CN113272726A

CN113272726A - Display panel, display device and display panel manufacturing method

Info

Publication number: CN113272726A
Application number: CN201980002085.8A
Authority: CN
Inventors: 王龙; 杨登科; 秦广奎; 申润浩; 贾南方; 孙拓; 王志良
Original assignee: BOE Technology Group Co Ltd; Kent State University
Current assignee: BOE Technology Group Co Ltd; Kent State University
Priority date: 2019-10-24
Filing date: 2019-10-24
Publication date: 2021-08-17
Anticipated expiration: 2039-10-24
Also published as: CN113272726B; WO2021077356A1

Abstract

A display panel, a display device and a display panel manufacturing method, the display panel comprises an upper substrate (1), a lower substrate (2), and a liquid crystal layer (3) positioned between the upper substrate (1) and the lower substrate (2), the liquid crystal layer (3) comprises liquid crystal and high molecular polymer, wherein: the liquid crystal layer (3) has a plurality of pixel regions, and at least one of the pixel regions includes a primary scattering region (31) and a secondary scattering region (32); the first high molecular polymer located in the main scattering region (31) has a first molecular degree of polymerization, and the second high molecular polymer located in the auxiliary scattering region (32) has a second molecular degree of polymerization, which is smaller than the first molecular degree of polymerization, so that the contrast of display can be improved.

Description

Display panel, display device and display panel manufacturing method

Technical Field

The present disclosure relates to the field of display technologies, and in particular, to a display panel, a display device, and a method for manufacturing the display panel.

Background

With the development of display technology, transparent display devices such as transparent refrigerators, transparent show windows, transparent traffic signs, transparent watches, transparent vehicle-mounted display devices and the like gradually come into the lives of people, and the application prospect is very wide.

Disclosure of Invention

According to an aspect of the embodiments of the present disclosure, there is provided a display panel including an upper substrate, a lower substrate, and a liquid crystal layer between the upper substrate and the lower substrate, the liquid crystal layer including liquid crystal and a high molecular polymer, wherein: the liquid crystal layer has a plurality of pixel regions, and at least one pixel region of the plurality of pixel regions includes a main scattering region and an auxiliary scattering region; the first high molecular polymer positioned in the main scattering area has a first molecular polymerization degree, the second high molecular polymer positioned in the auxiliary scattering area has a second molecular polymerization degree, and the second molecular polymerization degree is smaller than the first molecular polymerization degree.

In a possible embodiment, a ratio of an area of an orthogonal projection of the main scattering area on the lower substrate to an area of an orthogonal projection of each of the at least one pixel region on the lower substrate is 50% or more.

In a possible implementation manner, the orthographic projection of the auxiliary scattering area on the lower substrate is a grid, and the meshes of the grid are rectangular; the size range of any side length of the meshes is 5 um-100 um, and the size range of the interval between any two adjacent meshes is 5 um-100 um.

In a possible embodiment, the auxiliary scattering region comprises a plurality of sub-auxiliary scattering regions, and orthographic projections of the plurality of sub-auxiliary scattering regions on the lower substrate are parallel to each other; wherein, in the arrangement direction of the sub-auxiliary scattering regions, the size range of any sub-auxiliary scattering region is 5 um-100 um, and the size range of the interval between any two adjacent sub-auxiliary scattering regions is 5 um-100 um.

In a possible embodiment, the display panel further includes an upper absorption layer on the upper substrate, and an orthogonal projection of the upper absorption layer on the lower substrate coincides with an orthogonal projection of the secondary scattering region on the lower substrate; and/or a lower absorption layer positioned on the lower substrate, wherein the orthographic projection of the lower absorption layer on the lower substrate is superposed with the orthographic projection of the auxiliary scattering region on the lower substrate.

In a possible embodiment, the display panel further includes an upper barrier layer on a surface of the upper substrate facing away from the liquid crystal layer, the upper barrier layer completely covering the surface of the upper substrate facing away from the liquid crystal layer; and/or the lower barrier layer is positioned on the surface of the lower substrate, which is opposite to the liquid crystal layer, and completely covers the surface of the lower substrate, which is opposite to the liquid crystal layer.

According to another aspect of the embodiments of the present disclosure, a display device is provided, which includes the display panel in any one of the above embodiments.

In a possible embodiment, the display device further comprises a plurality of monochromatic light sources configured to time-share the backlight of different wavelengths to the display panel.

According to still another aspect of the embodiments of the present disclosure, there is provided a display panel manufacturing method including: forming a liquid crystal box, wherein the liquid crystal box comprises an upper substrate, a lower substrate and a liquid crystal layer positioned between the upper substrate and the lower substrate, the liquid crystal layer comprises liquid crystal and polymerizable materials, and the liquid crystal layer is provided with a plurality of pixel regions; based on the blocking structure, carrying out polymerization treatment on the polymerizable material in at least one pixel region of the plurality of pixel regions, so that a region shielded by the pattern of the blocking structure in the at least one pixel region forms a secondary scattering region, and a region not shielded by the pattern of the blocking structure forms a primary scattering region; the first high molecular polymer formed by polymerizing the polymerizable material in the main scattering region has a first molecular polymerization degree, the second high molecular polymer formed by polymerizing the polymerizable material in the auxiliary scattering region has a second molecular polymerization degree, and the second molecular polymerization degree is smaller than the first molecular polymerization degree.

In a possible embodiment, the blocking structure is a mask covering the upper substrate and/or the lower substrate, and an orthogonal projection of a pattern of the mask on the lower substrate coincides with an orthogonal projection of the secondary scattering region on the lower substrate.

In a possible embodiment, the blocking structure is an upper absorption layer on the upper substrate, and an orthographic projection of the upper absorption layer on the lower substrate coincides with an orthographic projection of the secondary scattering region on the lower substrate, and/or a lower absorption layer on the lower substrate, and an orthographic projection of the lower absorption layer on the lower substrate coincides with an orthographic projection of the secondary scattering region on the lower substrate.

In a possible embodiment, the pattern of the barrier structures is a grid, and the meshes of the grid are rectangular; wherein, the size range of any side length of the meshes is 5 um-100 um, and the size range of the interval between any two adjacent meshes is 5 um-100 um.

In a possible embodiment, the pattern of barrier structures comprises a plurality of stripes parallel to each other; wherein, in the array direction of a plurality of bars, the size range of arbitrary bar is 5um ~ 100um, and the size range of the interval between two arbitrary adjacent bars is 5um ~ 100 um.

In a possible embodiment, the polymerizing the polymerizable material in at least one of the plurality of pixel regions based on the blocking structure includes: and irradiating the polymerizable material in at least one pixel region with ultraviolet light through the barrier structure.

In a possible embodiment, the liquid crystal comprises: one or more liquid crystal molecules; and the polymerizable material comprises: one or more photopolymerizable monomer molecules and a photoinitiator.

In a possible embodiment, the mass percentage of the photopolymerizable monomer molecule or molecules in the mixture of liquid crystal and polymerizable material is in the range of 10% or less.

In a possible embodiment, the mass percentage of the photopolymerizable monomer molecule or molecules in the mixture of liquid crystal and polymerizable material is in the range of 3% to 9%.

In a possible embodiment, after the polymerizing the polymerizable material in at least one of the plurality of pixel regions based on the blocking structure, the method further includes: forming an upper barrier layer on a surface of the upper substrate facing away from the liquid crystal layer, wherein the upper barrier layer completely covers the surface of the upper substrate facing away from the liquid crystal layer; and/or forming a lower barrier layer on the surface of the lower substrate, which faces away from the liquid crystal layer, wherein the lower barrier layer completely covers the surface of the lower substrate, which faces away from the liquid crystal layer.

Drawings

Fig. 1 is a schematic structural diagram of a display panel provided in an embodiment of the present disclosure.

Fig. 2(a) is a schematic view of a projection of a pixel region of a display panel on a lower substrate according to an embodiment of the disclosure.

Fig. 2(b) is another schematic view of a projection of a pixel region of a display panel on a lower substrate according to an embodiment of the disclosure.

Fig. 2(c) is another schematic view of a projection of a pixel region of a display panel on a lower substrate according to an embodiment of the disclosure.

Fig. 2(d) is a schematic view of a projection of a plurality of pixel regions of a display panel on a lower substrate according to an embodiment of the disclosure.

Fig. 3(a) is a schematic structural diagram of a display panel provided in the embodiment of the present disclosure.

Fig. 3(b) is a schematic structural diagram of a display panel provided in the embodiment of the present disclosure.

Fig. 4 is a flowchart illustrating a step of a method for manufacturing a display panel according to an embodiment of the disclosure.

Fig. 5 is a schematic flow chart of a method for manufacturing a display panel according to an embodiment of the disclosure.

Fig. 6 is another schematic flow chart of a method for manufacturing a display panel according to an embodiment of the present disclosure.

Fig. 7(a) is a schematic diagram of a pattern of a barrier structure used in a method for manufacturing a display panel according to an embodiment of the present disclosure.

Fig. 7(b) is another schematic diagram of a pattern of a barrier structure used in a method for manufacturing a display panel according to an embodiment of the present disclosure.

Fig. 7(c) is still another schematic diagram of a pattern of a barrier structure used in a method for manufacturing a display panel according to an embodiment of the present disclosure.

Fig. 8 is a graph of a relationship between a display contrast ratio of each display panel manufactured using barrier structures having different patterns and a driving voltage of a liquid crystal layer in the embodiment of the present disclosure.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The inventors of the present invention have found that various problems occur in transparent display of a liquid crystal display device, an organic semiconductor light emitting diode display device, and the like. For example, the liquid crystal display device has a low light transmittance of about 20% at the maximum; although the Light transmittance of an OLED (Organic Light-Emitting Diode) display device can reach more than 60%, the problems of luminance attenuation and short service life are obvious; both the electrochromic display device and the electrowetting display device have relatively high light transmittance but have a relatively slow response speed, requiring tens or hundreds of milliseconds. In addition, most transparent display panels exhibit a transparent state only when a voltage is applied, and an opaque state when no voltage is applied. Accordingly, there is an increasing demand for a new transparent display technology that is transparent when no voltage is applied and has high transparency. For example, the transparent display technology can be applied to the aspects of vehicle-mounted application, intelligent wearable application and the like.

Further, the inventors have found that a waveguide transparent display device based on PSLC (Polymer Stabilized Liquid Crystal) or PDLC (Polymer Dispersed Liquid Crystal) has a remarkable advantage in transparency, response speed, color display, and the like. The PSLC display panel is characterized in that: the liquid crystal box can be used as a light guide plate and can also be used for displaying. The light source can be incident from the side face of the liquid crystal box, when display is not needed, driving voltage does not need to be provided for liquid crystal, and the display box is in a transparent state (the transparency is 80-90%); when display is needed, applying a driving voltage to a set area to correspondingly deflect liquid crystal molecules in the area; under the influence of the polymer, the liquid crystal molecules are disorderly oriented, so that light is scattered and emitted from the light emitting surface of the liquid crystal box, and the display is realized. In addition, the display response speed of the waveguide transparent display device based on the PSLC is very high and can reach about 1ms to 2 ms. However, the waveguide transparent display device based on the PSLC has a problem that the contrast is low to affect the display effect.

At least to solve the above problems, some embodiments of the present disclosure provide a display panel, a display device, and a display panel manufacturing method.

The embodiment of the disclosure provides a display panel, and fig. 1 shows a schematic structural diagram of the display panel provided by the embodiment of the disclosure. The display panel may include an upper substrate 1, a lower substrate 2, and a liquid crystal layer 3 between the upper substrate 1 and the lower substrate 2, the liquid crystal layer 3 including liquid crystal and a high molecular polymer (i.e., the liquid crystal layer 3 includes two materials: a liquid crystal material and a high molecular polymer material), wherein: the liquid crystal layer 3 has a plurality of pixel regions (for convenience of description, fig. 1 shows a cross section of the display panel corresponding to only 1 pixel region), and at least one of the plurality of pixel regions includes a primary scattering region 31 and a secondary scattering region 32; the first high molecular polymer located in the main scattering region 31 has a first molecular degree of polymerization, and the second high molecular polymer located in the auxiliary scattering region 32 has a second molecular degree of polymerization, and the second molecular degree of polymerization is less than the first molecular degree of polymerization. That is, the polymerization degree of the high molecular polymer in the main scattering region 31 is higher, and the formed liquid crystal polymer network is more compact; the polymerization degree of the high molecular polymer in the auxiliary scattering region 32 is relatively low, and the formed liquid crystal polymer network is relatively loose.

In a pixel region, the liquid crystal polymer network in the main scattering region 31, in which the high molecular polymer has the first molecular polymerization degree, is denser, so that the scattering ability of the main scattering region 31 is stronger; in contrast, the liquid crystal polymer network in the auxiliary scattering region 32 in which the high molecular polymer has the second degree of molecular polymerization is relatively loose, and thus the scattering ability of the auxiliary scattering region 32 is weak. Thus, in the case where a side light source of the display panel (for example, the light source may be located near the side of the display panel shown in fig. 1, and specifically, the light source may be located near the side (for example, left side) of the liquid crystal layer 3 of the display panel shown in fig. 1) is lit, the main scattering area 31 of one pixel region may normally emit light; the light intensity of the light emitted from the auxiliary scattering region 32 is weak due to the reduced scattering ability, and compared with the bright-state display (the gray-scale value of the pixel is about 255), the reduced scattering ability of the auxiliary scattering region 32 has a greater effect on the dark-state display (the gray-scale value of the pixel is about 0), so that the residual refraction of the auxiliary scattering region 32 in one pixel region is lower, and the brightness is lower. Therefore, when the driving voltage is applied to the display panel to realize display, for the bright areas of the display screen, the primary scattering areas 31 of the pixel areas emit light normally, and the weakened degree of the light intensity of the secondary scattering areas 32 is not obvious, so the display screen of the areas is still bright; for the darker area of the display screen, the primary scattering area 31 of each pixel area emits light normally, but the degree of the light intensity of the secondary scattering area 32 is weakened to a greater extent, so that the display screen of the area is darker, and the display contrast is improved.

According to the embodiment of the present disclosure, the shape, size, and angle of the auxiliary scattering region 32 in each pixel region and/or the second molecular polymerization degree (scattering ability) of the second high molecular polymer of the auxiliary scattering region 32 may be adjusted to achieve the ratio optimization of strong scattering and weak scattering, that is, to minimize the influence on the bright state display, but make the dark state display darker, thereby achieving the optimal contrast.

According to the embodiment of the present disclosure, as shown in fig. 2(a) and 2(b), there are two schematic views of a projection of one pixel region on the lower substrate 2. The orthographic projection of the secondary scattering areas 32 on the lower substrate 2 may be a grid, and the meshes of the grid may be rectangular. For example, the grid lines correspond to the regions where the degree of polymerization of the molecules is low (the auxiliary scattering regions 32), and the other hollow-out regions may correspond to the regions where the degree of polymerization of the molecules is high (the main scattering regions 31). In this case, the second molecular polymerization degree may be an average value of the molecular polymerization degrees of the high molecular polymers in a region where the molecular polymerization degree is low corresponding to the grid line. As shown in fig. 2(a), each side of the mesh may be parallel to each side of the projection of the pixel region on the lower substrate 2, respectively; as shown in fig. 2(b), each side of the mesh may be at a predetermined angle, for example, 45 degrees, with respect to each side of the projection of the pixel region on the lower substrate 2. In practice, the dimension d1 of any side length of the mesh can be 5um to 100um, and the dimension d2 of the interval between any two adjacent meshes can be 5um to 100 um. In addition, the mesh of the mesh may also be a diamond, a trapezoid, an irregular polygon, etc., and this embodiment is not limited in this respect.

According to the embodiment of the present disclosure, as shown in fig. 2(c), it is another schematic view of a projection of one pixel region on the lower substrate 2. The auxiliary scattering region 32 may further include a plurality of sub-auxiliary scattering regions, and projections of the plurality of sub-auxiliary scattering regions on the lower substrate 2 are parallel to each other; in the arrangement direction of the sub-auxiliary scattering regions, the size d3 of any sub-auxiliary scattering region ranges from 5um to 100um, and the size d4 of the interval between any two adjacent sub-auxiliary scattering regions ranges from 5um to 100 um.

According to the embodiment of the present disclosure, as shown in fig. 2(d), it is a schematic diagram of projections of a plurality of pixel regions on the lower substrate 2. Wherein 31 is a main scattering region of a pixel region, 32 is an auxiliary scattering region of a pixel region, and 33 is a metal wire region. The shape, size and angle of the auxiliary scattering region 32 of each pixel region are not particularly limited in the embodiment of the present disclosure; the shape, size or angle of the secondary scattering regions 32 may be the same or different for any two pixel regions. In particular implementations, the shape, size, and angle of the secondary scattering region 32 to achieve optimal contrast can be determined experimentally. In order to ensure the scattering intensity while enhancing the contrast, the ratio of the area of the main scattering region 31 of one pixel region projected onto the lower substrate 2 to the area of the pixel region projected onto the lower substrate 2 may be 50% or more, that is, the ratio of the area of the sub scattering region 32 of the pixel region projected onto the lower substrate 2 to the area of the pixel region projected onto the lower substrate 2 may be 50% or less.

According to the embodiment of the present disclosure, the liquid crystal layer 3 may include liquid crystal and polymerizable material before the main scattering region 31 and the auxiliary scattering region 32 of the pixel region are formed; wherein the liquid crystal may include one or more liquid crystal molecules and the polymerizable material may include one or more photopolymerizable monomer molecules and a photoinitiator. The photopolymerizable monomer molecules and the liquid crystal molecules are compatible, so that when the polymerizable material is polymerized through the barrier structure with the set pattern to form a high polymer, liquid crystal in the liquid crystal layer 3 and the high polymer form a liquid crystal polymer network, and finally PSLC is formed; in addition, in one pixel region, the polymerization degree of the high molecular polymer formed in the shielded region is different from that of the high molecular polymer formed in the unshielded region, that is, the density degree of the liquid crystal polymer network in the shielded region is different from that in the unshielded region, so that the secondary scattering region 32 and the primary scattering region 31 with different scattering abilities are formed. Further, it is to be understood that the polymerizable material comprising one or more photopolymerizable monomer molecules and a photoinitiator may or may not have monomer molecules in the high molecular weight polymer and may or may not have a photoinitiator after undergoing a polymerization process to form the high molecular weight polymer.

According to the embodiments of the present disclosure, the liquid crystal molecules may have a dielectric constant ε in the long axis direction_∥Dielectric constant epsilon with minor axis direction_⊥Materials with large differences, e.g. epsilon of liquid crystal molecules_∥And epsilon_⊥The absolute value of the difference of (b) may not be less than the set threshold. In addition, the photopolymerizable monomer molecules generally account for less than 10% by mass of the mixture of liquid crystal and polymerizable material, and may range from 3% to 9% by mass, for example.

According to the embodiment of the present disclosure, the blocking structure having the set pattern may be a mask covering any one of the upper substrate 1 and the lower substrate 2, and an orthogonal projection of the pattern of the mask on the lower substrate 2 coincides with an orthogonal projection of the secondary scattering region 32 on the lower substrate 2.

Fig. 3(a) shows another schematic structural diagram of a display panel provided by an embodiment of the present disclosure. According to the embodiment of the present disclosure, the barrier structure having the set pattern may also be an upper absorption layer 12 on the upper substrate 1 and/or a lower absorption layer 22 on the lower substrate 2; wherein the orthographic projection of the upper absorbing layer 12 on the lower substrate 2 coincides with the orthographic projection of the secondary scattering region 32 on the lower substrate 2, and/or the orthographic projection of the lower absorbing layer 22 on the lower substrate 2 coincides with the orthographic projection of the secondary scattering region 32 on the lower substrate 2.

That is, the absorption layers 12 and 22 having a set pattern may be formed in the substrate, and one of the upper absorption layer 12 and the lower absorption layer 22 may serve as a barrier structure for implementing a self-aligned selective process when a polymerizable material in the pixel region is subjected to a polymerization process, thereby forming the primary scattering region 31 and the secondary scattering region 32 in the pixel region.

According to an embodiment of the present disclosure, the material of each of the absorption layers 12 and 22 may include one or more of a salicylate-based material, a benzophenone-based material, a benzotriazole-based material, a substituted acrylonitrile-based material, a triazine-based material, and a hindered amine-based material.

According to the embodiment of the present disclosure, the

absorption layer

12 or 22 may be located outside the corresponding substrate, and may also be located in the corresponding substrate. For example, in fig. 3(a), the upper absorption layer 12 may be located between the upper transparent electrode layer 14 and the upper liquid crystal alignment layer 15 of the upper substrate 1, and the lower absorption layer 22 may be located between the control circuit layer 26 and the lower transparent electrode layer 24 of the lower substrate 2.

According to the embodiment of the present disclosure, the polymerizable material in the liquid crystal layer 3 is subjected to a polymerization process to form a high molecular polymer, which may be a transmission barrier structure, and the liquid crystal layer 3 is subjected to ultraviolet light UV irradiation, infrared irradiation, or heating. Furthermore, the transmittance of UV irradiation, infrared irradiation or heat can be adjusted by adjusting the composition, thickness, etc. of the blocking structure, so as to adjust the degree of polymerization of the high molecular polymer formed in the blocked region, i.e., adjust the degree of densification of the liquid crystal polymer network in the auxiliary scattering region 32, thereby achieving the ratio optimization of strong scattering and weak scattering, and achieving the optimal contrast.

Fig. 3(b) shows another schematic structural diagram of a display panel provided by the embodiment of the disclosure. According to the embodiment of the present disclosure, in order to enhance the stability of the display panel provided by the embodiment of the present disclosure in use, the display panel may further include an upper barrier layer 11 on a surface of the upper substrate 1 facing away from the liquid crystal layer 3 and/or a lower barrier layer 21 on a surface of the lower substrate 2 facing away from the liquid crystal layer 3; wherein the upper barrier layer 11 completely covers a surface of the upper substrate 1 facing away from the liquid crystal layer 3 (i.e., an upper surface of the upper substrate 1), and/or the lower barrier layer 21 completely covers a surface of the lower substrate 2 facing away from the liquid crystal layer 3 (i.e., a lower surface of the lower substrate 2). For example, in fig. 3(b), the upper barrier layer 11 is located on the outer side of the upper substrate 1 (the side facing away from the liquid crystal layer 3), the lower barrier layer 21 is located on the outer side of the lower substrate 2 (the side facing away from the liquid crystal layer 3), and the upper barrier layer 11 covers the entire upper substrate 1 and the lower barrier layer 21 covers the entire lower substrate 2.

That is, in order to prevent the materials in the liquid crystal layer 3 from being affected by ultraviolet rays in natural light when the display panel is used daily, further molecular polymerization occurs, resulting in a change in the difference between the degree of molecular polymerization of the high molecular polymer in the auxiliary scattering region 32 and the main scattering region 31, that is, a change in the difference between the degree of densification of the liquid crystal polymer network in the auxiliary scattering region 32 and the main scattering region 31, thereby affecting the display contrast, the barrier layers 11 and 21 may be provided on the upper substrate 1 and the lower substrate 2, respectively, after the main scattering region 31 and the auxiliary scattering region 32 are formed, to block ultraviolet rays from irradiating each pixel region, thereby further enhancing the reliability of the display panel in use.

According to an embodiment of the present disclosure, the material of each of the barrier layers 11 and 21 may include one or more of a salicylate-based material, a benzophenone-based material, a benzotriazole-based material, a substituted acrylonitrile-based material, a triazine-based material, and a hindered amine-based material. In specific implementation, the manufacturing process of the barrier layers 11 and 21 may adopt spin coating followed by photolithography, or mask-based spray coating, or mask-based evaporation, etc.

According to an embodiment of the present disclosure, as shown in fig. 3(a), the upper substrate 1 may further include, from top to bottom, in addition to the barrier layers 11 and 21: an upper substrate 13, an upper transparent electrode layer 14, and an upper liquid crystal alignment layer 15; the lower substrate 2 may further include, from bottom to top: a lower substrate 23, a control circuit layer 26, a lower transparent electrode layer 24, and a lower liquid crystal alignment layer 25; the control circuit layer 26 may include a metal wire, a passivation layer, an active layer, a metal wire layer, a passivation layer, a metal electrode layer, and the like. The structures of the

substrates

1 and 2 except the barrier layers 11 and 21 may be similar to those of the related art, and the present embodiment is not described herein again.

The embodiment of the disclosure also provides a display device, which may include the display panel provided by the embodiment of the disclosure. The display device also has the advantage of higher display contrast.

According to an embodiment of the present disclosure, the display device may further include a plurality of monochromatic light sources configured to time-divisionally provide backlights of different wavelengths to the display panel. In practice, the plurality of monochromatic light sources may be disposed on the side of the display device (e.g., the left side as viewed in FIG. 1) or may be disposed on the back of the display device (e.g., the lower side as viewed in FIG. 1). In the case where the display device includes a plurality of monochromatic light sources, the display device can realize color display without including a color film.

According to the embodiment of the disclosure, the display device can be any product or component with a display function, such as a waveguide transparent display panel based on a PSLC, a waveguide transparent display module based on a PSLC, a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, and a navigator.

The embodiment of the present disclosure also provides a method for manufacturing the display panel provided by the embodiment of the present disclosure, as shown in fig. 4. Fig. 4 is a flowchart of the method for manufacturing the display panel, which may include steps S41 and S42.

In step S41, a liquid crystal cell is formed, wherein the liquid crystal cell may include an upper substrate 1, a lower substrate 2, and a liquid crystal layer 3 between the upper substrate 1 and the lower substrate 2, the liquid crystal layer 3 may include a liquid crystal and a polymerizable material, and the liquid crystal layer 3 has a plurality of pixel regions.

According to an embodiment of the present disclosure, the forming of the liquid crystal cell in step S41 may specifically include: depositing an upper transparent electrode layer 14 on a surface of the upper substrate 13 close to the lower substrate 2, wherein the material of the upper transparent electrode layer 14 may be a highly transparent conductive material, such as ITO (Indium Tin Oxide), and the thickness of the upper transparent electrode layer 14 may be generally 50nm to 200 nm; a gap control column (not shown in fig. 3(a) and fig. 6) is fabricated on the surface of the upper transparent electrode layer 14 close to the lower substrate 2, the height of the gap control column may be generally 2um to 6um, and the gap control column may be disposed at the boundary between any two adjacent pixel regions for maintaining the distance between the upper substrate 1 and the lower substrate 2; then, an upper liquid crystal alignment layer 15 is coated on a surface of the upper transparent electrode layer 14 adjacent to the lower substrate 2, and alignment is completed by a rubbing or photo-alignment technique, thereby forming the upper substrate 1. Forming a control circuit layer 26 on the surface of the lower substrate 23 close to the upper substrate 1, wherein the control circuit layer 26 may include a metal wire, a passivation protection layer, an active layer, a metal wire layer, a passivation protection layer, a metal electrode layer, and the like; then, a lower transparent electrode layer 24 and a lower liquid crystal alignment layer 25 are sequentially formed on the surface of the control circuit layer 26 adjacent to the upper substrate 1, thereby forming the lower substrate 2. After the

substrates

1 and 2 are completed, a mixture of liquid crystal and polymerizable material may be dropped in the pair-cell structure of the substrates 1 and 2 (i.e., between the substrates 1 and 2) by an ODF (One Drop Filling) process or a VIF (Vacuum Infusion) process to form the liquid crystal layer 3, thereby completing the fabrication of the liquid crystal cell. The thickness of the liquid crystal cell may range from 2 μm to 10 μm, for example from 3 μm to 6 μm. The thickness of the liquid crystal cell can also be increased or decreased according to the use requirement, and the embodiment is not limited herein.

According to the embodiment of the present disclosure, the liquid crystal in the liquid crystal layer 3 may include one or more kinds of liquid crystal molecules; the polymerizable material may include one or more photopolymerizable monomer molecules and a photoinitiator. The photopolymerizable monomer molecules and the liquid crystal molecules are compatible, so that when the polymerizable material is polymerized to form the high polymer in step S42, the liquid crystal in the liquid crystal layer 3 and the high polymer form a liquid crystal polymer network, and finally the PSLC is formed; in addition, in one pixel region, the polymerization degree of the high molecular polymer formed in the shielded region is different from that of the high molecular polymer formed in the unshielded region, that is, the density degree of the liquid crystal polymer network in the shielded region is different from that in the unshielded region, so that the secondary scattering region 32 and the primary scattering region 31 with different scattering abilities are formed.

In accordance with embodiments of the present disclosure, epsilon may be used for the liquid crystal molecules_∥And epsilon_⊥Materials with large differences, e.g. epsilon of liquid crystal molecules_∥And epsilon_⊥The absolute value of the difference of (b) may not be less than the set threshold. In addition, the mass proportion of the photopolymerizable monomer molecules in the mixture of the liquid crystal and the polymerizable material is generally 10% or less, and for example, the mass percentage may range from 3% to 9%.

In step S42, based on the blocking structure, performing a polymerization process on the polymerizable material in at least one of the plurality of pixel regions, such that a region of the at least one pixel region that is blocked by the pattern of the blocking structure forms the secondary scattering region 32, and a region that is not blocked by the pattern of the blocking structure forms the primary scattering region 31; the first high molecular polymer formed by polymerizing the polymerizable material in the main scattering region 31 has a first molecular polymerization degree, and the second high molecular polymer formed by polymerizing the polymerizable material in the auxiliary scattering region 32 has a second molecular polymerization degree, wherein the second molecular polymerization degree is smaller than the first molecular polymerization degree.

As described above, the degree of density of the liquid crystal polymer network formed by the liquid crystal and the high molecular polymer may determine the scattering ability of the PSLC, and therefore, in one pixel region, the liquid crystal polymer network in the main scattering region 31 where the high molecular polymer has the first molecular polymerization degree is denser, so that the scattering ability of the main scattering region 31 is stronger; in contrast, the liquid crystal polymer network in the auxiliary scattering region 32 in which the high molecular polymer has the second degree of molecular polymerization is relatively loose, and thus the scattering ability of the auxiliary scattering region 32 is weak. Thus, in the case where the side light source of the display panel is turned on, the main diffusion area 31 of one pixel area can normally emit light; the light intensity of the light emitted from the auxiliary scattering region 32 is weak due to the reduced scattering ability, and the reduced scattering ability of the auxiliary scattering region 32 has a greater effect on the dark state display (the gray value of the pixel is close to or equal to 0) than the bright state display (the gray value of the pixel is close to or equal to 255), so that the residual refraction of the auxiliary scattering region 32 in one pixel region is lower, and the brightness is lower. Therefore, when the driving voltage is applied to the display panel to realize display, for the bright areas of the display screen, the primary scattering areas 31 of the pixel areas emit light normally, and the weakened degree of the light intensity of the secondary scattering areas 32 is not obvious, so the display screen of the areas is still bright; for the darker area of the display screen, the primary scattering area 31 of each pixel area emits light normally, but the degree of the light intensity of the secondary scattering area 32 is weakened to a greater extent, so that the display screen of the area is darker, and the display contrast is improved.

According to the embodiment of the present disclosure, in order to ensure the scattering intensity while improving the contrast, the ratio of the orthographic projection area of the main scattering region 31 of one pixel region on the lower substrate 2 to the orthographic projection area of the pixel region on the lower substrate 2 may be 50% or more, that is, the ratio of the orthographic projection area of the auxiliary scattering region 32 of the pixel region on the lower substrate 2 to the orthographic projection area of the pixel region on the lower substrate 2 is 50% or less.

According to the embodiment of the present disclosure, as shown in fig. 5, the blocking structure in step S42 may be a mask covering any one of the upper substrate 1 and the lower substrate 2, and an orthogonal projection of a pattern of the mask on the lower substrate 2 coincides with an orthogonal projection of the secondary scattering region 32 on the lower substrate 2.

According to the embodiment of the present disclosure, as shown in fig. 6, the blocking structure in step S42 may also be the absorption layer 12 and/or 22 located on at least one of the upper substrate 1 and the lower substrate 2, and the orthographic projection of the

absorption layer

12 or 22 on the lower substrate 2 coincides with the orthographic projection of the secondary scattering region 32 on the lower substrate 2.

According to an embodiment of the present disclosure, if the barrier structure is the absorption layer 12 and/or 22 on at least one of the upper substrate 1 and the lower substrate 2, before the step S42 performing a polymerization process on the polymerizable material in at least one pixel region based on the barrier structure, the method may further include: an upper absorption layer 12 is formed on the upper substrate 1, and/or a lower absorption layer 22 is formed on the lower substrate 2. In specific implementations, the absorption layers 12 and 22 can be formed by photolithography after spin coating, or by spray coating based on a mask, or by evaporation coating based on a mask.

That is, in forming the liquid crystal cell, the absorption layers 12 and 22 having a set pattern may be formed in the substrate, and one of the upper absorption layer 12 and the lower absorption layer 22 may serve as a barrier structure for implementing a self-aligned selective process when a polymerizable material in the pixel region is subjected to a polymerization process, thereby forming the main scattering region 31 and the sub scattering region 32 in the pixel region.

According to the embodiment of the present disclosure, the

absorption layer

In addition, since the upper absorption layer 12 and the lower absorption layer 22 are disposed on the corresponding substrates, the upper absorption layer 12 and the lower absorption layer 22 can also prevent the material in the sub-scattering region 32 of each pixel region of the liquid crystal layer 3 from being affected by the ultraviolet rays in the natural light and further undergoing molecular polymerization when the display panel is used daily, which causes the second molecular polymerization degree of the second high molecular polymer in the sub-scattering region 32 to become large, and further causes the density degree of the liquid crystal polymer network formed in the sub-scattering region 32 to become large, thereby affecting the display contrast and enhancing the reliability of the display panel in use.

According to an embodiment of the present disclosure, as shown in fig. 7(a) and 7(b), the pattern of the barrier structures may be a grid, and the meshes of the grid may be rectangular. As shown in fig. 7(a), the sides of the mesh may be respectively parallel to the sides of the orthographic projection of the pixel regions on the plane of the blocking structures (not shown in fig. 7 (a)); as shown in fig. 7(b), the sides of the mesh may also be at a set angle, e.g. 45 degrees, respectively to the sides of the orthographic projection of the pixel area on the plane of the blocking structure (not shown in fig. 7 (b)). In practice, the dimension d5 of any side length of the mesh can be 5um to 100um, and the dimension d6 of the interval between any two adjacent meshes can be 5um to 100 um. In addition, the mesh of the mesh may also be a diamond, a trapezoid, an irregular polygon, etc., and this embodiment is not limited in this respect.

According to an embodiment of the present disclosure, as shown in fig. 7(c), the pattern of the barrier structures may further include a plurality of bars parallel to each other; wherein, in the arrangement direction of the plurality of strips, the size d7 range of any strip is 5 um-100 um, and the size d8 range of the interval between any two adjacent strips is 5 um-100 um.

As can be seen from the above, the orthographic projection of the auxiliary scattering region 32 in the pixel region on the lower substrate 2 coincides with the orthographic projection of the pattern of the blocking structure on the lower substrate 2, and therefore, the shape, size and angle of the auxiliary scattering region 32 can be adjusted by adjusting the shape, size and angle of the pattern of the blocking structure, so as to achieve the matching optimization of strong scattering and weak scattering, that is, to reduce the influence on bright state display as much as possible, but to make dark state display darker, thereby achieving the optimal contrast. As shown in fig. 8, which is a graph of the relationship between the display contrast of each display panel manufactured using the barrier structures having different patterns and the driving voltage of the liquid crystal layer 3. When the setting process is performed on the first display panel, the barrier structure (corresponding to the curve indicated by "None" in fig. 8) is not used, that is, the molecular polymerization degree of each pixel region of the liquid crystal layer 3 of the first display panel is uniform, excluding the main scattering region 31 and the auxiliary scattering region 32. When the setting process is performed on the second display panel, a pattern of a barrier structure (which may be referred to as "Mask 1") used is as shown in fig. 7(c) (corresponding to a curve indicated by "Mask 1" in fig. 8), and the pattern of the Mask1 includes a plurality of bars parallel to each other, each bar having a size of 5um in an arrangement direction of the plurality of bars, and a size of a space between each adjacent bar also being 5 um. When the setting process is performed on the third display panel, a pattern of a barrier structure (which may be referred to as "Mask 2") is used as shown in fig. 7(a) (corresponding to a curve indicated by "Mask 2" in fig. 8), the pattern of the Mask 2 is a grid, the meshes of the grid are squares, each side length of each mesh is 5um, and the interval between every two adjacent meshes is also 5 um; the sides of the mesh are parallel to the sides of the pixel area, respectively. When the setting process is performed on the fourth display panel, the pattern of the blocking structure (which may be referred to as "Mask 3") used is as shown in fig. 7(b), the shape and size of the pattern of the Mask 3 are the same as those of the pattern of the Mask 2, and only the edges of the mesh of the pattern of the Mask 3 form 45-degree angles with the edges of the projection of the pixel region on the plane where the blocking structure is located.

As can be seen from fig. 7, each of the curves denoted by "Mask 1", "Mask 2", and "Mask 3" shows a significant improvement in contrast as compared with the curve denoted by "None"; at higher driving voltages, the display contrast of the curves denoted by "Mask 2" and "Mask 3" can be increased to 1.3 to 1.4 times that of the curve denoted by "None". It follows that the display contrast can be further optimized by optimizing the pattern design of the barrier structures, i.e. optimizing the shape, size and angle of the pattern, etc.

According to the embodiment of the present disclosure, the step S42 of performing polymerization treatment on the polymerizable material in at least one pixel region based on the blocking structure may specifically include: the polymerizable material in at least one pixel region is UV irradiated through the blocking structure. That is, different degrees of photopolymerization of the polymerizable material in different regions in one pixel region can be achieved based on the blocking structure and UV irradiation.

According to the embodiment of the present disclosure, the transmittance of UV irradiation can be adjusted by adjusting the components, thickness, etc. of the blocking structure, so as to adjust the degree of polymerization of the high molecular polymer formed in the blocked region, i.e., adjust the degree of compactness of the liquid crystal polymer network in the auxiliary scattering region 32, thereby achieving the ratio optimization of strong scattering and weak scattering, and achieving the optimal contrast.

According to the embodiment of the present disclosure, the step S42 of performing a polymerization process on the polymerizable material in the at least one pixel region based on the blocking structure may also include: irradiating the polymerizable material in the at least one pixel region with infrared rays through the barrier structure; alternatively, the polymerizable material in at least one pixel region is heated by the barrier structure. That is, if the liquid crystal layer 3 includes liquid crystal molecules, polymerizable monomer molecules, and a suitable initiator, the polymerizable material in the pixel region may also be selectively polymerized by infrared irradiation or heating. The polymerizable materials in different regions in one pixel region can be polymerized to different degrees only based on the blocking structure and a suitable polymerization manner, and the embodiment does not limit the polymerization manner at all.

According to an embodiment of the present disclosure, after the step S42 performing the polymerization process on the polymerizable material in the at least one pixel region based on the barrier structure, the method may further include: forming an upper barrier layer 11 on the surface of the upper substrate 1 facing away from the liquid crystal layer 3, and/or forming a lower barrier layer 11 on the surface of the lower substrate 2 facing away from the liquid crystal layer 3; wherein the upper barrier layer 11 completely covers the surface of the upper substrate 1 facing away from the liquid crystal layer 3, and/or the lower barrier layer 21 completely covers the surface of the lower substrate 2 facing away from the liquid crystal layer 3. For example, in fig. 3(b), the upper barrier layer 11 is located on the outer side of the upper substrate 1 (the side facing away from the liquid crystal layer 3), the lower barrier layer 21 is located on the outer side of the lower substrate 2 (the side facing away from the liquid crystal layer 3), and the upper barrier layer 11 covers the entire upper substrate 1 and the lower barrier layer 21 covers the entire lower substrate 2.

According to an embodiment of the present disclosure, the material of each of the barrier layers 11 and 21 may include one or more of a salicylate-based material, a benzophenone-based material, a benzotriazole-based material, a substituted acrylonitrile-based material, a triazine-based material, and a hindered amine-based material.

It should be understood that the "projections" in this disclosure may all be orthographic projections. The above-described embodiments of the disclosure may be combined with each other without significant conflict.

In this disclosure, the terms "first," "second," and the like are used only to distinguish one feature from another, and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless expressly limited otherwise.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the following claims.

Claims

A display panel comprising an upper substrate, a lower substrate, and a liquid crystal layer between the upper substrate and the lower substrate, the liquid crystal layer comprising liquid crystal and high molecular polymer, wherein:

the display panel is provided with a plurality of pixel regions, and at least one pixel region in the plurality of pixel regions comprises a main scattering region and an auxiliary scattering region; the first high molecular polymer positioned in the main scattering region has a first molecular polymerization degree, and the second high molecular polymer positioned in the auxiliary scattering region has a second molecular polymerization degree, wherein the second molecular polymerization degree is less than the first molecular polymerization degree.
The display panel of claim 1, wherein a ratio of an area of an orthogonal projection of the main scattering region on the lower substrate to an area of an orthogonal projection of each of the at least one pixel region on the lower substrate is 50% or more.
The display panel according to claim 1 or 2, wherein an orthographic projection of the secondary scattering region on the lower substrate is a grid, and a mesh of the grid is rectangular; the size range of any side length of the meshes is 5 um-100 um, and the size range of the interval between any two adjacent meshes is 5 um-100 um.
The display panel according to any one of claims 1 to 3, wherein the auxiliary scattering region comprises a plurality of sub-auxiliary scattering regions, and orthographic projections of the sub-auxiliary scattering regions on the lower substrate are parallel to each other; wherein, in the direction of arrangement of a plurality of sub-auxiliary scattering regions, the size range of any sub-auxiliary scattering region is 5um ~ 100um, and the size range of the interval between any two adjacent sub-auxiliary scattering regions is 5um ~ 100 um.
The display panel according to any one of claims 1 to 4, further comprising an upper absorption layer on the upper substrate, wherein an orthographic projection of the upper absorption layer on the lower substrate coincides with an orthographic projection of the secondary scattering region on the lower substrate;

and/or a lower absorption layer positioned on the lower substrate, wherein the orthographic projection of the lower absorption layer on the lower substrate is superposed with the orthographic projection of the auxiliary scattering region on the lower substrate.
The display panel according to any one of claims 1 to 5, further comprising an upper barrier layer on a surface of the upper substrate facing away from the liquid crystal layer, the upper barrier layer completely covering a surface of the upper substrate facing away from the liquid crystal layer;

and/or, be located the lower barrier layer on the surface of infrabasal plate back to the liquid crystal layer, the lower barrier layer covers completely the surface of infrabasal plate back to the liquid crystal layer.
A display device comprising the display panel according to any one of claims 1 to 6.
The display device of claim 7, further comprising a plurality of monochromatic light sources configured to time-share the backlight providing different wavelengths to the display panel.
A display panel manufacturing method, comprising:

forming a liquid crystal cell, wherein the liquid crystal cell comprises an upper substrate, a lower substrate and a liquid crystal layer positioned between the upper substrate and the lower substrate, the liquid crystal layer comprises liquid crystal and polymerizable materials, and the liquid crystal layer is provided with a plurality of pixel regions; and

performing polymerization treatment on the polymerizable material in at least one pixel region of the plurality of pixel regions based on a blocking structure, so that a region, shielded by the pattern of the blocking structure, of the at least one pixel region forms a secondary scattering region, and a region, not shielded by the pattern of the blocking structure, forms a primary scattering region;

wherein a first high molecular polymer formed by polymerization of the polymerizable material in the primary scattering region has a first molecular polymerization degree, and a second high molecular polymer formed by polymerization of the polymerizable material in the secondary scattering region has a second molecular polymerization degree, and the second molecular polymerization degree is smaller than the first molecular polymerization degree.
The display panel manufacturing method according to claim 9, wherein a ratio of an area of an orthogonal projection of the main scattering region on the lower substrate to an area of an orthogonal projection of each of the at least one pixel region on the lower substrate is 50% or more.
The display panel manufacturing method according to claim 9 or 10, wherein the blocking structure is a mask covering the upper substrate and/or the lower substrate, and an orthogonal projection of a pattern of the mask on the lower substrate coincides with an orthogonal projection of the secondary scattering region on the lower substrate.
The display panel manufacturing method according to claim 9 or 10, wherein the blocking structure is an upper absorption layer on the upper substrate, an orthographic projection of the upper absorption layer on the lower substrate coincides with an orthographic projection of the secondary scattering region on the lower substrate, and/or a lower absorption layer on the lower substrate, an orthographic projection of the lower absorption layer on the lower substrate coincides with an orthographic projection of the secondary scattering region on the lower substrate.
The display panel manufacturing method of any one of claims 9 to 12, wherein the pattern of the barrier structures is a grid, and the meshes of the grid are rectangular; the size range of any side length of the meshes is 5 um-100 um, and the size range of the interval between any two adjacent meshes is 5 um-100 um.
The display panel manufacturing method according to any one of claims 9 to 13, wherein the pattern of the barrier structures includes a plurality of stripe shapes parallel to each other; in the arrangement direction of the plurality of bars, the size range of any bar is 5 um-100 um, and the size range of the interval between any two adjacent bars is 5 um-100 um.
The display panel manufacturing method according to any one of claims 9 to 14, wherein the barrier structure-based polymerization treatment of the polymerizable material in at least one of the plurality of pixel regions includes:

and irradiating the polymerizable material in the at least one pixel region with ultraviolet light through the barrier structure.
The display panel manufacturing method according to any one of claims 9 to 15, wherein the liquid crystal includes: one or more liquid crystal molecules; and

the polymerizable material includes: one or more photopolymerizable monomer molecules and a photoinitiator.
The display panel manufacturing method according to claim 16, wherein the one or more photopolymerizable monomer molecules account for a range of 10% or less by mass in the mixture of the liquid crystal and the polymerizable material.
The display panel manufacturing method according to claim 17, wherein the one or more photopolymerizable monomer molecules account for a range of 3% to 9% by mass in the mixture of the liquid crystal and the polymerizable material.
The display panel manufacturing method according to any one of claims 9 to 18, further comprising, after the barrier structure-based polymerization treatment of the polymerizable material in at least one of the plurality of pixel regions, the method:

forming an upper barrier layer on a surface of the upper substrate facing away from the liquid crystal layer, wherein the upper barrier layer completely covers the surface of the upper substrate facing away from the liquid crystal layer; and/or

And forming a lower barrier layer on the surface of the lower substrate, which faces away from the liquid crystal layer, wherein the lower barrier layer completely covers the surface of the lower substrate, which faces away from the liquid crystal layer.