Keyswitch device and keyboard
AssigneeFujitsu Component Limited
InventorsHiromi OHTSUKA, Daisuke TAGA, Takuya SAITOU, Momosuke NAKAHARA
Life of this patent
Estimating the term…
Abstract
A keyswitch device which is provided with a support mechanism which supports a keytop in a movable manner, and a membrane sheet which has a plurality of upper electrodes and a plurality of lower electrodes which respectively correspond to the plurality of the upper electrodes and which form contact pairs with the corresponding upper electrodes. A plurality of contact pairs are arranged for a single keytop. The rubber cup pushes the plurality of contact pairs which are arranged for the single keytop.
Claims7
A reaction force generating member comprising:
- a first dome that gives a reaction force to an operation member according to a depression of the operation member;
- and
- a second dome that includes a hemispherical bowl part disposed inside the first dome, and a projection projecting downward from a center of the bowl part and depressing a switch disposed below the operation member, wherein
- the first dome has a first load displacement characteristic in which a depression load of the operation member increases until the first dome performs buckling deformation according to the depression of the operation member, the depression load of the operation member reaches a peak load, and the depression load of the operation member decreases after the buckling deformation,
- the second dome has a second load displacement characteristic in which the depression load of the operation member nonlinearly increases according to a depression amount of the operation member, and
- when the depression load of the operation member in a total of the first and the second load displacement characteristics of the first dome and the second dome decreases and before the depression load of the operation member reaches a bottom load which is a minimum load after the peak load, the projection turns on the switch, and
- wherein the second load displacement characteristic is lower in a load increase rate than a third load displacement characteristic in which the depression load linearly increases according to the depression amount of the operation member.
A key switch device comprising:
- an operation member to be depressed;
- a switch disposed under the operation member;
- and
- a reaction force generating member, provided between the operation member and the switch, including:
- a first dome that gives a reaction force to the operation member according to the depression of the operation member;
- and
- a second dome that includes a hemispherical bowl part disposed inside the first dome, and a projection projecting downward from a center of the bowl part and depressing the switch disposed below the operation member,
- wherein the switch is turned on when a stroke of the operation member is larger than a first stroke corresponding to a peak load and smaller than a second stroke corresponding to a bottom load after the peak load, and
- wherein the second dome has a first load displacement characteristic in which a depression load of the operation member nonlinearly increases according to a depression amount of the operation member, the first load displacement characteristic being lower in a load increase rate than a second load displacement characteristic in which the depression load linearly increases according to the depression amount of the operation member.
Dependencies are inferred from the claim text.