Power generation necklaces with field shaping systems
An augmented reality system including a necklace and a contact lens display can be used to project information from the contact lens display onto the retina of the wearer's eye. In one example, the necklace generates a time-varying magnetic field (TVMF) that provides energy and information to the contact lens display via inductive coupling. The necklace can be configured to decrease the amount of energy absorbed by the body of the wearer and increase power transfer to the contact lens display. The necklace includes a conductive loop and one or more bucking loops that are positioned to increase transmitted energy while reducing the amount of energy absorbed by the human body. The amount of current travelling in one direction through the loops of the necklace is greater than the amount of current travelling in the opposite direction through the loops of the necklace. The necklace can include any number of signal generators and winding patterns for the loops.
1. A system for providing power to an electronic contact lens via inductive coupling, the system comprising:
a necklace configured to be worn against a body of a necklace wearer;
one or more first conductive loops extending along a band of the necklace;
one or more second conductive loops also extending along the band of the necklace, wherein the one or more first conductive loops are positioned closer to the electronic contact lens along a y-axis than the one or more second conductive loops when the necklace is worn against the body of the necklace wearer, and the y-axis is orthogonal to a plane defined by the one or more first conductive loops; and
one or more driver circuits to drive a first total current through the one or more first conductive loops in a first direction to generate a first magnetic field and to drive a second total current through the one or more second conductive loops in an opposite second direction to generate a second magnetic field, wherein:
the first total current travelling through the one or more first conductive loops in the first direction has a different strength than the second total current travelling through the one or more second conductive loops in the second direction,
the first magnetic field and the second magnetic field sum to produce a resulting magnetic field, and
the one or more first conductive loops are separated from the one or more second conductive loops by a distance along the y-axis such that interference between the first and second magnetic fields (a) increases a strength of the resulting magnetic field on a side of the necklace closer to the electronic contact lens, and (b) decreases a strength of the resulting magnetic field on a side of the necklace away from the electronic contact lens; whereby (x) more power is inductively coupled to the electronic contact lens, and (y) less power is absorbed by a region of the wearer's body against which the necklace is worn.
2. The system of claim 1 , wherein the one or more first conductive loops are connected in series with the one or more second conductive loops, the first conductive loops and the second conductive loops wound in opposite directions from each other.
3. The system of claim 1 , wherein the one or more first conductive loops include a first number of conductive loops and the one or more second conductive loops include a second number of conductive loops less than the first number.
4. The system of claim 1 , wherein the first total current that flows through the one or more first conductive loops is greater than the second total current that flows through the one or more second conductive loops.
5. The system of claim 1 , wherein:
the necklace comprises a first surface configured to be placed against the body of the necklace wearer and a second surface opposite to the first surface, and
the one or more first conductive loops and the one or more second conductive loops are positioned between the first surface and the second surface of the necklace.
6. The system of claim 1 , wherein the one or more first conductive loops comprise:
an upper conductive loop; and
a lower conductive loop positioned both farther away along the y-axis from the electronic contact lens than the upper conductive loop, and between the upper conductive loop and the one or more second conductive loops.
7. The system of claim 1 , wherein the one or more first conductive loops comprise:
a first loop; and
a second loop, the first loop and second loop positioned approximately equidistant along the y-axis from the region of the wearer's body against which the necklace is worn.
8. The system of claim 1 , wherein the one or more second conductive loops and the region of the wearer's body against which the necklace is worn are separated along the y-axis by a threshold distance.
9. The system of claim 1 , wherein the one or more second conductive loops are spaced apart along the y-axis from the region of the wearer's body against which the necklace is worn by at least a width of the one or more second conductive loops.
10. The system of claim 1 , wherein the one or more first conductive loops comprise an upper conductive loop, and the one or more second conductive loops comprise a lower conductive loop, the lower conductive loop positioned along the y-axis between the upper conductive loop and the region of the wearer's body against which the necklace is worn.
11. The system of claim 1 , wherein the one or more driver circuits further comprises:
a first driver circuit to drive the first total current through the one or more first conductive loops; and
a second driver circuit to drive the second total current through the one or more second conductive loops.
12. The system of claim 1 , wherein the one or more first conductive loops and the one or more second conductive loops are concentric.
13. The system of claim 1 , wherein the electronic contact lens further comprises:
a contact lens display for displaying images to the necklace wearer, the contact lens display receiving power from the inductively coupled necklace.
14. A system for providing power to an electronic contact lens via inductive coupling, the system comprising:
a necklace configured to be worn against a body of a necklace wearer;
a first conductive loop extending along a band of the necklace;
a second conductive loop also extending along the band of the necklace, wherein the first conductive loop is positioned closer to the electronic contact lens along a y-axis than the second conductive loop when the necklace is worn against the body of the necklace wearer, and the y-axis is orthogonal to a plane defined by the first conductive loop; and
one or more drivers circuits to drive a first current through the first conductive loop in a first direction to generate a first magnetic field and to drive a second current through the second conductive loop in an opposite direction to generate a second magnetic field, wherein:
the first magnetic field and the second magnetic field sum to produce a resulting magnetic field, and
the first conductive loop is separated from the second conductive loop by a distance along the y-axis such that interference between the first and second magnetic fields (a) increases a strength of the resulting magnetic field on a side of the necklace closer to the electronic contact lens, and (b) decreases a strength of the resulting magnetic field on a side of the necklace away from the electronic contact lens; whereby (x) more power is inductively coupled to the electronic contact lens, and (y) less power is absorbed by a region of the wearer's body against which the necklace is worn.
15. The system of claim 14 , wherein the first current that flows through the first conductive loop is greater than the second current that flows through the second conductive loop.
16. The system of claim 14 , wherein the first conductive loop and the second conductive loop are concentric.
17. The system of claim 14 , wherein the one or more driver circuits further comprises:
a first driver circuit to drive the first current through the first conductive loop; and
a second driver circuit to drive the second current through the second conductive loop.
18. The system of claim 14 , wherein:
the necklace comprises a first surface configured to be placed against the body of the necklace wearer and a second surface opposite to the first surface and closer along the y-axis to the contact lens, and
the first conductive loop and the second conductive loop are between the first surface and the second surface of the necklace.
19. The system of claim 18 , wherein the second conductive loop and the first surface of the necklace are separated by a threshold distance along the y-axis.
20. The system of claim 14 , wherein the first conductive loop is connected in series with the second conductive loop, the first conductive loop and the second conductive loop wound in opposite directions from each other.