JP5278581B2 - Fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device which can change a nip state between a nip plate (nip member) and a pressure roller (backup member) and can be miniaturized. <P>SOLUTION: A fixing device 100 includes a cylindrical fixing film 110, a heating element (halogen lamp 120) arranged inside the fixing film 110, a nip member (nip plate 130) receiving radiation heat from the heating element, a backup member (pressure roller 150) holding the fixing film 110 between the backup member and the nip member, to form a nip part N1 between the backup member and the fixing film 110, a first support member (guide member 170) integrally supporting the heating element and the nip member, and a second support member movably supporting the first support member, so as to move the nip member with respect to the backup member. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a fixing device that thermally fixes a developer image transferred to a recording sheet.

  As a fixing device used in an electrophotographic image forming apparatus, a heating plate that forms a nip portion between a cylindrical fixing film, a heater disposed in the fixing film, and a pressure roller via the fixing film (Nippon board) is known (for example, refer to patent documents 1). In this fixing device, the developer image on the sheet is thermally fixed while the sheet is conveyed between the fixing film supported by the nip plate and the pressure roller (nip portion).

JP 2008-233886 A

  By the way, in the conventional fixing device, the pressure in the nip portion (for example, for fixing the paper with different thicknesses such as plain paper and cardboard paper well, for taking out the paper jammed at the nip portion) Hereinafter, it is desired to change the state of the nip portion (hereinafter also referred to as “nip state”) such as “nip pressure”) and the width of the nip portion (hereinafter also referred to as nip width). As a structure for changing the nip state, for example, a structure in which only the nip plate is advanced and retracted with respect to the pressure roller is conceivable.

  However, when adopting a structure in which only the nip plate is moved forward and backward with respect to the pressure roller, the clearance between the nip plate and the heater is prevented so that the nip plate does not contact the heater that does not move with respect to the pressure roller. Therefore, there is a problem that the size of the apparatus increases.

  Therefore, the present invention provides a fixing device that can change the nip state between the nip plate (nip member) and the pressure roller (backup member) and can reduce the size of the device. Objective.

The present invention that solves the above-mentioned problems is arranged so as to contact a cylindrical fixing film, a heating element that is disposed inside the fixing film and that is long in the axial direction of the cylindrical fixing film, and an inner surface of the fixing film. A fixing device comprising: a disposed nip member; and a backup member that forms a nip portion between the fixing film and the fixing film by sandwiching the fixing film between the nip member and the axial direction. A pair of first support members that are disposed on both ends of the heating element and integrally support the heating element and the nip member; and the pair of first support members so that the nip member moves relative to the backup member. Bei a second support member for movably supporting the first support member, elongated in the axial direction of the tubular fixing film, and a stay for supporting the nip member from the opposite side of the nip The stay is fixed to the first support member, the nip member is fixed to the stay, the heating element is characterized by being fixed to the first support member.

  According to the present invention, since the nip member can be moved relative to the backup member by moving the first support member relative to the second support member, the nip state can be favorably changed. Further, since the nip member is integrally supported by the first support member together with the heating element, the clearance between the heating element and the nip member can be reduced, and the apparatus can be downsized.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to change the nip state between a nip member and a backup member, size reduction of an apparatus can be achieved.

1 is a diagram illustrating a schematic configuration of a laser printer including a fixing device according to an embodiment of the present invention. 1 is a diagram illustrating a schematic configuration of a fixing device according to an embodiment of the present invention. It is a perspective view of a halogen lamp, a nip plate, a reflecting plate, and a stay. It is the figure which looked at the nip plate, the reflecting plate, and the stay from the conveyance direction. They are the perspective view (a) which looked at the guide member from the upper side, the perspective view (b) which looked at the guide member which attached the stay from the lower side, and the bottom view (c). FIG. 3 is a side view of the fixing device viewed from the left side. FIG. 3 is a perspective view of the fixing device as viewed from the upper rear side. It is a side view showing a fixing device in a state where nip pressure is released. It is explanatory drawing (a), (b) which shows the relationship between a nip plate, a halogen lamp, etc. when changing nip pressure. It is explanatory drawing (a), (b) which shows the relationship between a nip plate, a halogen lamp, etc. when changing a nip width | variety.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, the schematic configuration of the laser printer 1 (image forming apparatus) including the fixing device 100 according to the embodiment of the present invention will be described first, and then the detailed configuration of the fixing device 100 will be described.

<Schematic configuration of laser printer>
As shown in FIG. 1, the laser printer 1 includes a main body housing 2 in which a paper sheet 3 as an example of a recording sheet is fed, an exposure device 4, and a toner image (developer) on the paper P. And the fixing device 100 for thermally fixing the toner image on the paper P.

  In the following description, the direction will be described with reference to the user who uses the laser printer. That is, the right side in FIG. 1 is “front”, the left side is “rear”, the front side is “left”, and the back side is “right”. Also, the vertical direction in FIG.

  The paper feed unit 3 is provided in the lower part of the main body housing 2, and includes a paper feed tray 31 that accommodates the paper P, a paper pressing plate 32 that lifts the front side of the paper P, a paper feed roller 33, and a paper feed pad 34. And paper dust removing rollers 35 and 36 and a registration roller 37 are mainly provided. The paper P in the paper feed tray 31 is brought close to the paper feed roller 33 by the paper pressing plate 32 and separated one by one by the paper feed roller 33 and the paper feed pad 34, and the paper dust removing rollers 35, 36 and the registration roller 37. Then, it is conveyed toward the process cartridge 5.

  The exposure apparatus 4 is arranged at the upper part in the main body housing 2 and mainly includes a laser light emitting unit (not shown), a polygon mirror 41 that is rotationally driven, lenses 42 and 43, and reflecting mirrors 44, 45, and 46. In preparation. In the exposure apparatus 4, the laser light (see the chain line) based on the image data emitted from the laser light emitting part is reflected or passed through the polygon mirror 41, the lens 42, the reflecting mirrors 44 and 45, the lens 43 and the reflecting mirror 46 in this order. The surface of the photosensitive drum 61 is scanned at high speed.

  The process cartridge 5 is disposed below the exposure apparatus 4 and is detachably mounted on the main body housing 2 through an opening formed when the front cover 21 provided on the main body housing 2 is opened. Yes. The process cartridge 5 includes a drum unit 6 and a developing unit 7.

  The drum unit 6 mainly includes a photosensitive drum 61, a charger 62, and a transfer roller 63. The developing unit 7 is configured to be detachably attached to the drum unit 6, and includes a developing roller 71, a supply roller 72, a layer thickness regulating blade 73, and a toner that contains toner (developer). The housing part 74 is mainly provided.

  In the process cartridge 5, the surface of the photosensitive drum 61 is uniformly charged by the charger 62 and then exposed by high-speed scanning of the laser light from the exposure device 4, whereby image data is transferred onto the photosensitive drum 61. An electrostatic latent image based on is formed. Further, the toner in the toner container 74 is supplied to the developing roller 71 via the supply roller 72 and enters between the developing roller 71 and the layer thickness regulating blade 73 to form a thin layer of a certain thickness on the developing roller 71. It is carried on.

  The toner carried on the developing roller 71 is supplied from the developing roller 71 to the electrostatic latent image formed on the photosensitive drum 61. As a result, the electrostatic latent image is visualized and a toner image is formed on the photosensitive drum 61. Thereafter, the paper P is conveyed between the photosensitive drum 61 and the transfer roller 63, whereby the toner image on the photosensitive drum 61 is transferred onto the paper P.

  The fixing device 100 is provided behind the process cartridge 5. The toner image (toner) transferred onto the paper P is thermally fixed onto the paper P by passing through the fixing device 100. The paper P on which the toner image is thermally fixed is discharged onto the paper discharge tray 22 by the transport rollers 23 and 24.

<Detailed configuration of fixing device>
As shown in FIG. 2, the fixing device 100 includes a fixing film 110, a halogen lamp 120 as an example of a heating element, a nip plate 130 as an example of a nip member, a reflection plate 140, and an example of a backup member. A pressure roller 150 and a stay 160 are mainly provided.

  The fixing film 110 is an endless (cylindrical) film having heat resistance and flexibility, and its both ends are guided by a guide member 170 as an example of a regulating member (first support member) described later. ing.

  The halogen lamp 120 is a known heating element that heats the toner on the paper P by heating the nip plate 130 and the fixing film 110. Inside the fixing film 110, a predetermined amount of heat is supplied from the inner surfaces of the fixing film 110 and the nip plate 130. They are arranged at intervals.

  The nip plate 130 is a plate-like member that receives radiant heat from the halogen lamp 120, and is disposed so as to be in sliding contact with the inner surface of the cylindrical fixing film 110. The nip plate 130 transmits the radiant heat received from the halogen lamp 120 to the toner on the paper P through the fixing film 110.

  The nip plate 130 has a thermal conductivity higher than that of a steel stay 160, which will be described later. For example, the nip plate 130 is formed by bending an aluminum plate or the like into a substantially U shape in sectional view. More specifically, the nip plate 130 is bent toward the base portion 131 extending in the front-rear direction (the conveyance direction of the paper P) and upward (the direction from the pressure roller 150 toward the nip plate 130) in a cross-sectional view. The bent portion 132 is mainly included. In the present embodiment, a bent portion 132 that is bent from both front and rear edges of the base portion 131 is formed in order to increase the rigidity of the base portion 131 and to prevent the fixing film 110 from being scraped by the edge of the nip plate 130. However, the present invention is not limited to this, and the bent portion 132 may not be formed.

  Specifically, the base portion 131 is bent and formed so as to protrude toward the pressure roller 150 so that the center portion 131A in the front-rear direction is displaced in the direction perpendicular to the surface of the base portion 131 from the both end portions 131B. Yes. Specifically, the base portion 131 is formed in a hat shape such that the central portion 131A is offset downward from the both end portions 131B.

  Note that the inner surface (upper surface) of the base portion 131 may be painted black or provided with a heat absorbing member. According to this, the radiant heat from the halogen lamp 120 can be efficiently absorbed.

  As shown in FIG. 3, the nip plate 130 further includes an insertion portion 133 that extends in a flat plate shape from the right end portion of the base portion 131, and an engagement portion 134 that is formed at the left end portion of the base portion 131. The engaging portion 134 is formed in a U shape in a side view, and an engaging hole 134B is provided in a side wall portion 134A formed by bending upward.

  As shown in FIG. 2, the reflecting plate 140 reflects the radiant heat from the halogen lamp 120 (radiant heat radiated mainly in the front-rear direction and the upward direction) toward the nip plate 130 (the inner surface of the base portion 131). It is a member and is arranged at a predetermined interval from the halogen lamp 120 so as to surround the halogen lamp 120 inside the fixing film 110.

  By collecting the radiant heat from the halogen lamp 120 to the nip plate 130 with such a reflector 140, the radiant heat from the halogen lamp 120 can be used efficiently, and the nip plate 130 and the fixing film 110 can be heated quickly. Can do.

  The reflection plate 140 is formed by curving an aluminum plate or the like in a substantially U shape in cross section, for example, having a high infrared and far infrared reflectance. More specifically, the reflecting plate 140 mainly includes a reflecting portion 141 having a curved shape (substantially U-shaped in cross section) and a flange portion 142 extending from both ends of the reflecting portion 141 along the outer side in the front-rear direction. . In order to increase the thermal reflectance, the reflection plate 140 may be formed using a mirror-finished aluminum plate or the like.

  As shown in FIG. 3, a total of four flange-like locking portions 143 are formed at both ends of the reflection plate 140 in the left-right direction (the width direction of the paper P) (only three are shown). The locking portion 143 is located above the flange portion 142. As shown in FIG. 4, when the nip plate 130, the reflecting plate 140, and the stay 160 are assembled, a plurality of contact portions 163 of the stay 160 described later are provided. It arrange | positions so that it may pinch | interpose (adjacent to the outermost contact part 163A in the left-right direction).

  As a result, even if the reflection plate 140 tries to move left and right due to vibrations when the fixing device 100 is driven, the position of the reflection plate 140 in the left-right direction is restricted by the locking portion 143 coming into contact with the contact portion 163A. The As a result, it is possible to suppress the displacement of the reflecting plate 140 in the left-right direction.

  As shown in FIG. 2, the pressure roller 150 is a member that forms a nip portion N <b> 1 with the fixing film 110 by sandwiching the fixing film 110 with the nip plate 130. Has been placed.

  The pressure roller 150 is configured to be driven to rotate by a driving force transmitted from a motor (not shown) provided in the main body housing 2, and to rotate with the fixing film 110 (or paper P). The fixing film 110 is driven and rotated by the frictional force.

  The sheet P on which the toner image is transferred is conveyed between the pressure roller 150 and the heated fixing film 110 (nip portion N1), whereby the toner image (toner) is thermally fixed.

  The stay 160 is a member that secures the rigidity of the nip plate 130 by supporting both end portions 131B of the nip plate 130 (base portion 131) in the front-rear direction via the flange portion 142 of the reflection plate 140. The stay 160 has a shape (substantially U shape in cross section) along the outer surface shape of the reflecting plate 140 (reflecting portion 141) and is disposed so as to cover the reflecting plate 140. Such a stay 160 has relatively high rigidity, for example, is formed by bending a steel plate or the like into a substantially U shape in cross-sectional view.

  At the lower ends of the front wall 161 and the rear wall 162 of the stay 160, as shown in FIG. 3, a plurality of contact portions 163 formed in a substantially comb shape are provided.

  Further, a substantially L-shaped locking portion 165 extending downward and further toward the left is provided at the right end portions of the front wall 161 and the rear wall 162 of the stay 160. Further, a holding portion 167 is provided at the left end of the stay 160 and extends leftward from the upper wall 166 and is bent into a substantially U shape in a side view. Engagement bosses 167B (only one is shown) projecting inward are provided on the inner surfaces of the side wall portions 167A of the holding portion 167.

  As shown in FIGS. 2 and 3, a total of four abutting bosses 168 projecting inward are provided at both ends in the left-right direction of the inner surfaces of the front wall 161 and the rear wall 162 of the stay 160. The abutting boss 168 abuts on the reflecting plate 140 (reflecting portion 141) in the front-rear direction. As a result, even if the reflection plate 140 tries to move back and forth due to vibrations when the fixing device 100 is driven, the position of the reflection plate 140 in the front-rear direction is restricted by contacting the contact boss 168. As a result, it is possible to suppress the displacement of the reflector plate 140 in the front-rear direction.

  Further, supported portions 169 projecting outward in the left-right direction are formed at the upper portions of the left and right ends of the stay 160, and the supported portions 169 are supported by guide members 170 described later.

  When the reflecting plate 140 and the nip plate 130 are assembled to the stay 160 described above, the reflecting plate 140 is first attached to the stay 160 so as to be fitted. Since the abutting boss 168 is provided on the inner surfaces of the front wall 161 and the rear wall 162 of the stay 160, the reflecting plate 140 is temporarily held by the stay 160 when the abutting boss 168 contacts the reflecting plate 140. The

  Thereafter, as shown in FIG. 4, the insertion portion 133 of the nip plate 130 is inserted between the locking portions 165 of the stay 160 to engage the base portion 131 (both end portions 131B) with the locking portions 165, and then Then, the engaging portion 134 (engaging hole 134B) of the nip plate 130 and the holding portion 167 (engaging boss 167B) of the stay 160 are engaged.

  Thereby, the both ends 131 </ b> B of the base portion 131 are supported by the locking portion 165 and the engaging portion 134 is held by the holding portion 167, so that the nip plate 130 is held by the stay 160. The reflecting plate 140 is held by the stay 160 in a state where the flange portion 142 is sandwiched between the nip plate 130 and the stay 160.

  As a result, even if the reflection plate 140 tries to move up and down due to vibrations when the fixing device 100 is driven, the flange portion 142 is sandwiched between the nip plate 130 and the stay 160 so that the reflection plate 140 is moved in the vertical direction. The position of is regulated. As a result, it is possible to suppress the positional deviation of the reflecting plate 140 in the vertical direction, and to fix the position of the reflecting plate 140 with respect to the nip plate 130.

  The stay 160 that holds the nip plate 130 and the reflection plate 140 and the halogen lamp 120 are directly fixed to the guide member 170 shown in FIG. That is, the guide member 170 integrally supports the nip plate 130, the reflection plate 140, the stay 160, and the halogen lamp 120.

  The guide members 170 are formed of an insulating material such as a resin, and are arranged one by one on both ends of the fixing film 110 to mainly restrict the movement of the fixing film 110 in the left-right direction (axial direction). . Specifically, the guide member 170 includes a restriction surface 171 for restricting the movement of the fixing film 110 in the left-right direction, a suppressing portion 172 for suppressing deformation of the fixing film 110 inward in the radial direction, and both end portions of the stay 160. Is mainly provided with a holding recess 173.

  The suppressing portion 172 is a rib that protrudes inward in the left-right direction from the restriction surface 171 and is formed in a C shape with the opening facing downward. The suppressing portion 172 suppresses deformation inward in the radial direction by entering the fixing film 110. Further, the opening facing the lower side of the suppressing portion 172 serves as an escape portion for inserting the stay 160 into the holding recess 173.

  The holding recess 173 is a groove that opens downward and penetrates inward in the left-right direction. Of the walls that form the holding recess 173, the pair of side walls 174 that face each other in the front-rear direction are shown in FIGS. ), A pair of engagement protrusions 174A are formed. Each engagement protrusion 174A is formed so as to protrude inward from a position away from the bottom surface 173A of the holding recess 173 (see FIG. 5A).

  5B, when the supported portion 169 of the stay 160 is inserted between the bottom surface 173A of the holding recess 173 and the pair of engaging protrusions 174A, the supported portion 169 moves in the vertical direction. Is regulated by the bottom surface 173A of the holding recess 173 and the pair of engaging protrusions 174A. Thereby, it is possible to suppress the positional deviation of the stay 160 in the vertical direction with respect to the guide member 170.

  In addition, the laterally inner edge 160B of the stay 160 is in contact with the laterally inner surface 174B of the pair of engaging protrusions 174A. As a result, even if the stay 160 tries to move left and right due to vibration or the like when the fixing device 100 is driven, the position of the stay 160 in the left-right direction is restricted by the engagement protrusion 174A coming into contact with the stay 160. As a result, the displacement of the stay 160 in the left-right direction with respect to the guide member 170 can be suppressed.

  Further, the stay 160 is sandwiched between the pair of side walls 174 of the holding recess 173 in the front-rear direction, so that the positional deviation in the front-rear direction is suppressed. As described above, the stay 160 is supported by the guide member 170, whereby the nip plate 130 is integrally supported by the guide member 170 via the stay 160.

  Further, a fixing portion 175 for fixing the halogen lamp 120 is formed on the outer side of the guide member 170 in the left-right direction so as to protrude outward in the left-right direction. A mounting hole 175A for screwing a bolt B (see FIG. 6) is formed on the lower surface of the fixing portion 175. Then, as shown in FIG. 6, the plate-like terminal 121 at the end portion of the halogen lamp 120 is directly fixed to the lower surface of the fixing portion 175 with a bolt B.

  Further, a support plate 176 extending while being appropriately bent substantially rearward (a cam portion 186 side described later) is fixed to the upper surface of the guide member 170. Between the support plate 176 and the upper frame 181 fixed to the upper part of the fixing frame 180, there is a coil spring S that constantly urges the support plate 176 and the guide member 170 downward (on the pressure roller 150 side). Is provided. Thereby, a suitable nip pressure is applied between the nip plate 130 and the pressure roller 150 during printing control.

  The guide member 170 that integrally supports the nip plate 130 and the like and the halogen lamp 120 is supported by a fixing frame 180 as an example of a second support member so as to be movable up and down.

  Specifically, a shaft support groove 182 that supports the pressure roller 150 via a bearing 190 and a support groove 183 that supports the guide member 170 movably up and down are formed on the left and right side walls of the fixing frame 180. Yes.

  An operation lever 184 for moving the guide member 170 up and down is rotatably provided on the left and right side walls of the fixing frame 180. Specifically, as shown in FIG. 7, one end of the operation lever 184 is integrally fixed to a rotation shaft 185 that penetrates the left and right side walls of the fixing frame 180.

  In addition, cam portions 186 that protrude radially outward are integrally fixed to the left and right ends of the rotation shaft 185. Therefore, when the operating lever 184 is rotated and the left and right support plates 176 are pressed upward by the left and right cam portions 186, the left and right guide members 170 resist the urging force of the coil spring S as shown in FIG. To rise. When the operating lever 184 is returned to the original position from this state, the cam portion 186 is detached from the left and right support plates 176 and the left and right guide members 170 are lowered by the urging force of the coil spring S as shown in FIG. To do.

  When the guide member 170 is moved up and down with respect to the fixing frame 180 in this way, as shown in FIGS. 9A and 9B, the nip plate 130 and the halogen lamp fixed integrally to the guide member 170 are provided. 120 moves up and down with respect to the pressure roller 150 supported by the fixing frame 180. As a result, the nip pressure can be changed without changing the clearance between the nip plate 130 and the halogen lamp 120.

According to the above, the following effects can be obtained in the present embodiment.
By moving the guide member 170 relative to the fixing frame 180, the nip plate 130 can be moved relative to the pressure roller 150, so that the nip pressure can be changed favorably. Further, since the nip plate 130 is integrally supported by the guide member 170 together with the halogen lamp 120, the clearance between the nip plate 130 and the halogen lamp 120 can be reduced, and the apparatus can be downsized.

  Since both the guide member 170 and the pressure roller 150 are supported by a single fixing frame 180, the structure is compared with a structure in which the guide member 170 and the pressure roller 150 are supported by separate members and these members are joined. Can be simplified.

  Since the reflecting plate 140 and the stay 160 are integrally supported by the guide member 170, the clearance between the members of the nip plate 130, the halogen lamp 120, the reflecting plate 140, and the stay 160 can be reduced, and further miniaturization can be achieved. Can be planned. Further, since the heat capacity is reduced by reducing the size of the reflecting plate 140 and the like, the nip plate 130 can be heated quickly, and fixing control can be started quickly.

  Since the guide member 170 is formed of an insulating material, the terminal 121 of the halogen lamp 120 can be directly fixed to the guide member 170. For example, the terminal is made into a conductive guide member via an insulating member. The structure can be simplified compared to the structure provided.

  Since the pressure roller 150 is supported by the fixing frame 180 fixed to the main body housing 2, the pressure roller 150 is configured to be immovable from front to back and up and down with respect to the main body housing 2. A mechanism for transmitting a driving force from a provided driving source (not shown) to the pressure roller 150 can be simply configured.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention.

  In the above embodiment, the nip plate 130 is completely separated from the pressure roller 150, that is, the nip pressure is changed to a value close to zero in order to remove the paper P jammed in the nip portion. Is not limited to this. For example, as shown in FIGS. 10A and 10B, the nip width is changed to a normal width (N1) in order to change the nip pressure from a large value to a small value according to the paper type such as plain paper or thick paper. The present invention may be applied to a form in which the width is changed to a width (N2) narrower than that. Further, the position of the nip plate is switched in three stages: a position where the nip width is a normal nip width (N1), a position where the nip width is smaller than this (N2), and a position where the nip plate is completely separated from the pressure roller. It may be configured as follows. Furthermore, the nip plate may be finely moved stepwise so that the nip width is switched in three or more steps.

  In the above embodiment, the nip plate 130 is indirectly supported by the guide member 170 via the stay 160. However, the present invention is not limited to this, and the nip plate may be directly fixed to the guide member. Further, the halogen lamp 120 may be indirectly supported by the guide member 170 via another member.

  In the above embodiment, the guide member 170 is moved in the vertical direction (the direction in which the nip plate and the pressure roller face each other). However, the present invention is not limited to this, and may be moved in the sheet conveyance direction, for example.

  In the embodiment, the fixing frame 180 as the second support member directly supports the guide member 170 as the first support member so as to be movable. However, the present invention is not limited to this, and the second support member is not limited to this. The first support member may be indirectly supported via the member.

In the above embodiment, the reflecting plate 140 and the stay 160 are provided. However, the present invention is not limited to this, and the reflecting plate and the stay may be appropriately omitted.
In the embodiment, the halogen lamp 120 (halogen heater) is exemplified as the heating element. However, the present invention is not limited to this, and may be, for example, an infrared heater or a carbon heater.

  In the embodiment, the pressure roller 150 is exemplified as the backup member. However, the present invention is not limited to this, and may be, for example, a belt-like pressure member.

  In the embodiment, the paper P such as plain paper or postcard is exemplified as the recording sheet, but the present invention is not limited to this, and may be, for example, an OHP sheet.

  In the above embodiment, the laser printer 1 is exemplified as the image forming apparatus including the fixing device of the present invention. However, the present invention is not limited to this, and may be, for example, an LED printer that performs exposure using LEDs. A copying machine other than a printer or a multifunction machine may be used. In the above-described embodiment, an image forming apparatus that forms a monochrome image is exemplified. However, the present invention is not limited to this, and an image forming apparatus that forms a color image may be used.

DESCRIPTION OF SYMBOLS 100 Fixing device 110 Fixing film 120 Halogen lamp 121 Terminal 130 Nip plate 140 Reflecting plate 150 Pressure roller 160 Stay 170 Guide member 180 Fixing frame N1 Nip part P Paper

Claims (10)

A cylindrical fixing film;
A heating element that is disposed inside the fixing film and is long in the axial direction of the cylindrical fixing film;
A nip member arranged to contact the inner surface of the fixing film;
A fixing device comprising a backup member that forms a nip portion with the fixing film by sandwiching the fixing film with the nip member;
A pair of first support members disposed on both ends of the heating element in the axial direction and integrally supporting the heating element and the nip member;
A second support member that movably supports the pair of first support members so that the nip member moves relative to the backup member;
A stay that is long in the axial direction of the cylindrical fixing film and supports the nip member from the opposite side of the nip portion ;
The stay is fixed to the first support member;
The nip member is fixed to the stay;
The fixing device, wherein the heating element is fixed to the first support member.   The fixing device according to claim 1, wherein the second support member supports the backup member. A reflecting plate for reflecting the radiant heat from the heating element to the nip member,
The reflector fixing device according to claim 1 or claim 2, characterized in that it is supported lifting the pair of the first supporting member. 2. The second support member is configured to support the pair of first support members movably along a facing direction in which the nip member and the backup member are opposed to each other. The fixing device according to claim 3. The second support member has a pair of grooves extending in the facing direction,
  The fixing device according to claim 4, wherein the pair of first support members are slidably supported by the pair of grooves.   The fixing device according to claim 1, wherein the heating element is a halogen lamp.   The fixing device according to claim 1, wherein the heating element is disposed at a distance from the nip member.   The fixing device according to claim 1, wherein the nip member is a plate-like member.   A recess is formed in each of the pair of first support members,
  The stay is formed in a substantially U shape in sectional view,
  The both ends of the stay in the axial direction are fitted in the recesses formed in the pair of first support members, respectively. Fixing device.   The fixing device according to claim 1, further comprising a screw for fastening both end portions of the heating element to the pair of first support members.

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