INPUT DEVICE AND METHOD OF MANUFACTURING MODULE UNIT FOR INPUT DEVICE
An input device comprises a wiring board having stationary contacts and a module unit placed on the wiring board. The module unit has a structure formed integrally with actuating key portions, movable contacts, cushioning members and protruding portions. The movable contacts are disposed under the actuating key portions, and actuated by a push-on operation of the actuating key portions. The cushioning members are disposed in a space between a lower surface of the actuating key portions and an upper surface of a movable contact retainer bearing the movable contacts to make the space shrinkable when subjected to the push-on operation whereas it maintains an uniform height when not subjected to the push-on operation. The protruding portions depress top center portions of the movable contacts. The input device includes switch elements, each comprising the movable contact and the stationary contact, and the switch element is actuated by the push-on operation on the actuating key portion.
1 . An input device comprising:
a wiring board provided with a stationary contact; and
a module unit placed on the wiring board,
wherein the module unit comprises:
an actuating key portion;
a movable contact disposed under the actuating key portion, and actuated by a push-on operation of the actuating key portion;
cushioning members disposed in a space between a lower surface of the actuating key portion and an upper surface of a movable contact retainer bearing the movable contact to make the space shrinkable when subjected to the push-on operation whereas the cushioning members maintaining an uniform space height when not subjected to the push-on operation; and
a protruding portion for depressing a top center portion of the movable contact,
wherein the actuating key portion, the movable contact, the cushioning members, and the protruding portion are integrally formed, and
further wherein the input device has a switch element comprising the movable contact and the stationary contact, and
the switch element is actuated by the push-on operation through the actuating key portion.
2 . The input device of claim 1 , wherein the actuating key portion is provided with a capacitive sensor bonded to it to constitute a coordinate input controller for accepting an input of coordinate data according to a change in capacitance responsive to a movement of a finger of an operator.
3 . The input device of claim 1 , wherein the cushioning members are formed into a pillar shape and disposed at positions around the switch element at equal distances from the center thereof and at equal angles with respect to each other.
4 . The input device of claim 3 , wherein each of the cushioning members is disposed at a position midpoint along a line between centers of two adjoining switch elements.
5 . The input device of claim 2 , wherein the capacitive sensor of the coordinate input controller comprises a sheet-form sensor element made of an electrode printed on a PET (polyethylene terephthalate) film, and the movable contact retainer comprises a sheet-form movable contact assembly bearing the movable contact on an underside surface thereof.
6 . A method of manufacturing a module unit for an input device, the method comprising the steps of:
preparing a capacitive sensor and a movable contact assembly, and printing a resin paste mixed with a foaming agent on one of the capacitive sensor and the movable contact assembly in a prescribed pattern corresponding to an arrangement of cushioning members;
placing the other one of the capacitive sensor and the movable contact assembly in a manner to confront the one bearing the resin paste printed thereon with a space kept therebetween of a dimension equal to a given height of the cushioning members; and
foaming and hardening the resin paste to form the cushioning members bonded to the capacitive sensor and the movable contact assembly while maintaining the height dimension fixed by the other one of the capacitive sensor and the movable contact assembly.
7 . The method of manufacturing a module unit of claim 6 , wherein the step of placing the other one of the capacitive sensor and the movable contact assembly comprises a process of placing a height setting member formed into a dimension equal to the height of the cushioning members between the capacitive sensor and the movable contact assembly.
8 . The method of manufacturing a module unit of claim 6 , wherein the step of placing the other one of the capacitive sensor and the movable contact assembly comprises a process of placing the other one of the capacitive sensor and the movable contact assembly in a manner to bring top surfaces of a plurality of convex portions provided on the movable contact assembly or upper ends of protruding portions formed on the top surfaces into contact with the other one.