Heater and image forming apparatus

Abstract

To provide a heater capable of achieving downsizing even if terminals are collected in the vicinity of one end of a substrate, and an image formation device.SOLUTION: A heater according to an embodiment comprises: a first insulation part provided on a first surface of a conductive substrate and extending in a first direction; a heat generator provided on the first insulation part and extending in the first direction; a first terminal electrically connected to an end of the heat generator in the vicinity of one end of the substrate; a second insulation part provided on a second surface of the substrate and extending in the first direction; a detection part capable of detecting the temperature of the substrate; a second terminal electrically connected to the detection part in the vicinity of an end at a side where the first terminal of the substrate is provided; and pattern wiring provided on the second insulation part, having one end electrically connected to the detection part and the other end electrically connected to the substrate outside the second insulation part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a heater and an image forming apparatus.

Background Art

[0002] Image forming apparatuses such as copying machines and printers are provided with a heater for fixing toner. Heaters are also provided in printing and erasing apparatuses installed in rewritable card readers / writers and the like. Generally, such a heater includes an elongated substrate, a heating element provided on one surface of the substrate and extending in the longitudinal direction of the substrate, and terminals electrically connected to respective end portions of the heating element on both sides.

[0003] Here, in a heater having an elongated substrate, the temperature in the longitudinal direction of the heater is likely to vary. Variations in temperature in the longitudinal direction of the heater tend to cause uneven heating in an object to be heated. For this reason, there are cases where a plurality of thermistors are provided on the surface of the substrate opposite to the side where the heating element is provided, and the temperature of the heating element is controlled using the plurality of thermistors.

[0004] Further, in recent years, in order to simplify the routing of a harness electrically connected to the heater and facilitate the wiring work of the harness, it has been desired to collect terminals electrically connected to a heating element and terminals electrically connected to a plurality of thermistors near one end portion in the longitudinal direction of the substrate. In this case, in order to collect the terminals near one end portion of the substrate, it is necessary to fold back the patterned wiring electrically connected to the heater and the thermistors toward the one end portion side of the substrate.

[0005] However, when a plurality of patterned wirings are folded back toward the one end portion side of the substrate, the number of patterned wirings aligned in the lateral direction of the substrate increases. As the number of patterned wirings aligned in the lateral direction of the substrate increases, the dimension in the lateral direction of the substrate (the width dimension of the substrate) increases.

[0006] Therefore, concentrating the terminals near one end of the circuit board increased the width of the board, making it difficult to miniaturize the heater. Therefore, there was a need to develop a technology that would allow for miniaturization of the heater even if the terminals were concentrated near one end of the circuit board. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2003-131502 [Overview of the project] [Problems that the invention aims to solve]

[0008] The problem that this invention aims to solve is to provide a heater and an image forming apparatus that can be miniaturized even if the terminals are concentrated near one end of the substrate. [Means for solving the problem]

[0009] The heater according to the embodiment comprises: a conductive substrate extending in a first direction; a first insulating portion provided on a first surface of the substrate, which is insulating and extends in the first direction; a heating element provided on the first insulating portion and extending in the first direction; a first terminal provided on the first insulating portion near one end of the substrate in the first direction and electrically connected to the end of the heating element; a second insulating portion provided on a second surface of the substrate facing the first surface, which is insulating and extends in the first direction; a detection unit provided on the second insulating portion and capable of detecting the temperature of the substrate; a second terminal provided on the second insulating portion near the end of the substrate on the side where the first terminal is provided and electrically connected to the detection unit; and a pattern wiring provided on the second insulating portion, extending in the first direction, with one end electrically connected to the detection unit and the other end electrically connected to the substrate outside the second insulating portion. [Effects of the Invention]

[0010] According to embodiments of the present invention, it is possible to provide a heater and an image forming apparatus that can be miniaturized even if the terminals are concentrated near one end of the substrate. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of the heater according to this embodiment, as viewed from one side in the Z direction. [Figure 2] This is a schematic diagram of the heater as viewed from the other side in the Z direction. [Figure 3] This is a schematic cross-sectional view of the heater in the direction of line AA in Figure 1. [Figure 4] This is a schematic diagram illustrating the wiring of the detection unit in the comparative example. [Figure 5] This is a schematic diagram of a heater according to another embodiment, viewed from one side in the Z direction. [Figure 6] This is a schematic diagram of the heater as viewed from the other side in the Z direction. [Figure 7] This is a schematic diagram illustrating an image forming apparatus according to this embodiment. [Figure 8] This is a schematic diagram illustrating the fixing section. [Modes for carrying out the invention]

[0012] The embodiments will be illustrated below with reference to the drawings. In each drawing, similar components are denoted by the same reference numerals, and detailed explanations will be omitted as appropriate. Also, the arrows X, Y, and Z in each drawing represent three mutually orthogonal directions. For example, the longitudinal direction of the substrate is the X direction (corresponding to an example of the first direction), the short direction (width direction) of the substrate is the Y direction (corresponding to an example of the second direction), and the direction perpendicular to the surface of the substrate is the Z direction.

[0013] (heater) FIG. 1 is a schematic diagram of the heater 1 according to the present embodiment when viewed from one side in the Z direction. FIG. 2 is a schematic diagram of the heater 1 when viewed from the other side in the Z direction. FIG. 3 is a schematic cross-sectional view of the heater 1 in FIG. 1 along the line A-A. As shown in FIGS. 1 to 3, the heater 1 includes, for example, a substrate 10, an insulating portion 20 (corresponding to an example of a first insulating portion), a heating element 30, a wiring 40, a protective portion 50, an insulating portion 60 (corresponding to an example of a second insulating portion), a detection portion 70, a wiring 80, and a protective portion 90.

[0014] The substrate 10 has a plate shape, and includes a surface 10a (corresponding to an example of a first surface) and a surface 10b opposite to the surface 10a (corresponding to an example of a second surface). The substrate 10 has a shape extending in one direction (for example, the X direction). The planar shape of the substrate 10 is, for example, an elongated rectangle. The thickness of the substrate 10 is, for example, about 0.3 mm to 1.0 mm. The width dimension W of the substrate 10 (dimension in the transverse direction; dimension in the Y direction) is, for example, about 5 mm to 15 mm. The length L of the substrate 10 (dimension in the longitudinal direction; dimension in the X direction) can be appropriately changed according to the size of an object to be heated (for example, paper) and the like.

[0015] The substrate 10 is formed of a material having heat resistance and conductivity. Generally, a substrate is formed of an insulating material (for example, ceramics such as aluminum oxide), but the heater 1 according to the present embodiment is provided with the substrate 10 containing, for example, a metal. The metal is, for example, stainless steel, an aluminum alloy, or the like.

[0016] As shown in FIG. 1 and FIG. 3, the insulating portion 20 has insulating properties and is provided on the surface 10a of the substrate 10. The insulating portion 20 extends in the longitudinal direction of the substrate 10 (X direction). The insulating portion 20 is provided to insulate between the conductive substrate 10 and the heating element 30 as well as the wiring 40. Therefore, the insulating portion 20 covers, on the surface 10a of the substrate 10, a region where the heating element 30 and the wiring 40 are provided. The insulating portion 20 is formed of a material having heat resistance and insulating properties. The insulating portion 20 can be formed of, for example, an inorganic material such as ceramics or glass material. The insulating portion 20 can be formed by, for example, thermal spraying or firing.

[0017] The heating element 30 converts applied electric power into heat (Joule heat). The heating element 30 is provided on the insulating portion 20 (the surface of the insulating portion 20 on the opposite side from the substrate 10 side). The heating element 30 extends, for example, in the longitudinal direction of the substrate 10 (X direction). The heating element 30 is formed using, for example, ruthenium oxide (RuO₂), a silver-palladium (Ag-Pd) alloy, or the like. The heating element 30 can be formed, for example, by applying a paste-like material onto the insulating portion 20 using a screen printing method or the like, and then curing the material using a firing method or the like.

[0018] The wiring 40 is provided on the insulating portion 20. The wiring 40 includes a terminal 41 (corresponding to an example of a first terminal) and a patterned wiring 42. For example, two terminals 41 can be provided for one heating element 30 or a plurality of heating elements 30 connected in series. The two terminals 41 are provided on the insulating portion 20 near one end of the substrate 10 in the longitudinal direction (X direction). The two terminals 41 can be arranged side by side in the lateral direction of the substrate 10 (Y direction) with a predetermined gap therebetween. That is, in the heater 1 according to the present embodiment, the two terminals 41 are concentrated near one end of the substrate 10.

[0019] One terminal 41 is electrically connected to one end of the heating element 30. The terminal 41 and the heating element 30 may be directly connected, or a patterned wiring may be provided between the terminal 41 and the heating element 30. The other terminal 41 is electrically connected to the other end of the heating element 30 via a patterned wiring 42.

[0020] As shown in Figure 1, the pattern wiring 42 is folded back toward the end of the substrate 10 on the side where the terminal 41 is located. For example, the pattern wiring 42 has a portion 42a and a portion 42b. Portion 42a is electrically connected to the end of the heating element 30 opposite to the side to which the terminal 41 is connected. Portion 42a extends, for example, in the short direction (Y direction) of the substrate 10. Portion 42b extends, for example, in the longitudinal direction (X direction) of the substrate 10. One end of portion 42b is electrically connected to the other terminal 41. The other end of portion 42b is electrically connected to the end of portion 42a opposite to the side to which the heating element 30 is electrically connected.

[0021] The terminal 41 and the pattern wiring 42 (parts 42a and 42b) can be formed integrally. The wiring 40 (terminal 41 and pattern wiring 42) is formed from a material that has conductivity and heat resistance. For example, the wiring 40 is formed using a material containing silver or copper. For example, the wiring 40 can be formed by applying a paste-like material onto the insulating part 20 using a screen printing method or the like, and then curing it using a firing method or the like.

[0022] The protective section 50 has, for example, the function of insulating the heating element 30 and the pattern wiring 42, the function of transferring the heat generated in the heating element 30 to the outside, and the function of protecting the heating element 30 and the pattern wiring 42 from external forces, corrosive gases, etc. The protective section 50 is, for example, provided on the insulating section 20 and covers the heating element 30 and the pattern wiring 42 (parts 42a and 42b). In this case, the terminal 41 is exposed from the protective section 50.

[0023] The protective part 50 is formed from a material that has heat resistance and insulation properties, as well as high chemical stability and thermal conductivity. For example, the protective part 50 is formed from an inorganic material such as ceramics or glass. In this case, the protective part 50 can also be formed using a glass material to which a filler containing a material with high thermal conductivity, such as aluminum oxide, has been added. The thermal conductivity of the glass material to which the filler has been added can be, for example, 2 [W / (m·K)] or more.

[0024] The protective section 50 can be formed, for example, by applying a paste-like material onto the insulating section 20, the heating element 30, and the pattern wiring 42 using a screen printing method, and then curing it using a firing method. In this case, the two terminals 41 are exposed from the protective section 50.

[0025] As shown in Figures 2 and 3, the insulating portion 60 has insulating properties and is provided on the surface 10b of the substrate 10. The insulating portion 60 extends in the longitudinal direction (X direction) of the substrate 10. The insulating portion 60 is provided to insulate the conductive substrate 10 from the detection portion 70 and the wiring 80. Therefore, the insulating portion 60 covers the area of ​​the surface 10b of the substrate 10 where the detection portion 70 and the wiring 80 are provided. The insulating portion 60 is formed from a material that has heat resistance and insulating properties. The material and formation method of the insulating portion 60 can be the same as the material and formation method of the insulating portion 20 described above.

[0026] The detection unit 70 detects the temperature of the substrate 10. The detection unit 70 can be, for example, a thermistor, thermocouple, or resistance thermometer. The detection unit 70 illustrated in Figures 2 and 3 is a thermistor. At least one detection unit 70 is provided on the insulating unit 60. The heater 1 illustrated in Figures 2 and 3 is provided with two detection units 70.

[0027] As shown in Figure 2, the multiple detection units 70 are provided at predetermined intervals in the longitudinal direction (X direction) and the short direction (Y direction) of the substrate 10. If the multiple detection units 70 are provided at predetermined intervals in the longitudinal direction (X direction) and the short direction (Y direction) of the substrate 10, it is possible to detect variations in the in-plane temperature of the substrate 10, and consequently, variations in the in-plane temperature of the heater 1. Therefore, for example, the power applied to the heating element 30 can be controlled so that the temperature variation in the longitudinal direction (X direction) of the substrate 10 is reduced. The number, spacing, and arrangement of the detection units 70 can be appropriately changed according to the size of the heater 1 (substrate 10) and the specifications of the heater 1 (e.g., heating temperature, range of allowable temperature variation). The number, spacing, and arrangement of the detection units 70 can be appropriately determined, for example, by conducting experiments or simulations.

[0028] As shown in Figure 2, the wiring 80 has, for example, terminals 81 (corresponding to an example of a second terminal) and patterned wirings 82a to 82d. Terminals 81 and patterned wirings 82a to 82d can be formed integrally. The material and formation method of the wiring 80 can be, for example, the same as the material and formation method of the wiring 40 described above. The number of terminals 81 and the number of patterned wirings 82a to 82d can be appropriately changed according to the number of detection units 70.

[0029] For example, one terminal 81 can be provided for each detection unit 70. The terminal 81 is electrically connected to the detection unit 70. The heater 1 illustrated in Figures 2 and 3 is provided with two detection units 70, and therefore has two terminals 81. The two terminals 81 are provided on the insulating portion 60 near the end of the substrate 10 on the side where the terminals 41 are provided. The two terminals 81 can be provided side by side in the short direction (Y direction) of the substrate 10 with a predetermined distance between them. That is, in the heater 1 according to this embodiment, the two terminals 81 are concentrated near one end of the substrate 10. Further details regarding pattern wiring 82a to 82d will be described later.

[0030] As shown in Figure 2, the protective section 90 is provided, for example, on top of the insulating section 60 and covers the detection section 70 and the pattern wiring 82a to 82d. In this case, the terminal 81 is exposed from the protective section 90.

[0031] The protective section 90 has, for example, the function of insulating the detection section 70 and the pattern wiring 82a to 82d, and the function of protecting the detection section 70 and the pattern wiring 82a to 82d from external forces, corrosive gases, etc. The material and forming method of the protective section 90 can be the same as those of the protective section 50 described above.

[0032] Here, when heater 1 is used or during the manufacturing of heater 1 (for example, during firing of the protective part 90), thermal stress is generated due to the difference in the thermal expansion coefficients of the materials. As a result, there is a risk that heater 1 may warp due to thermal stress. If heater 1 warps, the distance between heater 1 and the object to be heated will vary, which may cause uneven heating of the object.

[0033] In the heater 1 according to this embodiment, as shown in Figure 3, an insulating part 20, a heating element 30, wiring 40, and a protective part 50 are provided on the surface 10a side of the substrate 10. An insulating part 60, a detection part 70, wiring 80, and a protective part 90 are provided on the surface 10b side of the substrate 10. The material of the insulating part 60 can be the same as the material of the insulating part 20. The material of the protective part 90 can be the same as the material of the protective part 50.

[0034] Therefore, the thermal stress generated on the surface 10a side of the substrate 10 by the substrate 10, the insulating part 20, and the protective part 50 can be offset by the thermal stress generated on the surface 10b side of the substrate 10 by the substrate 10, the insulating part 60, and the protective part 90. If the thermal stresses are offset, warping of the heater 1 can be suppressed.

[0035] For example, if the thickness of the insulating part 20 and the thickness of the insulating part 60 are made to be approximately the same, and the thickness of the protective part 50 and the thickness of the protective part 90 are made to be approximately the same, the value of the thermal stress generated on the surface 10a side of the substrate 10 and the value of the thermal stress generated on the surface 10b side of the substrate 10 can be made to be approximately the same. Therefore, warping of the heater 1 can be effectively suppressed.

[0036] Furthermore, for example, even if the sum of the thickness of the insulating part 20 and the protective part 50 is made to be approximately the same as the sum of the thickness of the insulating part 60 and the protective part 90, the value of the thermal stress generated on the surface 10a of the substrate 10 and the value of the thermal stress generated on the surface 10b of the substrate 10 can be made to be approximately the same. Therefore, warping of the heater 1 can be effectively suppressed.

[0037] Next, we will further explain the pattern wiring 82a to 82d. First, the wiring of the detection unit 70 in the comparative example will be described. Figure 4 is a schematic diagram illustrating the wiring of the detection unit 70 in a comparative example. As shown in Figure 4, the insulating portion 61 has insulating properties and is provided on the surface 11b of the substrate 11. The detection portion 70 is provided on the insulating portion 61. The number, spacing, and arrangement of the detection portions 70 can be the same as those illustrated in Figure 2.

[0038] There are three terminals 83. One of the three terminals 83 is common to the two detection units 70. The three terminals 83 are located near one end of the substrate 11 in the longitudinal direction (X direction). The three terminals 83 are arranged in the short direction (Y direction) of the substrate 11 with a predetermined interval between them.

[0039] One detection unit 70 is electrically connected to one terminal 83 via pattern wiring 84a. The other detection unit 70 is electrically connected to another terminal 83 via pattern wiring 84b. Furthermore, the two detection units 70 are electrically connected to the remaining terminals 83 via a common pattern wiring 84c.

[0040] The two detection units 70 and the pattern wiring 84a to 84c are covered by the protective unit 91. The three terminals 83 are exposed from the protective unit 91.

[0041] Even in this way, the two detection units 70 can be wired. However, as can be seen from Figure 4, in this way, the three pattern wirings 84a to 84c that extend in the longitudinal direction (X direction) of the substrate 11 will be aligned in the short direction (Y direction) of the substrate 11. As a result, the width dimension W1 of the substrate 11 (dimension in the short direction; dimension in the Y direction) becomes larger. When the width dimension W1 of the substrate 11 becomes larger, it becomes difficult to miniaturize the heater.

[0042] Therefore, in the heater 1 according to this embodiment, the conductive substrate 10 is used as a common wiring to the two detection units 70. As shown in Figure 2, the pattern wiring 82a is provided on the insulating portion 60 and is electrically connected to the terminal 81 and the detection portion 70. The pattern wiring 82b is provided on the insulating portion 60, and one end of it is electrically connected to the detection portion 70 to which the pattern wiring 82a is electrically connected. The pattern wiring 82b extends in the longitudinal direction (X direction) of the substrate 10, and the end opposite to the detection portion 70 is electrically connected to the substrate 10 outside the insulating portion 60.

[0043] The pattern wiring 82c is provided on the insulating portion 60 and is electrically connected to the terminal 81 and the detection portion 70. The pattern wiring 82d is provided on the insulating portion 60, and one end of it is electrically connected to the detection portion 70 to which the pattern wiring 82c is electrically connected. The pattern wiring 82d extends in the longitudinal direction (X direction) of the substrate 10, and the end opposite to the detection portion 70 is electrically connected to the substrate 10 outside the insulating portion 60.

[0044] The materials and formation methods for terminal 81 and pattern wiring 82a to 82d can be the same as those for terminal 41 and pattern wiring 42 described above.

[0045] Furthermore, as shown in Figure 2, in the longitudinal direction (X direction) of the substrate 10, the vicinity of the end of the surface 10b of the substrate 10 on the side where the terminal 81 is provided is exposed from the insulating portion 60. As mentioned above, the substrate 10 is made of a conductive material. Also, the ends of the wirings 82b and 82d are electrically connected to the surface 10b of the substrate 10 outside the insulating portion 60. Therefore, the substrate 10 functions as wiring and terminals electrically connected to the detection unit 70 (wirings 82b and 82d). For example, as shown in Figure 2, the vicinity of the end of the substrate 10 on the side where the terminal 81 is provided functions as terminal 81a electrically connected to the detection unit 70 via wirings 82b and 82d.

[0046] As shown in Figures 1 and 2, if terminals 41, 81, and 81a are located near the same end of the substrate 10 in the longitudinal direction (X direction), the heater 1 and external equipment can be electrically connected with a single harness. This simplifies harness routing, reduces wiring space, simplifies harness wiring work, and shortens wiring time.

[0047] Furthermore, since the conductive substrate 10 functions as wiring electrically connected to the detection unit 70 (wirings 82b and 82d), there is no need to fold the wirings 82b and 82d back towards the terminal 81. As a result, the dimensions of the substrate 10 in the short direction (Y direction) can be reduced, which allows for miniaturization of the heater 1.

[0048] Figure 5 is a schematic diagram of heater 1a according to another embodiment, as viewed from one side in the Z direction. Figure 6 is a schematic diagram of the heater 1a as viewed from the other side in the Z direction. As shown in Figures 5 and 6, the heater 1a includes, for example, a substrate 10, an insulating part 20, heating elements 30, 30a, 30b, wiring 43, a protective part 50, an insulating part 60, a detection part 70, wiring 85, and a protective part 90. In other words, heater 1a can be made by adding heating elements 30a and 30b to the aforementioned heater 1 and increasing the number of detection units 70 to four.

[0049] The heating elements 30, 30a, and 30b are arranged at predetermined intervals along the short side (Y direction) of the substrate 10. The lengths of the heating elements 30a and 30b in the longitudinal direction (X direction) of the substrate 10 are shorter than the length of the heating element 30. In the short side (Y direction) of the substrate 10, heating element 30a is provided on one side of heating element 30, and heating element 30b is provided on the other side of heating element 30. In the longitudinal direction (X direction) of the substrate 10, heating element 30a is provided near the end of heating element 30 opposite to the terminal 41 side. Heating element 30b is provided near the end of heating element 30 on the terminal 41 side. The materials and forming methods of the heating elements 30a and 30b can be, for example, the same as the materials and forming methods of heating element 30 described above.

[0050] The terminal 41 and the pattern wiring 43 are provided on the insulating portion 20. The terminal 41 and the pattern wiring 43 can be formed integrally. The material and forming method of the terminal 41 and the pattern wiring 43 can be the same as, for example, the material and forming method of the terminal 41 and the pattern wiring 42 described above.

[0051] There are four terminals 41. One terminal 41 is provided for each of the heating elements 30, 30a, and 30b. In addition, one terminal 41 is provided common to the heating elements 30, 30a, and 30b. The four terminals 41 are located near one end of the substrate 10 in the longitudinal direction (X direction). The four terminals 41 can be arranged in a line along the short direction (Y direction) of the substrate 10 with a predetermined interval between them. That is, in heater 1a, the four terminals 41 are concentrated near one end of the substrate 10.

[0052] The pattern wiring 43 has portions 42a1, 42b, 42b1, and 42b2. Portion 42a1 is located in the longitudinal direction (X direction) of the substrate 10, near the end of the substrate 10 opposite to the side where the terminals 41 are provided. Portion 42a1 extends in the short direction (Y direction) of the substrate 10.

[0053] Part 42b is provided near the periphery of the substrate 10 in the short direction (Y direction) of the substrate 10. Part 42b extends in the longitudinal direction (X direction) of the substrate 10 and is electrically connected to one terminal 41 and part 42a1.

[0054] Part 42b1 extends in the longitudinal direction (X direction) of the substrate 10 and is electrically connected to the heating element 30b and part 42a1. The end of the heating element 30b opposite to the side to which part 42b1 is electrically connected is electrically connected to a terminal 41. Terminal 41 and the heating element 30b may be directly connected, or a pattern wiring may be provided between terminal 41 and the heating element 30b.

[0055] Part 42b2 extends in the longitudinal direction (X direction) of the substrate 10 and is electrically connected to the heating element 30a and one terminal 41. The heating element 30 extends in the longitudinal direction (X direction) of the substrate 10 and is electrically connected to one terminal 41 and to part 42a1. Terminal 41 and the heating element 30 may be directly connected, or a pattern wiring may be provided between terminal 41 and the heating element 30. Part 42a1 and the heating element 30 may be directly connected, or a pattern wiring may be provided between part 42a1 and the heating element 30.

[0056] The protective section 50 is, for example, provided on top of the insulating section 20 and covers the heating elements 30, 30a, 30b and the pattern wiring 43 (parts 42a1, 42b, 42b1, and 42b2). In this case, the terminal 41 is exposed from the protective section 50.

[0057] As shown in Figure 6, four detection units 70 are provided on the insulating unit 60. The four detection units 70 are provided at predetermined intervals in the longitudinal direction (X direction) and the short direction (Y direction) of the substrate 10.

[0058] The wiring 85 has four terminals 81 and patterned wiring 82a to 82g. The four terminals 81 and the patterned wiring 82a to 82g can be formed integrally. The material and formation method of the wiring 85 can be the same as, for example, the material and formation method of the wiring 40 described above. The number of terminals 81 and the number of patterned wiring 82a to 82g can be appropriately changed according to the number of detection units 70.

[0059] For example, one terminal 81 can be provided for each detection unit 70. The heater 1a illustrated in Figure 6 has four detection units 70, so four terminals 81 are provided. The four terminals 81 are located near the end of the substrate 10 on the side where the four terminals 41 are located in the longitudinal direction (X direction). The four terminals 81 can be arranged in a line along the short direction (Y direction) of the substrate 10 with a predetermined spacing between them. In other words, in the heater 1a, the four terminals 81 are concentrated near one end of the substrate 10.

[0060] Pattern wiring 82a is provided on the insulating portion 60 and is electrically connected to terminal 81 and detection portion 70. Pattern wiring 82b is provided on the insulating portion 60, and one end of it is electrically connected to the detection portion 70 to which pattern wiring 82a is electrically connected. Pattern wiring 82b extends in the longitudinal direction (X direction) of the substrate 10, and the end opposite to the detection portion 70 side is electrically connected to the substrate 10 outside the insulating portion 60.

[0061] The pattern wiring 82c is provided on the insulating portion 60 and is electrically connected to the terminal 81 and the detection portion 70. The pattern wiring 82d is provided on the insulating portion 60, and one end of it is electrically connected to the detection portion 70 to which the pattern wiring 82c is electrically connected. The pattern wiring 82d extends in the longitudinal direction (X direction) of the substrate 10, and the end opposite to the detection portion 70 is electrically connected to the substrate 10 outside the insulating portion 60.

[0062] The pattern wiring 82e is provided on the insulating portion 60 and is electrically connected to the terminal 81 and the detection portion 70. The pattern wiring 82f is provided on the insulating portion 60, and one end of it is electrically connected to the detection portion 70 to which the pattern wiring 82e is electrically connected. The pattern wiring 82f extends in the longitudinal direction (X direction) of the substrate 10, and the end opposite to the detection portion 70 is electrically connected to the substrate 10 outside the insulating portion 60.

[0063] The pattern wiring 82g is provided on the insulating portion 60 and is electrically connected to the terminal 81 and the detection portion 70. The pattern wiring 82h is provided on the insulating portion 60, and one end of it is electrically connected to the detection portion 70 to which the pattern wiring 82g is electrically connected. The pattern wiring 82h extends in the longitudinal direction (X direction) of the substrate 10, and the end opposite to the detection portion 70 is electrically connected to the substrate 10 outside the insulating portion 60.

[0064] The materials and formation methods for terminal 81 and pattern wiring 82a to 82h can be the same as those for terminal 41 and pattern wiring 42 described above.

[0065] The protective section 90 is provided, for example, on top of the insulating section 60 and covers the detection section 70 and the pattern wiring 82a to 82g. In this case, the terminal 81 is exposed from the protective section 90.

[0066] In heater 1a, the conductive substrate 10 functions as wiring and terminals electrically connected to the detection unit 70 (wirings 82b, 82d, 82f, 82h). For example, as shown in Figure 6, the vicinity of the end of the substrate 10 on the side where terminal 81 is provided functions as terminal 81a electrically connected to the detection unit 70 via wirings 82b, 82d, 82f, 82h.

[0067] As shown in Figure 6, if terminals 41, 81, and 81a are located near the same end of the substrate 10 in the longitudinal direction (X direction), the heater 1a and external equipment can be electrically connected with a single harness. This simplifies harness routing, reduces wiring space, simplifies harness wiring work, and shortens wiring time.

[0068] Furthermore, since the conductive substrate 10 functions as wiring electrically connected to the detection unit 70 (wirings 82b, 82d, 82f, 82h), there is no need to fold the wirings 82b, 82d, 82f, and 82h back towards the terminal 81. As a result, the dimensions of the substrate 10 in the short direction (Y direction) can be reduced, which allows for miniaturization of the heater 1.

[0069] (Image forming apparatus) In one embodiment of the present invention, an image forming apparatus 100 equipped with a heater 1 can be provided. The above-described description of the heater 1 and its variations (e.g., heater 1a) can all be applied to the image forming apparatus 100.

[0070] In the following explanation, we will describe the case where the image forming apparatus 100 is a copier as an example. However, the image forming apparatus 100 is not limited to a copier; it can be any apparatus equipped with a heater for fixing toner. For example, the image forming apparatus 100 can be a printer or a rewritable card reader / writer.

[0071] Figure 7 is a schematic diagram illustrating the image forming apparatus 100 according to this embodiment. Figure 8 is a schematic diagram illustrating the fixing section 200. As shown in Figure 7, the image forming apparatus 100 includes, for example, a frame 110, an illumination unit 120, an imaging element 130, a photosensitive drum 140, a charging unit 150, a discharge unit 151, a developing unit 160, a cleaner 170, a storage unit 180, a transport unit 190, a fixing unit 200, and a controller 210.

[0072] The frame 110 is box-shaped and houses the illumination unit 120, the imaging element 130, the photosensitive drum 140, the charging unit 150, the developing unit 160, the cleaner 170, part of the storage unit 180, the transport unit 190, the fixing unit 200, and the controller 210 inside. A window 111 made of a light-transmitting material such as glass can be provided on the top surface of the frame 110. The original document 500 to be copied is placed on top of the window 111. A movable part for moving the position of the original document 500 can also be provided.

[0073] The lighting unit 120 is provided near the window 111. The lighting unit 120 includes, for example, a light source 121 such as a lamp, and a reflector 122. The imaging element 130 is provided near the window 111. The photosensitive drum 140 is located below the illumination unit 120 and the imaging element 130. The photosensitive drum 140 is rotatably mounted. The surface of the photosensitive drum 140 is provided with, for example, a zinc oxide photosensitive layer or an organic semiconductor photosensitive layer. The charging unit 150, the discharge unit 151, the developing unit 160, and the cleaner 170 are located around the photosensitive drum 140.

[0074] The storage unit 180 includes, for example, a cassette 181 and a tray 182. The cassette 181 is detachably attached to one side of the frame 110. The tray 182 is located on the side of the frame 110 opposite to the side to which the cassette 181 is attached. The cassette 181 holds paper 510 (for example, blank paper) before copying. The tray 182 holds paper 511 on which the copied image 511a has been fixed.

[0075] The transport unit 190 is located below the photosensitive drum 140. The transport unit 190 transports the paper 510 between the cassette 181 and the tray 182. The transport unit 190 includes, for example, a guide 191 that supports the paper 510 being transported, and transport rollers 192 to 194 that transport the paper 510. The transport unit 190 may also be equipped with a motor to rotate the transport rollers 192 to 194.

[0076] The fixing unit 200 is located downstream of the photosensitive drum 140 (on the tray 182 side). As shown in Figure 8, the fixing unit 200 includes, for example, a heater 1, a stay 201, a film belt 202, and a pressure roller 203. A heater 1 is attached to the stay 201 on the side facing the paper 510 transport line. The heater 1 can be embedded in the stay 201. For example, the side of the heater 1 with the protective part 50 can be exposed from the stay 201.

[0077] The film belt 202 covers the stay 201 on which the heater 1 is provided. The film belt 202 can be formed from a heat-resistant resin such as polyimide.

[0078] The pressure roller 203 is positioned opposite the stay 201. The pressure roller 203 includes, for example, a core metal 203a, a drive shaft 203b, and an elastic part 203c. The drive shaft 203b protrudes from the end of the core metal 203a and is connected to a drive device such as a motor. The elastic part 203c is provided on the outer surface of the core metal 203a. The elastic part 203c is formed from a heat-resistant elastic material. The elastic part 203c can be formed from, for example, silicone resin.

[0079] The controller 210 is located inside the frame 110. The controller 210 includes, for example, a processing unit such as a CPU (Central Processing Unit) and a storage unit that stores a control program. The processing unit controls the operation of each element provided in the image forming apparatus 100 based on the control program stored in the storage unit. The controller 210 may also include an operation unit for the user to input copying conditions, a display unit to display the operating status and error indications, etc. Since known techniques can be applied to the control of each element provided in the image forming apparatus 100, a detailed explanation will be omitted.

[0080] Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Furthermore, the embodiments described above can be implemented in combination with each other.

[0081] The following are additional notes regarding the embodiments described above.

[0082] (Note 1) A conductive substrate extending in a first direction; A first insulating portion is provided on the first surface of the substrate, has insulating properties, and extends in the first direction; A heating element provided on the first insulating portion and extending in the first direction; Near one end of the substrate in the first direction, a first terminal is provided on the first insulating portion and is electrically connected to the end of the heating element; The substrate has a second insulating portion provided on a second surface facing the first surface, which is insulating and extends in the first direction; A detection unit is provided on the second insulating portion and is capable of detecting the temperature of the substrate; Near the end of the substrate on the side where the first terminal is provided, a second terminal is provided on the second insulating portion and is electrically connected to the detection portion; A pattern wiring is provided on the second insulating portion, extending in the first direction, with one end electrically connected to the detection portion and the other end electrically connected to the substrate outside the second insulating portion; A heater equipped with [a certain feature].

[0083] (Note 2) Multiple heating elements are provided, The heater according to Appendix 1, wherein the plurality of heating elements are arranged in a second direction perpendicular to the first direction at predetermined intervals.

[0084] (Note 3) Multiple detection units are provided, Each of the plurality of detection units is electrically connected to the pattern wiring of the heater as described in Appendix 1 or 2.

[0085] (Note 4) An image forming apparatus equipped with a heater as described in any one of the appendices 1 to 3. [Explanation of Symbols]

[0086] 1 Heater, 1a Heater, 10 Substrate, 10a side, 10b side, 20 Insulation part, 30 Heating element, 30a Heating element, 30b Heating element, 40 Wiring, 41 Terminal, 42 Pattern wiring, 50 Protection part, 60 Insulation part, 70 Detection part, 80 Wiring, 81 Terminal, 82a~82g Pattern wiring, 83 Wiring, 90 Protection part, 100 Image forming apparatus, 200 Fixing part

Claims

1. A conductive substrate extending in a first direction; A first insulating portion provided on the first surface of the substrate, having insulating properties and extending in the first direction; A heating element provided on the first insulating portion and extending in the first direction; Near one end of the substrate in the first direction, a first terminal is provided on the first insulating portion and is electrically connected to the end of the heating element; A second insulating portion is provided on the second surface of the substrate facing the first surface, has insulating properties, and extends in the first direction; A detection unit provided on the second insulating portion and capable of detecting the temperature of the substrate; Near the end of the substrate on the side where the first terminal is provided, a second terminal is provided on the second insulating portion and is electrically connected to the detection portion; A pattern wiring is provided on the second insulating portion, extending in the first direction, with one end electrically connected to the detection portion and the other end electrically connected to the substrate outside the second insulating portion; A heater equipped with [a certain feature].

2. Multiple heating elements are provided, The heater according to claim 1, wherein the plurality of heating elements are arranged in a second direction perpendicular to the first direction at predetermined intervals.

3. Multiple detection units are provided, The heater according to claim 1 or 2, wherein each of the plurality of detection units is electrically connected to the pattern wiring.

4. An image forming apparatus comprising the heater described in claim 1.

Images