Fluid lens operational feedback using sensor signal
Disclosed devices may include a membrane having a membrane curvature, a substrate, an enclosure (defined at least in part by the membrane and the substrate) enclosing a fluid, a peripheral structure configured to adjust the membrane curvature, and a sensor configured to provide a sensor signal that is a function of the membrane curvature. The device may also include a controller configured to control the membrane curvature using a control signal. For example, the control signal may be provided to at least one actuator. The controller may receive a sensor signal from the sensor and modify the control signal based on the sensor signal. Examples also include associated methods and systems.
1. A device, comprising:
a membrane having a membrane curvature;
a substrate;
an enclosure defined at least in part by the membrane and the substrate and enclosing a lens fluid;
a peripheral structure configured to adjust the membrane curvature;
a sensor configured to provide a sensor signal that is a function of the membrane curvature;
a controller configured to:
adjust the membrane curvature using a control signal;
receive the sensor signal from the sensor; and
modify the control signal based on the sensor signal;
a light source, configured to provide a light beam when energized; and
a light sensor, configured to receive light from the light beam, wherein:
the sensor signal comprises a light sensor signal provided by the light sensor; and
the light source is configured to direct the light beam into the enclosure.
2. The device of claim 1 , wherein:
the membrane is an elastic membrane;
the substrate is an optically transparent substrate; and
the device has an optical power based on the membrane curvature.
3. The device of claim 2 , wherein the sensor signal is a function of the optical power of the device.
4. The device of claim 1 , wherein the sensor signal is a light sensor signal or a capacitance sensor signal.
5. The device of claim 1 , wherein the light sensor is configured to receive the light from a portion of the light beam that is totally internally reflected within the enclosure.
6. The device of claim 1 , wherein the light sensor is configured to receive at least a portion of the light beam that is totally internally reflected from a surface of the membrane.
7. The device of claim 1 , wherein:
the light beam is a divergent light beam;
a portion of the divergent light beam is totally internally reflected from a surface of the membrane;
the portion of the divergent light beam is a function of the membrane curvature; and
the light sensor is configured to receive the portion of the divergent light beam.
8. The device of claim 1 , wherein the light source comprises a laser or a light-emitting diode.
9. The device of claim 1 , wherein the light beam is a visible light beam or near-IR light beam.
10. The device of claim 1 , wherein the light sensor comprises a photodiode or photoresistor.
11. A device, comprising:
a membrane having a membrane curvature;
a substrate;
an enclosure defined at least in part by the membrane and the substrate and enclosing a lens fluid;
a peripheral structure configured to adjust the membrane curvature;
a sensor configured to provide a sensor signal that is a function of the membrane curvature; and
a controller configured to:
adjust the membrane curvature using a control signal;
receive the sensor signal from the sensor; and
modify the control signal based on the sensor signal,
wherein the device further comprises:
a first electrode;
a second electrode; and
a capacitance sensor configured to provide a capacitance sensor signal based on a capacitance between the first electrode and the second electrode,
wherein the sensor signal is based on the capacitance sensor signal.
12. The device of claim 11 , wherein the first electrode and the second electrode are generally coplanar.
13. The device of claim 11 , wherein the first electrode is supported by the substrate.
14. The device of claim 13 , wherein the second electrode is supported by the substrate.
15. The device of claim 13 , wherein the second electrode is supported by the membrane.
16. The device of claim 11 , wherein the capacitance sensor signal is a ratiometric capacitance signal based on a ratio of the capacitance between the first electrode and the second electrode to a second capacitance.
17. The device of claim 11 , wherein:
the membrane comprises an electroactive material located between a pair of electrodes;
the membrane curvature is adjustable based on an electric potential applied between the pair of electrodes; and
the pair of electrodes comprises the first electrode.