Reaction force generating member for a key switch device

A key switch device comprising:

• an operation member to be depressed;
• a switch disposed below the operation member;
• and
• an elastic dome provided between the operation member and the switch, the elastic dome including an outer dome and an inner dome integrally formed with each other,
• wherein the outer dome has a first load displacement characteristic in which a depression load increases until the outer dome performs elastic buckling deformation, and the depression load decreases depending on depression of the operation member after the outer dome performs the elastic buckling deformation,
• wherein the inner dome has a second load displacement characteristic in which the depression load increases after the inner dome comes into contact with the switch,
• wherein a combined load of the first load displacement characteristic and the second load displacement characteristic decreases while the operation member is depressing after the outer dome performs the elastic buckling deformation, and
• wherein a decreasing amount of the depression load of the combined load is smaller than that of the depression load of the first load displacement characteristic while the operation member is depressing after the outer dome performs the elastic buckling deformation.