Variable focus lens
First Claim
1. A variable focus lens including a substantially cylindrical fluid chamber having a cylinder wall, the fluid chamber including a first fluid (A) and an axially displaced second fluid (B), the fluids being non-miscible, in contact over a meniscus (14) and having different indices of refraction, a fluid contact layer (10) arranged on the inside of the cylinder wall, a first electrode (2) separated from the first fluid and second fluid by the fluid contact layer, a second electrode (12) acting on the second fluid, the fluid contact layer having a wettability by the second fluid which varies under the application of a voltage between the first electrode and the second electrode, such that the shape of the meniscus varies in dependence on the said voltage, wherein the wettability of the fluid contact layer by the second fluid is substantially equal on both sides of the intersection of the meniscus with the contact layer when no voltage is applied between the first and second electrodes.
2 Assignments
0 Petitions
Accused Products
Abstract
A variable focus lens comprising a first fluid (A) and a second, non-miscible, fluid (B) in contact over a meniscus. A first electrode (2) separated from the fluid bodies by a fluid contact layer (10), and a second electrode (12) in contact with the first fluid to cause an electrowetting effect whereby the shape of the meniscus is altered. The fluid contact layer has a substantially cylindrical inner wall.
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Citations
16 Claims
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1. A variable focus lens including
a substantially cylindrical fluid chamber having a cylinder wall, the fluid chamber including a first fluid (A) and an axially displaced second fluid (B), the fluids being non-miscible, in contact over a meniscus (14) and having different indices of refraction, a fluid contact layer (10) arranged on the inside of the cylinder wall, a first electrode (2) separated from the first fluid and second fluid by the fluid contact layer, a second electrode (12) acting on the second fluid, the fluid contact layer having a wettability by the second fluid which varies under the application of a voltage between the first electrode and the second electrode, such that the shape of the meniscus varies in dependence on the said voltage, wherein the wettability of the fluid contact layer by the second fluid is substantially equal on both sides of the intersection of the meniscus with the contact layer when no voltage is applied between the first and second electrodes.
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12. An optical scanning device according to claim 12, wherein said lens is arranged to correct for spherical aberrations arising during the scanning of different information layer depths in optical record carriers being scanned.
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13. A method of operating a variable focus lens including a substantially cylindrical fluid chamber having a cylinder wall, the fluid chamber including a first fluid (A) and an axially displaced second fluid (B), the fluids being non-miscible, in contact over a meniscus (14) and having different indices of refraction,
a fluid contact layer (10) arranged on the inside of the cylinder wall, a first electrode (2) separated from the first fluid and second fluid by the fluid contact layer, a second electrode (12) acting on the second fluid, the wettability of the fluid contact layer by the second fluid being substantially equal on both sides of the intersection of the meniscus with the contact layer when no voltage is applied between the first and second electrodes, the wettability of the fluid contact layer by the second fluid varying under the application of a voltage between the first electrode and the second electrode, the method comprising controlling the said voltage to change the shape of the meniscus.
Specification