Liquid crystal lens array and glasses using same

Abstract

A liquid crystal lens array according to the present disclosure comprises: a liquid crystal layer (LC) formed between a first substrate (P1) and a second substrate (P2); pattern electrode layers (VC, VO) disposed between the first substrate and the liquid crystal layer, and formed by arranging a plurality of electrodes in a predetermined pattern; a ground electrode layer (VG) disposed between the second substrate and the liquid crystal layer; and a control unit that controls a voltage applied to the pattern electrode layers. Each liquid crystal lens is formed by each electrode of the pattern electrode layers, and a liquid crystal lens array is formed by an aggregate of the liquid crystal lenses. The control unit controls the voltage so as to set the lens power of each liquid crystal lens within a range from -5 diopters to +5 diopters.

Description

Liquid crystal lens array and eyeglasses using the same

[0001] The present disclosure relates to a liquid crystal lens array and eyeglasses using the same.

[0002] As described in Patent Literature 1, a liquid crystal lens array has been developed that utilizes the property of liquid crystals, that is, the refractive index changes depending on voltage. Specifically, Patent Literature 1 describes a lighting control device that does not have any moving parts, in which the focal length of the liquid crystal lens is changed by variably adjusting the voltage of electrodes sandwiching a liquid crystal layer. As an example, Patent Literature 1 describes that the liquid crystal lens array can be used as a three-dimensional display device that takes horizontal parallax into consideration in information processing terminals such as smartphones and tablet terminals.

[0003] JP 2014-112157 A

[0004] However, the above-mentioned Patent Document 1 only describes the use of the liquid crystal lens array as a 3D display device, and does not describe any other applications, which poses a problem that the liquid crystal lens array cannot be further utilized.

[0005] Therefore, an object of the present disclosure is to solve the above-mentioned problem of being unable to further utilize the liquid crystal lens array.

[0006] A liquid crystal lens array according to one embodiment of the present disclosure comprises: a first substrate and a second substrate; a liquid crystal layer formed between the first substrate and the second substrate; a patterned electrode layer disposed between the first substrate and the liquid crystal layer and formed by arranging a plurality of electrodes in a predetermined pattern; a ground electrode layer disposed between the second substrate and the liquid crystal layer; and a control unit that controls a voltage applied to the patterned electrode layer, wherein each liquid crystal lens is formed by each of the electrodes in the patterned electrode layer, and a liquid crystal lens array is formed by an assembly of the plurality of liquid crystal lenses, and the control unit controls the voltage to set the lens power of each of the liquid crystal lenses in the range of -5 diopters to +5 diopters.

[0007] In addition, in the liquid crystal lens array, the electrodes of the patterned electrode layer are formed so that the diameter of each liquid crystal lens is 1 mm or less.

[0008] In addition, in the liquid crystal lens array, the electrodes of the patterned electrode layer are configured to have a circular first electrode and a circular second electrode that is larger than the first electrode and has a hole formed therein so that the first electrode can be placed inside without contacting it.

[0009] In addition, in the liquid crystal lens array, the outer shape of the second electrode of the patterned electrode layer is approximately hexagonal, and the electrodes of the patterned electrode layer made up of the first electrode and the second electrode are arranged in a honeycomb pattern.

[0010] Furthermore, glasses according to one embodiment of the present disclosure are configured to include a liquid crystal lens array as a lens.

[0011] With the above-described configuration, the present disclosure can further utilize the liquid crystal lens array.

[0012] Fig. 1 is a diagram showing an example of the configuration of a liquid crystal lens array according to the present disclosure. Fig. 2 is a diagram showing an example of the configuration of a part of the liquid crystal lens array disclosed in Fig. 1. Fig. 3 is a diagram showing an example of the configuration of a part of the liquid crystal lens array disclosed in Fig. 1.

[0013] First Embodiment The present disclosure will be described with reference to the drawings. Fig. 1 shows a schematic plan view of a liquid crystal lens array, Fig. 2 shows an enlarged view and a cross-sectional view of a portion of the liquid crystal lens array, and Fig. 3 shows the dimensions of the liquid crystal lens array.

[0014] As shown in Fig. 1, the liquid crystal lens array of this embodiment includes patterned electrode layers VC and VO formed by arranging a plurality of electrodes in a predetermined pattern. Each electrode of the patterned electrode layers VC and VO forms a liquid crystal lens, and a collection of the plurality of liquid crystal lenses forms the liquid crystal lens array. The liquid crystal lens array of this embodiment can be used, for example, as a lens for eyeglasses. However, the liquid crystal lens array is not limited to being used as a lens for eyeglasses, and may also be used for other purposes.

[0015] Specifically, as shown in the A-A cross-sectional view of Figure 2, the liquid crystal lens array includes a liquid crystal layer LC formed between a first substrate P1 and a second substrate P2, patterned electrode layers VC and VO arranged between the first substrate P1 and the liquid crystal layer LC and formed with a plurality of electrodes arranged in a predetermined pattern, a ground electrode layer VG arranged between the second substrate P2 and the liquid crystal layer LC, and a control unit 10 that controls the voltage applied to the patterned electrode layers VC and VO. Furthermore, an insulating layer L and a high-resistance layer HR are arranged between the patterned electrode layers VC and LO and the liquid crystal layer LC. Each of the substrates, electrode layers, and other components are made of transparent materials.

[0016] The patterned electrode layers VC and VO include a first electrode VC formed with a plurality of circular electrodes and a second electrode VO formed with a plurality of annular electrodes positioned around each of the first electrodes VC. Specifically, as shown in Figures 1 and 2, the first electrode VC is formed with rows of individual circular electrodes connected by a wiring pattern VC', and multiple rows of such circular electrodes are arranged. For example, each circular electrode has a diameter W1 of 300 μm, and the width W4 of the wiring pattern VC' connecting the electrodes is 40 μm. The spacing between each row is W7 of 346 μm.

[0017] As shown in FIG. 2 , the second electrodes VO are formed in an annular shape with an approximately hexagonal outer shape and an internal hole. The internal hole of the second electrode VO is larger than the outer diameter of each circular electrode, the first electrode VC, and its internal diameter is W2 = 360 μm. The first electrode VC is placed in the internal hole of the second electrode VO without contacting it, thereby forming a 30 μm space between the first electrode VC and the second electrode VO. The minimum size of the outer shape of one second electrode VO is W3 = 400 μm, and the minimum width of the annular portion of the second electrode VO is W5 = 20 μm. A portion of the annular portion of one second electrode VO is removed to allow for the placement of the wiring pattern VC' of the first electrode VC, and the width of this removed portion is W6 = 60 μm. In this embodiment, the second electrode VO is described as having an outer shape that is approximately hexagonal, but in actuality, the electrodes are connected at their outer edges, and multiple holes are formed in which the corresponding first electrodes VC are placed.

[0018] By configuring the patterned electrode layers VC and VO as described above, one circular first electrode VC and one approximately hexagonal second electrode VO form a ground electrode VG and one liquid crystal lens. Specifically, application of a voltage by the control unit 10 changes the orientation of liquid crystal molecules in the liquid crystal layer LC between the one circular first electrode VC, the one approximately hexagonal second electrode VO, and the ground electrode VG, thereby forming one liquid crystal lens. In this embodiment, the diameter of one liquid crystal lens corresponds to the outer shape of the second electrode VO and is approximately 400 μm. In particular, it is desirable that each liquid crystal lens constituting the liquid crystal lens array of the present disclosure has a diameter of 1 mm or less.

[0019] In the liquid crystal lens array of this embodiment, the liquid crystal lenses are arranged in a honeycomb pattern, as shown in FIG. 2 . However, the arrangement of the liquid crystal lenses is not necessarily limited to a honeycomb pattern, and they may be arranged in a lattice pattern or in any other arrangement. Furthermore, the outer shape of the first electrode VC is not limited to a circular shape and may be any shape, and the outer shape of the second electrode VO is not limited to a substantially hexagonal shape and may be any shape. Furthermore, the above-mentioned dimensions of the first electrode VC and second electrode VO constituting the liquid crystal lens are merely examples, and any dimensions may be used.

[0020] The control unit 10 controls the focal length of each liquid crystal lens by variably adjusting the voltage applied to the pattern electrodes VC and VO. For example, the control unit 10 controls the voltage so that the lens power of each liquid crystal lens is set in the range of −5 diopters to +5 diopters. For example, when the diameter of each liquid crystal lens is 0.8 mm, the control unit 10 controls the lens power to ±5 diopters.

[0021] Here, we will explain the case where a liquid crystal lens array, which is an assembly of the above-mentioned liquid crystal lenses, is used as a lens for glasses. For example, if the distance between the eye and the glasses is about 2 cm and the distance to the object to be viewed is about 10 cm, the focus will be at 5 times the distance. Therefore, by controlling the lens power of each liquid crystal lens to achieve the above-mentioned lens power, the liquid crystal lens array can be used as a lens for glasses. In this case, although a liquid crystal lens component is located about 2 cm from the eye, the component is not noticeable to the viewer because the focus is at a position about 10 cm.

[0022] As mentioned above, if the lens power of each liquid crystal lens exceeds the range of ±5 diopters, an image will form on each liquid crystal lens, resulting in a compound eye lens. For this reason, it is desirable to control the voltage so that the lens power of each liquid crystal lens falls within the ±5 diopter range, where compound eye images are not formed.

[0023] When constructing a liquid crystal lens array as described above, since the liquid crystal lenses have a diameter of 1 mm or less, it is easy to increase the lens power and manufacture the liquid crystal lenses with uniform characteristics. Furthermore, since the lens power required for each individual liquid crystal lens in the liquid crystal lens array can be as small as ±5 diopters, the liquid crystal lens array can easily be made larger in diameter, enabling a stable supply of lenses. Furthermore, since the lens system of each liquid crystal lens is small, the liquid crystal layer can be formed thin. As described above, the liquid crystal lens array of this embodiment can be easily used as a lens for eyeglasses.

[0024] Furthermore, by using the above-described liquid crystal lens array as a lens for glasses, the effect of improving eyesight due to the pinhole effect can be further enhanced, which also makes it possible to effectively use the liquid crystal lens array as a lens for glasses.

[0025] Although the present disclosure has been described above with reference to the above-described embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each of the above-described embodiments can be combined with other embodiments as appropriate.

[0026] The present invention claims the benefit of priority based on patent application No. 2023-107058 filed in Japan on June 29, 2023, and all of the contents disclosed in the patent application are included in this specification.

[0027] 10 Control unit P1 First substrate P2 Second substrate LC Liquid crystal layer VC First electrode (pattern electrode layer) VO Second electrode (pattern electrode layer) VG Ground electrode

Claims

1. A liquid crystal lens array comprising: a first substrate and a second substrate; a liquid crystal layer formed between the first substrate and the second substrate; a patterned electrode layer disposed between the first substrate and the liquid crystal layer and formed by arranging a plurality of electrodes in a predetermined pattern; a ground electrode layer disposed between the second substrate and the liquid crystal layer; and a control unit for controlling a voltage applied to the patterned electrode layer, wherein each liquid crystal lens is formed by each of the electrodes in the patterned electrode layer, and a liquid crystal lens array is formed by an assembly of the plurality of liquid crystal lenses, and the control unit controls the voltage to set the lens power of each of the liquid crystal lenses in the range of -5 diopters to +5 diopters.

2. A liquid crystal lens array according to claim 1, wherein each of the electrodes of the pattern electrode layer is formed so that the diameter of each of the liquid crystal lenses is 1 mm or less.

3. A liquid crystal lens array as described in claim 1, wherein the electrodes of the patterned electrode layer are configured to have a circular first electrode and a circular second electrode larger than the first electrode and having a hole formed therein through which the first electrode is placed without contacting it.

4. A liquid crystal lens array as described in claim 3, wherein the outer shape of the second electrode of the patterned electrode layer is approximately hexagonal, and each of the electrodes of the patterned electrode layer consisting of the first electrode and the second electrode is arranged in a honeycomb pattern.

5. Eyeglasses equipped with the liquid crystal lens array according to claim 1 as a lens.

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