High-voltage H-bridge control circuit for a lens driver of an electronic ophthalmic lens
A lens driver or lens driver circuitry for an ophthalmic apparatus comprising an electronic system which actuates a variable-focus optic is disclosed herein. The lens driver is part of an electronic system incorporated into the ophthalmic apparatus. The electronic system includes one or more batteries or other power sources, power management circuitry, one or more sensors, clock generation circuitry, control algorithms and circuitry, and lens driver circuitry. The lens driver circuitry includes one or more power sources, one or more high voltage generators and one or more switching circuits. Specifically, the lens driver comprises an H-bridge/H-bridge controller for providing the proper voltage, including polarity, to drive the electronic included in the ophthalmic apparatus.
1. An ophthalmic apparatus comprising:
an ophthalmic lens for use in at least one of in or on the eye;
an optic element incorporated into the ophthalmic lens, the optic element configured for at least one of vision correction and vision enhancement and having one or more of electronically controlled focal length, electronically controlled light transmission, and electronically controlled polarization; and
an electronic system incorporated into the ophthalmic lens, the electronic system including:
a power source;
an H-bridge circuit configured to control a voltage supplied to the optic element, to reverse the polarity of a voltage supplied to the optic element and to short the optic element, the H-bridge circuit including first and second lower switches implemented as N-channel MOSFET transistors, and first and second upper P-channel MOSFET switches;
an H-bridge control circuit used to control the first and second upper P-channel MOSFET switches using level shifter cells and configured to be a high-impedance circuit thereby preventing a loading of the power source, the level shifter cells comprising buffers, a capacitor coupling circuit, and a charge pump cell, wherein the capacitors level shift between a low voltage and a high voltage and transfer the charge to the charge pump cell, the charge pump cell provides an activation voltage for the first and second upper P-channel MOSFET switches, and an active turn-off circuit comprising control switches designed to deactivate the first and second upper P-channel MOSFET switches as necessary by activating an additional level shifter circuit to activate the control switches, and a cross-coupled switch circuit between the outputs of the two level shifter cells thereby ensuring only one of the first and second upper P-channel MOSFET switches is on at a time; and
a system controller configured to provide control and timing signals for the electronic system, wherein the power source provides a voltage to sources of the first and second upper P-channel MOSFET transistor and to the H-Bridge control circuit.
2. The ophthalmic apparatus according to claim 1 , wherein the ophthalmic device comprises a contact lens.
3. The ophthalmic apparatus according to claim 2 , wherein the contact lens comprises a soft contact lens.
4. The ophthalmic apparatus according to claim 2 , wherein the contact lens comprises a hybrid soft/rigid contact lens.
5. The ophthalmic apparatus according to claim 1 , wherein the ophthalmic device comprises an intraocular lens.
6. The ophthalmic apparatus according to claim 1 , wherein the optic element operates in at least two focal lengths.
7. The ophthalmic apparatus according to claim 1 , wherein the electronic system is implemented on an integrated circuit.
8. The ophthalmic apparatus according to claim 1 , wherein the optic element comprises a liquid meniscus lens.
9. The ophthalmic apparatus according to claim 1 , wherein the optic element comprises a liquid crystal lens.
10. The ophthalmic apparatus according to claim 1 , wherein the power source comprises a battery.
11. The ophthalmic apparatus according to claim 7 , wherein the integrated circuit is incorporated onto a circuit board.
12. The ophthalmic apparatus according to claim 11 , wherein the circuit board is configured as an annular ring.
13. The ophthalmic apparatus according to claim 12 , wherein the annular ring is formed into a conical section for incorporation into a contact lens.
14. The ophthalmic apparatus according to claim 12 , wherein the annular ring is formed into a conical section for incorporation into an intraocular lens.
15. The ophthalmic apparatus according to claim 1 , wherein the optic element operates in at least two states of light transmission.
16. The ophthalmic apparatus according to claim 1 , wherein the optic element operates in at least two states of light polarization.
17. An ophthalmic apparatus comprising:
an ophthalmic lens for use in at least one of in or on the eye;
an optic element incorporated into the ophthalmic lens, the optic element configured for at least one of vision correction and vision enhancement and having one or more of electronically controlled focal length, electronically controlled light transmission, and electronically controlled polarization; and
an electronic system incorporated into the ophthalmic lens, the electronic system including:
a power source;
an H-bridge circuit configured to control a voltage supplied to the optic element, to reverse the polarity of a voltage supplied to the optic element and to short the optic element, the H-bridge circuit including first and second lower switches implemented as N-channel MOSFET transistors, and first and second upper P-channel MOSFET switches;
an H-bridge control circuit used to control the first and second upper P-channel MOSFET switches using level shifter cells and configured to be a high-impedance circuit thereby preventing a loading of the power source, the level shifter cells comprising buffers, a capacitor coupling circuit, and a charge pump cell, wherein the capacitors level shift between a low voltage and a high voltage and transfer the charge to the charge pump cell, the charge pump cell provides an activation voltage for the first and second upper P-channel MOSFET switches, and an active turn-off circuit comprising control switches designed to deactivate the first and second upper P-channel MOSFET switches as necessary by activating a cross-coupled switch circuit between the outputs of the two level shifter cells thereby ensuring only one of the first and second upper P-channel MOSFET switches is on at a time; and
a system controller configured to provide control and timing signals for the electronic system, wherein the power source provides a voltage to gates of the first and second upper P-channel MOSFET transistor and to the H-Bridge control circuit.
18. The ophthalmic apparatus according to claim 17 , wherein the ophthalmic device comprises a contact lens.
19. The ophthalmic apparatus according to claim 18 , wherein the contact lens comprises a soft contact lens.
20. The ophthalmic apparatus according to claim 18 , wherein the contact lens comprises a hybrid soft/rigid contact lens.
21. The ophthalmic apparatus according to claim 17 , wherein the ophthalmic device comprises an intraocular lens.
22. The ophthalmic apparatus according to claim 17 , wherein the optic element operates in at least two focal lengths.
23. The ophthalmic apparatus according to claim 17 , wherein the electronic system is implemented on an integrated circuit.
24. The ophthalmic apparatus according to claim 17 , wherein the optic element comprises a liquid meniscus lens.
25. The ophthalmic apparatus according to claim 17 , wherein the optic element comprises a liquid crystal lens.
26. The ophthalmic apparatus according to claim 17 , wherein the power source comprises a battery.
27. The ophthalmic apparatus according to claim 23 , wherein the integrated circuit is incorporated onto a circuit board.
28. The ophthalmic apparatus according to claim 27 , wherein the circuit board is configured as an annular ring.
29. The ophthalmic apparatus according to claim 28 , wherein the annular ring is formed into a conical section for incorporation into a contact lens.
30. The ophthalmic apparatus according to claim 28 , wherein the annular ring is formed into a conical section for incorporation into an intraocular lens.