Abstract: An augmented reality display unit for use in an augmented reality headset or the like comprising front and rear variable focusing power compression liquid lens assemblies (220, 230) in mutual optical alignment on an optical axis (O), a transparent waveguide display (240) interposed between the front and rear liquid lens assemblies (220, 230) and a selectively operable adjustment mechanism for adjusting the focusing powers of the front and rear compression liquid lens assemblies (220, 230); wherein each of the front and rear compression liquid lens assemblies (220, 230) comprises a fluid-filled envelope (225, 235) having a first wall formed by a distensible elastic membrane (226, 236) that is held under tension around its edge by a peripheral support ring, a second substantially rigid wall (223, 233) formed by or supported on an inner surface of a transparent plate or a hard lens of fixed focusing power, and a collapsible side wall (227, 237), the membrane forming an optical surface of variable optical power,

Abstract: Adjustable focal length eyewear (11) comprising two lenses (21, 22) that are mounted to a frame (14, 15, 16) for supporting the lenses (21, 22) in front of a user's eyes. At least one of the lenses (21, 22) is a variable focal length lens of the kind comprising two superposed lens elements (31, 41) having cooperating optical surfaces that are shaped such that the focal length of the variable focal length lens (21, 22) is variable according to the relative lateral disposition of the lens elements (31, 41). One of the lens elements (31) is fixedly mounted to the frame (14, 15, 16) and the other lens element (41) is movable manually relative to the fixed lens element (31) for varying the focal length of the variable focal length lens (21, 22).

Abstract: A method of assembling an adjustable fluid-filled lens assembly comprising biaxially tensioning an elastomeric membrane to a surface tension of greater than 180 N/m, typically greater than 1000 N/m; thermally conditioning the tensioned membrane, e.g., for one hour at a temperature of about 80° C., to accelerate relaxation of the membrane; mounting the membrane to a peripheral support structure whilst maintaining the tension in the membrane; assembling the mounted membrane with one or more other components to form an enclosure with the membrane forming one wall of the enclosure; and thereafter filling the enclosure with a fluid. The membrane may be formed from an aromatic polyurethane, and the fluid may be a phenylated siloxane. In some embodiments, the membrane is able to hold a substantially constant surface tension of at least 180 N/m for a period of at least 12 months.

Abstract: A method of fabricating a lens element for an adjustable power lens of the kind comprising two lens elements that are slidable relative to one other in a direction transverse the optical axis of the lens and have respective lens surfaces that are shaped to act together to form a corrective lens, the power of which varies according to the relative disposition of the two lens elements, the method comprising the steps of forming a lens puck having two opposite faces, which are shaped to form opposite lens surfaces of one of the lens elements of the adjustable power lens, the puck having at least one alignment feature, and thereafter edging the puck to a desired eye shape with reference to the alignment feature.

Abstract: A method of fabricating a lens element for an adjustable power lens of the kind comprising two lens elements that are slidable relative to one other in a direction transverse the optical axis of the lens and have respective lens surfaces that are shaped to act together to form a corrective lens, the power of which varies according to the relative disposition of the two lens elements, the method comprising the steps of forming a lens puck having two opposite faces, which are shaped to form opposite lens surfaces of one of the lens elements of the adjustable power lens, the puck having at least one alignment feature, and thereafter edging the puck to a desired eye shape with reference to the alignment feature.

Abstract: An augmented reality display unit for use in an augmented reality headset or the like comprising front and rear variable focusing power compression liquid lens assemblies (220, 230) in mutual optical alignment on an optical axis (O), a transparent waveguide display (240) interposed between the front and rear liquid lens assemblies (220, 230) and a selectively operable adjustment mechanism for adjusting the focusing powers of the front and rear compression liquid lens assemblies (220, 230); wherein each of the front and rear compression liquid lens assemblies (220, 230) comprises a fluid-filled envelope (225, 235) having a first wall formed by a distensible elastic membrane (226, 236) that is held under tension around its edge by a peripheral support ring, a second substantially rigid wall (223, 233) formed by or supported on an inner surface of a transparent plate or a hard lens of fixed focusing power, and a collapsible side wall (227, 237), the membrane forming an optical surface of variable optical power,

Abstract: A method of assembling an adjustable fluid-filled lens assembly comprising biaxially tensioning an elastomeric membrane to a surface tension of greater than 180 N/m, typically greater than 1000 N/m; thermally conditioning the tensioned membrane, e.g., for one hour at a temperature of about 80° C., to accelerate relaxation of the membrane; mounting the membrane to a peripheral support structure whilst maintaining the tension in the membrane; assembling the mounted membrane with one or more other components to form an enclosure with the membrane forming one wall of the enclosure; and thereafter filling the enclosure with a fluid. The membrane may be formed from an aromatic polyurethane, and the fluid may be a phenylated siloxane. In some embodiments, the membrane is able to hold a substantially constant surface tension of at least 180 N/m for a period of at least 12 months.

Abstract: An adjustable fluid-filled lens or minor assembly 100 comprising a fluid-filled envelope and a supporting structure therefor; the fluid-filled envelope being constituted by a first wall that is formed of a distensible elastic membrane 15 having an exterior optical surface of variable focusing power, a second wall 18 that is spaced from the first wall on a z-axis, and a collapsible peripheral side wall 17 that extends between the first and second walls, and being filled with a substantially incompressible fluid 16; a membrane holding structure 14 that is attached to a peripheral edge of membrane 15 for holding the membrane under tension; and one or more selectively operable actuator assemblies r1, r2, r3 for moving one or more corresponding regions of the peripheral edge of the membrane on the z-axis towards and away from the second wall 18 for controlling the profile of the peripheral edge of the membrane; wherein the or each actuator assembly comprises a connecting member 91, 92, 93 that is attached to the m

Abstract: A variable focusing power fluid-filled lens or minor assembly (100a) comprising a fluid-filled envelope and a supporting structure (18) therefor; the fluid-filled envelope being constituted by a first wall that is formed of a distensible elastic membrane (15) having an exterior optical surface (151) of variable focusing power, a second wall (183) that is spaced from the first wall on a z-axis which is generally perpendicular to the membrane, and a collapsible peripheral side wall (17) that extends between the first and second walls (15, 183), and being filled with a substantially incompressible fluid (16); a membrane holding structure (14) that is attached to a peripheral edge of membrane for holding the membrane under tension, the membrane holding structure defining a plurality of discrete control points spaced around the peripheral edge of membrane where the position of the peripheral edge of the membrane relative to the second wall on the z-axis is controlled and permitting bending of the peripheral edge o

Abstract: Methods of filling an envelope (16) of a compression-type adjustable optical device (10), such as a liquid lens or mirror, which is formed in part by a distensible membrane (11) having an exterior optical surface, with a substantially incompressible fluid (15) to a predetermined optical power or radius of curvature; the methods comprising pumping fluid into the envelope (16) under vacuum through a fluid supply conduit (23) in fluid communication with an interior of the envelope (16) while allowing air to escape from the envelope through a fluid overflow conduit (26) in fluid communication with the interior of the envelope (16); continuing to pump fluid (15) into the envelope (16) to cause the membrane (11) to distend to an optical power of the optical device (10) that is greater than the predetermined optical power while allowing excess fluid (15) to escape from the envelope through the overflow device (26); slowing or stopping the supply of fluid to the envelope (16), thereby to allow the membrane (11) progr

Abstract: A method of assembling an adjustable fluid-filled lens assembly comprising biaxially tensioning an elastomeric membrane to a surface tension of greater than 180 N/m, typically greater than 1000 N/m; thermally conditioning the tensioned membrane, e.g., for one hour at a temperature of about 80° C., to accelerate relaxation of the membrane; mounting the membrane to a peripheral support structure whilst maintaining the tension in the membrane; assembling the mounted membrane with one or more other components to form an enclosure with the membrane forming one wall of the enclosure; and thereafter filling the enclosure with a fluid. The membrane may be formed from an aromatic polyurethane, and the fluid may be a phenylated siloxane. In some embodiments, the membrane is able to hold a substantially constant surface tension of at least 180 N/m for a period of at least 12 months.

Abstract: A deformable membrane assembly comprises an at least partially flexible fluid-filled envelope, one wall of which is formed by an elastic membrane that is held around its edge by a resiliently bendable supporting ring, a fixed support for the envelope and selectively operable means for causing relative movement between the supporting ring and the support for adjusting the pressure of the fluid in the envelope, thereby to cause the membrane to deform. The bending stiffness of the ring varies round the ring such that upon deformation of the membrane the ring bends variably to control the shape of the membrane to a predefined form. The moving means comprise a plurality of ring-engaging members that are arranged to apply a force to the ring at spaced control points.

Abstract: A method of fabricating a lens element for an adjustable power lens of the kind comprising two lens elements that are slidable relative to one other in a direction transverse the optical axis of the lens and have respective lens surfaces that are shaped to act together to form a corrective lens, the power of which varies according to the relative disposition of the two lens elements, the method comprising the steps of forming a lens puck having two opposite faces, which are shaped to form opposite lens surfaces of one of the lens elements of the adjustable power lens, the puck having at least one alignment feature, and thereafter edging the puck to a desired eye shape with reference to the alignment feature.

Abstract: A method of assembling an adjustable fluid-filled lens assembly comprising biaxially tensioning an elastomeric membrane to a surface tension of greater than 180 N/m, typically greater than 1000 N/m; thermally conditioning the tensioned membrane, e.g., for one hour at a temperature of about 80° C., to accelerate relaxation of the membrane; mounting the membrane to a peripheral support structure whilst maintaining the tension in the membrane; assembling the mounted membrane with one or more other components to form an enclosure with the membrane forming one wall of the enclosure; and thereafter filling the enclosure with a fluid. The membrane may be formed from an aromatic polyurethane, and the fluid may be a phenylated siloxane. In some embodiments, the membrane is able to hold a substantially constant surface tension of at least 180 N/m for a period of at least 12 months.

Abstract: An actuation mechanism for simultaneous actuation of first and second variable focal length lenses is disclosed. Each lens comprises a distensible membrane bounding a fluid-filled cavity, the focal length varying with the degree of curvature of the membrane as it distends. The actuation mechanism comprises a hydraulic master actuator in fluid communication with a hydraulic slave actuator associated with the first lens and with a hydraulic slave actuator associated with the second lens. Each slave actuator is configured to vary the degree of distension of the membrane of its associated lens in response to operation of the master actuator, whereby the master actuator is operable to cause a variation of the degree of distension of the membranes of both the first and second lenses simultaneously.

Abstract: An actuation mechanism for simultaneous actuation of first and second variable focal length lenses is disclosed. Each lens comprises a distensible membrane bounding a fluid-filled cavity, the focal length varying with the degree of curvature of the membrane as it distends. The actuation mechanism comprises a hydraulic master actuator in fluid communication with a hydraulic slave actuator associated with the first lens and with a hydraulic slave actuator associated with the second lens. Each slave actuator is configured to vary the degree of distension of the membrane of its associated lens in response to operation of the master actuator, whereby the master actuator is operable to cause a variation of the degree of distension of the membranes of both the first and second lenses simultaneously.

Abstract: The present invention provides a deformable membrane assembly 1 comprising an elastic membrane 8 that is held under tension around its edge by a bendable membrane supporting member 2,10, a body of fluid in contact with one face of the membrane, the pressure of the fluid being controllable for adjusting the shape of the membrane, and one or more bending controllers 24 acting on the supporting member 2, 10 to control the bending of the supporting member in response to loading through tension in the membrane. The bending stiffness of the membrane-supporting member 2, 10 varies round its extent to control the profile of the edge of the membrane 8; etc. upon actuation. A variety of different types of bending controllers are disclosed which permit out-of-plane bending of the supporting member 2, 10 but prevent or control in-plane bending or deformation of the supporting member.

Abstract: A deformable membrane assembly comprises an at least partially flexible fluid-filled envelope, one wall of which is formed by an elastic membrane that is held around its edge by a resiliently bendable supporting ring, a fixed support for the envelope and selectively operable means for causing relative movement between the supporting ring and the support for adjusting the pressure of the fluid in the envelope, thereby to cause the membrane to deform. The bending stiffness of the ring varies round the ring such that upon deformation of the membrane the ring bends variably to control the shape of the membrane to a predefined form. The moving means comprise a plurality of ring-engaging members that are arranged to apply a force to the ring at spaced control points.

Abstract: A deformable membrane assembly comprising a fluid-filled envelope, one wall of which is formed by an elastic membrane that is held around its edge by a bendable supporting ring, a support for the envelope and at least three ring-engaging members that are arranged to apply a force to the ring at spaced control points for adjusting the shape of the membrane, with the ring bending to control the shape of the membrane to a predefined form. A control point is provided at or proximate each point on the ring where the profile of the ring that is needed to produce the predefined form of the membrane exhibits a turning point in the direction of the force applied at the control point between two adjacent points where the profile of the ring exhibits an inflection point or a turning point in the opposite direction.

Abstract: A deformable membrane assembly comprises an at least partially flexible fluid-filled envelope, one wall of which is formed by an elastic membrane that is held around its edge by a resiliently bendable supporting ring, a fixed support for the envelope and selectively operable means for causing relative movement between the supporting ring and the support for adjusting the pressure of the fluid in the envelope, thereby to cause the membrane to deform. The bending stiffness of the ring varies round the ring such that upon deformation of the membrane the ring bends variably to control the shape of the membrane to a predefined form. The moving means comprise a plurality of ring-engaging members that are arranged to apply a force to the ring at spaced control points.