Switch

A switch comprising:

• a click spring that generates a tactile action by being pressing down and comprises a circumferential edge and a movable contact;
• a spring holding sheet attached on the click spring;
• a switch base which is provided with a first stationary contact and a second stationary contact, and which supports the spring holding sheet;
• and
• a nub disposed on the spring holding sheet and having a non-linear acting load to displacement characteristic;
• wherein the circumferential edge of the click spring is continuously in contact with the first stationary contact;
• wherein the movable contact of the click spring is configured to contact the second stationary contact at a time of the tactile action;
• and
• wherein a spring constant k11, a spring constant k3, a spring constant k12, a displacement S1, and a displacement s11 satisfy following inequalities:
• k11<k3,
• k12>k3,
• and
• 0<s11<S1,
• where:
• the spring constant k11 is a gradient of a tangent line at an origin point of an acting load to displacement characteristic curve of the nub,
• the displacement S1 is a displacement corresponding to a peak acting load in an acting load to displacement characteristic curve of the click spring and the spring holding sheet,
• the spring constant k3 is a gradient of a line connecting a point corresponding to the peak acting load and an origin point of the characteristic curve of the click spring and the spring holding sheet,
• the spring constant k12 is a gradient of a tangent line at an arbitrary point within a non-linear portion of the characteristic curve of the nub, and
• the displacement s11 is a displacement corresponding to an intersection point of the line having the gradient k11 and the line having the gradient k12.