Heater

Abstract

The present disclosure provides a heater that, even when heating is performed at a low temperature with respect to a voltage applied to an electrode, can achieve uniform heating throughout the entire PTC heating element without enlarging the gap between the electrodes, and stably generates heat in a low-temperature region. A heater according to the present invention is provided with a PTC heating element and two sets of comb-shaped electrodes, each of the two sets of comb-shaped electrodes is laminated on the PTC heating element such that the comb-shaped portions of the comb-shaped electrodes in the set face each other and are arranged in a nesting manner, and the two sets of comb-shaped electrodes are connected in series.

Description

heater Technical Field

[0001] This disclosure relates to heaters using PTC heating elements. Background Technology

[0002] Heating elements with PTC (Positive Temperature Coefficient) characteristics are known to be safe heating elements with overheat protection functions, and they are widely used in electric heaters in vehicles, home appliances, industrial equipment, and other fields. PTC heating elements have the characteristic that their resistance increases sharply when the temperature exceeds a specified level, but they suppress the temperature rise through a self-regulating function. Therefore, they can provide stable heating performance and prevent damage caused by overheating.

[0003] As an electrode for energizing a PTC heating element, one type comprises a stack of comb-shaped positive and negative electrodes arranged in a nested configuration with the comb-shaped portions of the positive and negative electrodes facing each other. This comb-shaped electrode is a structure used to efficiently supply current to the PTC heating element and achieve heating throughout the entire heating element. In particular, by making the comb-shaped portions of the electrode in direct contact with the PTC heating element, heating efficiency is improved, and heating can be achieved throughout the entire surface of the heating element.

[0004] Figure 9 is an exploded view of a heater using a conventional PTC heating element. In the heater 100, a set of comb-shaped electrodes 102 and 103 are stacked on the lower surface of a substrate 101. A PTC heating element 104 is stacked below the electrodes 102 and 103, covering the comb-shaped portions of the electrodes 102 and 103. The electrodes 102 and 103 are arranged such that the comb-shaped + electrode 102 and the comb-shaped - electrode 103 face each other. The connection portion 1021 of the + electrode 102 is connected to the + terminal 106 via a wiring ring 108. This + terminal 106 is connected to the + electrode of a power source via wiring (not shown). Similarly, the connection portion 1031 of the - electrode 103 is connected to the - terminal 107 via a wiring ring 109. This - terminal 107 is connected to the - electrode of a power source via wiring (not shown). The + terminal 106 and the - terminal 107 are covered and protected by a sealing material 110. Furthermore, electrodes 102 and 103 and the PTC heating element 104 are covered and protected by double-sided tape 105, and the heater 100 is mounted in the desired position via the double-sided tape 105. Thus, when a voltage is applied between the comb-shaped + electrode 102 and - electrode 103 of the heater 100 located in the desired position, current flows through the PTC heating element 104, thereby generating heat.

[0005] Figure 10 is a bottom view of the heater 100 in Figure 9. A + electrode 102 and a - electrode 103 are stacked on a substrate 101. The + electrode 102 includes a connecting portion 1021, a main body portion 1022 extending from the connecting portion 1021, and a plurality of (three in the figure) comb-like teeth 1023, 1024, and 1025 extending from the main body portion 1022 in a generally orthogonal direction (towards the main body portion 1032 of the - electrode 103). The - electrode 103 includes a connecting portion 1031, a main body portion 1032 extending from the connecting portion 1031, and a plurality of (two in the figure) comb-like teeth 1033 and 1034 extending from the main body portion 1032 in a generally orthogonal direction (towards the main body portion 1022 of the + electrode 102). Furthermore, the comb-like portions 1023, 1024, and 1025 of the + electrode 102 and the comb-like portions 1033 and 1034 of the - electrode 103 are arranged in a nested configuration opposite to each other. Additionally, the PTC heating element 104 is stacked to cover the comb-like portions 1023, 1024, 1025, 1033, and 1034. With this structure, when a voltage is applied between the + electrode 102 and the - electrode 103, current flows from the comb-like portions 1023, 1024, and 1025 of the + electrode 102 towards the comb-like portions 1033 and 1034 of the - electrode 103, passing through the PTC heating element 104 in the vertical direction shown in the figure, thereby heating the PTC heating element 104.

[0006] Prior art literature, patent literature, patent literature 1: Japanese Patent Application Publication No. 59-101790.

[0007] Patent Document 2: Japanese Patent Application Publication No. 2020-042926. Summary of the Invention

[0008] The problem this invention aims to solve is that when attempting to heat an electrode at a lower temperature relative to the voltage applied to the electrode, it is necessary to increase the spacing of the comb teeth. However, if the spacing of the comb teeth is too large, the temperature distribution on the surface of the heating element becomes uneven, resulting in temperature inhomogeneity. This temperature inhomogeneity can degrade the performance of the heater, for example, potentially leading to insufficient heating in low-temperature regions.

[0009] The purpose of this disclosure is to provide a heater that can achieve uniform heating throughout the entire PTC heating element without increasing the electrode spacing, even when heating at a lower temperature relative to the voltage applied to the electrodes, and can also heat stably in the low-temperature region.

[0010] The solution to the problem: The heater disclosed herein includes a PTC heating element and two sets of comb-shaped electrodes. Each set of comb-shaped electrodes is stacked on the PTC heating element in a nested manner with the comb teeth of each set of comb-shaped electrodes facing each other. Furthermore, the two sets of comb-shaped electrodes are connected in series.

[0011] In this disclosure, the comb teeth are arranged in a nested configuration relative to each other, meaning that the comb teeth of another electrode are inserted between the multiple comb teeth of one electrode.

[0012] According to this disclosure, since the two sets of comb-shaped electrodes are connected in series, the voltage applied to each electrode can be reduced. As a result, the PTC heating element can be heated uniformly at a low temperature without increasing the spacing between the electrodes. Attached Figure Description

[0013] Figure 1 is an exploded view of the heater according to the first embodiment.

[0014] Figure 2 is a top view and a bottom view of the heater according to the first embodiment.

[0015] Figure 3 is a top view and a bottom view of the heater according to the second embodiment.

[0016] Figure 4 is a top view and a bottom view of the heater according to the third embodiment.

[0017] Figure 5 is an exploded view of the heater according to the fourth embodiment.

[0018] Figure 6 is a top view and a bottom view of the heater according to the fourth embodiment.

[0019] Figure 7 is an exploded view of the heater according to the fifth embodiment.

[0020] Figure 8 is a top view and a bottom view of the heater according to the fifth embodiment.

[0021] Figure 9 is an exploded view of a conventional heater.

[0022] Figure 10 is a bottom view of a conventional heater.

[0023] Explanation of reference numerals in the attached drawings: 1. Heater; 2. Substrate; 3. +Electrode; 4. -Electrode; 5. PTC heating element; 6. Single-sided tape; 7. +Electrode; 8. -Electrode; 9. PTC heating element; 10. Double-sided tape; 11. +Terminal; 12. -Terminal; 13. Wiring ring; 14. Wiring ring; 15. Wiring ring; 16. Wiring ring; 17. Sealing material; 18. Hole; 21. First heating element unit; 22. Second heating element unit; 31. Connecting part; 32. Main body; 33. Comb tooth part; 41. Connecting part; 42. Main body; 43. Comb tooth part; 71. Connecting part; 72. Main body; 73. Comb tooth part; 81. Connecting part; 82. Main body; 83. Comb tooth part. Detailed Implementation

[0024] Hereinafter, the heater according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. Please note that the drawings are schematic diagrams and not exact illustrations. Furthermore, in the various drawings, substantially identical structures are given the same reference numerals, and repeated descriptions are omitted or simplified as appropriate.

[0025] (First Embodiment) FIG1 is an exploded view of the heater 1 according to the first embodiment of the present disclosure. The heater 1 is constructed by stacking a first heating element unit 21 and a second heating element unit 22 sandwiching a substrate 2. In the first heating element unit 21, electrodes 3 and 4 are disposed on the upper surface of the substrate 2, and a PTC heating element 5 is stacked on the electrodes 3 and 4 in such a way that it covers the comb-like portions of the electrodes 3 and 4. In the electrodes 3 and 4, the comb-like positive electrode 3 and the comb-like negative electrode 4 are arranged in a nested manner with their comb-like portions facing each other, thereby allowing current to flow between the positive electrode 3 and the negative electrode 4 through the PTC heating element 5.

[0026] In the second heating element unit 22, electrodes 7 and 8 are disposed on the lower surface of the substrate 2. A PTC heating element 9 is stacked below the electrodes 7 and 8, covering their comb-like portions. Among the electrodes 7 and 8, the comb-shaped positive electrode 7 and the comb-shaped negative electrode 8 are nested together with their comb-like portions facing each other, thereby allowing current to flow between the positive and negative electrodes via the PTC heating element 9. It should be noted that the terms "upper surface" and "lower surface" of the substrate 2 refer to the vertical direction as shown in FIG. 1, and are independent of the orientation in which the heater 1 is disposed in actual use.

[0027] A + terminal 11 is connected to the + electrode 3 of the first heating element unit 21. Furthermore, a - terminal 12 is connected to the - electrode 8 of the second heating element unit 22. Additionally, the - electrode 4 of the first heating element unit 21 and the + electrode 7 of the second heating element unit 22 are connected via wiring rings 15 and 16. The + terminal 11 is connected to the + electrode of the power supply via wiring (not shown), and the - terminal 12 is connected to the - electrode of the power supply via wiring (not shown). Thus, the + electrode 3 of the first heating element unit 21, the PTC heating element 5, the - electrode 4, the + electrode 7 of the second heating element unit 22, the PTC heating element 9, the - electrode 8, and the power supply are connected in series.

[0028] A single-sided adhesive tape 6, approximately the same size as the substrate 2, is affixed to the upper surface of the first heating element unit 21. The single-sided adhesive tape 6 serves to protect the PTC heating element 5 and the electrodes 3 and 4. Three holes 18 are formed in the single-sided adhesive tape 6, through which the + terminal 11, - terminal 12, and wiring ring 15 are exposed. Furthermore, the + terminal 11, - terminal 12, and wiring ring 15 are covered and protected from above by a sealing material 17.

[0029] A double-sided adhesive tape 10, approximately the same size as the substrate 2, is affixed to the lower surface of the second heating element unit 22. The double-sided adhesive tape 10 serves to protect the PTC heating element 9, the positive electrode 7, the negative electrode 8, and the terminal rings 13, 14, and 16. In addition, the double-sided adhesive tape 10 serves to mount the heater 1 onto designated components, etc.

[0030] Figure 2(A) is a top view of the first heating element unit 21 with electrodes 3, 4 and PTC heating element 5 stacked on substrate 2, and Figure 2(B) is a bottom view of the second heating element unit 22 with electrodes 7, 8 and PTC heating element 9 stacked on substrate 2. The positive electrode 3 of the first heating element unit 21 includes a connecting portion 31, a main body portion 32 extending from the connecting portion 31, and a plurality of comb-like teeth (3 in the figure) extending from the main body portion 32 in a generally orthogonal direction (towards the main body portion 42 of the negative electrode 4). The negative electrode 4 of the first heating element unit 21 includes a connecting portion 41, a main body portion 42 extending from the connecting portion 41, and a plurality of comb-like teeth (2 in the figure) extending from the main body portion 42 in a generally orthogonal direction (towards the main body portion 32 of the positive electrode 3). Furthermore, the comb teeth 33, 34, and 35 of the + electrode 3 and the comb teeth 43 and 44 of the - electrode 4 are nested together opposite each other. With this structure, when a voltage is applied between the + electrode 3 and the - electrode 4, current flows from the comb teeth 33, 34, and 35 of the + electrode 3 toward the comb teeth 43 and 44 of the - electrode 4, and flows in the vertical direction shown in the figure via the PTC heating element 5.

[0031] The positive electrode 7 of the second heating element unit 22 includes a connecting portion 71, a main body portion 72 extending from the connecting portion 71, and a plurality of comb-like portions 73 and 74 (two in the figure) extending from the main body portion 72 in a generally orthogonal direction (towards the main body portion 82 of the negative electrode 8). The negative electrode 8 of the second heating element unit 22 includes a connecting portion 81, a main body portion 82 extending from the connecting portion 81, and a plurality of comb-like portions 83, 84, and 85 (three in the figure) extending from the main body portion 82 in a generally orthogonal direction (towards the main body portion 72 of the positive electrode 7). Furthermore, the comb-like portions 73 and 74 of the positive electrode 7 and the comb-like portions 83, 84, and 85 of the negative electrode 8 are arranged in a nested configuration opposite to each other. With this structure, when a voltage is applied between the + electrode 7 and the - electrode 8, current flows from the comb teeth 73, 74 of the + electrode 7 toward the comb teeth 83, 84, 85 of the - electrode 8, and flows in the vertical direction in the figure via the PTC heating element 9.

[0032] In this embodiment, the positive electrode 3, PTC heating element 5, and negative electrode 4 of the first heating element unit 21, and the positive electrode 7, PTC heating element 9, and negative electrode 8 of the second heating element unit 22 are connected in series with a power supply (not shown). Therefore, a voltage approximately half the power supply voltage is applied between the positive electrode 3 and the negative electrode 4, and between the positive electrode 7 and the negative electrode 8. By connecting the two heating element units in series, the voltage applied to the electrodes is approximately half that of a conventional heater with a single heating element unit. Therefore, compared to conventional heating element units, the spacing between the comb-like portions of the positive and negative electrodes can be made narrower even when connected to a high-voltage power supply. As a result, the PTC heating element can heat the material uniformly at a low temperature even without increasing the electrode spacing.

[0033] (Second Embodiment) FIG3(A) is a top view of the first heating element unit 21 in the heater 1 of the second embodiment of the present disclosure, in which electrodes 3, 4 and PTC heating element 5 are stacked on the substrate 2, and FIG3(B) is a bottom view of the second heating element unit 22 in which electrodes 7, 8 and PTC heating element 9 are stacked on the substrate 2.

[0034] Compared to the first embodiment, the number and position of the comb teeth 73, 74, 83, 84 of the electrodes 7, 8 of the second heating element unit 22, as well as the size of the PTC heating element 9, are different. In the first embodiment, the comb teeth 73, 74, 83, 84, 85 of the electrodes 7, 8 of the second heating element unit 22 are arranged in approximately the same position, overlapping with the comb teeth 33, 34, 35, 43, 44 of the electrodes 3, 4 of the first heating element unit 21 when viewed from above. In the second embodiment, the comb teeth 73, 74, 83, 84 of the electrodes 7, 8 of the second heating element unit 22 are arranged between the comb teeth 33, 34, 35, 43, 44 of the electrodes 3, 4 of the first heating element unit 21 when viewed from above.

[0035] In the first heating element unit 21, the + electrode 3 has three comb teeth 33, 34, and 35, and the - electrode 4 has two comb teeth 43 and 44, forming a total of five comb teeth 33, 34, 35, 43, and 44. In the second heating element unit 22, the + electrode 7 has two comb teeth 73 and 74, and the - electrode 8 has two comb teeth 83 and 84, forming a total of four comb teeth 73, 74, 83, and 84. Furthermore, the four comb teeth 73, 74, 83, and 84 of the second heating element unit 22 are positioned precisely in the center between the five comb teeth 33, 34, 35, 43, and 44 of the first heating element unit 21.

[0036] Generally, when current flows to the PTC heating element through comb-shaped electrodes, there is a tendency for the temperature at locations farther from the electrodes to be slightly higher than at locations closer to the electrodes. In other words, there is a tendency for the temperature near the center between the two comb-shaped sections to be higher than the temperature near the comb-shaped sections themselves. In this embodiment, when viewed from above, the lower-temperature portion (comb-shaped section) of the second heating element unit 22 is located at the higher-temperature portion (near the center between the two comb-shaped sections) of the first heating element unit 21, while the higher-temperature portion (near the center between the two comb-shaped sections) of the second heating element unit 22 is located at the lower-temperature portion (comb-shaped section) of the first heating element unit 21. Therefore, the lower-temperature portion of one heating element is heated by the higher-temperature portion of another heating element unit, resulting in temperature uniformity for the entire heater and reducing the number of both higher and lower-temperature portions (temperature unevenness).

[0037] Furthermore, PTC heating elements have the characteristic of higher resistance in areas with higher temperatures and lower resistance in areas with lower temperatures. By reducing temperature unevenness, the resistance of the PTC heating element is made more uniform, resulting in uniform heating throughout the entire PTC heating element.

[0038] (Third Embodiment) FIG4(A) is a top view of the first heating element unit 21 in the heater 1 of the third embodiment of the present disclosure, in which electrodes 3, 4 and PTC heating element 5 are stacked on the substrate 2, and FIG4(B) is a bottom view of the second heating element unit 22 in which electrodes 7, 8 and PTC heating element 9 are stacked on the substrate 2.

[0039] Compared to the first and second embodiments, the number of comb-like portions 73, 74, 75, 83, 84, 85, and 86 of the electrodes 7 and 8 of the second heating element unit 22 increases while the spacing between them decreases. In the first embodiment, when viewed from above, the comb-like portions 73, 74, 83, and 84 of the electrodes 7 and 8 of the second heating element unit 22 are positioned at approximately the same locations as the comb-like portions 33, 34, 35, 43, and 44 of the electrodes 3 and 4 of the first heating element unit 21. In the third embodiment, the number of comb-like portions 73, 74, 75, 83, 84, 85, and 86 of the electrodes 7 and 8 of the second heating element unit 22 increases while the spacing between them decreases.

[0040] In the first heating element unit 21, the + electrode 3 has three comb teeth 33, 34, and 35, and the - electrode 4 has two comb teeth 43 and 44, forming a total of five comb teeth 33, 34, 35, 43, and 44. In the second heating element unit 22, the + electrode 7 has three comb teeth 73, 74, and 75, and the - electrode 8 has four comb teeth 83, 84, 85, and 86, forming a total of seven comb teeth 73, 74, 75, 83, 84, 85, and 86. Furthermore, when viewed from above, some of the seven comb teeth 73, 74, 75, 83, 84, 85, and 86 in the second heating element unit 22 are located in approximately the same position as the five comb teeth 33, 34, 35, 43, and 44 in the first heating element unit 21, while others are located in different positions.

[0041] According to this third embodiment, when viewed from above, the portions of the first heating element unit 21 with higher and lower temperatures are different from those of the second heating element unit 22. Therefore, as a whole, the heater 1 achieves temperature uniformity, resulting in fewer portions with higher and lower temperatures (temperature unevenness).

[0042] Furthermore, by reducing temperature unevenness, the resistance value of the PTC heating element is made more uniform, thus enabling the PTC heating element to heat up evenly as a whole.

[0043] (Fourth Embodiment) Figure 5 is an exploded view of the heater according to the fourth embodiment of this disclosure. Compared with the first embodiment, the orientation of the comb teeth of the electrodes 3 and 4 of the first heating element unit 21 and the electrodes 7 and 8 of the second heating element unit 22 is different. That is, in the fourth embodiment, the comb teeth of the first heating element unit 21 and the comb teeth of the second heating element unit are respectively arranged obliquely so that their orientations are approximately orthogonal.

[0044] Figure 6(A) is a top view of the first heating element unit 21 in the heater 1 of the fourth embodiment of this disclosure, in which electrodes 3, 4 and PTC heating element 5 are stacked on the substrate 2. Figure 6(B) is a bottom view of the second heating element unit 22 in which electrodes 7, 8 and PTC heating element 9 are stacked on the substrate 2. In the top view, the comb-tooth portions 33, 34, and 35 of the + electrode 3 of the first heating element unit 21 extend diagonally downward to the right at a 45-degree angle from the main body portion 32 toward the main body portion 42 of the - electrode 4. Furthermore, in the top view, the comb-tooth portions 43, 44, and 45 of the - electrode 4 extend diagonally upward to the left at a 45-degree angle from the main body portion 42 toward the main body portion 32 of the + electrode 3. Moreover, the comb-tooth portions 33, 34, and 35 of the + electrode 3 and the comb-tooth portions 43, 44, and 45 of the - electrode 4 are arranged in a nested configuration opposite to each other. With this structure, when a voltage is applied between the + electrode 3 and the - electrode 4, current flows from the comb teeth 33, 34, 35 of the + electrode 3 toward the comb teeth 43, 44, 45 of the - electrode 4, and via the PTC heating element 5 in the direction between the right-upward and left-downward directions in the figure.

[0045] When viewed from below, the comb-like portions 73, 74, and 75 of the + electrode 7 of the second heating element unit 22 extend diagonally downward to the right at a 45-degree angle from the main body 72 toward the main body 82 of the - electrode 8. Furthermore, when viewed from below, the comb-like portions 83, 84, 85, and 86 of the - electrode 8 extend diagonally upward to the left at a 45-degree angle from the main body 82 toward the main body 72 of the + electrode 7. The comb-like portions 73, 74, and 75 of the + electrode 7 and the comb-like portions 83, 84, 85, and 86 of the - electrode 8 are arranged in a nested configuration opposite to each other. With this structure, when a voltage is applied between the + electrode 7 and the - electrode 8, current flows from the comb-like portions 73, 74, and 75 of the + electrode 7 toward the comb-like portions 83, 84, 85, and 86 of the - electrode 8, via the PTC heating element 9, in a direction between diagonally upward to the right and diagonally downward to the left in the figure.

[0046] According to this fourth embodiment, when viewed from above, the portions of the first heating element unit 21 with higher and lower temperatures are different from those of the second heating element unit 22. Therefore, as a whole, the heater 1 achieves temperature uniformity, resulting in fewer portions with higher and lower temperatures (temperature unevenness).

[0047] Furthermore, by reducing temperature unevenness, the resistance value of the PTC heating element is made more uniform, thus enabling the PTC heating element to heat up evenly as a whole.

[0048] (Fifth Embodiment) FIG7 is an exploded view of the heater according to the fifth embodiment of the present disclosure. Compared with the first embodiment, the orientation of the comb teeth of the electrodes 7 and 8 of the second heating element unit 22 is different. That is, in the fifth embodiment, the comb teeth of the first heating element unit 21 are arranged in a transverse direction, while the comb teeth of the second heating element unit are arranged in a longitudinal direction, so that the orientation of their comb teeth is approximately orthogonal.

[0049] Figure 8(A) is a top view of the first heating element unit 21 in the heater 1 of the fifth embodiment of this disclosure, in which electrodes 3, 4 and PTC heating element 5 are stacked on the substrate 2. Figure 8(B) is a bottom view of the second heating element unit 22 in which electrodes 7, 8 and PTC heating element 9 are stacked on the substrate 2. In the top view, the comb-tooth portions 33, 34, and 35 of the + electrode 3 of the first heating element unit 21 extend laterally from the main body portion 32 toward the main body portion 42 of the - electrode 4. Furthermore, in the top view, the comb-tooth portions 43 and 44 of the - electrode 4 extend laterally from the main body portion 42 toward the main body portion 32 of the + electrode 3. Moreover, the comb-tooth portions 33, 34, and 35 of the + electrode 3 and the comb-tooth portions 43 and 44 of the - electrode 4 are arranged in a nested configuration opposite to each other. With this structure, when a voltage is applied between the + electrode 3 and the - electrode 4, current flows from the comb teeth 33, 34, 35 of the + electrode 3 toward the comb teeth 43, 44 of the - electrode 4, and then through the PTC heating element 5 in the vertical direction shown in the figure.

[0050] When viewed from below, the comb-like portions 73 and 74 of the + electrode 7 of the second heating element unit 22 extend downwards from the main body 72 toward the main body 82 of the - electrode 8. Furthermore, when viewed from below, the comb-like portions 83 and 84 of the - electrode 8 extend upwards from the main body 82 toward the main body 72 of the + electrode 7. The comb-like portions 73 and 74 of the + electrode 7 and the comb-like portions 83 and 84 of the - electrode 8 are arranged in a nested configuration opposite to each other. With this structure, when a voltage is applied between the + electrode 7 and the - electrode 8, current flows from the comb-like portions 73 and 74 of the + electrode 7 toward the comb-like portions 83 and 84 of the - electrode 8, via the PTC heating element 9, in the transverse direction shown in the figure.

[0051] According to this fifth embodiment, the portions of the first heating element unit 21 that are too hot and too cold are different from the portions of the second heating element unit 22 that are too hot and too cold. Therefore, as a whole, the heater 1 achieves temperature uniformity, resulting in fewer portions of too hot and too cold (temperature unevenness).

[0052] Furthermore, by reducing temperature unevenness, the resistance value of the PTC heating element is made more uniform, thus enabling the PTC heating element to heat up evenly as a whole.

[0053] The present disclosure has been described above according to embodiments, but the present disclosure is not limited to the above embodiments. The number, spacing, and orientation of the comb teeth of each electrode are not limited to the above embodiments. Furthermore, the shape of the heater is not limited to a rectangle, and can be appropriately designed according to the object being heated.

[0054] Industrial applicability: According to the present invention, uniform heating can be achieved even when heating is performed at low temperatures, regardless of the voltage applied to the electrodes.

Claims

1. A heater, characterized in that, It has a PTC heating element and two sets of comb-shaped electrodes. The comb-shaped electrodes in the two sets are stacked on the PTC heating element in a nested manner with the comb teeth of each comb-shaped electrode in the set facing each other. The two sets of comb-shaped electrodes are connected in series.

2. A heater, characterized in that, In this heater, two heating element units, each having a PTC heating element and a comb-shaped electrode, are stacked together. The comb-shaped electrode is stacked on the PTC heating element in a nested manner with the comb teeth facing each other, and the comb-shaped electrodes of the two heating element units are connected in series.

3. The heater as claimed in claim 2, wherein, When viewed from the overlapping direction of the two heating element units, the comb teeth of the comb-shaped electrodes of the two heating element units are arranged at different positions.

4. The heater as claimed in claim 2, wherein, When viewed from the overlapping direction of the two heating element units, the pitch of the comb teeth of the comb-shaped electrodes of the two heating element units is different from that of each other.

5. The heater as claimed in claim 2, wherein, When viewed from the overlapping direction of the two heating element units, the extension directions of the comb teeth of the comb-shaped electrodes of the two heating element units are different from each other.

6. The heater as claimed in claim 5, wherein, The comb-shaped electrodes of the two heating element units extend in directions that are approximately orthogonal to each other.

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