Sharp Kabushiki Kaisha Corporation

Yuhi Yui

Eiichi Kido

Shigeyuki Wakada

Hiroshi Kinashi

Itaru Kawabata

Kouichi Irihara

Yukinori Andou

Yoshiharu Tsujimoto

Satoshi Murakami

Toyokazu Mori

Toshihiro Ota

Syoichiro Yoshiura

Katsumi Adachi

Masaru Tsuji

Takashi Hayakawa

Toshihide Ohgoshi

Hiroaki Yoshida

Keizo Fukunaga

Teruhiko Noguchi

Hiroshige Araki

Shinji Imagawa

Yasuo Imai

Keiji Katoh

Yoshikazu Kawasaki

Tokio Awata

Yuji Okamoto

Hiroshi Ishii

Masahiko Aiba

Masatsugu Nakamura

Jitsuo Masuda

Shunju Anzai

Iwakazu Honda

Koichi Moriyama

Takahiro Kawakami

Yoshinori Ohtsuka

Ken-ichi Morimoto

Koichi Irihara

Syunju Anzai

Tooru Nakata

Kouichi Moriyama

Tadashi Akiyama

An electrophotography developing apparatus has been developed which can protect a developer holder and a layer thickness control member from damage. The device also prevents internal scattering of the developer while preventing a surplus supply of the developer to both ends on the peripheral surface of the developer holder. The unique advantages of the invention are derived through the utilization of sealing members having different elastic properties, which assume both bulk removal of excess developer while providing the needed uniform developer thickness. Another embodiment of the invention has the width of the layer thickness control member in a longitudinal direction set wider than the width of the developer holder in a longitudinal direction, and both side edges of the layer thickness control member are positioned outside both side edges of the developer holder. Proper sealing is assured by having the inner side edges of the sealing member positioned inside the side edges of the developer holder and outside the side edges of the image area of the image holder.

Developing apparatus

For input image data (`A`) before conversion, each pixel is converted into N (=3) parts. In this case, the three sub-pixels of data corresponding to a recording pixel (black pixel) are converted into recording sub-pixels on both sides of the three (`B`). This eliminates the density variation within a single pixel. Therefore, it is possible to reduce the dot spacing at slanted area, for example, and hence eliminate jaggies, providing a reproduced image easily recognized.

Image forming apparatus

A developing apparatus which is equipped with a developer control member for controlling the developer on a developer supporter to a prescribed thickness, and which uses a one-component developer, characterized in that recessed sections are formed at the surface of the developer supporter to receive the developer, and the density .alpha. of particles of the developer which enter the recessed sections and the nip width L1 between the developer control member and the developer supporter satisfy the relationship: 3&lt;.alpha..multidot.L1&lt;10.

Developing apparatus having recessed sections on developing roller

A novel laser printer is disclosed, in which heat generating parts are positively cooled while reducing the noise generated by a blowing mechanism. A rotor of the motor for rotating a scanning mirror of a scanning device is surrounded by a cover. An air flow inlet port and an air flow outlet port are formed on the sides of the cover. The space in the proximity of the air flow inlet port and the air flow outlet port is divided by an air flow separation member. One longitudinal end of the air flow separation member is close to the rotor and the other longitudinal end and the lateral ends thereof are connected to the cover. The air flow separation member partially divides the rotating air flow generated around the rotor in the proximity of the air flow outlet port, and generates the discharge air flow, which in turn is discharged out of the cover. A suction air flow is introduced from the air flow inlet port to the interior of the cover which is now negative in pressure, in the form of the rotating air flow.

Laser printer capable of cooling heat generating parts as well as

A developing device attachable to and detachable from a printer using a non-magnetic monocomponent developer. Two different voltages are applied respectively to a developing roller and a toner layer thickness regulating device from a power source of the apparatus main body side through a terminal and a contacting spring. A voltage is applied directly to the developing roller from the contacting spring whereas a Zener diode is provided in a path connecting the contacting spring and toner layer thickness regulating device to apply another voltage to the toner layer thickness regulating device. The voltage applied to the toner layer thickness regulating device is dropped below the power supply voltage by the Zener voltage when a low-printing-ratio image is produced. Thus, the number of the terminals connecting the apparatus main body and developing device is reduced to one. Accordingly, defective connections at the contacting portions of the terminal can be prevented and the manufacturing costs can be reduced while a satisfactory image is produced.

Detachable developing device for providing first and second voltages for

An image forming apparatus includes: an image support medium; a charging member for charging the surface of the image support medium in contact with the surface of it; an exposure device for irradiating with light the surface of the image support medium charged by the charging member to form a static latent image; a developing device for supplying developer to the static latent image formed on the image support medium to develop the latent image and for removing the leftover developer on the image support medium; a transfer device for transferring the developer image, which has been developed on the image support medium by the developing device, to a member to be transferred; and a scraping member for scraping foreign matter such as dust and paper particles on the image support medium. The image forming apparatus is constructed such that the charging member causes the developer to adhere to the scraped foreign matter, and then the foreign matter is collected by the developing device through the image support medium. The scraping member is held by a holder which has an opening for allowing the foreign matter to pass through into the charging member housing.

Imaging forming apparatus with enhanced cleaning of residual matter

A developer cartridge for image forming apparatuses which performs development to form images with non-magnetic, one-component type developer. The cartridge includes a developing roller for supplying developer to a photoconductor drum, a developer feed roller in non-contact with the developing roller for supply developer to the developing roller, and a developer-layer thickness control member for controlling the thickness of the developer layer on the developing roller. The developer feed roller is shaped as a regular polygonal prism. Since no recesses are formed in the surface of the regular polygonal prism, driving torque does not increase when developer is scrubbed from the prism, thus ensuring consistent operation and improved image quality. Non-magnetic, one-component type developer is compressed onto the developing roller by supplying the developer via the developer feed roller into a bottleneck between the developing roller and a developer applying member. The amount of developer which passes through the bottleneck onto the developing roller is controlled by a temporary reservoir, the pressurization thereof ensuring application of the developer to the developing roller. A control roller may be used against the developing roller to lower friction of developer, thereby preventing deposition of developer on the control roller while establishing a consistent amount of developer on the developing roller.

Developing device

An image-forming apparatus including a cleaning means for selectively removing foreign matters other than developer remaining on the surface of a photoconductor drum therefrom after a transferring process. The cleaning means is provided with a foreign-matter removing roller which comes into contact with the surface of the photoconductor drum. Foreign matters, which are charged by a transferring device to have a polarity reversed to that of the charged electric potential of toner through an electric field that is exerted between the surfaces of the roller and the photoconductor drum, are allowed to adhere to the surface of the foreign-matter removing roller. As for the surface of the foreign-matter removing roller, the surface electric potential of the foreign-matter removing roller is biased farther toward the polarity of the charged toner than the surface electric potential of the photoconductor drum at the contact portion between the photoconductor drum and the foreign-matter removing roller. Thus, it becomes possible to provide an image forming apparatus which is capable of supplying images with good picture quality for a long time, by using a cleaning operation of this cleaning means.

Image-forming apparatus

A charger performs corona discharge by applying a voltage to a discharging electrode. The charger includes an electrode plate formed in the shape of a panel on the discharging electrode, a plurality of projecting portions disposed in an end portion of the electrode plate, and a plurality of projection groups formed in each of the projecting portions such that the projection groups are adjacent to each other in a thickness direction of the electrode plate.

Charger for performing a corona discharge

A charger charges a recording medium before irradiation of light to form an electrostatic latent image by irradiating light as an optical image onto a surface of the recording medium. The charger includes a discharging electrode having a plurality of projections for generating corona discharge to charge the recording medium surface, a conductive shield case having an opening face opposite to the recording medium and opposed to the discharging electrode, a holding member for holding the discharging electrode in the shield case in a state in which the discharging electrode is electrically insulated from the shield case, a conductive grid electrode electrically insulated and held between the discharging electrode and the recording medium, and a power supplying device for supplying a high voltage for discharge to the discharging electrode and setting a ratio of electric currents flowing through the grid electrode and the shield case such that these electric currents are approximately equal to each other. One form of the charger controllably moves the discharger electrode toward the recording medium for setting the value of the electric currents flowing through the grid electrode and the shield case until they are both equal to a predetermined reference value.

Corona charger for image forming apparatus providing uniform surface

An image forming apparatus shown has a developing unit and a photoconductor unit both of which are disposed in a body. The developing unit and photoconductor unit are slidably mounted adjacent to each other within the body. The mounting and positioning of the units are such as to allow the developing unit and the photoconductor unit to be successively pulled out of the body. The apparatus further includes an urging member which allows the photoconductor unit to be urged toward the developing unit. The body includes upper and lower housings and is designed so that the upper housing can be swung upward about a fulcrum on one side of the body and thereby form an opening between the upper and lower housings on the other side of the body. The apparatus is designed and the components are configured such that when the developing unit is pulled out of the body the photoconductor unit moves toward the opening and the photoconductor unit can be replaced in a large open space near the opening.

Image forming apparatus with slidably mounted developing unit and

An electrophotographic apparatus comprising a power supply, a detection means, a voltage control means, and an exposure unit control means, whereby the provision of a special discharge unit can be omitted to allow the reduction in the size and cost of the apparatus. Also, carrier attraction and toner adherence to the photoconductor can be prevented when the photoconductor is stopped after completion of an image forming operation.

Electrophotographic apparatus

An image forming apparatus has a charger; developing device; transferring device; and cleaning device which are positioned around a photoreceptor, the cleaning device and charger being integrally formed. The charger has a control unit for controlling the surface potential of the photoreceptor to be at a predetermined level in accordance with the number of rotations, or the rotating time of the photoreceptor, and/or is designed such that a predetermined voltage is applied to the cleaning device. With the above arrangement, reproduced images having constant quality can be provided for long even if the photoreceptor is repeatedly used and discharging by the charger toward the photoreceptor can be stabilized. The advantages contribute to producing small-sized and low-priced image forming apparatus.

A waste toner collection container equipped with a corona charger for use in an electrophotographic arrangement, which includes a waste toner collecting box (11a) for accommodating residual toner scraped off a photosensitive surface of a photosensitive member (10) after transfer, and a corona charger adapted to charge the photosensitive surface of the photosensitive member (10) after charge erasing of the photosensitive surface, with the corona charger being provided on the waste toner collecting box (11a).

Waste toner collecting container provided with corona charger

A process cartridge in which at least a photosensitive member and a corona charger are mounted on a casing made of resin and the corona charger includes a shield casing and a support portion for supporting a discharge wire such that the shield casing and the support portion are molded integrally with the casing, while the corona charger is subjected, substantially at the shield casing, to an electrically conductive coating.

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Nabari, Japan

Yuhi Yui