JP2019035867A - Fixing apparatus - Google Patents

Abstract

To provide a fixing apparatus that can improve a degree of freedom of design of a heater end part.SOLUTION: A fixing apparatus 100 comprises: a heating part 110 that heats a sheet 3; heaters that are the heaters (a first heater 120 and a second heater 130) which heat the heating part 110 and that have heater main body parts (a first glass tube 121 and a second glass tube 131) which extend in a first direction, and lead pins (a first lead pin 122 and a second lead pin 132) which protrude from end surfaces of the heater main body parts in the first direction; a terminal board to which the lead pin is fixed; and a frame (fixing frame 160) that supports the terminal board. The terminal board has a tabular main body part 171 that is supported on the frame, and a connection part 172 that extends from the main body part 171 in a direction intersecting with the main body part 171. The connection part 172 extends from an edge of a heater main body part side of the main body part 171.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a fixing device including a heater.

  Conventionally, a fixing device provided in an image forming apparatus is known which includes a heater. For example, in the fixing device disclosed in Patent Document 1, the lead wire at the end of the heater is fixed to the terminal board. The connecting portion for connecting the connector to the terminal plate extends from the edge of the terminal plate in the direction orthogonal to the longitudinal direction of the heater.

JP 2010-80150 A

  However, in the technique of Patent Document 1, since the connection portion extends from the end portion of the terminal board in the direction orthogonal to the longitudinal direction of the heater, there is a problem that the degree of freedom in designing the heater end portion is reduced. is there.

  SUMMARY An advantage of some aspects of the invention is that it provides a fixing device capable of improving the degree of freedom in designing the heater end.

In order to achieve the above-described object, a fixing device of the present invention includes a heating unit that heats a sheet, a heater that heats the heating unit, a heater main body that extends in a first direction, and a heater main body in the first direction. The heater includes a lead pin protruding from the end face of the terminal, a terminal plate to which the lead pin is fixed, and a frame that supports the terminal plate.
The terminal board has a plate-like main body portion supported by the frame and a connection portion extending from the main body portion in a direction crossing the main body portion. The connecting portion extends from the edge of the main body on the heater main body side.

  According to the fixing device configured as described above, the size in the first direction, that is, the longitudinal direction of the heater can be reduced, so that the degree of freedom in design can be improved. For this reason, for example, the end of the fixing device can be designed to be compact, and the fixing device can be easily attached and detached.

  ADVANTAGE OF THE INVENTION According to this invention, the freedom degree of design around a heater edge part can be improved.

1 is a diagram illustrating a schematic configuration of a laser printer including a fixing device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of the fixing device viewed from below. It is the perspective view (a) which shows the left end part and roller gear of a heating part, and the side view which looked at the roller gear from the left. They are the perspective view (a) which shows a 1st terminal board, and the figure (b) which looked at the 1st terminal board from the right. FIG. 3 is an enlarged cross-sectional view of the vicinity of the left end portion of the fixing device as viewed from below. It is a figure which shows the positional relationship of a drive gear, a roller gear, and a 1st terminal board. It is a disassembled perspective view which shows a control member, a 1st terminal board, and a fixing frame. It is a perspective view when a regulating member and a first terminal board are arranged on the fixing frame. FIG. 4 is a side view (a) showing a left end portion of a fixing frame in the prior art and a side view (b) showing a left end portion of the fixing frame of the present invention. It is a perspective view which shows the 1st terminal board in a modification.

  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 the laser printer provided with the fixing device 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, a laser printer 1 which is an electrophotographic image forming apparatus forms a feeder unit 4 for supplying a sheet 3 and an image on the supplied sheet 3 in a main body frame 2. The image forming unit 5 is provided.

  The main body frame 2 has a mounting portion 2A at the rear. The main body frame 2 has a rear cover 2B that is rotatable about a lower end portion, and the mounting portion 2A is exposed by opening the rear cover 2B.

  The feeder unit 4 includes a sheet tray 6 that is detachably attached to the bottom of the main body frame 2, and a pressing plate 7 provided in the sheet tray 6. Further, the feeder unit 4 includes a pickup roller 8 and a separation pad 9 provided on the upper front side of the sheet tray 6, and powder removing rollers 10 and 11 provided on the downstream side in the sheet 3 conveyance direction with respect to the pickup roller 8. Yes. Further, the feeder unit 4 includes a registration roller 12 provided on the downstream side with respect to the powder removing roller 11.

  In the feeder unit 4 configured as described above, the sheets 3 in the sheet tray 6 are brought close to the pickup roller 8 by the pressing plate 7 and separated one by one by the pickup roller 8 and the separation pad 9. It is 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 100.

  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 charged by the scorotron charger 29 and then exposed by high-speed scanning of the laser beam from the scanner unit 16. Thereby, 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 sheet 3 to which the toner image has been transferred is thermally fixed by the fixing device 100, and is then conveyed to the discharge unit 44 by the conveyance roller 43 and discharged onto the stacking tray 46 by the discharge roller 45.

  The fixing device 100 is a hollow roller that rotates about a rotation axis G that extends in the left-right direction, a heating unit 110 that heats the sheet 3, and a first heater that is an example of a heater disposed inside the heating unit 110. 120 and the second heater 130, a pressure unit 140 that is a roller disposed below the heating unit 110 and pressed against the heating unit 110, and a resin-made fixing frame 160 as an example of a frame. In preparation. The fixing device 100 is mounted on the mounting portion 2A of the main body frame 2 from the rear side. In the fixing device 100, the heating unit 110 is heated by the first heater 120 and the second heater 130, so that the sheet 3 passes between the heating unit 110 and the pressing unit 140 from the front side toward the rear side. In the meantime, the toner image transferred onto the sheet 3 is thermally fixed.

  In the present embodiment, each of the first heater 120 and the second heater 130 is a halogen lamp configured to generate heat when energized, and heats the inner peripheral surface of the heating unit 110 by radiant heat. The first heater 120 and the second heater 130 extend in a direction along the rotation axis G of the heating unit 110 (hereinafter simply referred to as “first direction”). The first heater 120 and the second heater 130 are arranged side by side in the front-rear direction. Specifically, the first heater 120 is disposed on the front side of the second heater 130.

  As shown in FIG. 2, the heating unit 110 is rotatably supported by the fixing frame 160 via a bearing 161 fixed to the fixing frame 160. The heating unit 110 is a hollow roller having an opening 110A at the end, and has a cylindrical shape that extends long in the first direction. The heating unit 110 includes a roller body 111 and a roller gear 112 as an example of a gear at the left end. As shown in FIG. 3A, the roller main body 111 has a claw 111B for fixing the roller gear 112 to the left end.

  The roller gear 112 has a gear part 113, a wall part 114 extending radially inward from the gear part 113, and an opening hole 115 provided in the wall part 114. The roller gear 112 is engaged with a drive gear 166 disposed on the fixing frame 160 (see FIG. 6).

  As shown in FIG. 3B, the opening hole 115 has a circular hole 116 along a circular shape, and a groove portion 117 having a predetermined width H1 and recessed from the circular hole 116 radially outward. The claw portion 111 </ b> B of the roller main body portion 111 is engaged with the groove portion 117. The claw portion 111B is bent outward in the radial direction from the state shown in FIG. 3A after inserting the roller main body 111 into the roller gear 112, as shown in FIG. 3B.

  As shown in FIG. 2, the first heater 120 and the second heater 130 extend long in the first direction. In other words, the first direction is the longitudinal direction of the first heater 120 and the second heater 130. The first heater 120 includes a first glass tube 121 as an example of a heater body extending in the first direction, a first lead pin 122 protruding from the left end surface of the first glass tube 121, and a right side of the first glass tube 121. And a third lead pin 123 projecting from the end face. The second heater 130 includes a second glass tube 131 as an example of a heater body extending in the first direction, a second lead pin 132 protruding from the left end surface of the second glass tube 131, and a right side of the second glass tube 131. A fourth lead pin 133 protruding from the end face of the first lead pin 133.

  The respective leading end portions of the first lead pin 122 and the second lead pin 132 are fixed to and electrically connected to a first terminal plate 170 as an example of a terminal plate by welding or the like. The tip of the third lead pin 123 is fixed to the second terminal plate 180 by welding or the like and is conductive. The distal end portion of the fourth lead pin 133 is fixed to the third terminal plate 190 by welding or the like and is conductive. The first terminal board 170, the second terminal board 180 and the third terminal board 190 are supported by the fixing frame 160.

  An insulator 199 connecting the right end of the first glass tube 121 and the right end of the second glass tube 131 to the right end of the first glass tube 121 and the right end of the second glass tube 131. Is arranged. The insulator 199 has two holes penetrating in the first direction, and the right end of the first glass tube 121 and the right end of the second glass tube 131 pass through the hole.

  As shown in FIG. 4A, the first terminal plate 170 is made of a single metal plate, and extends in a direction intersecting the plate-like main body 171 and the surface 171B of the main body 171 from the main body 171. Connecting portion 172 to be connected.

  As shown in FIG. 5, the main body 171 is supported by the fixing frame 160. The first lead pin 122 and the second lead pin 132 are fixed to the main body 171. A first round hole 173 is disposed between the first lead pin 122 and the second lead pin 132 in the direction in which the first lead pin 122 and the second lead pin 132 are arranged. The first round hole 173 is an example of an engaging portion that engages with the fixing frame 160, and is located farther from the first glass tube 121 and the second glass tube 131 than the connection portion 172.

  The connection part 172 is a part connected to a connector such as a Faston terminal. The connector supplies power to the first heater 120 and the second heater 130. The connecting portion 172 extends from the edge 171A on the heater main body side of the main body portion 171, that is, the edge 171A on the first glass tube 121 side and the second glass tube 131 side in this embodiment. As shown in FIG. 4B, the direction D1 in which the connecting portion 172 extends is a perpendicular line D2 of the main body portion 171 as viewed from the first direction, specifically, the first lead pin 122 and the second second portion of the main body portion 171. The lead pin 132 is oblique to the perpendicular D2 of the surface 171B to which the lead pin 132 is fixed.

  As shown in FIG. 6, when viewed from the first direction, the direction D <b> 1 faces the side opposite to the side where the drive gear 166 is disposed with respect to the perpendicular D <b> 2 of the main body 171. In other words, the direction D1 is directed to avoid the drive gear 166.

  In addition, the smallest circle 177 including the first terminal board 170 when viewed from the first direction is smaller than the opening 110 </ b> A of the heating unit 110. In other words, the circumscribed circle of the first terminal plate 170 has a smaller diameter than the circle corresponding to the inner periphery of the opening 110A. Further, when viewed from the first direction, the smallest circle 177 including the first terminal board 170 is smaller than the opening hole 115 of the roller gear 112. Further, when viewed from the first direction, the dimension in the direction orthogonal to the extending direction D1 of the connecting portion 172 is smaller than the predetermined width H1 of the groove portion 117 of the roller gear 112.

  As shown in FIGS. 7 and 8, the first terminal board 170 is assembled to the end portion of the fixing frame 160 using the shielding member 270 and the regulating member 200. The fixing frame 160 includes a support surface 163 that supports the first terminal plate 170, a wall portion 162, an attachment portion 164 for fixing the restriction member 200, and a locking hole 165.

  The support surface 163 is a surface that supports the first terminal board 170. The support surface 163 is orthogonal to the vertical direction and faces downward. The support surface 163 has a rectangular hole 163A on the wall 162 side, and a first protrusion 163B that protrudes downward from the support surface 163 on the left side of the rectangular hole 163A. The first protrusion 163 </ b> B engages with the first round hole 173 of the main body portion 171 of the first terminal board 170 to position the first terminal board 170. The rectangular hole 163A is a hole through which the connecting portion 172 of the first terminal board 170 passes.

  The wall portion 162 is a plate-like wall orthogonal to the first direction, and is located between the first glass tube 121 and the second glass tube 131 and the first terminal plate 170. The wall 162 has a rectangular cutout 162A through which the first lead pin 122 and the second lead pin 132 pass.

  The notch 162A has a shielding member 270 that suppresses the radiant heat of the first heater 120 and the second heater 130 from leaking from the first glass tube 121 and the second glass tube 131 side of the wall portion 162 to the first terminal plate 170 side. Is arranged.

  The shielding member 270 has a rectangular plate shape that matches the notch 162A. The shielding member 270 is disposed between the four engaging protrusions 271 for engaging with the wall portion 162, the two first concave portions 272 disposed at the corner on the support surface 163 side, and the two first concave portions 272. Second recessed portion 273. The shielding member 270 is supported at the upper end by the support surface 163, and supported at the lower end by the regulating member 200, so that the movement in the vertical direction is restricted. When the engagement protrusion 271 engages with the wall portion 162, the engagement protrusion 271 is restricted from moving in the first direction. The first recess 272 is for the first lead pin 122 and the second lead pin 132 to pass through. The second recess 273 is for the lead pin of the heater to pass when only one heater is provided at a position between the first heater 120 and the second heater 130.

  The restriction member 200 includes a main body part 250, a first restriction part 210 and a second restriction part 220 that protrude from the main body part 250, a first fixing part 230, and a second fixing part 240. The first restricting portion 210 and the second restricting portion 220 are arranged at a predetermined distance from each other. The first fixing part 230 and the second fixing part 240 are arranged at both ends of the main body part 250 in the direction in which the first restricting part 210 and the second restricting part 220 are arranged.

  The restricting member 200 is fixed to the fixing frame 160 by the first fixing portion 230 entering the locking hole 165 of the fixing frame 160 and the second fixing portion 240 being fixed to the attachment portion 164 by screws or the like. When the restricting member 200 is fixed to the fixing frame 160, the first restricting portion 210 and the second restricting portion 220 come into contact with the first terminal plate 170 to restrict the first terminal plate 170 from coming off the fixing frame 160. It is like that.

According to the fixing device 100 of the present embodiment as described above, the following operational effects can be obtained.
First, when the fixing device 100 is assembled, the right end portion of the first heater 120 and the right end portion of the second heater 130 are connected by the insulator 199, and the terminal plate corresponding to each lead pin of the heater is fixed. Next, the heaters 120 and 130 to which the first terminal plate 170 is fixed are passed through the heating unit 110. Next, after passing the connecting portion 172 through the rectangular hole 163A, the first terminal board 170 is brought into contact with the support surface 163. Next, after the shielding member 270 is engaged with the notch portion 162 </ b> A of the wall portion 162, the regulating member 200 is disposed on the fixing frame 160.
After the fixing device 100 is assembled, the rear cover 2B is opened, and the fixing device 100 is mounted on the mounting portion 2A from the rear side of the main body frame 2. Then, a connector (not shown) is connected to the connection portion 172 of the terminal member 170.

  In the fixing device 100 assembled in this way, when the heaters 120 and 130 to which the first terminal plate 170 is fixed are passed through the heating unit 110, the smallest circle 177 including the first terminal plate 170 is seen from the first direction. Since it is smaller than the opening 110 </ b> A of the heating unit 110, the heaters 120 and 130 to which the first terminal plate 170 is fixed can be inserted into the heating unit 110 and assembled.

  Further, since the smallest circle 177 including the first terminal plate 170 is smaller than the opening hole 115 of the roller gear 112 when viewed from the first direction, the heaters 120 and 130 to which the first terminal plate 170 is fixed are placed in the heating unit 110. Can be inserted and assembled.

  Further, since the tip of the connecting portion 172 of the first terminal board 170 is smaller than the predetermined radial width H1 of the groove 117 of the roller gear 112, the first terminal board 170 is fixed by aligning the direction of the connecting portion 172 with the groove 117. The heaters 120 and 130 thus made can be easily passed through the opening hole 115 of the roller gear 112.

  As shown in FIG. 9A, in the fixing device 300 according to the conventional technique, the connection portion 311 that connects the connector C to the terminal plate 310 has an edge in a direction orthogonal to the longitudinal direction of the heater 320 in the terminal plate 310. It was extended from. For this reason, the connecting portion 311 and the connector C are arranged near the end portion in the first direction of the fixing device 300. For this reason, the fixing device 300 is a portion in which the connecting portion 311 is provided and has a size in the first direction. Was big.

  However, in the fixing device 100, the heating unit 110, the first glass tube 121 as an example of the heater main body extending in the first direction, the first lead pin 122 protruding from the end surface of the one glass tube 121, and the lead pin 122 are fixed. The first terminal board 170 and the fixing frame 160 for indicating the first terminal board 170 may be provided. The first terminal board 170 includes a plate-like main body 171 and a connection part 172 extending from the main body 171 in a direction intersecting the surface 171B. Further, the connecting portion 172 extends from the edge 171A of the main body portion 171 on the first glass tube 121 side. Accordingly, as shown in FIG. 9B, the connecting portion 172 and the connector C can be disposed closer to the center of the fixing device 100 than the fixing device 300 in the conventional technique. For this reason, the portion where the connection portion 311 is conventionally arranged can be reduced in size, and the size of the fixing device 100 in the first direction can be reduced.

  Accordingly, for example, the fixing device 100 can include a metal reinforcing frame 290 that extends in the first direction and is connected to the fixing frame 160. The fastening portion 290 </ b> A between the reinforcing frame 290 and the fixing frame 160 can be disposed outside the connecting portion 172 in the first direction.

  In addition, the fixing device 100 includes a first round hole 173 that is an example of an engaging portion in which the main body portion 171 of the first terminal board 170 engages with the fixing frame 160. Thereby, the first terminal board 170 can be positioned on the fixing frame 160.

  Further, the fixing device 100 can be configured so that the connecting portion 172 of the first terminal plate 170 is oblique to the perpendicular D2 of the main body portion 171 when viewed from the first direction. This increases the degree of freedom in designing the heater end.

  In addition, the fixing device 100 may be configured such that the fixing frame 160 includes the wall portion 162 and the shielding member 270 is disposed in the notch portion 162 </ b> A of the wall portion 162. Thereby, it can suppress that the member around the 1st terminal board 170 and the 1st terminal board 170 is heated by the radiant heat of a heater.

  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 addition, about the component similar to the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the said embodiment, although the connection part 172 of the 1st terminal board 170 extended diagonally with respect to the perpendicular D2 of the main-body part 171, this invention is not limited to this. Further, the main body 171 of the first terminal board 170 may not be rectangular.

For example, in the first terminal plate 470 in the embodiment shown in FIG. 10, the main body 471 has a rectangular first portion 471A and a first portion 471A extending from the first portion 471A to the second glass tube 131 side of the second heater 130. 2 portions 471B. The first lead pin 122 of the first heater 120 is fixed to the first portion 471A, and the second lead pin 132 of the second heater 130 is fixed to the second portion 471B. The connecting portion 472 extends from the edge 475 of the first portion 417A on the first glass tube 121 side in the main body portion 471. The direction in which the connecting portion 472 extends is parallel to the perpendicular of the main body portion 471.
Even in the configuration in which the first terminal plate 470 in the embodiment shown in FIG. 10 is arranged in the fixing device, the space at the end of the fixing device can be effectively used in the first direction (longitudinal direction of the heater), and the design freedom The degree can be improved.

  In the said embodiment, although the hollow roller was illustrated as a heating part which transmits the heat | fever of a heater to a sheet | seat, this invention is not limited to this. For example, the heating unit may be a belt.

  In the said embodiment, although the control member had the 1st control part and the 2nd control part, you may have only either one of two control parts.

  In the embodiment, the fixing device includes two heaters, but the number of heaters is not limited to this. For example, the number of heaters may be one, or three or more.

  In the embodiment, the halogen lamp is exemplified as the heater. However, the heater is not limited to this, and may be, for example, a carbon heater or a ceramic heater which is a resistance heating element.

  Moreover, each element of each above-mentioned embodiment and each modification can be implemented in arbitrary combinations.

3 Sheet 100 Fixing Device 110 Heating Unit 120 First Heater 121 First Glass Tube 122 First Lead Pin 130 Second Heater 131 Second Glass Tube 132 Second Lead Pin 160 Fixing Frame 170 First Terminal Board 171 Body 171A Edge 172 Connection Portion

Claims (8)

A heating unit for heating the sheet;
A heater for heating the heating unit, the heater having a heater main body extending in a first direction, and a lead pin protruding from an end surface of the heater main body in the first direction;
A terminal plate to which the lead pins are fixed;
A frame for supporting the terminal plate,
The terminal plate has a plate-like main body portion supported by the frame, and a connection portion extending from the main body portion in a direction intersecting the main body portion,
The fixing device, wherein the connection portion extends from an edge of the main body portion on the heater main body side. The main body has an engaging portion that engages with the frame;
The fixing device according to claim 1, wherein the engaging portion is located farther from the heater main body than the connection portion.   3. The fixing device according to claim 1, wherein a direction in which the connection portion extends is oblique with respect to a perpendicular of the main body portion when viewed from the first direction. The heater includes a first heater having a first lead pin and a second heater having a second lead pin,
4. The fixing device according to claim 1, wherein the first lead pin and the second lead pin are fixed to the terminal plate. 5. The heating unit is a hollow roller having an opening at an end,
The heater is disposed inside the heating unit,
5. The fixing device according to claim 1, wherein a minimum circle including the terminal plate is smaller than the opening when viewed from the first direction. The roller has a gear having an opening hole,
The fixing device according to claim 5, wherein a minimum circle including the terminal plate is smaller than the opening hole when viewed from the first direction. The roller has a gear having an opening hole,
The opening hole has a circular hole along a circular shape, and a groove portion recessed in a radial direction from the circular hole with a predetermined width,
7. The fixing device according to claim 5, wherein a dimension of the connection portion in a direction orthogonal to a direction in which the connection portion extends is smaller than the predetermined width when viewed from the first direction. 8. . The frame has a wall portion located between the heater main body and the terminal plate,
The wall has a notch through which the lead pin passes,
8. The shielding member for suppressing radiant heat of the heater from leaking from the heater main body side of the wall portion to the terminal plate side is disposed in the notch portion. The fixing device according to any one of the above

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