US 12,379,526 B2
Relating to variable focal power optical elements, a variable focal power optical device, a display module for an augmented reality headset and an augmented reality headset
Robert Edward Stevens, Eynsham (GB); Simon Peter Horrocks, Eynsham (GB); and Thomas Norman Llyn Jacoby, Eynsham (GB)
Assigned to ADLENS LIMITED
Appl. No. 16/963,007
Filed by ADLENS LIMITED, Eynsham (GB)
PCT Filed Jan. 17, 2019, PCT No. PCT/GB2019/050131
§ 371(c)(1), (2) Date Jul. 17, 2020,
PCT Pub. No. WO2019/141990, PCT Pub. Date Jul. 25, 2019.
Claims priority of application No. 1800933 (GB), filed on Jan. 19, 2018.
Prior Publication US 2020/0341172 A1, Oct. 29, 2020
Int. Cl. G02B 3/14 (2006.01); G02B 27/01 (2006.01); G02C 7/08 (2006.01)
CPC G02B 3/14 (2013.01) [G02C 7/085 (2013.01); G02B 2027/0178 (2013.01)] 25 Claims
OG exemplary drawing
 
1. An adjustable focal power optical device comprising a hybrid injection-compression variable focal power optical element and an electronic control system, the optical element comprising:
a fluid-filled envelope having a rigid first wall, a second wall opposite the first wall which comprises a distensible membrane held under tension around its edge by a peripheral support ring, and a collapsible side wall extending between the first and second walls, the first and second walls being coupled together in such a manner as to permit movement of the peripheral support ring towards or away from the first wall, the envelope being filled with a substantially incompressible fluid;
a port for introducing more or withdrawing some of the substantially incompressible fluid into or from the envelope;
at least one spacing control device for controlling the spacing between the peripheral support ring or one or more regions thereof and the first wall, the spacing being controllable between a minimum spacing and a maximum spacing; and
an electronically operable injector for introducing or withdrawing fluid from the envelope via the port;
whereby the electronic control system is configured to receive a selected focal power from an input device and, in response to receipt of the selected focal power, to adjust the focal power of the optical element to the selected focal power;
wherein the focal power of the optical element is adjustable between a maximum focal power and a minimum focal power, an intermediate focal power being between the maximum focal power and the minimum focal power;
wherein when the focal power of the optical element is in a range between the minimum focal power and the intermediate focal power, the electronic control system is configured to adjust the focal power by changing the spacing between the support ring or the one or more regions thereof and the first wall using the at least one spacing control device;
wherein when the focal power of the optical element is in a range between the maximum focal power and the intermediate focal power, the electronic control system is configured to adjust the focal power by changing the volume of the fluid in the envelope using the electronically operable injector whilst the spacing between the support ring or the one or more regions thereof and the first wall is maintained at the minimum spacing.