Sharp Kabushiki Kaisha Corporation

Osamu Wakuda

Hiranaga Yamamoto

Hiroyuki Nagao

Hirotaka Toki

Toyoaki Namba

Souichi Takata

Yuji Sugimoto

Yuichi Kazaki

Toshihiro Okahashi

Kenji Okada

Osamu Hashimoto

Tsutomu Sugimoto

Kazuaki Karasuda

A developing unit for visualizing an electrostatic latent image formed on a photoreceptor drum with a toner, includes: a hopper for storing a developer; a developing roller for supplying the toner to a photoreceptor drum on which an electrostatic latent image is formed; and an agitating and conveying portion. In the developing unit, the agitating and conveying portion includes first and second agitating and conveying belts, each having toner agitating blades for agitating and conveying the toner. The first and second agitating and conveying belts are rotatably arranged in the hopper with their rotational axes set approximately vertically so as to rotate the toner agitating blades approximately horizontally.

Developing unit and image forming apparatus using the same

A double-side image forming apparatus forms an image on one side of a sheet in a laser printer section, reverses the leading edge and the trailing edge of the sheet with respect to the transporting direction in a turnaround section, turns over the sheet by moving the sheet through an upper or lower reversing transport path, and transports the sheet to the laser printer section again. A sheet guiding device guides the sheet output from the turnaround section to one of the upper and lower reversing transport paths. When the sheet is again transported to the laser printer section, an image is formed on the other side of the sheets. This configuration simplifies the structure of the apparatus and reduces the size thereof compared to a configuration in which only one reversing transport path capable of holding the same number of sheets therein is formed.

Double-side image forming apparatus and reverse sheet feeding device

A feeding apparatus has a large turntable mounted rotatably on a tray and two paper cassettes installed on the turntable. The paper cassette are movable in a radial direction of rotation of the turntable. Carriage driving mechanisms for moving the paper cassettes are controlled to move the respective paper cassettes to positions closest to the axis of rotation of the turntable when rotating the turntable so that the space occupied by the paper cassettes is minimized. A 180-degree rotation mechanism for rotating the turntable is controlled to rotate the turntable after the respective paper cassettes are moved to the positions closest to the axis of rotation of the turntable, for interchanging the paper cassette on a feeding side and the paper cassette on a non-feeding side. This enables a reduction in the size of the apparatus, irrespective of the sizes and positions of the paper cassettes on the feeding side and non-feeding side.

Feeding apparatus

A large turntable is mounted rotatably on a tray, and two paper cassettes are rotatably installed on the turntable. The turntable is rotated by a 180-degree rotating mechanism and a small angle rotating mechanism, while the paper cassette is rotated by a cassette rotating mechanism. The 180-degree rotating mechanism interchanges the paper cassette on a feeding side and the paper cassette on a non-feeding side by rotating the turntable. The small angle rotating mechanism aligns the center of paper stored in the paper cassette on the feeding side with a feeding center line by rotating the turntable. The cassette rotating mechanism positions the leading edge of the paper in the paper cassette on the feeding side at right angles to a feeding direction by rotating the paper cassette. Since the 180-degree rotating mechanism and the small angle rotating mechanism are installed in positions on the tray outside of the turning space of the turntable, an apparatus of a reduced height and size is achieved.

A carriage driving mechanism moves a paper cassette forward and backward along a feeding direction. A cassette rotating mechanism rotates the paper cassette. A single carriage driving mechanism and a single cassette rotating mechanism are provided for each paper cassette and installed on a level between a cassette circular plate and a large turntable. The carriage driving mechanism includes a driving system constituted by a pulse motor, a series of gears, a pulley, a carriage, a wire wound around the pulley, and guide bars. The cassette rotating mechanism includes a pulse motor and a series of gears. The driving system of the carriage driving mechanism and the cassette rotating mechanism are mounted on the bottom surface of the carriage so as to be level, and move along with the carriage. This configuration enables a reduction in the height and size of a rotatable cassette-type feeding apparatus and an increase in copying functions.

Rotatable cassette type feeding apparatus

A rotatable cassette-type paper feeding apparatus includes a tray, a turning member mounted rotatably on the tray. A first rotating device is used for rotating the turning member, a plurality of paper cassettes installed rotatably on the turning member. A second rotating device is used for rotating the paper cassette in a paper feeding side, and a controller which controls the first rotating device to interchange the paper cassettes in the paper feeding side and in the non-paper-feeding side and which controls the second rotating device to switch the position of the paper cassette in the paper feeding side between sideways and lengthways. This structure achieves a compact rotatable cassette-type paper feeding apparatus capable of storing sheets of paper of various sizes and of feeding the paper sheets both sideways and lengthways by switching their positions.

Rotatable cassette-type paper feeding apparatus

The intermediate tray of a copying machine for copying on both sides of recording paper or recording paper feeding apparatus incorporates a mechanism for loosening and separating recording papers by air blow in order to prevent duplicate feed. Conventionally, such constitution could not be commonly applied to recording papers of plural sizes, and the recording paper vibrated due to the air flow to give off a loud noise. In the invention, the air flow is formed by plural nozzles arranged in the widthwise direction of the recording paper, and the nozzles near the both ends are controlled by opening and closing depending on the paper size. When the recording paper is conveyed by vacuum attracting to the belt, the recording paper is attracted closely to the belt, eliminating the space for allowing the air flow to enter in, so that vibration may be prevented.

Sheet feeding apparatus

When stacking up recording papers on a tray and conveying one by one from the top or bottom, they are conveyed by attracting in vacuum to a conveying belt. An example of conveying from the bottom is illustrated. When one recording paper is conveyed, its rear end comes into the attraction region of the conveying belt, and the second recording paper is attracted into the region out of the first recording paper in the attraction region, which results in duplicate feed. Therefore, the size of the attraction region is variable depending on the size of the recording paper so that the attraction region of the conveying belt may not come out from the rear end of the recording paper until the first recording paper is conveyed and its front end is held by the rear rollers of the conveying belt or the like.

Sheet feeding apparatus that uses a variable vacuum surface and timer to

A sheet feeding apparatus enables the uppermost sheet in sequence in a stack of recording papers be lifted by air flow to separate and to convey the recording paper. The feeding apparatus comprises a laying plate on which plural sheets are stacked, a sheet feeding means disposed above the stacked sheets, which means partially deforms the first sheet in sequence by negative pressure at the leading end part of the sheet, and air forming means which injects air flow between the first sheet and the next sheet near the both ends in the widthwise direction of the recording paper, which flow comprises a straightforward air flow, and an air flow directed outwardly in the widthwise direction. The recording paper is separated from the next sheet by the air flow.

Top sheet feeding apparatus

A feeding device has a rotative threaded shaft and a rotatable paper tray. A movable joint is attached to the rotative threaded shaft, and permitted to move on the shaft. The movable joint is coupled to one corner of the rotatable paper tray. A shaft drive plate is secured to the movable joint. In the vicinity of the rotative threaded shaft, is disposed a shifting shaft extending in the direction of movable joint movements, which is permitted to freely move in the direction. An engaging member to be depressed by engaging the shaft drive plate and a spring to urge the shifting shaft to be located in a predetermined position, are attached to the shifting shaft. On the other hand, in the feeding device main body, there are installed an action plate for making a forward or backward movement in response to a movement of the shifting shaft driven by the shaft drive plate and switch for performing ON/OFF operation in response to shifting positions of the action plate. Thus, this arrangement makes it possible to reduce the number of required parts for connecting the feeding device to the feeding device main body and for detecting operating conditions of the rotatable paper tray.

Growing community of inventors

Yamatotakada, Japan

Osamu Wakuda