Linear motion mechanism formed integrally

A linear motion mechanism comprising:

• an elastic elliptical ring, wherein one end of a major axis of the elastic elliptical ring is fixed and the other end of the major axis is movable, the elastic elliptical ring transforming a displacement in a direction of a minor axis of the elastic elliptical ring to a linear motion displacement in the direction of the major axis;
• an operating member arranged to deform the elastic elliptical ring in the direction of the minor axis, the operating member comprising a pair of spring members sandwiching the elastic elliptical ring in the direction of the minor axis;
• a movable member fixed to the other end of the major axis;
• and
• an elastic support member arranged to elastically support the movable member to move along the major axis, wherein
• when the pair of spring members are pressed or stretched in mutually opposite input directions by an input displacement, the elastic elliptical ring is deformed by the displacement in the direction of the minor axis,
• a ratio between the input displacement and the linear motion displacement of the movable member is determined by a combination of a spring constant of the elastic elliptical ring and a different spring constant of the pair of spring members, and
• the different spring constant of the pair of spring members is smaller than the spring constant of the elastic elliptical ring.