Display device and method for manufacturing display device

Abstract

This application discloses a display device and a method for manufacturing the display device, belonging to the field of display technology. The display device includes: at least one pixel unit; the pixel unit includes a lower substrate, a liquid crystal unit, and an upper substrate stacked together; the upper substrate includes a common electrode layer, at least one dielectric layer, and a transparent substrate stacked along a direction away from the liquid crystal unit; the common electrode layer, dielectric layer, and transparent substrate are all functional layers; the refractive indices of two adjacent functional layers along the stacking direction in the upper substrate are different; incident light from the outside enters from one side of the upper substrate, passes through the upper substrate, and enters the liquid crystal unit to form display reflected light; the dielectric layer is configured such that when the display reflected light exits from the liquid crystal unit through the upper substrate to the outside, the interface reflected light formed between two adjacent functional layers along the stacking direction in the upper substrate undergoes destructive interference. This application improves the transmittance of reflected light by adding and configuring a dielectric layer between the common electrode layer and the transparent substrate.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display device and a method for manufacturing the display device. Background Technology

[0002] Electronic paper (E-Paper), also known as digital paper or paper-like display, is an electronic display device that provides a visual experience similar to paper. Based on its display principle, electronic paper can be categorized into electrophoretic electronic paper, cholesteric liquid crystal electronic paper, and toner electronic paper. Among these, cholesteric liquid crystal electronic paper relies on a twisted cholesteric liquid crystal layer to reflect light of a specific wavelength and, thanks to the bistable nature of cholesteric liquid crystals, can maintain its image even after power is off, thus making it widely used.

[0003] Conventional cholesteric liquid crystal electronic paper, such as Figure 1 As shown, it mainly includes an upper substrate 3, a lower substrate 1, and a liquid crystal layer 21 and a support structure 22 located between the two substrates; wherein the upper substrate 3 includes a common electrode layer 31 and a transparent substrate 33 stacked together. External incident light enters from one side of the upper substrate 3, enters the liquid crystal layer 21 through the upper substrate 3 and undergoes Bragg reflection to form the initial display reflected light; the initial display reflected light then passes through the common electrode layer 31 and the transparent substrate 33 of the upper substrate 3 in sequence to form the final display reflected light, which is emitted outward and enters the human eye.

[0004] Indium tin oxide (ITO) has good conductivity and transparency, so the common electrode layer 31 in the above conventional structure is generally made of ITO, while the transparent substrate 33 is generally made of silicon dioxide glass substrate. Figure 2 As shown, due to the refractive index difference between ITO and silicon dioxide, the initial display reflected light will be reflected when it passes through the interface between the common electrode layer 31 and the transparent substrate 33, forming interface reflected light. This results in a decrease in the intensity of the final display reflected light compared to the initial display reflected light, i.e., a decrease in transmittance, thereby affecting the display brightness of the display device.

[0005] like Figure 3 The transmission spectra of the conventional top substrate and the glass substrate shown are presented. The measured data show that, compared with a single glass substrate, the transmittance of the conventional top substrate composed of the ITO common electrode layer and the glass substrate decreases by 8% to 17%, and the decrease is greater in the blue band than in the red band. Summary of the Invention

[0006] The purpose of this application is to provide a display device and a method for manufacturing the display device, so as to improve the transmittance of reflected light and thereby improve the display brightness of the display device.

[0007] To achieve the above objectives, this application provides a display device, comprising: at least one pixel unit; the pixel unit comprising a lower substrate, a liquid crystal unit, and an upper substrate stacked together;

[0008] The upper substrate includes a common electrode layer, at least one dielectric layer, and a transparent substrate stacked along a direction away from the liquid crystal cell; the common electrode layer, the dielectric layer, and the transparent substrate are all functional layers; the refractive indices of two adjacent functional layers along the stacking direction in the upper substrate are different.

[0009] External incident light enters from one side of the upper substrate, passes through the upper substrate and enters the liquid crystal cell to form display reflected light; the dielectric layer is configured such that when the display reflected light exits from the liquid crystal cell through the upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate undergoes interference cancellation.

[0010] Optionally, the display device is a monochrome display device; the color of the reflected light generated by each of the liquid crystal cells is the same;

[0011] The upper substrate includes a common electrode layer, at least two dielectric layers, and a transparent substrate stacked in a direction away from the liquid crystal cell; the refractive index of each dielectric layer is alternately set at high and low along the stacking direction.

[0012] Optionally, the display device is a single-layer multi-color display device; the single-layer multi-color display device includes:

[0013] The lower substrate, the liquid crystal cell array, and the upper substrate are stacked together; the liquid crystal cell array includes at least two liquid crystal cells arranged in an array in a plane parallel to the lower substrate; the color of the display reflected light generated by each liquid crystal cell is different.

[0014] The upper substrate includes a common electrode layer, a dielectric layer array, and a transparent substrate stacked in a direction away from the liquid crystal cell; the dielectric layer array includes at least two dielectric layers arranged in an array in a plane parallel to the upper substrate; the dielectric layers and the liquid crystal cells correspond one-to-one; the liquid crystal cell, the lower substrate, and the upper substrate in the corresponding region constitute a pixel unit.

[0015] Optionally, the incident light from the outside enters from one side of the upper substrate, passes through the upper substrate, and enters the liquid crystal cell in the corresponding area to form the display reflected light;

[0016] The dielectric layer in the corresponding region is configured such that when the display reflected light formed by the corresponding liquid crystal cell is emitted from the liquid crystal cell through the upper substrate of the corresponding region to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate of the corresponding region undergoes interference cancellation.

[0017] Optionally, the display device is a multi-color stacked display device; the multi-color stacked display device includes:

[0018] At least two pixel units are stacked together; each pixel unit includes a lower substrate, a liquid crystal unit, and an upper substrate stacked together; the color of the display reflected light generated by each liquid crystal unit is different;

[0019] The incident light from the outside enters from the upper substrate side of the uppermost pixel unit, passes through the upper substrate of each pixel unit in sequence, and enters the corresponding liquid crystal unit to form display reflected light of different colors.

[0020] Optionally, the dielectric layer structure of each pixel unit is the same, and each dielectric layer is matched with the display reflected light of all colors; each dielectric layer is configured such that, for any color of display reflected light, when the display reflected light is emitted from the corresponding liquid crystal unit through the corresponding upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the corresponding upper substrate undergoes interference cancellation.

[0021] Optionally, the dielectric layer of each pixel unit is matched with the color type of the display reflected light passing through the dielectric layer; each dielectric layer is configured according to the color type of the display reflected light passing through the dielectric layer as follows:

[0022] When the display reflected light of the current pixel unit is emitted from the liquid crystal unit of the current pixel unit through the upper substrate of the current pixel unit to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate of the current pixel unit will interfere and cancel each other out.

[0023] Furthermore, when a lower pixel unit exists, for any lower pixel unit, when the display reflected light is emitted from the lower pixel unit through the upper substrate of the current pixel unit to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction within the upper substrate of the current pixel unit will undergo interference cancellation.

[0024] Optionally, the thickness of the dielectric layer is configured such that when the display reflected light is emitted from the liquid crystal cell through the upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate undergoes destructive interference.

[0025] Optionally, when the display device is a monochrome display device, the thickness of each of the dielectric layers is the same, which is 50nm~1000nm, including the values ​​at both ends;

[0026] Alternatively, when the display device is a single-layer multi-color display device, the thickness of each of the dielectric layers is different, ranging from 30nm to 200nm, including the values ​​at both ends;

[0027] Alternatively, when the display device is a multi-color stacked display device, the thickness of each of the dielectric layers is the same, which is 500nm~700nm, including the values ​​at both ends;

[0028] Alternatively, when the display device is a multi-color display device with multiple layers, the thickness of each of the medium layers is different, and each layer is matched with the color of the display reflected light passing through the medium layer.

[0029] Optionally, the refractive index of the dielectric layer is 2 to 2.4, including the values ​​at both ends;

[0030] And / or, the dielectric layer includes a silicon nitride layer, a magnesium fluoride layer, a niobium pentoxide layer, or a titanium dioxide layer.

[0031] To achieve the above objectives, this application also provides a method for manufacturing a display device, comprising:

[0032] The system provides at least one upper substrate and at least one lower substrate; the upper substrate includes a common electrode layer, at least one dielectric layer, and a transparent substrate stacked together; the common electrode layer, the dielectric layer, and the transparent substrate are all functional layers; the refractive indices of two adjacent functional layers along the stacking direction in the upper substrate are different;

[0033] With the common electrode layer facing the lower substrate, at least one liquid crystal cell is formed between the upper substrate and the lower substrate, such that the lower substrate, the liquid crystal cell, and the upper substrate are stacked to form a pixel unit, thereby obtaining a display device; the dielectric layer is configured during the fabrication process as follows:

[0034] When external incident light enters from one side of the upper substrate, and the display reflected light formed after passing through the upper substrate and entering the liquid crystal cell, exits from the liquid crystal cell through the upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate undergoes interference cancellation.

[0035] Optionally, when the display device is a single-layer multi-color display device and the thickness of each of the dielectric layers is different, providing at least one upper substrate includes:

[0036] A dielectric layer array is formed on the surface of the transparent substrate through multiple film deposition, exposure, and etching processes, or through a single film deposition, exposure, and etching process using a halftone mask; the dielectric layer array includes at least two dielectric layers arranged in an array in a plane parallel to the upper substrate; the dielectric layers correspond one-to-one with the liquid crystal cells;

[0037] The common electrode layer is formed on the entire surface of the transparent substrate having the dielectric layer to obtain the upper substrate.

[0038] Obviously, the display device provided in this application adds at least one dielectric layer between the common electrode layer and the transparent substrate, compared to a conventional substrate. The display reflected light of a specific wavelength generated by the liquid crystal cell, as it passes sequentially through the common electrode layer, the dielectric layer, and the transparent substrate, forms interface reflected light at the interfaces of adjacent functional layers. Optical interference occurs between these interface reflected lights. Based on the principle of thin-film interference, by configuring the dielectric layer to cause destructive interference between the interface reflected lights, the intensity of the interface reflected light can be reduced, thereby significantly improving the transmittance of the display reflected light and effectively increasing the display brightness of the display device. This application also provides a method for manufacturing the display device, which has the above-mentioned beneficial effects. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of a conventional cholesteric liquid crystal electronic paper;

[0041] Figure 2 This is a schematic diagram of the upper substrate structure in a conventional cholesteric liquid crystal electronic paper.

[0042] Figure 3 The transmission spectra of a conventional substrate and a glass substrate are shown.

[0043] Figure 4 This is a schematic diagram of the structure of a first display device provided in an embodiment of this application;

[0044] Figure 5 This is a schematic diagram of the structure of the upper substrate in the first type of display device provided in the embodiments of this application;

[0045] Figure 6 A reflection spectrum of a first type of liquid crystal cell provided in an embodiment of this application;

[0046] Figure 7 Transmission spectra of a first type of upper substrate and a conventional upper substrate provided in the embodiments of this application;

[0047] Figure 8 This is a schematic diagram of the structure of a second display device provided in an embodiment of this application;

[0048] Figure 9 This is a schematic diagram of the structure of a third display device provided in an embodiment of this application;

[0049] Figure 10 Transmission spectra of the third type of upper substrate provided in the embodiments of this application and a conventional upper substrate;

[0050] Figure 11 This is a schematic diagram of the structure of the fourth display device provided in the embodiments of this application;

[0051] Figure 12 This application provides a flowchart of a method for manufacturing a display device.

[0052] The annotations in the attached figures are explained as follows:

[0053] 01 - Pixel unit;

[0054] 1-Lower substrate; 12-Gate driving line; 13-Insulating layer; 14-Pixel electrode; 15-Ink layer;

[0055] 2-Liquid crystal cell; 21-Liquid crystal layer; 211-Liquid crystal molecule; 22-Support structure;

[0056] 3-Upper substrate; 31-Common electrode layer; 32-Dielectric layer; 33-Transparent substrate; 34-Black matrix. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0058] To make the technical solution of this application clearer and easier to understand, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0059] Please refer to Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the structure of a first display device provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of the upper substrate in a first display device provided in an embodiment of this application. The first display device provided in an embodiment of this application may include: at least one pixel unit 01; the pixel unit 01 includes a lower substrate 1, a liquid crystal unit 2, and an upper substrate 3 stacked together;

[0060] The upper substrate 3 includes a common electrode layer 31, at least one dielectric layer 32, and a transparent substrate 33 stacked along the direction away from the liquid crystal cell 2; the common electrode layer 31, the dielectric layer 32, and the transparent substrate 33 are all functional layers; the refractive indices of two adjacent functional layers along the stacking direction in the upper substrate 3 are different.

[0061] External incident light enters from one side of the upper substrate 3, passes through the upper substrate 3 and enters the liquid crystal cell 2 to form display reflected light; the dielectric layer 32 is configured such that when the display reflected light exits from the liquid crystal cell 2 through the upper substrate 3 to the outside, the interface reflected light formed between two adjacent functional layers along the stacking direction in the upper substrate 3 will interfere and cancel each other out.

[0062] In one possible implementation, the display device of this embodiment can be a monochrome display device; the color of the reflected light formed by each liquid crystal cell 2 is the same. Further, the monochrome display device can include a single-layer monochrome display device and a multi-layer monochrome display device; wherein, in a single-layer monochrome display device, all pixel cells 01 are located in the same plane; in a multi-layer monochrome display device, all pixel cells 01 are stacked. This embodiment does not limit the specific color of the reflected light; in one possible implementation, the color of the reflected light can be red, green, blue, or other colors.

[0063] In addition, the display device in this embodiment can be a single-layer multi-color display device or a multi-layer multi-color display device. For details, please refer to the following embodiments, which will not be repeated here.

[0064] This embodiment does not limit the specific type of the common electrode layer 31 in the upper substrate 3. In one possible implementation, the common electrode layer 31 can be an ITO common electrode layer; the refractive index of the ITO common electrode layer can be 1.8 to 2.0, including the values ​​at both ends; the thickness of the ITO common electrode layer can be 50 nm to 100 nm, including the values ​​at both ends.

[0065] This embodiment does not limit the specific type of the transparent substrate 33 in the upper substrate 3. In one possible implementation, the transparent substrate 33 can be a glass substrate, and the material of the glass substrate can be silicon dioxide; the refractive index of the glass substrate can be 1.5~1.55, including the values ​​at both ends.

[0066] This embodiment does not limit the specific number of dielectric layers 32 in the upper substrate 3. In one possible implementation, it may include one dielectric layer 32 or at least two dielectric layers 32. The refractive indices of each dielectric layer 32 may be different or partially the same. In one possible implementation, the upper substrate 3 may include a common electrode layer 31, at least two dielectric layers 32, and a transparent substrate 33 stacked along the direction away from the liquid crystal cell 2; the refractive indices of each dielectric layer 32 may be alternately set at high and low values ​​along the stacking direction. It should be noted that reflected light will be reflected at the interface between any two adjacent functional layers along the stacking direction within the upper substrate 3, and the resulting interface reflected light will each form an interference effect. By using stacked dielectric layers with alternating high and low refractive indices, an anti-reflection effect can be achieved for reflected light in multiple wavelength bands.

[0067] This embodiment does not limit the specific type of dielectric layer 32 in the upper substrate 3. In one possible implementation, the dielectric layer 32 may include a transparent dielectric layer with a low absorption coefficient, such as a silicon nitride layer, a magnesium fluoride layer, a niobium pentoxide layer, or a titanium dioxide layer.

[0068] In this embodiment, the refractive index of the dielectric layer 32 in the substrate 3 needs to satisfy the requirement that the refractive indices of adjacent functional layers are different. In one possible implementation, the refractive index of the dielectric layer 32 can be less than the refractive index of the transparent substrate 33; or greater than the refractive index of the common electrode layer 31; or between the refractive indices of the transparent substrate 33 and the common electrode layer 31. Further, the refractive index of the dielectric layer 32 can be 2 to 2.4, including the values ​​at both ends.

[0069] like Figure 5 As shown, taking a structure with a dielectric layer 32 added between the common electrode layer 31 and the transparent substrate 33 as an example, the refractive index of the dielectric layer 32 is different from that of the common electrode layer 31 and the transparent substrate 33. The initial display reflected light is reflected when it passes through the interface between the common electrode layer 31 and the dielectric layer 32, forming the first interface reflected light; then it is also reflected when it passes through the interface between the dielectric layer 32 and the transparent substrate 33, forming the second interface reflected light. When the optical path difference between the first interface reflected light and the second interface reflected light is an odd multiple of half a wave, interference cancellation occurs, weakening the interface reflected light and enhancing the transmitted display reflected light, thereby improving the transmittance.

[0070] It should be noted that, in order for the reflected light from each interface to undergo destructive interference, the dielectric layer 32 needs to be configured based on the principle of thin-film interference to satisfy the conditions for destructive thin-film interference:

[0071] ;

[0072] In the formula, n represents the refractive index of the dielectric layer 32; d represents the thickness of the dielectric layer 32; λ represents the wavelength of the reflected light, and the wavelength of the reflected light at the interface is the same as the wavelength of the reflected light; m represents the interference order, which is a non-negative integer.

[0073] In this embodiment, the refractive index of the dielectric layer 32 can be fixed (i.e., a dielectric layer 32 with a specific refractive index is selected) based on the range of the reflection spectrum of the liquid crystal cell 2 (i.e., the wavelength range of the display reflected light that the liquid crystal cell 2 can generate), and the phase difference of the reflected light at each interface can be matched by configuring the thickness of the dielectric layer 32; or the thickness of the dielectric layer 32 can be fixed, and the phase difference of the reflected light at each interface can be matched by configuring the refractive index of the dielectric layer 32 (i.e., a dielectric layer 32 with a different refractive index is selected), so that the reflected light at the interface with a specific wavelength can achieve interference cancellation.

[0074] In one possible implementation, the thickness of the dielectric layer 32 can be configured such that when the reflected light from the liquid crystal cell 2 is emitted to the outside via the upper substrate 3, the reflected light from the interface formed between two adjacent functional layers in the stacking direction within the upper substrate 3 undergoes interference cancellation.

[0075] Furthermore, the thickness of each dielectric layer 32 can be the same, ranging from 50nm to 1000nm, including the values ​​at both ends. It should be noted that different colors of display reflected light have different wavelengths, and the corresponding thickness of the dielectric layer 32 is also different. The specific thickness of the dielectric layer 32 can be determined according to the color of the display reflected light.

[0076] This embodiment does not limit the specific type of liquid crystal cell 2. In one possible implementation, the liquid crystal cell 2 may include a liquid crystal layer 21 and a support structure 22 surrounding the liquid crystal layer 21; the liquid crystal layer 21 may be a cholesteric liquid crystal layer.

[0077] This embodiment does not limit the specific type of the substrate 1. For details, please refer to the following embodiments, which will not be repeated here.

[0078] The technical effects of the first type of display device described above are illustrated below with specific examples. Please refer to them. Figure 6 and Figure 7 , Figure 6 A reflection spectrum of a first type of liquid crystal cell provided in an embodiment of this application; Figure 7 Transmission spectra of a first type of upper substrate and a conventional upper substrate provided in the embodiments of this application.

[0079] This embodiment takes three monochrome display devices—red, green, and blue—as examples and uses Macleod thin-film design software for simulation. The refractive index of the ITO common electrode layer in the three monochrome display devices is set to 1.936, the thickness of the ITO common electrode layer is set to 50 nm, and the dielectric layer is set to Nb2O5 (refractive index 2.3). The reflection spectrum of the liquid crystal cell and the transmission spectrum of the upper substrate in the three monochrome display devices are simulated when the dielectric layer thicknesses are 58 nm, 83 nm, and 107 nm, respectively.

[0080] like Figure 6 The reflection spectrum of the liquid crystal cell shown shows that the transmittance of the three monochrome display devices reaches its maximum value at wavelengths of 650nm, 550nm, and 450nm, respectively, which corresponds one-to-one with the main peaks of the red, green, and blue display reflected light wavelengths.

[0081] like Figure 7 The transmission spectrum of the upper substrate shown demonstrates that the transmittance of the three dielectric layers at the main wavelengths of the reflected light in red (650nm), green (550nm), and blue (450nm) at the corresponding wavelengths is improved to varying degrees compared to the transmittance of a conventional upper substrate (including a stacked ITO common electrode layer and a glass substrate). Therefore, when the main wavelength of the reflected light from the liquid crystal cell changes, it can be matched to the corresponding wavelength of the reflected light by adjusting the thickness of the dielectric layer.

[0082] Please refer to Figure 8 , Figure 8 This is a schematic diagram of the structure of a second display device provided in an embodiment of this application. Unlike the pixel unit configuration in the first display device embodiment described above, the display device in this embodiment is a single-layer multi-color display device; the single-layer multi-color display device includes:

[0083] The lower substrate 1, the liquid crystal cell array, and the upper substrate 3 are stacked together; the liquid crystal cell array includes at least two liquid crystal cells 2 arranged in an array in a plane parallel to the lower substrate 1; each liquid crystal cell 2 generates a different color of the display reflected light.

[0084] The upper substrate 3 includes a common electrode layer 31, a dielectric layer array, and a transparent substrate 33 stacked along the direction away from the liquid crystal cell 2; the dielectric layer array includes at least two dielectric layers 32 arranged in an array in a plane parallel to the upper substrate 3; the dielectric layers 32 correspond one-to-one with the liquid crystal cells 2; the liquid crystal cells 2 and the corresponding lower substrate 1 and upper substrate 3 constitute a pixel unit 01.

[0085] It should be noted that in this embodiment, different liquid crystal units 2 share the upper substrate 3 and the lower substrate 1; different liquid crystal units 2 use different types of liquid crystal layers 21, and different types of liquid crystal layers 21 can form display reflected light of different colors respectively.

[0086] This embodiment does not limit the specific color of the reflected light. In one possible implementation, the reflected light can be at least two colors selected from red, green, or blue. Figure 8 Taking the structure shown as an example, it can include three pixel units 01 located in the same plane. The three pixel units 01 can respectively form red display reflected light, green display reflected light and blue display reflected light.

[0087] In one possible implementation, external incident light enters from one side of the upper substrate 3, passes through the upper substrate 3 and enters the liquid crystal cell 2 in the corresponding area to form display reflected light;

[0088] The dielectric layer 32 in the corresponding region can be configured such that when the display reflected light formed by the corresponding liquid crystal cell 2 is emitted from the liquid crystal cell 2 through the upper substrate 3 in the corresponding region to the outside, the interface reflected light formed at the interface between two adjacent functional layers in the upper substrate 3 along the stacking direction in the corresponding region will interfere and cancel each other out.

[0089] Furthermore, the thickness of each dielectric layer 32 can be different, ranging from 30nm to 200nm, including the values ​​at both ends. It should be noted that in this embodiment, the thickness of the dielectric layer 32 corresponding to different liquid crystal cells 2 is different. By adjusting the thickness of the dielectric layer 32, the transmission spectrum of the upper substrate 3 can be matched one-to-one with the reflection spectrum of the liquid crystal cell 2, thereby improving the light transmittance.

[0090] It should be noted that the remaining contents have been described in detail in the embodiment of the first display device, and will not be repeated here.

[0091] Please refer to Figure 9 , Figure 9 This is a schematic diagram of the structure of a third display device provided in this application embodiment. Unlike the first display device embodiment described above, this embodiment provides another configuration of pixel units. In this embodiment, the display device is a multi-color stacked display device; the multi-color stacked display device includes:

[0092] At least two pixel units 01 are stacked; each pixel unit 01 includes a lower substrate 1, a liquid crystal unit 2 and an upper substrate 3 stacked; the color of the display reflected light formed by each liquid crystal unit 2 is different.

[0093] It should be noted that in this embodiment, different pixel units 01 have independent lower substrate 1, liquid crystal unit 2 and upper substrate 3; different liquid crystal units 2 use different types of liquid crystal layers 21, and different types of liquid crystal layers 21 can form display reflected light of different colors respectively.

[0094] This embodiment does not limit the specific color of the reflected light. In one possible implementation, the reflected light can be at least two colors selected from red, green, or blue. Figure 9 Taking the structure shown as an example, it can include three pixel units 01 stacked together, and the three pixel units 01 can respectively form red display reflected light, green display reflected light and blue display reflected light.

[0095] It should be noted that, since the pixel units 01 in this embodiment are arranged in a stacked manner, the display reflected light formed by the lower pixel unit (i.e. the pixel unit 01 located on the non-light-emitting side of the current pixel unit) needs to pass through all the pixel units 01 above it in sequence before entering the human eye. Therefore, when configuring the medium layer 32 of the current pixel unit, not only the reflection spectrum of the liquid crystal unit 2 in the current pixel unit should be considered, but also the reflection spectrum of the liquid crystal unit 2 in the lower pixel unit.

[0096] In one possible implementation, external incident light enters from the upper substrate 3 side of the uppermost pixel unit 01, passes through the upper substrate 3 of each pixel unit 01 in sequence, and enters the corresponding liquid crystal unit 2 to form display reflected light of different colors.

[0097] Each pixel unit 01 has the same dielectric layer 32 structure, and each dielectric layer 32 is matched with the display reflected light of all colors. Each dielectric layer 32 is configured such that, for any color of display reflected light, when the display reflected light is emitted from the corresponding liquid crystal unit 2 through the corresponding upper substrate 3 to the outside, the interface reflected light formed between two adjacent functional layers in the corresponding upper substrate 3 along the stacking direction will interfere and cancel each other out.

[0098] Furthermore, the thickness of each dielectric layer 32 can be the same, ranging from 500nm to 700nm, including the values ​​at both ends. It should be noted that the dielectric layer 32 used in this embodiment can enhance the transmittance of the display reflected light of all pixel units 01, so different liquid crystal units 2 can use dielectric layers 32 of the same thickness.

[0099] In another possible implementation, external incident light enters from the upper substrate 3 side of the uppermost pixel unit 01, passes through the upper substrate 3 of each pixel unit 01 in sequence, and enters the corresponding liquid crystal unit 2 to form display reflected light of different colors.

[0100] The dielectric layer 32 of each pixel unit 01 is matched with the color type of the display reflected light passing through the dielectric layer 32; each dielectric layer 32 is configured according to the color type of the display reflected light passing through the dielectric layer 32 as follows:

[0101] When the display reflected light of the current pixel unit is emitted from the liquid crystal unit 2 of the current pixel unit through the upper substrate 3 of the current pixel unit to the outside, the interface reflected light formed between two adjacent functional layers in the upper substrate 3 of the current pixel unit along the stacking direction will interfere and cancel each other out.

[0102] Furthermore, when a lower pixel unit exists, for any lower pixel unit, when the display reflected light is emitted from the lower pixel unit through the upper substrate 3 of the current pixel unit to the outside, the interface reflected light formed between two adjacent functional layers along the stacking direction in the upper substrate 3 of the current pixel unit will interfere and cancel each other out.

[0103] Furthermore, the thickness of each dielectric layer 32 can be different, each matching the color type of the display reflected light passing through the dielectric layer 32. It should be noted that the dielectric layer 32 used in this embodiment can only enhance the transmittance of the display reflected light of the current pixel unit and the display reflected light of the pixel unit below the current pixel unit. Therefore, different liquid crystal units 2 need to use dielectric layers 32 of different thicknesses.

[0104] It should be noted that the remaining contents have been described in detail in the embodiment of the first display device, and will not be repeated here.

[0105] The technical effects of the third type of display device described above are illustrated below with specific examples. Please refer to them. Figure 10 , Figure 10 Transmission spectra of the third type of upper substrate provided in the embodiments of this application and a conventional upper substrate.

[0106] This embodiment uses a multi-color display device composed of red, green, and blue pixel units as an example, and simulates it using Macleod thin-film design software: The refractive index of the ITO common electrode layer in the multi-color display device is set to 1.936, the thickness of the ITO common electrode layer is set to 50 nm, the dielectric layer is set to Nb2O5 (refractive index 2.3), and the thickness of the dielectric layer is set to 550 nm, simulating the transmission spectrum of the upper substrate in the multi-color display device. For example... Figure 10 The transmission spectrum of the upper substrate shown demonstrates that a dielectric layer of a single thickness can simultaneously enhance the transmittance of reflected light from red, green, and blue displays.

[0107] Please refer to Figure 11 , Figure 11This is a schematic diagram of the structure of a fourth display device provided in the embodiments of this application. Unlike the embodiments of the first display device described above, in this embodiment, the lower substrate 1 may include a transparent substrate 33. The transparent substrate 33 may be provided with a gate driving line 12, a signal line, at least one insulating layer 13, a pixel electrode 14, and a transistor switch for controlling a single pixel unit 01 on the side surface near the liquid crystal unit 2, and an ink layer 15 may be provided on the side surface away from the liquid crystal unit 2.

[0108] It should be noted that in this embodiment, the insulating layer 13 is disposed between any two adjacent conductive structures to achieve electrical isolation.

[0109] In one possible implementation, the upper substrate 3 may further include a black matrix 34. It should be noted that the black matrix 34 can be used to cover the metal traces on the lower substrate 1, and it can completely absorb light.

[0110] This embodiment does not limit the specific location of the black matrix 34. In one possible implementation, the black matrix 34 may be located between the common electrode layer 31 and the dielectric layer 32, or between the dielectric layer 32 and the transparent substrate 33.

[0111] In one possible implementation, taking the display of red and black dual colors as an example, the liquid crystal layer 21 in the liquid crystal cell 2 uses a cholesteric liquid crystal layer with a pitch of liquid crystal molecules 211 that reflects red wavelengths. The ink layer 15 is black. By applying different pulse voltages to the liquid crystal layer 21 through the common electrode layer 31 and the pixel electrode 14, two stable states can be achieved: a planar state (P-state) and a focal cone state (FC-state). When the cholesteric liquid crystal layer is in the FC-state, incident light from the outside entering the display device is absorbed by the bottom black ink layer 15, displaying black. When the cholesteric liquid crystal layer is in the P-state, the cholesteric liquid crystal layer reflects red wavelength light, and the remaining light passing through the cholesteric liquid crystal layer is also completely absorbed by the bottom black ink layer 15. By adjusting the pitch of the liquid crystal molecules 211 of the cholesteric liquid crystal layer used, different colors of light such as red, green, and blue can be reflected respectively.

[0112] The remaining contents have been described in detail in the embodiments of the first display device, and will not be repeated here.

[0113] Please refer to Figure 12 , Figure 12 A flowchart illustrating a method for manufacturing a display device according to an embodiment of this application is provided. This method may include:

[0114] S101: Provide at least one upper substrate and at least one lower substrate; the upper substrate includes a common electrode layer, at least one dielectric layer and a transparent substrate stacked together; the common electrode layer, dielectric layer and transparent substrate are all functional layers; the refractive indices of two adjacent functional layers along the stacking direction in the upper substrate are different.

[0115] This embodiment does not limit the specific manner in which the upper and lower substrates are provided; the method can be determined based on the specific types of the upper and lower substrates. In one possible implementation, when the display device is a single-layer multi-color display device and the thicknesses of each dielectric layer are different, at least one upper substrate is provided, which may include:

[0116] A dielectric layer array is formed on the surface of a transparent substrate through multiple film deposition, exposure, and etching processes, or through a single film deposition, exposure, and etching process using a halftone mask; the dielectric layer array includes at least two dielectric layers arranged in an array in a plane parallel to the upper substrate; the dielectric layers correspond one-to-one with the liquid crystal cells;

[0117] A common electrode layer is formed on the entire surface of a transparent substrate with a dielectric layer to obtain an upper substrate.

[0118] S102: With the common electrode layer facing the lower substrate, at least one liquid crystal cell is formed between the upper and lower substrates, and the lower substrate, liquid crystal cell, and upper substrate are stacked to form a pixel unit, thereby obtaining a display device; the dielectric layer is configured as follows during the fabrication process:

[0119] When external incident light enters from one side of the upper substrate, the reflected light formed after passing through the upper substrate and entering the liquid crystal cell is emitted from the liquid crystal cell through the upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate will interfere and cancel each other out.

[0120] Based on the above embodiments, this application is able to prepare the above-mentioned display device, and therefore has the same beneficial effects as described above.

[0121] This document uses specific examples to illustrate the principles and implementation methods of this application. The various embodiments are progressive, with each embodiment focusing on its differences from others. Similar or identical parts between embodiments can be referred to interchangeably. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of this application. For those skilled in the art, various improvements and modifications can be made to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

[0122] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. 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 process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

Claims

1. A display device, characterized in that, include: At least one pixel unit; the pixel unit includes a lower substrate, a liquid crystal unit, and an upper substrate stacked together. The upper substrate includes a common electrode layer, at least one dielectric layer, and a transparent substrate stacked along a direction away from the liquid crystal cell; the common electrode layer, the dielectric layer, and the transparent substrate are all functional layers; the refractive indices of two adjacent functional layers along the stacking direction in the upper substrate are different. External incident light enters from one side of the upper substrate, passes through the upper substrate and enters the liquid crystal cell to form display reflected light; the dielectric layer is configured such that when the display reflected light exits from the liquid crystal cell through the upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate undergoes interference cancellation.

2. The display device according to claim 1, wherein The display device is a monochrome display device; the color of the reflected light generated by each of the liquid crystal cells is the same. The upper substrate includes a common electrode layer, at least two dielectric layers, and a transparent substrate stacked in a direction away from the liquid crystal cell; the refractive index of each dielectric layer is alternately set at high and low along the stacking direction.

3. The display device according to claim 1, wherein The display device is a single-layer multi-color display device; the single-layer multi-color display device includes: The lower substrate, the liquid crystal cell array, and the upper substrate are stacked together; the liquid crystal cell array includes at least two liquid crystal cells arranged in an array in a plane parallel to the lower substrate; the color of the display reflected light generated by each liquid crystal cell is different. The upper substrate includes a common electrode layer, a dielectric layer array, and a transparent substrate stacked in a direction away from the liquid crystal cell; the dielectric layer array includes at least two dielectric layers arranged in an array in a plane parallel to the upper substrate; the dielectric layers and the liquid crystal cells correspond one-to-one; the liquid crystal cell, the lower substrate, and the upper substrate in the corresponding region constitute a pixel unit.

4. The display device according to claim 3, wherein The incident light from the outside enters from one side of the upper substrate, passes through the upper substrate and enters the liquid crystal cell in the corresponding area to form the display reflected light; The dielectric layer in the corresponding region is configured such that when the display reflected light formed by the corresponding liquid crystal cell is emitted from the liquid crystal cell through the upper substrate of the corresponding region to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate of the corresponding region undergoes interference cancellation.

5. The display device according to claim 1, wherein The display device is a multi-color stacked display device; the multi-color stacked display device includes: At least two pixel units are stacked together; each pixel unit includes a lower substrate, a liquid crystal unit, and an upper substrate stacked together; the color of the display reflected light generated by each liquid crystal unit is different.

6. The display device according to claim 5, wherein The incident light from the outside enters from the upper substrate side of the uppermost pixel unit, passes through the upper substrate of each pixel unit in sequence, and enters the corresponding liquid crystal unit to form display reflected light of different colors; The dielectric layer structures of each pixel unit are identical, and each dielectric layer is matched with the display reflected light of all colors; each dielectric layer is configured such that, for any color of display reflected light, when the display reflected light is emitted from the corresponding liquid crystal unit through the corresponding upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the corresponding upper substrate undergoes interference cancellation.

7. The display device according to claim 5, wherein The incident light from the outside enters from the upper substrate side of the uppermost pixel unit, passes through the upper substrate of each pixel unit in sequence, and enters the corresponding liquid crystal unit to form display reflected light of different colors; The dielectric layer of each pixel unit is matched with the color type of the display reflected light passing through the dielectric layer; each dielectric layer is configured according to the color type of the display reflected light passing through the dielectric layer as follows: When the display reflected light of the current pixel unit is emitted from the liquid crystal unit of the current pixel unit through the upper substrate of the current pixel unit to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate of the current pixel unit will interfere and cancel each other out. Furthermore, when a lower pixel unit exists, for any lower pixel unit, when the display reflected light is emitted from the lower pixel unit through the upper substrate of the current pixel unit to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction within the upper substrate of the current pixel unit will undergo interference cancellation.

8. The display device according to any one of claims 1 to 7, characterized by The thickness of the dielectric layer is configured such that when the display reflected light is emitted from the liquid crystal cell through the upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate undergoes interference cancellation.

9. A method for producing a display device, characterized by include: The system provides at least one upper substrate and at least one lower substrate; the upper substrate includes a common electrode layer, at least one dielectric layer, and a transparent substrate stacked together; the common electrode layer, the dielectric layer, and the transparent substrate are all functional layers; the refractive indices of two adjacent functional layers along the stacking direction in the upper substrate are different; With the common electrode layer facing the lower substrate, at least one liquid crystal cell is formed between the upper substrate and the lower substrate, such that the lower substrate, the liquid crystal cell, and the upper substrate are stacked to form a pixel unit, thereby obtaining a display device; the dielectric layer is configured during the fabrication process as follows: When external incident light enters from one side of the upper substrate, and the display reflected light formed after passing through the upper substrate and entering the liquid crystal cell, exits from the liquid crystal cell through the upper substrate to the outside, the interface reflected light formed at the interface between two adjacent functional layers along the stacking direction in the upper substrate undergoes interference cancellation.

10. The method of producing a display device according to claim 9, wherein When the display device is a single-layer multi-color display device, and the thickness of each of the dielectric layers is different, providing at least one upper substrate includes: A dielectric layer array is formed on the surface of the transparent substrate through multiple film deposition, exposure, and etching processes, or through a single film deposition, exposure, and etching process using a halftone mask; the dielectric layer array includes at least two dielectric layers arranged in an array in a plane parallel to the upper substrate; the dielectric layers correspond one-to-one with the liquid crystal cells; The common electrode layer is formed on the entire surface of the transparent substrate having the dielectric layer to obtain the upper substrate.

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