Liquid crystal fresnel lens and electronic product

Abstract

The application belongs to the technical field of liquid crystal lens and relates to a liquid crystal Fresnel lens and an electronic product. The application provides a liquid crystal Fresnel lens, which comprises a first substrate, a first electrode layer, a first orientation layer, a liquid crystal layer, a second orientation layer, a second electrode layer and a second substrate arranged in sequence; the first electrode layer is a surface electrode; the second electrode layer comprises a plurality of electrode units arranged in sequence from the center to the edge of the second electrode layer; the electrode unit comprises a first potential distribution line and a second potential distribution line; the first potential distribution line is provided with a first position and a second position, and the second potential distribution line is provided with a third position and a fourth position; and the application can significantly improve the optical effect of the liquid crystal Fresnel lens.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal lens technology, and more particularly to a liquid crystal Fresnel lens and electronic products. Background Technology

[0002] A Fresnel lens is a lens designed based on the principle that the curvature of an optical surface determines its imaging characteristics. It maintains the surface curvature during design but reduces its thickness during manufacturing. This design allows the lens to still converge light, focusing incident light onto a focal point. Since a spherical lens can be considered as several discontinuous components in actual manufacturing and application, removing excess portions does not affect light deflection as long as the original surface curvature is maintained during manufacturing. The function of these discontinuous components is achieved by a central circle and a series of concentric rings on the Fresnel lens; these central circles and concentric rings are known as the Fresnel rings of the Fresnel lens.

[0003] Based on the fundamental principles of Fresnel lenses, electrically controllable focusing liquid crystal Fresnel lenses have been designed. A liquid crystal Fresnel lens consists of multiple Fresnel rings. Each Fresnel ring of a liquid crystal Fresnel lens, driven by a set of driving voltages, can achieve an optical effect equivalent to that of a regular Fresnel ring. Through the synergistic effect of all the Fresnel rings in the liquid crystal Fresnel lens, an optical effect equivalent to that of a regular Fresnel lens can be achieved. Because the driving voltage used to drive each Fresnel ring of the liquid crystal Fresnel lens is relatively small, focusing of larger lenses can be achieved using a relatively small driving voltage.

[0004] Current liquid crystal Fresnel lenses employ an electrode pair consisting of two concentric circular electrodes to control the electric field distribution within a Fresnel annular region. By using multiple electrode pairs to control the electric field distribution of their respective Fresnel annular regions, a field distribution capable of simulating the optical effect of a complete Fresnel lens is created. While the circular electrode pair structure can simulate the optical effect of a Fresnel lens to some extent, this electrode structure has poor precision in controlling the potential distribution within the Fresnel annular region, failing to achieve a precisely parabolic potential distribution. Therefore, the resulting Fresnel liquid crystal lens exhibits less than ideal optical performance. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a liquid crystal Fresnel lens and an electronic product to solve the technical problem of poor optical performance of existing liquid crystal Fresnel lenses.

[0006] The technical solution adopted in this invention is:

[0007] In a first aspect, the present invention provides a liquid crystal Fresnel lens, comprising a first substrate, a first electrode layer, a first alignment layer, a liquid crystal layer, a second alignment layer, a second electrode layer, and a second substrate, which are sequentially stacked.

[0008] The first electrode layer is a surface electrode;

[0009] The second electrode layer includes a plurality of electrode units arranged sequentially from the center to the edge of the second electrode layer;

[0010] The electrode unit includes a first potential distribution line, a second potential distribution line, and a plurality of concentric arc electrode lines disposed between the first potential distribution line and the second potential distribution line. At least one end of the concentric arc electrode line is connected to the first potential distribution line or the second potential distribution line.

[0011] The first potential distribution line is provided with a first position for receiving a first driving voltage and a second position for receiving a second driving voltage, and the second potential distribution line is provided with a third position for receiving a first driving voltage and a fourth position for receiving a second driving voltage.

[0012] A portion of the concentric arc electrode lines connected to the first potential distribution line are located on one side of the circumferential direction of the first potential distribution line, while another portion are located on the other side of the circumferential direction of the first potential distribution line. The position where the first potential distribution line connects to the concentric arc electrode lines is the first reference position. The resistance values ​​between each first reference position and the first position on the same side of the circumferential direction of the first potential distribution line and the distance between the corresponding first reference position and the first position along the radial direction of the second electrode layer exhibit a parabolic distribution.

[0013] A portion of the concentric arc electrode lines connected to the second potential distribution line are located on one side of the circumferential direction of the second potential distribution line, while another portion are located on the other side of the circumferential direction of the second potential distribution line. The position where the second potential distribution line connects to the concentric arc electrode lines is the second reference position. The resistance values ​​between each second reference position and the third position on the same side of the circumferential direction of the second potential distribution line and the distance between the corresponding second reference position and the third position along the radial direction of the second electrode layer exhibit a parabolic distribution.

[0014] Preferably, the outer contour of the area shared by all electrode units is circular.

[0015] Preferably, the outer contour of the area shared by all electrode units is non-circular.

[0016] Preferably, the outer contour of the area shared by all electrode units is elliptical.

[0017] Preferably, the first driving voltage loading line and the second driving voltage loading line are connected at the first position and the third position to the first driving voltage loading line, and at the second position and the fourth position to the second driving voltage loading line. The first driving voltage loading line includes a first main line and several first branch lines formed by branches of the first main line and second branch lines formed by branches of the first branch lines. The first position or the third position is connected to the first main line, the first branch line, or the second branch line.

[0018] The second driving voltage loading line includes a second main line, several third branches formed by branches of the second main line, and a fourth branch formed by branches of the third branches. The second position or the fourth position is connected to the main line, the first branch, or the second branch.

[0019] Preferably, the first potential distribution line or the second potential distribution line includes several extension segments and several connecting segments, with each end of the connecting segment connected to two adjacent extension segments; the connecting segments are arranged along the radial direction of the second electrode layer; the several extension segments are arc-shaped; the connecting segments are staggered along the circumferential direction of the second electrode layer, and the spacing between adjacent extension segments is less than or equal to 100 μm.

[0020] Preferably, the first potential distribution line has the same width in the portion between the first position and the second position, and the length of each first reference position to the first position of the first potential distribution line is parabolic to the distance from each first reference position to the first position along the radial direction of the second electrode layer.

[0021] The portion of the second potential distribution line between the third and fourth positions has the same width, and the length of the second potential distribution line between each second reference position and the third position is parabolic to the distance between each second reference position and the third position along the radial direction of the second electrode layer.

[0022] Preferably, a high-resistivity film or a high-dielectric-constant layer is disposed between the second electrode layer and the second alignment layer, or

[0023] A high-resistivity film or a high-dielectric-constant layer is disposed between the second electrode layer and the second substrate.

[0024] Preferably, the surface electrode and each of the electrode units, driven by the first driving voltage and the second driving voltage, deflect the liquid crystal in the liquid crystal layer to form a liquid crystal Fresnel lens.

[0025] In a second aspect, the present invention also provides an electronic product, including a control circuit and the liquid crystal Fresnel lens described in the first aspect, wherein the control circuit is electrically connected to the liquid crystal Fresnel lens.

[0026] Beneficial Effects: The liquid crystal Fresnel lens and electronic product of the present invention utilize the electric field distribution generated by electrode units arranged sequentially from the center to the edge on the second electrode layer to achieve the optical function of each annular region of the Fresnel lens. For each electrode unit, a gradient potential distribution is formed along the radial direction of the lens using a first potential distribution line and a second potential distribution line. The potentials of the first and second potential distribution lines are guided to the respective regions controlled by the electrode unit by concentric arc lines. Then, by setting the connection position between the concentric arc electrode lines and the two potential distribution lines, each electrode unit generates a precisely parabolic electric field distribution. In this way, the annular regions of the liquid crystal layer controlled by the electrode units can achieve an optical effect that is closest to the ideal Fresnel annular region. Since the liquid crystal Fresnel lens of the present invention only requires controlling two driving voltages to precisely control the potential distribution of the liquid crystal Fresnel lens, it not only has good optical effect, but its control method is also very simple, and the product cost is lower. Furthermore, by providing a gradient potential distribution through two separately set potential distribution lines, the potential distribution can still be maintained even after the concentric arc electrode lines are partially interrupted, thus enabling the fabrication of liquid crystal Fresnel lenses with arbitrary contour shapes. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, and these are all within the protection scope of the present invention.

[0028] Figure 1 This is a cross-sectional view of the liquid crystal Fresnel lens of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of the second electrode layer in the liquid crystal Fresnel lens of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of each electrode unit in the second electrode layer of the present invention after disassembly;

[0031] Figure 4 This is a schematic diagram of the structure of the electrode unit with a complete ring band according to the present invention;

[0032] Figure 5 This is a schematic diagram of the structure of the electrode unit with the ring belt broken in the middle according to the present invention;

[0033] Figure 6 This is a schematic diagram of the structure of the second electrode unit in the liquid crystal Fresnel lens of the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of the first potential distribution line of the present invention;

[0035] Figure 8 This is a schematic diagram of the structure of the second potential distribution line of the present invention;

[0036] Figure 9 This is a schematic diagram of the structure of the liquid crystal Fresnel lens with a driving voltage loading line according to the present invention;

[0037] Figure 10 This is a diagram showing the arrangement of the driving voltage loading lines of the present invention;

[0038] Figure 11 This is a schematic diagram of the structure of the first driving voltage loading line of the present invention;

[0039] Figure 12 This is a schematic diagram of the structure of the second driving voltage loading line of the present invention;

[0040] Figure 13 This is an exploded structural diagram of the second electrode layer with a driving voltage loading line according to the present invention;

[0041] Parts and their numbers in the diagram:

[0042] First substrate 10, first electrode layer 20, first alignment layer 30, liquid crystal layer 40, second alignment layer 50, second electrode layer 60, second substrate 70, electrode unit 61, first potential distribution line 611, first position 6111, second position 6112, second potential distribution line 612, third position 6121, fourth position 6122, concentric arc electrode line 613, extension segment 614, connecting segment 615, first reference position 616, second reference position 617, first side 601, second side 602, third side 603, fourth side 604, first driving voltage loading line 62, first main line 621, first branch line 622, second branch line 623, second driving voltage loading line 63, second main line 631, third branch line 632, fourth branch line 633. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, the element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Where there is no conflict, embodiments of the present invention and the various features thereof can be combined with each other, all of which are within the scope of protection of the present invention.

[0044] Example 1

[0045] like Figure 1 The present embodiment provides a liquid crystal Fresnel lens. The liquid crystal Fresnel lens of this embodiment adopts a layered structure, mainly including a first substrate 10, a first electrode layer 20, a first alignment layer 30, a liquid crystal layer 40, a second alignment layer 50, a second electrode layer 60, and a second substrate 70.

[0046] The first electrode layer 20 adopts a planar electrode structure, so that when a voltage is applied to the surface electrode of the first electrode layer 20, the first electrode layer 20 can form an equipotential surface.

[0047] like Figure 2 and Figure 3As shown, the second electrode layer 60 includes a plurality of electrode units 61, which are arranged sequentially from the center to the edge of the second electrode layer 60. Since the concentric rings of a Fresnel lens are arranged in concentric rings from the inside out, the liquid crystal Fresnel lens of this embodiment utilizes the regular deflection of liquid crystal molecules in the liquid crystal layer 40 of each ring region under the action of an electric field to achieve the function of each concentric ring of the Fresnel lens. Thus, the liquid crystal lens achieves an optical effect equivalent to that of a Fresnel lens. The function of the area controlled by the electric field generated by one electrode unit 61 is the same as the optical function of one concentric ring of a conventional Fresnel lens.

[0048] In order to achieve the overall optical effect of a Fresnel lens by coordinating the areas controlled by the electric fields generated by each electrode unit 61, the arrangement of the electrode units 61 in this embodiment is consistent with the central circle or concentric ring arrangement of a normal Fresnel lens, and can be arranged in a ring-by-ring manner from the inside out.

[0049] In this embodiment, the liquid crystal Fresnel lens controls the electric field distribution of the liquid crystal layer 40 through each electrode unit 61 in the second electrode layer 60. Each electrode unit 61 controls the electric field distribution of the annular region where the electrode unit 61 is located in the liquid crystal layer 40, causing the liquid crystal molecules in the controlled annular region of the liquid crystal layer 40 to deflect according to a certain pattern. The phase delay generated after light passes through the controlled annular region of the liquid crystal layer 40 is the same as the phase delay generated after light passes through the corresponding concentric annular region of a conventional Fresnel lens. Thus, the optical function of the annular region of the liquid crystal layer 40 controlled by each electrode unit 61 in the liquid crystal Fresnel lens is the same as the optical function of each concentric annular region in a conventional Fresnel lens.

[0050] Since each electrode unit 61 controls the annular region in the liquid crystal layer 40, which can realize the optical function of the corresponding annular region in the Fresnel lens, and the arrangement of the electrode units 61 is the same as the arrangement of the concentric annular regions of the Fresnel liquid crystal lens, under the combined action of all electrode units 61, all annular regions in the middle layer of the liquid crystal form an overall structure of a liquid crystal Fresnel lens, which has the same overall optical effect as a regular liquid crystal Fresnel lens.

[0051] With the aforementioned structure, if the electric field distribution of each ring in the liquid crystal Fresnel lens can be precisely controlled, the optical effect of each Fresnel ring can be significantly improved, thereby giving the liquid crystal Fresnel lens a better overall optical effect.

[0052] The current technique of using electrode pairs to control the electric field distribution in the Fresnel annular region, although requiring only two driving voltages to control the electric field distribution, has a large error compared to the ideal parabolic distribution.

[0053] like Figure 4 , Figure 5 and Figure 6 As shown, in order to accurately control the electric field distribution in the Fresnel ring region, the electrode unit 61 in this embodiment includes a first potential distribution line 611, a second potential distribution line 612, and a plurality of concentric arc electrode lines 613 disposed between the first potential distribution line 611 and the second potential distribution line 612. At least one end of the concentric arc electrode line 613 is connected to the first potential distribution line 611 or the second potential distribution line 612.

[0054] The first potential distribution line 611 and the second potential distribution line 612 are made of conductive lines with a certain resistance, or they can be thin lines with a certain resistance and conductivity plated on the surface of the second substrate 70. As an optional but advantageous implementation, the potential gradient distribution lines in this embodiment can also be made of transparent conductive materials, so that the potential distribution lines will not affect the light transmission effect of the liquid crystal Fresnel lens. The transparent conductive materials include, but are not limited to, ITO electrode materials, FTO electrode materials, AZO electrode materials, IGZO electrode materials, IZO electrode materials, etc. The concentric arc electrode lines 613 refer to arc lines with the same center. In order to improve the light transmission effect of the liquid crystal lens, the concentric arc electrode lines 613 in this embodiment can also be made of transparent materials.

[0055] like Figure 7 As shown, the first potential distribution line 611 is provided with a first position 6111 for receiving the first driving voltage and a second position 6112 for receiving the second driving voltage, as follows: Figure 8 As shown, the second potential distribution line 612 is provided with a third position 6121 for receiving the first driving voltage and a fourth position 6122 for receiving the second driving voltage.

[0056] When a first driving voltage is applied at the first position 6111 of the first potential distribution line 611, and a second driving voltage is applied at the second position 6112 of the first potential distribution line 612, a gradient potential can be generated on the first potential distribution line 611. This results in different potentials at different positions on the first potential distribution line 611. For example, the potential gradually decreases from the first position 6111 to the second position 6112, or gradually increases from the first position 6111 to the second position 6112.

[0057] Similarly, when a first driving voltage is applied at the third position 6121 of the second potential distribution line 612, and a second driving voltage is applied at the fourth position 6122 of the second potential distribution line 612, a gradient potential can be generated on the second potential distribution line 612. This results in different potentials at different positions on the second potential distribution line 612. For example, the potential gradually decreases from the third position 6121 to the fourth position 6122 of the second potential distribution line 612, or gradually increases from the third position 6121 to the fourth position 6122 of the second potential line.

[0058] The connection of at least one end of the concentric arc electrode line 613 to the first potential distribution line 611 or the second potential distribution line 612 includes the following cases:

[0059] One end of the concentric arc electrode line 613 is connected to the first potential distribution line 611, while the other end is suspended.

[0060] One end of the concentric arc electrode line 613 is connected to the second potential distribution line 612, while the other end is suspended.

[0061] One end of the concentric arc electrode line 613 is connected to the first potential distribution line 611, and the other end is connected to the second potential distribution line 612.

[0062] Regardless of the aforementioned connection method used for the concentric arc electrode lines 613, the potential at each position on the concentric arc electrode lines 613 can be made equal, and equal to the potential at the connection point of the first potential distribution line 611 or the second potential distribution line 612 connected to it. Therefore, by setting the connection positions of each concentric arc equipotential line to the first potential distribution line 611 or the second potential distribution line 612, the potential on each concentric arc electrode line 613 can be controlled, and then the potential in the circumferential direction of the second electrode layer 60 can be controlled through the concentric arc equipotential lines. Figure 6 By extending along the Y direction (in the Fresnel annular region), the potential distribution at the locations traversed by the concentric arc electrode line 613 in the Fresnel annular region where the electrode unit 61 is located can be precisely controlled.

[0063] Furthermore, since this embodiment employs two potential distribution lines, a first potential distribution line 611 and a second potential distribution line 612, in the same electrode unit 61, the concentric arc electrode line 613 can be connected to either the first potential distribution line 611 or the second potential distribution line 612.

[0064] When the outer contour of the second electrode layer 60 of the liquid crystal Fresnel lens is not circular, some Fresnel rings on the periphery of the second electrode layer 60 are incomplete rings. In this case, a portion of the concentric arc electrode lines 613 will be interrupted at the edge of the second electrode layer 60. Concentric arcs at the same diameter position will be separated into at least two segments, making it difficult for the potential of the same concentric arc electrode line 613 to extend to various positions of the same diameter of the lens. In this embodiment, by using two potential distribution lines, different portions of the concentric arc electrode lines 613 at the same diameter position can be connected to the first potential distribution line 611 and the second potential distribution line 612 respectively. This allows the concentric arc electrode lines 613 at various portions of the same diameter position to cover various regions of the same diameter position in the second electrode layer 60, and to control the electric field distribution of various regions at the same diameter position with the same potential. This extends the application range of the liquid crystal Fresnel lens in this embodiment to lenses with various outer contour shapes.

[0065] In this embodiment, a portion of the concentric arc electrode lines 613 connected to the first potential distribution line 611 are located on one side of the first potential distribution line 611 in the circumferential direction, and another portion of the concentric arc electrode lines 613 are located on the other side of the first potential distribution line 611 in the circumferential direction.

[0066] In this embodiment, concentric arc electrode lines 613 are provided on both sides of the first potential distribution line 611 so that the concentric arc electrode lines 613 can cover each region of the Fresnel ring.

[0067] The position where the first potential distribution line 611 connects to the concentric arc electrode line 613 is designated as the first reference position 616. Since multiple concentric arc lines connect to the first potential distribution line 611, there are multiple first reference positions 616; that is, each concentric arc electrode line 613 connected to the first potential distribution line 611 corresponds to a first reference position 616. Because the concentric arc electrode lines 613 are distributed on both sides of the first potential distribution line 611, some of the concentric arc electrode lines 613 connect to the first potential distribution line 611 on one side of the circumferential direction of the potential distribution line, and the corresponding first reference positions 616 are also on one side of the circumferential direction of the potential distribution line. Conversely, some of the concentric arc electrode lines 613 connect to the first potential distribution line 611 on the other side of the circumferential direction of the first potential distribution line 611, and the corresponding first reference positions 616 are also on one side of the circumferential direction of the first potential distribution line 611.

[0068] In this embodiment, the resistance values ​​between each first reference position 616 and the first position 6111 on the same side of the first potential distribution line 611 in the circumferential direction are parabolicly distributed with respect to the distance between the corresponding first reference position 616 and the first position 6111 in the radial direction of the second electrode layer 60.

[0069] like Figure 6 and Figure 7 As shown, since the first potential distribution line 611 has two opposite sides in the circumferential direction, for ease of description, they are referred to as the first side 601 and the second side 602 respectively in this document. The parabolic distribution of the resistance values ​​between each first reference position 616 and the first position 6111 on the same side of the first potential distribution line 611 in the circumferential direction and the corresponding distances between the first reference positions 616 and the first positions 6111 in the radial direction of the second electrode layer 60 means that the resistance values ​​between each first reference position 616 and the first position 6111 on the first side 601 and the corresponding distances between the first reference positions 616 and the first positions 6111 in the radial direction of the second electrode layer 60 are parabolic. The resistance values ​​between each first reference position 616 and the first position 6111 on the second side 602 and the corresponding distances between the first reference positions 616 and the first positions 6111 in the radial direction of the second electrode layer 60 are also parabolic.

[0070] The resistance values ​​between each first reference position 616 and the first position 6111 are related to the resistance values ​​along the radial direction of the second electrode layer 60. Figure 6 The parabolic distribution of the distance from the first reference position 616 to the first position 6111 in the x-direction of the potential distribution line means that a rectangular coordinate system is established with the resistance value between the first reference position 616 and the first position 6111 in the radial direction of the second electrode layer 60 as the coordinate axes. In this rectangular coordinate system, the curve representing the relationship between the resistance value between each first reference position 616 and the first position 6111 of the potential distribution wire and the distance between the first reference position 616 and the first position 6111 in the radial direction of the second electrode layer 60 is a parabola.

[0071] When the electrode unit 61 is subjected to a first driving voltage and a second driving voltage at the first position 6111 and the second position 6112 respectively, the potential at a certain position on the potential distribution line depends on the resistance value between that position and the first position 6111. Therefore, this embodiment precisely controls the electric field distribution of the Fresnel annular region corresponding to the electrode unit 61 by setting the connection positions of each concentric arc electrode line 613 to the potential distribution line and the distance between each concentric arc electrode line 613 and the first position 6111 in the radial direction. With the aforementioned structure, this embodiment allows for precise control of the potential on each concentric arc electrode line 613 and the radial position of each concentric arc electrode line 613. Therefore, the potential distribution of the Fresnel annular region corresponding to the electrode unit 61 can be precisely controlled using a simple driving voltage control method.

[0072] like Figure 6 and Figure 8 As shown, similarly in this embodiment, a portion of the concentric arc electrode lines 613 connected to the second potential distribution line 612 are located on one side of the circumferential direction of the second potential distribution line 612, and another portion are located on the other side of the circumferential direction of the second potential distribution line 612. The position where the second potential distribution line 612 is connected to the concentric arc electrode lines 613 is the second reference position 617. The resistance values ​​between each second reference position 617 and the third position 6121 located on the same side of the circumferential direction of the second potential distribution line 612 and the distance between the corresponding second reference position 617 and the third position 6121 along the radial direction of the second electrode layer 60 are parabolically distributed.

[0073] In this embodiment, concentric arc electrode lines 613 are provided on both sides of the second potential distribution line 612 so that the concentric arc electrode lines 613 can cover all regions of the Fresnel ring. Since multiple concentric arc electrode lines 613 are connected to the second potential distribution line 612, there are also multiple second reference positions 617, that is, each concentric arc electrode line 613 connected to the second potential distribution line 612 corresponds to a second reference position 617. Since the concentric arc electrode lines 613 are distributed on both sides of the second potential distribution line 612, some of the concentric arc electrode lines 613 are connected to the second potential distribution line 612 on one side of the circumferential direction of the potential distribution line, and the second reference positions 617 corresponding to these concentric arc electrode lines 613 are also on one side of the circumferential direction of the potential distribution line. The connection point between another part of the concentric arc electrode lines 613 and the second potential distribution line 612 is on the other side of the circumferential direction of the second potential distribution line 612. The second reference position 617 corresponding to these concentric arc electrode lines 613 is also on one side of the circumferential direction of the second potential distribution line 612.

[0074] In this embodiment, the resistance values ​​between each second reference position 617 and the third position 6121 located on the same side of the second potential distribution line 612 in the circumferential direction are parabolically distributed with respect to the distance between the corresponding second reference position 617 and the third position 6121 in the radial direction of the second electrode layer 60.

[0075] like Figure 6 and Figure 8 As shown, since the second potential distribution line 612 has two opposite sides in the circumferential direction, for ease of description, they are referred to as the third side 604 and the fourth side 604 in this document. The parabolic distribution of the resistance values ​​between each second reference position 617 and the third position 6121 on the same side of the second potential distribution line 612 in the circumferential direction with respect to the distance between the corresponding second reference position 617 and the second position 6112 in the radial direction of the second electrode layer 60 means that: the resistance values ​​between each second reference position 617 and the third position 6121 on the third side 603 with respect to the distance between the corresponding second reference position 617 and the third position 6121 in the radial direction of the second electrode layer 60 are parabolic, and the resistance values ​​between each second reference position 617 and the third position 6121 on the fourth side 604 with respect to the distance between the corresponding second reference position 617 and the third position 6121 in the radial direction of the second electrode layer 60 are also parabolic.

[0076] The parabolic distribution of the resistance values ​​between each second reference position 617 and the third position 6121 and the corresponding distances between the second reference positions 617 and the third position 6121 along the radial direction of the second electrode layer 60 means that a rectangular coordinate system is established with the resistance values ​​between the second reference positions 617 and the third position 6121 of the potential distribution line and the corresponding distances between the first reference positions 616 and the third position 6121 along the radial direction of the second electrode layer 60 as coordinate axes. In this rectangular coordinate system, the curve representing the relationship between the resistance values ​​between each second reference position 617 and the third position 6121 of the potential distribution wire and the corresponding distances between the second reference positions 617 and the third position 6121 along the radial direction of the second electrode layer 60 is a parabola.

[0077] When the electrode unit 61 is subjected to the first driving voltage and the second driving voltage at the third position 6121 and the fourth position 6122 respectively, the potential at a certain position on the second potential distribution line 612 depends on the resistance value between that position and the third position 6121. Therefore, this embodiment precisely controls the electric field distribution of the Fresnel ring region corresponding to the electrode unit 61 by setting the connection position of each concentric arc electrode line 613 to the potential gradient distribution line and the distance between each concentric arc electrode line 613 and the third position 6121 in the radial direction. With the aforementioned structure, this embodiment enables precise control of the potential on each concentric arc electrode line 613 and the radial position of each concentric arc electrode line 613. Therefore, the potential distribution of the Fresnel ring region corresponding to the electrode unit 61 can be precisely controlled using a simple driving voltage control method.

[0078] Since the resistance values ​​between each first reference position 616 and the first position 6111 on the same side of the circumferential direction of the first potential gradient distribution line are parabolically distributed with respect to the distances between each first reference position 616 and the first position 6111 along the radial direction of the second electrode layer 60, and the resistance values ​​between each second reference position 617 and the third position 6121 on the same side of the circumferential direction of the second potential distribution line 612 are parabolically distributed with respect to the distances between the corresponding second reference positions 617 and the third position 6121 along the radial direction of the second electrode layer 60, the potential distribution in the annular region of the liquid crystal layer 40 controlled by each electrode unit 61 is also parabolically distributed. This results in the phase delay of light after passing through the annular region of the liquid crystal layer 40 after the liquid crystal molecules in the liquid crystal layer 40 are deflected under the action of the electric field, which is the same as the modulation effect of the ideal Fresnel annular region on light.

[0079] Using the solution in this embodiment, liquid crystal Fresnel lenses of any shape can be manufactured. Examples include circular liquid crystal lenses, elliptical liquid crystal lenses, rectangular liquid crystal lenses, and liquid crystal lenses of other shapes.

[0080] When the manufactured liquid crystal lens is circular, the outer contour of the area shared by all electrode units is circular. In this case, the area occupied by each electrode unit 61 is a complete circle or annulus.

[0081] When the fabricated liquid crystal lens is non-circular, the outer contour of the area shared by all electrode units is circular. The aforementioned non-circular refers to shapes other than circular. When the fabricated liquid crystal lens is elliptical, the outer contour of the area shared by all electrode units is elliptical. In this case, the area occupied by a portion of the electrode units 61 is an incomplete annulus, and the concentric arc electrode lines 613 cannot extend continuously. However, in this embodiment, by separately setting the first potential distribution line 611 and the second potential distribution line 612, the concentric arc electrode lines 613 of the same diameter maintain the same or similar potential. The aforementioned outer contour of the area shared by all electrode units refers to the outer contour of the entire area when the area shared by all electrode units in the second electrode layer is considered as a whole.

[0082] like Figure 9 and Figure 10 As shown, the second electrode layer 60 further includes a first driving voltage loading line 62 and a second driving voltage loading line 63. The first position 6111 and the third position 6121 are connected to the first driving voltage loading line 62. The first driving voltage of the first potential distribution line 611 and the second potential distribution line 612 is provided by the first driving voltage loading line 62. The second position 6112 and the fourth position 6122 are connected to the second driving voltage loading line 63, and the second driving voltage of the first potential distribution line 611 and the second potential distribution line 612 is provided by the second driving voltage loading line 63.

[0083] like Figure 11 As shown, the first driving voltage loading line 62 includes a first main line 621 and several first branch lines 622 formed by branches of the first main line 621 and second branch lines 623 formed by branches of the first branch lines 622. The first position 6111 is connected to the first main line 621, the first branch line 622, or the second branch line 623.

[0084] like Figure 12 As shown, the second driving voltage loading line 63 includes a second main line 631 and several third branch lines 632 formed by branches of the second main line 631 and a fourth branch line 633 formed by branches of the third branch lines 632. The second position 6112 is connected to the main line or the first branch line 622 or the second branch line 623.

[0085] like Figure 13 The aforementioned structure allows external voltage to be introduced through the first main line 621 and then through the first branch line 622 and the second branch line 623 to the first position 6111 or the third position 6121 of each electrode unit 61, so as to apply a first driving voltage to each electrode unit 61.

[0086] like Figure 13As shown, the aforementioned structure allows external voltage to be introduced through the second main line 631 and then through the third branch line 632 and the fourth branch line 633 to the second position 6112 or the fourth position 6122 of each electrode unit 61, so as to apply the first driving voltage to each electrode unit 61.

[0087] As an optional but advantageous implementation, in this embodiment, the width of the portion of the first potential gradient distribution line located between the first position 6111 and the second position 6112 is the same, and the length of each first reference position 616 to the first position 6111 of the first potential distribution line 611 is parabolic to the distance from each first reference position 616 to the first position 6111 along the radial direction of the second electrode layer 60.

[0088] The portion of the second potential gradient distribution line between the third position 6121 and the fourth position 6122 has the same width, and the length of the second potential distribution line 612 between each second reference position 617 and the third position 6121 is parabolic to the distance between each second reference position 617 and the third position 6121 along the radial direction of the second electrode layer 60.

[0089] When the width of the portion of the first potential distribution line 611 located between the first position 6111 and the second position 6112 is the same, the resistance value between each first reference position 616 and the first position 6111 on the first potential distribution line 611 is proportional to the length of the potential distribution wire between each first reference position 616 and the first position 6111.

[0090] Similarly, when the width of the portion of the second potential distribution line 612 located between the third position 6121 and the fourth position 6122 is the same, the resistance value between each second reference position 617 and the third position 6121 on the second potential distribution line 612 is proportional to the length of the potential distribution wire between each second reference position 617 and the third position 6121.

[0091] This embodiment can control the potential on each concentric arc by controlling the length of the first potential distribution line 611 between the first reference position 616 and the first position 6111 on the first potential distribution line and the length of the second potential distribution line 612 between the second reference position 617 and the second position 6112 on the second potential distribution line. This further simplifies the control of the electric field distribution in the ring region of the liquid crystal Fresnel lens, which is more conducive to obtaining a precise parabolic electric field distribution.

[0092] The first potential distribution line 611 or the second potential distribution line 612 includes several extension segments 614 and several connecting segments 615. The two opposite ends of each connecting segment 615 are connected to two adjacent extension segments 614. The connecting segments 615 are arranged along the radial direction of the second electrode layer 60. The several extension segments 614 are arc-shaped. The connecting segments 615 are staggered along the circumferential direction of the second electrode layer 60, so that the second potential distribution line 612 or the first potential distribution line 611 can bend back and forth, thereby increasing the length of the potential distribution conductor per unit distance in the radial direction. This improves the accuracy of potential control.

[0093] Since the spacing between adjacent extension segments 614 is less than or equal to 100 μm, the spacing between adjacent concentric arc electrode lines 613 in electrode unit 61 is also less than or equal to 100 μm. This embodiment achieves high-precision potential distribution by setting the spacing between extension segments 614 to within 100 μm, effectively eliminating potential abrupt changes between adjacent concentric arc electrode lines 613. This allows for an ideal potential distribution in the corresponding Fresnel ring region without using a high-impedance film, and successfully eliminates the influence of poor stability of high-impedance films or high-dielectric-constant materials on the stability of the liquid crystal lens effect.

[0094] This embodiment can also incorporate a high-impedance film or a high-dielectric-constant layer in the liquid crystal Fresnel lens. The aforementioned high-impedance film or high-dielectric-constant layer can be disposed between the second electrode layer 60 and the second alignment layer 50, or between the second electrode layer 60 and the second substrate 70. By employing a high-impedance film or a high-dielectric-constant layer in the liquid crystal Fresnel lens, the potential between adjacent concentric arc lines can be smoothed out, thereby further improving the performance of the liquid crystal Fresnel lens.

[0095] Example 2

[0096] The method for driving the liquid crystal Fresnel lens in this embodiment is described below. Assuming the first driving voltage is V1 and the second driving voltage is V2, the driving method includes the following steps:

[0097] S1: Obtain the linear operating range of the liquid crystal Fresnel lens;

[0098] The linear operating range of a liquid crystal refers to the voltage range in which the phase delay of the liquid crystal is linearly related to the driving voltage.

[0099] S2: Obtain the minimum voltage Vmin and maximum voltage Vmax within the linear working range of the liquid crystal based on the linear working range of the liquid crystal;

[0100] S3: Adjust the voltage difference between V1 and V2 according to the minimum voltage Vmin and the maximum voltage Vmax to adjust the optical power of the liquid crystal Fresnel lens, where Vmin≤V1≤Vmax and Vmin≤V2≤Vmax.

[0101] This step adjusts the optical power of the liquid crystal Fresnel lens by adjusting the difference between V1 and V2. Specifically, V1 can be kept constant while adjusting V2; V1 can be kept constant while adjusting V2; or both V1 and V2 can be changed simultaneously. When keeping V1 constant and adjusting V2, V1 can be set to Vmin or Vmax while adjusting V2; similarly, when keeping V2 constant and adjusting V1, V2 can be set to Vmin or Vmax while adjusting V1. As can be seen from the aforementioned method, the liquid crystal Fresnel lens in this embodiment only requires controlling two driving voltages to achieve simple and precise optical power adjustment.

[0102] Example 3

[0103] This embodiment provides an electronic product, which includes a control circuit and the liquid crystal Fresnel lens described in Embodiment 1. The control circuit is electrically connected to the liquid crystal Fresnel lens. The electronic product includes, but is not limited to, imaging devices, display devices, mobile phones, AR devices, VR devices, glasses-free 3D products, wearable devices, etc.

[0104] The above description is merely a specific embodiment of the present invention. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A liquid crystal Fresnel lens, characterized in that, It includes a first substrate, a first electrode layer, a first alignment layer, a liquid crystal layer, a second alignment layer, a second electrode layer, and a second substrate, which are stacked sequentially. The first electrode layer is a surface electrode; The second electrode layer includes a plurality of electrode units arranged sequentially from the center to the edge of the second electrode layer; The electrode unit includes a first potential distribution line, a second potential distribution line, and a plurality of concentric arc electrode lines disposed between the first potential distribution line and the second potential distribution line. At least one end of the concentric arc electrode line is connected to the first potential distribution line or the second potential distribution line. The first potential distribution line is provided with a first position for receiving a first driving voltage and a second position for receiving a second driving voltage, and the second potential distribution line is provided with a third position for receiving a first driving voltage and a fourth position for receiving a second driving voltage. A portion of the concentric arc electrode lines connected to the first potential distribution line are located on one side of the circumferential direction of the first potential distribution line, while another portion are located on the other side of the circumferential direction of the first potential distribution line. The position where the first potential distribution line connects to the concentric arc electrode lines is the first reference position. The resistance values ​​between each first reference position and the first position on the same side of the circumferential direction of the first potential distribution line and the distance between the corresponding first reference position and the first position along the radial direction of the second electrode layer exhibit a parabolic distribution. A portion of the concentric arc electrode lines connected to the second potential distribution line are located on one side of the circumferential direction of the second potential distribution line, while another portion are located on the other side of the circumferential direction of the second potential distribution line. The position where the second potential distribution line connects to the concentric arc electrode lines is the second reference position. The resistance values ​​between each second reference position and the third position on the same side of the circumferential direction of the second potential distribution line and the distance between the corresponding second reference position and the third position along the radial direction of the second electrode layer exhibit a parabolic distribution.

2. The liquid crystal Fresnel lens according to claim 1, characterized in that, The outer contour of the area shared by all electrode units is circular.

3. The liquid crystal Fresnel lens according to claim 1, characterized in that, The outer contour of the area shared by all the electrode units is non-circular.

4. The liquid crystal Fresnel lens according to claim 3, characterized in that, The outer contour of the area shared by all the electrode units is elliptical.

5. The liquid crystal Fresnel lens according to claim 1, characterized in that, The second electrode layer further includes a first driving voltage loading line and a second driving voltage loading line. The first position and the third position are connected to the first driving voltage loading line, and the second position and the fourth position are connected to the second driving voltage loading line. The first driving voltage loading line includes a first main line and several first branch lines formed by branches of the first main line and second branch lines formed by branches of the first branch lines. The first position or the third position is connected to the first main line, the first branch line, or the second branch line. The second driving voltage loading line includes a second main line, several third branches formed by branches of the second main line, and a fourth branch formed by branches of the third branches. The second position or the fourth position is connected to the main line, the first branch, or the second branch.

6. The liquid crystal Fresnel lens according to claim 1, characterized in that, The first potential distribution line or the second potential distribution line includes several extension segments and several connecting segments. The two opposite ends of the connecting segments are respectively connected to two adjacent extension segments. The connecting segments are arranged along the radial direction of the second electrode layer. The several extension segments are arc-shaped. The connecting segments are staggered along the circumferential direction of the second electrode layer, and the distance between adjacent extension segments is less than or equal to 100 μm.

7. The liquid crystal Fresnel lens according to claim 1, characterized in that, The first potential distribution line has the same width in the portion between the first position and the second position, and the length of each first reference position to the first position of the first potential distribution line is parabolic to the distance from each first reference position to the first position along the radial direction of the second electrode layer. The portion of the second potential distribution line between the third and fourth positions has the same width, and the length of the second potential distribution line between each second reference position and the third position is parabolic to the distance between each second reference position and the third position along the radial direction of the second electrode layer.

8. The liquid crystal Fresnel lens according to any one of claims 1 to 7, characterized in that, A high-resistivity film or a high-dielectric-constant layer is disposed between the second electrode layer and the second alignment layer, or A high-resistivity film or a high-dielectric-constant layer is disposed between the second electrode layer and the second substrate.

9. The liquid crystal Fresnel lens according to any one of claims 1 to 7, characterized in that, The surface electrode and each of the electrode units, driven by the first driving voltage and the second driving voltage, deflect the liquid crystal in the liquid crystal layer to form a liquid crystal Fresnel lens.

10. An electronic product, characterized in that, It includes a control circuit and a liquid crystal Fresnel lens according to any one of claims 1 to 9, wherein the control circuit is electrically connected to the liquid crystal Fresnel lens.

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