Ricoh Company, Ltd.

Epson Toyocom Corporation

Yoshiaki Tanaka

Hiroshi Hosokawa

Iwao Matsumae

Eisaku Murakami

Hiroshi Saitoh

Tetsuo Yamanaka

Toshihiro Sugiyama

Kazuhiro Yuasa

Eiji Takenaka

Satoru Komatsubara

Shuichi Endoh

Mugijiroh Uno

Shigekazu Enoki

Hideaki Mochimaru

Nobuhiro Makita

Masayoshi Miyamoto

Hiroyuki Idenawa

Takeshi Motohashi

Hajime Kanda

Hideo Aoki

Yoshiro Tomikawa

Hiromi Takada

Yasuhiro Sagawa

Takami Suzuki

Tadaaki Kanno

Toshio Shimazaki

Hisao Ishizu

Fumihiro Kitahara

Mugijiro Uno

Takanori Yamaki

Takahiro Yagisita

Tomoo Sankoda

Koyo Hariyama

Eizi Takenaka

Mugiziroh Uno

The present invention provides a piezoelectric vibration gyro-sensor utilizing Coriolis force that includes a tuning fork type vibrator in which two rectangular-columnar arms and a base to support the lower end of the arms are integrated; drive electrodes formed on two rectangular-columnar arms; and IDT electrodes of a surface acoustic wave element formed on two arms. Two pairs of the drive electrodes are provided on each rectangular-columnar arm, in which each of the pairs of drive electrodes face each other, and each pair of the drive electrodes are arranged in parallel on the rectangular-columnar arm at a given distance. The IDT electrodes of the surface acoustic wave element are provided between the drive electrodes at the lower end of the rectangular-columnar arms.

Piezoelectric vibration gyro-sensor

In an image forming apparatus, a developing device operable with toner or single component type developer has a hard first developing roller and a soft second developing roller. Fine magnetic N-S poles are formed on the periphery of the first roller. The second roller conveys the toner, electrostatically transferred thereto from the first roller, to an image carrier. The device frees a toner image from deterioration due to toner particles charged to a polarity opposite to an expected polarity. The toner forms a uniform thin layer on the first roller and is uniformly charged. Toner for use with this type of developing device is also disclosed.

Developing device for an image forming apparatus

A sheet feeding apparatus for use in an image forming system includes a pivoting tray and a pivoting separating member which press against a feed roller. The movement of the tray and separating member is controlled by a cam having a first cam surface which controls the movement of the tray and a second cam surface which controls the movement of the separating member towards and away from a feed roller. The cam includes a gear having a segment without gear teeth. A spring pushes a third cam surface of the cam in order to rotate the cam so that the portion of the gear of the cam having teeth mesh with an idler gear which imposes a rotational force from a motor onto the cam.

Compactly assembled sheet feeding apparatus with a movable paper tray

In an electrophotographic image forming apparatus of the type using single-ingredient type high resistance toner, a developing roller or similar toner conveyor roller is covered with a dielectric layer which is comparatively thick at opposite end portions than at an intermediate portion. A conductive or semiconductive elastic layer underlies the dielectric layer. With the above configuration, the dielectric layer is prevented from coming off the roller. This, coupled with the fact that the elastic layer does not contact a photoconductive element, eliminates current leaks and thereby extends the life of the roller and photoconductive element.

Method of coating a toner conveyor roller

A sheet feeding device for feeding sheets from a tray one by one and an image forming apparatus having the same are disclosed. A tray loaded with a stack of sheets, a separating member for separating a sheet paid out from the tray from the other sheets, and a driven conveyor roller are sequentially arranged around a single pick-up roller. With this arrangement, it is possible to reduce to a load to act on the sheet being conveyed by the pick-up roller and conveyor roller, and to prevent accidental continuous feed or simultaneous feed of a plurality of sheets.

Sheet feeding device and image forming apparatus having the same

In an electrophotographic recording apparatus of the type using a single-ingredient type developer, i.e., toner, a developing device has a developing roller for conveying the toner deposited thereon, and an intermediate roller for conveying the toner transferred theretofrom the developing roller and depositing it on a latent image electrostatically formed on an image carrier to thereby produce a corresponding toner image. During the development of an area of the image carrier other than a latent image area, a bias assigned to the developing roller is switched over to thereby form an electric field different in direction from an electric field assigned to the formation of the toner image between the two rollers. Further, before the rotation of the image carrier is stopped, the bias assigned to the developing roller is again switched in order to form the electric field for the formation of the toner image between the rollers. As a result, a toner layer is formed on the intermediate roller. Subsequently, the rotation of the image carrier is stopped. The device obviates defective images ascribable to the adhesion of the image carrier and intermediate roller while eliminating background contamination and wasteful toner consumption.

Developing device for an electrophotographic recording apparatus

An image forming device which allows reducing a linear velocity ratio of a developing roller against a sensitive body, which enables a pole pitch of a magnetic field generating layer to be miniaturized, and which generates a uniform and adequately thick toner layer on the developing roller. A toner regulating element formed by a sheet metal material having elasticity and non-magnetic characteristics elastically contacts a surface of the developing roller. The developing roller has an elastic body layer and a magnetic field generating layer having a minute pole pitch. The toner regulating elements serves to regulate a thickness of the toner layer without vibration induced from the pole pitch of the magnetic field generating layer. Thus, the toner layer can be uniform and of an adequate thickness, and reducing the linear velocity ratio of the developing roller against the sensitive body does not generate any drawbacks.

Image forming device for forming a uniform toner layer on a developing

In an image forming apparatus using a corona discharge type charging device and a contact type image transferring device, a toner deposited on a photoconductive element in the form of a black stripe is prevented from being transferred to the image transferring device; otherwise, the toner would be transferred from the image transferring device to the rear of the following recording medium. Because the toner forming the black stripe is limited to the toner charged to a polarity opposite to an expected polarity, toner consumption ascribable to the stripe is reduced.

Image forming apparatus with bias control to prevent undesirable toner

An image forming apparatus including a developing device having various components with specific relationships between their lengths. There is an image bearing member such as a photoconductive drum or belt having a photosensitive layer. The photosensitive layer has a length A. A first toner transporting roller has two ends, the length between the two ends being defined as B. Additionally, there is a second toner transporting roller, disposed between and contacting both the image bearing member and the first toner transporting roller. The length of the second toner transporting roller being defined as C. The components of the image forming apparatus are constructed such the length of the second toner transporting roller is less than or equal to the lengths of both the first toner transporting roller and the photosensitive layer of the image bearing member. This means that the relationships A&gt;C and B&gt;C may exist. As an alternative, B is approximately equal to C with A being greater than both B and C. As a further alternative, A, B and C are each approximately equal to each other.

Developing device having the lengths of two toner transporting rollers

A developing apparatus is capable of providing stable charging ability for a developer and stable transfer ability for transferring the developer to a photoreceptor for electronic photography to prevent residual positive images and stain of texture which appear on a toner image. A first toner transfer roller 23 has a core supported to be rotatable and a sheet type insulation layer wound around the outer periphery of the core. The insulation layer is made of elastic rubber in which magnetic material having a specified particle size is uniformly dispersed and the magnetic material is formed with ferromagnetic substance such as magnet and magnetized in advance. The first toner transfer roller 23 attracts toner T by actuating magnetism on the insulation layer since the magnetic material added to the insulation layer is magnetized.

Developing apparatus for electronic photographic recording equipment,

In an image forming apparatus, a developing device has a first developer carrier for depositing a developer thereon, a regulating member for regulating the amount of the developer deposited on the first developer carrier, and a second developer carrier having an elastic surface, and contacting the first developer carrier while biting into it by a predetermined amount. The developer is provided with a preselected degree of fluidity. Hence, even when the same portion of the surface of the second developer carrier runs a plurality of times past a position where the two developer carriers contact each other without any developer being fed from the second developer carrier to an image carrier, the first developer carrier can surely strip the developer from the second developer carrier. As a result, a developer on which a predetermined amount of charge is deposited is transferred from the first developer carrier to the second developer carrier. This successfully protects images from defects. Particularly, when the developer has a zinc stearate content of greater than 0.1 wt %, it is possible to prevent the developer from melting and adhering to a member which regulates the developer.

Device for electrostatically developing a latent image on an image

A developing apparatus includes a toner supporting member for attaching toner to an image supporting member on which an electrostatic latent image is formed so as to develop the electrostatic latent image with the toner supporting member and the image supporting member contacting each other. A toner restricting member forms a toner layer on the toner supporting member uniformly. Further, the toner supporting member has an elastic inner layer and a surface layer on which a magnetic portion is formed, and non-magnetic portions are formed on both end portions of said surface layer. Moreover, a length of the surface layer may be equal to or larger than a length of the inner layer in a longitudinal direction.

Developing apparatus having a toner supporting roller with an inner

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Kawasaki, Japan

Yoshiaki Tanaka