CPC G02B 3/14 (2013.01) [G02B 26/004 (2013.01); G02B 27/0172 (2013.01); G02C 7/085 (2013.01); G02B 2027/0178 (2013.01)] | 26 Claims |
1. A variable focusing power fluid-filled lens or mirror assembly comprising a fluid-filled envelope and a supporting structure therefor; the fluid-filled envelope being constituted by a first wall which is formed of a distensible elastic membrane having an exterior optical surface of variable curvature, a second wall which is spaced from the first wall on a z-axis which is generally perpendicular to the membrane, and a collapsible peripheral side wall which extends between the first and second walls, and being filled with a substantially incompressible fluid; a membrane holding structure which is attached to a peripheral edge of membrane for holding the membrane under tension, the membrane holding structure defining a plurality of discrete control points spaced around the peripheral edge of membrane where the position of the peripheral edge of the membrane relative to the second wall on the z-axis is controlled and permitting bending of the peripheral edge of the membrane in a plane defined by the z-axis and a tangent to the peripheral edge of the membrane; the plurality of control points including a plurality of dynamic actuation points; and an actuation mechanism for displacing the edge of the membrane on the z-axis relative to the second wall at each of the dynamic actuation points to control the shape of the membrane; wherein the actuation mechanism comprises a plurality of first cam members which are connected to the membrane holding structure and associated with respective dynamic actuation points, a cam belt disposed circumjacent to the edge of the membrane which comprises a plurality of spaced second cam members, each second cam member being engaged with a corresponding one of the first cam members for controlling the position of the edge of the membrane on the z-axis at the respective dynamic actuation point, a cam belt support which supports the cam belt for bidirectional rotation around the z-axis relative to the membrane and a coupling for drivably connecting the cam belt to a selectively operable driver; and wherein the cam belt forms a complete loop circumjacent to the edge of the membrane.
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