Angular velocity sensor
First Claim
1. An angular velocity sensor comprising:
- a vibrator located in an x-y plane specified by an x direction and a y direction that are orthogonal to each other;
a substrate that is separated away from the vibrator in a z direction perpendicular to the x-y plane;
an anchor device extended from the substrate to the x-y plane in which the vibrator is located;
a linkage beam device that links the anchor device with the vibrator, the linkage beam device being able to twist about the y direction;
an excitation portion that vibrates the vibrator along the z direction; and
a detection portion that detects an angular velocity based on a displacement along the x direction of the vibrator, whereinthe vibrator includes a linkage region that is linked with the linkage beam device, the linkage region becoming a wave node when the vibrator vibrates along the z direction,the vibrator includes up-down weights, inclination weights linked to the linkage beam device, and twist beams that link the inclination weights to the up-down weights, the twist beams being able to twist about the y direction,a left side and a right side are respectively referred to as one and an other of two sides along the x direction viewed from a central weight, which is one of the inclination weights and located at a center in the x direction of the vibrator;
a unit weight portion is defined as including one up-down weight, one inclination weight next to the one up-down weight, and twist beams linking the one up-down weight with the one inclination weight;
the vibrator includesa left unit weight, which includes at least one unit weight portion, on the left side anda right unit weight, which includes at least one unit weight portion, on the right side;
a number of the at least one unit weight portion of the left unit weight and a number of the at least one unit weight portion of the right unit weight are identical to each other such that the left unit weight and the right unit weight are arranged along the x direction and symmetrical with respect to the central weight of the vibrator;
the excitation portion vibrates the left unit weight and the right unit weight with opposite phases, respectively; and
the detection portion detects an angular velocity based on a displacement along the x direction of each of the left unit weight and the right unit weight;
the up-down weight includes a first frame portion having an outer face linked with the twist beams, a second frame portion located in a range surrounded by an inner face of the first frame portion, and detection beams that link the first frame portion with the second frame portion, the detection beams having flexibility along the x direction; and
the detection portion includesfirst detection electrodes formed in an inner face of the second frame portion,second detection electrodes, which are linked with the anchor device, the second detection electrodes facing the first detection electrodes in either the x direction or the y direction, andan angular velocity detection portion that detects an angular velocity based on changes of electrostatic capacities of capacitors formed between the first detection electrodes and the second detection electrodes.
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Accused Products
Abstract
An angular velocity sensor includes a vibrator located along x-y plane specified by x direction and y direction that are orthogonal to each other; a substrate that is separated away from the vibrator along z direction perpendicular to the x-y plane; an anchor device extended from the substrate to the x-y plane in which the vibrator is located; a linkage beam device that links the anchor device to the vibrator, the linkage beam being able to twist about the y direction; an excitation portion that vibrates the vibrator along the z direction; and a detection portion that detects an angular velocity based on a displacement along the x direction of the vibrator. The vibrator includes a linkage region to link with the linkage beam device, and the linkage region becomes a wave node when the vibrator vibrates along the z direction.
27 Citations
31 Claims
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1. An angular velocity sensor comprising:
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a vibrator located in an x-y plane specified by an x direction and a y direction that are orthogonal to each other; a substrate that is separated away from the vibrator in a z direction perpendicular to the x-y plane; an anchor device extended from the substrate to the x-y plane in which the vibrator is located; a linkage beam device that links the anchor device with the vibrator, the linkage beam device being able to twist about the y direction; an excitation portion that vibrates the vibrator along the z direction; and a detection portion that detects an angular velocity based on a displacement along the x direction of the vibrator, wherein the vibrator includes a linkage region that is linked with the linkage beam device, the linkage region becoming a wave node when the vibrator vibrates along the z direction, the vibrator includes up-down weights, inclination weights linked to the linkage beam device, and twist beams that link the inclination weights to the up-down weights, the twist beams being able to twist about the y direction, a left side and a right side are respectively referred to as one and an other of two sides along the x direction viewed from a central weight, which is one of the inclination weights and located at a center in the x direction of the vibrator; a unit weight portion is defined as including one up-down weight, one inclination weight next to the one up-down weight, and twist beams linking the one up-down weight with the one inclination weight; the vibrator includes a left unit weight, which includes at least one unit weight portion, on the left side and a right unit weight, which includes at least one unit weight portion, on the right side; a number of the at least one unit weight portion of the left unit weight and a number of the at least one unit weight portion of the right unit weight are identical to each other such that the left unit weight and the right unit weight are arranged along the x direction and symmetrical with respect to the central weight of the vibrator; the excitation portion vibrates the left unit weight and the right unit weight with opposite phases, respectively; and the detection portion detects an angular velocity based on a displacement along the x direction of each of the left unit weight and the right unit weight; the up-down weight includes a first frame portion having an outer face linked with the twist beams, a second frame portion located in a range surrounded by an inner face of the first frame portion, and detection beams that link the first frame portion with the second frame portion, the detection beams having flexibility along the x direction; and the detection portion includes first detection electrodes formed in an inner face of the second frame portion, second detection electrodes, which are linked with the anchor device, the second detection electrodes facing the first detection electrodes in either the x direction or the y direction, and an angular velocity detection portion that detects an angular velocity based on changes of electrostatic capacities of capacitors formed between the first detection electrodes and the second detection electrodes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An angular velocity sensor comprising:
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a vibrator located in an x-y plane specified by an x direction and a y direction that are orthogonal to each other; a substrate that is separated away from the vibrator in a z direction perpendicular to the x-y plane; an anchor device extended from the substrate to the x-y plane in which the vibrator is located; a linkage beam device that links the anchor device with the vibrator, the linkage beam device being able to twist about the y direction; an excitation portion that vibrates the vibrator along the z direction; and a detection portion that detects an angular velocity based on a displacement along the x direction of the vibrator, wherein the vibrator includes up-down weights, inclination weights linked to the linkage beam device, and twist beams that link the inclination weights to the up-down weights, the twist beams being able to twist about the y direction, a left side and a right side are respectively referred to as one and an other of two sides along the x direction viewed from a central weight, which is one of the inclination weights and located at a center in the x direction of the vibrator, a unit weight portion is defined as including one up-down weight, one inclination weight next to the one up-down weight, and twist beams linking the one up-down weight with the one inclination weight, the vibrator includes a left unit weight, which includes at least one unit weight portion, on the left side, and a right unit weight, which includes at least one unit weight portion, on the right side, a number of the at least one unit weight portion of the left unit weight and a number of the at least one unit weight portion of the right unit weight are identical to each other such that the left unit weight and the right unit weight are arranged along the x direction and symmetrical with respect to the central weight of the vibrator, the linkage beam device includes a main frame portion surrounding the vibrator, first linkage beams which link the anchor device with the main frame portion, and second linkage beams which link the vibrator with the main frame portion, the vibrator includes linkage regions that link the second linkage beams with the inclination weight of each of the left unit weight and the right unit weight that are farthest from the central weight located at the center of the vibrator, the linkage region becoming a wave node when the vibrator vibrates along the z direction, and the inclination weight of each of the left unit weight and the right unit weight that are farthest from the central weight is divided into a projection portion and a base portion by a penetrating direction that is deviated from a center in the x direction of the inclination weight towards the central weight, the penetrating direction penetrating along the y direction through the linkage region in the inclination weight, the base portion being farther from the central weight than the projection portion and broader than the projection portion, permitting an end portion of the base portion along the x direction separating away from the central weight to serve as a free end. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. An angular velocity sensor comprising:
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a vibrator located in an x-y plane specified by an x direction and a y direction that are orthogonal to each other; a substrate that is separated away from the vibrator in a z direction perpendicular to the x-y plane; an anchor device extended from the substrate to the x-y plane in which the vibrator is located; a linkage beam device that links the anchor device with the vibrator, the linkage beam device being able to twist about the y direction; an excitation portion that vibrates the vibrator along the z direction; and a detection portion that detects an angular velocity based on a displacement along the x direction of the vibrator, wherein the vibrator includes a linkage region that is linked with the linkage beam device, the linkage region becoming a wave node when the vibrator vibrates along the z direction, the vibrator includes up-down weights, inclination weights linked to the linkage beam device, and twist beams that link the inclination weights to the up-down weights, the twist beams being able to twist about the y direction, a left side and a right side are respectively referred to as one and an other of two sides along the x direction viewed from a central weight, which is one of the inclination weights and located at a center in the x direction of the vibrator, a unit weight portion is defined as including one up-down weight, one inclination weight next to the one up-down weight, and twist beams linking the one up-down weight with the one inclination weight, the vibrator includes a left unit weight, which includes at least one unit weight portion, on the left side and a right unit weight, which includes at least one unit weight portion, on the right side, a number of the at least one unit weight portion of the left unit weight and a number of the at least one unit weight portion of the right unit weight are identical to each other such that the left unit weight and the right unit weight are arranged along the x direction and symmetrical with respect to the central weight of the vibrator, the excitation portion vibrates the left unit weight and the right unit weight with opposite phases, respectively, the detection portion detects an angular velocity based on a displacement along the x direction of each of the left unit weight and the right unit weight, the linkage beam device includes a main frame portion surrounding the vibrator, first linkage beams which link the anchor device to the main frame portion, and second linkage beams which link the vibrator to the main frame portion, the second linkage beams, which link the vibrator to the main frame portion, extend along the y direction while being configured to twist about the y direction, and the first linkage beams, which link the anchor device to the main frame portion, extend along the y direction while having flexibility along the x direction. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification