Abstract: An image forming apparatus of the present invention includes a conveyance path extending from a sheet tray to an image forming section. A switchback path with a reversing device is connected to the intermediate portion of the conveyance path for switching back a sheet thereon. The switchback path reduces an interval between consecutive sheets being conveyed in the apparatus for thereby enhancing the productivity of image formation. In addition, the switchback path switches back a sheet being conveyed via a refeed path and the above conveyance path in a duplex print mode, thereby obviating the need of an exclusive switchback path for the duplex print mode. The apparatus is reduced in thickness despite the presence of the switchback path.

Abstract: An image forming apparatus including a plurality of image forming cartridges removably mounted to an apparatus body one above the other is disclosed. Structural members each partition off a space between nearby image forming cartridges mounted to the apparatus body. The apparatus is capable of obviating banding ascribable to the vibration of the cartridges.

Abstract: An image formation apparatus has a branching claw with a first guide surface along a side of a sheet to be fed into a reversing path and a second guide surface along a side of a sheet to be fed out of the reversing path. This branching claw is disposed so as to enable switching between a first switching position where the sheet is allowed to be fed into the reversing path through its conveyance along the first guide surface, and a second switching position where the sheet is allowed to be forwarded from the reversing path toward the downstream side of a sheet conveying path through its conveyance along the second guide surface.

Abstract: An image forming apparatus includes a plurality of image formation units which print an image of different color on a paper and also form positional deviation detection marks and image density regulation marks, on a conveyer belt or on at least one of a recording medium and an intermediate transfer body that conveys the paper, when such a request is received. When requests for formation of the positional deviation detection marks and the request for the formation of the image density regulation marks is received at the same time or at substantially the same time, the main CPU orchestrates the conveyer belt and the image forming units to form the positional deviation detection marks and the image density regulation marks in continuation.

Abstract: An image forming apparatus of the present invention includes a printer engine for forming an image on a paper sheet fed from a paper cassette. A paper feeder feeds the paper sheet from the paper cassette to the printer engine while separating it from the other paper sheets stacked on the cassette. A switchback path branches off the transport path of the paper feeder for temporarily storing the paper sheet fed from the paper cassette. The paper sheet fed from the paper cassette enters the switchback path with its leading edge at the head. A roller pair is positioned on the switchback path for switching back the paper sheet received in the switchback path such that the paper sheet leaves the switchback path toward the printer engine with its trailing edge at the head.

Abstract: An image forming apparatus of an electrophotographic type including a paper feeding device for separating and feeding piled recording paper, an image forming device for forming the image in order on the fed recording paper, a paper turning-over device for switching back the recording paper and turning over the front and rear tip ends of the recording paper, and a paper re-feeding device for re-feeding the recording paper having the image on one-side surface. In such an apparatus, the both-surfaces image formation can be practiced at the same paper distance, keeping the image forming apparatus small in size and low cost. Furthermore, a conveying roller for switching back the paper and sending out the paper to a printer engine is provided such that the rear tip end of the paper accommodated in the switching-back path becomes the front tip end thereof, and a jogger for performing compensation of lateral registration for the paper is provided in the switch-back path.

Abstract: An image forming apparatus, particularly a color image forming apparatus, of the present invention distinguishes a register mark and the background of a conveying member on the basis of the level of a signal representative of the background and the peak value or the bottom value of the signal. The apparatus can therefore accurately detect deviation between images of different colors and correct it.

Abstract: An image forming apparatus including a plurality of image forming cartridges removably mounted to an apparatus body one above the other is disclosed. Structural members each partition off a space between nearby image forming cartridges mounted to the apparatus body. The apparatus is capable of obviating banding ascribable to the vibration of the cartridges.

Abstract: An image forming apparatus including a plurality of image forming cartridges removably mounted to an apparatus body one above the other is disclosed. Structural members each partition off a space between nearby image forming cartridges mounted to the apparatus body. The apparatus is capable of obviating banding ascribable to the vibration of the cartridges.

Abstract: The image forming apparatus comprises a plurality of image formation units which print an image of different color on a paper and also form positional deviation detection marks and image density regulation marks, on a conveyer belt that conveys the paper, when a request such a received. When requests for formation of the positional deviation detection marks and the request for the formation of the image density regulation marks is received at the same time or at substantially the same time, the main CPU orchestrate the conveyer belt and the image forming units to form the positional deviation detection marks and the image density regulation marks in continuation.

Abstract: An image forming apparatus including a plurality of image forming cartridges removably mounted to an apparatus body one above the other is disclosed. Structural members each partition off a space between nearby image forming cartridges mounted to the apparatus body. The apparatus is capable of obviating banding ascribable to the vibration of the cartridges.

Abstract: In an image forming apparatus, an image reading device has a first document setting section for setting a document, and a second document setting section included in an ADF (Automatic Document Feeder) which is capable of supporting and processing a document independently of the first document setting section. The second document setting section allows a number of documents to be stacked thereon. A switching device selectively causes either the document of the first document setting section or that of the second document setting section to be read. A control unit interrupts, when a read request requesting a first reading operation using the first document setting section is input while a second reading operation using the second document setting section is under way, the second reading operation, then executes the first reading operation, and then resumes the second reading operation after the first reading operation.

Abstract: The color image forming method of the kind sequentially forming toner images of different colors on an image carrier with developers of corresponding colors stored in a plurality of developing devices, sequentially transferring the toner images to a single paper or similar recording medium one above the other, and returning the toner left on the image carrier after the image transfer to the developing devices color by color, and an image forming apparatus practicable therewith. After the transfer of a toner image of any particular color to the paper wrapped around a transfer drum, a cleaning roller assigned to the above color each collects the toner remaining on the drum and again deposits it on the drum. The drum conveys the redeposited toner to one of the developing devices storing a developer of the same color as the toner.

Abstract: An image forming apparatus includes a cleaning member for collecting toner left on an image carrier after image transfer, and then redepositing it on the carrier, so that a developing unit can collect the redeposited toner to reuse it. Even when the frictional charging ability of the cleaning member falls due to aging or varying environment, the charge of the toner left on the image carrier is regulated to preselected polarity before the toner reaches the cleaning member, thereby enhancing a toner collecting efficiency and a toner redepositing efficiency. The charge of the toner redeposited on the image carrier and moved away from the cleaning member is regulated to preselected polarity while being increased, thereby reducing a load to act on the developing unit. The toner is redeposited on the image carrier efficiently without regard to the polarity of the toner collected by the cleaning member.

Abstract: In an image forming apparatus with an ADF (Automatic Document Feeder), a conveyor mechanism sequentially conveys documents from a document feeding section to a document collecting section by way of a slit for scanning the documents. The feeding section and collecting section are disposed one above the other. The ADF including the feeding section and collecting section can be bodily pulled out toward the operator away from a scanner including a CCD (Charge Coupled Device) image sensor, lens, and light source.

Abstract: A developing unit using a bicomponent developer and capable of collecting only carrier included in the developer and deteriorated due to aging while recycling toner, and a method of collecting the developer from the developing unit. The developing unit separate the developer into toner and carrier before the collection of the developer.

Abstract: In an image forming apparatus, during the course of recording, a cleaning roller is rotated together with an image carrier. The roller frictionally charges toner left on the image carrier after image transfer to the same polarity. A cleaning member electrostatically collects the charged toner. At the same time, a voltage is applied to the cleaning member by a voltage applying device in order to cause it to attract the charged toner, thereby cleaning the image carrier. Hence, even when the toner remaining on image carrier is charged partly to the positive polarity and partly to the negative polarity, the toner can be entirely transferred to the cleaning member by a simple construction.

Abstract: A sheet feeder incorporated in an image forming apparatus and allowing the distance between the preceding sheet and the succeeding sheet to be reduced to a minimum necessary one. A pair of control rollers whose transport speed is controllable are located upstream of an image forming section with respect to an intended direction of sheet transport. An image transfer and paper separation unit is located at the image forming section. The transport speed of the control rollers is made higher than an image forming speed for any desired period of time after the leading edge of a sheet has been gripped by said control rollers and before the leading edge reaches the image forming section. As a result the distance between the preceding and succeeding sheets is reduced to increase the number of images which can be formed for a unit time without the transport speed at the image forming section being increased.

Abstract: In a device for storing printings, film sheets or similar recording media driven out or an image forming apparatus, bins are each inclined from a top sheet inlet thereof to a bottom sheet outlet thereof. When all the bins are full, such a condition is reported to users. Users having left sheets in the trays for a long period of time are alerted by a warning message. Sheets become needless for users can be automatically disposed of by commands from user stations. A user passes an I.D. card through a card reader to enter an I.D. number, opening a bin corresponding to the I.D. number, dropping the sheet onto a fence for user access.

Abstract: A fixing unit protection apparatus and method for protecting a fixing unit in an image forming system against damage. The apparatus includes a first detection part for detecting a fixing temperature of a fixing roller in the fixing unit at which toner is fixed on a copy sheet, the fixing roller being heated by a heater provided within the fixing roller, and a fixing temperature control part for switching ON and OFF current applied to the heater in response to the fixing temperature, so as to prevent the fixing temperature from being an excessively high temperature.