Swing type input apparatus
View Patent ↗A swing type input apparatus includes a housing, an operation knob rotatably supported by the housing, and a detecting unit detecting an angle of rotation of the knob. The detecting unit includes a circuit substrate intersecting the rotation center line of the knob, a magnetic sensor on an extension of the circuit substrate, a magnet holder driven by and rotated with the knob, a magnet held by the magnet holder such that the magnet intersects the rotation center line and is close to and faces the magnetic sensor, and a magnetic shield case which covers the magnet and the magnetic sensor and is a boxy assembly of first and second shield cases. The boundary between the first and second shield cases is positioned so as not to overlap the magnet. A bent grounding tab in the second shield case is electrically connected to a grounding conductor of a sub substrate.
1. A swing type input apparatus comprising:
a housing;
an operation knob swingably supported by the housing;
a circuit substrate received in the housing so as to intersect the rotation center line of the operation knob;
a magnetic sensor attached to the circuit substrate;
a magnet holder driven by the operation knob such that the magnet holder is rotated integrally with the operation knob;
a magnet held by the magnet holder such that the magnet is positioned so as to intersect the rotation center line of the operation knob and is close to and faces the magnetic sensor; and
a magnetic shield case fixed to the circuit substrate so as to cover at least both of the magnetic sensor and the magnet, wherein the magnetic shield case includes an assembly of a first shield case and a second shield case combined in a box,
the distance from the boundary between the first and second shield cases to the rotation center line of the operation knob is set longer than the distance from an outer edge of the magnet to the rotation center line of the operation knob,
a grounding tab extending substantially orthogonal to the circuit substrate is provided for either of the first and second shield cases, and
the grounding tab is electrically connected to a grounding conductor of the circuit substrate.
2. The apparatus according to claim 1 , wherein
the magnet holder includes a driven portion driven by the operation knob, a holding portion holding the magnet, and a shaft portion connecting the driven portion and the holding portion, the axis of the shaft portion being made coincide with the rotation center line of the operation knob,
the first and second shield cases define an opening having substantially the same size as that of the cross section of the shaft portion, and
the shaft portion extends through the opening.
3. The apparatus according to claim 2 , wherein an attachment member comprising synthetic resin is attached in a predetermined position of the circuit substrate, and
the attachment member includes a first engagement portion positioning the magnetic shield case and a second engagement portion positioned in the housing.