CN101194198A - Adaptive electro-active lens with variable focal length - Google Patents

Abstract

An adjustable focusing electrically controllable electroactive lens is provided. The adjustable focusing electrically controllable electroactive lens can adjust the focal length discretely or continuously. The lens can be incorporated in a variety of optical devices including spectacles.

Description

Adaptive electro-active lens with variable focal length

Cross-references to related applications

This application claims priority to US Provisional Application No. 60/645839, filed January 21, 2005, which is hereby incorporated by reference in its entirety.

Background technique

Correction of age-related optical changes in the eye is becoming increasingly important as life expectancy continues to increase. One age-related optical change of the eye is presbyopia, in which it is difficult to focus on close objects on the retina due to reduced flexion of the lens. Presbyopia usually begins to affect people in their forties, so vision correction is very much needed. Lenses with fixed focusing properties have been widely used as eyeglasses and contact lenses to correct presbyopia and other conditions.

These lenses are most useful if they have adjustable focusing power (ie, the focusing power is not fixed). An adjustable focus magnification provides the eye with external accommodation to bring objects of interest at different distances into focus. Adjustable focus magnification can be achieved using a mechanical zoom lens. However, mechanical methods make the glasses bulky and expensive.

Different optical technologies have been utilized in bifocal lenses to allow both near and distance vision. For example, a user may wear lenses that provide different focusing powers for each eye, one lens for close objects and the other lens for distant objects. Alternatively, by utilizing zoning of lenses, bifocal diffractive lenses, or other partitioning techniques, near and distant objects are simultaneously imaged onto the retina, and the brain differentiates the images. With the exception of bifocal diffractive lenses, the fields of view utilizing these optical techniques are small. Also, these optical techniques don't work well when the pupil is small because the iris blocks the beam of light passing through the annular portion of the lens. Another option for correction is to use a monovision lens, where each eye is given a different focusing power, one for near objects and the other for distant objects. However, binocular depth perception is affected when monovision lenses are used.

Electrically switchable lenses (e.g., lenses with a layer of liquid crystal sandwiched between two conductive plates in which the orientation of the liquid crystal changes upon application of an electric field) for use in optical systems have been described (see, for example, Kowel, Appl. . Opt. 23(16), 2774-2777 (1984); Dance, Laser Focus World 28, 34 (1992)). In electrically switchable lenses, various configurations have been investigated, including Fresnel zone plate electrode structures (Williams, SPIE Current Developments in Optical Engineering and Commercial Optics, 1168, 352-357 (1989); McOwan , Optics Communications 103, 189-193 (1993)). A variable focal length liquid crystal lens has been described (Sato, Jap. J. Appl. Phys. 24(8), L626-L628 (1985)). However, the use of liquid crystal lenses in ophthalmic lens applications is limited by a number of factors including very low diffraction efficiency when the focal length is changed and slow switching times due to the required thickness of the liquid crystal layer. There is a need for an improved lens with adjustable focus power.

Contents of the invention

Provided are a novel lens design and a corresponding device and method for adjusting the focal length of the lens. This new design is based on individually addressable electrode patterns. Described here are two applications of this new design. The first application is to allow the focal length to be switched between discrete values. In one embodiment, the focal length is switched between the initial focal length and an integer multiple of the initial focal length. The second application allows for a more general use where the focal length is continuously adjusted from the smallest possible value to infinity according to design parameters. This new design overcomes the difficulties described above.

More specifically, an electrically controllable electroactive lens with adjustable focus is provided. Methods for discontinuously or continuously adjusting an electrically controllable electro-active lens are also provided. Electrically controllable electro-active lenses allow adjustment of focus without cumbersome and ineffective mechanical movements. Compared with simultaneous vision lenses such as bifocals, trifocals, and monocular vision lenses, the focus power is adjusted by electro-activation and the entire aperture has the same focus power under each operating condition. Or progressive or contact lenses, where the field of view for each line of sight is limited to a narrow channel and the user is faced with two images, in which binocular depth perception is affected. Devices made from adjustable-focus, electrically controllable lenses provide adjustable focus with large fields of view and high image quality without the need to switch between different physical lenses. Other advantages of the lens include compactness, lower weight, lower cost and easier operation with low voltage and power loss.

In one embodiment, an adjustable focus, electrically controllable electro-active lens is provided, the electro-active lens comprising: a liquid crystal layer positioned between a pair of transparent substrates; a Fresnel zone having M regions a Fresnel zone patterned electrode, each zone having L individually addressable sub-zones between the liquid crystal layer and the inwardly facing surface of the first transparent substrate, where M and L are positive integers; and A conductive layer between the liquid crystal layer and the inwardly facing surface of the second transparent substrate. The individually addressable sub-regions of the patterned electrode of the Fresnel zone can be located on the same level, wherein the sub-regions are separated by an insulator to prevent electrical shorting, or the Fresnel zone can be individually addressable by the patterned electrode. The addressed sub-regions may lie on two or more levels, each separated by an insulating layer, or other configurations may be used as known in the art.

A method for adjusting the focal length of a lens to an integer multiple of the initial focal length F is provided, the method comprising: providing a lens, the lens comprising: a lens of a liquid crystal layer sealed between a pair of transparent substrates; a lens located between the liquid crystal layer and the first The Fresnel zone between the inwardly facing surfaces of the transparent substrate is patterned with M regions each having L subregions, the patterned electrode having a total of M·L individually addressable addressable electrodes; a conductive layer between the liquid crystal layer and the inwardly facing surface of the second transparent substrate; and an electrical control device electrically connected to the electrode region and the conductive layer; applying the same to every k individually addressable electrodes voltage, thereby adjusting the focal length to kF, where k is an integer from 1 to ML. The focal length can be adjusted from F to infinity discontinuously.

A method of continuously adjusting the focal length of a lens is provided, the method comprising: (a) providing a lens comprising a liquid crystal layer sealed between a pair of transparent substrates; a Fresnel region patterned electrode having a L diffraction orders between the liquid crystal layer and the inwardly facing surface of the first transparent substrate, the patterned electrode being a circular array of individually addressable rings; the inwardly facing surface of the liquid crystal layer and the second transparent substrate The conductive layer between the surfaces; and the electrical control means electrically connected to the electrode area and the conductive layer; (b) determine the desired focal length (f'); (c) use the equation: r _m ² +f' ² =( f′+mλ) ² to calculate the area of the mth region of the patterned electrode in the Fresnel zone, where f′ is the design focal length, λ is the design wavelength, and r _m is the radius of the mth subregion; (d) use An integer of L or greater divides the calculated area of the mth region to determine the number of individually addressable electrodes forming the design subregion; (e) to these numbers of individually addressable electrodes in the design subregion The same voltage is applied to the electrodes. This method for continuously adjusting the focal length also includes, prior to step (a): determining one or more design focal lengths; calculating the maximum ring size in the patterned electrode in the Fresnel zone, which allows the maximum ring size in the design sub-region Form all design focal lengths.

In one embodiment, the electrode regions are formed by patterned ITO (Indium Tin Oxide) electrodes. The phase retardation in each region is modulated by redirecting the liquid crystals with an applied electric field, as is known in the art.

The adjustable focus, electrically controllable electro-active lenses described herein offer a number of advantages over current approaches. One advantage resides in the ability to adjustably change the focus power of the lens. The focal length of the diffractive lens is determined by the electrode area spacing. In the lenses described here, the electrode pattern is fixed and the focal length can be changed directly by changing the electrical drive connections to the electrodes and the applied voltage. In one embodiment, individually addressable electrode regions allow for correction of vision at different distances, including near (eg, reading), intermediate distance (eg, computer screen), and distance vision. The focus magnification can be adjusted directly by the rangefinder or manually by the user. In one embodiment, tiny electronic circuits are integrated with the lens so that the assembly is compact. Also, the electrode structure is not visible, which provides a decorative advantage over flat liquid crystal solutions. The loss of electrical power does not affect distance vision (focusing magnification provided when no current is supplied). The entire aperture has the same focus magnification under each operating condition. The Fresnel zone structure described herein in one embodiment allows for relatively large apertures, which are required for lens applications. Other advantages of the invention described here include compact design, lighter weight, lower cost, and easier operation with low voltage and low power dissipation.

As is known in the art, the focal length and corresponding diopter values of the lenses described herein can be positive or negative depending on the applied voltage. Such variations would be known to one of ordinary skill in the art without undue experimentation, and are included herein.

As used herein, "adjustable focus" means that the focal length of the lens is not fixed at a distance as in conventional optical lenses. The focal length of the adjustable focusing lens is adjusted by varying the voltage applied to the electrodes by means known in the art. In one embodiment, the user adjusts the focus to see objects at the desired distance. "Individually addressable" means capable of independently applying the same or different voltages to different electrodes. "Electrically controllable" means applying a voltage to control or change a parameter, such as changing the orientation state of liquid crystals, as is known in the art. "Continuously adjustable" means that the focal length can be adjusted to many different values that are not exact multiples of the original focal length, and due to the physical limitations of current patterned electrode fabrication techniques, "continuously adjustable" does not necessarily mean that every Different focal lengths are available.

As used herein, a "layer" does not require to be a completely uniform film. Some thickness unevenness, cracks, or other defects may be present, so long as the layer serves its intended purpose, as described herein. As used herein, "perpendicular" means substantially perpendicular to the surface of the substrate. Note that the optical axis is generally approximately perpendicular to the surface of the substrate. As used herein, "no horizontal gap" between electrodes includes a situation in which there is no space between electrodes when viewed in a vertical direction, and also includes a situation in which there is a space between electrodes when viewed in a vertical direction but its Conditions, and all values and ranges therein, that do not reduce the diffraction efficiency of the optical instrument by more than 25% from the theoretical maximum.

The devices of the present invention may be used in a variety of applications known in the art, including lenses for vision correction or modification in humans or animals. These lenses can be incorporated into eyeglasses as is known in the art. Eyeglasses may include one lens or more than one lens. These devices may also be used in display applications, as would be known to one of ordinary skill in the art without undue experimentation. The lenses of the present invention can also be used with conventional lenses and optical systems. The lenses of the present invention may be used as part of conventional lenses, for example inserted into conventional lenses, or combinations of conventional lenses and lenses of the present invention may be used in a stacked fashion.

The invention is useful in the preparation of spectacles having lenses that adjust the focus strength according to the distance from the object being viewed. In one embodiment, the ranging mechanism, battery and control circuitry are housed in the glasses or are part of a separate control system. These components and their use are well known in the art. As an example, a range finding mechanism is used to determine the distance between the glasses and a desired object. This information is fed to a microprocessor which adjusts the voltage applied to the individually addressable electrodes, which provides the desired phase transfer function to the lens to view the object.

Various methods of applying voltage to the electrodes can be used, as is known in the art. A battery may be used to supply the voltage, or other methods may be used, as is known in the art. Various methods of controlling all aspects of the voltage applied to the electrodes are known in the art, including processors, microprocessors, integrated circuits, and computer chips. The applied voltage is determined by the desired phase transfer function, as is known in the art.

Description of drawings

Figure 1 shows a diagrammatic illustration of a diffractive lens: graph (a) is a conventional refractive lens; graph (b) is a diffractive lens with a continuous secondary blaze profile; graph (c) is a binary diffractive lens; Diagram (d) is a fourth-order approximation for a diffractive lens.

Fig. 2 shows the structure of a diffractive lens.

Fig. 3 shows a liquid crystal cell.

Figure 4 shows the general structure of an electro-active liquid crystal lens with patterned electrodes.

Figure 5A shows a structure in which all electrodes lie on the same plane (single layer structure) with small gaps between adjacent sub-regions.

FIG. 5B shows a structure in which odd-numbered electrodes and even-numbered electrodes are interleaved in two horizontal layers without gaps between adjacent sub-regions (two-layer structure).

Figure 6 shows an example of digital variable focus using individually addressable electrode patterns.

Figure 7 illustrates continuous adjustment of the focus using an individually addressable circular array of electrodes with appropriate resolution.

Detailed ways

In order to better understand the present invention, here is a brief review of the basic concepts of liquid crystal cells, some basic concepts of diffractive lenses and the principle of adaptive lenses.

diffractive lens

Diffractive lenses are well known in the art. The function of diffractive lenses is based on near-field diffraction of Fresnel zone patterns. Every point emanating from the structure acts as a spherical wave emitter. The light field at a particular observation point is the sum of the contributions of the emitted spherical waves to the entire structure. The constructive interference of spherical waves from various points produces a high intensity at the observation point, which corresponds to high diffraction efficiency.

Figure 1 shows a diagrammatic illustration of a diffractive lens: graph (a) is a conventional refractive lens; graph (b) is a diffractive lens with a continuous secondary notch profile; graph (c) is a binary diffractive lens; graph (d) ) is the fourth-order approximation of the diffractive lens.

Diagram (a) of FIG. 1 shows a part of a conventional refractive lens. By removing the phase retardation of multiples of 2[pi] of the refractive lens, a diffractive lens as shown in diagram (b) of Fig. 1 is obtained. The phase jump at the boundary of each region is 2π for the design wavelength _λ0 , and the notch profiles in each region form perfect constructive interference at the focal point. Graph (c) of Figure 1 and graph (d) of Figure 1 show different approximations to the desired phase profile in Figure 1(b), where multiple steps in each region are used to approximate the desired phase profile.

Fig. 2 shows the structure of a diffractive lens. Shows the focal length (f) along the optical axis. The radius (r _m ) perpendicular to the optical axis is shown. Note that light entering a lens of radius ( _rm ) to reach the focal point F takes a path equal to the focal length (f) plus an integer number of wavelengths (mλ) in order to have constructive interference.

In other words, the focal length (f) of the diffractive lens is determined by the period of these regions. The difference in optical path length is a multiple of the wavelength. For the mth region, note that f+mλ is the hypotenuse of the right triangle in Figure 2:

${\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="S2006800092632E00071.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="f"\; filenames="S2006800092632E00071.png"\; state="\{\{state\}\}">f</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; m\&lambda;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

For the paraxial approximation, f>>mλ, the radii (r) of these regions or region boundaries are given by

${\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="S2006800092632E00071.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m\&lambda;f</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; )</span>$

where _rm is the outer diameter of the mth (m=1, 2...M) region, λ is the wavelength, and f is the focal length. For an L-level diffractive lens, each region is composed of L subregions of equal size (area). Note that there are L subregions, and each subregion has a different optical thickness, and therefore, has L phase levels.

The outer diameter of the nth subarea (n = 1, 2, 3...L, where L is the number of phase levels in each area) of the mth area is given by

${\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; ]</span>\mathrm{<span\; class="notranslate">\; \&lambda;\; f</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; )</span>$

This determines the Fresnel zone pattern, which is periodic at ^r2 . This period is equal to r ₁ ² . Note that _r1 is the radius of the first region, and each region has the same area. The focal length of the diffractive lens is

$\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="r"\; filenames="S2006800092632E00011.png,S2006800092632E00061.png"\; state="\{\{state\}\}">r</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

The above equation means that the focal length can be changed by selecting the zone period. For a lens with focal length p·f, the size (area) of each region is p·r ₁ ² .

The diffraction efficiency of a multi-level diffractive lens (or L-phase grade diffractive lens) is given by

$\mathrm{<span\; class="notranslate">\; \&eta;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; c</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Table 1 gives the parameters of the 1-diopter diffractive lens. As shown in Table 1, the diffraction efficiency increases as the number of phase levels increases, while the width of the last sub-region decreases as the aperture of the lens increases.

Table 1

phase level Diffraction efficiency Width of the last subregion in μm 10mm aperture lens 20mm aperture lens 2 40.5% 56 28 4 81.1% 28 14 6 91.2% 19 9 8 95.0% 14 7 16 98.7% 7 3.5

LCD unit

Liquid crystal cells are well known in the art. Many cell configurations and operations for liquid crystal cells are also known in the art.

Figure 3 shows a diagrammatic embodiment of an electro-active liquid crystal cell in which a liquid crystal layer is sandwiched between two glass plates with conductive inner surfaces. The surfaces of the two plates are coated with an alignment layer such as polyvinyl alcohol (PVA) or nylon 6,6, and these surfaces are treated by rubbing to give uniform molecular orientation. The alignment layer is polished in the direction indicated by the arrows, as known in the art. A voltage is applied to the conductive inner surface of the plate. In an electro-active cell using liquid crystals as the electro-optic medium, each region has the same thickness, but when a voltage is applied to the medium, the refractive index of the extraordinary beam changes due to the reorientation of the liquid crystal molecules. As shown in FIG. 3, the polishing direction determines the initial orientation of the liquid crystal molecules. The long axes (optical axes) of the liquid crystal molecules are vertically aligned. When an appropriate voltage is applied, the molecules rotate. The effective refractive index (n _θ ′) is given by

${\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}{\sqrt{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="e"\; filenames="S2006800092632E00071.png"\; state="\{\{state\}\}">e</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="sin"\; filenames="S2006800092632E00071.png"\; state="\{\{state\}\}">sin</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="o"\; filenames="S2006800092632E00071.png"\; state="\{\{state\}\}">o</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="cos"\; filenames="S2006800092632E00071.png"\; state="\{\{state\}\}">cos</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

where n _o and n _e are the refractive indices of ordinary and extraordinary beams, respectively, and θ is the angle between the optical axis of the molecule and the vertical axis. An extraordinary beam initially has a maximum refractive index n _θ . As the applied voltage increases, the effective refractive index _nθ ' becomes smaller, and when the saturation voltage is applied, the optical axes of the molecules are aligned horizontally, while the effective refractive index _nθ ' reaches a minimum and is equal to n _o . The refractive index of an ordinary beam (horizontally polarized) is always the same. Thus, the electro-optic effect modulates the effective refractive index of the extraordinary beam.

In the liquid crystal cell described herein, the conductive material on one substrate does not form a uniform layer, but instead forms a pattern of electrodes, as further described herein.

Figure 4 shows the general structure of an electro-active liquid crystal lens with patterned electrodes. From top to bottom, the layers include:

410 substrate,

420 patterned electrodes (individually controllable electrodes),

430 alignment layer,

440 liquid crystal and 450 spacer (or spacers),

430 alignment layer,

460 ground, and

410 substrate.

In particular, Figure 4 shows the general structure of the electro-active liquid crystal lens used here. The liquid crystal layer 430 is sandwiched between the patterned electrode 420 and the ground electrode 460 . The patterned electrode 430 can be fabricated by photolithographic processing of a conductive film deposited on a glass substrate, as is known in the art, and the ground electrode 460 comprises a uniform conductive film formed in any manner known in the art. layer. These patterned electrodes comprise circular arrays of rings whose radii are determined by the desired focal length, as described herein. The electro-optic effect of liquid crystal 440 results in electrically controllable birefringence. The phase profile across the lens is altered by applying appropriate voltages to the patterned electrodes, as further described herein.

The conductive material may be any suitable material, including those specifically described herein as well as others known in the art. Preferably, the conductive material is transparent, such as indium oxide, tin oxide or indium tin oxide (ITO). The substrate can be any material, such as quartz, glass or plastic, that can provide the desired optical transmission and that can function in the devices and methods described herein, as is known in the art. The thickness of the conductive layer is typically between 30nm and 200nm. This layer must be thick enough to provide adequate conduction, but not so thick as to provide excessive thickness to the overall lens structure. Patterned electrodes 420 may be formed using photolithographic techniques, such as described herein and known to those of ordinary skill in the art.

FIG. 5A shows a structure in which all electrodes are on the same plane (single layer structure) with small gaps between adjacent sub-regions. The controller or driver 510 is connected by wires 520 to vias or contacts 530 which in turn are connected to individually controllable electrodes 540 . Note that the wires 520 can be electrically insulated from the electrodes 540 by an insulating layer (not shown), and then selectively contacted to the electrodes by vias (holes or channels in the insulating layer) or contacts 530 . This type of contact fabrication is well known in fabrication lithography as well as in integrated circuit fabrication.

More specifically, Figure 5A shows a concentric, individually addressable (individually controllable) ring-shaped electrode layout in one layer. Ignoring the wires 520 and the vias through the insulation, this layout is defined as a "single layer" structure because all electrodes are in a single layer.

Alternatively, the wires 520 may be closely packed in a bus (not shown) that moves radially relative to the concentric ring electrodes.

Note that other patterned electrode shapes can be utilized. For example, a hexagonal array could contain hexagonal pixels, or a grid array could contain square pixels, or an irregularly shaped collection could correct for asymmetrical refractive errors. Irregularly or complexly shaped electrodes can be fabricated to correct characteristic asymmetric or unconventional or higher order refractive errors. In addition, these electrodes may have a variable thickness along the optical axis in order to form a more complex interaction with the liquid crystal.

Alternately, especially if more than two pixels fit within the width of one ring electrode, arrays with high pixel density can be manipulated to approximate the concentric rings of Figure 5A to form a diffractive lens. Such high-pixel-density arrays can also approximate more complex shapes.

Returning to Figure 5A, the innermost ring electrode is defined as the electrode numbered 1, counting outward to the 16th outermost electrode. Note that the innermost electrode may preferably be a full circle rather than a ring, but Figure 5A shows a symmetrical ring and to more clearly show the via or contact 530 with the innermost ring electrode.

To form a 4-stage or 4-phase diffractive lens, the innermost four rings are combined into one region. This first region includes electrodes 1-4, numbered from the innermost electrode outwards. Each of these electrodes 1-4 is a sub-area of the first area. The second area includes electrodes 5-8. The third area includes electrodes 9-12. The fourth area includes electrodes 13-16. This combination of 16 electrodes produces a 4-order (or phase) diffractive lens with 4 regions.

As discussed above, each ring electrode 540 is independently addressable by wire 520 . If all electrodes are distributed in one layer, there must be electrically insulating gaps between adjacent electrodes. Gaps between electrodes can cause phase distortion, and simulations of this design show that this phase distortion can greatly affect diffraction efficiency and other performance measures.

To mitigate distortions caused by insulating gaps between electrodes in a single layer design, other electrode configurations may be used. For example, the ring electrode can be separated into two distinct layers to form a "double layer" design.

In particular, odd-numbered rings may be located in one electrode layer, while even-numbered rings may be located in a second, separate electrode layer. These two different electrode layers can be separated by an insulating layer such as _SiO2 .

FIG. 5B shows a structure in which odd-numbered electrodes and even-numbered electrodes are interleaved in two horizontal layers without gaps between adjacent sub-regions (two-layer structure).

A controller or driver 510 is delivered to these electrodes by wires 520 and the electrodes are combined into a layer 542 with even rings and a layer 544 with odd rings. The two electrode layers are separated by an insulating layer SiO ₂ 544 . Chromium (Cr) alignment marks 560 are also shown for lithographic fabrication alignment. Also shown are region m 580 and region m+1 590, which correspond to the contiguous regions of FIG. 5A.

In Fig. 5B, a cross-section of a double-layer electrode pattern is shown, where odd-numbered and even-numbered rings are distributed in two separate layers when viewed in the vertical direction (viewed along the optical axis), and in There is no gap between two adjacent electrodes. In particular, note that region m 580 extends from _rm to rm ₊₁ and includes a total of 4 electrodes. Two of the 4 electrodes in region m 580 are even numbered electrodes and are located in layer 542 , while the remaining 2 electrodes in region m 580 are located in layer 544 .

In this case, each ring electrode 540 can be individually addressed via a via from an additional layer (not shown in FIG. 5B ), as in the single layer case. Conductors 520 may be located in any convenient location or layer.

The following is an example of forming a bilayer structure. Alignment marks 560 are deposited on the conductive layer for the substrate on which the patterned electrodes are to be applied. Any suitable material can be used for the alignment marks, such as chrome (Cr). Alignment marks 560 allow the various photolithographic masks to be properly aligned with the substrate, and thus allow for the alignment of the patterns formed in the processing steps associated with each mask using the "mask set" , the "mask set" is fabricated to have the desired overall lithographic definition of the electrode when it is patterned. A portion of the area of the electrode being patterned is formed in the conductive layer using methods known in the art and described herein. A layer of insulator such as SiO2 ₅₅₀ is deposited onto the patterned conductor layer. A second layer conductor is deposited onto the _SiO2 and a second portion of the patterned electrode region is formed in the second layer conductor.

An alignment layer (not shown) is placed on the second layer of conductors and over the conductors of the second substrate. The alignment layer is prepared by methods known in the art, such as by unidirectional rubbing. Alignment layers currently used are spin-coated polyvinyl alcohol or nylon 6,6. Preferably, the alignment layer on one substrate is rubbed antiparallel to the alignment layer on the other substrate. This provides proper alignment of the liquid crystals, as is known in the art. A layer of liquid crystal is placed between the substrates, and the substrates are separated by a desired distance (such as between 3 microns and 20 microns apart) with glass spacers, or in other ways known in the art. Bottom separated. The spacers may be any desired material, such as mylar, glass or quartz, or other materials useful to provide the desired spacing. For efficient diffraction, the liquid crystal layer must be thick enough to provide an activated retardation of one wavelength (d > λ/δn ~ 2.5 μm, where δn is the birefringence of the liquid crystal medium), but thicker liquid crystal layers help avoid saturation phenomenon. Disadvantages of thicker cells include long switching times (proportional to ^d2 ) and loss of electrical activation feature definition. The transparent substrates can be separated by any distance, which allows a desired number of patterned electrodes and a desired thickness of the liquid crystal layer. In certain embodiments, the transparent substrates are separated by between 3 microns and 20 microns, and all values and ranges therein. A presently preferred spacing is 5 microns.

In operation, a voltage is applied to the electrodes by the controller to change the refractive index to the desired degree. A "controller" may include, or be included in, a processor, microprocessor, integrated circuit, IC, computer chip and/or chip. Typically, voltages up to about 2Vrms are applied to the electrodes. Phase synchronous, waveform controlled drivers are connected to each electrode set in a common ground configuration. Multiple driver amplitudes are simultaneously optimized for maximum focusing diffraction efficiency. The voltage function required to change the refractive index to the desired degree is determined by the liquid crystal or mixture of liquid crystals used, as is known in the art.

Figure 6 shows an example of digital variable focus using individually addressable electrode patterns. Graph (a) corresponds to the fundamental focal length F determined by the area of the initial single electrode (ie, the period of the initial structure). The period of the structure is the area of the initial single electrode. The focal length can be increased to a multiple of F by increasing the period of the lens without affecting the diffraction efficiency. Graph (b) corresponds to a focal length of 2F. Each area (sub-area) of FIG. 6B is twice the area of the corresponding area in FIG. 6A. In both cases, the diffraction efficiency is the same.

In a particular embodiment, the voltages applied to the four electrodes of a particular 4-phase grade lens are 1.1V, 1.31V, 1.49V and 1.72V, respectively. In another example, the voltages applied to the eight electrodes of a special 8-phase grade lens are 0.71V, 0.97V, 1.05V, 1.13V, 1.21V, 1.30V, 1.37V, and 1.48V, respectively. The voltage applied to the electrodes can be readily determined by one of ordinary skill in the art without undue experimentation, and is a function of the liquid crystal used, the arrangement of the cells, and other factors, as known in the art . As noted above, these voltages can be positive or negative, depending on the desired focal length, as is known in the art. In one embodiment, the voltage applied to the electrodes is a positive or negative value between 0.5V and 2V, and all individual values and subranges therein.

The insulating material may be any suitable material, including those specifically described herein as well as others known in the art. In one embodiment, the conductive material and the insulating material are arranged in an alternating pattern, for example in a plurality of circles of increasing radius. The pattern can be any desired pattern, such as circular, semicircular, square, angular, or any other shape that provides the desired effect, as described herein. The terms "circle, semicircle, square, angle" and other shapes are not intended to denote the exact shape formed, but rather, the shape is a generally formed shape and may include bus lines as known in the art or through a substrate. Other ways to generate current at the bottom.

Any liquid crystal can be used in the present invention. Preferably, the switching time is fast enough that the user is not aware of the delay in switching from one focal length to another. In certain embodiments described herein, nematic liquid crystals are used as the electro-optic medium. In this embodiment, the lens responds to one of two orthogonally polarized components of light. Polarization-insensitive cholesteric liquid crystals can also be used, in which case polarizers are unnecessary. Liquid crystals used in the present invention include those forming nematic, smectic, or cholesteric phases possessing long-range alignment order that can be controlled with an electric field. Preferably, the liquid crystal has a wide nematic temperature range, easy alignment, low threshold voltage, large electrical excitation response and fast switching speed, and has proven stability and reliable industrial usability. In a preferred embodiment, E7 (nematic liquid crystal mixture of cyanodiphenyls and cyanoterphenyls sold by Merck) is used. Examples of other nematic liquid crystals that can be used in the present invention are: pentylcyanobiphenyl (5CB), (n-n-octyloxy)-4-cyanobiphenyl (80CB). Other examples of liquid crystals that can be used in the present invention are: compounds 4-cyano-4-n-alkyldiphenyl, 4-n-pentane Oxydiphenyl, 4-cyano-4″-n-alkyl-p-terphenyl, and commercial mixtures such as E36, E46, and ZLI series manufactured by BDH (British Drug House)-Merck.

Electroactive polymers may also be used in the present invention. Electroactive polymers include any transparent optically polymeric material, such as those disclosed by J.E. Mark in "Physical Properties of Polymers Handbook (Physical Properties of Polymers Handbook)" (American Institute of Physics, Woodbury, N.Y., 1996), which Materials comprising molecules with asymmetrically polarized conjugation of π electrons between an electron-donating atomic group and an electron-accepting group (called a chromophore), such as Ch. Bosshard et al. in Organic Nonlinear Optical Materials )" (Gordon and Breach Publishers, Amsterdam, 1995). Examples of polymers are the following: polystyrene, polycarbonate, polymethylmethacrylate, polyvinylcarbazole, polyimide, polysilane. Examples of chromophores are: p-Nitroaniline (PNA), Red Dispersant 1 (DR1), 4-methoxy-3-methyl-4'-nitrostilbene, diethylaminonitrodi Styrene (DANS, diethylaminonitrostilbene), diethylthiobarbituric acid. Electroactive polymers can be generated by a) following a client/host protocol, b) by covalent incorporation of chromophores into the polymer (suspension and backbone), and/or c) by methods such as crosslinking Lattice hardening methods, as known in the art.

Polymer liquid crystals (PLC) can also be used in the present invention. Polymer liquid crystals are also sometimes referred to as liquid crystal polymers, low molecular weight liquid crystals, self-reinforced polymers, in situ composites, and/or molecular composites. PLCs are copolymers that contain both relatively fixed and flexible sequences, such as "Liquid Crystalline Polymers: From Structures to Applications" by W. Brostow, edited by A.A. Collyer (Elsevier, New York-London, 1992, Chapter 1). Examples of PLCs are: polymethacrylates including pendant 4-benzonitrile benzoate groups and other similar compounds.

Polymer dispersed liquid crystals (PDLCs) can also be used in the present invention. PDLC consists of liquid crystal droplets dispersed in a polymeric matrix. These materials can be made in several ways: (i) by nematic curve aligned phase (NCAP), by thermally induced phase separation (TIPS), solvent induced phase separation (SIPS), and polymerization-induced Phase separation (PIPS), as known in the art. Examples of PDLC are: a mixture of liquid crystals E7 (BDH-Merck) and NOA65 (Norland products company, NJ); a mixture of E44 (BDH-Merck) and polymethylmethacrylate (PMMA); E49 (BDH-Merck) and A mixture of PMMA; a mixture of the monomer dipentaery throl-hydroxy-penta-acrylate, liquid crystal E7, N-vinylpyrrolidone, N-phenylglycine, and the dye rose bengal.

Polymer stabilized liquid crystals (PSLCs) can also be used in the present invention. PSLC is a material composed of liquid crystals in a polymer network, where the polymer constitutes less than 10% by weight of the liquid crystal. Photopolymerizable monomers are mixed with liquid crystals and UV polymerization initiators. After aligning the liquid crystals, polymerization of the monomers is usually initiated by UV exposure, and the resulting polymer forms a network that stabilizes the liquid crystals. For examples of PSLCs see, e.g., "Optical Studies of Anisotropic Networks in Polymer-Stabilized Liquid Crystals" by C.M.Hudson et al. (Journal of the Society for Information Display , vol.5/3, 1-5, (1997)), "Photorefractivity in Polymer-Stabilized Nematic Liquid Crystals (photorefractive index in polymer-stabilized nematic liquid crystals)" (J. of Am. Chem. Soc., 120, 3231-3236 (1998)).

Self-assembled nonlinear supramolecular structures can also be used in the present invention. Self-assembled nonlinear supramolecular structures including electrically activated asymmetric organic thin films can be fabricated using the following methods: Langmuir-Blodgett thin films, alternating polyelectrolyte deposition (polyanion/polycation) from aqueous solution, molecular beam epitaxy method, sequential synthesis via covalent coupling reactions (eg: multilayer deposition based on self-assembly of organotrichlorosilanes). These techniques generally result in films with a thickness of less than about 1 μm.

Although the non-limiting description herein provides more details of specific exemplary embodiments, different lens and electrode configurations may be used for various applications. For example, the lens can be immersed in a liquid crystal solution, or the liquid crystal can be sandwiched between planar electrode plates with gradient refractive index changes. The latter makes liquid crystal alignment easier and makes the cells thinner, which enables faster switching. Additionally, different electrode region configurations can be used in the methods and devices of the present invention. These various lens and electrode region configurations as known in the art are intended to be included in this disclosure.

New design with individually addressable patterned electrodes

To overcome the limitations of previous designs, each electrode sub-region of a patterned electrode must be individually addressed. Two different exemplary applications are presented here. One application allows switching between the base focal length and multiples of the base focal length. Another application is more general and allows continuous adjustment of the focal length from the smallest possible value to infinity.

1: Discontinuous adjustment of focal length

Consider the general structure of the liquid crystal lens shown in FIG. 3, and consider the electrode pattern shown in FIG. 5A or FIG. 5B. The phase profile on the lens is tuned by applying appropriate voltages to the patterned electrodes and determines the diffraction efficiency.

Individual addressing of sub-areas of the patterned electrode increases the area period, and thus the focal length, without loss of diffraction efficiency. It is assumed that the geometry of the electrode pattern is designed for phase modulation with L phase levels. According to equations (2a), (2b) and (3), if the region period r ₁ ² is increased to 2r by combining every two adjacent sub-regions into one, i.e. applying the same voltage to two adjacent electrodes ₁ ² , then the focal length becomes 2F without changing the diffraction efficiency (Fig. 6). Similarly, with a fixed electrode pattern, the focal length can be changed to 3F, 4F, ... by increasing the field period to 3r ₁ ² , 4r ₁ ² , ... respectively. In general, the focal length can be changed to kF (k is a positive integer) by increasing the field period to kr ₁ ² .

If an individually addressable electrode pattern is designed for an adaptive lens with a base focus power of eg 3 diopters (focal length F=33.33 cm) and 8 phase steps, the lens has a diffraction efficiency of 95%. By doubling the period, the focal length will be increased to 2F = 66.67 cm (focus power = 1.5 diopters), while still having an efficiency of 95%. By tripling the period, the focal length will be increased to 3F = 100 cm, corresponding to a focus magnification of 1 diopter, while still having the same efficiency. By quadrupling the period, the focal length will be increased to 4F = 133.32 cm, corresponding to a focusing power of 0.75 diopters, while still having the same efficiency. Similarly, larger focal lengths (smaller focusing magnifications) can be achieved with the same efficiency. When the lens is disconnected, there is no focus magnification. Table 2 shows parameters for various focus magnifications. The radii of each sub-region are shown in Tables 3-5 for 3 diopter, 1.5 diopter and 1 diopter lenses, respectively. These structural parameters can be calculated according to the equations presented herein. The relationship between the subregion boundaries of the three focusing magnifications can be easily derived.

Table 2 gives examples of some of the focus magnifications that can be obtained with individually addressable patterned electrodes. Assume that the basic focusing power is 3 diopters (F=33.3 cm) and the aperture of the lens is 10 mm. Table 2 shows that the diffraction efficiency remains the same when changing the focal length.

Table 2

Focus magnification phase grade Diffraction efficiency K value F'=kF The area of each subregion The width of the last subregion 3 diopters (F=33.33cm) 8 95% 1 1.453×10 ⁵ μm ² 4.6μm 1.5 diopters (F=66.67cm) 8 95% 2 2.906×10 ⁵ μm ² 9.2μm 1 diopter (F=100cm) 8 95% 3 4.359×10 ⁵ μm ² 13.8μm 0.75 diopters (F＝133.32cm) 8 95% 4 5.812×10 ⁵ μm ² 18.5μm 0 diopters (lens off) not applicable - gigantic - -

An important advantage of individually addressable patterned electrodes is that they provide exactly the same diffraction efficiency to the same lens with adaptability for different focusing magnifications.

In this application, the adjustable focal length is the base focal length F and multiples of the base focal length. Therefore, the adjusted resolution is also F. For example, if the electrodes are designed for a base focal length of 10 cm, then the adjustable focal lengths would be 10 cm, 20 cm, 30 cm, etc. up to infinity. A smaller base focal length may be used if other intermediate focal lengths are desired. However, when F is small, the feature size of the electrodes becomes very small for large-aperture lenses, and it is difficult to make it low-cost with currently available technologies.

2. Continuous adjustment of focal length

It is desirable to design adaptive lenses such that they can be utilized by all patients and applications. This requires the lens to have the ability to continuously change the focal length over the desired range. For this purpose, a more general design methodology was developed which allows continuous adjustment of the focal length. As mentioned above, the patterned electrodes are circular arrays of rings of specific dimensions. Each ring is individually addressable. The proper resolution of the ring is determined by the range of focal lengths to be adjusted. For each expected focal length, the size of each sub-region in all regions can be calculated using equations (2a) and (2b). A certain number of rings can be chosen to form each sub-region and appropriate voltages can be applied. If the resolution of these rings is good enough, the lens can always have high efficiency when the focal length is changed, and there is no significant change in efficiency. The required resolution of the patterned electrodes is determined by the size of the sub-areas in the last few areas of the desired lens, as described herein.

Figure 7 shows the continuous adjustment of focus using an individually addressable circular array of electrodes with appropriate resolution. The four examples in Figure 7 show the electrode spacing in μm for a subset of electrodes. The geometric parameters of the focus magnifications for 3D, 2.5D, 2D and ID are depicted in Examples A, B, C and D, respectively. r is the radius of the region boundary.

An example where the focal length is continuously varied from ~30 cm to infinity is illustrated here. Assume that the diameter of the lens is 10mm and that 8-level phase modulation is used. To illustrate the principle, the geometric parameters of 3D, 2.5D, 2D and 1D adjustable focus magnifications are depicted in Fig. 7, where the radii of each zone boundary and the The width of the subregion. More detailed parameters for these lenses can be found in Tables 3-7. It can be seen that the width of each sub-region varies very little at the edges of these lenses for a particular focusing power, and the variation is even smaller as the aperture of the lens increases. For larger focus magnifications, the width as well as the area of each sub-region is smaller. Each electrode is assumed to be 1 μm wide in the area. In this example, since the width of each sub-region is larger than 1 μm, several electrodes can be combined to form a sub-region, and the boundary of each sub-region is made close to the closest electrode boundary. Combining these electrodes means applying the same voltage to them.

For example, for the 2D case (example C), 7 electrodes can be combined to form all sub-regions of region 45 . All other subregions can be formed similarly. Round-off errors cause very small changes in diffraction efficiency. On the other hand, in a region close to the center of the lens, if approximately fine electrodes are used, the phase step can be larger than 8, and thus the diffraction efficiency in this region can be increased. In general, when adjusting the focusing magnification, the diffraction efficiency will be almost the same. When the focal length increases from 1 m (focus magnification 1D) to infinity, the width of each sub-region increases, and all sub-regions can be generated by combining the calculated number of electrodes. Thus, in this example, all focal lengths from ~30 cm to infinity (focus power from 0 to 3D) can be adjusted, and the lens can be used for all subjects requiring correction of vision at different distances within this range.

As noted above, due to the larger geometric size of the region near the center, the electrode density in this region can be smaller compared to the electrode density in the region near the edge (the electrode size near the center can be smaller than that in other regions). those electrode sizes are larger). If the density of the electrodes remains the same in the region near the center, then higher phase orders can be obtained and the diffraction orders will increase.

Another way to achieve this is to use pixilated spatial light modulators where small rectangular pixels are used. These pixels can be multilayered to reduce or eliminate gaps when viewed perpendicular to the substrate, similar to the 2-layer disk electrodes shown in Figure 5B.

Although the description herein contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing examples of some of the presently preferred embodiments of this invention. Additional embodiments are also within the scope of the invention. The invention is not limited to use with eyeglasses. The invention can also be used with microscopes, mirrors, binoculars, and any other optical device through which a user can view. Additionally, as will be apparent to one of ordinary skill in the art, the present invention is also useful in other fields, such as in telecommunications, optical switches, and medical devices. Any liquid crystal or mixture of liquid crystals that provides the desired phase transport function at the desired wavelength is useful in the present invention, as is known to those of ordinary skill in the art. Determining and applying suitable voltages to liquid crystal materials to produce the desired phase transfer function is well known in the art.

Unless stated otherwise, every device or combination of components described or illustrated can be used to practice the invention. Additional components such as drivers to apply the voltages used, controllers for the voltages, and any additional optical components are well known to those of ordinary skill in the art and may be incorporated without undue experimentation. Specific names of compounds are intended to be exemplary, as it is known that one of ordinary skill in the art can name the same compound by different names. When a compound is described herein such that no particular isomer or enantiomer of the compound is indicated, eg, by formula or by chemical name, that description is intended to include every one of the compounds described individually or in any combination. isomers and enantiomers. Those of ordinary skill in the art will appreciate that, without undue experimentation, methods, device elements, starting materials and fabrication methods other than those specifically illustrated may be employed in the practice of the invention. All art-known functional equivalents of any such methods, device elements, starting materials and fabrication methods are intended to be included in the present invention. When a range is given in the specification, such as a thickness range or a voltage range, all intermediate ranges and subranges and all individual values included within the given range are intended to be included in the disclosure.

As used herein, "comprising" is synonymous with "includes", "comprises", or "characterized by" and is inclusive or open-ended and does not exclude additional, non-recited element or method step. As used herein, "consisting of" excludes any element, step or ingredient not specified in a claim element. As used herein, "consisting essentially of" does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. Especially in the description of a composition of a composition or in a description of an element of a device, any recitation of the term "comprising" herein is to be understood as including consisting essentially of the recited parts or elements as well as consisting of said parts or elements Composition of those compositions and methods. The invention properly illustrated herein may be practiced without any element or elements, limitation or limitations, specifically disclosed herein.

The terms and expressions which have been employed are used as terms of description rather than limitation, and the use of such terms and expressions is not intended to exclude any equivalents to the features shown and described or parts thereof, and it will be recognized that in Various modifications are possible within the scope of the invention as claimed and described. Therefore, it should be understood that although the invention has been particularly disclosed with preferred embodiments and optional features, modifications and variations of the concepts disclosed herein may be adopted by persons of ordinary skill in the art, and such modifications and variations are considered to be within the scope of the present invention.

Generally, terms and phrases used herein have their art-recognized meanings, which can be derived by reference to standard texts, journal references and contexts well known to those of ordinary skill in the art. Certain definitions are provided to clarify their particular usage in the context of the present invention. All patents and publications mentioned in the specification are to the level of one of ordinary skill in the art to which the invention pertains.

Those skilled in the art will readily appreciate that the present invention is well adapted to carry out these objects and attain the ends and advantages mentioned and inherent therein. The apparatus and methods described herein as presently representative of preferred embodiments, and accompanying methods, are exemplary and not intended as limitations on the scope of the invention. Variations therein and other uses which may occur to those skilled in the art are encompassed within the spirit of the invention and defined by the scope of the claims.

All references cited herein are incorporated by reference to the extent not inconsistent with the disclosure of this specification. Some of the references provided herein are incorporated herein by reference to provide details regarding additional device components, additional liquid crystal cell configurations, additional patterns of patterned electrodes, additional analytical methods, and additional uses of the present invention.

"The eye and visual optical instruments" by G.Smith et al., Cambridge University Press, 1997.

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"Electrically controlled polarization-independent liquid-crystal Fresnel lens arrays (electrically controlled polarization-independent liquid-crystal Fresnel lens arrays)" by J.S.Patel et al., Opt.Lett.16:532-534, 1991.

"Liquid crystal used in switchable Fresnel lens" by B.Dance, Laser Focus World 28:34, 1992.

"Non-display applications of liquid crystal devices" by M.C.K.Wiltshire, GeoJ.Research 10:119-125, 1993.

"Tunable Fresnel lens using nanoscalepolymer-dispersed liquid crystals (tunable Fresnel lens using nanoscale polymer-dispersed liquid crystals)" by H.Ren et al., Appl.Phys.Lett.83:1515-1517, 2003 .

Liquid crystal lens review by C.W. Fowler et al., Ophthal. Physiol. Opt. 10:186-194, 1990.

J.A. Futhey, "Diffractive bifocal intraocular lens", Proc. SPIE 1052:142-149, 1989.

"Variable-focus liquid crystal Fresnel lens (variable focus liquid crystal Fresnel lens)" by S.Sato et al., Jpn.J.Appl.Phys.24:L626-L628, 1985.

"Variable focal length microlenses" by L.G.Commander et al., Opt.Commun.177:157-170, 2000.

"Focusing by electrical modulation of refraction in a liquid crystal cell" by S.T.Kowel et al., Appl.Opt.23:278-289, 1984.

Nouhi et al., "Adaptive spherical lens", Appl. Opt. 23: 2774-2777, 1984.

"Liquid-crystal adaptive lenses with modal control" by F.Naumov et al., Opt.Lett.23:992-994, 1998.

"Wave front controls systems based on modal liquid crystal lenses" by M.Y. Loktev et al., Rev. Sci. Instrum.71: 3190-3297, 2000.

"Three-terminal adaptive nematic liquid-crystal lens device" by N.A.Riza et al., Opt.Lett.19:1013-1015, 1994.

"A switchable liquid crystal binary Gaborlens" by P.W.McOwan et al., Opt.Commun.103:189-193, 1993.

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Kress et al., Digital Diffractive Optics, John Wiley & Sons Ltd., 2000.

Table 3. Outer diameter of each sub-region for a 3D, 15 mm, 8th order diffractive lens.

Subregion #1 2 3 4 5 6 7 8 Region# 1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27.28. 215.05608.25645.14860.19886.661053.511075.241216.491235.351360.081376.981489.891505.331609.271623.571720.381733.771824.741837.371923.441935.432017.322028.752107.032117.972193.062203.582275.852285.982355.732365.522432.982442.472507.862517.072580.572589.512651.282659.992720.162728.652787.332795.622852.932861.022917.042924.962979.782987.533041. 233048.823101.463108.903160.543167.853218.53   304.12680.04912.371096.531253.931393.671520.611637.751747.051849.911947.342040.122128.862214.052296.082375.282451.922526.232598.432668.672737.112803.872869.092932.862995.263056.403116.333175.14   372.47713.23937.371117.421272.241410.161535.751651.811760.241862.361959.172051.422139.692224.472306.132384.992461.332535.372607.312677.322745.542812.112877.142940.733002.973063.953123.743182.41   430.09744.95961.721137.921290.281426.461550.731665.751773.331874.741970.942062.662150.472234.842316.132304.672470.712544.472616.162685.942753.952820.322885.162948.583010.663071.493131.143189.67   480.86775.36985.471158.071308.081442.581565.571679.571786.321887.031982.642073.842161.202245.162326.092404.302480.052553.552624.992694.542762.332828.512893.172956.413018.333079.013138.513196.91    526.76804.631008.661177.861325.641458.521580.271693.281799.221899.251994.272084.962171.872255.442336.012413.902489.352562.592633.782703.102770.692836.672901.152964.223025.983086.513145.873204.13    568.96832.871031.331197.331342.971474.291594.831706.891812.021911382005.832096.022182.492265.662345.892423.462498.622571.592642.552711.642779.022844.812909.112972.013033.623093.993153.213211.34

29.30.31.32.33.34.35.36.37.38.39.40.41.42.43.44.45.46.47.48.49.50.51.52.53.54.55.56.57.58. 3225.713275.503282.563331.503338.433386.573393.393440.763447.473494.113500.723546.653553.173598.433604.853649.483655.813699.813706.063749.483755.643798.493804.583846.883852.893894.673900.613941.883947.753988.533994.334034.654040.374080.244085.904125.324130.934169.924175.464214.054219.534257.724263.154300.954306.324343.744349.064386.124391.394428. 104433.324469.684474.854510.874515.994551.704556.774592.164597.194632.26  3232.873289.593345.353400.203454.173507.323559.673611.263662.123712.293761.793810.653858.893906.533953.604000.114046.094091.564136.524181.004225.014268.574311.694354.384396.654438.534480.014521.114561.844602.21  3240.023296.613352.263406.993460.863513.903566.163617.663668.433718.523767.933816.713864.873912.443959.444005.894051.804097.204142.114186.534230.484273.984317.054359.684401.914443.734485.174526.224566.914607.24  3247.143303.623359.153413.773467.533520.483572.643624.043674.733724.733774.073822.773870.853918.353965.284011.664057.514102.844147.684192.054235.944279.394322.404364.994407.164448.934490.324531.334571.974612.25  3254.263310.613366.023420.543474.203527.043579.103630.423681.023730.933780.193828.813876.823924.253971.104017.424063.204108.474153.254197.564241.404284.794327.754370.284412.404454.134495.474536.434577.024617.26  3261.353317.593372.893427.293480.853533.593585.563636.783687.293737.123786.303834.843882.783930.133976.924023.174068.894114.104158.824203.064246.854290.184333.084375.574417.644459.324500.614541.524582.074622.27  3268.443324.553379.733434.033487.483540.133592.003643.133693.563743.313792.403840.873888.733936.013982.734028.914074.574119.724164.374208.564252.294295.574338.424380.854422.874464.504505.744546.614587.124627.27

59.60.61.62.63.64.65.66.67.68.69.70.71.72.73.74.75.76.77.78.79.80.81.82.83.84.85.86.87.88. 4637.254672.024676.974711.454716.364750.554755.424789.334794.164827.804832.594865.974870.724903.834908.554941.414946.094978.714983.355015.725020.335052.475057.045088.955093.495125.175129.685161.145165.625196.855201.305232.335236.755267.565271.955302.565306.925337.345341.675371.885376.185406.215410.485440.325444.565474.215478.435507.905512.105541. 385545.555574.675578.815607.755611.875640.645644.745673.345677.415705.85  4642.234681.914721.264760.284798.984837.374875.464913.264950.764987.995024.945061.615098.035134.195170.095205.755241.165276.345311.285345.995380.485414.755448.815482.655516.295549.725582.955615.995648.835681.48  4647.214686.854726.154765.134803.794842.154880.204917.964955.434992.625029.535066.185102.565138.695174.565210.195245.575280.725315.635350.325384.785419.025453.055486.875520.485553.895587.095620.115652.925685.55  4652.194691.784731.044769.984808.614846.924884.944922.664960.094997.255034.135070.745107.095143.195179.035214.625249.985285.095319.985354.645389.075423.295457.295491.085524.675558.055591.235624.225657.015689.62  4657.154696.714735.934774.834813.414851.694889.674927.354964.755001.875038.725075.305111.625147.685183.495219.055254.385289.475324.325358.955393.365427.555461.535495.295528.855562.215595.375628.335661.105693.68  4662.124701.634740.814779.674818.214856.454894.404932.044969.415006.505043.315079.855116.145152.175187.955223.485258.785293.845328.665363.275397.655431.815465.765499.505533.035566.365599.505632.445665.185697.74  4667.074706.544745.684784.504823.014861.214899.124936.734974.065011.115047.895084.405120.665156.655192.405227.915263.175298.205333.005367.585401.935436.065469.995503.705537.215570.525603.625636.545669.265701.80

89.90.91.92.93.94.95.96.97.98.99.100.101.102.103.104.105.106.107.108.109.110.111.112.113.114.115.116.117.118. 5709.905738.185742.215770.335774.335802.305806.285834.095838.055865.715869.655897.165901.085928.455932.355959.575963.455990.535994.396021.336025.176051.976055.796082.466086.266112.806116.586142.986146.746173.026176.776202.916206.646232.676236.376262.276265.976291.746295.426321.086324.736350.276353.916379.346382.966408.276411.876437.076440.666465. 746469.326494.296497.856522.716526.256551.016554.546579.186582.706607.24   5713.955746.235778.345810.265842.015873.595905.005936.245967.325998.246029.006059.616090.066120.366150.516180.516210.376240.086269.656299.096328.396357.556386.586415.486444.256472.896501.416529.806558.066586.21   5718.005750.265782.345814.245845.975877.525908.915940.145971.206002.106032.846063.426093.856124.136154.266184.256214.096243.786273.346302.766332.046361.196390.206419.086447.846476.466504.966533.346561.596589.72   5722.045754.285786.335818.215849.925881.465912.835944.035975.076005.956036.676067.236097.656127.916158.026187.996217.816247.496277.036306.436335.696364.826393.826422.686451.426480.036508.516536.876565.116593.23   5726.085758.295790.335822.195853.875885.395916.735947.925978.946009.806040.506071.046101.446131.686161.776191.726221.536251.196280.716310.096339.346368.456397.436426.286455.006483.606512.076540.416568.636596.73  5730.115762.315794.325826.165857.825889.325920.645951.805982.806013.646044.326074.856105.226135.456165.526195.456225.246254.896284.396313.766342.996372.086401.056429.886458.596487.166515.626543.956572.156600.24  5734.155766.325798.315830.125861.775893.245924.555955.695986.676017.496048.156078.666109.016139.226169.276199.196228.956258.586288.076317.426346.636375.716404.666433.486462.166490.736519.166547.486575.676603.74

119.120.121.122.123.124.125.126.127.128.129.130.131.132.133.134.135.136.137.138.139.140.141.142.143.144.145.146.147.148. 6610.746635.186638.666663.006666.476690.706694.166718.296721.746745.776749.206773.146776.556800.406803.796827.546830.936854.586857.956881.526884.886908.346908.696935.076938.406961.696965.016988.216991.527014.637017.937040.957044.247067.187070.457093.307096.567119.347122.587145.277148.517171.117174.347196.867200.077222.527225.727248.097251.287273. 567276.747298.957302.127324.257327.417349.467352.617374.597377.727399.63   6614.246642.146669.946697.616725.176752.626779.966807.196834.316861.336888.236915.046941.736968.336994.837021.227047.527073.727099.827125.837151.747177.567203.287228.927254.467279.927305.287330.567355.757380.86   6617.736645.636673.406701.066728.616756.056783.376810.596837.706864.696891.596918.386945.066971.656998.137024.527050.807076.997103.087129.077154.977180.787206.497232.127257.657283.097308.457333.717358.897383.99   6621.226649.106676.876704.516732.056759.476786.786813.986841.086868.066894.946921.726948.396974.967001.447027.817054.087080.257106.337132.317158.207184.007209.707235.317260.847286.277311.617336.877362.047387.12   6624.726652.586680.336707.966735.486762.896790.196817.376844.466871.436898.306925.066951.726978.287004.747031.107057.367083.527109.587135.567161.437187.227212.917238.517264.027289.447314.777340.027365.187390.25   6628.216656.066683.796711.416738.916766.316793.596820.776847.836874.796901.656928.406955.056981.597008.047034.387060.637086.787112.847138.807164.667190.437216.117241.707267.207292.617317.937343.177368.327393.38   6631.696659.536687.256714.856742.346769.726796.996824.166851.216878.166905.006931.736958.376984.907011.347037.677063.917090.047116.097142.037167.897193.657219.327244.897270.387295.787321.097346.327371.457396.50

149.150.151.152. 7402.757424.597427.707449.467452.567474.257477.347498.96 7405.887430.817455.677480.43 7409.007433.927458.777483.53 7412.127437.037461.877486.61 7415.247440.147464.967489.70 7418.367443.257468.067492.79 7421.477446.367471.167495.87

Table 4. Outer diameter of each sub-region for a 1.5D, 15mm, 8th order diffractive lens. The area of each region is twice the area of the corresponding 3D lens (Table 3).

subregion. 1 2 3 4 5 6 7 8 area# 1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27. 304.12860.19912.371216.491253.931489.891520.611720.381747.051923.441947.342107.032128.862275.852296.082432.982451.922580.572598.432720.162737.112852.932869.092979.782995.263101.463116.333218.533232.873331.503345.353440.763454.173546.653559.673649.483662.123749.483761.793846.883858.893941.883953.604034.654046.094125.324136.524214.054225.014300. 954311.694386.124396.65  430.09961.721290.281550.731773.331970.942150.472316.132470.712616.162753.952885.163010.663131.143247.143359.153467.533572.643674.733774.073870.853965.284057.514147.684235.944322.404407.16  526.761008.661325.641580.271799.221994.272171.872336.012489.352633.782770.692901.153025.983145.873261.353372.893480.853585.563687.293786.303882.783976.924068.894158.824246.854333.084417.64   608.251053.511360.081609.271824.742017.322193.062355.732507.862651.282787.332917.043041.233160.543275.503386.573494.113598.433699.813798.493894.673988.534080.244169.924257.724343.744428.10  680.041096.531393.671637.751849.912040.122214.052375.282526.232668.672803.872932.863056.403175.143289.593400.203507.323611.263712.293810.653906.534000.114091.564181.004268.574354.384438.53  744.951137.921426.461665.751874.742062.662234.842394.672544.472685.942820.322948.583071.493189.673303.623413.773520.483624.043724.733822.773918.354011.664102.844192.054279.394364.994448.93   804.631177.861458.521693.281899.252084.962255.442413.902562.592703.102836.672964.223086.513204.133317.593427.293533.593636.783737.123834.843930.134023.174114.104203.064290.184375.574459.32

28.29.30.31.32.33.34.35.36.37.38.39.40.41.42.43.44.45.46.47.48.49.50.51.52.53.54.55.56.57. 4469.684480.014551.704561.844632.264642.234711.454721.264789.334798.984865.974875.464941.414950.765015.725024.945088.955098.035161.145170.095232.335241.165302.565311.285371.885380.485440.325448.815507.905516.295574.675582.955640.645648.835705.855713.955770.335778.345834.095842.015897.165905.005959.575967.326021.336029.006082.466090.066142.986150. 516202.916210.376262.276269.656321.086328.396379.346386.586437.076444.25 4490.324571.974652.194731.044808.614884.944960.095034.135107.095179.035249.985319.985389.075457.295524.675591.235657.015722.045786.335849.925912.835975.076036.676097.656158.026217.816277.036335.696393.826451.42 4500.614582.074662.124740.814818.214894.404969.415043.315116.145187.955258.785328.665397.655465.765533.035599.505665.185730.115794.325857.825920.645982.806044.326105.226165.526225.246284.396342.996401.056458.59 4510.874592.164672.024750.554827.804903.834978.715052.475125.175196.855267.565337.345406.215474.215541.385607.755673.345738.185802.305865.715928.455990.536051.976112.806173.026232.676291.746350.276408.276465.74 4521.114602.214681.914760.284837.374913.264987.995061.615134.195205.755276.345345.995414.755482.655549.725615.995681.485746.235810.265873.595936.245998.246059.616120.366180.516240.086299.096357.556415.486472.89 4531.334612.254691.784769.984846.924922.664997.255070.745143.195214.625285.095354.645423.295491.085558.055624.225689.625754.285818.215881.465944.036005.956067.236127.916187.996247.496306.436364.826422.686480.03 4541.524622.274701.634779.674856.454932.045006.505079.855152.175223.485293.845363.275431.815499.505566.365632.445697.745762.315826.165889.325951.806013.646074.856135.456195.456254.896313.766372.086429.886487.16

58.59.60.61.62.63.64.65.66.67.68.69.70.71.72.73.74.75.76.   6494.296501.416551.016558.066607.246614.246663.006669.946718.296725.176773.146779.966827.546834.316881.526888.236935.076941.736988.216994.837040.957047.527093.307099.827145.277151.747196.867203.287248.097254.467298.957305.287349.467355.757399.637405.887449.467455.677498.96 6508.516565.116621.226676.876732.056786.786841.086894.946948.397001.447054.087106.337158.207209.707260.847311.617362.047412.87 6515.626572.156628.216683.796738.916793.596847.836901.656955.057008.047060.637112.847164.667216.117267.207317.9367368.3274168.306 6522.716579.186635.186690.706745.776800.406854.586908.346961.697014.637067.187119.347171.117222.527273.567324.2575374.597424.59 6529.806586.216642.146697.616752.626807.196861.336915.046968.337021.227073.727125.837177.567228.927279.927330.567380.8637480.81 6536.876593.236649.106704.516759.476813.986868.066921.726974.967027.817080.257132.317184.007235.317286.277336.877387.117436.03 6543.956600.246656.066711.416766.316820.776874.796928.406981.597034.387086.787138.807190.437241.707292.617343.177393.3874493.27

Table 5. Outer diameter of each sub-region for 1D, 15mm, 8th order diffractive lens. The area of each region is three times the area of the corresponding 3D lens (Table 3). The area of each region is twice the area of the corresponding 2D lens (Table 4).

area# 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051 372.491117.471535.821862.462139.802385.112607.442812.253003.123182.573352.423514.083668.623816.903959.644097.414230.694359.904485.394607.474726.394842.394955.685066.435174.825280.985385.055487.145587.375685.845782.625877.825971.496063.726154.576244.106332.366419.406505.296590.056673.746756.396838.046918.726998.487077.347155.337232.487308.817384. 367459.14 526.781177.921580.351899.342171.982414.022633.912836.813026.143204.293373.053533.773687.483835.043977.124114.304247.064375.794500.834622.504741.044856.704969.665080.115188.215294.105397.925499.775599.785698.035794.615889.615983.106075.156165.836255.206343.306430.206515.946600.576684.126766.656848.176928.747008.397087.147165.027242.067318.307393. 757468.43 645.171235.411623.651935.522203.692442.592660.122861.163048.983225.873393.563553.343706.243853.083994.534131.134263.364391.614516.224637.484755.654870.964983.605093.755201.565307.195410.755512.375612.155710.195806.575901.385994.696086.566177.076266.286354.236440.986526.586611.076694.496776.896858.306938.757018.287096.927174.707251.647327.777403. 127477.72 744.981290.351665.831971.042234.952470.832686.082885.313071.643247.313413.943572.813724.923871.054011.864147.894279.604407.384531.564652.424770.224885.184997.505107.355214.885320.245423.565524.945624.505722.325818.505913.126006.256097.956188.306277.346365.146451.746537.206621.566704.856787.126868.416948.747028.167106.697184.367261.207337.237412. 497486.99 832.921343.041706.972005.932265.782498.752711.782909.253094.153268.603434.203592.183743.493888.934029.114164.584295.784423.094546.844667.314784.744899.365011.365120.915228.175333.275436.345537.495636.825734.445830.425924.846017.796109.326199.506288.386376.036462.496547.806632.026715.196797.336878.506958.727038.027116.447194.017270.757346.687421. 847496.25 912.411393.741747.142040.22229 6.192526.362737.242933.003116.493289.763454.353611.443761.983906.724046.294181.214311.904438.754562.074682.154799.224913.505025.195134.445241.425346.265449.085550.005649.115746.525842.305936.546029.306120.666210.686299.406386.906473.216558.396642.486725.516807.536888.586968.687047.877126.187203.647280.287356.127431 .187505.50 985.521442.651786.412073.952326.212553.672762.472956.563138.673310.783474.373630.603780.383924.444063.404197.774327.964454.354577.254696.944813.654927.605038.975147.945254.645359.225461.805562.495661.385758.585854.175948.216040.806131.996221.846310.416397.756483.926568.966652.916735.826817.726898.646978.637057.717135.917213.277289.807365.547440. 517514.74 1053.571489.971824.832107.132355.842580.702787.472979.933160.703331.673494.283649.663798.683942.084080.444214.264343.964469.904592.394711.694828.044941.665052.725161.405267.835372.155474.495574.945673.625770.625866.005959.876052.276143.296232.986321.396408.596494.616579.516663.336746.116827.886908.696988.567067.537145.637222.887299.327374.967449. 837523.96

Table 6. Outer diameter of each sub-region for a 2D, 15 mm, 8th order diffractive lens.

subregion# 1 2 3 4 5 6 7 8 Region# 1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27.28.29.30.31.32.33.34.35.36.37.38.39.40.45.42.440.464.47.475 51.52.53.54.55.56. 263.39790.171085.991316.961513.071686.531843.741988.562123.532250.422370.522484.832594.102698.962799.892897.302991.553082.923171.653257.973342.063424.093504.193582.513659.153734.223807.803880.003950.874020.494088.934156.254222.484287.704351.944415.244477.654539.204599.934659.874719.044777.494835.224892.284948.675004.445059.585114.135168.115221. 535274.415326.765378.605429.955480.825531.22 372.49832.921117.471343.041535.821706.971862.462005.932139.802265.782385.112498.752607.442711.782812.252909.253003.123094.153182.573268.603352.423434.203514.083592.183668.623743.493816.903888.933959.644029.114097.414164.584230.694295.784359.904423.094485.394546.844607.474667.314726.394784.744842.394899.364955.685011.365066.435120.915174.825228. 175280.985333.275385.055436.345487.145537.49 456.21873.571148.101368.621558.241727.171880.992023.152155.952281.042399.612512.592620.712724.542824.562921.153014.653105.343193.453279.203362.763444.293523.943601.823678.063752.753825.983897.843968.394037.714105.864172.904238.884303.854367.854430.934493.124554.464614.994674.734733.724791.994849.554906.444962.675018.285073.285127.685181.525234. 805287.545339.775391.495442.715493.465543.75 526.78912.411177.921393.741580.351747.141899.342040.222171.982296.192414.022526.362633.912737.242836.812933.003026.143116.493204.293289.763373.053454.353533.773611.443687.483761.983835.043906.723977.124046.294114.304181.214247.064311.904375.794438.754500.834562.074622.504682.154741.044799.224856.704913.504969.665025.195080.115134.445188.215241. 425294.105346.265397.925449.085499.775550.00 588.96949.671207.011418.411602.151766.881917.522057.152187.892311.252428.352540.052647.052749.892849.012944.803037.583127.603215.103300.283383.323464.373543.573621.033696.873771.193844.073915.593985.834054.864122.734189.504255.224319.944383.714446.564508.534569.674630.004689.554748.354806.444863.834920.564976.635032.085086.935141.195194.895248. 045300.655352.745404.345455.445506.085556.25 645.17985.521235.411442.651623.651786.411935.522073.952203.692326.212442.592553.672660.122762.472861.162956.563048.983138.673225.873310.783393.563474.373553.343630.603706.243780.383853.083924.443994.534063.404131.134197.774263.364327.964391.614454.354516.224577.254637.484696.944755.654813.654870.964927.604983.605038.975093.755147.945201.565254. 645307.195359.225410.755461.805512.375562.49 696.871020.111263.181466.501644.881805.721953.362090.602219.372341.072456.752567.222673.132775.002873.262968.273060.333149.703236.613321.243403.773484.343563.093640.143715.593789.543862.083933.274003.204071.934139.524206.024271.494335.974399.504462.134523.894584.834644.964704.324762.944820.854878.084934.644990.555045.855100.555154.675208.235261. 245313.725365.695417.165468.155518.665568.72 744.981053.571290.351489.971665.831824.831971.042107.132234.952355.842470.832580.702686.082787.472885.312979.933071.643160.703247.313331.673413.943494.283572.813649.663724.923798.683871.053942.084011.864080.444147.894214.264279.604343.964407.384469.904531.564592.394652.424711.694770.224828.044885.184941.664997.505052.725107.355161.405214.885267. 835320.245372.155423.565474.495524.945574.94

57.58.59.60.61.62.63.64.65.66.67.68.69.70.71.72.73.74.75.76.77.78.79.80.81.82.83.84.85.86.87.88.89.90.91.92.91.94.95.906.97   5581.165630.665679.735728.385776.625824.465871.915918.985965.686012.026058.006103.646148.936193.906238.546282.866326.886370.596414.006457.126499.956542.516584.786626.796668.546710.026751.256792.236832.966873.456913.716953.736993.527033.097072.447441.577150.487189.187227.687265.977304.077341.967379.667417.177454.497491.62   5587.375636.825685.845734.445782.625830.425877.825924.845971.496017.796063.726109.326154.576199.506244.106288.386332.366376.036419.406462.496505.296547.806590.056632.026673.746715.196756.396797.336838.046878.506918.726958.726998.487038.027077.347116.447155.337194.017232.487270.757308.817346.687384.367421.847459.147496.25  5593.585642.975691.945740.485788.625836.365883.725930.695977.306023.556069.446114.996160.206205.096249.656293.906337.836381.476424.816467.856510.626553.106595.316637.256678.936720.356761.526802.446843.116883.546923.746963.707003.447042.957082.247121.317160.187198.837237.277275.527313.567351.407389.057426.517463.797500.87  5599.785649.115698.035746.525794.615842.305889.615936.545983.106029.306075.156120.666165.836210.686255.206299.406343.306386.906430.206473.216515.946558.396600.576642.486684.126725.516766.656807.536848.176888.586928.746968.687008.397047.877047.147126.187165.027203.647242.067280.287318.307356.127393.757431.187468.437505.50  5605.975655.255704.115752.555800.595848.245895.505942.385988.906035.056080.866126.336171.466216.266260.746304.916348.776392.336435.596478.576521.266563.686605.826647.706689.316730.676771.776812.636853.246893.616933.756973.667013.347052.797092.037131.057169.867208.467246.857285.047323.047360.837398.447435.857473.087510.12  5612.155661.385710.195758.585806.575854.175901.385948.215994.696040.806086.566131.996177.076221.846266.286310.416354.236397.756440.986483.926526.586568.966611.076652.916694.496735.826776.896817.726858.306898.646938.756978.637018.287057.717096.927135.917174.707213.277251.647289.807327.777365.547403.127440.517477.727514.74  5618.335667.515716.265764.605812.545860.095907.255954.046000.476046.546092.266137.646182.696227.416271.816315.906359.696403.176446.376489.276531.896574.246616.326658.126699.67640.976782.016822.806863.356903.676943.756983.607023.227062.627101.807140.777179.537218.087256.427294.567332.507370.257407.817445.177482.357519.35  5624.505673.625722.325770.625818.505866.005913.125959.876006.256052.276097.956143.296188.306232.986277.346321.396365.146408.596451.746494.616537.206579.516621.566663.336704.856746.116787.126827.886868.416908.696948.746988.567028.167067.537106.697145.637184.367222.887261.207299.327337.237374.967412.497449.837486.997523.96

Table 7. Outer diameter of each sub-region for a 2.5D, 15mm, 8th order diffractive lens.

subregion# 1 2 3 4 5 6 7 8 Region# 1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.26.27.28.29.30.31.32.33.34.35.36.37.38.39.40.45.42.440.464.47.475 51.52.53.54.55.56. 235.58706.75971.341177.921353.331508.481649.091778.621899.342012.832120.262222.502320.242414.022504.302591.432675.722757.442836.812914.022989.233062.603134.253204.293272.843339.993405.803470.373533.773596.043657.253717.463776.703835.043892.493949.114004.934059.994114.304167.914220.844273.114324.754375.794426.234476.104525.434574.224622.504670. 284717.574764.404810.774856.704902.194947.27 333.17744.98999.501201.251373.681526.761665.831794.161913.902026.572133.312234.952332.172425.492515.352602.112686.082767.492846.582923.532998.503071.643143.093212.943281.313348.283413.943478.363541.613603.753664.833724.923784.053842.263899.623956.134011.864066.824121.044174.574227.414279.604331.174382.124432.494482.304531.564580.284628.504676. 224723.454770.224816.534862.414907.854952.88 408.04781.341026.891224.131393.741544.831682.411809.561928.342040.222146.282247.332344.032436.902526.362612.762696.392777.502856.312933.003007.743080.673151.903221.573289.763356.563422.063486.333549.443611.443672.403732.363791.373849.483906.723963.144018.774073.634127.774181.214233.974286.084337.574388.454438.754488.494537.684586.344634.494682. 154729.324776.034822.294868.114913.504958.48 471.17816.091053.571246.601413.511562.691698.821824.831942.682053.782159.172259.652355.842448.262537322623362706.662787.472866.012942.453016.953089.663160.703230.173298.183364.823430.163494.283557.253619.123679.953739.793798.683856.683913.823970.144025.674080.444134.494187.844240.524292.554343.964394.774445.004494.664543.794592.394640.474688.074735.194781. 844828.044873.814919.154964.07 526.78849.411079.581268.661433.001580.351715.081839.971956.912067.242171.982271.892367.592459.572548.232633.912716.892797.412875.672951.863026.143098.633169.463238.753306.583373.053438.243502.213565.043626.783687.483747.203805.983863.873920.913977.124032.564087.244141.204194.464247.064299.014350.344401.084451.244500.834549.894598.424646.454693. 994741.044787.644833.794879.504924.784969.66 577.06881.481104.991290.351452.241597.811731.181854.991971.042080.622184.722284.082379.292470.832559.102644.432727.092807.312885.312961.253035.293107.573178.213247.313314.973381.273446.303510.133572.813634.423695.003754.603813.273871.053927.983984.094039.434094.024147.894201.074253.594305.464356.724407.384457.474506.994555.994604.454652.424699. 894746.894793.434839.524885.184930.424975.24 623.30912.411129.821311.681471.221615.091747.141869.891985.072093.922197.382296.192390.922482.042569.922654.902737.242817.182894.912970.613044.423116.493186.933255.843323.333389.473454.353518.033580.573642.053702.503761.983820.543878.213935.033991.054046.294100.794154.584207.674260.114311.904363.084413.674463.694513.154562.074610.484658.384705. 794752.744799.224845.264890.864936.044980.81 666.33942.341154.121332.671489.971632.181762.951884.681999.002107.132209.982308.252402.502493.192580.702665.332747.362827.012904.482979.933053.523125.383195.623264.353331.673397.653462.373525.903588.313649.663709.993769.353827.793885.363942.083998.004053.154107.554161.254214.264266.614318.334369.444419.954469.904519.294568.154616.494664.334711. 694758.574805.004850.984896.534941.664986.38

57.58.59.60.61.62.63.64.65.66.67.68.69.70.71.72.73.74.75.76.77.78.79.80.81.82.83.84.85.86.87.88.89.90.91.92.93.94.95.96.97.98.99.100.101.102.103.104.105.106. 107.108.109.110.111.112.113.114.115.116. 4991.945036.225080.115123.625166.775209.565252.005294.105335.875377.315418.445459.265499.775539.995579.925619.565658.935698.035736.855775.425813.735851.795889.615927.185964.526001.626038.506075.156111.596147.806183.816219.616255.206290.596325.786360.786395.586430.206464.636498.886532.956566.856600.576634.126667.506700.716733.766766.656799.376831. 956864.366896.636928.746960.716992.537024.217055.747087.147118.397149.51 4997.505041.735085.575129.035172.145214.885257.285299.345341.075382.475423.565464.345504.825545.005584.895624.405663.835702.895741.695780.225818.505856.535894.325931.865969.176006.256043.106079.726116.136152.326188.306224.076259.636295.006330.176365.146399.926434.526468.936503.156537.206571.076604.776638.306671.666704.856737.886770.756803.466836. 016868.416900.656932.756964.706996.507028.167059.677091.057122.297153.39 5003.055047.235091.025134.445177.505220.205262.565304.575346.265387.625428.675469.415509.855550.005589.865629.435668.735707.765746.525785.025823.275861.275899.035936.545973.826010.876047.696084.286120.666156.836192.786228.526264.066299.406334.556369.506404.266438.836473.216507.426541.446575.296608.976642.486675.816708.996742.006774.846807.536840. 076872.446904.676936.756968.687000.467032.107063.607094.967126.187157.27 5008.595052.725096.475139.845182.865225.515267.835309.805351.455392.775433.785474.495514.895555.005594.825634.365673.625712.625751.355789.825828.045866.005903.735941.215978.466015.486052.276088.846125.196161.336197.266232.986268.496303.816338.936373.856408.596443.146477.506511.686545.696579.516613.176646.656679.976713.126746.116778.946811.616844. 126876.486908.696940.756972.667004.437036.057067.537098.877130.087161.15 5014.135058.215101.915145.245188.215230.825273.095315.035356.635397.925438.895479.555519.925559.995599.785639.285678.515717.475756.175794.615832.805870.735908.435945.885983.106020.096056.866093.406129.726165.836201.736237.436272.926308.216343.306378.216412.926447.446481.786515.946549.926583.736617.366650.836684.126717.256750.226783.036815.686848. 176880.526912.716944.756976.647008.397039.997071.467102.787133.977165.02 5019.665063.695107.355150.635193.555236.125278.355320.245361.815403.055443.995484.615524.945564.985604.735644.205683.405722.325760.995799.405837.555875.465913.125950.555987.746024.706061.446097.956134.256170.336206.216241.876277.346312.616347.686382.556417.246451.746486.066520.206554.166587.946621.566655.006688.276721.386754.336787.126819.756852. 236884.556916.726948.746980.627012.357043.937075.387106.697137.867168.89 5025.195069.175112.785156.025198.895241.425283.615325.465366.985408.195449.085489.675529.965569.965609.685649.115688.285727.175765.805804.185842.305880.185917.815955.215992.376029.306066.016102.506138.776174.836210.686246.326281.766317.006352.056386.906421.576456.046490.346524.456558.396592.156625.756659.176692.426725.516758.446791.216823.826856. 276888.586920.736952.736984.597016.307047.877079.307110.597141.747172.76 5030.715074.645118.205161.405204.235246.715288.865330.675372.155413.325454.175494.725534.985574.945614.625654.035693.155732.025770.625808.965847.055884.905922.505959.875997.006033.906070.586107.056143.296179.326215.146250.766286.186321.396356.416391.246425.896460.346494.616528.716562.626596.366629.936663.336696.576729.646762.546795.296827.886860. 326892.606924.746956.726988.567020.267051.817083.227114.497145.637176.63

117.118.119.120.121.122.123.124.125.126.127. 7180.497211.357242.067272.657303.127333.457363.667393.757423.717453.567483.28 7184.367215.197245.907276.477306.917337.237367.437397.507427.457457.287486.99 7188.227219.047249.727280.287310.717341.017371.197401.257431.187461.007490.69 7192.087222.887253.557284.097314.517344.797374.967405.007434.927464.727494.40 7195.947226.727257.387287.907318.307348.577378.727408.747438.657468.437498.10 7199.797230.567261.207291.717322.097352.57382.487412.497442.387472.157501.80 7203.647234.407265.027295.517325.887356.127386.247416.237446.117475.867505.50 7207.507238.237268.847299.327329.677359.897389.997419.977449.837479.577509.19

Claims (25)

CLAIMS 1. An adjustable focus, electrically controllable electro-active lens comprising: A liquid crystal layer positioned between a pair of transparent substrates; a Fresnel region patterned electrode having M regions each having L regions between the liquid crystal layer and the inwardly facing surface of the first transparent substrate individually addressable subregions, where M and L are positive integers; and A conductive layer between the liquid crystal layer and the inwardly facing surface of the second transparent substrate. 2. The lens of claim 1, wherein the Fresnel zones are on the same level as the individually addressable sub-regions of the patterned electrode. 3. The lens of claim 1, wherein the liquid crystal is selected from the group consisting of: nematic, cholesteric, electroactive polymer, polymer liquid crystal, polymer dispersed liquid crystal, polymer Stable liquid crystals, and self-assembled nonlinear supramolecular structures. 4. The lens of claim 3, wherein the liquid crystal is nematic. 5. The lens of claim 4, wherein the liquid crystal is E7. 6. The lens of claim 1, wherein the transparent substrate is glass. 7. The lens of claim 1, wherein the transparent substrate is plastic. 8. The lens of claim 1, further comprising electrical control means electrically connected to the individually addressable sub-regions and the conductive layer. 9. A lens as claimed in claim 8, wherein the electrical control means applies positive or negative voltages to the individually addressable sub-areas. 10. The lens of claim 9, wherein the voltage is between negative 3 volts and positive 3 volts. 11. The lens of claim 8, further comprising a distance measuring device electrically connected to the electrical control means. 12. The lens of claim 1, wherein the patterned electrode and the conductive layer are transparent. 13. The lens of claim 12, wherein the patterned electrodes and conductive layer are indium tin oxide. 14. The lens of claim 1, further comprising an alignment layer around the liquid crystal layer. 15. The lens of claim 14, wherein the alignment layer is polyvinyl alcohol. 16. The lens of claim 14, wherein the alignment layer is nylon 6,6. 17. The lens of claim 1, wherein the transparent substrates are separated by between about 3 microns and about 20 microns. 18. The lens of claim 1, wherein the focal length is positive. 19. The lens of claim 1, wherein the focal length is negative. 20. A method for adjusting the focal length of a lens to an integer multiple of the initial focal length F, the method comprising: A lens is provided, comprising: a liquid crystal layer sealed between a pair of transparent substrates; a Fresnel zone patterned electrode positioned between the liquid crystal layer and an inwardly facing surface of the first transparent substrate, said being The patterned electrode has M areas, each area has L sub-areas, and the patterned electrode has M·L individually addressable electrodes in total; and an electrical control device electrically connected to the electrode region and the conductive layer; applying the same voltage to every k individually addressable electrodes, thereby adjusting the focal length to k F, where k is from 1 to M Integer of L. 21. The method of claim 20, wherein the applied voltage is between negative 3 volts and positive 3 volts. 22. A method of continuously adjusting the focal length of a lens, the method comprising: (a) providing a lens comprising: a liquid crystal layer sealed between a pair of transparent substrates; a Fresnel region patterned electrode having an inwardly facing surface located between the liquid crystal layer and the first transparent substrate The patterned electrode is a circular array of individually addressable rings; a conductive layer between the liquid crystal layer and the inwardly facing surface of the second transparent substrate; and electrically connected to the electrode region and electrical control means of the conductive layer; (b) determine the desired focal length (f'); (c) Calculate the area of the mth region of the patterned electrode in the Fresnel zone using the equation: r _m ² +f' ² =(f'+mλ) ² , where f' is the design focal length and λ is the design wavelength ; (d) dividing the calculated area of the mth region by an integer of L or greater to determine the number of individually addressable electrodes forming the designed subregion; (e) Apply the same voltage to these numbers of individually addressable electrodes in the designed sub-region. 23. The method of claim 22, further comprising before step (a): determining one or more design focal lengths; Calculate the largest ring size in the Fresnel zone patterned electrode that allows all design focal lengths to be formed in the design sub-region. 24. The method of claim 22, further comprising determining a design focal length using a distance measuring device to determine the distance between the lens and the desired object. 25. The method of claim 22, wherein the applied voltage is between negative 3 volts and positive 3 volts.

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