US-12625388-B2 - Glasses with selectively adjustable optical power lenses

US12625388B2US 12625388 B2US12625388 B2US 12625388B2US-12625388-B2

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.

Inventors

Robert Edward Stevens
Alex Edginton
Daniel Paul Rhodes
Martyn Francis Kenneally
Simon Peter Horrocks
Benjamin Ian Curnow

Assignees

ADLENS LTD

Dates

Publication Date: 20260512
Application Date: 20240513
Priority Date: 20160222

Claims (7)

1 . An adjustable power lens assembly comprising one or more frame parts, including a frame body, and an adjustable lens that is mounted to the frame body, the adjustable lens comprising two superposed lens elements, which define an optical axis, the lens elements being slidable relative to one another along an axis of sliding that is in a direction transverse the optical axis and comprising cooperating respective lens surfaces that are shaped to act together to form the adjustable lens, the power of which varies according to the relative disposition of the two lens elements; wherein at least one of the lens elements is mounted slidably to the frame body and comprises a plurality of guide formations that cooperate with corresponding formations on the frame body for guiding sliding movement of the at least one lens element relative to the other lens element along the axis of sliding, such that the position of the one lens element relative to the other lens element can be adjusted; wherein the plurality of guide formations comprise at least two tabs that protrude outwards from the periphery of the at least one lens element in the same direction as each other and the corresponding formations comprise one or more corresponding channels, the tabs and one or more corresponding channels configured and arranged to define a locus of movement of the at least one lens element relative to the frame body; and wherein at least one of the lens elements is mounted slidably to the frame body and is resiliently biased against the frame body in a direction orthogonal to the direction of sliding, thereby registering the lens element to a datum defined by the frame body.
2 . An adjustable power lens assembly as claimed in claim 1 , wherein the at least one lens element is resiliently biased against the frame body in a direction orthogonal to the direction of sliding and the optical axis.
3 . An adjustable power lens assembly as claimed in claim 1 , wherein the at least one lens element is resiliently biased by at least one spring positioned between a respective one of the guide formations and the frame body in a corresponding recess formed in the frame body.
4 . An adjustable power lens assembly as claimed in claim 1 , wherein at least one other tab protrudes from the periphery of the at least one lens element and is received in a corresponding channel formed in the frame body, said other tab being resiliently biased against the frame body in the direction of the at least two tabs for urging the lens element into positive alignment with the frame body.
5 . An adjustable power lens assembly as claimed in claim 4 , wherein the lens has a generally quadrilateral shape, having two opposite longer sides and two opposite shorter sides, wherein the at least one lens element is arranged to slide relative to the frame body in a direction generally parallel to the longer sides, the at least two tabs being positioned on one of the longer sides, and the other tab being positioned on the other longer side.
6 . A pair of glasses comprising at least one adjustable power lens assembly as claimed in claim 1 .
7 . An adjustable power lens assembly as claimed in claim 1 comprising a selectively operable optical power adjuster configured to control the position of the lens elements relative to each other in the direction transverse the optical axis of the lens.

Description

The present invention relates to glasses with selectively adjustable optical power lenses and has particular reference to glasses in which at least one of the lenses comprises two superposed lens elements and a selectively operable optical power adjuster, the lens elements being slidable relative to each other in a direction transverse the optical axis of the lens under the control of the optical power adjuster and having 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. Variable power lenses comprising two lens elements arranged in tandem, one behind the other along the optical axis of the lens, are disclosed in U.S. Pat. No. 3,305,294 (Alvarez), the contents of which are incorporated herein by reference. According to U.S. Pat. No. 3,305,294, each of the lens elements has polished surfaces, with one of the surfaces being a regular surface of revolution, and an optical thickness variation parallel to the optical axis less than one-half the lens diameter, the optical thickness t of each lens element parallel to the optical axis z being substantially defined by the formula: t=A⁡(x33+xy2)+Dx+E(I) wherein D is a constant representing the coefficient of a prism removed to minimise lens thickness and may be zero, E is a constant representing lens thickness at the optical axis, x and y represent coordinates on a rectangular coordinate system centred on the optical axis and lying in a plane perpendicular thereto, t is the optical thickness parallel to the optical axis and A is a constant representing the rate of lens power variation with lens movement in the x direction. It will be understood that the direction of movement in the x direction is positive for one lens element negative for the other lens element. Spectacles incorporating such variable power lenses are disclosed in U.S. Pat. No. 5,644,374 (Mukaiyama et al.), United States patent application publication no. US 2008/0030678 A1 (Koops et al.), United States patent application publication no. US 2009/0122254 A1 (Van der Heijde et al.) and international patent application publication no. WO 2013/030603 A1 (Gici Labs LLP). It is an object of the present invention to provide an improved pair of glasses comprising at least one selectively adjustable optical power lens of this kind. A different aspect of the invention provides an improved method of making adjustable lenses and lens elements for incorporation into such adjustable lenses. According to a first aspect of the present invention there is provided pair of glasses comprising two lenses and one or more frame parts; wherein one or both of the lenses is adjustable, comprising two superposed lens elements and a selectively operable optical power adjuster, the lens elements being slidable relative to each another in a direction transverse the optical axis of the lens under the control of the optical power adjuster and having 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; wherein the lens elements are configured and arranged such that upon increasing the optical power of the adjustable lens, the centration distance between the two lenses progressively decreases. Generally, in all of the various aspects of the present invention, the one or more frame parts may themselves be adapted for supporting the glasses on a user's face. In some embodiments, for example, the frame parts may comprise temple arms (or “temples”). However, in other embodiments the frame parts may be mounted to a head-band, a helmet, goggles or any other equipment or part for holding the frame parts, with the lenses, in front of the user's eyes. The or each adjustable lens defines an optical axis and its two lens elements are superposed one behind the other along the optical axis of the lens. The one or more frame parts typically comprise a nose-bridge, and suitably the lens elements are configured and arranged such that upon increasing the optical power of the adjustable lens, the mid-point of the two lens elements moves towards the nose-bridge. The or each adjustable lens may have an axis of relative movement between the lens elements that extends generally towards and away from the nose-bridge. When worn, the axis of relative movement may be oriented generally horizontally. Adopting the same coordinate system of mutually perpendicular axes x, y and z as described above in relation to formula (I) to define parameters of the lens, the optical axis of the lens may be taken to be the z axis, the axis of relative movement of the lens elements may be designated the x axis, while they axis may be designated perpendicular to the x axis and perpendicular to the optical axis z. When the glasses are worn, they axis will usually be oriented generally vertically. In a pair of glasses, the centration distan