first substrate; a second substrate; opposing the first substrate; a liquid crystal layer interposed between the first substrate and the second substrate; a reflection film formed on one side of the second substrate that is closer to the liquid crystal layer; and a color filter formed on the reflection film, wherein: a plurality of pixel regions are arranged in a matrix pattern, each of the pixel regions including a reflection region where light coming from the first substrate side is reflected by the reflection film back to the first substrate side, and a transmission region where light coming from the second substrate side is transmitted to the first substrate side; and the color filter includes an opening in the reflection region.

Transmission/reflection type color liquid crystal display device

An object of the invention is to provide a liquid crystal display device using plastic substrates in which deformation such as warpage and distortion hardly occurs. The reflection type liquid crystal display device includes a light transmitting plastic substrate and a plastic substrate provided with a reflecting layer. The substrates are positioned facing each other to be kept fixed relative to each other with a predetermined space therebetween defined by spacers or the like. A liquid crystal layer is formed in the space between the substrates and sealed with a sealing agent. A polarizing plate along with an adhesive is attached to the outer surface of the light transmitting plastic substrate, and a polycarbonate substrate along with an adhesive is attached to the outer surface of the reflector-attached plastic substrate.

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Nara, Japan

Tohru Sakuwa