Fixing device

Abstract

The present invention can effectively suppress the displacement of the connector relative to the heater in the long side direction and narrow the width of the heater in the short side direction. The fixing device (8) includes a flat heater (110), which has a metal substrate with a recess (113); a heating pattern (PH) composed of a resistive heating element arranged on the substrate; and a plurality of power supply terminals (T) that are connected to the heating pattern (PH) and are arranged at one end of the heater (110) in the long side direction. The fixing device (8) also includes a retaining member (120) that has a convex portion (125) that contacts the recess in the long side direction and supports the heater (110), and a connector (200) that has an electrode connected to the power supply terminal (T) and a snap-fitting portion that snaps into the retaining member (120) in the long side direction. The recess (113) is arranged in the long side direction between the heating pattern (PH) and a power supply terminal (T2) that is closest to the heating pattern (PH) among the plurality of power supply terminals (T).

Description

Technical Field

[0001] The present invention relates to a fixing device including a flat plate-shaped heater. Background Art

[0002] Conventionally, as a fixing device, there is known a device including a flat heater, a connector and a connector locking portion mounted on an end portion of the heater in the long-side direction (see Patent Document 1). Specifically, the connector and the connector locking portion are mounted on the heater in such a manner as to sandwich the end portion of the heater in the short-side direction. Furthermore, the connector locking portion is engaged with a recess formed at one end of the heater in the short-side direction, thereby limiting the displacement of the connector relative to the heater in the long-side direction.

[0003] The heater comprises a metal substrate, an insulating layer arranged on one surface of the substrate, a power supply terminal arranged on the insulating layer, and a heating pattern connected to the power supply terminal, wherein the substrate is exposed at an end surface of the heater, and the recess of the heater is arranged in the same range as the power supply terminal in the long side direction of the heater.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-191734

[0007] However, in a heater having a metal substrate, if the distance between the power supply terminal and the end surface of the substrate is close, discharge may occur between the power supply terminal and the end surface of the substrate through the air. Therefore, it is necessary to ensure a sufficient insulation distance between the power supply terminal and the end surface of the substrate. If the recess of the heater is set in the same range as the power supply terminal in the long side direction of the heater as in Patent Document 1, the distance between the end surface of the substrate exposed in the recess and the power supply terminal becomes closer. Therefore, in order to ensure a sufficient insulation distance, the width of the heater in the short side direction can only be expanded. If the width of the heater in the short side direction is wide, not only the material cost becomes high, but also the electrothermal efficiency is reduced. Summary of the invention

[0008] Therefore, an object of the present invention is to satisfactorily suppress displacement of a connector relative to a heater in the longitudinal direction and to narrow the width of the heater in the transverse direction.

[0009] In order to solve the above problem, the fixing device of the present invention is provided with a heater, a holder and a connector, wherein the heater is a flat plate-shaped heater and has: a metal substrate having a recessed portion; a heating pattern, which is composed of a resistive heating element arranged on the substrate; and a plurality of power supply terminals, which are connected to the heating pattern and are arranged at one end of the long side direction of the heater, wherein the holder has a convex portion in contact with the recessed portion in the long side direction and supports the heater, and the connector has an electrode connected to the power supply terminal and an engaging portion engaged with the holder in the long side direction. Moreover, the recessed portion is arranged in the long side direction between the heating pattern and the power supply terminal closest to the heating pattern among the plurality of power supply terminals.

[0010] According to such a structure, the displacement of the connector relative to the heater in the longitudinal direction can be well suppressed, and the width of the heater in the transverse direction can be narrowed while ensuring a sufficient insulation distance by staggering the recess and the power supply terminal in the longitudinal direction.

[0011] The recessed portion may be provided between the connector and the heat generating pattern in the longitudinal direction.

[0012] This allows the recess to be further away from the power supply terminal, and thus the insulation distance can be further ensured.

[0013] Alternatively, a distance between the recess and a power supply terminal closest to the heat generating pattern among the plurality of power supply terminals may be smaller than a distance between the recess and the heat generating pattern.

[0014] Thus, the convex portion of the holder in contact with the concave portion and the portion of the holder in contact with the engagement portion of the connector are arranged close to each other, so that displacement of the connector relative to the heater in the longitudinal direction can be more effectively suppressed.

[0015] Alternatively, the heater may include a power supply pattern electrically connecting the power supply terminal to the heating pattern, the power supply pattern including: a first pattern extending from the heating pattern along the long side direction to a position between the heating pattern and the recess; and a second pattern extending from the end of the first pattern on the power supply terminal side in a manner away from the end of the heater in the short side direction where the recess is located.

[0016] The plurality of power supply terminals may be respectively disposed at the center of the heater in the short-side direction, and the plurality of power supply terminals may be identical in size and shape.

[0017] Thus, the insulation distance between the power supply terminal and each end surface of the substrate in the short-side direction can be ensured, and the power supply terminal can be efficiently arranged so that the width of the heater in the short-side direction is minimized.

[0018] The holder may include a protrusion that protrudes from a surface opposite to a surface that supports the heater, and the engaging portion may be a groove that receives the protrusion.

[0019] Thereby, the strength of the holder can be improved compared with the case where the holder is provided with a groove, for example.

[0020] Effects of the Invention

[0021] According to the present invention, the connector can be well prevented from being offset in the longitudinal direction relative to the heater, and the width of the heater in the transverse direction can be narrowed while ensuring the insulation distance by staggering the recess and the power supply terminal in the longitudinal direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view showing a laser printer according to one embodiment of the present invention.

[0023] Figure 2 It is a cross-sectional view showing the fixing device.

[0024] Figure 3 (a) is a perspective view showing a heater in an exploded state, and (b) is a cross-sectional view of the heater.

[0025] Figure 4 (a) is a plan view of a holder holding a heater, and (b) is an enlarged view of both end portions of the holder.

[0026] Figure 5 is a partial rear view of the holder holding the heater.

[0027] Figure 6 It is an enlarged cross-sectional view of both end portions of the holder holding the heater, and is an enlarged cross-sectional view showing a state in which the connector sandwiches the heater and the holder at one end portion.

[0028] Figure 7 It is an exploded perspective view showing a state where the connector is removed from the holder holding the heater.

[0029] Explanation of symbols

[0030] 110 Heater

[0031] 120 retaining parts

[0032] 121 Supporting wall

[0033] 121A bearing surface

[0034] 122 side wall

[0035] 123 first contact part

[0036] 124 second contact portion

[0037] 125 convex part

[0038] 200 Connectors

[0039] 200B electrode

[0040] M substrate

[0041] M11 recess

[0042] PE power supply pattern

[0043] PH heating pattern

[0044] T power supply terminal DETAILED DESCRIPTION

[0045] Next, one embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

[0046] like Figure 1 As shown, the laser printer 1 mainly includes a supply unit 3 , an exposure device 4 , a process cartridge 5 , and a fixing device 8 in a housing 2 .

[0047] The supply unit 3 is provided at the lower part of the housing 2 and mainly includes a supply tray 31 for storing sheets S, a pressing plate 32 and a supply mechanism 33 . The sheets S stored in the supply tray 31 are moved upward by the pressing plate 32 and are supplied to the process cartridge 5 by the supply mechanism 33 .

[0048] The exposure device 4 is arranged at the upper part of the frame 2, and is provided with a light source device (not shown), a polygon mirror, a lens, a reflector, etc., which are shown with omitted symbols. In the exposure device 4, a light beam based on image data emitted from the light source device is scanned at high speed on the surface of the photosensitive drum 61, thereby exposing the surface of the photosensitive drum 61.

[0049] The process cartridge 5 is disposed below the exposure device 4 and can be attached to and detached from the frame 2 through an opening formed by opening a front cover 21 provided on the frame 2. The process cartridge 5 includes a drum unit 6 and a developing unit 7. The drum unit 6 mainly includes a photosensitive drum 61, a charger 62, and a transfer roller 63. The developing unit 7 can be attached to and detached from the drum unit 6 and mainly includes a developing roller 71, a supply roller 72, a layer thickness regulating blade 73, and a storage portion 74 for storing toner.

[0050] In the process cartridge 5, the surface of the photosensitive drum 61 is uniformly charged by the charger 62, and then exposed by the light beam from the exposure device 4, thereby forming an electrostatic latent image based on the image data on the photosensitive drum 61. In addition, the toner in the storage portion 74 is supplied to the developing roller 71 via the supply roller 72, enters between the developing roller 71 and the layer thickness regulating blade 73, and is carried on the developing roller 71 as a thin layer of a certain thickness. The toner carried on the developing roller 71 is supplied from the developing roller 71 to the electrostatic latent image formed on the photosensitive drum 61. As a result, the electrostatic latent image is converted into a visible image, and a toner image is formed on the photosensitive drum 61. Then, the toner image on the photosensitive drum 61 is transferred to the sheet S by conveying the sheet S between the photosensitive drum 61 and the transfer roller 63.

[0051] The fixing device 8 is arranged downstream of the process cartridge 5 in the conveying direction of the sheet S. The sheet S with the toner image transferred thereto passes through the fixing device 8, whereby the toner image is fixed. The sheet S with the toner image fixed thereto is discharged onto the discharge tray 22 by the conveying rollers 23 and 24.

[0052] like Figure 2 As shown, the fixing device 8 includes a heating unit 81 and a pressure roller 82. One of the heating unit 81 and the pressure roller 82 is urged toward the other by an urging mechanism (not shown).

[0053] The heating unit 81 includes a heater 110, a holder 120, a stay 130, and a belt 140. The heater 110 is a flat plate-shaped heater, and is supported by the holder 120. The structure of the heater 110 will be described in detail later.

[0054] The holder 120 is made of resin or the like and has a guide surface 120A that contacts the inner peripheral surface 141 of the belt 140 and guides the belt 140. The stay 130 is a member that supports the holder 120 and is formed by bending a plate material having greater rigidity than the holder 120, such as a steel plate, into a substantially U-shape in cross-sectional view.

[0055] The belt 140 is a heat-resistant and flexible endless belt, and has a metal tube made of a metal such as stainless steel and a fluororesin layer covering the metal tube. The heater 110, the holder 120, and the stay 130 are arranged inside the belt 140. The belt 140 is configured to rotate around the heater 110, the holder 120, and the stay 130.

[0056] The pressure roller 82 includes a metal shaft 82A and an elastic layer 82B covering the shaft 82A. The pressure roller 82 sandwiches the belt 140 with the heater 110 to form a nip portion NP for heating and pressurizing the sheet S.

[0057] The pressure roller 82 is configured to be driven and rotated by a driving force transmitted from a motor (not shown) provided in the housing 2, and by being driven and rotated, the belt 140 (or the sheet S) is driven and rotated by friction with the belt 140. Thus, the sheet S to which the toner image is transferred is conveyed between the pressure roller 82 and the heated belt 140, and the toner image is thermally fixed.

[0058] like Figure 3 (a) Figure 3 As shown in (b), the heater 110 is an elongated flat plate having a first surface 111 and a second surface 112 that are orthogonal to the urging direction of the heating unit 81 or the pressure roller 82 .

[0059] Hereinafter, the long side direction of the heater 110 is also referred to as the "long side direction", and the short side direction of the heater 110 is also referred to as the "short side direction". The long side direction of the heater 110 is the direction of the rotation axis of the pressure roller 82, that is, the direction in which the shaft 82A extends. The short side direction of the heater 110 is the conveying direction of the sheet S in the nip portion NP, and is the moving direction of the belt 140 in the nip portion NP.

[0060] The heater 110 has a recess 113. The recess 113 is a portion that contacts the holder 120 described later and restricts the movement of the heater 110 in the longitudinal direction. The recess 113 is provided at one end of the heater 110 in the longitudinal direction and is recessed from one end of the heater 110 in the transverse direction toward the transverse direction.

[0061] In this embodiment, the heater 110 is arranged so that the second surface 112 of the heater 110 faces the pressure roller 82. The heater 110 includes a substrate M, a first insulating layer G1, a second insulating layer G2, a heat generating pattern PH, a power supply pattern PE, a power supply terminal T, and a protective layer C.

[0062] The substrate M is an elongated flat plate made of metal such as stainless steel. The substrate M has a first surface M1 corresponding to the first surface 111 of the heater 110 and a second surface M2 corresponding to the second surface 112 of the heater 110. In addition, the substrate M has a recessed portion M11 constituting the recessed portion 113 of the heater 110. The substrate M is exposed at the end surface of the heater 110.

[0063] like Figure 3 (a) Figure 3 As shown in (b), the first insulating layer G1, the second insulating layer G2 and the protective layer C are made of an insulator such as a glass material. The first insulating layer G1 is formed on the first surface M1 of the substrate M. The second insulating layer G2 is formed on the second surface M2 of the substrate M.

[0064] The heat generating pattern PH, the power supply terminal T, and the power supply pattern PE are formed on the second insulating layer G2. That is, the heat generating pattern PH, the power supply terminal T, and the power supply pattern PE are provided on the substrate M via the second insulating layer G2.

[0065] The heating pattern PH is composed of a resistance heating element that generates heat when electricity is supplied. In the present embodiment, the heating pattern PH is formed into a U-shaped pattern extending along each end in the short-side direction and the other end in the long-side direction of the heater 110 .

[0066] The power supply terminal T is a terminal for supplying power to the heating pattern PH, and two are provided at one end of the long side direction of the heater 110. The power supply terminals T are arranged in the center of the short side direction of the heater 110 along the long side direction, and have the same size and shape. The power supply terminals T are connected to the heating pattern PH via the power supply pattern PE. The power supply terminals T can be connected to the connector 200 (see Figure 4 ) is connected to a power source (not shown) in the frame 2 via a connector 200. In the following description, the side far from the heating pattern PH is also referred to as the first power supply terminal T1, and the side close to the heating pattern PH is also referred to as the second power supply terminal T2.

[0067] The power supply pattern PE is a pattern for electrically connecting the power supply terminal T and the heating pattern PH. The power supply pattern PE includes a first power supply pattern PE1 connecting the first power supply terminal T1 and the heating pattern PH, and a second power supply pattern PE2 connecting the second power supply terminal T2 and the heating pattern PH. The power supply pattern PE and the power supply terminal T are made of a conductive material having a smaller resistance value than the heating pattern PH.

[0068] The protection layer C covers the power supply pattern PE and the heat generation pattern PH so that each power supply terminal T is exposed to the outside.

[0069] like Figure 4 As shown, the recess 113 is located between the heating pattern PH and the second power supply terminal T2 in the long side direction. In addition, in the long side direction, the distance between the recess 113 and the second power supply terminal T2 is smaller than the distance between the recess 113 and the heating pattern PH. In other words, the recess 113 is configured to be closer to the second power supply terminal T2 than the heating pattern PH. Moreover, the recess 113 is configured between the connector 200 described later and the heating pattern PH in the long side direction.

[0070] The distance L1 between the power supply terminal T and the end surface of the heater 110 is a distance greater than the distance (minimum insulation distance) at which discharge does not occur between the power supply terminal T and the substrate M exposed at the end surface of the heater 110. By setting the distance L1 to the minimum insulation distance, the width of the heater 110 can be narrowed. The shortest distance L2 between the power supply terminal T and the recess 113 is longer than the distance L1, that is, greater than the minimum insulation distance. As a result, discharge between the power supply terminal T and the end surface of the substrate M exposed in the recess 113 is suppressed.

[0071] The first power supply pattern PE1 has a first pattern PE11, a second pattern PE12, a third pattern PE13 and a fourth pattern PE14. The first pattern PE11 extends from the heating pattern PH along the long side direction to a position between the heating pattern PH and the recess 113 (M11). The second pattern PE12 extends from the end of the power supply terminal T side of the first pattern PE11 in a manner away from one end of the short side direction of the heater 110 where the recess 113 (M11) is located. The second pattern PE12 is inclined relative to the long side direction. The third pattern PE13 extends from the end of the power supply terminal T side of the second pattern PE12 through the second power supply terminal T2 and the other end of the short side direction of the heater 110 and is connected to the fourth pattern PE14. The fourth pattern PE14 extends from the end of the first power supply terminal T1 side of the third pattern PE13 along the short side direction to the first power supply terminal T1.

[0072] The second power supply pattern PE2 has a first pattern PE21, a second pattern PE22, and a third pattern PE23. The first pattern PE21 extends from the heating pattern PH along the long side direction to a position between the heating pattern PH and the recess 113 (M11). The second pattern PE22 extends from the end of the power supply terminal T side of the first pattern PE21 in a manner away from one end of the short side direction of the heater 110 where the recess 113 (M11) is located. The second pattern PE22 is inclined relative to the long side direction. The third pattern PE23 extends from the end of the power supply terminal T side of the second pattern PE22 along the long side direction to the second power supply terminal T2.

[0073] Next, the structure of the holder 120 will be described.

[0074] like Figure 4 as well as Figure 6 As shown, the holder 120 has a support wall 121 , a side wall 122 , a first contact portion 123 , a second contact portion 124 , a convex portion 125 , and a protruding portion 126 .

[0075] The support wall 121 has a support surface 121A that supports the heater 110 . The support surface 121A is in contact with the first surface 111 of the heater 110 .

[0076] The side wall 122 protrudes from the support surface 121A and is provided along the periphery of the support wall 121. The side wall 122 includes a first side wall 122A, a second side wall 122B, a third side wall 122C, and a fourth side wall 122D. The first side wall 122A is located at one end of the long side direction of the support wall 121 and extends along the short side direction. The second side wall 122B is located at the other end of the long side direction of the support wall 121 and extends along the short side direction. The third side wall 122C is located at one end of the short side direction of the support wall 121 and extends along the long side direction. The fourth side wall 122D is located at the other end of the short side direction of the support wall 121 and extends along the long side direction.

[0077] The first contact portion 123 is provided so as to protrude in the longitudinal direction from the first side wall 122A toward the second side wall 122B and to be able to contact the second surface 112 of the heater 110. That is, the first contact portion 123 is opposite to the second surface 112 of the heater 110 in the direction orthogonal to the surface 111 of the heater 110. The first contact portion 123 can contact the second surface 112 of the heater 110 over a first distance L3 in the longitudinal direction. The first distance L3 is the distance in the longitudinal direction between the end surface 123A of the first contact portion 123 facing the second side wall 122B and the end surface 110A of the end surfaces 110A and 110B in the longitudinal direction of the heater 110, whichever has the smaller distance from the first contact portion 123. Hereinafter, the direction orthogonal to the surface 111 of the heater 110 is also referred to as the "orthogonal direction".

[0078] The second contact portion 124 is separated from the first contact portion 123 in the longitudinal direction. The second contact portion 124 is configured to protrude from the second side wall 122B toward the first contact portion 123 in the longitudinal direction and to be able to contact the second surface 112 of the heater 110. That is, the second contact portion 124 is opposite to the second surface 112 of the heater 110 in the orthogonal direction. The second contact portion 124 can contact the second surface 112 of the heater 110 over a second distance L4 in the longitudinal direction. The second distance L4 is a distance along the longitudinal direction between an end surface 124A of the second contact portion 124 facing the first contact portion 123 and an end surface 110B of the heater 110 that is smaller in distance from the second contact portion 124, of the end surfaces 110A and 110B in the longitudinal direction.

[0079] The first distance L3 is smaller than the second distance L4. That is, when viewed from the orthogonal direction, the length (overlapping amount) of the first contact portion 123 overlapping the heater 110 is shorter than the length of the second contact portion 124 overlapping the heater 110.

[0080] like Figure 4 As shown, there are two first contact portions 123 , each of which overlaps with a corner of one end portion in the longitudinal direction of the heater 110 .

[0081] In addition, there are two second contact portions 124 , each of which overlaps with a corner portion of the other end portion of the heater 110 .

[0082] The holder 120 is an elongated member extending in the longitudinal direction. The holder 120 is slightly larger than the heater 110 and surrounds the heater 110 with the side walls 122 to hold the heater 110. The holder 120 has the above-mentioned guide surfaces 120A at both ends in the lateral direction.

[0083] The projection 125 extends from the third side wall 122C toward the fourth side wall 122D in the short-side direction. The projection 125 enters the recess 113 of the heater 110. The projection 125 contacts the recess 113 of the heater 110 in the long-side direction and functions to restrict the movement of the heater 110 in the long-side direction.

[0084] The projection 125 is provided at the same longitudinal end of the holder 120 as the first contact portion 123. That is, the longitudinal distance between the projection 125 and the first contact portion 123 is smaller than the longitudinal distance between the projection 125 and the second contact portion 124.

[0085] like Figure 6 , Figure 7 As shown, the protrusion 126 protrudes from a surface 121B of the support wall 121 on the side opposite to the support surface 121A at one end of the long side direction of the retainer 120. The protrusion 126 is provided at the approximate center of the long side direction within the range of the long side direction of the connector 200 described later, and extends in the short side direction (see Figure 5 ).

[0086] Next, the structure of the connector 200 will be described.

[0087] The connector 200 is a component for supplying power to the heater 110. The connector 200 also functions as a fixing component for fixing a part of the heater 110 to the holder 120. The connector 200 is attached to the heater 110 and one end of the holder 120 from one side in the short side direction of the heater 110. The connector 200 includes a connector body 200A made of resin or the like and two electrodes 200B made of a conductive material such as metal.

[0088] The electrodes 200B are connected to the power supply terminals T of the heater 110 and are arranged at intervals in the longitudinal direction. The electrodes 200B are connected to a power source (not shown) via wiring (not shown).

[0089] The connector body 200A has a rectangular parallelepiped base portion 210 and a first extension portion 211 and a second extension portion 212 extending from the base portion 210 toward the heater 110. The first extension portion 211 and the second extension portion 212 are arranged at intervals in the orthogonal direction. The first extension portion 211 and the second extension portion 212 sandwich the heater 110 and the holder 120 in the orthogonal direction.

[0090] A groove 213 as an engagement portion is provided on the surface of the second extension portion 212 facing the first extension portion 211. The groove 213 receives the protrusion 126 and contacts the protrusion 126 in the longitudinal direction to restrict the movement of the connector 200 relative to the holder 120 in the longitudinal direction.

[0091] The connector 200 is disposed between the first contact portion 123 and the protrusion 125 in the longitudinal direction. That is, the distance between the connector 200 and the first contact portion 123 in the longitudinal direction is smaller than the distance between the connector 200 and the second contact portion 124 in the longitudinal direction.

[0092] Next, the effects of the fixing device 8 according to the present embodiment will be described.

[0093] When assembling the fixing device 8, first, the heater 110 is mounted on the holder 120. At this time, the other end of the long side direction of the heater 110 is inserted into the second contact portion 124, and one end of the long side direction of the heater 110 is inserted into the first contact portion 123 while the heater 110 is bent, thereby making it easy to mount the heater 110 on the holder 120. In addition, at this time, the concave portion 113 of the heater 110 is engaged with the convex portion 125 of the holder 120.

[0094] Next, the holder 120 is placed on the heating unit 81. Figure 2 As shown, the second surface 112 of the heater 110 is arranged downwardly in a manner facing the pressure roller 82, so that the heater 110 is bent in the orthogonal direction in a manner that the two ends in the long-side direction are in contact with the contact parts 123 and 124 and the center in the long-side direction is convex downward. The concave part 113 of the heater 110 and the convex part 125 of the holder 120 are arranged at positions close to the first contact part 123, so that the reduction in the overlap amount of the heater 110 is smaller at the end on the first contact part 123 side than at the end on the second contact part 124 side. Therefore, even if the overlap amount of the first contact part 123 is short, the heater 110 can be reliably held on the holder 120.

[0095] When power is supplied to the heater 110 in order to perform printing, power is supplied to the heating pattern PH via the power supply terminal T and the power supply pattern PE, and the heating pattern PH generates heat. In addition, due to the heat from the heating pattern PH, the heater 110 and the holder 120 thermally expand in the long side direction. The linear expansion coefficient of the holder 120 composed of resin or the like is larger than the linear expansion coefficient of the heater 110 composed of metal or the like. On the other hand, the thermal conductivity of the heater 110 is greater than the thermal conductivity of the holder 120, and the heater 110 has the heating pattern PH, so the temperature of the heater 110 is easier to rise than the temperature of the holder 110. Due to these factors, there is a difference in the amount of thermal expansion between the holder 120 and the heater 110, and the connector 200 positioned on the holder 120 and the power supply terminal T of the heater 110 will be offset in the long side direction. In this embodiment, since the recess 113 is arranged close to the power supply terminal T, the offset of the position of the power supply terminal T based on the convex portion 125 and the position of the electrode 200B of the connector 200 can be suppressed to be relatively small.

[0096] Based on the above, the following effects can be obtained in this embodiment.

[0097] By positioning the connector 200 on the heater 110 via the holder 120, the displacement of the connector 200 relative to the heater 110 in the long-side direction can be well suppressed, and the recess 113 of the heater 110 can be arranged to be offset from the power supply terminal T in the long-side direction. By arranging the recess 113 in this way, a sufficient insulation distance can be ensured between the end surface of the substrate M exposed in the recess 113 and the power supply terminal T, and the width of the heater 110 in the short-side direction can be narrowed. As a result, the material cost can be suppressed and the electric heating efficiency can be improved.

[0098] By providing the recess 113 between the connector 200 and the heat generating pattern PH in the longitudinal direction, the recess 113 can be further away from the power supply terminal T, and the insulation distance can be further ensured.

[0099] By making the distance between the recess 113 and the second power supply terminal T2 smaller than the distance between the recess 113 and the heating pattern PH, the convex portion 125 of the retaining member 120 in contact with the recess 113 and the portion of the retaining member 120 in contact with the locking portion of the connector 200 are arranged to be close to each other, thereby better suppressing the displacement of the connector 200 relative to the heater 110 in the long side direction.

[0100] By arranging the power supply terminals T at the center of the short side direction of the heater 110 and making them the same size and shape, the insulation distance between the power supply terminals T and the end faces of the substrate M in the short side direction can be ensured, and the power supply terminals T can be efficiently configured in a manner that minimizes the width of the short side direction of the heater 110.

[0101] By providing the protrusion 126 on the holder 120 and providing the groove 213 on the connector 200 , the strength of the holder 120 can be improved compared to, for example, a case where the groove is provided on the holder 120 .

[0102] By making the distance between the connector 200 and the first contact portion 123 in the longitudinal direction smaller than the distance between the connector 200 and the second contact portion 124 in the longitudinal direction, the heater 110 can be more reliably held on the holder 120 at the first contact portion 123 side by the holding force of the connector 200 .

[0103] By providing the connector 200 between the first contact portion 123 and the convex portion 125 in the longitudinal direction, the heater 110 can be more reliably held on the holder 120 at the first contact portion 123 side by the holding force of the connector 200 .

[0104] In addition, the present invention is not limited to the above-mentioned embodiment but can be used in various forms.

[0105] In the above embodiment, the heater 110 is mounted on the holder 120 using two contact portions 123 and 124, but the first contact portion 123 may not be provided. In this case, the heater 110 can be held on the holder 120 using the second contact portion 124 and the connector 200 as a fixing member separated from the second contact portion 124 in the longitudinal direction. In addition, the fixing member may be an adhesive or the like. In such a structure, only one member is required for mounting the heater 110 on the holder 120, so the heater 110 can be easily mounted on the holder 120.

[0106] In the above embodiment, the protrusion is provided on the holder 120 side and the groove is provided on the connector 200 side. However, the protrusion may be provided on the connector 200 and the groove may be provided on the holder 120 .

[0107] In addition, in the above embodiment, the contact parts 123 and 124 are respectively provided with two, but the contact parts 123 and 124 may be provided with one or more than three. In addition, the contact parts 123 and 124 only need to extend over at least a portion of the short side direction of the heater 110, and are not limited to the corners of the heater 110. Furthermore, in the present embodiment, although the contact parts 123 and 124 extend in the long side direction from the first side wall 122A and the second side wall 122B, respectively, they may be separated from the first side wall 122A and the second side wall 122B and extend in the short side direction from the third side wall 122C and the fourth side wall 122D.

[0108] Furthermore, in the above-mentioned embodiment, although the side wall 122 is continuously provided along the periphery of the supporting wall 121, the side wall 122 may be discontinuously provided along the supporting wall 121. For example, the side wall 122 may also include a plurality of side walls that are separately arranged. In this case, the heater 110 may also be held by the holder 120. In addition, in the case where the contact portions 123 and 124 extend from the third side wall 122C and the fourth side wall 122D, the first side wall 122A and the second side wall 122B may not exist.

[0109] The respective elements described in the above-mentioned embodiment and modified examples may be arbitrarily combined and implemented.

Claims

1. A fixing device, characterized in that: Equipped with a heater, a holder and a connector, The heater is a flat plate heater and has: a metal substrate having a concave portion; a heating pattern, the heating pattern being composed of a resistive heating element disposed on the substrate; and a plurality of power supply terminals, the plurality of power supply terminals being electrically connected to the heat generating pattern and being disposed at one end portion in the long side direction of the heater, The holder has a convex portion that contacts the concave portion in the longitudinal direction and supports the heater. The connector includes an electrode connected to the power supply terminal and an engaging portion engaged with the holder in the longitudinal direction. The recessed portion is provided in the long-side direction between the heat generating pattern and a power supply terminal closest to the heat generating pattern among the plurality of power supply terminals. A shortest distance between a power supply terminal closest to the heat generating pattern among the plurality of power supply terminals and the recessed portion is longer than a distance between the power supply terminal and an end surface of the heater.

2. The fixing device according to claim 1, characterized in that: The recessed portion is provided between the connector and the heat generating pattern in the long side direction.

3. The fixing device according to claim 1 or 2, characterized in that: A distance between the recess and the power supply terminal closest to the heat generating pattern among the plurality of power supply terminals is smaller than a distance between the recess and the heat generating pattern.

4. The fixing device according to claim 1 or 2, characterized in that: The heater includes a power supply pattern that electrically connects the power supply terminal and the heat generation pattern. The power supply pattern comprises: a first pattern extending from the heating pattern along the long side direction to a position between the heating pattern and the recess; and a second pattern extending from the end of the first pattern on the power supply terminal side in a manner away from the end of the heater in the short side direction where the recess is located.

5. The fixing device according to claim 1 or 2, characterized in that: The plurality of power supply terminals are respectively disposed at the center of the heater in the short-side direction, and the plurality of power supply terminals have the same size and shape.

6. The fixing device according to claim 1 or 2, characterized in that: The holder has a protrusion protruding from a surface opposite to a surface supporting the heater. The engaging portion is a groove that receives the protruding portion.

Images