Abstract: There is described an image forming apparatus, wherein a visible image retained on an intermediate transfer belt is collectively transferred to recording material by means of a collective transfer device including a transfer roller and a back-up roller. The recording material that has passed through a transfer nipping region is guided by means of a recording material guide member. In such an image forming apparatus, the intermediate transfer belt is set at an angle of 50.degree. or less relative to the reference line passing through the exit of the transfer nipping region between the transfer roller and the back-up roller among normals orthogonal to a line passing through the center shafts of the transfer roller and the back-up roller, in the area downstream from the transfer nipping region, and the recording material guide member is provided downward at an angle of 5.degree. to 20.degree. relative to the reference line L.

Abstract: An object of the present invention is to provide an image forming apparatus capable of preventing vibration of a transfer film caused from the operation of a separating device to prevent irregular density distribution and change in the hue. The image forming apparatus according to the present invention and having: a transfer-medium holding member having a transfer film for adsorbing and carrying a transfer medium and arranged such that an image is formed on the transfer medium; an internally and upwardly pushing member movably disposed on the surface of the transfer film opposite to the surface to which the transfer medium is adsorbed; a moving device for moving the internally and upwardly pushing member by a predetermined quantity so that the internally and upwardly pushing member upwardly pushes the transfer film to deform the transfer film to separate the transfer medium from the transfer film; and a preventing device for preventing vibration of the internally and upwardly pushing member.

Abstract: An image forming apparatus includes a sheet transport channel including a registration roller for supplying a sheet that is fed from a tray to an image recording section at predetermined timing. A brake forcibly stops rotation of the registration roller. A sensor senses the occurrence of an abnormality in the paper transport channel during transport of the sheet. A controller activates the brake when the sensor has detected the abnormality. Therefore, when a POP jam occurs, sheet rushing into the cleaner due to an overrun can be reliably prevented. Also, in the case of feeding a sheet to prevent a guillotine jam, sheet rushing into the image recording section due to idle rotation of the registration roller can be prevented reliably.

Abstract: An image forming apparatus includes an image carrying body on which a toner image is created. A sheet carrying/transporting rotational body adsorbs a recording sheet to which the toner image on the image carrying body is transferred, and transports the sheet. The recording sheet is detached after transfer from the sheet carrying/transporting rotating body, and an assisting device thrusts against the non-image area of the recording sheet to limit its detachment from the sheet carrying/transporting rotating body. The image forming device can prevent transportation failure and image smudging that is otherwise generated when a thick sheet provided with a curl before it is adsorbed to a sheet carrying/transporting rotational body is detached in the curved state from the rotational body and transported to a fusing means.

Abstract: A developing device which develops an electrostatic latent image formed on an image carrier by toner, thereby forming a toner image; a transferring device which transfers the toner image to a fed transfer material; a registration device which provides a timing of feeding the transfer material; a curling device which nips the transfer material so as to produce a curl which is curved in the same direction as the transferring device; a curling control device which controls a nip operation mechanism of the curling device; and mode setting means for instructing the curling control device to operate are disclosed. In accordance with a thick sheet mode set in the mode setting means, the nip operation of the curling device is executed and a dummy transfer period in which the transfer operation of the transferring device is stopped is set.

Abstract: An image forming apparatus capable of preventing a transfer material detecting unit from making any detection error when the surface of a transfer drum becomes opaque, and restraining transfer film replacement intervals from being shortened with a simple constitution. The image forming apparatus is provided with a transfer material detecting unit for detecting conditions in which a transfer material is conveyed on a transfer material carrier, and a transfer material peeling unit for peeling the transfer material off the transfer material carrier by contacting the surface of the transfer material carrier. At least part of the transfer material peeling unit is disposed so that it at least linearly contacts the axial surface of the transfer material carrier at the same position as that of the transfer material detecting unit in the axial direction of the transfer material carrier.

Abstract: A predetermined sheet retaining plane C for absorbing a record sheet is provided in the circumferential surface of a sheet carrier, and a low-reflectivity area which is to be partially covered with the record sheet is provided at a leading portion of the sheet retaining plane C. Reflection photosensors for detecting the reflectivity of the sheet carrier including the low-reflectivity area are disposed around the sheet carrier. Whether a record sheet is held in the sheet retaining plane C is judged on the basis of detection signals of the photosensors.

Abstract: An image forming apparatus wherein a plurality of toner images having different colors from each other are successively formed on an image carrier, and the plurality of toner images formed on the image carrier are transferred to a transfer member carried on a transfer member carrier in such a condition that the plural toner images are successively overlapped with each other to thereby form an image, characterized in that the image forming apparatus comprises a pawl-shaped stripping member for stripping the transfer member from the transfer member carrier while being made in contact with a surface of the transfer member carrier at a predetermined timing; a volume electric resistance value of at least a portion of the pawl-shaped stripping member, which is made in contact with the transfer member, is selected to be greater than, or equal to 10 .OMEGA..cm, and smaller than, or equal to 10.sup.7 .OMEGA..cm; otherwise a surface electric resistance value thereof is selected to be greater than, or equal to 10 .

Abstract: A transfer material detecting device contains a transfer material carrier that detachably carries a transfer material to transport the transfer material to a transfer region where a toner image of an image carrier is transferred to the transfer material; and transfer material sensors that are disposed in a moving path of the transfer material carrier and detect the existence of the transfer material carried by the transfer material carrier. The device contains at least two transfer material sensors arranged in a moving direction of the transfer material carrier at intervals that are shorter than the minimum size of the transfer material to be detected; and a device for outputting a transfer material detection signal when at least two of the transfer material sensors simultaneously detect the existence of the transfer material.

Abstract: A rear end plate having openings is bonded to a rear end portion of a transfer film through urethane sponge. To attach the rear end portion of the transfer film to a coupling member of a frame of a transfer material carrying body, restricting portions of respective restricting members are fixed to the coupling member through the respective openings of the rear end plate. The restricting portions of the restricting members abut the top face of the rear end plate so as to restrict a radial movement of the rear end plate and allow its circumferential movement.

Abstract: A transfer element detect device which, for use in an image forming apparatus such as a copying machine, a facsimile, a laser printer and the like, can detect accurately whether a transfer element such as copying paper or the like is present at a given position of transfer element attracting means or not. A threshold value is set in accordance with a peak value Pd' on the side of the received light signal level (curved line C) of the received light signal levels (curved line D') of the light sensor when a transfer element is not attracted on transfer element attracting means. After then, in accordance with the thus set threshold value S, it is detected whether the transfer element is present on the transfer element attracting means or not.