摘要:
The present invention provides an image forming apparatus which has an image bearing body for bearing a toner image, a transferring member for forming a nip with the image bearing body to pinch a transferring material and for transferring the toner image on the image bearing body to the transferring material, voltage applying device for applying a transfer voltage to the transferring member, voltage detecting device for detecting an applied voltage at which a predetermined current flows through the transferring member before a transferring operation, current detecting device for detecting a current flowing when a voltage based on a detected voltage of the voltage detecting device is applied to the transferring member in a condition where a tip end of the transferring material is present at the nip, and voltage determining device for determining the transfer voltage after the tip end of the transferring material, based on a detected current by the current detecting device.
摘要:
In the conventional types of Active Transfer Voltage Control (ATVC) system, it is assumed that transferring material has definite impedance. When a toner image is transferred to the transferring material which is in a condition where only the top of the transferring material has high impedance, the conventional ATVC system maintains a transferring current higher than the critical transferring current value with the top of the transferring material and applies a bias voltage at a corrected level, whereby the ATVC system may supply an excessive current to a portion of the photosensitive drum corresponding to a location which is other than the top having the high impedance and at which a toner image is not formed. Therefore, it is provided, an image forming apparatus which is capable of favorably transferring a toner image regardless of impedance of a transferring material.
摘要:
In the head-fixing apparatus of the film heating system in an image forming apparatus, a heat capacity is controlled to be as small as possible because the quick-start property is recognized to be more importance. Thus, heat conductivity in the longitudinal direction is poor and, due to a relationship between the area where a recording material is conveyed and the heating area of the energizing heating resistance layer, a) heat is insufficient at the end portion in the initial period and b) unusual temperature rising occurs at the end portion at the time of continuous heat-fixing. In order to resolve those problem, an apparatus which can control adequately temperature at the area where a recording material is conveyed without rising temperature at the end portion of a heater as a non-sheet passing area.
摘要:
In a fixing device, a core material of a fixing rotating member has two largest-diameter portions respectively located between a central portion and each end portion of the fixing rotating member, within a region where a recording material of a largest size passes, and the diameter of each core material is gradually reduced from the largest-diameter portion toward the central portion and toward the nearest end portion. The outer shape of the fixing rotating member conforms to the shape of the core material. According to this configuration, it is possible to prevent corrugation and curl of the recording material, and to provide excellent mountability of the recording material.
摘要:
An image heating apparatus used in an image forming apparatus includes a heating member fixedly disposed, a heat rotary member that slides while an inner surface of the heating member is in contact with the heating member, and a pressure rotary member that forms a heating member and a nip portion through the heating rotary member, in which a recording material that bears an image is nipped between the heating rotary member and the pressure rotary member at the nip portion and conveyed, and the image on the recording material is heated by heat from the heating member through the heating rotary member. In order to obtain a stable heating property (fixing property) not depending on the kind of paper of a recording material (a smooth paper, a rough paper), the temperature of the heating member or the heating rotary member is detected, and the current to the heating member is controlled so that the detected temperature becomes a target temperature. In this situation, the supply power amount to the heating member is monitored, and the target temperature is corrected on the basis of the monitor result. Also, when the temperature detected by the temperature detecting device is within a given range, the current to the heating member is controlled so that a given power is supplied to the heating member.
摘要:
A timer for measuring the image formation interval, and the fixing temperature is set in response to the measured image formation interval so as to balance satisfactorily the degree of fixation, the amount of the recording material curling, and the recording material wrinkling no matter what timing is used to start the next image formation after the completion of the preceding one.
摘要:
An image forming apparatus has an image forming unit for forming an image on a recording material and a fixing unit for fixing the image to the recording material by nipping and conveying the recording material, the fixing unit including a heater which does not generate heat during a standby period in which a printing operation can be started. The heater generates heat for a predetermined period after the start of power supply to the apparatus and then the apparatus is rendered capable of the printing operation.
摘要:
An image fixing apparatus has a heater; a film; and a roller forming a nip with the heater with the film therebetween, the roller being driving to drive the film. A recording material carrying an unfixed image is fed by the nip so that the unfixed image is fixed on the recording material by heat from the heater, and the roller has a surface resin tube layer, wherein the center line average surface roughness Ra (.mu.m), a dynamic friction coefficient .mu., and a peripheral speed of the roller V (mm/sec) satisfy:when Ra 0.3,.mu..gtoreq.1.3.times.10.sup.-3 V+0.18when Ra.gtoreq.0.30.37.gtoreq.Ra.times..mu..gtoreq.6.4.times.10.sup.-4 V+4.8.times.10.sup.-3.The roller's surface resin tube layer includes two different types of resin or resin and rubber materials. The roller's tube layer is subject to electric discharge treatment.
摘要:
An image forming apparatus including an image bearing member for bearing an image thereon, an intermediate transfer member having a base body and an elastic member provided outside the base body and onto which an image is transferrable from the image bearing member, and a second transfer member forming a nip portion between the second transfer member and the intermediate transfer member, for transferring an image from the intermediate transfer member to a transfer material in the nip portion. The hardness of the surface of the second transfer member is greater than the hardness of the surface of the intermediate transfer member.
摘要:
An image heating apparatus includes a rotatable member; back-up means for cooperating with the rotatable member to form a feeding nip for feeding a recording material; heating means for heating an outer peripheral surface of the rotatable member, the heating means including a heater in the form of a plate cooperable with the rotatable member to form a heating nip.