Abstract: A photoreceptor transfers a first image to a first side of a paper, an intermediate transfer belt transfers a second image to a second side of the paper. The intermediate transfer belt also conveys the paper. A conveying unit directly conveys the paper, with the images, to a heating unit that fixes the images. The paper is slowly conveyed in the heating unit as compared to when it is conveyed by the belt.

Abstract: In accordance with the present invention, in an image forming apparatus including a fixing device for fixing a toner image on a sheet with heat at a nip between a fixing member accommodating a heat source and a pressing member not accommodating it, consecutive sheets are driven out of the fixing device at a variable interval without the number of sheets to be output within a preselected period of time being varied.

Abstract: In case a fixing speed is lower than a transferring speed, the individual conveyor units are controlled such that, while a downstream conveyor unit (61) is conveying a sheet (S1) being fixed at the same speed (V2) as the fixing speed, an upstream conveyor unit (60) may convey the succeeding sheet (S2) at the same speed (V1) as the transferring speed. As a result, the spacing of the two sheets in a fixing unit (9) can be sufficiently narrowed to improve the image forming efficiency. Moreover, the transferring speed need not be decelerated according to the fixing speed. It is, therefore, possible to prevent the deterioration in the image quality and to shorten the image forming time period of the first sheet.

Abstract: An image processing apparatus is capable of determining the optimal fixing condition taking the local toner distribution (toner density) into consideration from image data. The toner amount is obtained for a local area formed by a marked pixel and the surrounding pixels per color component signal, and the toner amount of each local area is added. Further, over the image data entirely, the toner amount of local area is worked out in plural local areas. Then, a toner amount that indicates the maximum value is acquired from the toner amount of plural local areas. On the bases of the toner amount in the local area that indicates the maximum value and the kind of sheet on which toner is fixed, the fixing speed is controlled optimally.

Abstract: An image forming apparatus is provided, in which there occurs no pulling of a recording medium at different portions, and also, vibration of a trailing end of the recording medium during the time when the trailing end of the recording medium is passed through the transferring portion is suppressed. Thus, no deterioration occurs in image quality such as disturbance of a toner image.

Abstract: A fixing device for an image forming apparatus of the present invention includes fixing roller and a pressing belt forming a nip therebetween. The fixing belt is passed over a drive roller and a driven roller and formed of a nonconductive material. A charge roller applies a charge opposite in polarity to a toner image carried on a sheet to the pressing belt from the outside surface of the belt. On contacting the pressing belt, the sheet is polarized with the result that a force attracting it toward the pressing belt increases. The sheet is therefore conveyed via the nip while being attracted by the belt 19 and does not or substantially does not wrap around the fixing roller.

Abstract: An image heating apparatus which heats an image on a recording material by holding and conveying the image-borne recording material at a nip between heating and pressure members has a sequence to set a heating temperature of the apparatus to be lower than an ordinary set temperature when, after the recording material of a width narrower than a predetermined width was passed, the recording material of a width wider than that width is passed. The set heating temperature when the wide-width recording material is passed after the narrow-width recording material was passed is controlled according to the number of the passed narrow-width recording materials and an elapsed time from the passing of the narrow-width recording material to the passing of the wide-width recording material, whereby hot off-set occurring when the large size recording material is passed after the small size recording material was passed is prevented without deteriorating fixability.

Abstract: An image forming apparatus is provided with a heating device, a conveying device, and a control device, wherein the control device has a mode for changing the set temperature from a first temperature to a second temperature higher than the first temperature when the leading edge of the recording material passes through the nip portion by a predetermined distance and the predetermined distance is equal to a value 0.3 to 2.0 times larger than the distance between the nip portion and the carrying device. Thereby, a recording-material jam is controlled and the image quality is prevented from deteriorating.

Abstract: An image forming apparatus includes an image forming device for forming an unfixed image on a recording material transported thereto, the image forming device being capable of continuously effecting image formation on recording materials differing in the width thereof in a direction orthogonal to the transport direction thereof, a fixing device having a heat member and for fixing the unfixed image by the use of heat and pressure, and a recording material changeover device capable, when images are to be continuously formed on recording materials smaller in the width thereof in the direction orthogonal to the transport direction than a maximum width with which the recording materials can be passed, of changing over the recording materials to recording materials greater in the width thereof in the direction orthogonal to the transport direction than the recording materials on which images are being formed in the course of continuous image formation.

Abstract: A fixing apparatus comprises a fixing belt held by and wound around a heating roller and a fixing roller, a pressurizing roller held pressed against the fixing roller by way of the fixing belt so as to heat and put pressure on the toner image on a sheet of paper with the fixing roller, a releasing member that releases the sheet of paper adhering to the fixing belt from the fixing belt during the fixing process, and a guide body that guides the sheet of paper along the fixing belt and causes the sheet to stick to and be conveyed by the transfer belt, without being released by the releasing member, along the fixing belt, so as to release the sheet of paper at a position where the fixing belt is held by the heating roller with a small radius of curvature.

Abstract: The image forming apparatus includes a rotatable first rotary member, a rotatable second rotary member brought into pressure contact with the first rotary member, and forming a nip part for nipping and conveying a recording material, first recording material detecting means located at the vicinity of the nip part downstream of the nip part with respect tot he conveying direction of the recording material for detecting the passage of the recording material, drive means for rotatively driving the first rotary member, brake means for applying the brakes to the rotation of the first rotary member, and control means for controlling the brake means, and during jam near the first rotary member, the driving of the drive means is stopped and the control means makes the brakes by the brake means great. Thereby, the amount of wrapping during the wrapping jam of the recording material around the fixing rotary member can be made small.

Abstract: An image forming apparatus of the present invention includes an intermediate image transfer belt to which a toner image is to be transferred from an image carrier, an image transferring device for transferring the toner image from the intermediate image transfer belt to a sheet, and a fixing device for fixing the toner image on the sheet. When the length of the sheet in the direction of conveyance is smaller than a distance between the image transferring device and the fixing device, a matching circuit varies only the speeds of the image transferring device and fixing device, but does not vary the speed of a device that executes a step preceding the image transfer step. The matching device then sets an interval between consecutive sheets matching with the varied speeds of the image transferring device and fixing device, thereby matching opposite sides with respect to the image transfer step to each other as to the number of sheets to be conveyed.

Abstract: A method of controlling a fuser having a heating member and a pressure member wherein the pressure member temperature is estimated from parameters set by a print engine and measured media throughput. Media throughput is used to determine a predicted pressure member steady state temperature (SST) associated with the operating mode of the fuser. The predicted pressure member SST and an estimated pressure member starting temperature are used to calculate a pressure member temperature change, and the calculated temperature change is used to determine an estimated pressure member temperature. The print engine compares the estimated pressure member temperature to a predetermined temperature and reduces the heating member set point temperature if the predetermined temperature is exceeded to avoid the pressure member reaching a maximum temperature.

Abstract: An image recording apparatus includes an image forming section, a transportbelt, a fixing roller, a discharge roller, and a controller. The image forming section forms a toner image on a print paper. The transport belt transports the print paper onto which the toner image has been transferred. The fixing roller is disposed downstream of the transport belt with respect to a direction of travel of the print paper, and then cooperates with the discharge roller to further advance the paper toward the stacker. The controller controls the speeds of the transport belt, the fixing roller, and discharge roller. The speed of the fixing roller and discharge roller are changed relative to the speed of the transport belt in accordance with a distance from a reference position over which the print paper advanced by the fixing roller and discharge roller toward the paper stacker.

Abstract: Electrophotographic imaging methods include providing a fusing device operationally characterized by a fusing speed, a fusing temperature, and a fusing pressure. The fusing speed is controlled as a function of the fusing temperature, while the fusing pressure is controlled as a function of the fusing speed, and the fusing temperature is controlled as a function of the fusing speed and the fusing pressure.

Abstract: An image forming apparatus has an image forming unit and a film-heat-type fuser over which a sheet with an unfixed toner image passes and on which are positioned a first temperature-measuring device centered on the fuser so that a sheet always passes over that device and a second temperature measuring device disposed away from the center so that large sheets will pass over the second temperature measuring device and small sheets will not pass over the device when being conveyed correctly. The device also has a temperature control mechanism, a sheet size detector and throughput control, so that the throughput control changes throughput when the sheet size detector determines that a small sheet is being conveyed and the difference between the temperatures of the first and second temperature measuring devices is less than a predetermined value as the sheet passes over the fuser.

Abstract: An image generating apparatus is provided which can maximize the throughput without causing thermal damage of the fusing components. It determines a sub-thermistor temperature threshold value for switching small size paper feed intervals in response to a sub-thermistor initial temperature. It supplies a heating body with current for heating, and starts feeding recording mediums at the feed interval determined by a feed interval initial value. It makes a successively conveyed paper count. Every time the successively conveyed paper count reaches a paper count threshold value, it performs the switching control of the sub-thermistor temperature threshold value. If the sub-thermistor temperature exceeds the threshold value while the recording medium is passing through the fusing apparatus, it carries out the switching control of the feed intervals. In another mode, it prevents the extension of the paper feed interval of the paper conveyance during a specified paper count &agr;.

Abstract: Disclosed is an image fixing apparatus for use in an image forming apparatus for forming an image on a recording medium. During a process of continuously forming an image on a plurality of recording media, the recording medium feeding speed is switched when the temperature of a fixing roller has dropped to a particular value which is set depending on the rate at which the temperature of the fixing roller drops.

Abstract: An image forming apparatus includes a main body including a sheet transport path having an output part and an image forming part for forming an image on a sheet, and a sheet discharging device located in the vicinity of the output part, and a sheet receiving part. The sheet discharging device discharges the sheet having an image formed thereon by the image forming part. The sheet receiving part receives the sheet discharged by the sheet discharging device. The sheet discharging device includes a discharging member, disposed in the vicinity of the output part, for transporting the sheet in a nipping manner, a drive force transmitting mechanism for driving the discharging member to rotate, and a discharge control unit for controlling the drive force transmitting mechanism when the sheet passes the discharging member so as to temporarily delay a time taken for sheet discharging by the discharging member.

Abstract: It is to provide an image forming apparatus capable of reducing a processing time and of forming an image without high-temperature offset and defect of fixing when images are continuously formed. The image forming apparatus has number of sheets storing means for storing the number of passing sheets upon previous continuous-image-formation; counter means for counting a passing time from the end time of the continuous image formation; and a CPU for, when the images are continuously formed at this time, limiting the number of sheets image-formed at a first copying speed at which the number of sheets is large per unit time to a predetermined number of sheets, based on the number of recorded sheets and the passing time upon the previous continuous-image-formation and for, when the number of sheets is over the limited number of sheets, changing the first copying speed to the second copying speed at which the number of sheets per unit time is small.

Abstract: Electrophotographic imaging methods include providing a fusing device operationally characterized by a fusing speed, a fusing temperature, and a fusing pressure. The fusing speed is controlled as a function of the fusing temperature, while the fusing pressure is controlled as a function of the fusing speed, and the fusing temperature is controlled as a function of the fusing speed and the fusing pressure.

Abstract: In one non-limiting embodiment an apparatus for controlling a fuser in an imaging apparatus includes a first fuser roller and a second fuser roller in parallel, adjacent orientation and configured to receive sheet media therebetween. The apparatus further includes an electrical voltage source applied across the fuser rollers. The apparatus also includes a voltage difference measuring device configured to measure a difference in the electrical voltage across the first and second fuser rollers when sheet media is received between the first and second fuser rollers, and to generate a voltage difference signal in response thereto. The device includes a controller which is configured to receive the voltage difference signal and to generate a fuser parameter control signal in response thereto. The apparatus also includes a fuser control device responsive to the fuser parameter control signal.

Abstract: An image forming apparatus having a fixing apparatus for nipping a recording material bearing an unfixed toner image on the surface thereof by a nip portion between a fixing member and a pressure member and fixing the unfixed toner image on the surface of the recording material has a first temperature detecting element and a second temperature detecting element for detecting the temperatures of the fixing member and the pressure member, respectively, and electric power supplied to a heating portion for heating the fixing member is controlled in conformity with the detected temperature by the first temperature detecting element. When image forming on a plurality of recording materials is to be continuously effected, the conveyance interval of the recording materials is controlled so as to become short when the detected temperature of the pressure member is high, and to become long when the detected temperature of the pressure member is low.

Abstract: An image-forming method for fixing a toner image onto a recording medium, (i) wherein when a high-gloss recording medium (G0>40) is used, an image is formed at a low-speed mode process speed of from 20 mm/sec. to less than 130 mm/sec. and, where the maximum and minimum gloss values of the fixed image (Gmax1 and Gmin1, respectively), satisfy: Gmax1≦G0+40 and Gmin1≧G0−25; and (ii) wherein when a low-gloss recording medium (0≦G0≦40) is used, an image is formed at a high-speed mode process speed of from 130 mm/sec. to 600 mm/sec. and, where values of the fixed image (Gmax2 and Gmin2, respectively), satisfy: Gmax2≦G0+20 and Gmin2≧G0−15.

Abstract: An imaging device is provided that generates and transfers an image to a print media. A fuser fuses the image to the print media through a process of heat and pressure. The fuser is charged with a voltage to reduce toner particles from being attached to the fuser. When the print media contacts the fuser, its current path is altered causing the voltage of the fuser to change. A fuser sensor measures the voltage of the fuser and based on the measured voltage, the imaging device can determine whether a print media is in the fuser. In the event of a malfunction such as a paper jam, the device can determine the location of the paper at least in part by the measured fuser voltage.

Abstract: An image forming apparatus is provided which is capable of positively preventing a recording sheet from being wound around a conveying means that conveys the recording sheet. A high voltage power supply section applies voltage to feeding brushes disposed in contact with the surface of a pressurizing roller having an electrically conductive surface. A winding sensor is disposed in contact with the surface of the pressurizing roller and is located in a sheet passing area of the pressurizing roller. A CPU sets a threshold voltage to a value corresponding to the temperature of the pressurizing roller detected by a temperature sensor, and detects whether the recording sheet is wound around the pressurizing roller, based upon the set threshold voltage and voltage of the pressurizing roller in the sheet passing area detected by the winding sensor.

Abstract: The image heating apparatus has a heating body, an endless belt moving in contact with the heating body, a pressing member forming a nip for nipping and conveying a recording material in cooperation with the endless belt, detecting device for optically detecting the mark portion of the endless belt, control device for controlling a driving speed of the endless belt, based on output of the detecting device, and an electroconductive cleaning member for cleaning the mark portion. In the image heating apparatus, the endless belt has a mark portion.

Abstract: An image forming apparatus has a fixing unit and a control for controlling a peripheral speed of a fixing rotatable member, the following formula being satisfied: Pmin>Lmin 0<X≦&dgr;L/Pmax V0: the peripheral speed; Vf: a feeding speed; Lmin: a minimum path length between a transfer nip and a fixing nip; Lmax: a maximum guide path length between the transfer nip and the fixing nip; &dgr;L=Lmax−Lmin: an amount of loop: Pmax: a maximum length of the transfer material on which toner image may be formed; Pmin: a minimum length of the transfer material on which the toner image may be formed; X: a fluctuation rate of the feeding speed Vf during control of the peripheral speed.

Abstract: An image formation apparatus includes: an image formation unit for forming toner images on a photosensitive drum; a transfer belt for transporting sheets of a transfer medium; an electrostatic transfer unit transferring toner images on the photosensitive drum onto the sheets; a cleaning unit for cleaning residual matter including toner form the photosensitive drum; a charger for applying a bias of a polarity which is inverse to a normal polarity of the toner, to the transfer unit; and a control unit for controlling operations of the charger. The control unit controls the charger such that a transfer bias is applied in sheet spacing between consecutive sheets, so that there is no flow of current to edge portions at the leading and trailing edges of the sheets, that sheet spacing transfer off time is one photosensitive drum cycle or less, that the transfer bias current is set to zero within leading and trailing sheet margins, and that the image is transferred onto the transfer medium in an image region.

Abstract: An image forming apparatus includes a photosensitive member, a transfer mechanism, a fixing mechanism, a sheet ejection mechanism, and a driving source. The transfer mechanism including a transfer roller that transfers a toner image carried on a photosensitive member onto a recording sheet. The fixing mechanism fixes the toner image onto the recording sheet with heat and pressure. The fixing mechanism includes a fixing roller and a pressure plate, and applies heat and pressure to the toner image on the recording sheet when the recording sheet is caused to pass through a fixing nip portion. The sheet ejection mechanism ejects the recording sheet and includes sheet ejection rollers. The driving source drives the photosensitive member, the transfer roller, the fixing roller, and the sheet ejection rollers to transfer the recording sheet at a linear speed in a substantially constant manner from the photosensitive member through to the sheet ejection mechanism.

Abstract: When the paper size signal indicates small-sized paper, after the final sheet of a consecutive sheet feed operation of that size has passed through the heating device, paired rollers consisting of heat and pressing rollers are actuated to rotate for a predetermined period (rotational mode) while no sheet passes therethrough. After completion of the rotational mode, the paired rollers are stopped from rotating for a predetermined period (stationary mode).

Abstract: An image processing apparatus is capable of determining the optimal fixing condition taking the local toner distribution (toner density) into consideration from image data. The toner amount is obtained for a local area formed by a marked pixel and the surrounding pixels per color component signal, and the toner amount of each local area is added. Further, over the image data entirely, the toner amount of local area is worked out in plural local areas. Then, a toner amount that indicates the maximum value is acquired from the toner amount of plural local areas. On the bases of the toner amount in the local area that indicates the maximum value and the kind of sheet on which toner is fixed, the fixing speed is controlled optimally.

Abstract: In case a fixing speed is lower than a transferring speed, the individual conveyor units are controlled such that, while a downstream conveyor unit (61) is conveying a sheet (S1) being fixed at the same speed (V2) as the fixing speed, an upstream conveyor unit (60) may convey the succeeding sheet (S2) at the same speed (V1) as the transferring speed. As a result, the spacing of the two sheets in a fixing unit (9) can be sufficiently narrowed to improve the image forming efficiency. Moreover, the transferring speed need not be decelerated according to the fixing speed. It is, therefore, possible to prevent the deterioration in the image quality and to shorten the image forming time period of the first sheet.

Abstract: A fixing apparatus comprises a fixing belt held by and wound around a heating roller and a fixing roller, a pressurizing roller held pressed against the fixing roller by way of the fixing belt so as to heat and put pressure on the toner image on a sheet of paper with the fixing roller, a releasing member that releases the sheet of paper adhering to the fixing belt from the fixing belt during the fixing process, and a guide body that guides the sheet of paper along the fixing belt and causes the sheet to stick to and be conveyed by the transfer belt, without being released by the releasing member, along the fixing belt, so as to release the sheet of paper at a position where the fixing belt is held by the heating roller with a small radius of curvature.

Abstract: An image forming apparatus of the present invention includes an intermediate image transfer belt to which a toner image is to be transferred from an image carrier, an image transferring device for transferring the toner image from the intermediate image transfer belt to a sheet, and a fixing device for fixing the toner image on the sheet. When the length of the sheet in the direction of conveyance is smaller than a distance between the image transferring device and the fixing device, a matching circuit varies only the speeds of the image transferring device and fixing device, but does not vary the speed of a device that executes a step preceding the image transfer step. The matching device then sets an interval between consecutive sheets matching with the varied speeds of the image transferring device and fixing device, thereby matching opposite sides with respect to the image transfer step to each other as to the number of sheets to be conveyed.

Abstract: It is to provide an image forming apparatus capable of reducing a processing time and of forming an image without high-temperature offset and defect of fixing when images are continuously formed. The image forming apparatus has number of sheets storing means for storing the number of passing sheets upon previous continuous-image-formation; counter means for counting a passing time from the end time of the continuous image formation; and a CPU for, when the images are continuously formed at this time, limiting the number of sheets image-formed at a first copying speed at which the number of sheets is large per unit time to a predetermined number of sheets, based on the number of recorded sheets and the passing time upon the previous continuous-image-formation and for, when the number of sheets is over the limited number of sheets, changing the first copying speed to the second copying speed at which the number of sheets per unit time is small.

Abstract: In an image-forming method having a fixing step of fixing a toner image onto a recording medium, and having at least a low-speed mode and a high-speed mode so as to be able to form images at different speeds;

Abstract: An image forming apparatus is provided, in which there occurs no pulling of a recording medium at different portions, and also, vibration of a trailing end of the recording medium during the time when the trailing end of the recording medium is passed through the transferring portion is suppressed. Thus, no deterioration occurs in image quality such as disturbance of a toner image.

Abstract: An imaging device is provided that generates and transfers an image to a print media. A fuser fuses the image to the print media through a process of heat and pressure. The fuser is charged with a voltage to reduce toner particles from being attached to the fuser. When the print media contacts the fuser, its current path is altered causing the voltage of the fuser to change. A fuser sensor measures the voltage of the fuser and based on the measured voltage, the imaging device can determine whether a print media is in the fuser. In the event of a malfunction such as a paper jam, the device can determine the location of the paper at least in part by the measured fuser voltage.

Abstract: An image fixing apparatus in which a fixing belt is trained about a plurality of support rollers including therein one support roller housing a heat applying source, and a relative position of a pair of pressure rollers is changed, which are oppositely arranged with the fixing belt interposed between them, to a pressure position, a traveling path of the fixing belt is changed, and through the fixing belt whose path is changed, the heat applying source and the support roller housing the heat applying source are integrally movable.

Abstract: The image-forming device includes a fixing device for fixing a toner visible image transferred to a transfer sheet, a feeding device for feeding and conveying the transfer sheet to the fixing device, a cooling fan discharging a heat generated in the fixing device, a conveyance position detecting device for detecting a conveyance position of the transfer sheet being conveyed, and a controlling device for controlling the cooling fan to start and stop revolving according to the conveyance position.

Abstract: An image forming apparatus includes an image bearing body. A transferring portion transfers an unfixed image in the image bearing body onto a recording material, while conveying the recording material. A fixing portion fixes the unfixed image onto the recording material, while conveying the recording material having the unfixed image is transferred in the transferring portion. A flexure detecting device detects flexure of the recording material between the transferring portion and the fixing portion. A recording material detecting device detects the presence/absence of the recording material at a downstream side of the fixing portion with respect to a conveying direction of the recording material. A control device controls a convey velocity of the recording material in the fixing portion on the basis of a time from the detection of the recording material detected by the recording material detecting device to the detection of the flexure of the recording material detected by the flexure detecting device.

Abstract: An image-forming apparatus is disclosed in which, using a photosensitive member and a toner, an unfixed image of the toner is formed on a transfer medium and the unfixed image on the transfer medium is fixed by a heat-and-pressure fixing means. In the image-forming apparatus, a delivery guide member, which guides the delivery of the transfer medium and is placed close to the heat and pressure fixing means, has a value of triboelectric voltage not greater than 500 V as measured by the triboelectric voltage measuring method according to JIS L1094B.

Abstract: The present invention relates to a method for improving a print quality of an image forming apparatus. The invention provides a method for improving the print quality of an image forming apparatus capable of preventing the deterioration of the print image according to the change of the environment condition around the image forming apparatus by controlling the print speed of the image forming apparatus in case that the environment condition is at a low temperature and low humidity when checked at the non-image stage of the apparatus. According to the present invention, it is checked whether or not the environment condition around the image forming apparatus is at a low temperature and low humidity at a non-image period prior to the beginning of print after the print data received externally are stored at a memory of the image forming apparatus.

Abstract: An image forming apparatus of the present invention includes a thermal fixing unit and is capable of varying a sheet conveying speed. The sheet conveying speed is varied in accordance with a resolution selected. The target fixing temperature of the fixing unit is variable in accordance with the sheet conveying speed. Further, the stand-by temperature of the fixing unit after image formation is set in accordance with the resolution selected to thereby control a temperature. This successfully reduces the operator's waiting time and applies adequate heat to a sheet.

Abstract: An option fixing device which is detachably coupled to an image forming apparatus of the type in which a toner image formed on a surface of a photosensitive member is transferred onto a recording sheet is provided. The option fixing device includes a sheet entrance port, a first sheet transport path which receives a recording sheet coming through the sheet entrance port and discharges the recording sheet without passing the recording sheet through a fixing unit, a second sheet transport path which causes the recording sheet to pass through the fixing unit and then discharges the recording sheet, and the fixing unit for fusing and fixing a toner image on the recording sheet being transported on and along the second sheet transport path.

Abstract: An image forming apparatus has an image forming unit and a film-heat-type fuser over which a sheet with an unfixed toner image passes and on which are positioned a first temperature-measuring device centered on the fuser so that a sheet always passes over that device and a second temperature measuring device disposed away from the center so that large sheets will pass over the second temperature measuring device and small sheets will not pass over the device when being conveyed correctly. The device also has a temperature control mechanism, a sheet size detector and throughput control, so that the throughput control changes throughput when the sheet size detector determines that a small sheet is being conveyed and the difference between the temperatures of the first and second temperature measuring devices is less than a predetermined value as the sheet passes over the fuser.

Abstract: An image forming apparatus of the present invention includes two temperature sensors each being responsive to the surface temperature of a particular portion of a fixing member. A reference temperature setting section sets a reference temperature value on the basis of the temperatures that are sensed by the two temperature sensors when the surface of the heating member is heated to a preselected temperature by a heat source. A controller calculates an actual temperature value on the basis of the temperatures sensed by the temperature sensors. The controller then compares the actual temperature value and reference temperature value to thereby determine whether or not a jam ascribable to a recording medium wrapped around the fixing member has occurred. The controller interrupts current supply to the heat source if such a jam has occurred.

Abstract: Paper jams and damage to a printing medium resulting from movement of a print head carriage are prevented in a printing apparatus in which the print head unit moves orthogonally to the direction in which the printing medium, which may be slip form, is transported through a transportation path to the printing unit for printing. A pair of transportation rollers are supported on opposing sides of the transportation path in a manner enabling the transportation rollers to close and open. The transportation rollers are closed to hold and transport the slip form in the transportation path to the printing unit. A driver is controlled to open and close the transportation rollers according to a control command. When a non-print control command involving print head movement is received, the driver is controlled to close the transportation rollers.

Abstract: The present invention provides a fixing apparatus which has a fixing member for fixing an unfixed image onto a recording material, releasing agent applying device for applying a releasing agent to the fixing member, temperature detecting device for detecting a temperature of the releasing agent, and control device for controlling a fixing condition based on a detected temperature from the temperature detecting device.