Actuator
AssigneeNidec Corporation
InventorTakuro Iguchi
Life of this patent
Estimating the term…
Abstract
An actuator includes a swing portion swingable about a first axis orthogonal to a central axis extending vertically and about a second axis orthogonal to the first axis and intersecting the central axis. An angle detector includes a pair of first angle detection elements above a non-magnetic structure and extending in the second axis direction with the first axis interposed therebetween when viewed from the central axis direction, and a pair of second angle detection elements extending in the first axis direction with the second axis interposed therebetween. Each of the first angle detection elements and each of the second angle detection elements include a columnar magnetic structure between the swing portion and the non-magnetic structure in the central axis direction, and a detection coil along the outer periphery of the magnetic structure.
Claims20
An actuator comprising:
- a swing portion that is electrically conductive;
- a frame portion to support the swing portion such that the swing portion is swingable about a first axis orthogonal to a central axis extending vertically;
- a support portion to support the frame portion such that the frame portion is swingable about a second axis orthogonal to the first axis and intersecting the central axis;
- a magnet below the swing portion;
- a drive assembly including a drive coil defined by a lead wire wound around a stator core in the support portion and extending in the central axis direction;
- a non-magnetic structure between the swing portion and the drive coil in the central axis direction;
- and
- an angle detector to detect a swing angle of the swing portion;
- wherein
- the angle detector includes a pair of first angle detection elements extending in the second axis direction with the first axis interposed therebetween and a pair of second angle detection elements extending in the first axis direction with the second axis interposed therebetween when viewed from the central axis direction, and the angle detector is above the non-magnetic structure;
- and
- each of the first angle detection elements and each of the second angle detection elements include:
- a columnar magnetic structure between the swing portion and the non-magnetic structure in the central axis direction;
- and
- a detection coil extending along an outer periphery of the magnetic structure;
- and
- the drive coil is inside an outer edge of the non-magnetic structure when viewed from the central axis direction.
An actuator comprising:
- a swing portion that is electrically conductive;
- a frame portion to support the swing portion such that the swing portion is swingable about a first axis orthogonal to a central axis extending vertically;
- a support portion to support the frame portion such that the frame portion is swingable about a second axis orthogonal to the first axis and intersecting the central axis;
- a magnet below the swing portion;
- a drive assembly including a drive coil defined by a lead wire wound around a stator core in the support portion and extending in the central axis direction;
- a non-magnetic structure between the swing portion and the drive coil in the central axis direction;
- and
- an angle detector to detect a swing angle of the swing portion;
- wherein
- the angle detector includes a pair of first angle detection elements extending in the second axis direction with the first axis interposed therebetween and a pair of second angle detection elements extending in the first axis direction with the second axis interposed therebetween when viewed from the central axis direction, and the angle detector is above the non-magnetic structure;
- each of the first angle detection elements and each of the second angle detection elements include:
- a columnar magnetic structure between the swing portion and the non-magnetic structure in the central axis direction;
- and
- a detection coil extending along an outer periphery of the magnetic structure;
- the magnetic structure extends upward along the central axis direction;
- each of the first angle detection element and the second angle detection element includes a capacitor connected in parallel to the detection coil;
- the actuator further includes:
- a frequency processor connected to the detection coil to acquire a resonance frequency of a resonance circuit including the detection coil and the capacitor while causing a current to flow through the detection coil, and acquire a swing angle of the swing portion based on a fluctuation of the resonance frequency;
- a wiring substrate is between the non-magnetic structure and the swing portion in the central axis direction;
- the magnetic structure protrudes upward from an upper surface of the wiring substrate;
- and
- the detection coil is a wiring pattern provided on the wiring substrate.
Dependencies are inferred from the claim text.