Fixing device

Abstract

To increase the rigidity of a fixing device 1 and prevent a relay substrate 12 from being affected by heat of a heating member 2.SOLUTION: A fixing device 1 comprises a heating member 2, a pressure member 3, a pair of side frames 4, a metal connection frame 4C, a fixing connector, a first temperature sensor, a second temperature sensor, a relay substrate 12, a first cable, a second cable, and a third cable. The heating member 2 extends in a longitudinal direction and has a heater H. The pair of side frames 4 is located at both ends on one side and the other side in a longitudinal direction of the heating member 2 and the pressure member 3, and rotatably supports the heating member 2 or the pressure member 3. The connection frame 4C extends in the longitudinal direction, and connects the pair of side frames 4 to each other. The relay substrate 12 is located on the opposite side of the heating member 2 with the connection frame 4C therebetween, and a resin first frame 20 is provided between the relay substrate 12 and the connection frame 4C.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a fixing device that can be attached to the main body of an image forming apparatus. [Background technology]

[0002] A fixing device that can be attached to the main body of an image forming apparatus is known (see Patent Document 1). This fixing device has a heating element with a heat source, a connector on the fixing element side that transmits signals to the image forming apparatus, and multiple sensors. Signals from the multiple sensors are relayed to the connector on the fixing element side by a relay board. The relay board is provided adjacent to and in front of the heating element, and is held by a holding member fixed to a resin exterior member that connects the left and right side frames. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-113967 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to increase the rigidity of the fixing device, it is desirable to connect the left and right side frames of the fixing device with a metal frame. However, if the relay board is placed on a metal frame, it may be affected by the heat of the heating member.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to increase the rigidity of the fixing device and to make the relay board less susceptible to the heat of the heating member. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the fixing device includes a heating member, a pressure member, a pair of side frames, a metal connection frame, a fixing connector, a first temperature sensor, a second temperature sensor, a relay board, a first cable, a second cable, and a third cable, and is mountable to the main body of the image forming apparatus. The heating element extends longitudinally and includes a heater. The pressure member extends longitudinally and nip the sheet between the pressure member and the heating member. The pair of side frames are positioned at both ends of the heating member and the pressure member in the longitudinal direction, and rotatably support the heating member or the pressure member. The metal connecting frame extends in the longitudinal direction and connects the pair of side frames. The fixing connector is connectable to the main body housing. The first temperature sensor detects the temperature of the heating member. The second temperature sensor detects the temperature of the heating element. The relay board relays the signal from the first temperature sensor to the fixing connector, and also relays the signal from the second temperature sensor to the fixing connector. The first cable connects the first temperature sensor and the relay board. The second cable connects the second temperature sensor to the relay board. The third cable connects the relay board and the fixed connector. The relay board is located on the opposite side of the connection frame from the heating member, and a first frame made of resin is provided between the relay board and the connection frame.

[0007] Connecting the pair of side frames with a metal connecting frame increases the rigidity of the fixing device. Also, even if the relay board is located on the opposite side of the connecting frame from the heating element, the placement of the first resin frame between the relay board and the connecting frame makes it less susceptible to the heat from the heating element.

[0008] The relay substrate may be located above the heating element.

[0009] By positioning the relay board above the heating member, the dimensions of the fixing device in the front-to-rear direction can be made smaller than when the relay board is positioned in front of or behind the heating member.

[0010] The first temperature sensor may be located above the heating element.

[0011] The first temperature sensor and the second temperature sensor may be held by the connecting frame.

[0012] The first frame may have a base wall facing the relay board, and a support wall extending from the base wall toward the relay board and supporting the relay board with a gap formed between the relay board and the base wall.

[0013] By supporting the relay board with the support wall forming a gap between the relay board and the base wall, the heat of the heating member can be insulated from the relay board by the air layer.

[0014] The first frame may hold a third cable.

[0015] The first frame holds the third cable, thereby protecting the third cable from contact with the connection frame.

[0016] A second frame made of resin may be provided between the first frame and the connection frame.

[0017] By providing the second frame made of resin between the first frame and the connection frame, the heat from the heating member can be doubly insulated from the relay board.

[0018] The fixing connector is located on the other longitudinal side of the longitudinal center of the heating member, and the fixing device further includes a first power cable connecting the fixing connector to one longitudinal side of the heater, and the first power cable may extend between the first frame and the second frame.

[0019] By having the first power cable extend between the first frame and the second frame, the first power cable can be protected from contact with the connection frame.

[0020] The fixing connector may be located on the outside of the other side frame in the longitudinal direction.

[0021] The fixing connector is positioned outside the other side frame in the longitudinal direction, so that interference between the fixing connector and the sheet can be suppressed.

[0022] The fixing device further includes a connector holder that holds the fixing connector, and the connector holder may extend longitudinally from one side of the other side frame to the other side, and may have a harness holder that holds a third cable, and may have a harness holder that extends between an edge that faces a direction perpendicular to the longitudinal direction of the other side frame and the third cable.

[0023] The harness holder extends between the edge of the side frame that faces in a direction perpendicular to the longitudinal direction and the third cable, thereby preventing the third cable from coming into contact with the side frame.

[0024] The fixing device may further include a cover that covers the relay board.

[0025] The fixing device is provided with a cover, so that the relay board can be protected.

[0026] The cover may have a vent above the relay board.

[0027] The cover has a vent hole above the relay board, so that air inside the fixing device can be discharged through the vent hole.

[0028] The fixing device may further include a sheet sensor that detects a sheet that has passed between the heating member and the pressure member, and a fourth cable that connects the sheet sensor to the relay board.

[0029] By providing the fixing device with the fourth cable that connects the sheet sensor and the relay board, it is possible to simplify the wiring from the sheet sensor to the fixing connector.

[0030] The fixing device may further include a pressure change mechanism that changes the nip pressure between the heating member and the pressure member, the pressure change mechanism having a cam, a cam sensor that detects the phase of the cam, and a fifth cable that connects the cam sensor to the relay board.

[0031] By providing the fixing device with the fifth cable that connects the cam sensor and the relay board, it is possible to simplify the wiring from the cam sensor to the fixing connector. [Effects of the Invention]

[0032] According to the present invention, the rigidity of the fixing device can be increased, and the relay board can be made less susceptible to the heat of the heating member. [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 2 is a cross-sectional view of the fixing device, showing a state when the cam is in a first phase. [Figure 2] FIG. 4 is a cross-sectional view of the fixing device, showing a state when the cam is in a second phase. [Figure 3] FIG. 2 is a perspective view showing a fixing frame. [Figure 4] FIG. 2 is a perspective view showing the arrangement of a relay board, a sensor, a cable, and a fixing connector relative to a fixing frame. [Figure 5] 5 is a perspective view of the fixing frame of FIG. 4 as seen from the mounting direction of the fixing device. [Figure 6] FIG. 10 is a diagram showing wiring between a heater, a sensor, a relay board, and a fixing connector. [Figure 7]5 is a perspective view showing a rear guide disposed on the fixing frame of FIG. 4 and an intermediate board indicated by an imaginary line. [Figure 8] 8 is a perspective view showing a state in which a first harness holder is disposed on the rear guide of FIG. 7. FIG. [Figure 9] 9 is a partial enlarged view of the other side in the longitudinal direction of FIG. 8. FIG. [Figure 10] 9 is a cross-sectional view taken along the line AA in FIG. 8. [Figure 11] FIG. 2 is a view of one end of the fixing device in the longitudinal direction as viewed from below. [Figure 12] FIG. 9 is a perspective view of the relay board of FIG. 8 with a cover placed thereon. [Figure 13] FIG. 8 is a plan view corresponding to FIG. 7. [Figure 14] 3 is a schematic diagram showing gear meshing and connector connection when the fixing device is mounted in the main body housing of the image forming apparatus. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0034] Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, the fixing device 1 is a device that fixes a toner image on a sheet S. The fixing device 1 can be attached to a main body housing M (see FIG. 13) of an image forming apparatus P such as a printer. The fixing device 1 includes a heating roller 2 as an example of a heating member, a pressure roller 3 as an example of a pressure member, a fixing frame 4, an arm 5, a spring 6, and a cam 7.

[0035] The heating roller 2 extends in the longitudinal direction and rotates around a rotation axis X. The heating roller 2 rotates by receiving a driving force from a motor (not shown) provided in the image forming apparatus P. The heating roller 2 has a roller 2A and a heater H. In this embodiment, the heating roller 2 has two heaters H1 and H2. The roller 2A is a metal tube and is heated by the heater H. The heater H is disposed inside the roller 2A. The heater H is, for example, a halogen heater.

[0036] In the following description, the longitudinal direction of the heating roller 2 will be simply referred to as the longitudinal direction. The longitudinal direction is also the direction of the rotation axis X of the heating roller 2. The direction in which the fixing device 1 is attached to the main body housing M will be referred to as the attachment direction, and the direction in which the fixing device 1 is removed from the main body housing M will be referred to as the removal direction. The attachment direction and removal direction correspond to the front and rear of the main body housing M, respectively. The attachment direction and removal direction will collectively be referred to as the attachment / removal direction. The front-to-rear and up-to-down directions of the fixing device 1 are the front-to-rear and up-to-down directions of the main body housing M when the fixing device 1 is attached to the main body housing M. The sheet S is transported from the front to the rear of the fixing device 1 and passes through the fixing device 1. After passing through the fixing device 1, the sheet S is transported upward above the fixing device 1.

[0037] The pressure roller 3 extends in the longitudinal direction. The pressure roller 3 rotates following the rotation of the heat roller 2, and nips the sheet S between the heat roller 2. The pressure roller 3 has a shaft 3A and a roller body 3B. The shaft 3A is made of, for example, metal. The roller body 3B is made of, for example, rubber, and is provided so as to cover the periphery of the shaft 3A.

[0038] 3, the fixing frame 4 includes a pair of side frames 4A and 4B and a connecting frame 4C. The side frames 4A and 4B are located at both ends in the longitudinal direction of the heating roller 2 and the pressure roller 3. The side frames 4A and 4B support the heating roller 2 rotatably. The connecting frame 4C is a metal plate that extends in the longitudinal direction and connects the side frame 4A on one side in the longitudinal direction to the side frame 4B on the other side in the longitudinal direction.

[0039] The cam 7 includes a cam 7A and a cam 7B. The cam 7A is located close to the side frame 4A. The cam 7B is located close to the side frame 4B. The cams 7A and 7B are connected by a camshaft 8. The camshaft 8 is rotatably supported by the side frames 4A and 4B.

[0040] Returning to FIG. 1 , the arm 5, spring 6, and cam 7 constitute a pressure change mechanism that changes the nip pressure between the heating roller 2 and the pressure roller 3. The pressure change mechanism can change the nip pressure by moving at least one of the heating roller 2 and the pressure roller 3 relative to the other. In this embodiment, the pressure change mechanism changes the nip pressure by moving the pressure roller 3 relative to the heating roller 2.

[0041] The arm 5 has one end 5A, another end 5B, a first portion 5C, and a second portion 5D. The arm 5 is rotatable about an arm axis 1X.

[0042] One end 5A is rotatably supported by a side frame 4A on one side in the longitudinal direction via a shaft 5E. The other end 5B has a cam follower 5F. The cam follower 5F is capable of coming into contact with the cam 7.

[0043] The first portion 5C and the second portion 5D are located between the one end 5A and the other end 5B. The first portion 5C supports the pressure roller 3. The second portion 5D is a portion to which a spring 6 is connected. One end of the spring 6 is hooked to the second portion 5D, and the other end of the spring 6 is hooked to the side frame 4A. The spring 6 presses the pressure roller 3 against the heating roller 2 via the arm 5.

[0044] The cam 7A is rotatably supported by the side frame 4A on one side in the longitudinal direction via a camshaft 8, and is rotatable around the camshaft 2X. The cam 7A moves the pressure roller 3 by rotating, thereby changing the nip pressure that nips the sheet S. The cam 7A is rotatable between a first phase shown in FIG. 1 and a second phase shown in FIG. 2.

[0045] The first phase is a phase where the nip pressure becomes a first nip pressure. The second phase is a phase where the nip pressure becomes a second nip pressure that is lower than the first nip pressure. Cam 7A can rotate counterclockwise from the first phase shown in FIG. 1 to the second phase shown in FIG. 2.

[0046] The arm 5, spring 6 and cam 7B provided on the side frame 4B on the other side in the longitudinal direction have a configuration symmetrical to the arm 5, spring 6 and cam 7A provided on the side frame 4A on one side in the longitudinal direction, so detailed explanation will be omitted.

[0047] 3, the fixing device 1 further includes a cam gear 9 and a fixing gear 10. The cam gear 9 is fixed to one end of the camshaft 8 in the longitudinal direction. The cam gear 9 is connected to the cam 7 via the camshaft 8 and transmits driving force to the cam 7. The cam gear 9 has a plurality of gear teeth 9A and a flange 9B extending from near the base of the gear teeth 9A to one side in the longitudinal direction. The flange 9B has a notch 9C for detecting the phase of the cam 7.

[0048] The fixing gear 10 has a plurality of gear teeth 10A. The fixing gear 10 is fixed to one longitudinal end of the roller 2A. The fixing gear 10 is provided coaxially with the heating roller 2 and rotates integrally with the heating roller 2 about the rotation axis X. The fixing gear 10 transmits driving force to the heating roller 2.

[0049] As shown in FIGS. 4 and 5, the fixing device 1 further includes a first temperature sensor S1, a second temperature sensor S2, a sheet sensor S3, a cam sensor S4, a fixing connector 11, and a relay board 12.

[0050] The first temperature sensor S1 is a sensor that detects the temperature of the heating roller 2. The first temperature sensor S1 is located away from the heating roller 2. The first temperature sensor S1 is held to the connecting frame 4C by screws or the like. The first temperature sensor S1 is located above the heating roller 2. The first temperature sensor S1 is, for example, a thermistor.

[0051] The second temperature sensor S2 is a sensor that detects the temperature of the heating roller 2. The second temperature sensor S2 is in contact with the heating roller 2. The second temperature sensor S2 is held to the connecting frame 4C by screws or the like. The second temperature sensor S2 is, for example, a thermistor.

[0052] The sheet sensor S3 is a sensor that detects the sheet S that has passed between the heating roller 2 and the pressure roller 3. The sheet sensor S3 has a rotating member 14 that rotates when it comes into contact with the sheet S, and an optical sensor 15.

[0053] The optical sensor 15 has a light emitting portion that emits light and a light receiving portion that receives the light from the light emitting portion. The optical sensor 15 emits light from the light emitting portion along the longitudinal direction.

[0054] The rotating member 14 has a first lever 14A that can come into contact with the sheet S, a second lever 14B that can block the light of the optical sensor 15, and a shaft 14C that connects the first lever 14A and the second lever 14B. The rotating member 14 is rotatable about the shaft 14C.

[0055] When the rotating member 14 is not in contact with the sheet S as shown in FIGS. 4 and 5, the second lever 14B blocks the light from the optical sensor 15. The rotating member 14 rotates when the first lever 14A is pressed by the sheet S. This causes the second lever 15B to move out of the light from the optical sensor 15. Therefore, when the light receiving portion of the optical sensor 15 does not receive light, it can be determined that the sheet S has not passed, and when the light receiving portion of the optical sensor 15 receives light, it can be determined that the sheet S has passed.

[0056] The cam sensor S4 is a sensor that detects the phase of the cam 7. The cam sensor S4 has an optical sensor 16.

[0057] The optical sensor 16 has a light emitting portion that emits light and a light receiving portion that receives the light from the light emitting portion. The optical sensor 16 emits light from the light emitting portion in the vertical direction.

[0058] 4, when the cam 7 is in the first phase, the light from the optical sensor 16 is blocked by the flange 9B of the cam gear 9. When the cam 7 rotates to the second phase, the light receiving portion of the optical sensor 15 can receive light through the notch 9C provided in the flange 9B of the cam gear 9. Therefore, when the light receiving portion of the optical sensor 15 receives light, it is possible to determine that the cam 7 is in the second phase, and when the light receiving portion of the optical sensor 15 does not receive light, it is possible to determine that the cam 7 is in a phase other than the second phase.

[0059] The fixing connector 11 can be connected to the main body housing M when the fixing device 1 is attached to the main body housing M. More specifically, the fixing connector 11 can be connected to a main body connector 18 (see FIG. 13) provided on the main body housing M when the fixing device 1 is attached to the main body housing M. The fixing connector 11 is located outside the pair of side frames 4A, 4B in the longitudinal direction. More specifically, the fixing connector 11 is located outside the side frame 4B on the other side in the longitudinal direction.

[0060] The relay board 12 relays signals from the first temperature sensor S1, the second temperature sensor S2, the sheet sensor S3, and the cam sensor S4 to the fixing connector 11. The relay board 12 has a second temperature sensor connector CN1, a sheet sensor connector CN2, a cam sensor connector CN3, a first temperature sensor connector CN4, and a relay connector CN5.

[0061] 6, the relay board 12 is connected to the first temperature sensor S1 by a first cable C1. The relay board 12 is connected to the second temperature sensor S2 by a second cable C2. The relay board 12 is also connected to the fixing connector 11 by a third cable C3. The relay board 12 is further connected to the sheet sensor S3 by a fourth cable C4 and to the cam sensor S4 by a fifth cable C5.

[0062] The heaters H1 and H2 of the heating roller 2 are connected to the fixing connector 11 on one side in the longitudinal direction by a first power cable PC1. More specifically, the heaters H1 and H2 are connected to the fixing connector 11 by the first power cable PC1 via a thermostat TM. The heaters H1 and H2 are connected to the fixing connector 11 on the other side in the longitudinal direction by second power cables PC2 and PC2. The thermostat TM cuts off the power when the temperature of the heating roller 2 exceeds the control range and becomes overheated.

[0063] 6, the fixing device 1 is attached to the main body housing M. When the fixing device 1 is attached to the main body housing M, the fixing connector 11 is connected to the main body connector . When the fixing connector 11 and the main body connector 18 are connected, it becomes possible to send temperature information detected by the temperature sensors S1 and S2, sheet information detected by the sheet sensor S3, and the phase of the cam 7 detected by the cam sensor S4 to the control unit MC of the image forming apparatus P. Furthermore, when the fixing connector 11 and the main body connector 18 are connected, it becomes possible to supply power to the heater H from the heater drive unit HC of the main body housing M. The heater drive unit HC is controlled by the control unit MC, and supplies power to the heater H based on the temperature information detected by the temperature sensors S1 and S2.

[0064] As shown in FIGS. 7 to 9, the fixing device 1 further includes a first harness holder 20 as a first frame and a rear guide 30 as a second frame.

[0065] 7, the rear guide 30 is a member that guides the sheet S discharged from between the heating roller 2 and the pressure roller 3. The rear guide 30 is made of resin. The rear guide 30 has a guide main body 31 and a guide portion 32 that extends upward from the guide main body 31.

[0066] The guide body 31 extends in the longitudinal direction and the installation direction so as to cover the connection frame 4C. The guide body 31 guides the first power cable PC1 from one longitudinal side of the heater H to the fixed connector 11. The guide body 31 has a first holding portion 33, a second holding portion 34, a third holding portion 35, a fourth holding portion 36, a fifth holding portion 37, a sixth holding portion 38, and a first guide wall 39.

[0067] The first holding portion 33 and the second holding portion 34 hold the first power cable PC1. A plurality of first holding portions 33 are provided. Specifically, two first holding portions 33 are provided on one longitudinal side of the longitudinal center CL1 of the heating roller 2, and one first holding portion 33 is provided on the other longitudinal side of the longitudinal center CL1 of the heating roller 2. The first holding portions 33 are a pair of protrusions aligned in the installation direction and protrude upward from the guide body 31. The first holding portion 33 holds the first power cable PC1 between the pair of protrusions. The first holding portion 33 restricts movement of the first power cable PC1 in the installation / detachment direction.

[0068] The second holding portion 34 is provided between the first holding portion 33 and the fixing connector 11 on the other longitudinal side of the longitudinal center CL1 of the heating roller 2. The second holding portion 34 is an L-shaped portion that protrudes upward from the guide main body 31. The second holding portion 34 has an extending portion 34A that extends upward from the guide main body 31 and a hook portion 34B that extends from the upper end of the extending portion 34A in the removal direction. The second holding portion 34 restricts upward movement of the first power cable PC1 and in the installation direction.

[0069] The third holding portion 35, the fourth holding portion 36, and the fifth holding portion 37 hold the fourth cable C4 and the fifth cable C5. The third holding portion 35 is located at the front end on one longitudinal side of the guide main body 31. The third holding portion 35 is a pair of protrusions that protrude from the guide main body 31 in the installation direction. The third holding portion 35 holds the fourth cable C4 and the fifth cable C5 between the pair of protrusions. The third holding portion 35 restricts longitudinal movement of the fourth cable C4 and the fifth cable C5.

[0070] The fourth holding portion 36 is located above the third holding portion 35 and on the other side in the longitudinal direction. The fourth holding portion 36 is an L-shaped portion that protrudes upward from the guide main body 31. The fourth holding portion 36 has an extending portion 36A that extends upward from the guide main body 31 and a hook portion 36B that extends in the installation direction from the upper end of the extending portion 36A. The fourth holding portion 36 restricts upward movement of the fourth cable C4 and the fifth cable C5.

[0071] The fifth holding portion 37 is located on the other longitudinal side of the fourth holding portion 36. The fifth holding portion 37 is an L-shaped portion that protrudes from the guide main body 31 in the attachment direction. The fifth holding portion 37 has an extending portion 37A that extends from the guide main body 31 in the attachment direction, and a hook portion 37B that extends downward from the front end of the extending portion 37A. The fifth holding portion 37 restricts the upward movement of the fourth cable C4 and the fifth cable C5 and the attachment / detachment direction.

[0072] The sixth holding portion 38 holds the first cable C1 and the third cable C3. The sixth holding portion 38 is located on the other longitudinal side of the fifth holding portion 37. The sixth holding portion 38 is an L-shaped portion that protrudes from the guide main body 31 in the attachment direction. The sixth holding portion 38 has an extending portion 38A that extends from the guide main body 31 in the attachment direction, and a hook portion 38B that extends downward from the front end of the extending portion 38A. The sixth holding portion 38 restricts the upward movement of the first cable C1 and the second cable C2 and the attachment / detachment direction.

[0073] The first guide wall 39 guides the fourth cable C4 and the fifth cable C5 between the fourth holding portion 36 and the fifth holding portion 37 in the longitudinal direction.

[0074] 8, the first harness holder 20 is a member that supports the relay board 12. The first harness holder 20 is made of resin. The first harness holder 20 has a base wall 21, a claw 21A, a support wall 22, a seventh holding portion 23, an eighth holding portion 24, a ninth holding portion 25, a tenth holding portion 26, an eleventh holding portion 27, a second guide wall 28, and a third guide wall 29.

[0075] The base wall 21 extends in the longitudinal direction and the mounting direction so as to cover a portion of the guide body 31 of the rear guide 30. The base wall 21 faces the relay board 12. The claws 21A extend upward from the base wall 21 toward the relay board 12.

[0076] The support wall 22 extends upward from the base wall 21 toward the relay board 12. The relay board 12 is supported on the upper end of the support wall 22 (see also FIG. 10). One longitudinal end of the relay board 12 is fixed to the first harness holder 20 by a screw or the like, and the other longitudinal end of the relay board 12 is held to the first harness holder 20 by a claw 21A.

[0077] The seventh holding portion 23 and the eighth holding portion 24 hold the second cable C2. The seventh holding portion 23 is located at the rear end on one longitudinal side of the base wall 21. The seventh holding portion 23 is an L-shaped portion extending upward from the base wall 21. The seventh holding portion 23 has an extending portion 23A extending upward from the base wall 21 and a hook portion 23B extending from the upper end of the extending portion 23A in the removal direction. The seventh holding portion 23 restricts upward movement of the second cable C2 and in the attachment direction.

[0078] The eighth holding portion 24 is located on the other longitudinal side and in front of the seventh holding portion 23. The eighth holding portion 24 is a pair of protrusions that protrude upward from the base wall 21. The eighth holding portion 24 holds the second cable C2 between the pair of protrusions. The eighth holding portion 24 restricts movement of the second cable C2 in the attachment / detachment direction.

[0079] The ninth holding portion 25, the tenth holding portion 26, and the eleventh holding portion 27 hold the third cable C3. The ninth holding portion 25 is located on the other longitudinal side of the eighth holding portion 24. As shown in Fig. 9, the ninth holding portion 25 has an extending portion 25A extending upward from the base wall 21 and a hook portion 25B extending in the removal direction from the upper end of the extending portion 25A. The ninth holding portion 25 restricts upward movement of the third cable C3 and the attachment direction.

[0080] The tenth holding portion 26 is located on the other longitudinal side of the ninth holding portion 25. The tenth holding portion 26 has a first extending portion 26A extending upward from the base wall 21, a second extending portion 26B extending in the attachment direction from the first extending portion 26A, and a hook portion 26C extending downward from the front end of the second extending portion 26B. The tenth holding portion 26 restricts upward movement of the third cable C3 and in the attachment / detachment direction.

[0081] The eleventh holding portion 27 is located on the other longitudinal side of the tenth holding portion 26. The eleventh holding portion 27 has an extending portion 27A extending upward from the base wall 21 and a hook portion 27B extending in the removal direction from the extending portion 27A. The eleventh holding portion 27 restricts upward movement of the third cable C3 and the attachment direction.

[0082] The second guide wall 28 is located between the ninth holding portion 25 and the tenth holding portion 26, and guides the third cable C3 in the longitudinal direction. The third guide wall 29 is located between the tenth holding portion 26 and the eleventh holding portion 27 and behind the second guide wall 28. The third guide wall 29 guides the third cable C3 in the longitudinal direction.

[0083] The fixing device 1 further includes a connector holder 40. The connector holder 40 is a member that holds the fixing connector 11. The connector holder 40 has a base portion 41, a first guide hole 42, a second guide hole 43, and a second harness holder 50. The base portion 41 is provided around the fixing connector 11 and holds the fixing connector 11. The first guide hole 42 and the second guide hole 43 engage with guide pins (not shown) of the main body connector 18 when the fixing device 1 is attached to the main body housing M.

[0084] The second harness holder 50 extends from one side to the other side of the other side frame 4B in the longitudinal direction. The second harness holder 50 extends between the edge 4E facing in a direction perpendicular to the longitudinal direction of the other side frame 4B (upward in this embodiment) and the third cable C3 and the first power cable PC1. The second harness holder 50 has a holder main body 51, a twelfth holding portion 52, and a thirteenth holding portion 53.

[0085] The twelfth holding portion 52 holds the first power cable PC1. The twelfth holding portion 52 is located on the other longitudinal side of the second holding portion 34 (see FIG. 7). The twelfth holding portion 52 extends from the holder main body 51 to one longitudinal side. The twelfth holding portion 52 has a groove 52A that guides the first power cable PC1. The twelfth holding portion 52 restricts movement of the first power cable PC1 in the attachment / detachment direction.

[0086] The thirteenth holding portion 53 holds the third cable C3. The thirteenth holding portion 53 is located on the other longitudinal side of the eleventh holding portion 27. The thirteenth holding portion 53 is an L-shaped portion that protrudes from the holder main body 51 in the attachment direction. The thirteenth holding portion 53 has an extending portion 53A that extends from the holder main body 51 in the attachment direction, and a hook portion 53B that extends downward from the front end of the extending portion 53A. The thirteenth holding portion 53 restricts upward movement of the third cable C3 and in the attachment / detachment direction.

[0087] As shown in FIG. 10 , the relay board 12 is located above the heating roller 2. The relay board 12 is located on the opposite side of the heating roller 2 across the connection frame 4C. The first harness holder 20 and the guide body 31 of the rear guide 30 are provided between the relay board 12 and the connection frame 4C, in this order from above. In other words, the guide body 31 of the rear guide 30 is provided between the first harness holder 20 and the connection frame 4C. The first power cable PC1 extends between the first harness holder 20 and the guide body 31 of the rear guide 30. The support wall 22 of the first harness holder 20 supports the relay board 12 with a gap SP formed between the relay board 12 and the base wall 21.

[0088] FIG. 11 is a view of one end of the fixing device 1 in the longitudinal direction as viewed from below. The fixing device 1 further includes a gear cover 60 that covers a portion of the plurality of gear teeth 10A of the fixing gear 10. The gear cover 60 covers the gear teeth 10A of the fixing gear 10 in the lower half. The gear cover 60 has a fourteenth holding portion 61, a fifteenth holding portion 62, and a sixteenth holding portion 63 (see FIG. 8).

[0089] The fourteenth holding portion 61 holds the fifth cable C5. The fourteenth holding portion 61 is located below the cam sensor S4. The fourteenth holding portion 61 is an L-shaped portion extending from the gear cover 60 in the removal direction. The fourteenth holding portion 61 has an extending portion 61A extending from the gear cover 60 in the removal direction, and a hook portion 61B extending from the rear end of the extending portion 61A to the other side in the longitudinal direction. The fourteenth holding portion 61 restricts movement of the fifth cable C5 in the attachment / detachment direction and the longitudinal direction.

[0090] The fifteenth holding portion 62 and the sixteenth holding portion 63 hold the fourth cable C4 and the fifth cable C5. The fifteenth holding portion 62 is located in front of the fourteenth holding portion 61. The fifteenth holding portion 62 is a plate-shaped portion that covers the fourth cable C4 and the fifth cable C5 from one side in the longitudinal direction. The fifteenth holding portion 62 restricts movement of the fourth cable C4 and the fifth cable C5 in the longitudinal direction.

[0091] As shown in FIG. 8 , the sixteenth holding portion 63 is located on one side of the fifteenth holding portion 62 in the longitudinal direction. The sixteenth holding portion 63 is an L-shaped portion that protrudes from the gear cover 60 to the other side in the longitudinal direction. The sixteenth holding portion 63 has an extending portion 63A that extends from the gear cover 60 to the other side in the longitudinal direction, and a hook portion 63B that extends downward from the front end of the extending portion 63A. The sixteenth holding portion 63 restricts upward movement of the fourth cable C4 and the fifth cable C5 and the attachment / detachment direction.

[0092] Next, an example of a procedure for attaching the first power cable PC1 to the fixing device 1 will be described with reference to FIGS.

[0093] The first power cable PC1 has a longitudinal portion connected to the heater H and a longitudinal portion connected to the fixed connector 11. When installing the first power cable PC1, the longitudinal portion of the first power cable PC1 is pulled upward from the heater H and routed longitudinally along the gear cover 60. Next, the longitudinal portion of the first power cable PC1 is passed between a pair of protrusions of each of the two first holding portions 33 located on one side of the longitudinal direction and connected to the thermostat TM. Next, the longitudinal portion of the first power cable PC1 is pulled rearward from the fixed connector 11, routed along the holder body 51 of the second harness holder 50, and placed in the groove 52A of the twelfth holding portion 52. The longitudinal portion of the first power cable PC1 is then hooked onto the second holding portion 34, passed between a pair of protrusions of the first holding portion 33 located on the other side of the longitudinal direction, and connected to the thermostat TM.

[0094] Next, an example of a procedure for attaching the cables C1 to C5 to the fixing device 1 will be described with reference to FIGS.

[0095] As shown in FIG. 8, when attaching the first cable C1, the first cable C1 is pulled upward from the first temperature sensor S1, passed under the sixth holding portion 38, and connected to the first temperature sensor connector CN4 of the relay board 12.

[0096] When attaching the second cable C2, the second cable C2 is pulled upward from the second temperature sensor S2 and hooked onto the seventh holding part 23. Next, the second cable C2 is routed so as to pass between the pair of protrusions of the eighth holding part 24 and connected to the second temperature sensor connector CN1 of the relay board 12.

[0097] When attaching the third cable C3, the third cable C3 is pulled out from the fixed connector 11 to one side in the longitudinal direction and routed around the periphery of the holder body 51 of the second harness holder 50. Next, the third cable C3 is passed under the thirteenth holding portion 53 and the eleventh holding portion 27, then under the tenth holding portion 26 and the ninth holding portion 25, and routed along the rear surfaces of the third guide wall 29 and the second guide wall 28. Next, the third cable C3 is passed under the sixth holding portion 38 and connected to the relay connector CN5 of the relay board 12.

[0098] When attaching the fourth cable C4, as shown in Fig. 11, the fourth cable C4 is pulled upward from the sheet sensor S3, then routed along the outer periphery of the portion of the gear cover 60 that covers the fixing gear 10, and passed through the fifteenth holding portion 62 and the sixteenth holding portion 63 as shown in Fig. 8. Next, the fourth cable C4 is passed upward between the pair of protrusions of the third holding portion 35. Next, the fourth cable C4 is passed below the fourth holding portion 36 and the fifth holding portion 37, routed along the rear surface of the first guide wall 39, and connected to the sheet sensor connector CN2 of the relay board 12.

[0099] As shown in FIG. 11, the cam sensor S4 is located above the heat roller 2. When attaching the fifth cable C5, the fifth cable C5 is pulled downward from the cam sensor S4 and hooked onto the fourteenth holding portion 61. Next, the fifth cable C5 is routed along the outer periphery of the portion of the gear cover 60 that covers the fuser gear 10 so as to pass below the heat roller 2. Next, as shown in FIG. 8, the fifth cable C5 is routed through the fifteenth holding portion 62, the sixteenth holding portion 63, the third holding portion 35, the fourth holding portion 36, and the fifth holding portion 37 in the same manner as the fourth cable C4, and is connected to the cam sensor connector CN3 of the relay board 12.

[0100] 12, the fixing device 1 further includes a cover 70 that covers the relay board 12. The cover 70 has a plurality of ventilation holes 71 above the relay board 12. The ventilation hole 71 allows the air inside the fixing device 1 to be discharged.

[0101] 13, the first temperature sensor S1 is located on one side of the longitudinal center CL1 of the heating roller 2, and detects the temperature of the heating roller 2 on one side of the longitudinal center CL1 of the heating roller 2. The first temperature sensor S1 (heat-sensitive portion of the first temperature sensor S1) is located between one end and the other end of the relay board 12 in the longitudinal direction. The first temperature sensor S1 also detects the temperature of the sheet S having the minimum width that can be fixed by the fixing device 1 in the longitudinal direction. min is located within the range through which the object passes, centered.

[0102] The second temperature sensor S2 is located on one side of the longitudinal center CL1 of the heat roller 2, and detects the temperature of the heat roller 2 on one side of the longitudinal center CL1 of the heat roller 2. The second temperature sensor S2 is located on one side of the longitudinal edge of the relay board 12. The second temperature sensor S2 also detects the temperature of the sheet S having the maximum width that can be fixed by the fixing device 1 in the longitudinal direction. max is located outside the range through which

[0103] The fixing connector 11 is located on the other side of the center CL1 of the heat roller 2 in the longitudinal direction. The sheet sensor S3 is located on one side of the center CL1 of the heat roller 2 in the longitudinal direction. The cam sensor S4 is located on one side of the center CL1 of the heating roller 2 in the longitudinal direction.

[0104] The longitudinal center CL2 of the relay board 12 is located on one longitudinal side of the longitudinal center CL1 of the heating roller 2. The other longitudinal edge of the relay board 12 is located on one longitudinal side of the longitudinal center CL1 of the heating roller 2. The one longitudinal edge of the relay board 12 is closer to the longitudinal center CL1 of the heating roller 2 than the one longitudinal end of the heating roller 2. The cam gear 9 is located on one side of the center CL1 of the heating roller 2 in the longitudinal direction.

[0105] 14, the fixing device 1 before being attached to the main body housing M is shown by a virtual line, and the fixing device 1 in a state where it is attached to the main body housing M is shown by a solid line. The main body housing M of the image forming apparatus P is further provided with a fixing drive gear 80 that rotates by receiving a driving force from a motor (not shown), and a cam drive gear 81. The fixing device 1 can be attached to the main body housing M with an openable cover 90 provided at the rear of the main body housing M. An image forming unit 100 that forms a toner image on a sheet S is provided inside the main body housing M. The image forming unit 100 supplies the sheet S on which the toner image has been formed to the fixing device 1.

[0106] When the fixing device 1 is attached to the main body housing M, the fixing gear 10 meshes with the fixing drive gear 80 and rotates by receiving a driving force from the fixing drive gear 80. When the fixing device 1 is attached to the main body housing M, the cam gear 9 meshes with the cam drive gear 81 and rotates by receiving a driving force from the cam drive gear 81.

[0107] As described above, the following effects can be obtained in this embodiment.

[0108] In this embodiment, the first temperature sensor S1, the second temperature sensor S2, the sheet sensor S3, and the cam sensor S4, which are located on one side of the heat roller 2 in the longitudinal direction, are connected to the relay board 12 by the first cable C1, the second cable C2, the fourth cable C4, and the fifth cable C5, respectively. The relay board 12 is also connected to the fixing connector 11, which is located on the other side of the heat roller 2 in the longitudinal direction, by the third cable C3.

[0109] Each of the cables C1 to C5 includes multiple signal lines. The number of signal lines included in the third cable C3 connecting the relay board 12 and the fixing connector 11 is smaller than the total number of signal lines included in the first cable C1, the second cable C2, the fourth cable C4, and the fifth cable C5 connecting the first temperature sensor S1, the second temperature sensor S2, the sheet sensor S3, and the cam sensor S4 to the relay board 12. This is because ground lines and the like can be shared. This simplifies the wiring connecting the first temperature sensor S1, the second temperature sensor S2, the sheet sensor S3, and the cam sensor S4 to the fixing connector 11 in the fixing device 1.

[0110] In addition, since the relay board 12 is located on one side of the heating roller 2 in the longitudinal direction, the first cable C1, second cable C2, fourth cable C4, and fifth cable C5 that connect the first temperature sensor S1, second temperature sensor S2, sheet sensor S3, and cam sensor S4 to the relay board 12 can be shortened.

[0111] By positioning relay board 12 above heat roller 2, the dimensions of fixing device 1 in the front-to-rear direction can be made smaller than when relay board 12 is positioned in front of or behind heat roller 2.

[0112] By positioning the fixing connector 11 on the outer side of the pair of side frames 4A, 4B in the longitudinal direction, interference between the fixing connector 11 and the sheet S can be suppressed.

[0113] By positioning the fixing gear 10 and the cam gear 9 on one side of the heat roller 2 in the longitudinal direction, i.e., on the opposite side of the fixing connector 11 in the longitudinal direction, it is possible to reduce the size of the fixing device 1. In addition, interference between the fixing gear 10 and the cam gear 9 and the fixing connector 11 can be suppressed.

[0114] The pair of side frames 4A, 4B of the fixing device 1 are connected by the metal connecting frame 4C, so that the rigidity of the fixing device 1 can be increased.

[0115] By providing the first harness holder 20 between the relay board 12 and the connection frame 4C, even when the relay board 12 is located on the opposite side of the connection frame 4C from the heating roller 2, the relay board 12 is less susceptible to the influence of the heat of the heating roller 2.

[0116] The first harness holder 20 has a base wall 21 and a support wall 22, and the support wall 22 supports the relay board 12 with a gap SP formed between the relay board 12 and the base wall 21, so that the air layer created by the gap SP can insulate the heat of the heating roller 2 from the relay board 12.

[0117] In addition, since the guide body 31 of the resin rear guide 30 is provided between the first harness holder 20 and the connecting frame 4C, the first harness holder 20 and the guide body 31 can provide doubly effective insulation of the heat from the heating roller 2 from the relay board 12.

[0118] The fifth cable C5, which connects the cam sensor S4 and the relay board 12, passes under the heating roller 2, making the fifth cable C5 less susceptible to the effects of heat from the heating roller 2. Furthermore, by holding the fifth cable C5 with the gear cover 60, contact between the fixing gear 10 and the fifth cable C5 can be suppressed.

[0119] The first harness holder 20 holds the third cable C3, thereby protecting the third cable C3 from contact with the connection frame 4C.

[0120] The first power cable PC1 extends between the first harness holder 20 and the guide body 31 of the rear guide 30, thereby protecting the first power cable PC1 from contacting the connection frame 4C.

[0121] The second harness holder 50 of the connector holder 40 extends between the edge of the side frame 4B facing in a direction perpendicular to the longitudinal direction and the third cable C3, thereby preventing the third cable C3 from coming into contact with the side frame 4B.

[0122] The fixing device 1 can be attached to the main body housing M of the image forming apparatus P. The fixing device 1 is provided with a cover 70 that covers the relay board 12, so that when the fixing device 1 is attached to the main body housing M or when the fixing device 1 is removed from the main body housing M, the relay board 12 can be protected from contact with other members or people inside the main body housing M.

[0123] In addition, since the cover 70 has an air vent 71 above the relay board 12, air heated by convection caused by a fan or the like installed inside the fixing device 1 can be discharged to the outside of the fixing device 1 through the air vent 71.

[0124] The present invention is not limited to the above-described embodiment, but can be used in various forms as exemplified below.

[0125] In the embodiment, the fixing device 1 can be attached to the main body housing M of the image forming apparatus P, but the fixing device 1 may also be fixed to the main body housing M so that it cannot be detached.

[0126] In the above embodiment, the heating roller 2 is used as the heating member, but the heating member may be, for example, a cylindrical fixing belt slidably supported by a guide.

[0127] In the above embodiment, the side frames 4A and 4B rotatably support the heating roller 2, but the side frames 4A and 4B may also rotatably support the pressure roller 3.

[0128] In the above embodiment, the heating roller 2 is driven and the pressure roller 3 rotates following the heating roller 2, but the pressure roller 3 may be driven and the heating roller 2 may rotate following the pressure roller 3. In this case, the fixing gear 10 is fixed to the pressure roller 3 and transmits the driving force to the pressure roller 3.

[0129] In the above embodiment, the pressure change mechanism changes the nip pressure by moving the pressure roller 3 relative to the heat roller 2, but the pressure change mechanism may change the nip pressure by moving the heat roller 2 relative to the pressure roller 3. Also, the fixing device 1 does not have to include a pressure change mechanism.

[0130] In the above embodiment, a halogen heater is used as the heater H, but the heater H may be a heating resistor or an IH heat source. Here, an IH heat source refers to a device that does not generate heat itself but heats a roller or a metal belt using electromagnetic induction heating. Also, in the above embodiment, the fixing device 1 includes two heaters H1 and H2, but the fixing device 1 may include one heater H or three or more heaters H.

[0131] The elements described in the above-described embodiment and modified examples may be implemented in any combination. [Explanation of symbols]

[0132] 1 Fixing device 2 Heating roller 3 Pressure roller 4A Side Frame 4B side frame 4C Connecting Frame 11 Fixing connector 12 Relay board 20 First harness holder C1 First cable C2 Second Cable C3 3rd cable CL1: longitudinal center of heating element CL2 Longitudinal center of relay board M Main unit housing P Image forming device H heater S1 First temperature sensor S2 Second temperature sensor

Claims

1. A fixing device that can be attached to a main body housing of an image forming apparatus, a heating element extending in a longitudinal direction and having a heater; a pressure member extending in the longitudinal direction and nipping the sheet between itself and the heating member; a pair of side frames positioned at both ends of the heating member and the pressure member in the longitudinal direction, the side frames rotatably supporting the heating member or the pressure member; a metal connection frame extending in the longitudinal direction and connecting the pair of side frames; a fixing connector connectable to the main body housing; a first temperature sensor that detects the temperature of the heating member; a second temperature sensor that detects the temperature of the heating member; a relay board that relays a signal from the first temperature sensor to the fixing connector and relays a signal from the second temperature sensor to the fixing connector; a first cable connecting the first temperature sensor and the relay board; a second cable connecting the second temperature sensor and the relay board; a third cable connecting the relay board and the fixed connector, The fixing device is characterized in that the relay board is located on the opposite side of the heating member across the connection frame, and a first frame made of resin is provided between the relay board and the connection frame.

2. 2. The fixing device according to claim 1, wherein the relay board is located above the heating member.

3. 3. The fixing device according to claim 2, wherein the first temperature sensor is located above the heating member.

4. 2. The fixing device according to claim 1, wherein the first temperature sensor and the second temperature sensor are held by the connection frame.

5. 2. The fixing device according to claim 1, wherein the first frame has a base wall facing the relay board, and a support wall extending from the base wall toward the relay board and supporting the relay board with a gap formed between the relay board and the base wall.

6. The fixing device according to claim 1 , wherein the first frame holds the third cable.

7. 2. The fixing device according to claim 1, further comprising a second frame made of resin provided between the first frame and the connecting frame.

8. a first power cable connecting the fixing connector and the one side of the heater in the longitudinal direction; the fixing connector is located on the other side in the longitudinal direction with respect to the center of the heating member in the longitudinal direction, 8. The fixing device according to claim 7, wherein the first power cable extends between the first frame and the second frame.

9. 2. The fixing device according to claim 1, wherein the fixing connector is located outside the other side frame in the longitudinal direction.

10. a connector holder for holding the fixing connector; The fixing device according to claim 9, characterized in that the connector holder is a harness holder that extends from one side of the other side frame to the other side in the longitudinal direction and holds the third cable, and has a harness holder that extends between an edge of the other side frame facing in a direction perpendicular to the longitudinal direction and the third cable.

11. The fixing device according to claim 1 , further comprising a cover for covering the relay board.

12. The fixing device according to claim 11 , wherein the cover has a vent hole above the relay board.

13. a sheet sensor that detects a sheet that has passed between the heating member and the pressure member; The fixing device according to claim 1 , further comprising a fourth cable connecting the sheet sensor and the relay board.

14. a pressure change mechanism for changing a nip pressure between the heating member and the pressure member, the pressure change mechanism having a cam; a cam sensor for detecting the phase of the cam; The fixing device according to claim 1 , further comprising: a fifth cable connecting the cam sensor and the relay board.

Images