JP5063386B2 - Heating device - Google Patents

Description

  The present invention relates to a heating apparatus suitable for use as an image heating and fixing apparatus of an image forming apparatus such as an electrophotographic printer or copying machine. More specifically, the present invention relates to an external heating method / heating member sliding contact type heating device.

  In the image forming apparatus, the image forming apparatus is a heating apparatus for heating and fixing an unfixed developer image formed and supported on a recording material by an appropriate image forming process means such as an electrophotographic process as a fixed image on the recording material surface. The fixing device will be described as an example.

  An external heating type fixing device is proposed in Patent Document 1, for example. In this external heating type fixing device, a heating member (heating element) for heating the fixing roller for heating the recording material is provided outside the fixing roller, and the fixing roller is heated from the surface side to a predetermined fixing temperature. Device.

  The external heating type fixing device heats the surface of the fixing roller directly compared with the method of heating the fixing roller from the inside, so that the time until the temperature of the fixing roller rises to a desired temperature is shortened and unnecessary portions are removed. Energy consumption can be reduced.

  There are two types of external heating methods as described above. The first is a contact heating method in which a heating member is brought into contact with the surface of the fixing roller and heated. The second is a non-contact heating method in which a halogen heater or the like is used as the heating member, and the heating member is heated by copying heat without contacting the surface of the fixing roller.

  Since the contact heating method transfers heat directly from the heating member to the surface of the fixing roller, the thermal resistance between the heating member and the surface of the fixing roller is lower and heat transfer efficiency is higher than in the non-contact heating method.

  In the case of the contact heating method, a configuration in which a sliding member is interposed between the heating member and the fixing roller is often employed for the purpose of smoothly rotating the fixing roller.

  In this case, the sliding member is fixed and the fixing roller and the sliding member are slid (sliding type), and the sliding member is not slid with the fixing roller and is rotated with the surface of the fixing roller (sliding type). It is divided into a driven type). The sliding type (fixed type) has many advantages from the viewpoint of efficiency of heat transfer and simplification of the configuration.

In order to further improve the sliding heat transfer efficiency, a configuration is adopted in which a sliding member serving as a thermal resistance is eliminated and the heating member is brought into direct contact with the surface of the fixing roller without using the sliding member.
JP 2003-186327 A

  However, in the case of the sliding-type external heating method described above, dirt such as toner transferred (offset) from the recording material carrying the image to be fixed to the surface of the fixing roller is heated at the contact portion between the fixing roller and the heating member. There is a problem that it tends to accumulate in the nip portion.

  The accumulated lump of dirt that has accumulated has been unexpectedly discharged to the surface of the fixing roller, causing a problem such as fouling the recording material during the toner image heating process.

  Further, when foreign matter enters the heating nip portion, there is a problem that the foreign matter gets caught in the heating nip portion and damages the surface of the fixing roller. If a flaw is generated on the surface of the fixing roller, the flaw is transferred onto the toner when fixing the toner on the recording material, and depending on the depth and width of the flaw, there is a problem of an image defect that looks like a vertical stripe. there were.

  The present invention has been made in view of such technical problems. The purpose of the present invention is to provide a heating device that can collect dirt accumulated in the heating member and remove foreign matter that has entered the heating nip portion of an external heating method / heating member sliding contact type heating device. is there.

  A representative configuration of a heating device according to the present invention for solving the above-described problems includes a rotating member and a heating member that forms a rotating member heating nip portion that contacts the surface of the rotating member and externally heats the rotating member. And a heating device that heats the heated body by bringing the heated body into contact with the heated surface of the rotating body, and in an arbitrary surface on the surface that contacts the rotating body of the heating member in the rotating body heating nip portion Heating member moving means for moving the heating member so that the two points have different velocity vectors is provided.

  According to the present invention, in the sliding contact type external heating device, when the heating member is operated so that arbitrary two points on the surface of the heating member heating nip of the heating member have different velocity vectors, Different frictional forces are generated at each point of the section. Therefore, the foreign matter can be effectively discharged out of the rotator heating nip, and the foreign matter can be prevented from being scratched in one direction with the rotator. At the same time, the dirt that has entered the rotating body heating nip and the dirt that has adhered to the heating nip can be effectively recovered with different frictional forces at each point in the rotating body heating nip.

[Example 1]
A first embodiment of the present invention will be described below. First, the main body configuration of the image forming apparatus in the present embodiment will be described, and then the fixing device as a heating device according to the present invention will be described in detail.

(1) Main Body Configuration of Image Forming Apparatus FIG. 15 is a schematic configuration diagram of the image forming apparatus in this embodiment. This image forming apparatus is a four-color full-color laser printer using an electrophotographic process, and is based on an electrical image signal input from an external device 300 such as a personal computer or image reader to the control circuit unit 200. To form a full-color image. That is, electrical image information of color image information that has been color-separated into three primary colors of RGB (red, green, and blue) is input from the external device 300 to the control circuit unit 200. The control circuit unit 200 is a control unit that performs overall control of the image forming apparatus. The control circuit unit 200 transmits and receives electrical signals to and from the external apparatus 300, and transmits and receives electrical signals to and from various process devices of the image forming mechanism unit. Take control.

  UY, UM, UC, and UK are first to fourth image forming units (image forming stations) arranged in the image forming apparatus in the horizontal direction in order from the right side to the left side in the drawing. The first image forming unit UY forms a yellow (Y color) toner image. The second image forming unit UM forms a magenta (M color) toner image. The third image forming unit UC forms a cyan (C color) toner image. The fourth image forming unit UK forms a black (K color) toner image.

  Each of the image forming units UY, UM, UC, and UK has a drum-type electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) 1 that is an image carrier. The image forming apparatus includes a charger (charging roller) 2 as a process unit that acts on the photosensitive drum 1, a laser scanner 3 as an image exposure device, a developing device 4, a transfer device (transfer roller) 5, and a drum cleaner 6. The developing device 4 of the first image forming unit UY contains Y color toner as a developer. The developing device 4 of the second image forming unit UM contains M-color toner as a developer. The developing device 4 of the third image forming unit UC contains C toner as a developer. The developing device 4 of the fourth image forming unit UK contains K toner as a developer.

  In each of the image forming units UY, UM, UC, and UK, the photosensitive drum 1, the charging device 2, the developing device 4, and the drum cleaner 6 are collectively removed from the main body of the image forming apparatus and are process cartridges PK, PM, and detachable. PC / PK.

  A recording material conveyance belt mechanism 7 is disposed below the four image forming units UY, UM, UC, and UK. The belt mechanism 7 includes an endless recording material conveying belt 8, a driving roller 9 and a tension roller 10 that suspends the belt 8. The lower surfaces of the photosensitive drums 1 of the image forming units UY, UM, UC, and UK are in contact with the upper surface of the ascending belt portion between the driving roller 9 and the tension roller 10. In addition, four transfer units 5 are disposed inside the belt 8 so as to face the photosensitive drums 1 of the image forming units UY, UM, UC, and UK via an ascending belt portion. The contact nip portion between the photosensitive drum 1 and the belt 8 in each of the image forming portions UY, UM, UC, and UK is a transfer nip portion T in each image forming portion.

  The operation for forming a full-color image is as follows. The control circuit unit 200 executes predetermined image formation sequence control based on the image formation start signal. In each of the image forming units UY, UM, UC, and UK, the photosensitive drum 1 is rotationally driven in a clockwise direction indicated by an arrow at a predetermined control speed (process speed). The belt 8 is also rotationally driven in a counterclockwise direction indicated by an arrow (forward direction with respect to the rotation of the photosensitive drum 1) at a speed corresponding to the speed of the photosensitive drum 1. Each laser scanner 3 is also driven. In synchronism with this drive, the charger 2 uniformly charges the surface of the photosensitive drum 1 to a predetermined polarity and potential at a predetermined control timing in each of the image forming units UY, UM, UC, and UK (charging process). . In this example, each photosensitive drum 1 is uniformly charged to a predetermined negative potential. A Y color component image signal of a full color image is output from the control circuit unit 200 to the laser scanner 3 of the first image forming unit UY at a predetermined control timing. An M color component image signal of a full-color image is output from the control circuit unit 200 to the laser scanner 3 of the second image forming unit UM at a predetermined control timing. A C color component image signal of a full-color image is output from the control circuit unit 200 to the laser scanner 3 of the third image forming unit UC at a predetermined control timing. A K color component image signal of a full color image is output from the control circuit unit 200 to the laser scanner 3 of the fourth image forming unit UK at a predetermined control timing. Each laser scanner 3 scans and exposes the surface of each photosensitive drum 1 with a laser beam L modulated in accordance with an image signal of each color (exposure process). As a result, an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 1 (the surface potential of the exposed portion of the photosensitive drum 1 is increased). The formed electrostatic latent image is developed as a toner image by the developing device 4 (development process). In this example, the electrostatic latent image is reversely developed with a negatively charged toner.

  By the electrophotographic image forming process operation as described above, a Y color toner image corresponding to the Y color component of the full color image is formed on the photosensitive drum 1 of the first image forming unit UY. An M color toner image corresponding to the M color component of the full color image is formed on the photosensitive drum 1 of the second image forming unit UM. A C color toner image corresponding to the C color component of the full color image is formed on the photosensitive drum 1 of the third image forming unit UC. A K-color toner image corresponding to the K-color component of the full-color image is formed on the photosensitive drum 1 of the fourth image forming unit UK.

  On the other hand, the paper feed roller 12 of the paper feed mechanism unit 11 is driven at a predetermined control timing. As a result, the sheet-like recording material P stacked and stored in the paper feed mechanism unit 11 is separated and fed. The fed recording material P is guided to the upper surface of the belt 8 on the side of the drive roller 9 through the sheet path 13 and is charged by the suction roller 14 to which a positive polarity bias is applied. Thus, the recording material P is electrostatically attracted to the upper surface of the belt 8 and is conveyed by the rotation of the belt 8. Then, in the process of passing through the transfer portion T of the first image forming portion UY, the Y color toner image on the photosensitive drum 1 side is transferred to the surface of the recording material P (first color transfer process). In the process of passing through the transfer unit T of the second image forming unit UM, the M color toner image on the photosensitive drum 1 side is superimposed and transferred onto the surface of the recording material P on which the Y color toner image has already been transferred ( Second color transfer process). In the process of passing through the transfer unit T of the third image forming unit UC, the C color toner image on the photosensitive drum 1 side is superimposed and transferred onto the surface of the recording material P on which the Y color + M color toner image has already been transferred. (Transfer process of the third color). In the process of passing through the transfer portion T of the fourth image forming portion UK, the K color toner image on the photosensitive drum 1 side is superimposed on the surface of the recording material P on which the Y color + M color + C color toner image has already been transferred. Transferred (transfer process of the fourth color).

  Thus, a full-color unfixed toner image of four colors of Y color + M color + C color + K color is synthesized and formed on the surface of the same recording material P.

  Here, the transfer of the toner image from the photosensitive drum 1 to the recording material P in the transfer unit T of each image forming unit UY / UM / UC / UK has a polarity opposite to the charging polarity of the toner with respect to each transfer unit 5. The transfer is carried out electrostatically by applying a transfer bias of a predetermined potential with a positive polarity. In each image forming unit, toner (transfer residual toner) that is not transferred to the recording material P during transfer and remains on the surface of the photosensitive drum 1 is removed by a drum cleaner 6 having an elastic blade as a cleaning member. Thus, the photosensitive drum 1 whose surface has been cleaned is used for the next image formation.

  The recording material P on which the four-color full-color toner images are synthesized and formed is separated from the belt surface at the downstream end portion in the moving direction of the upper belt portion of the belt 8 and introduced into the fixing device 100. The recording material P is heated and pressurized by the fixing device 100 to mix the color toner images and fix the recording material surface to the surface of the recording material, and form a full-color image formed from the fixing device 100 through the sheet path 15 to form an image. The paper is discharged onto a paper discharge tray 16 on the upper surface of the apparatus.

  It is also possible to output a monochrome image formation or a single color image formation. In this case, when the image forming mode is selected, only the image forming unit corresponding to the image forming mode selected from the first to fourth image forming units UY, UM, UC, and UK performs the image forming operation. . In the other image forming units, the photosensitive drum 1 is rotationally driven but the image forming operation is not performed. Then, a process of transferring the toner image to the recording material P conveyed by the belt 8 is executed in the transfer unit of the image forming unit that has performed the image forming operation.

(2) Fixing device 100
Next, the fixing device 100 as the heating device of the present invention will be described. The fixing device 100 of the present embodiment is a sliding contact type external heating fixing device for the purpose of shortening the startup time and reducing the power consumption.

  FIG. 1 is a schematic cross-sectional view of a main part of the fixing device 100, FIG. 2 is a schematic front view of a partially cut-out part of the fixing device 100, and FIG. A schematic diagram of the cutout and a block circuit diagram of the feeding system, (b) is an enlarged schematic cross-sectional view of the heater.

  Here, in the following description, the front surface of the fixing device 100 is the surface on the recording material inlet side. Left and right are left and right when the fixing device 100 is viewed from the front.

  Reference numeral 110 denotes a fixing roller as a rotating body, and 111 denotes a pressure member that forms a fixing nip portion N as a heated body heating nip portion that heats the recording material P as a heated body in contact with the surface of the fixing roller 110. Pressure roller. Reference numeral 112 denotes a heating member that forms a heating nip H as a rotating body heating unit that contacts the surface of the fixing roller 110 and heats the fixing roller 110 to the outside. Reference numeral 140 denotes a heating member moving unit that moves the heating member 112 so that arbitrary two points on the surface of the heating nip H that contacts the fixing roller 110 have different velocity vectors.

a: Fixing roller 110
The fixing roller 110 basically has a cored bar and an elastic layer formed in a roller shape around the cored bar. The fixing roller 110 of this embodiment includes a cored bar 122, a first elastic layer 120 as a heat insulating layer formed in a roller shape around the cored bar, and a second elastic layer as a heat storage layer formed on the outer peripheral surface thereof. This is a composite layer roller having a layer 119 and a release layer 121 formed on the outer peripheral surface thereof.

  The metal core 122 is a metal metal core such as SUS or aluminum. After the outer surface is subjected to surface roughening treatment such as blast treatment, a first elastic layer (hereinafter referred to as a heat insulating layer) 120 is provided on the outer side.

  When the heat insulating layer 120 has a large heat capacity and high thermal conductivity, heat received from the outer surface is absorbed into the fixing roller 110 and the surface temperature of the fixing roller 110 is unlikely to rise. That is, a material having a low heat capacity, a low thermal conductivity, and a high heat insulating effect can shorten the rise time of the surface temperature of the fixing roller 110.

  As a highly heat-insulating material used for the heat insulating layer 120, sponge rubber obtained by foaming silicone rubber or foam rubber obtained by dispersing hollow fillers in silicone rubber can be used.

  Sponge rubber and foam rubber have thermal conductivity of 0.10 to 0.16 W / m · K, which is about half that of solid rubber with thermal conductivity of about 0.25 to 0.29 W / m · K. It has become. The specific gravity related to the heat capacity is about 1.05 to 1.30 for solid rubber, whereas it is about 0.75 to 0.85 for sponge rubber and bubble rubber, which is also a low heat capacity.

  Therefore, as a preferable form of the heat insulating layer 120 of the fixing roller 110, a sponge rubber or a bubble rubber layer having a heat conductivity of 0.15 W / m · K or less and a specific gravity of 0.85 or less and a high heat insulating effect is preferable. .

  If the outer diameter of the fixing roller 110 is smaller, the heat capacity can be suppressed. However, if the outer diameter is too small, the width of the heating nip portion H and the width of the fixing nip portion N are narrowed, and thus an appropriate diameter is required. As for the thickness of the heat insulating layer 120, if it is too thin, heat easily escapes to the metal core 122, so that an appropriate thickness is required.

  Considering the above, the fixing roller 110 of this embodiment uses a metal cored bar having an outer diameter of φ10 mm as the cored bar 122 in order to form an appropriate heating nip portion H and suppress the heat capacity. The heat insulation layer 120 was formed using sponge rubber having a thickness of 2 mm. Therefore, the outer diameter of the roller with the heat insulating layer 120 formed on the cored bar 122 is φ14 mm.

  The second elastic layer (hereinafter referred to as a heat storage layer) 119 is a solid rubber layer having a high heat transfer effect and a certain heat capacity formed of silicone rubber. The heat storage layer 119 has a thermal conductivity of 0.50 W / m · K to 1.60 W / m · K, and a specific gravity of about 1.05 to 1.30.

  When the thickness of the heat storage layer 119 is small, the heat capacity becomes small, so that the heat supply to the recording material such as paper becomes insufficient. On the other hand, when the thickness of the heat storage layer 119 is large, the heat supply effect to the material is increased, but unnecessary heat is also stored, so that the efficiency is poor and it takes time to warm the fixing device. Therefore, the preferable thickness of the heat storage layer 119 is in the range of 0.1 to 0.3 mm, more preferably about 0.15 mm.

  The release layer 121 is a release layer for toner, and in this embodiment, is a release layer made of perfluoroalkoxy resin (PFA). The release layer 121 may be a tube coated or a surface coated with a paint, but in this embodiment, a tube having excellent durability was used.

  The material of the release layer 121 may be a fluororesin such as polytetrafluoroethylene resin (PTFE) or tetrafluoroethylene-hexafluoropropylene resin (FEP) in addition to PFA. Or what gave GLS latex coating may be used.

  If the surface hardness of the fixing roller 110 is low, the width of the heating nip portion H can be obtained even at a light pressure. However, if the surface hardness is too low, the durability deteriorates. In this embodiment, Asker-C hardness (4.9 N load) is used. The angle was 40 to 45 °.

  The fixing roller 110 has shaft portions 122L and 122R on both left and right ends of the cored bar 122 rotatably supported between the left and right side plates 151L and 151R of the fixing device housing 150 via bearing members 152L and 152R, respectively. It is fixedly arranged. A drive gear 153 is fixedly disposed on the shaft 122R on the right end side of the cored bar 122. Driving force is transmitted from the driving means 154 to the drive gear 153, and the fixing roller 110 is rotationally driven at a predetermined surface movement speed in the clockwise direction indicated by an arrow R2 in FIG. 1, in this embodiment, 100 mm / sec. .

b: Pressure roller 111
The pressure roller 111 preferably has a low heat capacity and low thermal conductivity so as not to take heat of the fixing roller 110. In this embodiment, the same configuration as the fixing roller 110 is used. That is, the outer diameter is 14 mm, a heat insulating layer 124 (sponge rubber) having a thickness of 2 mm is formed on the outer side of the iron cored bar 126, and a heat storage layer 123 (solid rubber having a thickness of about 0.15 mm is further formed thereon. ) And a release layer 125 made of PFA is formed.

  The pressure roller 111 is arranged below the fixing roller 110 in parallel with the fixing roller 110. The pressure roller 111 rotatably supports the shaft portions 126L and 126R on the left and right ends of the cored bar 126 between the left and right side plates 151L and 151R of the fixing device casing 150 via bearing members 155L and 155R, respectively. And is slidable in the vertical direction. The left and right bearing members 155L and 155R are urged and moved upward by a predetermined pressing force in the upward direction A2 by the pressure springs 128L and 128R, respectively. As a result, the pressure roller 111 is pressed against the lower surface of the fixing roller 110 against the elasticity of both rollers, and a fixing nip portion N having a predetermined width is formed in the recording material conveyance direction. In the present embodiment, the pressure roller 111 is pressed against the fixing roller 110 with a force of 2.2 N to form a fixing nip portion N having a width of 5 mm.

  The pressure roller 111 is rotated in the counterclockwise direction indicated by an arrow R3 in FIG.

c: Heating member 112
The heating member 112 is disposed on the upper side of the fixing roller 110, that is, on the opposite side of the fixing roller 110 from the pressure roller 111.

  The heating member 112 includes a heater 113 as a heating element, and a sliding sheet 132 as a sliding member (sliding layer) interposed between the heater 113 and the fixing roller 110. The heater 113 is held by a heater holder 118. As will be described later, the heater holder 118 is pressed in the downward direction A1 with a predetermined pressing force by the pressing means, so that the heater 113 is elastic on the upper surface of the fixing roller 110 with the sliding sheet 132 interposed therebetween. It is in close contact with As a result, a heating nip H having a predetermined width is formed in the fixing roller rotation direction in which the heating member 112 contacts the surface of the fixing roller 110 to heat the fixing roller externally. In this embodiment, the heating member moving unit 140 moves the sliding sheet 132 of the heating member 112 so that any two points on the surface contacting the fixing roller 110 in the heating nip H have different velocity vectors. Let

With reference to FIG. 3, the heater 113 basically has a heating resistor 115 formed on the surface of an elongated plate-like substrate 114 along the length of the substrate in this embodiment. The substrate 114 is formed of an insulating ceramic substrate such as alumina or aluminum nitride, or a heat resistant resin substrate such as polyimide, PPS, or liquid crystal polymer. The heating resistor 115 is obtained by screen-printing a paste of a heating resistor material such as Ag / Pd (silver palladium), RuO ₂ , Ta ₂ N on the surface of the substrate 114 and then firing it. The heating resistor 115 has, for example, a linear form having a thickness of about 10 μm, a width of about 1 to 5 mm, and a required length (a length slightly longer than the maximum sheet passing width). Power supply electrode portions 115 </ b> L and 115 </ b> R are formed on the substrate surface portions on both ends of the heating resistor 115 so as to be electrically connected to the heating resistor 115. Further, in this embodiment, the substrate surface on which the heating resistor 115 is formed is covered with the heating resistor 115 to form a glass layer having a thickness of 50 μm as the heating element protection layer 116. In addition, a temperature detection element 117 such as a thermistor for detecting the temperature of the heater 113 is provided at a substantially central portion in the longitudinal direction of the substrate on the back side of the substrate 114 (on the side opposite to the side on which the heating resistor 115 is formed). Has been placed.

  The heater holder 118 is formed of a heat-resistant resin such as liquid crystal polymer, phenol resin, PPS, or PEEK. The lower the thermal conductivity, the higher the thermal efficiency for heating the fixing roller surface. Therefore, the heater holder 118 may include a hollow filler such as a glass balloon or a silica balloon in the resin layer.

  The heater 113 is fixedly held by being fitted in a groove portion provided in the heater holder 118 along the longitudinal direction so that the surface side having the heating resistor 115 is exposed to the outside. The heater holder 118 is arranged in parallel with the fixing roller 110 on the upper side of the fixing roller 110 with the heater 113 side facing downward. The heater holder 118 is arranged to be slidable in the vertical direction by engaging both left and right ends with the vertical slit holes 156l and 156R of the left and right side plates 151L and 151R of the fixing device casing 150, respectively. The movement of the heater holder 118 in the fixing roller rotation direction and the movement in the direction opposite to the fixing roller rotation direction are restricted by slit holes 156l and 156R with which the end portions of the heater holder 118 are engaged. The left and right end portions of the heater holder 118 are pressed and moved downward by a predetermined pressing force by pressing springs 157L and 157R as pressing means, respectively. As a result, the sliding sheet 132 as a heating member is sandwiched between the heater 113 and the fixing roller 110 and pressed against the elasticity of the fixing roller 110 against the fixing roller 110. With this pressure contact, a fixing roller heating nip H having a predetermined width is formed between the fixing roller 110 and the sliding sheet 132 in the rotation direction of the fixing roller. In this embodiment, the heater 113 is pressed against the fixing roller 110 with a force of 0.2 N across the sliding sheet 132 to form a heating nip portion H having a width of about 3 mm. That is, the heater 113 contacts the fixing roller 110 through the sliding sheet 132 to form the heating nip portion H.

  As a material used for the sliding sheet 132, it is preferable to use a fluororesin such as PFA excellent in releasability with toner and PTFE excellent in slidability. When the thickness of the sliding sheet 132 is large, the heat of the heater 113 is difficult to be transmitted to the fixing roller 110, and when the thickness is small, the durability is insufficient. Therefore, the thickness of the sliding sheet 132 is preferably about 1 to 100 μm. . In this embodiment, a PFA sheet having a thickness of 50 μm is used as the sliding sheet 132. A heat-resistant silicone grease was applied to the surface of the sliding sheet 132 in contact with the heater 113 in order to increase the heat transfer efficiency from the heater 113.

  The control circuit unit 200 starts to rotate the fixing roller 110 at a predetermined control timing of image forming sequence control. The pressure roller 111 rotates following the rotational driving of the fixing roller 110. In addition, the control circuit unit 200 starts power supply to the heater 113. That is, as shown in FIG. 3A, power is supplied from the commercial power supply (AC power supply) 170 to the left and right power supply electrode portions 115L and 115R of the heater 113 through the triac 171 via the power supply connectors 172L and 172R. Is done. As a result, the heating resistor 115 between the electrode portions 115L and 115R generates heat over the entire length, and the effective heating area width K of the heater 113 rises rapidly and steeply. The effective heating area width K of the heater 113 is slightly longer than the maximum sheet passing width J (FIG. 2) of the recording material P that is passed through the fixing device 100. The temperature information of the heater 113 is detected by the temperature detection element 117 on the back side of the heater, and the electrical information regarding the temperature output from the temperature detection element 117 is supplied to the control circuit unit via the A / D converter 173. Enter 200. The control circuit unit 200 controls the electric power supplied to the heater 113 to a predetermined level by controlling the phase or the wave number of the triac 171 based on the electrical information regarding the temperature input from the temperature detection element 117. As a result, the heater 113 is temperature-controlled to a predetermined fixing temperature (target temperature). The temperature detection element 117 monitors the abnormal temperature rise of the heater 113 as well as the temperature control of the heater 113 as described above.

  Then, the heat of the heater 115 whose temperature is controlled to a predetermined fixing temperature is conducted to the sliding sheet 132, and the surface of the fixing roller 110 is heated in the heating nip H where the sliding sheet 132 and the fixing roller 110 are in close contact with each other. Heat. That is, the surface of the fixing roller 110 is externally heated at the heating nip portion H by the heating member 112 including the heater 113 and the sliding sheet 132, so that the temperature is raised to a predetermined fixing temperature in a short time (reduction in start-up time). ). Further, since unnecessary portions are not heated, energy consumption can be reduced (low power consumption).

  After the surface of the fixing roller 110 has been heated to a predetermined fixing temperature in a short time, the recording material P onto which the unfixed toner image t has been transferred is conveyed to the fixing nip N. Then, the heat on the surface of the fixing roller 110 moves to the unfixed toner image t and the recording material P, and the toner image t is fixed on the surface of the recording material P with heat and pressure.

(3) Heating member moving means 140
Next, a heating member moving unit 140 that moves the heating member 112 so that any two points on the surface of the heating member 112 that contacts the fixing roller 110 in the heating nip portion H have different velocity vectors, which is a feature of the present embodiment. Will be described.

  In the case of this embodiment, the heater 113 which is a heating element constituting the heating member 112 is held by the heater holder 118, and the heater holder 118 does not move in the same direction as the rotation direction of the fixing roller 110 and in the opposite direction. Thus, the fixing device casing 50 is fixed. The sliding sheet 132 constituting the heating member 112 is movable between the heater 113 and the fixing roller 110 in the same direction as the rotation direction of the fixing roller 110 and in the opposite direction. In the case of this embodiment, the sliding sheet 132 corresponds to a heating member. In the present embodiment, the heating member moving unit 140 is configured so that any two points on the surface of the heating nip H that contacts the fixing roller 110 have different velocity vectors for the sliding sheet 132 of the heating member 112. Move.

  FIG. 4 is a schematic plan view of the heating member moving means 140. The width W of the sliding sheet 132 sandwiched between the heater 132 and the fixing roller 110 to form the heating nip H is longer than the effective heating area width K (FIG. 3) of the heater 132. . A support sheet metal 131 longer than the width W of the sliding sheet 132 is attached to the side upstream of the heating nip H of the sliding sheet 132 in the fixing roller rotation direction. Left and right slide cams 130L fixed to cam shafts 133 that are rotatably supported between the left and right side plates 151L and 151R of the fixing device housing, respectively. It is in contact with 130R. A cam rotation gear 134 is fixedly disposed on the right end side of the cam shaft 133. Driving force is transmitted from the driving means 154 to the gear 134, and the left and right slide cams 130L and 130R are rotationally driven at a predetermined speed in the clockwise direction indicated by the arrow R4 in FIG.

  When the slide cams 130L and 130R rotate, the sliding sheet support sheet metal 131 in contact with these cams is pushed by the slide cams 130L and 130R, and the sliding sheet 132 is an arrow that is opposite to the fixing roller rotation direction R2. Move in the direction of A7. As shown in FIG. 1, since the fixing roller 110 rotates in the R2 direction, a force that is always pulled back in the direction of arrow A8 acts on the sliding sheet 132 sandwiched between the heater 113 and the fixing roller 110. Therefore, by devising the shape of the slide cams 130L and 130R, the rotation direction A2 and the reverse direction of the fixing roller 110 in various patterns in a state where the sliding sheet 132 is sandwiched between the heater 113 and the fixing roller 110. It can be moved in the direction of rotation.

  Here, the shape of the slide cam 130 (LR) used in the present embodiment will be described with reference to FIG. As shown in FIG. 5, a state in which the point a on the slide cam 130 is in contact with the sliding sheet support sheet metal 131 is an initial state.

  When the slide cam 130 is rotated 90 ° in the direction of the arrow R4 from the initial state, the point b on the slide cam 130 then contacts the sliding sheet support sheet metal 131. Thus, in the process in which the slide cam 130 rotates by 90 °, the diameter of the slide cam 130 changes from 6 mm to 9 mm. As a result, the sliding sheet support sheet metal 131 is pushed in the direction of arrow A7 by the slide cam 130, and the sliding sheet 132 attached to the sliding sheet support sheet metal 131 also moves 3 mm in the direction of arrow A7.

  When the slide cam 130 is further rotated by 90 °, the contact point between the slide sheet supporting sheet metal 131 and the slide cam 130 moves from the point b to the point c. In this case, since the diameter of the slide cam 130 remains 9 mm, the sliding sheet 132 does not move.

  When the slide cam 130 is further rotated by 90 ° from the point c to the point d, the diameter of the slide cam 130 changes from 9 mm to 6 mm, and the slide sheet 132 is pulled by the rotation of the fixing roller 110 and is 3 mm in the direction of the arrow A8. Move and return to the initial state.

  Finally, when the slide cam 130 rotates 90 ° from the point d to the point a, the diameter of the slide cam 130 is maintained at 6 mm, so the slide sheet 132 does not move.

  If the slide cam 130 is continuously rotated, the above-described series of operations are continuously performed, and the sliding sheet 132 can repeatedly move in the directions indicated by the arrows A7 and A8.

  When the left and right slide cams 130L and 130R have the same cam shape and are arranged in the same phase, the longitudinal direction of the fixing roller of the sliding sheet 132 is aligned and moves in the tangential direction of the fixing roller 110, and the direction of the arrow A7 and the direction of the arrow A8 Reciprocate direction. At this time, any two points on the surface of the heating nip H that contacts the fixing roller 110 of the sliding sheet 132 have the same velocity vector in the tangential direction of the fixing roller 110. Even in this case, the effect of collecting dirt accumulated at the end of the heating nip H can be obtained.

  In this embodiment, the sliding sheet layer 132 is operated so that arbitrary two points on the surface of the sliding nip H that contacts the fixing roller 110 in the heating nip H have different velocity vectors. As a result, the effect of removing foreign matter caught in the heating nip portion H is simultaneously obtained as well as the effect of collecting dirt.

  In order to operate the sliding sheet layer 132 as described above, in this embodiment, the left and right slide cams 130L and 130R have the same cam shape, but the phase difference when the cam rotates is relatively 90. ° Arranged so as to deviate.

  FIG. 6A schematically shows a series of movements of the sliding sheet 132 in this embodiment in one rotation process of the left and right slide cams 130L and 130R. 1) When the rotation of the slide cam is 0 ° (or 360 °), 2) When the rotation is 90 °, 3) When 180 °, 4) When 270 ° The operation state of the sliding sheet 132 is 270 ° Show.

  Further, in FIG. 6B, the amount of movement of the left and right ends of the sliding sheet 132 is shown in a graph. The rotation angle [°] of the slide cams 130L and 130R is shown on the horizontal axis, and the movement amount [mm] of the sliding sheet 132 in the tangent direction of the fixing roller (tangential direction of the rotating body) is shown on the vertical axis (direction of arrow A7). Was defined as a positive movement amount). The solid line represents the end portion movement amount of the sliding sheet 132 moved by the right slide cam 130R, and the dotted line represents the end portion movement amount of the sliding sheet 132 moved by the left slide cam 130L.

  In this way, as a result of shifting the phase of rotation of the left and right slide cams 130L and 130R by 90 °, the sliding sheet 132 moves 3 mm (reciprocating) in the tangential direction of the fixing roller 110 alternately with the phase difference of 90 °. . By such an operation of the sliding sheet 132, arbitrary two points on the surface of the heating nip H that contacts the fixing roller 110 of the sliding sheet layer 132 have different velocity vectors.

  The speed at which the sliding sheet 132 operates is set to a speed at which the series of operations in FIG. 6 is repeated 10 times in one minute.

(4) Description of foreign matter removal effect Here, the mechanism of the foreign matter removal effect in the present embodiment will be described. Even if foreign matter enters the heating nip H, which is a contact portion between the sliding sheet 132 and the fixing roller 110, most of the foreign matter is discharged downstream of the heating nip H as the fixing roller 110 rotates. However, the foreign matter may get caught in the heating nip portion H due to the influence of the shape of the foreign matter or the minute unevenness of the sliding sheet 132. When the foreign matter stays in the heating nip portion N, the fixing roller 110 is rotated, and therefore, the foreign matter continues to damage the surface layer of the fixing roller 110 and a serious vertical stripe is generated on the fixing roller 110. Here, the foreign matter is sand, paper fiber, or the like that exists in the environment where the heating device is used.

  When the sliding sheet 132 is moved and operated so that any two points on the surface of the heating nip portion H have different velocity vectors as in this embodiment, the foreign matter remaining in the heating nip portion H is effectively removed. Can be removed.

  The moving direction of the sliding sheet 132 and the force applied to the foreign matter remaining in the heating nip portion H when the sliding sheet 132 is moved by the method of this embodiment will be described with reference to FIG. In FIG. 7, the slide cams 130L and 130R rotate 90 °, and the right half of the sliding sheet support substrate 131 is pushed by the slide cam 130R, so that the rotation direction of the fixing roller 110 is opposite (the direction of arrow A7). It is a figure showing the process which moves 3 mm.

  As described above, since the left and right reciprocating cams 130L and 130R have a 90 ° phase difference, the sliding sheet 132 does not move even if the left slide cam 130L rotates. At this time, the sliding sheet 132 moves in the direction of the arrow A7 while rotating slightly with the substantially fixed point M as a fulcrum.

  Here, attention is paid to points I1 and I2, which are arbitrary two points on the surface of the heating nip H that contacts the fixing roller 110 of the sliding sheet 132. By the rotation operation of the sliding sheet 132, the point I1 and the point I2 are moved by velocity vectors L1 and L2, respectively. The velocity vectors L1 and L2 are vectors having different directions and sizes.

  Further, the point I1 and the point I2 generate components that move not only in the tangential direction (L1p and L2p direction in the drawing) of the fixing roller 110 but also in the fixing roller longitudinal direction (L1s and L2s direction in the drawing). .

  Accordingly, since the frictional force acts on the foreign matter remaining at the points I1 and I2 not only in the tangential direction of the fixing roller 110 but also in the longitudinal direction of the fixing roller 110, the foreign matter remaining in the heating nip portion H can be easily moved. Become. Accordingly, the foreign matter remaining on the right side of the heating nip portion H can be effectively removed from the heating nip portion H. In other words, the foreign matter remaining on the right side of the heating nip H is effectively discharged downstream of the heating nip H as the fixing roller 110 rotates.

  In the case of the present embodiment, any two points of the heating nip H have different velocity vectors. Therefore, for example, even if the foreign object moves from the point I1 to another point, the foreign object receives a force different from that at the point I1 at the moved point, so that the foreign object does not deeply damage one direction in which the fixing roller 110 is present. .

  When the slide cams 130L and 130R further rotate 90 ° from the state of FIG. 7, the substantially fixed point M moves to the right side of the sliding sheet support sheet metal 131, and this time the left side of the sliding sheet 132 rotates slightly while the arrow A7 Move in the direction. Accordingly, the foreign matter remaining on the left side of the heating nip portion H can be effectively removed from the heating nip portion H by the same mechanism as described above. In other words, the foreign matter remaining on the left side of the heating nip H is effectively discharged downstream of the heating nip H as the fixing roller 110 rotates.

(5) Explanation of dirt collection effect Next, the mechanism of the dirt collection effect will be explained. FIG. 8 is an enlarged view of the vicinity of the heating nip portion of the conventional configuration. As shown in FIG. 8, when there is toner t that could not be fixed on the recording material on the surface of the fixing roller 110, the heating nip portion H or the upstream end portion or downstream side of the heating nip portion H in the fixing roller rotation direction. The toner t may adhere to the end of the toner. It is often the end V on the downstream side of the heating nip in the rotation direction of the fixing roller 110 in many cases. If the number of sheets to be passed is increased in such a state, toner accumulates at the downstream end V, and drops onto the recording material for some reason, resulting in an image defect.

  Not only the toner but also paper dust generated from the recording material P is offset to the fixing roller 110 and accumulates at the downstream end V in the downstream end V. Therefore, in the following description, what adheres to the downstream end V or the heating nip H is simply referred to as dirt G.

  FIG. 9A shows a time point when the slide cams 130L and 130R rotate at 0 °. (B) represents a point in time when the slide cams 130L and 130R are rotated 90 °. That is, it represents the state of FIG.

  As shown in (a) of FIG. 9, it is assumed that dirt G adheres at the downstream end of the heating nip. When the slide cam 130R is rotated 90 ° in the direction of the arrow R6 from this state, the sliding sheet 132 is opposite to the rotation direction R2 of the fixing roller 110 (the direction of the arrow A7) as shown in FIG. The dirt G moves into the heating nip portion. The dirt G entering the heating nip portion H is scraped off by the fixing roller 110 and can be transferred to the surface of the fixing roller 110 as shown in FIG. The dirt G transferred to the fixing roller 110 moves to the pressure roller 111 having a temperature lower than that of the fixing roller 110 when moving to the fixing nip portion N. Next, when the recording material P is conveyed to the fixing nip portion N, the dirt G on the pressure roller 111 adheres to the back surface (non-image surface) of the recording material P and is collected.

  Further, when the recording material P passes through the fixing nip portion N, the sliding sheet 132 is moved in the direction opposite to the rotation direction of the fixing roller 110 to transfer the dirt G to the surface of the fixing roller 110. The dirt G can be discharged to the surface (image surface) of the recording material P, and the dirt can be collected.

  If the dirt G is collected after collecting to a certain extent, the dirt G discharged on the recording material becomes conspicuous. Therefore, it is preferable to collect the dirt G frequently. In this embodiment, the sliding sheet 132 is always operated as described above during the sheet passing.

  In this embodiment, the reciprocating cams 130L and 130R at the left and right ends are rotated by 90 ° and the left and right ends of the sliding sheet 132 are moved alternately. To be done.

  Further, when the sliding sheet 132 is moved as in this embodiment, the sliding force (frictional force) of each point is different, so that dirt that has entered the heating nip portion H or adheres to the heating nip portion. The effect of collecting dirt and the like is enhanced in the same manner as the foreign matter removal effect.

  As described above, by moving the sliding sheet 132 so that any two points on the surface of the heating nip H have different velocity vectors, a frictional force is randomly generated at each point of the heating nip H. appear. Therefore, the foreign matter remaining in the heating nip portion H can be effectively removed, and the dirt collecting effect is also effectively improved.

  In this embodiment, the phase difference at which the left and right slide cams 130L and 130R rotate is set to 90 °. However, the phase difference may be changed as long as the same effect as described above can be obtained. Further, the moving amount, speed, and frequency of the slide cams 130L and 130R are not limited to the present embodiment. Further, the method of moving the sliding sheet 132 is not limited to the method using the cam of this embodiment, and any other method may be used so that any two points on the surface of the heating nip of the sliding sheet 132 have different velocity vectors. If so, the same effect can be obtained.

  In this embodiment, the sliding sheet 132 is a PFA sheet, but a thin metal such as SUS coated with PFA may be used. However, since the effect of the present invention can be obtained if the metal used as the sliding sheet moves as in this embodiment, the above-described effects are impaired even if the metal used for the sliding sheet is not coated with a fluororesin such as PFA. Absent.

[Example 2]
A second embodiment of the present invention will be described below. In the present embodiment, the image forming apparatus that forms an unfixed toner image on the recording material is the same as that in the first embodiment, and thus the description thereof is omitted. In the sliding contact type external heating and fixing apparatus 100, the same members as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  The fixing device 100 according to the present embodiment is different in any two points on the surface of the heating nip portion of the sliding sheet 132 only when the sliding sheet 132 is moved in the direction opposite to the rotation direction of the fixing roller 110 (A7 direction). A means for operating the sliding sheet 132 so as to have a velocity vector was used.

  In the first embodiment, the two left and right slide cams 130L and 130R arranged on both ends of the sliding sheet supporting sheet metal 131 have the same shape. In this embodiment, the left and right slide cams 130L and 130R have different shapes.

  The right slide cam 130R has the same shape as the cam (FIG. 5) used in Example 1 (see FIG. 3). The left slide cam 130L has the shape shown in FIG.

  FIG. 11A shows a series of processes in one rotation process of the sliding sheet 132 when the left and right slide cams 130L and 130R having different shapes are used as described above and the cam is rotated in the direction of the arrow R4. It is a schematic representation of movement. 1) When the rotation of the slide cam is 0 ° (or 360 °), 2) When the rotation is 90 °, 3) When 180 °, 4) When 270 ° The operation state of the sliding sheet 132 is 270 ° Show.

  Further, in FIG. 11B, the movement amount of the left and right ends of the sliding sheet 132 is shown in a graph. The rotation angle [°] of the slide cams 130L and 130R is shown on the horizontal axis, and the movement amount [mm] of the sliding sheet 132 in the tangent direction of the fixing roller (tangential direction of the rotating body) is shown on the vertical axis (direction of arrow A7). Was defined as a positive movement amount). The solid line represents the end portion movement amount of the sliding sheet 132 moved by the right slide cam 130L (FIG. 5), and the dotted line represents the end portion movement amount of the sliding sheet 132 moved by the left slide cam 130R (FIG. 10). ing.

  The process of moving the left and right ends of the sliding sheet 132 alternately in the direction of the arrow A7 and the effects associated therewith are the same as those in the first embodiment, and the description thereof will be omitted.

  When the sliding sheet 132 is moved in the same direction as the rotation direction of the fixing roller 110 (direction of arrow A8) as in this embodiment, all points on the surface of the heating nip of the sliding sheet 132 have the same speed. Even with a vector (in the direction of arrow A8), the rate of occurrence of scratches due to foreign matter is small.

  FIG. 12 shows an enlarged cross-sectional view of the downstream side of the heating nip. The sliding sheet 132 follows the rotation R2 of the fixing roller 110 and moves in the direction of the arrow A8. Therefore, as shown in FIG. 12, the foreign matter is also sandwiched between the sliding sheet 132 and the fixing roller 110 and discharged outside the heating nip portion at a substantially same speed. Therefore, the rate at which foreign matter damages the fixing roller 110 is reduced.

  As described above, in this embodiment, only when the sliding sheet 132 moves in the reverse direction A7 with respect to the rotation direction R2 of the fixing roller 110, two arbitrary points on the surface of the heating nip portion of the sliding sheet 132 are obtained. Are operated so that they have different velocity vectors. Even in this case, a foreign matter removing effect and a dirt collecting effect can be obtained.

  In the configuration of the present embodiment, as in the first embodiment, the moving amount, speed, and frequency of the slide cam 130 are not limited to this. Further, the method of moving the sliding sheet 132 is not limited to the method using the cam described above, and other methods may be used so that any two points on the surface of the heating nip of the sliding sheet 132 have different velocity vectors. In this case, the same effect can be obtained.

[Example 3]
A third embodiment of the present invention will be described below. In the present embodiment, the image forming apparatus that forms an unfixed toner image on the recording material is the same as that in the first embodiment, and thus the description thereof is omitted. In the sliding contact type external heating and fixing apparatus 100, the same members as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  In the present embodiment, regarding the sliding sheet 132, other movement operation patterns other than the first embodiment and the second embodiment will be described.

  Also in this embodiment, the left and right slide cams 130L and 130R having different shapes were used. The left slide cam 130L has the same shape as the left cam 130L (FIG. 10) used in the second embodiment. The right slide cam 130R has the shape shown in FIG.

  FIG. 14A shows a series of steps in one rotation process of the sliding sheet 132 when the left and right slide cams 130L and 130R having different shapes are used as described above and the cam is rotated in the direction of the arrow R4. It is a schematic representation of movement. 1) When the rotation of the slide cam is 0 ° (or 360 °), 2) When the rotation is 90 °, 3) When 180 °, 4) When 270 ° The operation state of the sliding sheet 132 is 270 ° Show.

  Further, in FIG. 14B, the movement amount of the left and right ends of the sliding sheet 132 is shown in a graph. The rotation angle [°] of the slide cams 130L and 130R is shown on the horizontal axis, and the movement amount [mm] of the sliding sheet 132 in the tangent direction of the fixing roller (tangential direction of the rotating body) is shown on the vertical axis (direction of arrow A7). Was defined as a positive movement amount). The solid line represents the end portion movement amount of the sliding sheet 132 moved by the left slide cam 130L (FIG. 10), and the dotted line represents the end portion movement amount of the sliding sheet 132 moved by the right slide cam 130R (FIG. 13). ing.

  The sliding sheet 132 moves in a pattern different from that in the first embodiment. However, when the sliding sheet 132 moves in either the direction of the arrow A7 or the direction of the arrow A8, as described in the first embodiment, two arbitrary points on the surface of the heating nip portion of the sliding sheet 132 are used. Will have different velocity vectors.

  Therefore, as described above, the effect of collecting the foreign matter that has entered the heating nip portion H and the effect of collecting dirt accumulated in the heating nip portion H can be further enhanced.

[Other Examples]
1) In order to obtain the effect of the present invention, the heating member may be moved so that any two points on the heating nip surface of the heating member 112 have different velocity vectors.

  Therefore, a configuration in which the heating nip H is formed by directly contacting the heater 113 with the surface of the fixing roller 110 without using the sliding sheet 132 may be used. In that case, both ends in the longitudinal direction of the heater 113 are moved using a cam or the like as in the above-described embodiment. Or if the effect similar to the above is acquired, it will not be restricted to the method using a cam.

  When the heater 113 is moved in the tangential direction of the fixing roller 110, if the heating resistor 115 of the heater 113 is removed from the heating nip H, the surface temperature of the fixing roller 110 is lowered. Therefore, it is preferable to determine the amount of movement of the heater 113 so that the heating resistor 115 does not come off the heating nip H.

  2) In the first to third embodiments, a roller member is used as the rotating body 110 that heats the object to be heated by being externally heated. However, the rotating body is in the form of an endless belt member that rotates. You can also.

  3) Further, in Example 1 to Example 3, the pressure roller is used as the pressure member for forming the fixing nip portion N which is the heated object heating nip portion, but the pressure member is not limited to the roller. A pad member that does not rotate may be used.

  4) The heating device of the present invention is not limited to the image heating and fixing device as in the embodiments, but also, for example, an image heating device that heats a recording material carrying an image to improve surface properties such as gloss, etc. It can also be used as an image heating device that presupposes a received image. It can also be used as an image heating device for image drying in an inkjet printer or the like. Further, the present invention is not limited to an image heating apparatus, and can be used as a heating apparatus that feeds a sheet-like object to be heated and performs a drying process, a laminating process, a wrinkle removing process, and the like.

Sectional schematic diagram of the main part of a sliding contact type external heating fixing device (heating device) in Example 1 Schematic diagram of the front part of the fixing device (A) is a schematic diagram of a partial cutout on the surface side of the heater and a block circuit diagram of a power supply system, and (b) is an enlarged schematic cross-sectional view of the heater. Schematic plan view of sliding sheet moving mechanism (heating member moving means) Shape of slide cam used in Example 1 (A) is a figure showing a series of operation | movement of the sliding sheet (heating member) in Example 1, (b) is a figure showing the movement amount of the sliding sheet. Detailed operation explanation of sliding sheet Sectional view of the heating nip in the conventional example (A) And (b) is an explanatory view of a dirt collection process Shape of slide cam used in Example 2 (A) is a diagram showing a series of operations of the sliding sheet in Example 2, (b) is a diagram showing the amount of movement of the sliding sheet Explanatory drawing of the foreign material collection process in Example 2 Shape of slide cam used in Example 3 (A) is a diagram showing a series of operations of the sliding sheet in Example 3, (b) is a diagram showing the amount of movement of the sliding sheet in Example 3 Schematic configuration diagram of an example of an image forming apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum 2 ... Charger 3 ... Exposure apparatus 4 ... Developing device 5 ... Transfer roller 6 ... Photosensitive drum cleaner 8 which cleans a photosensitive drum ... Recording material conveyance belt 9 ... Recording material conveyance belt drive roller 10 ... Recording material conveyance belt Tension roller 12 for tensioning ... Paper feed roller 14 ... Adsorption roller 100 for charging the recording material and adsorbing it to the recording material conveying belt ... Fixing device 110 ... Fixing roller 111 ... Pressure roller 113 ... Heating heater for heating the contact roller of the fixing roller 117 ... Temperature detecting element 119 for detecting the temperature of the back side of the heater ... Elastic layer 120 of the fixing roller ... Heat insulating layer 121 of the fixing roller ... Release layers 130L and 130R of the fixing roller made of fluororesin ... Slide cam 132 ... Sliding sheet (heating member)

Claims (5)

A rotating member, and a heating member that forms a rotating member heating nip that contacts the surface of the rotating member to externally heat the rotating member, and contacts the heated object to the heated surface of the rotating member In a heating device that heats
Heating means characterized by comprising heating member moving means for moving the heating member so that any two points on the surface of the heating member contacting the rotating body in the rotating body heating nip have different velocity vectors. apparatus.   The heating member moving means is an arbitrary unit on the surface of the rotating member heating nip that contacts the rotating member only when the heating member is moved in the direction opposite to the rotating direction of the rotating member. The heating apparatus according to claim 1, wherein the heating member is moved so that two points have different velocity vectors.   The heating apparatus according to claim 1 or 2, wherein the heating member moving means reciprocates the heating member in a tangential direction of the rotating body.   The heating apparatus according to any one of claims 1 to 3, further comprising a pressure member that forms a heated object heating nip portion that heats the heated object by contacting the surface of the rotating body.   5. A heating apparatus according to claim 1, wherein the heated object is a recording material carrying an image.

Images