CN116088230A

CN116088230A - Liquid crystal lens and preparation method thereof

Info

Publication number: CN116088230A
Application number: CN202310120780.2A
Authority: CN
Inventors: 庄林凡; 刘国栋; 曾吉勇
Original assignee: Lianchuang Electronic Technology Co ltd
Current assignee: Lianchuang Electronic Technology Co ltd
Priority date: 2023-02-16
Filing date: 2023-02-16
Publication date: 2023-05-09

Abstract

The invention provides a liquid crystal lens and a preparation method thereof. The liquid crystal lens has a simple structure, the surfaces of all layers are flat, the alignment of liquid crystal molecules is easy, and the processing and the production are easy. The plurality of first electrodes in the first electrode layer are divided into a plurality of groups, the plurality of first electrodes in the second electrode layer are divided into a plurality of groups, each group of first electrodes is provided with a preset electrode sampling rate, and the electrode sampling rate of the group close to the optical axis is larger than that of the group far away from the optical axis, so that the size of the liquid crystal lens can be larger. The first electrode layer and the first common electrode layer are respectively arranged in the first half area and the second half area of the first substrate, and the second common electrode layer and the second electrode layer are respectively arranged in the third half area and the fourth half area of the second substrate, so that the optical path difference distribution of the liquid crystal lens can be effectively improved, and the problem of decentration of the liquid crystal lens is solved.

Description

Liquid crystal lens and preparation method thereof

Technical Field

The invention relates to the technical field of lenses, in particular to a liquid crystal lens and a preparation method thereof.

Background

The liquid crystal lens is mainly formed by arranging electrodes on two substrates on two sides of a liquid crystal layer respectively (a common electrode on one substrate and a driving electrode on the other substrate), applying driving voltages with different magnitudes on different electrodes, and forming vertical electric fields with different intensities between the two substrates to drive liquid crystal molecules to be arranged. Therefore, only the voltage distribution on the corresponding electrode needs to be controlled, and the refractive index distribution of the liquid crystal lens is changed accordingly, so that the distribution of the outgoing light passing through the liquid crystal lens is controlled. The function of the Fresnel liquid crystal lens can be realized by controlling the voltage distribution on the corresponding electrode to form gradient distribution with nonuniform refractive index in the liquid crystal layer of the liquid crystal lens.

FIG. 9 shows an optical path difference distribution curve of a conventional equal-height Fresnel liquid crystal lens, which is generally divided into a plurality of regions from the center to the edge, and the width of each region gradually decreases from the center to the edge (i.e., W1 'W2' W3 '… > Wi' in FIG. 9), but the same number of driving electrodes are provided in each region, and thus the width of the driving electrodes is also smaller and smaller. For a fresnel lens, there is an annular serrated surface (or convex surface in the center) that is a zone (or one lobe of the fresnel liquid crystal lens that is a zone); for a fresnel liquid crystal lens, one voltage repeating unit can be considered as one region, i.e., how many voltage repeating units there are, and how many regions there are. When the fresnel liquid crystal lens is large in size, the line width (width) of the driving electrode located at the edge of the lens is reduced to an unacceptable level, for example, the line width is too small to be processed, or the transition of the electric field with the line width too small cannot effectively control the liquid crystal molecules, so that further expansion of the size of the liquid crystal lens is limited, and the application of the liquid crystal lens is also limited.

To further expand the size of liquid crystal lenses, the prior art provides an electro-active lens comprising a substrate with a stepped surface defining concentric liquid crystal regions of increasing thickness with the radius of the lens. Each region is switched by a different set of ring electrodes, which may be on, below or opposite the stepped surface. The farther the ring electrode is from the center of the lens in each region, the narrower the ring electrode becomes, but the width of the ring electrode also increases with the thickness of the liquid crystal, thereby counteracting the decrease in width that would degrade the performance of the lens. Although the size of the electroactive lens can be made larger, the step difference exists around the step, so that the orientation of nearby liquid crystal molecules is difficult, the optical path difference distribution curve is suddenly changed at the step position, and a plurality of liquid crystal devices with different thicknesses are difficult to process.

At present, a driving electrode in a liquid crystal lens is arranged on one side of a liquid crystal layer, a common electrode is arranged on the other side of the liquid crystal layer and limited by a single friction direction of a substrate, an optical path difference distribution curve formed by the liquid crystal lens has asymmetry relative to the geometric center of the lens, and the liquid crystal lens has the problem of eccentricity. Fig. 10 shows a prior art optical path difference distribution curve (parallel rubbing alignment direction) and a standard curve (phi=r) of a liquid crystal lens having a ring electrode ² And/2 f, where φ is the liquid crystal lens optical path difference, r is the lens radius, and f is the lens focal length), the optical path difference of the lens cannot be axisymmetric about the geometric axis as a center, compared with a standard curve, mainly due to the direction of rubbing alignment, and the phenomenon is more remarkable as the pretilt angle is larger.

Cell thickness (Ce l l gap) and pretilt angle (Pre ang l e) are two important parameters affecting the performance of the liquid crystal display panel. (1) The thickness of the liquid crystal layer disposed between the upper and lower substrates affects the transmittance of the liquid crystal display panel and the reaction time of the liquid crystal. In order to obtain the display effect with high contrast, high brightness and high response speed, the thickness of the box needs to be strictly controlled, and meanwhile, the uniformity of the thickness of the box needs to be ensured, so that the color unevenness caused by the change of the ground color of the liquid crystal display is avoided. (2) In order to make the arrangement of the liquid crystal molecules regular, a Polyimide (PI) guide film is respectively arranged on one side of the upper and lower substrates close to the liquid crystal layer, wherein the acting force between the branched chain group in the PI guide film and the liquid crystal molecules is stronger, and the liquid crystal molecules are anchored, so that the liquid crystal molecules are aligned at a polar angle inclined relative to the surface of the P I guide film, and the polar angle is the pretilt angle of the liquid crystal layer. The pretilt angle can control the orientation of liquid crystal molecules, prevent the occurrence of anti-tilt domains in the liquid crystal layer, and can influence the light transmittance-voltage curve of the liquid crystal layer to a certain extent, and the proper pretilt angle can reduce the threshold voltage and accelerate the response speed of the liquid crystal.

The matters in the background section are only those known to the inventors and do not, of course, represent prior art in the field.

Disclosure of Invention

In view of one or more of the deficiencies of the prior art, the present invention provides a liquid crystal lens having an optical axis, the liquid crystal lens comprising:

a first substrate having a first half region and a second half region, the first half region and the second half region being disposed on both sides of the optical axis, respectively;

a second substrate having a third half area and a fourth half area, the third half area and the fourth half area being respectively disposed at both sides of the optical axis, the third half area being opposite to the first half area, the fourth half area being opposite to the second half area;

a liquid crystal layer disposed between the first substrate and the second substrate;

a first electrode layer disposed between the first half region and the liquid crystal layer;

a first common electrode layer disposed between the second half region and the liquid crystal layer;

a second electrode layer disposed between the fourth half region and the liquid crystal layer, wherein the second electrode layer has the same structure as the first electrode layer;

a second common electrode layer disposed between the third half region and the liquid crystal layer, wherein the second common electrode layer has the same structure as the first common electrode layer;

The first electrode layer and the second electrode layer respectively comprise a plurality of first electrodes, the first electrodes in the first electrode layer are arranged at intervals by the edge of the liquid crystal lens along the optical axis and are divided into a plurality of groups, the first electrodes in the second electrode layer are arranged at intervals by the edge of the liquid crystal lens along the optical axis and are divided into a plurality of groups, each group of first electrodes has a preset electrode sampling rate, and the electrode sampling rate of the group close to the optical axis is larger than that of the group far away from the optical axis.

According to an aspect of the present invention, the plurality of first electrodes in the first electrode layer are divided into a plurality of regions, and the plurality of first electrodes in the second electrode layer are divided into a plurality of regions, the regions having a preset width;

each of said groups comprising at least one zone, different groups comprising the same or different numbers of zones;

in the same group: the electrode sampling rate is the same for each of the zones.

According to one aspect of the invention, the width of the region is

Wherein i is the number of sequences of the corresponding regions in the first electrode layer or the second electrode layer, and the number of sequences is counted from the region closest to the optical axis in the first electrode layer or the second electrode layer to the edge of the liquid crystal lens and is counted from 1; w1 is the width of the region of the first electrode layer or the second electrode layer closest to the optical axis.

According to one aspect of the present invention, a third electrode layer is disposed between the first electrode layer and the liquid crystal layer, and a first dielectric layer is disposed between the first electrode layer and the third electrode layer; a fourth electrode layer is arranged between the second electrode layer and the liquid crystal layer, and a second dielectric layer is arranged between the second electrode layer and the fourth electrode layer; wherein the third electrode layer and the fourth electrode layer have the same structure;

a plurality of groups of the first electrode layers: the group closest to the optical axis is a central group, and the other groups are expansion groups; a plurality of groups of the second electrode layers: the group closest to the optical axis is a central group, and the other groups are expansion groups;

the third electrode layer and the fourth electrode layer respectively comprise a plurality of second electrodes, the second electrodes are distributed between at least part of the groups and the liquid crystal layer, the second electrodes between the liquid crystal layer and one group and the first electrodes in the one group are alternately arranged in the first direction, the second electrodes are partially overlapped with the first electrodes adjacent to the second electrodes, and the first direction is perpendicular to the optical axis;

the first electrode is configured to output a driving voltage, and the second electrode is configured to output a coupling voltage by capacitive coupling with two first electrodes partially overlapped thereto.

According to one aspect of the invention, the plurality of second electrodes are distributed between each of the enlarged groups and the liquid crystal layer.

According to one aspect of the invention, the plurality of second electrodes are distributed between each of the groups and the liquid crystal layer.

According to one aspect of the invention, in the center group:

the overlapping width of each first electrode and the corresponding second electrode is the same; or alternatively, the process may be performed,

each first electrode has a different overlap width with the corresponding second electrode, and the overlap width of the first electrode close to the optical axis with the corresponding second electrode is larger than the overlap width of the first electrode far from the optical axis with the corresponding second electrode; or alternatively, the process may be performed,

the overlapping area ratio of each second electrode and the corresponding first electrode is the same.

According to an aspect of the present invention, the plurality of second electrodes are distributed between each of the enlarged groups and the liquid crystal layer, the second electrodes having a first pitch in the optical axis direction with the first electrodes in the enlarged groups;

the first electrodes in the central group are arranged in two layers, the first electrodes in the two layers are alternately arranged in a first direction, and the projections of the first electrodes in the two layers in the first direction are tangential; a dielectric layer is arranged between the first electrodes of the two layers; the first electrodes in the two layers have a second pitch in the optical axis direction, the second pitch being larger than the first pitch.

According to an aspect of the present invention, the plurality of first electrodes in the first electrode layer are disposed at equal intervals from the optical axis toward the edge of the first half region, and the plurality of first electrodes in the second electrode layer are disposed at equal intervals from the optical axis toward the edge of the fourth half region.

According to an aspect of the present invention, the liquid crystal lens further includes a circuit bus including a plurality of circuit branches, the plurality of circuit branches respectively providing different voltages, the number of the circuit branches being the same as the number of the first electrodes included in one region of the center group;

the center group: a plurality of first electrodes in each of the regions are in one-to-one correspondence with and electrically connected to the plurality of circuit branches;

in the expanded group: the first electrode is connected to a corresponding circuit branch in accordance with a target coupling voltage of a second electrode coupled thereto.

According to one aspect of the invention, the circuit bus further comprises a maximum voltage branch and/or a minimum voltage branch;

in the expanded group: the first electrode is connected with a corresponding circuit branch line, a maximum voltage branch line or a minimum voltage branch line according to the target coupling voltage of the second electrode coupled with the first electrode.

According to one aspect of the invention, the surface areas of the first electrodes in the same group are the same;

In the first electrode layer: the surface areas of the first electrodes in different groups are different, and the second electrode layers are as follows: the surface areas of the first electrodes in different groups are different;

the surface area of the first electrodes in the group close to the optical axis is smaller than the surface area of the first electrodes in the group far from the optical axis.

According to one aspect of the invention, in the same group: the line width of the first electrode close to the optical axis is larger than that of the first electrode far away from the optical axis;

two adjacent groups: the line width of the first electrode closest to the optical axis in the group away from the optical axis is larger than the line width of the first electrode farthest from the optical axis in the group close to the optical axis.

According to one aspect of the invention, a first liquid crystal alignment layer is arranged on one side, close to the first substrate, of the liquid crystal layer, and the first liquid crystal alignment layer is rubbed and aligned along the side, where the first common electrode layer is located, of the first electrode layer;

and a second liquid crystal alignment layer is arranged on one side of the liquid crystal layer, which is close to the second substrate, and the second liquid crystal alignment layer is rubbed and aligned along the side where the second common electrode layer is positioned and the side where the second electrode layer is positioned.

The invention also provides a preparation method of the liquid crystal lens, which comprises the following steps:

Forming a first electrode layer on a first half region of a first substrate, and forming a first common electrode layer on a second half region of the first substrate;

forming a second common electrode layer on a third half region of the second substrate, and forming a second electrode layer on a fourth half region of the second substrate;

arranging a spacer on the first substrate or the second substrate;

forming a liquid crystal layer on one of the first substrate or the second substrate;

forming a rubber frame on the other of the first substrate and the second substrate; and

combining the first substrate and the second substrate, enabling a first half area of the first substrate to be opposite to a third half area of the second substrate, enabling a second half area of the first substrate to be opposite to a fourth half area of the second substrate, and curing a rubber frame;

wherein the first common electrode layer has the same structure as the second common electrode layer, and the first electrode layer has the same structure as the second electrode layer; the first electrode layer and the second electrode layer respectively comprise a plurality of first electrodes, the first electrodes in the first electrode layer are arranged at intervals by the edge of the liquid crystal lens along the optical axis and are divided into a plurality of groups, the first electrodes in the second electrode layer are arranged at intervals by the edge of the liquid crystal lens along the optical axis and are divided into a plurality of groups, each group of first electrodes has a preset electrode sampling rate, and the electrode sampling rate of the group close to the optical axis is larger than that of the group far away from the optical axis.

According to one aspect of the invention, the preparation method further comprises:

forming a first dielectric layer and a third electrode layer on the first electrode layer; and

forming a second dielectric layer and a fourth electrode layer on the second electrode layer;

wherein, in the plurality of groups of the first electrode layer: the group closest to the optical axis is a central group, and the other groups are expansion groups; a plurality of groups of the second electrode layers: the group closest to the optical axis is a central group, and the other groups are expansion groups;

the third electrode layer and the fourth electrode layer have the same structure, each of the third electrode layer and the fourth electrode layer comprises a plurality of second electrodes, the second electrodes are distributed between at least part of the groups and the liquid crystal layer, the second electrodes between the liquid crystal layer and one group and the first electrodes in the one group are alternately arranged in the first direction, the second electrodes are partially overlapped with the first electrodes adjacent to the second electrodes, and the first direction is perpendicular to the optical axis;

According to one aspect of the invention, the plurality of second electrodes are distributed between each of the enlarged electrode resistances and the liquid crystal layer.

the first electrodes in the central group are arranged in two layers, the first electrodes in the two layers are alternately arranged in a first direction, and the projections of the first electrodes in the two layers in the first direction are tangential; the first electrodes in the two layers have a second pitch in the optical axis direction, the second pitch being larger than the first pitch.

forming a first liquid crystal alignment layer on the first substrate, and rubbing and aligning along the side where the first common electrode layer is located; and

and forming a second liquid crystal alignment layer on the second substrate, and rubbing and aligning along the side where the second common electrode layer is located and the side where the second electrode layer is located.

Compared with the prior art, the embodiment of the invention provides a liquid crystal lens and a preparation method thereof. The liquid crystal lens has a simple structure, the surfaces of all layers are flat, the alignment of liquid crystal molecules is easy, and the processing and the production are easy.

The plurality of first electrodes in the first electrode layer are divided into a plurality of groups, the plurality of first electrodes in the second electrode layer are divided into a plurality of groups, each group of first electrodes is provided with a preset electrode sampling rate, and the electrode sampling rate of the group close to the optical axis is larger than that of the group far away from the optical axis, so that the size of the liquid crystal lens can be larger.

The first electrode layer and the first common electrode layer are respectively arranged in the first half area and the second half area of the first substrate, and the second common electrode layer and the second electrode layer are respectively arranged in the third half area and the fourth half area of the second substrate, so that the optical path difference distribution of the liquid crystal lens can be effectively improved, and the problem of decentration of the liquid crystal lens is solved.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:

fig. 1 shows a cross-sectional view of a liquid crystal lens 100 according to an embodiment of the present invention;

FIGS. 2A-2C show schematic diagrams of a first stage according to one embodiment of the invention;

fig. 3 shows a cross-sectional view of a liquid crystal lens 200 according to an embodiment of the invention;

FIG. 4 shows a schematic diagram of the connection of a first electrode to a circuit bus according to one embodiment of the invention;

fig. 5 shows a schematic diagram of a liquid crystal lens 300 according to an embodiment of the invention;

fig. 6 shows a schematic diagram of a liquid crystal lens 400 according to an embodiment of the invention;

fig. 7 shows an optical path difference distribution curve and a standard curve of the liquid crystal lens 100;

fig. 8 shows a flowchart of a method of manufacturing a liquid crystal lens according to an embodiment of the present invention;

FIG. 9 shows an optical path difference distribution curve of a conventional equal-height Fresnel liquid crystal lens;

fig. 10 shows a prior art optical path difference distribution curve and a standard curve of a liquid crystal lens having a ring electrode.

Detailed Description

Hereinafter, only certain exemplary embodiments are briefly described. As will be recognized by those of skill in the pertinent art, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be fixedly connected, detachably connected, or integrally connected, and may be mechanically connected, electrically connected, or may communicate with each other, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is less level than the second feature.

The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

The embodiments of the present invention will be described below with reference to the accompanying drawings, and it should be understood that the embodiments described herein are for illustration and explanation of the present invention only, and are not intended to limit the present invention.

Fig. 1 shows a cross-sectional view of a liquid crystal lens 100 according to one embodiment of the present invention, which is described in detail below in conjunction with fig. 1.

As shown in fig. 1, the liquid crystal lens 100 has an optical axis, which may be located at the center of the liquid crystal lens 100. The liquid crystal lens 100 includes a first substrate 110, a second substrate 120, a liquid crystal layer 130, a first common electrode layer 140, a second common electrode layer 150, a first electrode layer 161, and a second electrode layer 162, wherein the first substrate 110 and the second substrate 120 are transparent substrates (e.g., may be glass substrates), the first substrate 110 has a first half area 111 and a second half area 112, the first half area 111 and the second half area 112 are respectively located at two sides of an optical axis, the second substrate 120 has a third half area 121 and a fourth half area 122, the third half area 121 and the fourth half area 122 are respectively located at two sides of the optical axis, and the first half area 111 is opposite to the third half area 121, and the second half area 112 is opposite to the fourth half area 122. The liquid crystal layer 130 is disposed between the first substrate 110 and the second substrate 120. The first common electrode layer 140 and the second common electrode layer 150 have the same structure, and the first common electrode layer 140 and the second common electrode layer 150 may be surface electrodes, wherein the first common electrode layer 140 is disposed between the second half-section 112 and the liquid crystal layer 130, and the second common electrode layer 150 is disposed between the third half-section 121 and the liquid crystal layer 130. The first electrode layer 161 and the second electrode layer 162 have the same structure, wherein the first electrode layer 161 is disposed between the first half region 111 and the liquid crystal layer 130, the second electrode layer 162 is disposed between the fourth half region 122 and the liquid crystal layer 130, and specifically, the first electrode layer 161 and the second electrode layer 162 respectively include a plurality of first electrodes 163, the plurality of first electrodes 163 in the first electrode layer 161 are disposed at intervals from the optical axis to the edge of the liquid crystal lens 100 and divided into a plurality of groups, and similarly, the plurality of first electrodes 163 in the second electrode layer 162 are disposed at intervals from the optical axis to the edge of the liquid crystal lens 100 and divided into a plurality of groups.

As shown in fig. 2A, 2B, and 2C, the first electrode 163 may be a semicircular ring electrode, specifically, the first electrode 163 closest to the optical axis in the first electrode layer 161 is semicircular, and the other first electrodes 163 are semicircular, for example, each takes the optical axis as a center. Similarly, the first electrode 163 closest to the optical axis in the second electrode layer 162 is semicircular, and the other first electrodes 163 are semicircular, for example, all take the optical axis as the center.

As shown in fig. 1, each set of the first electrodes 163 has a preset electrode sampling rate (the electrode sampling rate refers to the number of the first electrodes 163 contained in each provided wavelength optical path difference of the liquid crystal lens, and the electrode sampling rate is greater than zero). In the first electrode layer 161 and the second electrode layer 162: the electrode sampling rates of the groups at the same distance from the optical axis are the same, for example, the electrode sampling rate of the first group in the first electrode layer 161 is equal to the electrode sampling rate of the first group in the second electrode layer 162, and the electrode sampling rate of the second group in the first group is equal to the electrode sampling rate of the second group in the second electrode layer 162. In the first electrode layer 161 and the second electrode layer 162: the electrode sampling rate of the group close to the optical axis is greater than the electrode sampling rate of the group far from the optical axis. For example, as shown in fig. 1, a first group has a first electrode sampling rate, a second group has a second electrode sampling rate, and a third group has a third electrode sampling rate, where the first electrode sampling rate > the second electrode sampling rate > the third electrode sampling rate. Although only three groups of the first electrode layer 161 and three groups of the second electrode layer 162 are shown in fig. 1, the present invention is not limited thereto and may be arranged in two or more groups according to the limit of the process or actual production needs. By gradually decreasing the electrode sampling rate among the plurality of groups, the width of the first electrode 163 can be controlled within a desired range, so that the processable size range of the liquid crystal lens 100 can be enlarged. By providing the first electrode layer 161 and the first common electrode layer 140 in the first half region 111 and the second half region 112 of the first substrate 110, and providing the second common electrode layer 150 and the second electrode layer 162 in the third half region 121 and the fourth half region 122 of the second substrate 120, respectively, the optical path difference distribution of the liquid crystal lens 100 can be effectively improved, and the problem of decentration of the liquid crystal lens can be corrected.

According to an embodiment of the present invention, as shown in fig. 1 and 2, the liquid crystal lens 100 may further include a first liquid crystal alignment layer 170 and a second liquid crystal alignment layer 180, wherein the first liquid crystal alignment layer 170 and the second liquid crystal alignment layer 180 are disposed adjacent to the liquid crystal layer 130, the first liquid crystal alignment layer 170 is disposed on a side of the liquid crystal layer 130 adjacent to the first substrate 110, the first liquid crystal alignment layer 170 is rubbed and aligned along a side of the first common electrode layer 140 adjacent to the first electrode layer 161, the second liquid crystal alignment layer 180 is disposed on a side of the liquid crystal layer 130 adjacent to the second substrate 120, and the second liquid crystal alignment layer 180 is rubbed and aligned along a side of the second common electrode layer 150 adjacent to the second electrode layer 162. In other embodiments, the first liquid crystal alignment layer 170 may be rubbed along the side of the first electrode layer 161 where the first common electrode layer 140 is located, and the second liquid crystal alignment layer 180 may be rubbed along the side of the second electrode layer 162 where the second common electrode layer 150 is located.

According to an embodiment of the present invention, as shown in fig. 1, the plurality of first electrodes 163 in the first electrode layer 161 are divided into a plurality of regions, and the plurality of first electrodes 163 in the second electrode layer 162 are divided into a plurality of regions, each region including one or more first electrodes 163 and having a preset width. The width of the zone may be, for example

Wherein i is the number of the corresponding regions in the first electrode layer 161 or the second electrode layer 162, and the number of the corresponding regions is counted from the region closest to the optical axis in the first electrode layer 161 or the second electrode layer 162 to the edge of the liquid crystal lens 100 and counted from 1; w1 is the width of the region closest to the optical axis in the first electrode layer 161 or the second electrode layer 162 (i.e., the width of the region of the first electrode layer 161 or the second electrode layer 162 having an arrangement number of 1), and the calculation of W1 will be described in detail later. Each group contains at least one zone, and different groups contain the same or different numbers of zones. In the same group, the electrode sampling rate of each region is the same, and for one region, different voltages are applied to different first electrodes 163 in the region, so that the liquid crystal opposite to the region can be deflected by different angles to form one lens region of the fresnel liquid crystal lens.

According to one embodiment of the present invention, as shown in fig. 1, the surface areas of the first electrodes 163 in the same group are the same, the surface areas of the first electrodes 163 in different groups in the first electrode layer 161 are different, and as such, the surface areas of the first electrodes 163 in different groups in the second electrode layer 162 are different. The surface area of the first electrode 163 in the group close to the optical axis is smaller than the surface area of the first electrode 163 in the group far from the optical axis, for example, as shown in fig. 1, in the first electrode layer 161: the surface area of the first electrode 163 in the first group < the surface area of the first electrode 163 in the second group < the surface area of the first electrode 163 in the third group, wherein the surface area of the first electrode 163 refers to the area including the corresponding first electrode 163 and the gap within the preset range beside the first electrode 163, and in the present embodiment, the surface area of the first electrode 163 refers to the area including the corresponding first electrode 163 and the half gap inside the first electrode 163 and the half gap outside the first electrode 163; in other embodiments, the surface area of the first electrode 163 refers to an area including the corresponding first electrode 163 and the gap inside (or outside) the first electrode 163.

According to an embodiment of the present invention, as shown in fig. 1, a plurality of first electrodes 163 in the first electrode layer 161 are disposed at equal intervals from the optical axis toward the edge of the first half area 111. The plurality of first electrodes 163 in the second electrode layer 162 are disposed at equal intervals from the light axis to the edge of the fourth half area 122. Regarding the gap between adjacent first electrodes 163: when the gap is small, for example, less than 3 μm, there is no significant effect on the display effect of the liquid crystal lens, but if the gap is further reduced, there is little (or no) improvement in the display effect of the liquid crystal lens 100, but instead the processing difficulty is increased; when the gap is large, the display effect of the liquid crystal lens 100 is adversely affected; the size of the gap will therefore generally be chosen to be a value that does not affect the effect but can be processed; the equidistant arrangement of the first electrodes 163 may facilitate the design and processing of the liquid crystal lens.

According to one embodiment of the present invention, as shown in fig. 1, in the same group, the line width of the first electrode 163 close to the optical axis (i.e., the radial width of the ring electrode) is larger than the line width of the first electrode 163 far from the optical axis. Specifically, in the above-described preferred embodiment, since the surface areas of the first electrodes 163 in the same group are the same, in the same group: the larger the difference between the outer diameter and the inner diameter of the first electrode 163 closer to the optical axis, the smaller the difference between the outer diameter and the inner diameter of the first electrode 163 farther from the optical axis, and accordingly, the larger the line width of the first electrode 163 closer to the optical axis, and the smaller the line width of the first electrode 163 farther from the optical axis.

As shown in fig. 1, in the adjacent two groups, the line width of the first electrode 163 closest to the optical axis in the group distant from the optical axis is larger than the line width of the first electrode 163 farthest from the optical axis in the group close to the optical axis. The first electrode 163 in the liquid crystal lens 100 is processed as follows: taking fig. 1 as an example, in a first group range (1-m-1 region), using a first electrode sampling rate, the line width of the first electrode 163 gradually decreases along a first direction according to an equal area rule (the surface areas of the first electrodes 163 in the same group are the same) until the line width of the first electrode 163 at the extreme edge just meets the design or processing requirement; when the size of the lc lens 100 is continuously increased according to such area rules, the line width of the first electrode 163 will not meet the design or processing requirements, and thus the electrode sampling rate (using the second electrode sampling rate) is reduced within the second set of ranges (m-n-1 region) so as to increase the surface area of the first electrode 163, i.e., the width of the first electrode 163; when the second electrode sampling rate is used to a certain size, the line width of the first electrode 163 cannot meet the design or processing requirements, so that the electrode sampling rate (the third electrode sampling rate is used) is continuously reduced in the third group range (n-i region) so as to further increase the surface area of the first lens, that is, the width of the first electrode 163 is increased, and the lens size can be further enlarged. Similarly, by gradually decreasing the electrode sampling rate between the groups, the width of the first electrode 163 can be controlled within a desired range, thereby expanding the processable size range of the liquid crystal lens 100.

In the first electrode layer 161: since the electrode sampling rate is different for each group, the number of first electrodes 163 contained in the regions in different groups is different, and the voltages required to be distributed by the first electrodes 163 in different groups when forming the same focal length are different, in some embodiments, each first electrode 163 can be provided with the required voltage by a power supply circuit; the same is true in the second electrode layer 162, and the description is omitted herein, and the first electrode 163 in the second electrode layer 162 and the first electrode 163 in the first electrode layer 161 may use the same power supply circuit.

Fig. 3 shows a cross-sectional view of a liquid crystal lens 200 according to an embodiment of the present invention, as shown in fig. 3, the liquid crystal lens 200 is different from the liquid crystal lens 100 in that: a third electrode layer 191 is provided between the first electrode layer 161 and the liquid crystal layer 130, and a first dielectric layer (not shown) is provided between the first electrode layer 161 and the third electrode layer 191. A fourth electrode layer 192 is disposed between the second electrode layer 162 and the liquid crystal layer 130, and a second dielectric layer (not shown) is disposed between the second electrode layer 162 and the fourth electrode layer 192. For convenience of explanation, the first electrode layer 161 is selected from a plurality of groups: the group closest to the optical axis is called the center group, and the other groups are called the enlarged groups; the second electrode layer 162 is formed of a plurality of groups: the group closest to the optical axis is called the center group, and the other groups are called the enlarged groups. The third electrode layer 191 and the fourth electrode layer 192 have the same structure, and the third electrode layer 191 and the fourth electrode layer 192 each include a plurality of second electrodes 193, and the second electrodes 193 are disposed between at least a part of the groups and the liquid crystal layer 130, for example, in the liquid crystal lens 200: the plurality of second electrodes 193 are distributed between each enlarged group and the liquid crystal layer 130 (i.e., the plurality of second electrodes 193 in the third electrode layer 191 are distributed between each enlarged group of the first electrode layer 161 and the liquid crystal layer 130, and the plurality of second electrodes 193 in the fourth electrode layer 192 are distributed between each enlarged group of the second electrode layer 162 and the liquid crystal layer 130). The second electrodes 193 located between the liquid crystal layer 130 and one group and the first electrodes 163 in this group are alternately arranged in a first direction, the second electrodes 193 and the first electrodes 163 adjacent thereto are partially overlapped, the first direction is perpendicular to the optical axis, and in this embodiment, the first direction is directed from the optical axis to the edge of the liquid crystal lens 200. Wherein the first electrode 163 is configured to output a driving voltage, the second electrode 193 is used as a floating electrode (f l oat i ng), the second electrode 193 can output a coupling voltage through capacitive coupling with the two first electrodes 163 overlapped with the second electrode, and the magnitude of the coupling voltage is related to the driving voltage output from the two first electrodes 163 coupled with the corresponding second electrode 193 and also related to the overlapping area of the corresponding second electrode 193 and the corresponding first electrode 163. The driving of the liquid crystal lens 200 can be simplified by providing the third electrode layer 191 and the fourth electrode layer 192 and using the second electrode 193 as a floating electrode. By providing the first electrode layer and the fourth electrode layer 192, the first electrode 163 and the second electrode 193 can provide more voltage difference on both sides of the liquid crystal layer 130 in cooperation with the corresponding first common electrode layer 140 or second common electrode layer 150, thereby improving the display effect of the liquid crystal lens 200; wherein, at the position where the second electrode 193 is disposed, the second electrode 193 and the first common electrode layer 140 or the second common electrode layer 150 provide a voltage difference to the liquid crystal layer 130; at a position where the second electrode 193 is not disposed (e.g., at a distance between two adjacent second electrodes 193 in a range where the center group is located), the first electrode 163 and the first common electrode layer 140 or the second common electrode layer 150 provide a voltage difference to the liquid crystal layer 130. The thickness of the first dielectric layer and the second dielectric layer may be as small as possible, so that the second electrode 193 is as close to the first electrode 163 as possible, thereby improving the coupling effect between the second electrode 193 and the first electrode 163.

According to an embodiment of the present invention, the liquid crystal lens 200 further includes a circuit bus including a plurality of circuit branches, the plurality of circuit branches respectively providing different voltages, the number of circuit branches being the same as the number of first electrodes included in one region of the center group. In the central group, the first electrodes in each region are in one-to-one correspondence with and electrically connected to the circuit branches; in the expanded set, the first electrode connects the corresponding circuit branch according to the target coupling voltage of the second electrode 193 to which it is coupled.

Fig. 4 shows a schematic diagram of connection of the first electrode to the circuit bus line according to an embodiment of the present invention, and for convenience of explanation and understanding, only 3 groups of the first electrode layer 161 are shown in fig. 4, and the number of the first electrodes included in each group is not limited thereto, provided that each group contains 2 regions, and the number of the first electrodes included in each region is at most 10, in practice, the number of groups, the number of the regions included in each group, and the number of the first electrodes included in each region are not limited thereto. As shown in fig. 4, since the first group (center group) has the highest electrode sampling rate, the first electrodes are included in the region of the first group in the largest number, and the number of circuit branches for supplying power to the first electrodes in the first group is equal to the number of voltages required to be supplied to the first electrodes in the first group range (i.e., equal to the number of first electrodes in a single region of the first group), and since the electrode sampling rate is reduced, the number of voltages required to be supplied to the first electrodes in the second group (enlarged group) and the third group (enlarged group) ranges is smaller than the number of voltages required to be supplied to the first electrodes in the first group range, and the maximum and minimum values of voltages required to be supplied to the first electrodes in the second group and the third group ranges are generally within the maximum and minimum voltage ranges required to be supplied to the first electrodes in the first group range.

Assuming that the number of the first electrodes (163 a to 163j in fig. 4) included in each region in the first group is 10, the number of voltages to be supplied to the first electrodes 163a to 163j in the first group is 10, the circuit bus includes 10 circuit branches, and the 10 circuit branches supply voltages, respectively

V1, V2, …, V9, V10, where V1 is the smallest, V10 is the largest, and the voltage monotonically increases (here, by way of example only, and not by way of limitation, V1-V10 voltage monotonically decreases in other embodiments), the first electrodes 163 a-163 j within the first set of ranges being connected to respective circuit branches. The number of the first electrodes (163 a 'to 163h' in fig. 4) included in each region in the second group range is 8, the first electrodes 163a 'to 163h' in the second group range are respectively connected to the corresponding circuit branch lines, and the first electrodes 163a 'to 163h' in each region in the second group range are respectively coupled to the corresponding second electrodes 193, so that the 7 second electrodes 193 corresponding to the corresponding regions respectively output coupling voltages V1 'to V7'. For example, when the desired target coupling voltage V1' is between V1 and V3, then the first electrode 163a ' is connected to the circuit branch V1, the first electrode 151b ' is connected to the circuit branch V3, and the coupling voltage V1' is obtained by overlapping the first electrodes 163a ', 163b ' with the corresponding second electrodes 193 in an appropriate area, where V1 < V1' < V3. The number of the first electrodes (163 a "to 163e" in fig. 4) included in each of the regions in the third group range is 5, the first electrodes 163a "to 163e" in the third group range are connected to the respective circuit branch lines, and the first electrodes 163a "to 163e" in each of the regions in the third group range are coupled to the respective second electrodes 193, so that the 4 second electrodes 193 corresponding to the respective regions output coupling voltages V1 "to V4", respectively. For example, when the coupling voltage V1 "is between V3 and V4, then the first electrode 163a" is connected to the circuit branch V3, the first electrode 163b "is connected to the circuit branch V4, and the coupling voltage V1" is obtained by overlapping the coupling of the corresponding second electrode 193 and the first electrode 163a ", 163b" with an appropriate area, where V3 < V1 "< V4; for another example, when the coupling voltage V1 "is between V4 and V6, the first electrode 163b" is connected to the circuit branch V4, the first electrode 163c "is connected to the circuit branch V6, and the coupling voltage V2" is obtained by overlapping the coupling of the corresponding second electrode 193 and the first electrode 163b ", 163c" with an appropriate area, where V4 < V2 "< V6.

According to one embodiment of the invention, the circuit bus may also comprise a maximum voltage branch Vmax and/or a minimum voltage branch vmin, as shown in fig. 4. In the expanded group, the first electrode may connect the corresponding circuit branch, maximum voltage branch Vmax, or minimum voltage branch vmin according to the target coupling voltage of the second electrode 193 to which it is coupled; in particular, when the maximum voltage value required to be provided by a first electrode in an expanded group is greater than that required by a first electrode in a central group, the corresponding first electrode in the expanded group may be connected to a maximum voltage branch Vmax; when the voltage minimum required to be provided by a first electrode in an enlarged group is smaller than the voltage minimum required to be provided by a first electrode in a central group, the corresponding first electrode in the enlarged group may be connected to the minimum voltage branch Vmi n.

Fig. 5 shows a cross-sectional view of a liquid crystal lens 300 according to an embodiment of the present invention, as shown in fig. 5, the liquid crystal lens 300 is different from the liquid crystal lens 200 in that: the plurality of second electrodes 193 are distributed between each group and the liquid crystal layer 130, that is, the plurality of second electrodes 193 in the third electrode layer 191 are distributed between each group (center group, enlarged group) of the first electrode layer 161 and the liquid crystal layer 130, and the plurality of second electrodes 193 in the fourth electrode layer 192 are distributed between each group (center group, enlarged group) of the second electrode layer 162 and the liquid crystal layer 130. By disposing the second electrode 193 in a range corresponding to the center group, more voltage difference can be provided at both sides of the liquid crystal layer 130, further improving the display effect of the liquid crystal lens.

According to one embodiment of the present invention, as shown in fig. 5, in the center group, the overlapping width of each first electrode 163 and the corresponding second electrode 193 is the same, for example, the overlapping width of the first electrode 163 and the corresponding second electrode 193 may be 5 μm (3 μm, 6 μm, etc. in other embodiments, the present invention is not limited thereto); alternatively, the overlapping area ratio of each first electrode 163 and the corresponding second electrode 193 is the same, for example, the overlapping area ratio of the first electrode 163 and the corresponding second electrode 193 may be 25% (in other embodiments, 20%, 30%, etc., the invention is not limited thereto, the overlapping area ratio is the overlapping area/the first electrode area), or the overlapping width of each first electrode 163 and the corresponding second electrode 193 is different, and the overlapping width of the first electrode 163 and the corresponding second electrode 193 near the optical axis is larger than the overlapping width of the first electrode 163 and the corresponding second electrode 193 far from the optical axis, that is, the overlapping width of the first electrode 163 and the second electrode 193 gradually decreases from the optical axis to the edge of the liquid crystal lens 300. Wherein the second electrodes 193 are arranged according to the same overlapping width, all the second electrodes 193 need not be shorted as the limit/maximum value of the line width (i.e. the second electrodes 193 cannot be wider, otherwise short-circuiting occurs), so that the overlapping width of the second electrodes 193 and the first electrodes 163 may only occupy a small part of the corresponding first electrodes 163 (such as the first electrodes 163 closest to the optical axis), and the coupling effect between the second electrodes 193 and the first electrodes 163 is limited; however, the arrangement of the second electrodes 193 according to the same overlapping area ratio does not have such a problem, because the overlapping area ratio is the same, the line widths of the second electrodes 193 may be different (the larger the overlapping area of the second electrodes 193 and the first electrodes 163 is, the larger the line widths of the corresponding second electrodes 193 are), and the second electrodes 193 and the first electrodes 163 may have good coupling effect, so that the arrangement of the second electrodes 193 according to the same overlapping area ratio has good effect; similarly, it is also preferable to provide the second electrode 193 in a regular manner in which the overlapping width gradually decreases from the optical axis to the edge of the liquid crystal lens. The second electrode 193 determines the line width according to the overlapping width or overlapping area ratio with the corresponding first electrode 163 in the range corresponding to the center group, so that the processing of the second electrode layer 162 can be more convenient, and the line width of the second electrode 193 is determined according to the coupling voltage required to be output in the range corresponding to the expanded group.

Fig. 6 shows a cross-sectional view of a liquid crystal lens 400 according to an embodiment of the present invention, as shown in fig. 6, the liquid crystal lens 400 is different from the liquid crystal lens 200 in that: the first electrodes 163 in the center group are arranged in two layers, and the first electrodes 163 in the two layers are alternately arranged in the first direction. Preferably, the tangents of projections of two first electrodes 163 in the central group, adjacent in the first direction, onto a first plane (the first plane being perpendicular to the optical axis) do not overlap, preferably form tangents, i.e. no gap between them. In the liquid crystal lens 400, two first electrodes 163 in the first electrode layer 161 and the second electrode 193 in the third electrode layer 191 are disposed in different layers, and the layers are separated and insulated by a first dielectric layer; preferably, as shown in fig. 6, the layer (the third electrode layer 191 or the fourth electrode layer 192) where the second electrode 193 is located between the two layers of the first electrodes 163 (the second electrode 193 and the first electrodes 163 in the corresponding expanded group have a first pitch in the optical axis direction, and the two layers of the first electrodes 163 have a second pitch therebetween, and the second pitch is larger than the first pitch), so that the second electrode 193 is located as close to the first electrode 163 coupled thereto as possible. The problem of weak process capability can be well solved by dividing the first electrode 163 in the center group into two layers. Under the condition of weak process capability, the gap between adjacent electrodes is larger, so that the display effect of the liquid crystal lens is affected; if the electrodes are distributed in the same layer with smaller gaps, the risk of short-circuiting between adjacent electrodes increases. The first electrode 163 is divided into two layers, so that the gap between the first electrodes of the same layer can be increased, and the first electrodes of the same layer are not easy to short; meanwhile, the upper layer and the lower layer of the first electrode are separated by the dielectric layer, so that short circuit is not easy to occur; the electric field is continuously transited in the first direction, so that the problem of weak processing capability can be well solved. The following illustrates the effects of the embodiments of the present invention.

The basic principle of the Fresnel liquid crystal lens is as follows: under the action of the applied electric field, a gradient distribution of non-uniform refractive index is formed in the liquid crystal layer 130. The focal length f of the fresnel liquid crystal lens is:

wherein: r is the radius of the fresnel liquid crystal lens; Δn is the birefringence of the liquid crystal material; d is the thickness of the liquid crystal layer 130 and q is the number of fresnel lens zones. Optical path difference distribution curve phi=r of Fresnel liquid crystal lens ² /(2f=q) =Δn×d, where Φ is the liquid crystal lens optical path difference, and if the thickness of the fresnel liquid crystal lens cell can provide an optical path difference of pλ (p is the wave number), pλ=Φ=Δn×d.

Calculation of electrode sampling rate: (1) For a certain liquid crystal lens product, λ is known from the product of instrumentally measurable Δn and d (Δn×d), then p can be calculated according to the above formula; (2) For a certain liquid crystal lens product, the number N of first electrodes (driving electrodes) contained in a certain region can be measured by the device, so that the electrode sampling rate fs=n/p in the region can be calculated. It should be noted that, the electrode sampling rate obtained by the calculation method is obtained by reverse engineering and is not used for defining the electrode sampling rate in the application; the electrode sampling rate in the application is set according to engineering processing limit or actual requirement. ' s of

The line width calculation process for the first electrode 163 in the

liquid crystal lens

100, 200, 300, 400 is as follows (taking the first electrode 163 in the first electrode layer 161 as an example):

(1) Radius of central first electrode (first electrode 163 closest to optical axis)

Wherein lambda is the wavelength of incident light, f is the focal length, fs1 is the firstElectrode sampling rate for a group.

The x-th first electrode 163 (x is the number of the first electrode 163 and is ordered from the optical axis to the edge of the liquid crystal lens) in the first group has a radius

From this, the width of each first electrode 163 can be calculated.

The number of first electrodes 163 in each region in the first group is determined by the electrode sampling rate and the cell thickness of the liquid crystal lens (assuming that the cell thickness of the liquid crystal lens provides an optical path difference of pλ, p is the wave number), and in the first group: the number of first electrodes 163 in each region is n1=p×fs1;

width of the first region (region with rank number 1)

Radius r1=w1 of the first zone, area s1=piw12/2 of the first zone;

width of the second zone (zone with rank number 2)

Outer circle radius of second zone

The area s2=piw12/2 of the second region;

……

width of the ith zone (zone of rank number i)

The outer circle radius ri=w1+w2+ … … +wi of the i-th region, and the area si=piw12/2 of the i-th region.

The area of each zone is equal.

The electrode sampling rate of the first group is determined, the number of regions contained within the first group is dependent upon the processing limits of the minimum width being met by all of the electrodes within the regions, and the spacing between each of the first electrodes 163 within each group is equal.

(2) Assuming that the first group comprises 1-m-1 regions, the area of the first group is (m-1) pi W12/2, then the secondThe group starts from zone m, width of zone m

The surface area Sm of the first m zone in the second group=piw12/2.

(3) The electrode sampling rate fs2 of the second group is determined, and the number of first electrodes 163 per region in the second group is n2=p×fs2.

(4) Since the surface area of each first electrode 163 in the same group is the same, then the surface area of the first electrode 163 in the second group (the first electrode 163 closest to the optical axis in the second group) =sm/(2×n2) =pi W12/(2×n2);

assuming that the outer circumferential radius of the first electrode 163 in the second group is r1', the area of the outer circumference of the first electrode 163 in the second group= ((m-1) pi w12+sm/n 2)/2= ((m-1+1/n 2) pi w12)/2=pi r1'2/2, and r1' can be found; the circular area of the second first electrodes 163 in the second set= ((m-1) piw12+2sm/n 2)/2=pi×r2'2/2, and r2' can be found, and so on, the radius of each first electrode 163 in the first m-zone of the second set can be found. The radius calculation method of the first electrode 163 in the region after the second group m of regions is the same as the radius calculation method of the ring of the first electrode 163 in the second group m of regions, and will not be described here.

(5) The electrode sampling rate of the second set is determined, the number of regions contained within the second set is dependent upon the processing limits of the minimum width being met by all of the electrodes within the regions, and the spacing between each of the first electrodes 163 within each set is equal.

(6) The method for calculating the radius of the ring of the first electrode 163 in the other groups (the third group and the fourth group … …) is the same as the method for calculating the radius of the ring of the first electrode 163 in the second group, and will not be described here.

As shown in fig. 1, assuming that the cell thickness of the liquid crystal lens can provide an optical path difference of 10λ (λ= 543.5 nm), the focal length f of the liquid crystal lens is 1000mm, and the electrode sampling rate (first electrode sampling rate) fs1 of the first group is 5, the number n1 of electrodes contained in each region in the first group is 10×5=50. Radius of central first electrode (first electrode 163 closest to optical axis)

The width of the first region (region with an order of 1, the order number counted from the region closest to the optical axis to the edge of the liquid crystal lens and counted from 1)>

When the number of the first electrodes 163 is 277, the line width of the first electrodes 163 reaches a limit value of 10 μm, and the maximum radius of the liquid crystal lens is about 7.7mm, as shown in table 1, assuming that the width of the gap between the adjacent first electrodes 163 is 4 μm and the achievable minimum width of the first electrodes 163 is 10 μm. It is apparent that when the electrode sampling rate is 5, the line width of a part of the first electrode 163 in the sixth region (the region of the order number of 6) will not be achievable, and thus the first region to the fifth region (the region of the order number of 1 to 5) can be regarded as the first group, and the sixth region can be classified into the second group. The electrode sampling rate of the second group (the second electrode sampling rate) may be reduced to 4 (the electrode sampling rate may also be set to a decimal according to actual needs, for example, 4.5), and then the number of electrodes n2 contained in each region in the second group is 10×4=40, and the 40 first electrodes 163 are divided according to the equal area rule, so that the line widths of all the first electrodes 163 in the sixth region may be adjusted to be greater than 10. With the first electrode sampling rate, the line width of a part of the first electrode 163 in the sixth region will not meet design or processing requirements, while with the sixth region divided into the second group and with the second sampling rate, the line width of the first electrode 163 in the sixth region will meet requirements, and the size of the liquid crystal lens is increased to about 8.1mm. Similarly, the size of the liquid crystal lens can be further increased by further reducing the electrode sampling rate. / >

TABLE 1

Fig. 7 shows an optical path difference distribution curve and a standard curve of one of the liquid crystal lenses 100/200/300/400 in the above embodiment, such as the liquid crystal lens 100 (the thickness of the liquid crystal layer 130 is 65 μm, and the liquid crystal material Δn=0.3), and in fig. 7, only the center of the lens, i.e., two first-area optical path differences (λ= 543.5 nm) are extracted to compare the symmetry of the optical path differences with the standard curve. As shown in fig. 7, the optical path difference distribution curve of the liquid crystal lens 100 has good symmetry with respect to the geometric center, and the optical path difference distribution of the liquid crystal lens is significantly improved compared with that of the liquid crystal lens shown in fig. 10, so that the problem of decentration of the liquid crystal lens can be corrected.

Compared with the prior art, the

liquid crystal lenses

100, 200, 300 and 400 provided by the embodiment of the invention have the advantages that the structure is simple, the surfaces of all layers are flat, the alignment of liquid crystal molecules is easy, the processing and the production are easy, the size can be larger, the optical path difference distribution of the liquid crystal lenses is effectively improved, and the problem of the eccentricity of the liquid crystal lenses is solved.

Fig. 8 illustrates a method of manufacturing a liquid crystal lens according to an embodiment of the present invention, which is described in detail below with reference to fig. 8.

The method of manufacturing the liquid crystal lens includes the following steps, which are described in detail below, respectively.

In step S410: a first electrode layer is formed on a first half of the first substrate, and a first common electrode layer is formed on a second half of the first substrate.

In step S420: a second electrode layer is formed on a third half of the second substrate, and a second common electrode layer is formed on a fourth half of the second substrate.

The first common electrode layer has the same structure as the second common electrode layer, the formation of the first common electrode layer includes disposing the surface electrode in the second half region, and the formation of the second common electrode layer includes disposing the surface electrode in the third half region. The first electrode layer and the second electrode layer have the same structure, the first electrode layer and the second electrode layer respectively comprise a plurality of first electrodes, the first electrodes in the first electrode layer are arranged at intervals from the optical axis to the edge of the liquid crystal lens and are divided into a plurality of groups, and similarly, the first electrodes in the second electrode layer are also arranged at intervals from the optical axis to the edge of the liquid crystal lens and are divided into a plurality of groups. Each group of first electrodes has a preset electrode sampling rate (the electrode sampling rate refers to the number of first electrodes contained in each wavelength optical path difference, and the electrode sampling rate is greater than zero). In the first electrode layer and the second electrode layer: the electrode sampling rates of the groups at the same distance from the optical axis are the same, e.g. the electrode sampling rate of a first group of the first electrode layers is equal to the electrode sampling rate of a first group of the second electrode layers, the electrode sampling rate of a second group of the first group is equal to the electrode sampling rate of a second group of the second electrode layers. In the first electrode layer and the second electrode layer: the electrode sampling rate of the group close to the optical axis is greater than the electrode sampling rate of the group far from the optical axis. The first electrode may be a semicircular electrode, specifically, a first electrode closest to the optical axis in the first electrode layer is semicircular, and other first electrodes are semicircular, for example, all take the optical axis as a center; similarly, the first electrode closest to the optical axis in the second electrode layer is semicircular, and the other first electrodes are semicircular, for example, all take the optical axis as the center of a circle.

In step S430: spacers are disposed on the first substrate or the second substrate. Here, for example, a spacer may be disposed on a side of the first substrate where the first electrode layer and the first common electrode layer are provided.

In step S440: a liquid crystal layer is formed on one of the first substrate and the second substrate. For example, the liquid crystal layer may be formed on a side of the first substrate where the first electrode layer and the first common electrode layer are provided.

In step S450: and forming a rubber frame on the other of the first substrate and the second substrate. For example, a glue frame may be formed on a side of the second substrate where the second electrode layer and the second common electrode layer are disposed.

In step S460: combining the first substrate and the second substrate, enabling the first half area of the first substrate to be opposite to the third half area of the second substrate, enabling the second half area of the first substrate to be opposite to the fourth half area of the second substrate, and solidifying the rubber frame.

The preparation method of the liquid crystal lens can further comprise the following steps:

step S470: forming a first dielectric layer and a third electrode layer on the first electrode layer; and

step S480: a second dielectric layer and a fourth electrode layer are formed on the second electrode layer.

Step S470 may be performed simultaneously with step S410, or may be performed after step S410 is completed, according to actual circumstances. Step S480 may be performed simultaneously with step S420 or after step S420 is completed, depending on the actual situation. The third electrode layer and the fourth electrode layer have the same structure, the third electrode layer and the fourth electrode layer respectively comprise a plurality of second electrodes, the second electrodes are arranged between at least part of the groups and the liquid crystal layer (preferably, the plurality of second electrodes are distributed between each expansion group and the liquid crystal layer, or the plurality of second electrodes are distributed between each expansion group and the liquid crystal layer, the first electrodes in the second electrodes and the expansion groups have a first interval in the optical axis direction, the first electrodes in the central group are arranged into two layers, the first electrodes in the two layers are alternately arranged in the first direction, the projections of the first electrodes in the two layers in the first direction are tangential, a dielectric layer is arranged between the first electrodes in the two layers, and the first electrodes in the two layers have a second interval in the optical axis direction, and the second interval is larger than the first interval). The second electrodes located between the liquid crystal layer and one group and the first electrodes in this group are alternately arranged in a first direction, which is perpendicular to the optical axis, and the second electrodes partially overlap with the first electrodes adjacent thereto, and in this embodiment, the first direction is directed from the optical axis to the edge of the liquid crystal lens. Wherein the first electrode is configured to output a driving voltage, and the second electrode is used as a floating electrode (f l oat i ng).

step S791: a first liquid crystal alignment layer is formed on the first substrate and is rubbed along a side of the first common electrode layer where the first common electrode layer is located. Step S791 may be performed, for example, after step S470, and the first liquid crystal alignment layer may be formed by, for example, coating polyimide on the surface of the first electrode layer or the third electrode layer.

Step S792: and forming a second liquid crystal alignment layer on the second substrate, and rubbing and aligning along the side of the second common electrode layer where the second common electrode layer is located. Step S792 may be performed, for example, after step S480, and the second liquid crystal alignment layer may be formed by, for example, coating polyimide on the surface of the second electrode layer or the fourth electrode layer.

Finally, it should be noted that: the foregoing description is only illustrative of the present invention and is not intended to be limiting, and although the present invention has been described in detail with reference to the foregoing illustrative embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described above, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A liquid crystal lens having an optical axis, the liquid crystal lens comprising:

2. The liquid crystal lens according to claim 1, wherein the plurality of first electrodes in the first electrode layer are divided into a plurality of regions, and the plurality of first electrodes in the second electrode layer are divided into a plurality of regions, the regions having a preset width;

3. The liquid crystal lens of claim 2, wherein the width of the region is

4. The liquid crystal lens according to claim 2, wherein a third electrode layer is provided between the first electrode layer and the liquid crystal layer, and a first dielectric layer is provided between the first electrode layer and the third electrode layer; a fourth electrode layer is arranged between the second electrode layer and the liquid crystal layer, and a second dielectric layer is arranged between the second electrode layer and the fourth electrode layer; wherein the third electrode layer and the fourth electrode layer have the same structure;

5. The lc lens of claim 4, wherein the plurality of second electrodes are distributed between each of the enlarged groups and the lc layer.

6. The lc lens of claim 4, wherein the plurality of second electrodes are distributed between each of the groups and the lc layer.

7. The liquid crystal lens of claim 6, wherein, in the center group:

8. The lc lens of claim 4, wherein the plurality of second electrodes are distributed between each of the enlarged groups and the lc layer;

the first electrodes in the center group are arranged in two layers, and the first electrodes in the two layers are alternately arranged in the first direction, and a dielectric layer is arranged between the first electrodes in the two layers.

9. The liquid crystal lens according to claim 8, wherein the second electrode and the first electrode in the enlarged group have a first pitch in an optical axis direction; the first electrodes in the two layers have a second interval in the optical axis direction, and the second interval is larger than the first interval; the projections of the first electrodes of the two layers in the first direction are tangential.

10. The liquid crystal lens according to any one of claims 5 to 7, wherein a plurality of first electrodes in the first electrode layer are disposed at equal intervals from the optical axis to an edge of a first half region, and a plurality of first electrodes in the second electrode layer are disposed at equal intervals from the optical axis to an edge of a fourth half region.

11. The liquid crystal lens according to any one of claims 5 to 9, wherein the liquid crystal lens further comprises a circuit bus including a plurality of circuit branches that respectively supply different voltages, the number of the circuit branches being the same as the number of the first electrodes included in one region of the center group;

12. The liquid crystal lens of claim 11, wherein the circuit bus further comprises a maximum voltage branch and/or a minimum voltage branch;

13. The liquid crystal lens of claim 1, wherein the surface areas of the first electrodes in the same group are the same;

14. The liquid crystal lens of claim 1, wherein in the same group: the line width of the first electrode close to the optical axis is larger than that of the first electrode far away from the optical axis;

15. The liquid crystal lens according to claim 1, wherein a first liquid crystal alignment layer is provided on a side of the liquid crystal layer close to the first substrate, and the first liquid crystal alignment layer is rubbed and aligned along a side where the first common electrode layer is located;

16. A method of manufacturing a liquid crystal lens, comprising:

arranging a spacer on the first substrate or the second substrate;

17. The method of manufacturing of claim 16, further comprising:

18. The method of manufacturing of claim 17, wherein the plurality of second electrodes are distributed between each of the enlarged electrode resistances and the liquid crystal layer.

19. The method of manufacturing of claim 17, wherein the plurality of second electrodes are distributed between each of the groups and the liquid crystal layer.

20. The method of manufacturing of claim 17, wherein the plurality of second electrodes are distributed between each of the enlarged groups and a liquid crystal layer;

21. The manufacturing method according to claim 20, wherein the second electrode has a first pitch in an optical axis direction from the first electrode in the enlarged group; the first electrodes in the two layers have a second interval in the optical axis direction, and the second interval is larger than the first interval; the projections of the first electrodes of the two layers in the first direction are tangential.

22. The method of manufacturing of claim 16, further comprising: