# US 12,001,119 B2 · Flexible liquid crystal-containing lenses

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- Number: US 12,001,119 B2
- Document ID: US12001119B2
- Status: Granted
- Kind: B2
- Application number: 17/951,132
- Filed: 2022-09-23
- Published: 2023-04-20
- Granted: 2024-06-04
- Earliest claimed: 2021-10-19
- Assignees: CooperVision International Limited
- Applicants: CooperVision International Limited
- Inventors: Robert Oag; Roger Brian Minchin Clarke; Mikhail Bashtanov
- Web page: https://patentgrep.com/patent/US12001119B2

## CPC

- G02C 7/04: Contact lenses for the eyes (disinfection or sterilisation of contact lenses A61L12/00)
- G02F 1/294: {Variable focal length devices}
- G02B 1/043: {Contact lenses}
- G02C 7/041: {bifocal; multifocal}
- G02C 7/083: {Electrooptic lenses}
- G02C 2202/16: Laminated or compound lenses
- G02C 2202/20: Diffractive and Fresnel lenses or lens portions
- G02C: SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES (trial frames for testing the eyes A61B3/04; goggles or eyeshields not having the same features as spectacles A61F9/00)
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An electrically-switchable flexible contact lens for conforming to an eye of a user is provided. The lens comprises a liquid crystal cell for changing a focal power of the contact lens, and the liquid crystal cell has a cell gap thickness between a first inner surface and a second inner surface, the liquid crystal cell comprising a diffractive optical element for correcting the vision of a user, wherein the diffractive optical element is arranged to maintain the cell gap thickness by providing support at one or more locations within the cell.

## Claims

### Claim 1

An electrically-switchable flexible contact lens for conforming to an eye of a user, the lens comprising:
a first liquid crystal cell for changing a focal power of the contact lens, and having a cell gap thickness between a first inner surface and a second inner surface,
the first liquid crystal cell comprising a diffractive optical element for correcting the vision of a user,
wherein the diffractive optical element is arranged to maintain the cell gap thickness by providing support at one or more locations within the cell, and
the diffractive optical element comprises an inner portion and an outer portion, a maximum height of the diffractive optical element at the outer portion being greater than a maximum height of the diffractive optical element at the inner portion such that the diffractive optical element at the outer portion provides support to and spaces the first inner surface and the second inner surface at a greater distance at an outer region of the first liquid crystal cell than an inner region of the first liquid crystal cell.

### Claim 2 (depends on 1)

The electrically-switchable flexible contact lens of claim 1, further comprising a perimeter spacer provided at the perimeter of the first liquid crystal cell for maintaining the cell gap thickness in addition to the diffractive optical element.

### Claim 3 (depends on 1)

The electrically-switchable flexible contact lens of claim 1, wherein the first liquid crystal cell comprises a cholesteric liquid crystal, and the first liquid crystal cell is operable between a first, unswitched state and a second, switched state, wherein in one of the first and second states, the difference in the effective refractive index of the liquid crystal and the refractive index of the diffractive optical element is greater than in the other of the first and second states.

### Claim 4 (depends on 3)

The electrically-switchable flexible contact lens of claim 3, wherein in the other of the first and second states, the difference in the effective refractive index of the liquid crystal and the refractive index of the diffractive optical element is approximately nil.

### Claim 5 (depends on 1)

The electrically-switchable flexible contact lens of claim 1, wherein at least a portion of the diffractive optical element is attached to the first inner surface and at least a portion of the diffractive optical element may be attached to the second inner surface.

### Claim 6 (depends on 1)

The electrically-switchable flexible contact lens of claim 1, wherein at both 450 nm and 700 nm, the average refractive index of the liquid crystal is 0.80 to 1.20 times the refractive index of the diffractive optical element, the average refractive index being nave=0.5(ne+no), where ne is the extraordinary refractive index and no is the ordinary refractive index.

### Claim 7 (depends on 6)

The electrically-switchable flexible contact lens of claim 6, wherein at both 450 nm and 700 nm, said average refractive index of the liquid crystal is 0.95 to 1.05 times the refractive index of the diffractive optical element.

### Claim 8 (depends on 1)

The electrically-switchable flexible contact lens of claim 1 further comprising a second liquid crystal cell for changing a focal power of the contact lens, the second liquid crystal cell optionally comprising the features of the first liquid crystal cell.

### Claim 9 (depends on 1)

The electrically-switchable flexible contact lens of claim 1, wherein the maximum height of the diffractive optical element at the outer portion is from 1% to 20% greater than the maximum height of the diffractive optical element at the inner portion.

### Claim 10 (depends on 9)

The electrically-switchable flexible contact lens of claim 9, wherein the maximum height of the diffractive optical element at the outer portion is at least 3% greater and up to 15% greater than the maximum height of the diffractive optical element at the inner portion.

### Claim 11 (depends on 10)

The electrically-switchable flexible contact lens of claim 10, wherein the liquid crystal comprises a cholesteric liquid crystal, and optionally, in an unswitched state, a director of the liquid crystal may be at an angle of no more than 5 degrees to the first and second inner surfaces, and in a switched stated, a director of the liquid crystal may be at an angle of at least 60 degrees, optionally at least 70 degrees, optionally at least 80 degrees and optionally at least 85 degrees to the first and second inner surfaces.

### Claim 12 (depends on 9)

The electrically-switchable flexible contact lens of claim 9, wherein the diffractive optical element comprises a plurality of peaks and troughs, and the outer portion comprises an outer peak, optionally the outermost peak.

### Claim 13 (depends on 9)

The electrically-switchable flexible contact lens of claim 9, wherein the diffractive optical element extends over a chord length, r, the inner portion comprises the portion of diffractive optical element within a cord length of r/8 from a centre of the diffractive optical element, and the outer portion comprises the portion of diffractive optical element having a chord length of from 3 r/8 to r/2.