Abstract: A belt driving apparatus which inhibits a belt meandering so as to improve a printing quality and rapidly starts a printing motion at a time of starting the apparatus such as a time of turning on power or the like, and an image forming apparatus using the same. The belt driving apparatus has an endless belt, a plurality of belt tension supports for supporting the belt in a tension manner, and a steering roller supported in a tiltable manner and compensating a meandering of the belt, and the belt driving apparatus is provided with a meandering compensation sensitivity adjuster for adjusting a belt meandering compensation sensitivity of the steering roller per an angle of incline.

Abstract: The invention provides a belt driving apparatus which inhibits a belt meandering so as to improve a printing quality and rapidly starts a printing motion at a time of starting the apparatus such as a time of turning on power or the like, and an image forming apparatus using the same. The belt driving apparatus has an endless belt, a plurality of belt tension supporting means for supporting the belt in a tension manner, and a steering roller supported in a tiltable manner and compensating a meandering of the belt, and the belt driving apparatus is provided with a meandering compensation sensitivity adjusting means for adjusting a belt meandering compensation sensitivity of the steering roller per an angle of incline.

Abstract: In a corona discharging apparatus for use in an electrophotographic printing apparatus, a wire spring-like member having the torque limiter function is used for the cleaning member to conduct the power transmission of the screw shaft, and by releasing the load larger than a predetermined value, the deformation of the gear and deviation of the shaft are eliminated, and the lock of the motor is prevented from being generated.

Abstract: A friction material and a braking device and an image forming apparatus using the friction material. The friction material is formed of polyamide elastomer having a bending modulus of elasticity defined to be in a range of from 100 MPa to 500 MPa.

Abstract: In an image printer performing multi-color printing, two magnetic poles having the same polarity are provided adjacent to each other in a position facing the printing body of the second developing agent holding body provided in the second developing unit, and development is performed under a condition satisfying the following formulas;B1.ltoreq.1100,1000.ltoreq.B2.ltoreq.1200,-300.ltoreq.B1-B2.ltoreq.0,F.apprxeq.0where B1 (gauss) is a magnetic flux density on the surface of the developing agent holding body of one magnetic pole of the magnetic poles arranged in the downstream side of the transmitting direction of the developing agent, and B2 (gauss) is a magnetic flux density on the surface of the developing agent holding body of the other magnetic pole of the magnetic poles arranged in the upstream side of the transmitting direction of the developing agent, and F (gf) is a rubbing force to the printing body of the magnetic brush in the second developing unit.

Abstract: A developing apparatus in which a stationary multipole permanent magnet is placed in a sleeve and in which development is performed by bringing a developer, which contains at least carrier and toner particles and is held on the periphery of a sleeve by use of the magnetic force of the multipole permanent magnet, into contact with a photo-conductive body owing to the rotation of the sleeve. For securing image density and for preventing the deposition of carrier onto the photo-conductive body, two magnetic pieces, each of which is arranged lengthwise in the direction of the axis thereof and which have the same polarity, are placed in a region in the multipole permanent magnet which faces the photo-conductive body in such a manner as to adjoin in the circumferential direction of said permanent magnet. This results in generation of the distribution of a magnetic field which has two peaks of magnetic force.

Abstract: An electrophotographic recording apparatus is provided having a reduced overall size. The space around a photosensitive member required for the developing unit to be located is minimized, more particularly, it i minimized in the lengthwise directional space. In the electrophotographic recording apparatus having a photosensitive member which moves at a predetermined speed; an exposure device for exposing the photosensitive member; a developing unit for developing an electrostatic latent image obtained by the exposure; and a transferring device for transferring a developed visible image to a recording paper sheet or the like, the developing unit is composed of developing devices, a plurality of supporting members for supporting the developing devices and an element for rotating the supporting members.

Abstract: A method of preventing colors from being mixed in a two-color image forming apparatus. The surface of a photoreceptor is uniformly charged. A first latent electrostatic image formed on the photoreceptor surface is developed with a one-component developer so as to form a first toner image. A second latent electrostatic image formed on the photoreceptor surface is developed with a two-component developer so as to form a second toner image. The first and second toner images are simultaneously transferred onto a recording medium. In a preferred embodiment, the one-component developer is a magnetic toner, while the two-component developer is the combination of a nonmagnetic toner and a magnetic carrier. The magnetic toner and the magnetic carrier are preferably powder made of substantially the same materials.

Abstract: An apparatus for printing on opposite surfaces of a strip of printing paper using two electrophotographic printing units wherein each printing operation is of high quality and thermal damage to the printing is minimized. The apparatus includes a first electrophotographic printing unit for printing on the front surface of the printing paper, a buffer unit for temporarily holding the printing paper discharged outside of the first electrophotographic printing unit, a turn unit for turning over the printing paper, and a second electrophotographic printing unit for printing the reverse surface of the printing paper. A toner having a low melting temperature is employed for each of the first and second electrophotographic printing units so that developing treatment is conducted only with the aid of a heat roll but without any use of a preheating plate. A back-up roll adapted to cooperate with the heat roll is coated with a tetrafluoroethylene-based synthetic resin.

Abstract: In a printing sheet conveying device in which a sheet bearing a toner image is passed through a heating roll and a pressure roll, and which has means for changing the right and left contact pressures of these rolls to correct the meandering movement of the sheet when conveyance of the sheet is started; in which when conveyance of the sheet is started, the contact pressure of the rolls is made higher on one of the right and left sides than on the other side, and in a predetermined period of time the contact pressures on both sides are made equal to each other.

Abstract: A laser printer with a thermal fixing unit comprises: a pair of heat and pressure rolls for pressing a sheet with a developed toner image therebetween to fix the toner image on the sheet; a web immersable with an oil; an oil coater for supplying the oil to the web and pressing the web against the heat roll at at least one point to make the web contact with the heat roll so that the oil is applied from the oil coater onto the surface of the heat roll through the web to thereby prevent occurrence of offset of the toner image; and at least one pressing member provided separately from the oil coater for locally urging the web against the heat roll, the pressing member being located on at least one of before and behind the oil coater.