Push button device, keyboard device, and electronic apparatus
A push button device can stabilize an operation of a guide mechanism and can enhance product quality. A keyboard device includes the push button device and electronic apparatus includes the keyboard device. A key switch that is a push button device includes a key cap as a push button, a base plate, and a guide mechanism. The guide mechanism includes an outer frame member and an inner member. An outer frame member has a pair of inner surfaces opposed to each other with interposition of an opening in which the inner member is disposed, and each of the pair of inner surfaces is provided with a bearing hole to serve as a first engagement part. The inner member has a pair of outer surfaces opposed to the pair of inner surfaces of the outer frame member, and each of the pair of outer surfaces is provided with a rotation shaft to be a second engagement part. An outer peripheral surface of the rotation shaft has a tapered portion whose outer diameter gradually decreases in an insertion direction of the bearing hole.
1. A push button device comprising:
a base part;
a guide mechanism disposed on an upper surface of the base part; and
a push button that is guided by the guide mechanism to be vertically movable, wherein
the guide mechanism includes:
an outer frame member having a first end rotatably supported on the base part and a second end rotatably supported on the push button, and
an inner member disposed inside the outer frame member and diagonally braced to the outer frame member, the inner member having a first end rotatably supported on the push button and a second end rotatably supported on the base part,
the outer frame member has a pair of inner surfaces opposed to each other with an opening therebetween, each of the inner surfaces having a first engagement part that consists of one of a bearing hole and a rotation shaft,
the inner member has a pair of outer surfaces opposed to the pair of inner surfaces of the outer frame member, each of the outer surfaces has a second engagement part that consists of an other one of the bearing hole and the rotation shaft, the second engagement part being rotatably engaged with the first engagement part,
the rotation shaft has an outer peripheral surface including a tapered portion whose outer diameter gradually decreases in an insertion direction of the bearing hole,
the bearing hole has only one inner diameter along an entire length, in the insertion direction, of the bearing hole, and
the tapered portion has a proximal outer diameter larger than the inner diameter of an opening edge of the bearing hole, has a distal outer diameter smaller than the inner diameter of the opening edge of the bearing hole, and has an outer peripheral surface in contact with the opening edge of the bearing hole.
2. The push button device according to claim 1 , wherein:
the rotation shaft has a base portion that includes the tapered portion and has a distal end portion that includes a cylindrical shaft portion, and
in the rotation shaft, the shaft portion is inserted in the bearing hole, and a part of the tapered portion is inserted in the bearing hole.
3. The push button device according to claim 1 , wherein:
the inner member is a frame member having an opening inside the inner member.
4. A keyboard device comprising a plurality of push button devices, wherein at least one push button device includes:
a base part;
a guide mechanism disposed on an upper surface of the base part; and
a push button that is guided by the guide mechanism to be vertically movable, wherein
the guide mechanism includes:
an outer frame member having a first end rotatably supported on the base part and a second end rotatably supported on the push button, and
an inner member disposed inside the outer frame member and diagonally braced to the outer frame member, the inner member having a first end rotatably supported on the push button and a second end rotatably supported on the base part,
the outer frame member has a pair of inner surfaces opposed to each other with an opening therebetween, each of the inner surfaces having a first engagement part that consists of one of a bearing hole and a rotation shaft,
the inner member has a pair of outer surfaces opposed to the pair of inner surfaces of the outer frame member, each of the outer surfaces has a second engagement part that consists of an other one of the bearing hole and the rotation shaft, the second engagement part being rotatably engaged with the first engagement part,
the rotation shaft has an outer peripheral surface including a tapered portion whose outer diameter gradually decreases in an insertion direction of the bearing hole,
the bearing hole has only one inner diameter along an entire length, in the insertion direction, of the bearing hole, and
the tapered portion has a proximal outer diameter larger than the inner diameter of an opening edge of the bearing hole, has a distal outer diameter smaller than the inner diameter of the opening edge of the bearing hole, and has an outer peripheral surface in contact with the opening edge of the bearing hole.
5. The keyboard device according to claim 4 , further comprising:
a frame partitioning adjacent push buttons.
6. An electronic apparatus comprising:
a chassis equipped with a keyboard device having:
a plurality of push button devices, wherein at least one push button device includes:
a base part;
a guide mechanism disposed on an upper surface of the base part; and
a push button that is guided by the guide mechanism to be vertically movable, wherein
the guide mechanism includes:
an outer frame member having a first end rotatably supported on the base part and a second end rotatably supported on the push button, and
an inner member disposed inside the outer frame member and diagonally braced to the outer frame member, the inner member having a first end rotatably supported on the push button and a second end rotatably supported on the base part,
the outer frame member has a pair of inner surfaces opposed to each other with an opening therebetween, each of the inner surfaces having a first engagement part that consists of one of a bearing hole and a rotation shaft,
the inner member has a pair of outer surfaces opposed to the pair of inner surfaces of the outer frame member, each of the outer surfaces has a second engagement part that consists of an other one of the bearing hole and the rotation shaft, the second engagement part being rotatably engaged with the first engagement part, and
the rotation shaft has an outer peripheral surface including a tapered portion whose outer diameter gradually decreases in an insertion direction of the bearing hole,
the bearing hole has only one inner diameter along an entire length, in the insertion direction, of the bearing hole, and
the tapered portion has a proximal outer diameter larger than the inner diameter of an opening edge of the bearing hole, has a distal outer diameter smaller than the inner diameter of the opening edge of the bearing hole, and has an outer peripheral surface in contact with the opening edge of the bearing hole; and
a display chassis including a display that displays in accordance with an input operation to at least one of the push button devices of the keyboard device, the display chassis being rotatably connected to the chassis.