Optical lens displacement systems
View Patent ↗The present invention provides optical systems, devices and methods which utilize one or more electroactive polymer actuators to adjust an optical parameter of the optical device or system.
1. A lens displacement system comprising:
a lens unit comprising at least one lens positioned along a focal axis, the lens unit having a linear bearing surface;
an electroactive polymer actuator positioned adjacent the lens unit wherein activation of the actuator moves the lens unit along the focal axis;
a linear guide adjacent to the linear bearing surface for maintaining the position of the lens unit;
multiple lens stages, each stage comprising a lens,
wherein the lens unit is carried by a lens driver mechanism whereby activation of the actuator moves the lens driver mechanism, wherein the lens unit comprises an afocal lens assembly and wherein the lens driver mechanism translates the multiple stages at different rates.
2. The lens displacement system of claim 1 , wherein the ratio of a translation rate of one lens stage to that of another lens stage defines a telescoping action.
3. The lens displacement system of claim 1 , wherein each lens is seated within a lens plate carried by the lens driver mechanism.
4. The lens displacement system of claim 3 , wherein the lens driver mechanism further comprises a pair of linkages extending between lens plates.
5. The lens displacement system of claim 1 , further comprising a backstop to prevent movement of the lens unit beyond an infinity focus position.
6. The lens displacement system of claim 1 , further comprising at least one light filter along the focal axis.
7. The lens displacement system of claim 1 , further comprising a translucent cover over a forward end of the lens unit.
8. The lens displacement system of claim 1 , wherein the lens unit configured for calibrating the focus of the lens unit.
9. The lens displacement system of claim 8 , wherein a housing portion of the lens unit comprises at least one indentation for receiving a calibration tool.
10. The lens displacement system of claim 1 , further comprising a sensor for sensing the position of the lens unit.
11. The lens displacement system of claim 10 , wherein the sensor comprises a pair of spaced apart electrodes, the first electrode positioned on an outer surface of the lens unit and the second electrode positioned on a surface of the linear guide facing the outer surface of the lens unit, wherein position of the lens unit relative to linear guide changes the capacitance across the electrodes.
12. The lens displacement system of claim 1 , further comprising a heating element positioned for controlling the temperature of a least a portion of the electroactive polymer actuator.
13. The lens displacement system of claim 1 , wherein the lens unit has a cylindrical barrel configuration and the linear bearing surface is an outer surface of the lens barrel.
14. The lens displacement system of claim 1 , wherein the lens unit comprises a plurality of lenses, wherein a distal most lens is a focusing lens and two or more lenses proximal thereto are afocal lenses.
15. The lens displacement system of claim 1 , wherein the electroactive polymer actuator comprises a film wherein the film is configured to deflect in only one direction when activated.
16. The lens displacement system of claim 15 , wherein the film comprises an elastomeric dielectric layer bonded to a backing material, the backing material having a higher elastic modulus than the dielectric layer.