Variable resistor and electronic device

A variable resistor comprising:

• a main body and a rotating part that are vertically separated and face each other, wherein
• the main body includes:
• a substrate having a first main surface vertically separated from a second main surface provided on a back side thereof, and having a through hole vertically penetrating the first main surface and the second main surface;
• a first conductive portion and a second conductive portion provided on the first main surface, arranged apart from each other in a circumferential direction relative to a vertical rotation axis, and to which a predetermined voltage is applied;
• a resistor body provided on the first main surface and connected to each of the first conductive portion and the second conductive portion;
• and
• a third conductive portion provided on the first main surface and provided with a connection terminal extending away from the first main surface, and
• the rotating part includes:
• an opposing part including an opposing surface that faces the first main surface and rotates around the vertical rotation axis,
• an electrode formed in an annular shape along the circumference direction and configured to slide on the connection terminal as the opposing part rotates, which is provided on the opposing surface on a first main surface side of the opposing part, and located on one side away from the resistor body than the through hole in the orthogonal direction orthogonal to the circumferential direction;
• and
• a slider connected to the electrode and configured to slide on an annular portion that extends continuously in the circumferential direction around the through hole and formed by (i) the resistor body alone or (ii) the resistor body and a portion of at least one of the first conductive portion and the second conductive portion.

An electronic device, for determining a rotation position of a slider of a variable resistor in a circumferential direction, the electronic device comprising:

• a main body and a rotating part that are vertically separated from each other and face each other, wherein
• the main body includes:
• a substrate having:
• a first main surface facing vertically upward, a second main surface facing vertically downward, and a through hole vertically penetrating the first main surface and the second main surface in one direction;
• a first conductive portion and a second conductive portion provided on the first main surface, arranged apart from each other in a circumferential direction, and to which a predetermined voltage is applied;
• a resistor body provided on the first main surface and connected to each of the first conductive portion and the second conductive portion;
• an electrode provided on the first main surface and located on a through-hole side relative to the resistor body;
• and
• a third conductive portion provided on each of the second main surface and a partition wall surface and configured to partition the through hole and connect to the electrode, and
• the rotating part includes:
• an opposing part that faces the first main surface in vertical direction and rotates in the circumferential direction around a vertical rotation axis, the slider located on an opposing surface on a first main surface side of the opposing part, and configured to conductively slide on the electrode as the opposing part rotates in the circumferential direction, and to conductively slide on an annular portion that extends continuously along the circumferential direction around the through hole and formed by (i) the resistor body alone or (ii) the resistor body and a portion of at least one of the first conductive portion and the second conductive portion;
• a rotation direction memory part configured to store the rotation direction of the part;
• a voltage change detection part configured to detect an amount of change in voltage applied to a portion of the resistor body between the first conductive portion and the slider;
• and
• a position determination part configured to determine the rotation position of the slider in the circumferential direction based on an output results of the rotation direction storage unit and the voltage change detection unit.

An electronic device, for determining a rotation position of a slider of a variable resistor in a circumferential direction, the electronic device comprising:

• a main body and a rotating part that are vertically separated from each other and face each other, wherein
• the main body includes:
• a substrate having a first main surface facing vertically upward, a second main surface facing vertically downward, and a through hole vertically penetrating the first main surface and the second main surface;
• a first conductive portion and a second conductive portion provided on the first main surface, arranged apart from each other in a circumferential direction, and to which a predetermined voltage is applied;
• a resistor body provided on the first main surface and connected to each of the first conductive portion and the second conductive portion;
• and
• a third conductive portion provided on the first main surface and provided with a connection terminal extending away from the first main surface, and
• the rotating part includes:
• an opposing part including an opposing surface that faces the first main surface, and that rotates in the circumferential direction;
• and
• an electrode formed in an annular shape along the circumference direction and configured to conductively slide on the connection terminal as the opposing part rotates, which is provided on the opposing surface on a first main surface side of the opposing part, and located on one side away from the resistor body than the through hole in the orthogonal direction orthogonal to the circumferential direction, and
• the slider is connected to the electrode and is configured to conductively slide on the annular portion that extends continuously in the circumferential direction around the through hole and formed by (i) the resistor body alone or (ii) the resistor body and a portion of at least one of the first conductive portion and the second conductive portion, wherein
• the electronic device is further provided with:
• a rotation direction detection memory part that stores the rotation direction of the part;
• a voltage change detection part configured to detect an amount of change in voltage applied to a portion of the resistor body between the first conductive portion and the slider;
• and
• a position determination part configured to determine the rotation position of the slider in the circumferential direction based on an output results of the rotation direction storage unit and the voltage change detection unit.