JP7489614B2 - Resistor substrate and variable resistor including same - Google Patents

Description

The present disclosure relates to a resistance substrate and a variable resistor including the same, and more specifically to a resistance substrate including a resistive portion formed on a substrate, and a variable resistor including the resistance substrate.

Patent document 1 describes a resistance substrate that includes a substrate, an arc-shaped first resistor (resistance portion) formed on the substrate, a circular conductor (conductive portion) formed on the substrate and positioned inside the first resistor, and a second resistor (fixed resistance portion) formed on the substrate.

Patent Document 1 also describes a variable resistor that includes a resistance substrate, a first terminal, a second terminal, a third terminal, and a conductive slider. In the variable resistor, both ends of the first resistor are connected to the first terminal and the third terminal, respectively. The second resistor connects the conductor and the second terminal. The slider is disposed in a position that shorts between the first resistor and the conductor, and slides on the first resistor and the conductor.

The variable resistor guarantees the resistance value of the second resistor even if the resistance value of the first resistor is shorted to zero.

Japanese Utility Model Application Publication No. 63-55403

In the resistor substrate disclosed in Patent Document 1, it was difficult to increase the resistance value of the fixed resistor section without increasing the size of the substrate.

The objective of this disclosure is to provide a resistor board and a variable resistor that can increase the resistance value of the fixed resistor section.

A resistance substrate according to an aspect of the present disclosure includes a substrate, a resistance portion, a conductive portion, a first terminal portion, a second terminal portion, a third terminal portion, and a fixed resistance portion. The substrate has electrical insulation. The resistance portion is formed on the substrate. The resistance portion is arc-shaped and has a first end and a second end. The conductive portion is formed on the substrate and is located inside the resistance portion. The conductive portion is arc-shaped and has a first end and a second end. The first terminal portion is formed on the substrate. The first terminal portion is connected to a portion of the first end and the second end in the resistance portion that is closer to the first end. The second terminal portion is formed on the substrate and connected to the conductive portion. The third terminal portion is formed on the substrate. The third terminal portion is connected to a portion of the first end and the second end in the resistance portion that is closer to the second end. The fixed resistance portion is formed on the substrate and connects the conductive portion and the second terminal portion. The resistance value of the fixed resistance portion is greater than the resistance value of the conductive portion. The fixed resistance portion is in contact with the first end of the conductive portion. The conductive portion has an outer edge facing the resistance portion and an inner edge located opposite the outer edge. The fixed resistance portion has an extension portion. The extension portion is located between the first end and the second end of the conductive portion when viewed in the thickness direction of the substrate, and extends toward the first end of the conductive portion. The width of the extension portion is narrower than the width of the conductive portion. The distance between the extension portion and the inner edge of the conductive portion is shorter than the distance between the extension portion and the outer edge of the conductive portion.

A resistance substrate according to an aspect of the present disclosure includes a substrate, a resistance portion, a conductive portion, a first terminal portion, a second terminal portion, a third terminal portion, and a fixed resistance portion. The substrate has electrical insulation. The resistance portion is formed on the substrate. The resistance portion is arc-shaped and has a first end and a second end. The conductive portion is formed on the substrate and is located inside the resistance portion. The conductive portion is arc-shaped and has a first end and a second end. The first terminal portion is formed on the substrate. The first terminal portion is connected to a portion of the first end and the second end in the resistance portion that is closer to the first end. The second terminal portion is formed on the substrate and connected to the conductive portion. The third terminal portion is formed on the substrate. The third terminal portion is connected to a portion of the first end and the second end in the resistance portion that is closer to the second end. The fixed resistance portion is formed on the substrate and connects the conductive portion and the second terminal portion. The resistance value of the fixed resistance portion is greater than the resistance value of the conductive portion. The conductive portion has an outer edge facing the resistor portion and an inner edge located opposite the outer edge, and the fixed resistor portion is in contact with the inner edge of the conductive portion without contacting the first end or the second end of the conductive portion .

A resistance substrate according to one aspect of the present disclosure includes a substrate, a resistance portion, a conductive portion, a first terminal portion, a second terminal portion, a third terminal portion, and a fixed resistance portion. The substrate has electrical insulation. The resistance portion is formed on the substrate. The resistance portion is arc-shaped and has a first end and a second end. The conductive portion is formed on the substrate and is located inside the resistance portion. The conductive portion is annular. The first terminal portion is formed on the substrate. The first terminal portion is connected to a portion of the first end and the second end in the resistance portion that is closer to the first end. The second terminal portion is formed on the substrate and connected to the conductive portion. The third terminal portion is formed on the substrate. The third terminal portion is connected to a portion of the first end and the second end in the resistance portion that is closer to the second end. The fixed resistance portion is formed on the substrate and connects the conductive portion and the second terminal portion. The resistance value of the fixed resistance portion is greater than the resistance value of the conductive portion. The conductive portion has an outer edge facing the resistance portion and a recess provided on the outer edge. The recess includes a first surface, a second surface, and a third surface. The first surface and the second surface intersect in a direction along the outer periphery of the conductive portion and are separated from each other in the direction along the outer periphery of the conductive portion. The third surface connects the first surface and the second surface in a direction along the outer periphery of the conductive portion. The fixed resistance portion is in contact with a portion of the third surface of the recess of the conductive portion that is separated from the first surface and the second surface.

A variable resistor according to one aspect of the present disclosure includes a resistance substrate according to any one of the above aspects and a brush. The brush is conductive. The brush slides on the upper surface of the resistance portion and the upper surface of the conductive portion.

The resistance substrate and variable resistor disclosed herein make it possible to increase the resistance value of the fixed resistance section.

FIG. 1 is a plan view of a resistance substrate according to a first embodiment. FIG. 2 is a plan view of a variable resistor including a resistance substrate according to the first embodiment. FIG. 3 is a plan view of a variable resistor according to a first modification of the first embodiment. FIG. 4 is a plan view of a resistance substrate according to the second embodiment. FIG. 5 is a plan view of a resistance substrate according to the third embodiment.

Embodiments of a resistance substrate and a variable resistor including the same according to the present disclosure will be described below with reference to the drawings. Note that all of the embodiments disclosed below are merely examples, and are not intended to impose limitations on the resistance substrate and variable resistor according to the present disclosure.

In addition, in the embodiments disclosed below, detailed explanations that are more detailed than necessary may be omitted. For example, detailed explanations of matters that are already well known or duplicate explanations of substantially identical configurations may be omitted. This is to avoid unnecessarily redundant explanations and to facilitate understanding by those skilled in the art.

(Embodiment 1)
Hereinafter, a resistance substrate 1 according to a first embodiment and a variable resistor 300 including the same will be described with reference to FIGS. 1 and 2. FIG.

(1) Overview The resistance substrate 1 is used in a variable resistor 300 (see FIG. 2) that includes a brush 10 (see FIG. 2). The variable resistor 300 changes its resistance value depending on the position of the brush 10 when a rotating body that rotates the brush 10 is rotated. In FIG. 2, the brush 10 before the rotating body is rotated is shown by a solid line, and the brush 10 after the rotating body is rotated by an arbitrary angle (e.g., 120 degrees) in a predetermined rotation direction R1 is shown by a dashed dotted line.

The resistance substrate 1 includes a substrate 2, a resistance portion 3, a conductive portion 4, a first terminal portion 6, a second terminal portion 7, a third terminal portion 8, and a fixed resistance portion 5. The substrate 2 has electrical insulation. The resistance portion 3 is formed on the substrate 2. The resistance portion 3 is arc-shaped and has a first end and a second end 32. The conductive portion 4 is formed on the substrate 2 and is located inside the resistance portion 3. The conductive portion 4 is arc-shaped and has a first end 41 and a second end 42. The first terminal portion 6 is formed on the substrate 2. The first terminal portion 6 is connected to a portion of the first end 31 and the second end 32 in the resistance portion 3 that is closer to the first end 31. The second terminal portion 7 is formed on the substrate 2 and connected to the conductive portion 4. The third terminal portion 8 is formed on the substrate 2. The third terminal portion 8 is connected to a portion of the first end 31 and the second end 32 in the resistance portion 3 that is closer to the second end 32. The fixed resistance portion 5 is formed on the substrate 2. The fixed resistance portion 5 connects the conductive portion 4 and the second terminal portion 7. The resistance value of the fixed resistance portion 5 is greater than the resistance value of the conductive portion 4. The fixed resistance portion 5 is in contact with the first end 41 of the conductive portion 4.

The resistance board 1 according to the first embodiment makes it possible to increase the resistance value of the fixed resistance section 5. In the resistance board 1 according to the first embodiment, a part of the fixed resistance section 5 can be disposed between the first end 41 and the second end 42 of the conductive section 4 on the substrate 2. This makes it possible to increase the area on the substrate 2 in which the fixed resistance section 5 can be disposed without increasing the size of the substrate 2. This also makes it possible to increase the length of the fixed resistance section 5, making it possible to increase the resistance value of the fixed resistance section 5.

The variable resistor 300 according to the first embodiment includes a resistance substrate 1 and a brush 10. The brush 10 is conductive. The brush 10 slides on the upper surface 3U of the resistance portion 3 and the upper surface 4U of the conductive portion 4.

The variable resistor 300 according to the first embodiment includes a resistance substrate 1, which makes it possible to increase the resistance value of the fixed resistance section 5.

Although each of FIG. 1 and FIG. 2 is a plan view, the resistive portion 3 and the fixed resistive portion 5 are hatched to make it easier to distinguish between the upper surface 21 of the substrate 2, the resistive portion 3, the conductive portion 4, and the fixed resistive portion 5.

(2) Details (2.1) Resistance Substrate As described above, the resistance substrate 1 includes the substrate 2, the resistance portion 3, the conductive portion 4, the first terminal portion 6, the second terminal portion 7, the third terminal portion 8, and the fixed resistance portion 5.

The substrate 2 is electrically insulating. Materials for the substrate 2 include, for example, phenolic resin, glass epoxy resin, or polyimide.

The substrate 2 has a through hole 211 formed along the thickness direction of the substrate 2. When viewed from the thickness direction of the substrate 2, the opening shape of the through hole 211 is circular. In the variable resistor 300, the shaft portion of the above-mentioned rotating body is inserted into the through hole 211 of the substrate 2. The rotating body has a flange that protrudes outward from the shaft portion. In the variable resistor 300, the brush 10, which is placed on the surface of the rotating body flange that faces the resistance substrate 1, is held by the flange.

When viewed in the thickness direction of the substrate 2, the substrate 2 has a first region 201 in which the resistive portion 3 and the conductive portion 4 are formed, and a second region 202 in which the first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 are formed. The first region 201 is a region having a substantially circular shape. The second region 202 is a region having a substantially rectangular shape. When viewed in the thickness direction of the substrate 2, the outer periphery 200 of the substrate 2 includes a part of the outer periphery of the first region 201 and a part of the outer periphery of the second region 202.

As described above, the resistor portion 3 is formed on the substrate 2. More specifically, the resistor portion 3 is formed on the upper surface 21 of the substrate 2 in the first region 201 of the substrate 2.

The resistor portion 3 contains, for example, carbon black and a resin (for example, a phenolic resin). The resistor portion 3 is formed, for example, by a screen printing method. The resistor portion 3 may have a single-layer structure or a laminated structure of multiple resistor layers. Each of the multiple resistor layers contains, for example, carbon black and a resin. The resistor portion 3 is formed, for example, by a screen printing method.

The resistor portion 3 is arc-shaped when viewed from the thickness direction of the substrate 2. The resistor portion 3 has a first end 31 and a second end 32. The resistor portion 3 also has an inner edge 34 on the through hole 211 side of the substrate 2 when viewed from the thickness direction of the substrate 2, and an outer edge 33 located on the opposite side to the inner edge 34. In the resistor substrate 1 according to the first embodiment, the central angle of the arc-shaped resistor portion 3 is approximately 340 degrees. The central angle of the arc-shaped resistor portion 3 is the angle between a first straight line connecting the center A1 of a circle including the inner edge 34 of the resistor portion 3 and the first end 31 of the resistor portion 3, and a second straight line connecting the center A1 and the second end 32 of the resistor portion 3. The center A1 is at the same position as the center of curvature of the inner edge 34 of the resistor portion 3. The radius of curvature of the inner edge 34 of the resistor portion 3 is larger than the radius of the circular through hole 211. When viewed from the thickness direction of the substrate 2, the center A1 of the circle including the inner edge 34 of the resistor portion 3 is approximately coincident with the center of the through hole 211. The resistor portion 3 is disposed so as to surround the through hole 211 over approximately the entire circumference. In the following description, the point farthest from the first end 31 among the portions of the outer edge 33 of the resistor portion 3 that are in contact with the wiring portion 16 described later is defined as a first point B1, and the point farthest from the second end 32 among the portions of the outer edge 33 of the resistor portion 3 that are in contact with the wiring portion 18 described later is defined as a second point B2. In the variable resistor 300 including the resistance substrate 1, when viewed from the thickness direction of the substrate 2, the resistance value between the first terminal portion 6 and the second terminal portion 7 is minimum when the contact piece 101 of the brush 10 is in contact with the upper surface 3U of the resistor portion 3 on a straight line connecting the center A1 and the first point B1. In addition, in the variable resistor 300 equipped with the resistance substrate 1, when viewed in the thickness direction of the substrate 2, the resistance value between the first terminal portion 6 and the second terminal portion 7 is maximum when the contact piece 101 of the brush 10 is in contact with the upper surface 3U of the resistance portion 3 on a straight line connecting the center A1 and the second point B2.

As described above, the conductive portion 4 is formed on the substrate 2. More specifically, the conductive portion 4 is formed on the upper surface 21 of the substrate 2 in the first region 201 of the substrate 2 and is located inside the resistor portion 3.

The conductive part 4 has, for example, a laminated structure of multiple conductive layers. The conductivity of the bottom conductive layer (hereinafter referred to as the first conductive layer) that is closest to the substrate 2 among the multiple conductive layers is greater than the conductivity of the top conductive layer (hereinafter referred to as the second conductive layer) that is farthest from the substrate 2. The hardness of the second conductive layer is greater than the hardness of the first conductive layer. The first conductive layer contains, for example, silver particles and a resin. The second conductive layer contains, for example, carbon black and a resin. In the conductive part 4, the multiple conductive layers only need to have at least the first conductive layer and the second conductive layer, and may have a conductive layer interposed between the first conductive layer and the second conductive layer. The conductive part 4 is formed, for example, by a screen printing method. The conductive part 4 is not limited to having a laminated structure of multiple conductive layers, and may have a single-layer structure.

The conductive portion 4 is arc-shaped when viewed from the thickness direction of the substrate 2. The conductive portion 4 has a first end 41 and a second end 42. When viewed from the thickness direction of the substrate 2, the conductive portion 4 is located between the resistance portion 3 and the through hole 211 and away from the resistance portion 3 and the through hole 211. The conductive portion 4 has an outer edge 43 facing the resistance portion 3 and an inner edge 44 located on the opposite side to the outer edge 43. In the resistance substrate 1 according to the first embodiment, the central angle of the arc-shaped conductive portion 4 is approximately 340 degrees. The central angle of the arc-shaped conductive portion 4 is the angle between a straight line connecting the center of a circle including the inner edge 44 of the conductive portion 4 and the first end 41 of the conductive portion 4, and a straight line connecting the center and the second end 42 of the conductive portion 4. The radius of curvature of the inner edge 44 of the conductive portion 4 is larger than the radius of the circular through hole 211, but is not limited to this and may be the same as the radius of the through hole 211. When viewed in the thickness direction of the substrate 2, the center of the circle including the inner edge 44 of the conductive portion 4 approximately coincides with the center of the through hole 211. The conductive portion 4 is disposed so as to surround the through hole 211 over approximately the entire circumference.

As described above, the first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 are formed on the substrate 2. More specifically, the first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 are formed on the upper surface 21 of the substrate 2 in the second region 202 of the substrate 2.

When viewed in the thickness direction of the substrate 2, each of the first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 is rectangular. Each of the first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 is not limited to a rectangular shape and may be, for example, a circular shape.

When viewed from the thickness direction of the substrate 2, the first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 are arranged in the order of the first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 in the direction along which the first end 31 and the second end 32 of the resistor portion 3 are arranged (hereinafter also referred to as the first direction). In the resistor substrate 1 according to the first embodiment, when viewed from the thickness direction of the substrate 2, the space between the first end 31 and the second end 32 of the resistor portion 3, the space between the first end 41 and the second end 42 of the conductive portion 4, and the fixed resistor portion 5 are located in an area obtained by projecting the second terminal portion 7 in a second direction (upward in FIG. 1) perpendicular to the first direction (rightward in FIG. 1).

Each of the first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 contains, for example, silver particles and resin. The first terminal portion 6, the second terminal portion 7, and the third terminal portion 8 are formed, for example, by a screen printing method.

The resistance substrate 1 further includes a wiring portion 16 and a wiring portion 18 formed on the substrate 2. The wiring portion 16 and the wiring portion 18 are formed on the upper surface 21 of the substrate 2. The wiring portion 16 connects a part of the outer peripheral edge of the first terminal portion 6 to a part of the outer edge 33 of the resistance portion 3 near the first end 31. The wiring portion 18 connects a part of the outer peripheral edge of the third terminal portion 8 to a part of the outer edge 33 of the resistance portion 3 near the second end 32.

Each of the wiring portion 16 and the wiring portion 18 contains, for example, silver particles and resin. The wiring portion 16 and the wiring portion 18 are formed, for example, by a screen printing method.

The fixed resistance portion 5 is formed on the substrate 2 as described above. The fixed resistance portion 5 connects the conductive portion 4 and the second terminal portion 7. More specifically, the fixed resistance portion 5 connects a part of the outer periphery of the second terminal portion 7 and the conductive portion 4. The fixed resistance portion 5 is formed on the upper surface 21 of the substrate 2 across the first region 201 and the second region 202 of the substrate 2. The resistance value of the fixed resistance portion 5 is greater than the resistance value of the conductive portion 4.

The fixed resistor section 5 contains, for example, carbon black and a resin (for example, a phenolic resin). The fixed resistor section 5 is formed, for example, by a screen printing method. The fixed resistor section 5 may have a single-layer structure or a laminated structure of multiple resistor layers. Each of the multiple resistor layers contains, for example, carbon black and a resin. The resistor section 3 is formed, for example, by a screen printing method.

The fixed resistance portion 5 is in contact with the first end 41 of the conductive portion 4. More specifically, the fixed resistance portion 5 is in contact with the first end 41 of the conductive portion 4 without being in contact with the outer edge 43 of the conductive portion 4. The fixed resistance portion 5 is also in contact with the second end 42 of the conductive portion 4. More specifically, the fixed resistance portion 5 is in contact with the second end 42 of the conductive portion 4 without being in contact with the outer edge 43 of the conductive portion 4.

The fixed resistor section 5 has an extension section 51. When viewed from the thickness direction of the substrate 2, the extension section 51 is located between the first end 41 and the second end 42 of the conductive section 4. The extension section 51 extends toward the first end 41 of the conductive section 4. The width of the extension section 51 is narrower than the width of the conductive section 4. The distance between the extension section 51 and the inner edge 44 of the conductive section 4 is shorter than the distance between the extension section 51 and the outer edge 43 of the conductive section 4. In other words, when viewed from the thickness direction of the substrate 2, the extension section 51 is located inside a circle that includes the outer edge 43 of the conductive section 4.

When viewed from the thickness direction of the substrate 2, the fixed resistor 5 has a main body 5A connected to the second terminal 7 and located outside the circle including the outer edge 43 of the conductive portion 4, and an extension 50 extending from the main body 5A through the space between the first end 41 and the second end 42 of the conductive portion 4 to the circle including the inner edge 44 of the conductive portion 4. The main body 5A is linear. The width of the main body 5A is shorter than the distance between the first end 31 and the second end 32 of the resistor 3. When viewed from the thickness direction of the substrate 2, a part of the main body 5A is located between the first end 31 and the second end 32 of the resistor 3 and away from the first end 31 and the second end 32. The width of the main body 5A is shorter than the distance between the first end 41 and the second end 42 of the conductive portion 4. The extension 50 is linear. The width of the extension 50 is shorter than the distance between the first end 41 and the second end 42 of the conductive portion 4. When viewed in the thickness direction of the substrate 2, the extension portion 50 is located between the first end 41 and the second end 42 of the conductive portion 4 and away from the first end 41 and the second end 42. The extension portion 51 described above extends from the tip of the extension portion 50 toward the first end 41 of the conductive portion 4.

The extension portion 51 is arc-shaped. The radius of curvature of the inner edge of the extension portion 51 on the through hole 211 side is, for example, the same as the radius of curvature of the inner edge 44 of the conductive portion 4.

In the resistance substrate 1 according to the first embodiment, the fixed resistance portion 5 further includes a second extension portion 52 in addition to the first extension portion 51, which is the extension portion 51. The second extension portion 52 is located between the first end 41 and the second end 42 of the conductive portion 4 when viewed from the thickness direction of the substrate 2. The second extension portion 52 extends toward the second end 42 of the conductive portion 4. The width of the second extension portion 52 is narrower than the width of the conductive portion 4. In the width direction of the conductive portion 4, the distance between the second extension portion 52 and the inner edge 44 of the conductive portion 4 is shorter than the distance between the second extension portion 52 and the outer edge 43 of the conductive portion 4. In other words, the second extension portion 52 is located inside a circle including the outer edge 43 of the conductive portion 4 when viewed from the thickness direction of the substrate 2. The second extension portion 52 extends from the tip of the extension portion 50 toward the second end 42 of the conductive portion 4.

The second extension portion 52 is arc-shaped. The radius of curvature of the inner edge of the second extension portion 52 on the through hole 211 side is, for example, the same as the radius of curvature of the inner edge 44 of the conductive portion 4.

(2.2) Variable Resistor The variable resistor 300 includes a resistance substrate 1 and a brush 10. The variable resistor 300 further includes a rotor that rotates the brush 10. In the variable resistor 300, when the rotor is rotated, the brush 10 slides on the upper surface 3U of the resistance portion 3 and the upper surface 4U of the conductive portion 4.

The rotating body has electrical insulation. The rotating body is, for example, a resin molded product. As described above, the rotating body has a shaft portion that is inserted into the through hole 211 of the substrate 2, and a flange that protrudes outward from the shaft portion. The shaft portion is cylindrical, but is not limited to this, and may be, for example, a bottomed cylindrical shape or a columnar shape. The outer peripheral shape of the flange is circular. The outer diameter of the flange is larger than the radius of curvature of the outer edge 33 of the resistance portion 3. The flange is separated from the resistance portion 3 and the conductive portion 4 in the thickness direction of the substrate 2.

The brush 10 is formed of a conductive plate (e.g., a metal plate). The brush 10 has a fixed part 100 that is disposed on the underside of the flange of the rotating body and fixed to the flange, and two first contact pieces 101 and two second contact pieces 102 that protrude from the fixed part 100 in a direction along the circumferential direction of the flange and are elastically deformable in the thickness direction of the flange. The fixed part 100 has a plurality of (three) holes 103 through which a plurality of (three) positioning protrusions protruding from the flange pass. In the variable resistor 300, the flange holds the brush by crimping the tip of each of the plurality of positioning protrusions. In the brush 10, the fixed part 100 is located away from the resistance substrate 1 in the thickness direction of the substrate 2. In the brush 10, the two first contact pieces 101 are in elastic contact with the upper surface 3U of the resistance part 3, and the two second contact pieces 102 are in elastic contact with the upper surface 4U of the conductive part 4.

In the variable resistor 300, when the rotating body is rotated to a desired angle by the user's operation, the brush 10 rotates together with the rotation of the rotating body. At this time, in the brush 10, the two first contact pieces 101 slide on the upper surface 3U of the resistance part 3, and the two second contact pieces 102 slide on the upper surface 4U of the conductive part 4. The resistance value changes depending on the contact position between the brush 10 and the upper surface 3U of the resistance part 3 when the rotating body that rotates the brush 10 is rotated.

In the variable resistor 300, for example, when a DC voltage is applied between the third terminal 8 and the first terminal 6 with the third terminal 8 at a high potential, the voltage between the second terminal 7 and the first terminal 6 changes depending on the contact position between the brush 10 and the upper surface 3U of the resistor 3. In the example of FIG. 2, the voltage between the second terminal 7 and the first terminal 6 when the brush 10 is in the dashed line position (a position where the brush 10 has rotated by an arbitrary angle) is higher than the voltage between the second terminal 7 and the first terminal 6 when the brush 10 is in the solid line position (reference position). Therefore, for example, in an electronic circuit connected to the first terminal 6, the second terminal 7, and the third terminal 8 of the variable resistor 300, information on the rotation angle of the rotor can also be obtained based on the voltage between the second terminal 7 and the first terminal 6.

In addition, since the variable resistor 300 includes a fixed resistor portion 5, it is possible to prevent an overcurrent from flowing in the event of a misconnection, for example, in which a power source that should be electrically connected between the third terminal portion 8 and the first terminal portion 6 is electrically connected between the second terminal portion 7 and the first terminal portion 6.

(3) Advantages (3.1) Resistance Substrate In the resistance substrate 1 according to the first embodiment, the fixed resistance portion 5 is in contact with the first end 41 of the arc-shaped conductive portion 4 having the first end 41 and the second end 42. This allows the resistance substrate 1 according to the first embodiment to have a larger resistance value of the fixed resistance portion 5. More specifically, in the resistance substrate 1 according to the first embodiment, a part of the fixed resistance portion 5 can be disposed between the first end 41 and the second end 42 of the conductive portion 4 on the substrate 2. This allows the resistance substrate 1 according to the first embodiment to have a larger area on the substrate 2 in which the fixed resistance portion 5 can be disposed without increasing the size of the substrate 2, and allows the length of the fixed resistance portion 5 to be longer, compared to a resistance substrate configured such that the fixed resistance portion is connected to the outer periphery of a circular conductive portion, for example. This allows the resistance substrate 1 according to the first embodiment to have a larger resistance value of the fixed resistance portion 5, because the fixed resistance portion 5 can have a larger length.

In addition, in the resistance substrate 1 according to embodiment 1, the length of the fixed resistance portion 5 is long and the resistance value is large, so that the resistance value can be easily changed by changing the width of the fixed resistance portion 5. As a result, in the resistance substrate 1 according to embodiment 1, it is easy to adopt a manufacturing process in which the material composition of the fixed resistance portion 5 and the material composition of the resistance portion 3 are made the same, and the fixed resistance portion 5 and the resistance portion 3 are simultaneously formed by the same screen printing process.

(3.2) Variable Resistor The variable resistor 300 according to the first embodiment includes a resistance substrate 1 and a brush 10. The brush 10 is conductive. The brush 10 slides on an upper surface 3U of the resistance portion 3 and an upper surface 4U of the conductive portion 4.

The variable resistor 300 includes a resistance substrate 1, which makes it possible to increase the resistance value of the fixed resistor section 5.

(4) Modifications of the First Embodiment (4.1) Modification 1
The resistance substrate 1 according to the first modification of the first embodiment is used in a variable resistor having a narrower rotation angle of a rotor than the variable resistor 300 according to the first embodiment. Therefore, as shown in FIG. 3 , the resistance substrate 1 according to the first modification has a different length of each of the resistive portion 3 and the conductive portion 4 from the resistance substrate 1 according to the first embodiment.

In the resistor substrate 1 according to the first modification, the central angle of the arc-shaped resistor portion 3 is 180 degrees. Also, in the resistor substrate 1 according to the first modification, the central angle of the arc-shaped conductive portion 4 is 180 degrees.

In the resistor substrate 1 according to the first modified example, the length of the fixed resistor section 5 can be made longer, and the resistance value of the fixed resistor section 5 can be made larger.

(4.2) Other Modifications In the resistance substrate 1 according to the first embodiment, the fixed resistance portion 5 is in contact with the first end 41 of the conductive portion 4, and the fixed resistance portion 5 is in contact with the second end 42 of the conductive portion 4, but this is not limited thereto. For example, the resistance substrate 1 may be configured such that the fixed resistance portion 5 is not in contact with the second end 42 of the conductive portion 4 as long as the fixed resistance portion 5 is in contact with at least the first end 41 of the conductive portion 4.

In addition, in the resistance substrate 1, the fixed resistance portion 5 is not limited to having both the first extension portion 51 and the second extension portion 52, but may be configured to have, for example, only the first extension portion 51 of the first extension portion 51 and the second extension portion 52.

In addition, each of the first extension portion 51 and the second extension portion 52 of the fixed resistance portion 5 is not limited to being arc-shaped, and may be, for example, linear.

(Embodiment 2)
The resistance board 1a according to the second embodiment will be described below with reference to Fig. 4. The resistance board 1a according to the second embodiment is used, for example, in place of the resistance board 1 in the variable resistor 300 according to the first embodiment. In the resistance board 1a according to the second embodiment, components similar to those in the resistance board 1 according to the first embodiment are given the same reference numerals and will not be described. In Fig. 4, the brush 10 provided in the variable resistor is indicated by a dashed line.

The resistance board 1a according to the second embodiment differs from the resistance board 1 according to the first embodiment in that the fixed resistance portion 5 is in contact with the inner edge 44 of the conductive portion 4. In the resistance board 1a according to the second embodiment, the fixed resistance portion 5 has a second extension portion 53 that extends from the tip of the extension portion 50 (first extension portion 50) along the inner edge 44 of the conductive portion 4. In the resistance board 1a according to the second embodiment, the tip of the second extension portion 53 of the fixed resistance portion 5 is in contact with the inner edge 44 of the conductive portion 4.

The resistance board 1a according to the second embodiment makes it possible to increase the resistance value of the fixed resistance section 5. More specifically, in the resistance board 1a according to the second embodiment, a part of the fixed resistance section 5 can be disposed on the board 2 between the first end 41 and the second end 42 of the conductive section 4 and inside the conductive section 4. As a result, the resistance board 1a according to the second embodiment can increase the area on the board 2 in which the fixed resistance section 5 can be disposed without increasing the size of the board 2, compared to a resistance board configured such that the fixed resistance section is connected to the outer periphery of a circular conductive section, and the length of the fixed resistance section 5 can be increased, making it possible to increase the resistance value of the fixed resistance section 5.

In addition, the resistor substrate 1a according to embodiment 2 can have a longer length of the fixed resistor section 5 than the resistor substrate 1 according to embodiment 1, making it possible to increase the resistance value of the fixed resistor section 5.

Embodiment 2 is merely one of various embodiments of the present disclosure. Various modifications of embodiment 2 are possible depending on the design, etc., as long as the object of the present disclosure can be achieved. For example, the fixed resistor portion 5 may have two second extension portions 53.

(Embodiment 3)
A resistor board 1b according to the third embodiment will be described below with reference to Fig. 5. The resistor board 1b according to the third embodiment is used, for example, in place of the resistor board 1 in the variable resistor 300 according to the first embodiment. In the resistor board 1b according to the third embodiment, components similar to those in the resistor board 1 according to the first embodiment are given the same reference numerals and will not be described. In Fig. 5, the brush 10 provided in the variable resistor is indicated by a dashed line.

The resistor substrate 1b according to the third embodiment differs from the resistor substrate 1 according to the first embodiment in that the conductive portion 4 is annular.

In the resistance substrate 1b according to the third embodiment, the conductive portion 4 has an outer edge 43 facing the resistance portion 3 and a recess 45 provided in the outer edge 43. The recess 45 includes a first surface 451, a second surface 452, and a third surface 453. The first surface 451 and the second surface 452 intersect in a direction along the outer periphery of the conductive portion 4 and are separated from each other in a direction along the outer periphery of the conductive portion 4. The third surface 453 connects the first surface 451 and the second surface 452 in a direction along the outer periphery of the conductive portion 4. The fixed resistance portion 5 is in contact with a portion 4533 of the third surface 453 of the recess 45 of the conductive portion 4 that is separated from the first surface 451 and the second surface 452. The portion 4533 is, for example, an intermediate portion of the third surface 453 where the distance from the first surface 451 is the same as the distance from the second surface 452, but it does not have to be an intermediate portion as long as it is separated from the first surface 451 and the second surface 452.

The resistance board 1b according to the third embodiment makes it possible to increase the resistance value of the fixed resistance section 5. More specifically, in the resistance board 1b according to the eighth aspect, a part of the fixed resistance section 5 can be disposed in a recess 45 provided on the outer edge 43 of the conductive section 4 on the board 2. As a result, the resistance board 1b according to the third embodiment can increase the area on the board 2 in which the fixed resistance section 5 can be disposed without increasing the size of the board 2, compared to a resistance board configured such that the fixed resistance section is connected to the outer periphery of a circular conductive section, and the length of the fixed resistance section 5 can be increased, making it possible to increase the resistance value of the fixed resistance section 5.

Embodiment 3 is merely one of various embodiments of the present disclosure. Various modifications of embodiment 3 can be made depending on the design, etc., as long as the object of the present disclosure can be achieved.

(Aspects)
The present specification discloses the following aspects.

The resistance substrate (1) according to the first aspect includes a substrate (2), a resistance portion (3), a conductive portion (4), a first terminal portion (6), a second terminal portion (7), a third terminal portion (8), and a fixed resistance portion (5). The substrate (2) has electrical insulation. The resistance portion (3) is formed on the substrate (2). The resistance portion (3) is arc-shaped and has a first end (31) and a second end (32). The conductive portion (4) is formed on the substrate (2) and is located inside the resistance portion (3). The conductive portion (4) is arc-shaped and has a first end (41) and a second end (42). The first terminal portion (6) is formed on the substrate (2). The first terminal portion (6) is connected to a portion of the first end (31) and the second end (32) of the resistance portion (3) that is closer to the first end (31). The second terminal portion (7) is formed on the substrate (2) and is connected to the conductive portion (4). The third terminal portion (8) is formed on the substrate (2). The third terminal portion (8) is connected to a portion of the resistance portion (3) that is closer to the second end (32) than the first end (31) or the second end (32). The fixed resistance portion (5) is formed on the substrate (2). The fixed resistance portion (5) connects the conductive portion (4) and the second terminal portion (7). The resistance value of the fixed resistance portion (5) is greater than the resistance value of the conductive portion (4). The fixed resistance portion (5) is in contact with the first end (41) of the conductive portion (4).

The resistance board (1) according to the first aspect makes it possible to increase the resistance value of the fixed resistance portion (5). More specifically, in the resistance board (1) according to the first aspect, a part of the fixed resistance portion (5) can be disposed between the first end (41) and the second end (42) of the conductive portion (4) on the board (2). This makes it possible to increase the area on the board (2) in which the fixed resistance portion (5) can be disposed without increasing the size of the board (2). This makes it possible to increase the length of the fixed resistance portion (5), making it possible to increase the resistance value of the fixed resistance portion (5).

In the resistance substrate (1) according to the second aspect, in the first aspect, the fixed resistance portion (5) is also in contact with the second end (42) of the conductive portion (4).

The resistance board (1) according to the second aspect has redundancy because the fixed resistance portion (5) is connected to the conductive portion (4) at two locations, the first end (41) and the second end (42) of the conductive portion (4). In other words, in the resistance board (1) according to the second aspect, even if a break occurs between the fixed resistance portion (5) and the first end 41 of the conductive portion (4) or between the fixed resistance portion (5) and the second end (42) of the conductive portion (4), for example, the function of the fixed resistance portion (5) connecting the second terminal portion (7) and the conductive portion (4) can be maintained.

In the resistance substrate (1) according to the third aspect, in the first or second aspect, the conductive portion (4) has an outer edge (43) facing the resistance portion (3) and an inner edge (44) located on the opposite side to the outer edge (43). The fixed resistance portion (5) has an extension portion (51). The extension portion (51) is located between the first end (41) and the second end (42) of the conductive portion (4) when viewed in the thickness direction of the substrate (2), and extends toward the first end (41) of the conductive portion (4). The width of the extension portion (51) is narrower than the width of the conductive portion (4). The distance between the extension portion (51) and the inner edge (44) of the conductive portion (4) is shorter than the distance between the extension portion (51) and the outer edge (43) of the conductive portion (4).

In the resistance board (1) according to the third aspect, the length of the fixed resistance portion (5) can be made longer and the resistance value of the fixed resistance portion (5) can be made larger than when the extension portion (51) is connected to the first end (41) of the conductive portion (4) over the entire width direction of the conductive portion (4) or when the extension portion (51) is closer to the outer edge (43) of the outer edge (43) and the inner edge (44) of the conductive portion (4).

The resistance board (1) according to the fourth aspect is the third aspect, in which the extension portion (51) is arc-shaped.

In the resistance substrate (1) according to the fourth aspect, the length of the extension portion (51) can be made longer than when the extension portion (51) is linear, and the resistance value of the fixed resistance portion (5) can be increased.

In the resistance substrate (1) according to the fifth aspect, in the third or fourth aspect, the fixed resistance portion (5) further has a second extension portion (52) in addition to the first extension portion (51) which is the extension portion (51). The second extension portion (52) is located between the first end (41) and the second end (42) of the conductive portion (4) when viewed from the thickness direction of the substrate (2). The second extension portion (52) extends toward the second end (42) of the conductive portion (4). The width of the second extension portion (52) is narrower than the width of the conductive portion (4). In the width direction of the conductive portion (4), the distance between the second extension portion (52) and the inner edge (44) of the conductive portion (4) is shorter than the distance between the second extension portion (52) and the outer edge (43) of the conductive portion (4).

In the resistance substrate (1) according to the fifth aspect, the length of the fixed resistance portion (5) can be made longer and the resistance value of the fixed resistance portion (5) can be made larger than when the second extension portion (52) is connected to the second end (42) of the conductive portion (4) over the entire width direction of the conductive portion (4) or when the second extension portion (52) is closer to the outer edge (43) of the outer edge (43) and the inner edge (44) of the conductive portion (4).

In the resistor substrate (1) according to the sixth aspect, in the fifth aspect, the second extension portion (52) is arc-shaped.

The resistance substrate (1) according to the sixth aspect can increase the length of the second extension portion (52) and increase the resistance value of the fixed resistance portion (5) compared to when the second extension portion (52) is linear.

The resistance substrate (1a) according to the seventh aspect includes a substrate (2), a resistance portion (3), a conductive portion (4), a first terminal portion (6), a second terminal portion (7), a third terminal portion (8), and a fixed resistance portion (5). The substrate (2) has electrical insulation. The resistance portion (3) is formed on the substrate (2). The resistance portion (3) is arc-shaped and has a first end (31) and a second end (32). The conductive portion (4) is formed on the substrate (2) and is located inside the resistance portion (3). The conductive portion (4) is arc-shaped and has a first end (41) and a second end (42). The first terminal portion (6) is formed on the substrate (2). The first terminal portion (6) is connected to a portion of the first end (31) and the second end (32) of the resistance portion (3) that is closer to the first end (31). The second terminal portion (7) is formed on the substrate (2) and is connected to the conductive portion (4). The third terminal portion (8) is formed on the substrate (2). The third terminal portion (8) is connected to a portion of the resistance portion (3) that is closer to the second end (32) out of the first end (31) and the second end (32). The fixed resistance portion (5) is formed on the substrate (2). The fixed resistance portion (5) connects the conductive portion (4) and the second terminal portion (7). The resistance value of the fixed resistance portion (5) is greater than the resistance value of the conductive portion (4). The conductive portion (4) has an outer edge (43) facing the resistance portion (3) and an inner edge (44) located on the opposite side to the outer edge (43). The fixed resistance portion (5) is in contact with the inner edge (44) of the conductive portion (4).

The resistance board (1a) according to the seventh aspect makes it possible to increase the resistance value of the fixed resistance portion (5). More specifically, in the resistance board (1a) according to the seventh aspect, a part of the fixed resistance portion (5) can be disposed on the board (2) between the first end (41) and the second end (42) of the conductive portion (4) and inside the conductive portion (4). This makes it possible to increase the area on the board (2) in which the fixed resistance portion (5) can be disposed without increasing the size of the board (2), and the length of the fixed resistance portion (5) can be increased, making it possible to increase the resistance value of the fixed resistance portion (5).

The resistance substrate (1b) according to the eighth aspect includes a substrate (2), a resistance portion (3), a conductive portion (4), a first terminal portion (6), a second terminal portion (7), a third terminal portion (8), and a fixed resistance portion (5). The substrate (2) has electrical insulation. The resistance portion (3) is formed on the substrate (2). The resistance portion (3) is arc-shaped and has a first end (31) and a second end (32). The conductive portion (4) is formed on the substrate (2) and is located inside the resistance portion (3). The conductive portion (4) is annular. The first terminal portion (6) is formed on the substrate (2). The first terminal portion (6) is connected to a portion of the resistance portion (3) that is closer to the first end (31) than the second end (32). The second terminal portion (7) is formed on the substrate (2) and is connected to the conductive portion (4). The third terminal portion (8) is formed on the substrate (2). The third terminal portion (8) is connected to a portion of the first end (31) and the second end (32) of the resistance portion (3) that is closer to the second end (32). The fixed resistance portion (5) is formed on the substrate (2). The fixed resistance portion (5) connects the conductive portion (4) and the second terminal portion (7). The resistance value of the fixed resistance portion (5) is greater than the resistance value of the conductive portion (4). The conductive portion (4) has an outer edge (43) facing the resistance portion (3) and a recess (45) provided in the outer edge (43). The recess (45) includes a first surface (451), a second surface (452), and a third surface (453). The first surface (451) and the second surface (452) intersect in a direction along the outer periphery of the conductive portion (4) and are separated from each other in a direction along the outer periphery of the conductive portion (4). The third surface (453) connects the first surface (451) and the second surface (452) in a direction along the outer periphery of the conductive portion (4). The fixed resistance portion (5) contacts a portion (4533) of the third surface (453) of the recess (45) of the conductive portion (4) that is away from the first surface (451) and the second surface (452).

The resistance board (1b) according to the eighth aspect makes it possible to increase the resistance value of the fixed resistance portion (5). More specifically, in the resistance board (1b) according to the eighth aspect, a part of the fixed resistance portion (5) on the board (2) can be disposed within a recess (45) provided on the outer edge 43 of the conductive portion (4). This makes it possible to increase the area on the board (2) in which the fixed resistance portion (5) can be disposed without increasing the size of the board (2), and the length of the fixed resistance portion (5) can be increased, making it possible to increase the resistance value of the fixed resistance portion (5).

The variable resistor (300) according to the ninth aspect includes a resistance substrate (1; 1a; 1b) according to any one of the first to eighth aspects, and a brush (10). The brush (10) is conductive. The brush (10) slides on the upper surface (3U) of the resistance portion (3) and the upper surface (4U) of the conductive portion (4).

The variable resistor (300) according to the ninth aspect makes it possible to increase the resistance value of the fixed resistance section (5).

1, 1a, 1b Resistance substrate 2 Substrate 21 Top surface 200 Outer periphery 201 First region 202 Second region 211 Through hole 3 Resistance portion 3U Top surface 31 First end 32 Second end 33 Outer edge 34 Inner edge 4 Conductive portion 4U Top surface 41 First end 42 Second end 43 Outer edge 44 Inner edge 45 Recess 451 First surface 452 Second surface 453 Third surface 4533 Part 5 Fixed resistance portion 5A Main body portion 50 Extension portion 51 Extension portion (first extension portion)
52 Second extension portion 6 First terminal portion 7 Second terminal portion 8 Third terminal portion 10 Brush 100 Fixed portion 101 First contact piece 102 Second contact piece 103 Hole 16 Wiring portion 18 Wiring portion 300 Variable resistor R1 Rotation direction

Claims (8)

An electrically insulating substrate;
an arc-shaped resistor portion formed on the substrate and having a first end and a second end;
an arc-shaped conductive portion formed on the substrate and positioned inside the resistor portion, the arc-shaped conductive portion having a first end and a second end;
a first terminal portion formed on the substrate and connected to a portion of the first end and the second end of the resistor portion that is closer to the first end;
A second terminal portion formed on the substrate and connected to the conductive portion;
a third terminal portion formed on the substrate and connected to a portion of the first end and the second end of the resistor portion that is closer to the second end;
a fixed resistor portion formed on the substrate, connecting the conductive portion and the second terminal portion, the fixed resistor portion having a resistance value larger than that of the conductive portion;
the fixed resistance portion is in contact with the first end of the conductive portion ,
The conductive portion is
an outer edge facing the resistor;
an inner edge opposite the outer edge,
The fixed resistance portion is
an extension portion located between the first end and the second end of the conductive portion when viewed in a thickness direction of the substrate and extending toward the first end of the conductive portion;
The width of the extension portion is narrower than the width of the conductive portion,
a distance between the extension portion and the inner edge of the conductive portion is shorter than a distance between the extension portion and the outer edge of the conductive portion;
Resistor board. The fixed resistance portion is also in contact with the second end of the conductive portion.
The resistor substrate according to claim 1 . The extension portion is arc-shaped.
The resistor substrate according to claim 1 . The fixed resistance portion is provided separately from the first extension portion which is the extension portion.
a second extension portion located between the first end and the second end of the conductive portion when viewed in a thickness direction of the substrate and extending toward the second end of the conductive portion,
The width of the second extension portion is narrower than the width of the conductive portion,
a distance between the second extension portion and the inner edge of the conductive portion is shorter than a distance between the second extension portion and the outer edge of the conductive portion;
The resistor substrate according to any one of claims 1 to 3. The second extension portion is arc-shaped.
The resistor substrate according to claim 4 . An electrically insulating substrate;
an arc-shaped resistor portion formed on the substrate and having a first end and a second end;
an arc-shaped conductive portion formed on the substrate and positioned inside the resistor portion, the arc-shaped conductive portion having a first end and a second end;
a first terminal portion formed on the substrate and connected to a portion of the first end and the second end of the resistor portion that is closer to the first end;
A second terminal portion formed on the substrate and connected to the conductive portion;
a third terminal portion formed on the substrate and connected to a portion of the first end and the second end of the resistor portion that is closer to the second end;
a fixed resistor portion formed on the substrate, connecting the conductive portion and the second terminal portion, the fixed resistor portion having a resistance value larger than that of the conductive portion;
The conductive portion is
an outer edge facing the resistor;
an inner edge opposite the outer edge,
The fixed resistance portion is
abutting the inner edge of the conductive portion without contacting the first end and the second end of the conductive portion;
Resistor board. An electrically insulating substrate;
an arc-shaped resistor portion formed on the substrate and having a first end and a second end;
a ring-shaped conductive portion formed on the substrate and positioned inside the resistor portion;
a first terminal portion formed on the substrate and connected to a portion of the first end and the second end of the resistor portion that is closer to the first end;
A second terminal portion formed on the substrate and connected to the conductive portion;
a third terminal portion formed on the substrate and connected to a portion of the first end and the second end of the resistor portion that is closer to the second end;
a fixed resistor portion formed on the substrate, connecting the conductive portion and the second terminal portion, the fixed resistor portion having a resistance value larger than that of the conductive portion;
The conductive portion is
an outer edge facing the resistor;
a recess in the outer edge,
The recessed portion is
a first surface and a second surface that intersect in a direction along an outer periphery of the conductive portion and are spaced apart from each other in the direction along the outer periphery of the conductive portion;
a third surface connecting the first surface and the second surface in a direction along the outer periphery of the conductive portion,
The fixed resistance portion is
the third surface of the recess of the conductive portion is in contact with a portion of the recess that is away from the first surface and the second surface;
Resistor board. A resistor substrate according to any one of claims 1 to 7,
a brush having electrical conductivity and sliding on an upper surface of the resistor portion and an upper surface of the conductive portion;
Variable resistor.

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