JP6269070B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a fixing device and an image forming apparatus for thermally fixing a developer image on a recording sheet.

  2. Description of the Related Art Conventionally, a fixing device including a cylindrical heating roller, a heater that is disposed inside the heating roller and has one end protruding from the opening of the heating roller, and a fixing frame that supports a terminal provided at one end of the heater. Is known (see, for example, Patent Document 1).

JP 2007-57644 A

  By the way, in the conventional technology, there is a risk that the heating efficiency of the heating roller may be reduced due to the outside air entering the heating roller through the opening of the heating roller or the air inside the heating roller flowing out through the opening. was there.

  SUMMARY An advantage of some aspects of the invention is that it provides a fixing device and an image forming apparatus capable of improving the heating efficiency of a heating roller.

In order to solve the above problems, a fixing device according to the present invention is provided with a heating roller, a heater disposed inside the heating roller and having one end protruding from an opening of the heating roller, and one end of the heater. A terminal cover that covers at least a part of the terminal to be provided.
The terminal cover covers at least a part of the terminal, and protrudes from the cover part in a direction intersecting the axial direction along the axis of the heating roller to cover at least a part of the opening of the heating roller. And a protruding wall.

  According to this configuration, since the outside air can flow into the heating roller from the opening of the heating roller, or the air in the heating roller can be prevented from flowing out through the opening by the protruding wall. The heating efficiency of the heating roller can be improved.

  Further, in the above-described configuration, a roller gear provided at one end of the heating roller is provided, and the roller gear overlaps with the opening of the heating roller when viewed from the axial direction, and has a through hole communicating with the inside of the heating roller. And the protruding wall may be configured to cover at least a part of the through hole of the roller gear.

  According to this, since the protruding wall covers at least a part of the through hole of the roller gear, external air flows into the heating roller from the opening of the heating roller through the through hole of the roller gear, or inside the heating roller. The protruding wall can suppress the outflow of air through the opening and the through hole.

  In the above-described configuration, when the fixing frame that supports the terminal of the heater is provided, at least a part of the through hole of the roller gear may be covered with the protruding wall and the fixing frame. .

  According to this, the through hole of the roller gear can be satisfactorily covered by the protruding wall and the fixing frame.

  In the above-described configuration, all of the through holes of the roller gear may be covered with the protruding wall, the cover portion, and the fixing frame when viewed from the axial direction.

  According to this, it is possible to further suppress the outside air from flowing into the heating roller from the through hole of the roller gear or the air inside the heating roller from flowing out of the through hole of the roller gear. Therefore, the heating efficiency of the heating roller can be further improved.

  In the above-described configuration, the terminal cover may be fixed to the fixing frame.

  Further, in the above-described configuration, the protruding wall can be configured to protrude from the cover portion toward the side opposite to the fixing frame.

  Further, in the above-described configuration, the protruding wall may be disposed at an interval in the axial direction with respect to the roller gear.

  According to this, since the protruding wall is disposed with an interval in the axial direction with respect to the roller gear, it is possible to suppress the roller gear from interfering with the protruding wall and being damaged.

In addition, an image forming apparatus according to the present invention includes the above-described fixing device, a main body frame that supports the fixing device, and an exhaust fan that exhausts air in the main body frame to the outside.
The fixing frame includes glass and PET.
The protruding wall is disposed on the opposite side of the exhaust fan with the heating roller interposed therebetween.

  According to this configuration, since the air flow is generated in the heating roller by the exhaust fan can be suppressed by the protruding wall, the heated air in the heating roller flows to the exhaust fan side by the exhaust fan. It is possible to suppress the generation of UFP (Ultra Fine Particles) from the portion on the exhaust fan side of the heater.

  According to the present invention, the heating efficiency of the heating roller can be improved.

1 is a cross-sectional view illustrating a laser printer according to an embodiment of the present invention. FIG. 3 is an exploded perspective view of the disassembled fixing device as viewed from below. It is an expansion perspective view which shows the structure around a terminal cover. It is the bottom view which looked at the structure around the terminal attachment surface of a fixing frame from the lower side. FIG. 2A is a perspective view illustrating a relationship between a through hole of a roller gear, a terminal cover, and a fixing frame; FIG. 3A illustrates a state in which the terminal cover is removed from the fixing frame, and FIG. b). It is the front view which looked at the roller gear and the terminal cover from the front side. FIG. 6 is a bottom view of the structure around the terminal cover of the fixing device as viewed from below. FIG. 3 is a diagram illustrating a positional relationship between an exhaust fan and a fixing device.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of a laser printer as an example of an image forming apparatus will be briefly described, and then the characteristic part of the present invention will be described in detail.

  In the following description, the direction will be described with reference to the user when using the laser printer. That is, in FIG. 1, the right side toward the paper surface is “front side”, the left side toward the paper surface is “rear side”, the front side toward the paper surface is “left side”, and the rear side toward the paper surface is “right side”. To do. In addition, the vertical direction toward the page is defined as the “vertical direction”.

  As shown in FIG. 1, the laser printer 1 includes a feeder unit 4 for feeding paper 3 and an image forming unit 5 for forming an image on the fed paper 3 in a main body frame 2. I have.

  The feeder unit 4 includes a paper feed tray 6 that is detachably mounted on the bottom of the main body frame 2 and a paper pressing plate 7 provided in the paper feed tray 6. The feeder unit 4 includes a paper feed roller 8 and a paper feed pad 9 provided on the upper front side of the paper feed tray 6, and a paper dust removing roller 10 provided downstream of the paper feed roller 8 in the conveyance direction of the paper 3. , 11 are provided. Furthermore, the feeder unit 4 includes a registration roller 12 provided on the downstream side with respect to the paper dust removing roller 11.

  In the feeder unit 4 configured as described above, the sheet 3 in the sheet feeding tray 6 is brought close to the sheet feeding roller 8 side by the sheet pressing plate 7, and one sheet is fed by the sheet feeding roller 8 and the sheet feeding pad 9. The paper is separated and sent out, passes through various rollers 10 to 12 so as to make a U-turn on the front side of the main body frame 2, and is conveyed from the front side to the rear side of the main body frame 2 to the image forming unit 5.

  The image forming unit 5 includes a scanner unit 16, a process cartridge 17, and a fixing device 18.

  The scanner unit 16 is provided at an upper portion in the main body frame 2 and includes a laser light emitting unit (not shown), a polygon mirror 19 that is rotationally driven, lenses 20, 21 and reflecting mirrors 22, 23, 24, and the like. . In the scanner unit 16, the laser beam is irradiated on the surface of the photosensitive drum 27 of the process cartridge 17 by high-speed scanning through a path indicated by a chain line in the drawing.

  The process cartridge 17 is disposed below the scanner unit 16 and is detachable from the main body frame 2. The process cartridge 17 is mainly composed of a developing cartridge 28 and a drum unit 51.

  The developing cartridge 28 includes a developing roller 31, a layer thickness regulating blade 32, a supply roller 33, and a toner hopper 34. The toner in the toner hopper 34 is stirred by an agitator (not shown) and then supplied to the developing roller 31 by the supply roller 33. At this time, the toner is positively frictionally charged between the supply roller 33 and the developing roller 31. The The toner supplied onto the developing roller 31 enters between the layer thickness regulating blade 32 and the developing roller 31 as the developing roller 31 rotates, and is carried on the developing roller 31 as a thin layer having a constant thickness. The

  The drum unit 51 includes a photosensitive drum 27, a scorotron charger 29, and a transfer roller 30. In the drum unit 51, the surface of the photosensitive drum 27 is uniformly positively charged by the scorotron charger 29 and then exposed by high-speed scanning of the laser beam from the scanner unit 16. Thereby, the potential of the exposed part is lowered, and an electrostatic latent image based on the image data is formed.

  Next, the rotation of the developing roller 31 causes the toner carried on the developing roller 31 to be supplied to an electrostatic latent image formed on the surface of the photosensitive drum 27 when it contacts and faces the photosensitive drum 27. The The toner is visualized by being selectively carried on the surface of the photosensitive drum 27, whereby a toner image is formed by reversal development. Thereafter, the sheet 3 is conveyed between the photosensitive drum 27 and the transfer roller 30, whereby the toner image carried on the surface of the photosensitive drum 27 is transferred onto the sheet 3.

  The fixing device 18 is supported by the main body frame 2 and includes a heating roller 41 including a halogen lamp 60 therein, a pressure roller 42 disposed below the heating roller 41 and pressed against the heating roller 41. It has. In the fixing device 18, the heating roller 41 is heated by the halogen lamp 60, so that the toner image transferred onto the sheet 3 while the sheet 3 passes between the heating roller 41 and the pressure roller 42. Is heat-fixed.

  Thereafter, the sheet 3 is conveyed to the sheet discharge path 44 by the conveying roller 43 and discharged onto the sheet discharge tray 46 by the sheet discharge roller 45.

Next, the structure of the fixing device 18 will be described in detail.
As shown in FIG. 2, the fixing device 18 includes the halogen lamp 60 and the heating roller 41 described above, and also includes a fixing frame 100 that supports them.

  The heating roller 41 is a metal member formed in a cylindrical shape that is long in the left-right direction, and both end portions thereof are rotatably supported by two bearings 71 and 72 supported by the fixing frame 100. It is rotatable about an axis AL that extends in the left-right direction. A roller gear 80 that rotates integrally with the heating roller 41 is provided at the left end of the heating roller 41.

  The roller gear 80 is a resin gear, and a driving force of a motor (not shown) provided in the main body frame 2 is transmitted through a plurality of gears. As a result, the heating roller 41 is rotated by the driving force of the motor.

  A through hole 81 that penetrates in the left-right direction and communicates with the inside of the heating roller 41 is formed in the center portion of the roller gear 80 so as to overlap the opening 41A (only the right side is shown) of the heating roller 41 when viewed from the left-right direction. Yes. As a result, the left end portion (left terminal 63 described later) of the halogen lamp 60 inserted into the heating roller 41 passes outside the end surface on the outer side in the horizontal direction of the roller gear 80 through the opening 41A and the through hole 81 of the heating roller 41. It can be projected. The through hole 81 has a smaller diameter than the opening 41 </ b> A on the left end side of the heating roller 41.

  Further, the left end portion of the heating roller 41 is provided with a ring member 200 arranged away from the roller gear 80 inward in the left-right direction, and a regulation wire (not shown) arranged inside in the left-right direction of the ring member 200. Yes. The ring member 200 is formed in an annular shape surrounding the outer peripheral surface of the heating roller 41, and is attached to the outer peripheral surface of the heating roller 41 so as to be movable in the left-right direction.

  The regulation wire is a member that regulates the movement of the ring member 200 in the left-right direction, and is fixed to the heating roller 41 by engaging both ends with holes formed in the heating roller 41. A portion of the heating roller 41 between the ring member 200 and the roller gear 80 is rotatably supported by the bearing 72 described above.

  That is, the ring member 200 and the roller gear 80 can abut on the bearing 72 disposed therebetween in the left-right direction. Thereby, when the heating roller 41 moves in the axial direction, the ring member 200 or the roller gear 80 abuts on the bearing 72, so that the heating roller 41 can be prevented from moving too much in the axial direction. ing.

  The halogen lamp 60 is a heater configured to generate heat when energized, and includes a glass tube 61, a filament 62 provided in the glass tube 61, and a filament 62 protruding outward in the left-right direction from both ends of the glass tube 61. Two terminals 63 and 64 connected to both ends 62A and 62B are provided. The glass tube 61 has a cylindrical cylindrical portion 61A that is long in the left-right direction, and a pair of sealing portions 61B that are integrally formed at both ends of the cylindrical portion 61A.

  Each terminal 63, 64 is formed in a plate shape orthogonal to the vertical direction. When the halogen lamp 60 is disposed in the heating roller 41, the right terminal 64 protrudes outward in the left-right direction from the right opening 41A of the heating roller 41, and the left terminal 63 extends from the through hole 81 of the roller gear 80. It is configured to project outward in the left-right direction (see FIG. 8).

  On the front side of the left terminal 63, an engagement hole 63A that engages with an engagement projection 111 (described later) formed on the fixing frame 100 is formed, and on the rear side, a screw S1 (refer to FIG. 6). ) Is formed in a circular hole shape. Further, the right terminal 64 is formed with an insertion hole 64A through which the screw S1 is inserted in a long hole shape that is long in the left-right direction.

  The terminals 63 and 64 are fixed to the fixing frame 100 by screws S1 and connected to a power connector (not shown). A terminal cover 90 is provided under the left terminal 63 so as to cover it.

  3 and 4, the fixing frame 100 is a frame including glass and PET (Polyethylene terephthalate), and includes a terminal mounting surface 110 for mounting the terminal 63 on the left side of the halogen lamp 60. The first support wall 121 and the second support wall 122 projecting downward (upward in the figure: the pressure roller 42 side) from the right end of the terminal mounting surface 110, and from the front end of the terminal mounting surface 110 And a mounting boss portion 123 protruding downward.

  The terminal mounting surface 110 is a flat surface that comes into contact with the surface of the terminal 63, and an engagement protrusion 111 that can be engaged with the engagement hole 63 </ b> A of the terminal 63 is formed on the front side thereof so as to protrude downward. A mounting hole 112 into which a screw S1 (see FIG. 6) for mounting the terminal 63 is screwed is formed. Accordingly, when the terminal 63 is fixed to the terminal mounting surface 110, the halogen lamp 60 is moved in the front-rear and left-right directions with respect to the fixing frame 100 by engaging the engagement hole 63 A of the terminal 63 with the engagement protrusion 111. Positioned. After the halogen lamp 60 is positioned, the terminal 63 is fixed to the fixing frame 100 by screwing the screw S1 into the mounting hole 112 while passing the screw S1 through the insertion hole 63B of the terminal 63. The right terminal 64 is also fixed to the fixing frame 100 by the screw S1.

  The first support wall 121 and the second support wall 122 are arranged with a slight gap in the front-rear direction. One end 62 </ b> A of the filament 62 is disposed between the first support wall 121 and the second support wall 122.

  The front end of the first support wall 121 is provided with a first surface 121A extending in a direction perpendicular to the terminal mounting surface 110, and a first inclined surface 121B extending rearward and obliquely downward from the lower end of the first surface 121A. Yes. The rear end of the second support wall 122 is provided with a second surface 122A that faces the first surface 121A in the front-rear direction, and a second inclined surface 122B that extends obliquely downward from the lower end of the second surface 122A. ing.

  As a result, the one end portion 62A of the filament 62 can be smoothly guided between the first surface 121A and the second surface 122A by the inclined surfaces 121B and 122B.

  The mounting boss portion 123 is integrally formed adjacent to the left side of the second support wall 122, and a screw S2 (see FIG. 5B) for mounting the terminal cover 90 is screwed into the proper position. A mounting hole 123A is formed. The lower surfaces of the first support wall 121, the second support wall 122, and the mounting boss portion 123 are formed flush with each other and form a flat cover mounting surface 124 for mounting the terminal cover 90.

  A first engagement wall 130 is formed at the left end of the terminal mounting surface 110 so as to protrude downward from the terminal mounting surface 110, specifically, to protrude downward from the cover mounting surface 124. On the rear end side of the first engagement wall 130, a first engagement surface 131 that can be engaged with a first engagement piece 93 on the rear side of the terminal cover 90 described later, and a lower end of the first engagement surface 131. A third inclined surface 132 is provided that is inclined downward and forward.

  On the front end side of the first engagement wall 130, a second engagement surface 133 that can be engaged with a second engagement piece 94 on the front side of the terminal cover 90 to be described later, and obliquely downward from the lower end of the second engagement surface 133 A fourth inclined surface 134 that is inclined rearward is provided. Thus, the engaging pieces 93 and 94 of the terminal cover 90 can be smoothly guided to the engaging surfaces 131 and 133 by the inclined surfaces 132 and 134, respectively.

  Further, a second engagement wall 140 and a third engagement wall 150 projecting downward from the cover attachment surface 124 are provided on the front end side of the cover attachment surface 124. The second engagement wall 140 is disposed on the front side of the first engagement wall 130 and is arranged so as to be arranged with a space in the front-rear direction with respect to the first engagement wall 130.

  On the rear end side of the second engagement wall 140, a third engagement surface 141 that can be engaged with the second engagement piece 94 on the front side of the terminal cover 90, and a lower oblique front from the lower end of the third engagement surface 141 And a fifth inclined surface 142 that is inclined toward the surface. Accordingly, the second engagement piece 94 on the front side of the terminal cover 90 is smoothly interposed between the third engagement surface 141 and the second engagement surface 133 by the fifth inclined surface 142 and the fourth inclined surface 134. It is possible to guide.

  The third engagement wall 150 is a wall that engages with an engagement recess 91 </ b> A of the terminal cover 90, which will be described later, and is disposed on the right side of the second engagement wall 140 and in the left-right direction with respect to the second engagement wall 140. Are arranged so as to be spaced apart from each other. The third engagement wall 150 is inclined toward the inside of the third engagement wall 150 from the three fourth engagement surfaces 151 that can be engaged with the engagement recesses 91 </ b> A and the lower ends of the respective fourth engagement surfaces 151. Three sixth inclined surfaces 152. Thereby, the engaging recess 91 </ b> A of the terminal cover 90 can be smoothly guided to the fourth engaging surfaces 151 by the sixth inclined surfaces 152.

  The terminal cover 90 is a resin member. The terminal cover 90 covers the terminal 63 and the right end portion of the cover portion 91 is directed downward (in a direction perpendicular to the axis AL, specifically on the side opposite to the fixing frame 100). And a protruding wall 92 that protrudes. The cover portion 91 is formed in a substantially flat plate shape having a size covering the entire terminal 63, and has a first engagement piece 93 and a second engagement projecting from the left end portion toward the left side at the left end portion. A piece 94 is formed.

  The first engagement piece 93 and the second engagement piece 94 are disposed at positions where the first engagement wall 130 can be sandwiched in the front-rear direction when the terminal cover 90 is attached to the fixing frame 100. The second engagement piece 94 is formed in a size that can enter between the first engagement wall 130 and the second engagement wall 140. As a result, the first engagement piece 93 and the second engagement piece 94 can be engaged with the first engagement wall 130 and the second engagement wall 140 in the front-rear direction, so that the terminal cover 90 is positioned in the front-rear direction. (See FIG. 7).

  Further, all the corners of the first engagement piece 93 and the second engagement piece 94 are gentle surfaces having a circular arc shape in cross section. Thereby, each engagement piece 93, 94 can be smoothly engaged with each engagement wall 130, 140.

  An engagement recess 91 </ b> A that is recessed rearward is formed at the front end portion of the cover portion 91. The engagement recess 91 </ b> A is formed to have a size that can be engaged with each of the fourth engagement surfaces 151 of the third engagement wall 150 described above. Thereby, since the engaging recess 91A engages with the third engaging wall 150 in the front-rear and left-right directions, the terminal cover 90 can be positioned in the front-rear and left-right directions (see FIG. 7). .

  In addition, all the corners of the engaging recess 91A are gentle surfaces having a circular arc shape in cross section. Thereby, the engagement recess 91 </ b> A can be smoothly engaged with the third engagement wall 150.

  An insertion hole 91 </ b> B for inserting the screw S <b> 2 (see FIG. 7) is formed on the front end side of the cover portion 91 so as to penetrate in the vertical direction. Accordingly, the terminal cover 90 is fixed to the cover mounting surface 124 by screwing the screw S2 into the mounting hole 123A of the mounting boss portion 123 while inserting the screw S2 into the insertion hole 91B. .

  At the rear end of the cover portion 91, there are provided an inclined wall 91C that is inclined upward and obliquely rearward from the rear end, and an extending wall 91D that extends rearward from the rear end of the inclined wall 91C. At the corner between the cover portion 91 and the protruding wall 92, two reinforcing ribs 95 having a triangular shape in cross-section and connecting the cover portion 91 and the protruding wall 92 are provided in the front-rear direction.

  The protruding wall 92 is formed in a substantially trapezoidal shape when viewed from the left-right direction, and protrudes from the surface of the cover portion 91 that contacts the head of the screw S2. The lower end surface of the projecting wall 92 has a top surface 92C extending substantially in the front-rear direction, a tapered surface 92A extending so as to incline obliquely upward from the front end of the top surface 92C, and obliquely upward from the rear end of the top surface 92C. It becomes the taper surface 92B extended so that it may incline.

  The length X1 of the protruding wall 92 in the front-rear direction is larger than the diameter of the through hole 81 of the roller gear 80 (the opening 41A of the heating roller 41). The vertical length X2 of the protruding wall 92 is larger than ½ of the radius of the through hole 81 of the roller gear 80 (the opening 41A of the heating roller 41).

  As shown in FIGS. 5A and 5B, the protruding wall 92 is configured to cover the lower portion of the through hole 81 of the roller gear 80. In other words, the protruding wall 92 covers a part of the opening 41 </ b> A on the left side of the heating roller 41 through the through hole 81.

  Specifically, the protruding wall 92 has a portion that overlaps the through hole 81 when viewed from the left-right direction, and a portion that extends from the portion to the outer side in the radial direction than the periphery of the through hole 81. Further, portions other than the lower portion of the through hole 81 described above are also covered with the end surface on the inner side in the left-right direction of the cover portion 91 and the fixing frame 100.

  As shown in FIGS. 4 to 7, the fixing frame 100 is provided with a facing surface 101 that is disposed outside the roller gear 80 in the left-right direction and faces the roller gear 80 in the left-right direction. The opposing surface 101 has a first interval L1 in the left-right direction with respect to the roller gear 80 (shortest distance), and overlaps a part of the through hole 81 of the roller gear 80 when viewed from the left-right direction. Specifically, the opposed surface 101 faces the roller gear 80 when the heating roller 41 is moved to the leftmost side, that is, the roller gear 80 in a state where the ring member 200 and the bearing 72 are in contact with each other with a first interval L1. Yes.

  The protruding wall 92 and the cover portion 91 are opposed to the roller gear 80 in the left-right direction with a second interval L2 smaller than the first interval L1, and the other part of the through hole 81 of the roller gear 80 is viewed from the left-right direction. It overlaps with. Specifically, the protruding wall 92 and the cover portion 91 leave a second interval L2 with respect to the roller gear 80 when the heating roller 41 is moved to the leftmost side, that is, the roller gear 80 in a state where the ring member 200 and the bearing 72 are in contact with each other. Facing each other.

  Here, the first interval L1 and the second interval L2 are appropriately set in consideration of air flowing into the heating roller 41 and interference between the roller gear 80 and the facing surface 101 or the protruding wall 92. be able to. For example, the first interval L1 is 1.200 mm, and the second interval L2 is 1.025 mm. The first distance L1 may be, for example, 0.2 mm to 5.1 mm, 0.6 mm to 3.1 mm, or 1.0 mm to 1.6 mm. . Further, the second distance L2 may be, for example, 0.1 mm to 5.0 mm, 0.5 mm to 3.0 mm, or 0.9 mm to 1.5 mm. In addition, the numerical range mentioned above is an example, and the numerical value of each space | interval L1, L2 is not restricted to the numerical range mentioned above.

  Thus, by covering the through hole 81 with the protruding wall 92, the cover portion 91, and the facing surface 101 close to the roller gear 80, external air flows into the heating roller 41 through the through hole 81, It is possible to suppress the air in the roller 41 from flowing out through the right opening 41A. In the present embodiment, a notch (a portion between the first support wall 121 and the second support wall 122) is formed in the upper portion of the facing surface 101, so that the protruding wall 92, the cover portion 91, and the facing surface are formed. 101 does not cover all of the through holes 81, but the present invention is not limited to this. For example, a new projecting wall projecting upward from the cover portion 91 is provided, and the projecting wall is formed into a shape that fits into the gap between the first support wall 121 and the second support wall 122. All of the through holes 81 may be covered with the new protruding wall, the protruding wall 92, the cover portion 91, and the facing surface 101. Note that the protruding wall, the cover portion, and the fixing frame may not be configured to cover all of the through holes as viewed from the axial direction, and may be configured to cover 90% or more of the through holes. And it may be comprised so that 80% or more of a through-hole may be covered, and it may be comprised so that 70% or more of a through-hole may be covered.

  As shown in FIG. 8, an exhaust fan 300 for discharging the air in the main body frame 2 to the outside is provided on the right side wall 2A of the main body frame 2 (on the side opposite to the terminal cover 90 with the heating roller 41 interposed therebetween). Is provided. In FIG. 8, for convenience, the heating roller 41 is illustrated as a cross-sectional view taken along a plane including the axis AL, and the gear teeth of the roller gear 80 are omitted.

  In the laser printer 1 configured as described above, when the exhaust fan 300 is driven, the air in the heating roller 41 is likely to be sucked into the exhaust fan 300, but on the opposite side of the heating roller 41 from the exhaust fan 300. Since the through hole 81 of the roller gear 80 provided is covered with the fixing frame 100, the protruding wall 92 of the terminal cover 90, and the cover portion 91, it is possible to suppress the occurrence of airflow in the heating roller 41. Therefore, it is possible to prevent cold air from flowing into the heating roller 41 through the through-hole 81 and heated air in the heating roller 41 from flowing out through the opening 41A on the right side of the heating roller 41. Therefore, the heating efficiency of the heating roller 41 can be improved.

  In addition, by suppressing the occurrence of air flow in the heating roller 41 by the protruding wall 92 or the like, the heated air in the heating roller 41 flows to the exhaust fan 300 side by the exhaust fan 300, thereby fixing frame. It is possible to suppress the occurrence of UFP (Ultra Fine Particles) from the portion of the 100 exhaust fan 300 side being heated.

As described above, according to the present embodiment, the following effects can be obtained in addition to the effects described above.
Since the protruding wall 92 is disposed with a gap in the left-right direction with respect to the roller gear 80, the roller gear 80 can be prevented from interfering with the protruding wall 92 and being damaged.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the above embodiment, a part of the through hole 81 of the roller gear 80 is covered with the protruding wall 92, but the present invention is not limited to this. For example, at least the opening 41A on the right side of the heating roller 41 in the above embodiment You may comprise so that a part may be covered with the protrusion wall of a terminal cover. Moreover, you may comprise so that all the openings of a heating roller or all the openings of a roller gear may be covered with a protrusion wall.

  In the embodiment, the terminal cover 90 covers the entire terminal 63. However, the present invention is not limited to this, and the terminal cover only needs to be configured to cover at least a part of the terminal.

  In the embodiment, the halogen lamp 60 is exemplified as the heater, but the present invention is not limited to this, and the heater may be a carbon heater, for example.

  In the embodiment, the exhaust fan 300 is provided on the side opposite to the protruding wall 92 with the heating roller 41 interposed therebetween. However, the present invention is not limited to this, and the exhaust fan is on the same side as the protruding wall with respect to the heating roller. You may arrange in. Even in this case, since the air in the heating roller can be prevented from flowing out through the through hole of the roller gear by the protruding wall or the like, the heating efficiency of the heating roller can be improved.

  In the above embodiment, the present invention is applied to the laser printer 1. However, the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.

  In the said embodiment, although the protrusion wall 92 was protruded in the direction orthogonal to the axis line AL, this invention is not limited to this, The protrusion wall should just protrude in the direction which cross | intersects an axial direction.

18 Fixing Device 41 Heating Roller 41A Opening 60 Halogen Lamp 63 Terminal 80 Roller Gear 81 Through Hole 90 Terminal Cover 91 Cover Portion 92 Projecting Wall AL Axis

Claims (15)

A heating roller;
A heater disposed inside the heating roller and having one end protruding from the opening of the heating roller;
A fixing frame that supports a terminal provided at the one end of the heater;
A fixing device and a terminal cover covering at least a portion of said end terminal of the heater,
The terminal cover covers at least a part of the terminal, and protrudes from the cover part in a direction intersecting the axial direction along the axis of the heating roller to cover at least a part of the opening of the heating roller. have a and the protruding wall,
The fixing frame has a facing surface facing the roller gear provided at the one end of the heating roller in the axial direction;
The fixing device , wherein the protruding wall is closer to the roller gear than the facing surface in the axial direction .   The fixing device according to claim 1, wherein the terminal cover is disposed apart from the terminal. The fixing frame is
A terminal mounting surface in contact with the terminal of the heater;
The fixing device according to claim 2, further comprising a first support wall that protrudes from the one end portion of the heater from the terminal mounting surface and supports the terminal cover. The fixing frame further includes a second support wall that protrudes from the terminal mounting surface than the one end of the heater and supports the terminal cover.
The fixing device according to claim 3, wherein the one end portion of the heater is disposed between the first support wall and the second support wall. A first screw for fixing the terminal to the fixing frame;
The terminal is plate-shaped,
The terminal is formed with an insertion hole through which the first screw is inserted,
The fixing device according to claim 1, wherein the cover portion of the terminal cover covers the first screw. A second screw for fixing the terminal cover to the fixing frame;
The fixing device according to claim 1, wherein the terminal cover is formed with an insertion hole through which the second screw is inserted. The fixing frame has a boss portion that protrudes from a terminal mounting surface that contacts the terminal of the heater and has a cover mounting surface to which the terminal cover is mounted,
The fixing device according to claim 6, wherein a hole into which the second screw is screwed is formed in the boss portion. Before Symbol roller gear overlaps when viewed from the axial direction to the opening of the heating roller has a through hole communicating with the interior of the heating roller,
The fixing device according to claim 1, wherein the protruding wall covers at least a part of the through hole of the roller gear. The fixing device according to claim 8 , wherein the protruding wall of the terminal cover is longer than the diameter of the through hole of the roller gear in a direction orthogonal to the axial direction and a direction in which the protruding wall protrudes. The fixing device according to claim 8 , wherein at least a part of the through hole of the roller gear is covered with the protruding wall and the fixing frame. 11. The fixing device according to claim 10 , wherein all of the through holes of the roller gear are covered with the protruding wall, the cover portion, and the fixing frame when viewed from the axial direction. The terminal cover fixing device according to claim 10 or claim 11, characterized in that it is fixed to the fixing frame. The fixing device according to claim 12 , wherein the protruding wall protrudes from the cover portion toward a side opposite to the fixing frame. The protruding wall, the fixing device according to any one of claims 13 claim 1, characterized in that they are spaced in the axial direction with respect to the roller gear. The fixing device according to any one of claims 1 to 14 ,
A main body frame for supporting the fixing device;
An image forming apparatus comprising: an exhaust fan for exhausting air in the main body frame to the outside,
The fixing frame includes glass and PET,
The image forming apparatus, wherein the protruding wall is disposed on the opposite side of the exhaust fan across the heating roller.

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