CN113299715A

CN113299715A - Display panel, preparation method thereof and display device

Info

Publication number: CN113299715A
Application number: CN202110558901.2A
Authority: CN
Inventors: 王英涛; 王新星; 彭宽军
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2021-05-21
Filing date: 2021-05-21
Publication date: 2021-08-24

Abstract

A display panel and a display device, the display panel comprising: at least one transmissive sub-pixel comprising a first driving structure layer and a light emitting unit, the display panel comprising, in a direction perpendicular to a display surface of the display panel: the liquid crystal display panel comprises a first substrate, a second substrate, a guest-host liquid crystal layer and an 1/4 wavelength phase delay layer, wherein the first substrate and the second substrate are oppositely arranged, the guest-host liquid crystal layer is arranged between the first substrate and the second substrate, and the 1/4 wavelength phase delay layer is arranged between the first substrate and the guest-host liquid crystal layer; the first driving structure layer and the light emitting unit are disposed between the first substrate and the 1/4 wavelength-phase retardation layer; the orthographic projection of the open area of the transmissive sub-pixel is located within the orthographic projection of the 1/4 wavelength phase retarder. The display panel provided by the embodiment has the advantages that the guest host liquid crystal layer and the 1/4 wavelength phase delay layer are arranged, and compared with a circular polarizer, the light emitting rate can be greatly improved, the display brightness is enhanced, the power consumption is reduced, and the service life of the display panel is prolonged.

Description

Display panel, preparation method thereof and display device

Technical Field

The present disclosure relates to display technologies, and particularly to a display panel, a method for manufacturing the display panel, and a display device.

Background

The current display technologies mainly include a transmissive mode, a reflective mode and a transflective mode, the transmissive mode is the most popular mode at present, however, the transmissive mode has the problems of high power consumption and poor display effect outdoors, while the reflective mode cannot well realize display in a dark room environment, and the transflective mode has good display effect indoors and outdoors, but because of low aperture ratio, the transflective technology is gradually abandoned with the increase of PPI.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The embodiment of the disclosure provides a display panel, a preparation method thereof and a display device, which are used for realizing indoor and outdoor display.

An embodiment of the present disclosure provides a display panel, including: at least one transmissive sub-pixel comprising a first driving structure layer and a light emitting unit, the display panel comprising, in a direction perpendicular to a display surface of the display panel: a first substrate and a second substrate disposed opposite each other, a guest-host liquid crystal layer disposed between the first substrate and the second substrate, and an 1/4 wavelength phase retardation layer disposed between the first substrate and the guest-host liquid crystal layer; the first driving structure layer and the light emitting unit are disposed between the first substrate and the 1/4 wavelength-phase retardation layer; the orthographic projection of the open area of the transmissive sub-pixel is located within the orthographic projection of the 1/4 wavelength phase retarder.

In an exemplary embodiment, the display panel further includes: at least one reflective sub-pixel comprising a reflective layer disposed between the first substrate and the 1/4 wavelength-phase retardation layer; an orthographic projection of the open area of the transmissive sub-pixel on a plane parallel to the first substrate is at least partially outside an orthographic projection of the reflective layer, which is within an orthographic projection of the 1/4 wavelength phase retarder layer.

In an exemplary embodiment, the reflective layer is disposed on a side of the light emitting unit away from the first substrate; or, the light-emitting unit comprises an organic light-emitting layer, and the reflecting layer is arranged on one side of the organic light-emitting layer close to the first substrate.

In an exemplary embodiment, the reflective sub-pixel further comprises: the transparent insulating layer and the semi-transparent and semi-reflective layer are sequentially arranged on one side, away from the first substrate, of the reflective layer; and the reflecting layer, the transparent insulating layer and the semi-transmitting and semi-reflecting layer form a resonant cavity, and the resonant cavity is set to emit light with the color corresponding to the reflective sub-pixel after the incident light is reflected for multiple times.

In an exemplary embodiment, the thicknesses of the transparent insulating layers of the reflective sub-pixels of different colors are different in a direction perpendicular to the first substrate.

In an exemplary embodiment, the display panel further includes: and the scattering layer is arranged on one side of the second substrate far away from the first substrate.

In an exemplary embodiment, at least a portion of a surface of the reflective layer on a side close to the second substrate is a rough surface, and the rough surface is configured to emit light incident on the rough surface in a form of scattered light.

In an exemplary embodiment, the display panel further includes: and the color film structure layer is arranged between the second substrate and the guest-host liquid crystal layer and comprises a plurality of color filtering units which correspond to the reflective sub-pixels one to one.

In an exemplary embodiment, the color filter structure layer further includes: and the color filter units correspond to the transmission type sub-pixels one by one.

In an exemplary embodiment, the display panel further includes: an encapsulation layer disposed between the light emitting cells and the 1/4 wavelength-phase retardation layer; a first electrode layer disposed between the first substrate and the guest-host liquid crystal layer, a second electrode layer disposed between the second substrate and the guest-host liquid crystal layer;

the reflective sub-pixel further comprises: a second driving structure layer arranged on the packaging layer and the 1/4 wave phase delay layer; or a second driving structure layer disposed between the second substrate and the guest-host liquid crystal layer.

In another aspect, an embodiment of the present disclosure provides a display device, including the display panel.

In another aspect, an embodiment of the present disclosure provides a method for manufacturing a display panel, where the display panel includes at least one transmissive sub-pixel, the method including:

sequentially forming a first driving structure layer and a light emitting unit of the transmissive sub-pixel on a first substrate;

forming an 1/4-wavelength phase delay layer on the side of the light-emitting unit away from the first substrate; the orthographic projection of the opening region of the transmissive sub-pixel is positioned in the orthographic projection of the 1/4 wavelength phase retardation layer;

forming a guest-host liquid crystal layer on the side of the 1/4 wavelength phase retardation layer away from the first substrate, or forming a guest-host liquid crystal layer on the second substrate; and forming the display panel by facing the first substrate and the second substrate.

The embodiment of the disclosure includes a display panel, a preparation method thereof and a display device, wherein the display panel comprises: at least one transmissive sub-pixel comprising a first driving structure layer and a light emitting unit, the display panel comprising, in a direction perpendicular to a display surface of the display panel: the liquid crystal display panel comprises a first substrate, a second substrate, a guest-host liquid crystal layer and an 1/4 wavelength phase delay layer, wherein the first substrate and the second substrate are oppositely arranged, the guest-host liquid crystal layer is arranged between the first substrate and the second substrate, and the 1/4 wavelength phase delay layer is arranged between the first substrate and the guest-host liquid crystal layer; the first driving structure layer and the light emitting unit are disposed between the first substrate and the 1/4 wavelength-phase retardation layer; the orthographic projection of the open area of the transmissive sub-pixel is located within the orthographic projection of the 1/4 wavelength phase retarder. The display panel provided by the embodiment has the advantages that the guest host liquid crystal layer and the 1/4 wavelength phase delay layer are arranged, and compared with a circular polarizer, the light emitting rate can be greatly improved, the display brightness is enhanced, the power consumption is reduced, and the service life of the display panel is prolonged.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and drawings.

Other aspects will be apparent upon reading and understanding the attached drawings and detailed description.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosed embodiments and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

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

FIG. 2 is a schematic diagram illustrating a dark state display principle of the display panel according to an exemplary embodiment;

FIG. 3 is a schematic diagram illustrating a bright state display principle of the display panel according to an exemplary embodiment;

FIG. 4 is a schematic diagram of a high brightness display principle of a display panel according to an exemplary embodiment;

FIG. 5 is a schematic diagram of a display panel provided in an exemplary embodiment;

FIG. 6 is a schematic diagram of a display panel provided in an exemplary embodiment (a reflective layer disposed on an organic light emitting layer near a first substrate side);

FIG. 7 is a schematic diagram of a display panel provided in an exemplary embodiment (a second driving structure layer is disposed on a first substrate);

FIG. 8 is a schematic diagram of a display panel provided in an exemplary embodiment (a second driving structure layer is disposed on a second substrate);

FIG. 9 is a schematic diagram illustrating a dark state display principle of the display panel shown in FIG. 5;

FIG. 10 is a schematic diagram of a reflection-mode bright-state display principle of the display panel shown in FIG. 5;

FIG. 11 is a schematic diagram of a transmission-mode bright-state display principle of the display panel shown in FIG. 5;

FIG. 12 is a schematic diagram of a high brightness display principle of the display panel shown in FIG. 5;

FIG. 13 is a schematic diagram of a display panel according to an exemplary embodiment (the surface of the reflective layer is rough);

FIG. 14 is a schematic diagram of a display panel (resonant cavity) provided in an exemplary embodiment;

FIG. 15 is a schematic diagram of a resonant cavity provided in an exemplary embodiment;

fig. 16 is a schematic diagram of a display panel (with a color film structure layer) according to an exemplary embodiment;

fig. 17 is a flowchart of a method for manufacturing a display panel according to an exemplary embodiment.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the case of conflict, the embodiments of the present disclosure and the features of the embodiments may be arbitrarily combined with each other.

The steps illustrated in the flow charts of the figures may be performed in a computer system such as a set of computer-executable instructions. Also, while a logical order is shown in the flow diagrams, in some cases, the steps shown or described may be performed in an order different than here.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

In the drawings, the size of each component, the thickness of layers, or regions may be exaggerated for clarity. Therefore, the embodiments of the present disclosure are not necessarily limited to the dimensions, and the shapes and sizes of the respective components in the drawings do not reflect a true scale. Further, the drawings schematically show ideal examples, and the embodiments of the present disclosure are not limited to the shapes or numerical values shown in the drawings.

The ordinal numbers such as "first", "second", "third", etc., in this disclosure are provided to avoid confusion among the constituent elements, and do not indicate any order, number, or importance.

In the present disclosure, for convenience, terms indicating orientation or positional relationship such as "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like are used to explain positional relationship of constituent elements with reference to the drawings, only for convenience of description and simplification of description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured in a specific orientation, and be operated, and thus, should not be construed as limiting the present disclosure. The positional relationship of the components is changed as appropriate in accordance with the direction in which each component is described. Therefore, the words described in the disclosure are not limited thereto, and may be replaced as appropriate.

In this disclosure, the terms "mounted," "connected," and "connected" are to be construed broadly unless otherwise specifically stated or limited. For example, it may be a fixed connection, or a removable connection, or an integral connection; can be a mechanical connection, or an electrical connection; either directly or indirectly through intervening components, or both may be interconnected. The specific meaning of the above terms in the present disclosure can be understood by those of ordinary skill in the art as appropriate.

In the present disclosure, a transistor refers to an element including at least three terminals of a gate electrode, a drain electrode, and a source electrode. The transistor has a channel region between a drain electrode (drain electrode terminal, drain region, or drain electrode) and a source electrode (source electrode terminal, source region, or source electrode), and current can flow through the drain electrode, the channel region, and the source electrode. In the present disclosure, the channel region refers to a region through which current mainly flows.

In the present disclosure, "parallel" means a state in which an angle formed by two straight lines is-10 ° or more and 10 ° or less, and therefore, includes a state in which the angle is-5 ° or more and 5 ° or less. The term "perpendicular" refers to a state in which the angle formed by two straight lines is 80 ° or more and 100 ° or less, and therefore includes a state in which the angle is 85 ° or more and 95 ° or less.

In the present disclosure, "film" and "layer" may be interchanged with one another. For example, the "conductive layer" may be sometimes replaced with a "conductive film". Similarly, the "insulating film" may be replaced with an "insulating layer".

Fig. 1 is a schematic diagram of a display panel according to an exemplary embodiment. As shown in fig. 1, the display panel provided in the present embodiment includes: at least one transmissive sub-pixel comprising a first driving structure layer 11 and a light emitting unit 20 arranged in sequence, the display panel comprising, in a direction perpendicular to a display surface of the display panel: a first substrate 10 and a second substrate 90 disposed opposite to each other, a guest-host liquid crystal layer 70 disposed between the first substrate 10 and the second substrate 90, and an 1/4 wavelength phase retardation layer 50 disposed between the first substrate 10 and the guest-host liquid crystal layer 70; the first driving structure layer 11 and the light emitting unit 20 are disposed between the first substrate 10 and the 1/4 wavelength phase retardation layer 50, and the first driving structure layer 11 is disposed on the side of the light emitting unit 20 close to the first substrate 10; the orthographic projection of the open area of the transmissive sub-pixel lies within the orthographic projection of the 1/4 wavelength phase retarder layer 50.

In an exemplary embodiment, the first and second substrates may be rigid substrates, such as glass substrates, or may be flexible substrates, such as Polyimide (PI) substrates.

In an exemplary embodiment, the guest-host liquid crystal layer 70 includes guest-host liquid crystal molecules, which refer to liquid crystal molecules filled with dichroic dye molecules, i.e., a mixture of liquid crystal and dichroic dye. The guest-host liquid crystal molecules have a guest-host effect, and are prepared by dissolving dichroic dyes having different absorption of visible light in the major axis direction and the minor axis direction as guests in an aligned liquid crystal host, wherein the dichroic dyes are aligned in the same direction as the liquid crystal molecules, and when the arrangement of the liquid crystal molecules as the host is changed under the action of an electric field, the arrangement direction of the dichroic dye molecules is changed accordingly, that is, the absorption of incident light by the dichroic dyes is also changed.

In an exemplary embodiment, the display panel may further include a first electrode layer 60 disposed between the 1/4 wavelength phase retarder layer 50 and the guest-host liquid crystal layer 70, a second electrode layer 80 disposed between the second substrate 90 and the guest-host liquid crystal layer 70, the first electrode layer 60 may be a pixel electrode layer, and the second electrode layer 80 may be a common electrode layer; alternatively, the second electrode layer 80 may be a pixel electrode layer, and the first electrode layer 60 may be a common electrode layer.

In another embodiment, the first electrode layer 60 may be disposed between the 1/4 wavelength phase retardation layer 50 and the light emitting cell 20.

In an exemplary embodiment, the first electrode layer 60 and the second electrode layer 80 may be transparent electrodes, such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or the like.

In an exemplary embodiment, the display panel may further include a first alignment film 110 disposed between the first substrate 10 and the guest-host liquid crystal layer 70 and a second alignment film 120 disposed between the second substrate 90 and the guest-host liquid crystal layer 70, and the first alignment film 110 and the second alignment film 120 may align liquid crystal molecules in the guest-host liquid crystal layer 70, and when no voltage is applied, the liquid crystal molecules may be arranged in a certain direction, so as to prevent the liquid crystal molecules from being scattered, causing scattering of light, and forming a light leakage phenomenon.

In an exemplary embodiment, the first and

second alignment films

110 and 120 may be prepared using Polyimide (PI).

In an exemplary embodiment, the 1/4 wave phase retarder 50 may be prepared using one or more materials including, but not limited to, acrylate, cyclohexanone, photo polymerization initiator, liquid crystal, etc., and may be prepared using a coating (Coater) apparatus, an Ultraviolet (UV) apparatus, a thermal curing apparatus, etc.

In an exemplary embodiment, the initial orientation of the guest-host liquid crystal molecules of the guest-host liquid crystal layer 70 may be horizontally aligned (parallel to the first substrate 10), or may be vertically aligned (perpendicular to the first substrate 10), wherein the display panel is in a long black mode when the guest-host liquid crystal molecules of the guest-host liquid crystal layer 70 are horizontally aligned, and in a normally white mode when the guest-host liquid crystal molecules are vertically aligned.

Taking the long black mode as an example, the display panel realizes the dark state principle as follows:

as shown in fig. 2, the light emitting unit 20 does not emit light, and the ambient light from the outside changes into the first linearly polarized light after passing through the guest host liquid crystal layer 70, the polarization direction of the first linearly polarized light (the direction perpendicular to the first substrate 10, also referred to as the Y direction) is perpendicular to the optical axis direction of the guest host liquid crystal, the first linearly polarized light changes into the left circularly polarized light after passing through the 1/4 wavelength phase retardation layer 50, the left circularly polarized light is reflected back to change into the right circularly polarized light, the right circularly polarized light changes into the second linearly polarized light after passing through the 1/4 wavelength phase retardation layer 50, the polarization direction of the second linearly polarized light (the direction parallel to the first substrate 10, also referred to as the X direction) is parallel to the optical axis direction of the guest host liquid crystal, the second linearly polarized light is absorbed by the guest host liquid crystal layer 70.

As shown in fig. 3, the display panel realizes the bright state principle as follows:

when a voltage is applied to the light emitting unit 20, the light emitting unit 20 emits light, the light emitted by the light emitting unit 20 is still natural light after passing through the 1/4 wavelength phase retardation layer 50, and is changed into linearly polarized light in the Y direction after passing through the guest host liquid crystal layer 70, so that the light is emitted, and the display panel is in a bright state.

In addition, the display panel provided by the embodiment can realize high-brightness display.

As shown in fig. 4, a voltage is applied across the guest-host liquid crystal layer 70, so that guest-host liquid crystal molecules of the guest-host liquid crystal layer 70 are vertically aligned, a voltage is applied to the light emitting unit 20, the light emitting unit 20 emits light, the light emitted by the light emitting unit 20 is still natural light after passing through the 1/4 wavelength phase retardation layer 50 and the guest-host liquid crystal layer 70, the guest-host liquid crystal transmittance in a vertical state can reach 70%, compared with a display panel using a polarizer, the polarizer transmittance is 42%, the transmittance of the present scheme is greatly improved, and high brightness display is achieved. The display panel provided by the embodiment can improve the light transmittance, save energy consumption and prolong the service life of the luminescent material of the luminescent unit.

In an exemplary embodiment, the first driving structure layer 11 may include a thin film transistor composed of an active layer, a gate electrode, a source electrode, and a drain electrode. The light emitting unit 20 may be an organic light emitting diode, and the light emitting unit 20 may include an anode, a pixel defining layer, an organic light emitting layer, and a cathode, which are sequentially disposed, the pixel defining layer defining an opening region of the transmissive sub-pixel. The organic light emitting layer emits light of corresponding color under the drive of the cathode and the anode, and the light can be white light, red light, blue light, green light or the like.

In an exemplary embodiment, the display panel may further include an encapsulation layer 30 disposed between the light emitting unit 20 and the 1/4 wavelength phase retardation layer 50, and the encapsulation layer 30 may include a first inorganic encapsulation layer, a second organic encapsulation layer, and a third inorganic encapsulation layer disposed in this order.

Fig. 5 is a schematic diagram of a display panel according to an exemplary embodiment. As shown in fig. 5, the display panel may include at least one reflective sub-pixel including a reflective layer 40 and at least one transmissive sub-pixel including a first driving structure layer 11 and a light emitting unit 20 sequentially disposed on a first substrate 10, and in a direction perpendicular to a display surface of the display panel, the display panel includes: a first substrate 10 and a second substrate 90 disposed opposite to each other, and a guest-host liquid crystal layer 70 disposed between the first substrate 10 and the second substrate 90, and may further include an 1/4 wavelength phase retardation layer 50 disposed between the first substrate 10 and the guest-host liquid crystal layer 70; the reflective layer 40 and the light emitting unit 20 are disposed between the first substrate 10 and the 1/4 wavelength phase retardation layer 50; on a plane parallel to the first substrate 10, an orthogonal projection of the open area of the transmissive sub-pixel is at least partially outside an orthogonal projection of the reflective layer 40, and an orthogonal projection of the reflective layer 20 and the open area of the transmissive sub-pixel is within an orthogonal projection of the 1/4 wavelength phase retarder 50.

The display substrate provided by the embodiment can achieve better display effect indoors and outdoors by arranging the reflective sub-pixels and the transmissive sub-pixels, has high luminous efficiency during transmissive display, can display the reflective sub-pixels and the transmissive sub-pixels simultaneously, and has high aperture ratio.

In this embodiment, the guest-host liquid crystal layer 70 and the 1/4 wavelength phase retardation layer 50 are used to realize the functions of the polarizer and the common liquid crystal, and the transmittances of the guest-host liquid crystal layer 70 and the 1/4 wavelength phase retardation layer 50 are greater than those of the polarizer and the common liquid crystal, so that the light transmittance is increased, the display brightness is improved, and the display power consumption is reduced.

In this embodiment, the direction perpendicular to the display surface of the display panel is the same as the direction perpendicular to the first substrate 10.

In an exemplary embodiment, an orthogonal projection of the opening region of the transmissive sub-pixel may be located outside an orthogonal projection of the reflective layer 40. I.e. the transmissive sub-pixels are not blocked by the reflective layer 40.

In an exemplary embodiment, the reflective layer 40 may be a metal, such as silver (Ag), aluminum (Al), an ITO/silver/ITO stack, or a silver/titanium (Ti) stack, and the like, which is not limited by the embodiment of the disclosure.

In an exemplary embodiment, the thickness of the reflective layer 40 may be 90 nanometers (nm) to 110 nm.

In an exemplary embodiment, as shown in fig. 5, the reflective layer 40 may be disposed on a side of the light emitting unit 20 away from the first substrate 10.

In an exemplary embodiment, as shown in fig. 6, the light emitting unit 20 may include an anode 21, an organic light emitting layer 22, and a cathode 23 sequentially disposed, and the reflective layer 40 may be disposed on a side of the organic light emitting layer 22 adjacent to the first substrate 10. The scheme provided by the embodiment can avoid the influence of the preparation process of the reflecting layer 40 on the organic light-emitting layer 22. For example, when the reflective layer 40 is manufactured using a high temperature process, the reflective layer 40 is manufactured before the organic light emitting layer 22 is manufactured, thereby preventing the organic light emitting layer 22 from being affected. The position of the reflective layer 40 shown in fig. 6 is merely an example, and the reflective layer 40 may be disposed in the same layer as the film layer of the first driving structure layer 11, for example, in the same layer as the source electrode and the drain electrode of the first driving structure layer 11, and so on.

In an exemplary embodiment, the display panel includes a scattering layer 100, and the scattering layer 100 may be a scattering film that can collect external ambient light with a large angle into light with a small angle, such as light that can be changed to be perpendicular to a display surface, and can collect light. The scattering layer 100 can improve reflectivity, improve Contrast Ratio (CR) and viewing angle of the display panel, and enhance display effect.

In an exemplary embodiment, the scattering layer 100 may be made using a polymer material.

In an exemplary embodiment, the thickness of the scattering layer 100 may be in the order of micrometers, such as tens of micrometers.

In an exemplary embodiment, the display panel may include a plurality of pixels, and the pixels may include at least one reflective sub-pixel and at least one transmissive sub-pixel, for example, one pixel may include 3 reflective sub-pixels and 3 transmissive sub-pixels, the 3 reflective sub-pixels may be a red reflective sub-pixel, a green reflective sub-pixel, and a blue reflective sub-pixel, and the 3 transmissive sub-pixels may be a red transmissive sub-pixel, a green transmissive sub-pixel, and a blue transmissive sub-pixel. The 3 reflective sub-pixels and the 3 transmissive sub-pixels may be alternately arranged in the pixel region, or the 3 reflective sub-pixels may be arranged in one row, and the 3 transmissive sub-pixels may be arranged in an adjacent row, or the 3 reflective sub-pixels may be arranged in one column, and the 3 transmissive sub-pixels may be arranged in an adjacent column, and so on, which are not limited in this disclosure.

In an exemplary embodiment, as shown in fig. 7, the display panel may further include an encapsulation layer 30 disposed between the light emitting unit 20 and the 1/4 wavelength phase retardation layer 50, and a second driving structure layer 12 disposed between the encapsulation layer 30 and the 1/4 wavelength phase retardation layer 50. The second driving structure layer 12 includes a thin film transistor for controlling the reflective sub-pixel. The second driving structure layer 12 may be prepared through a low temperature process.

In an exemplary embodiment, as shown in fig. 8, the second driving structure layer 12 may be disposed between the guest-host liquid crystal layer 70 and the second substrate 90. The display panel may further include a first electrode layer 60 disposed at a side of the guest-host liquid crystal layer 70 adjacent to the first substrate 10 and a second electrode layer 80 disposed at a side of the guest-host liquid crystal layer 70 adjacent to the second substrate 90, and one of the first electrode layer 60 and the second electrode layer 80 may be a pixel electrode layer and the other may be a common electrode layer. The second driving structure layer 12 may be disposed between the second electrode layer 80 and the second substrate 90. The amount of light emitted from the guest-host liquid crystal layer 70 may be controlled to adjust the display luminance of different regions of the display panel by adjusting the angle of deflection of guest-host liquid crystal molecules in the guest-host liquid crystal layer by adjusting the voltage between the first electrode layer 60 and the second electrode layer 80.

In an exemplary embodiment, the guest-host liquid crystal molecules of the guest-host liquid crystal layer 70 may be horizontally aligned (parallel to the first substrate 10), or may be vertically aligned (perpendicular to the first substrate 10). The display panel is in a long black mode when the guest-host liquid crystal molecules of the guest-host liquid crystal layer 70 are horizontally arranged, and in a normally white mode when the guest-host liquid crystal molecules are vertically arranged.

The display panel provided by the embodiment can realize multiple display modes, a reflection mode, a transmission mode and high-brightness display, can be switched among different display modes, and can be automatically switched according to the environment or manually switched by a user. The display principle of the display panel is described below by taking the long black mode as an example. The long white pattern is similar and will not be described again.

The display panel realizes the principle of a reflection mode dark state as follows:

as shown in fig. 9, the light emitting unit 20 does not emit light, and the ambient light from the outside becomes the first linearly polarized light after passing through the guest host liquid crystal layer 70, the polarization direction of the first linearly polarized light (the direction perpendicular to the first substrate 10, also referred to as the Y direction) is perpendicular to the optical axis direction of the guest host liquid crystal, the first linearly polarized light becomes the left circularly polarized light after passing through the 1/4 wavelength phase retardation layer 50, the left circularly polarized light is reflected by the reflective layer 40 and the electrodes of the light emitting unit 20, and becomes the right circularly polarized light, the right circularly polarized light becomes the second linearly polarized light after passing through the 1/4 wavelength phase retardation layer 50, the polarization direction of the second linearly polarized light (the direction parallel to the first substrate 10, also referred to as the X direction) is parallel to the optical axis direction of the guest host liquid crystal, and the second linearly polarized light is absorbed by the guest host liquid crystal layer 70.

As shown in fig. 10, the bright state principle of the display panel implementing the reflective mode is as follows:

the light emitting unit 20 does not emit light, a voltage is applied across the guest-host liquid crystal layer 70 to make the guest-host liquid crystal molecules of the guest-host liquid crystal layer 70 vertically aligned, ambient light from the outside enters the display panel, remains natural light after passing through the 1/4 wavelength phase retardation layer 50 and the guest-host liquid crystal layer 70, remains natural light after being reflected by the reflective layer 40, passes through the 1/4 wavelength phase retardation layer 50 and the guest-host liquid crystal layer 70, and light is emitted from the display surface to make the display panel appear bright.

The principle of the display panel for realizing the bright state of the transmission mode is as follows:

as shown in fig. 11, when a voltage is applied to the light emitting unit 20, the light emitting unit 20 emits light, and the light emitted from the light emitting unit 20 is still natural light after passing through the 1/4 wavelength retardation layer 50, and is changed into linearly polarized light in the Y direction after passing through the guest host liquid crystal layer 70, so as to be emitted, and the display panel is in a bright state.

The dark state of the transmissive mode is the same as the dark state of the reflective mode, and will not be described again.

The principle of the display panel for realizing high-brightness display is as follows:

as shown in fig. 12, a voltage is applied across the guest-host liquid crystal layer 70 to vertically align guest-host liquid crystal molecules of the guest-host liquid crystal layer 70, a voltage is applied to the light emitting unit 20, the light emitting unit 20 emits light, the light emitted from the light emitting unit 20 is still natural after passing through the 1/4 wavelength phase retardation layer 50 and the guest-host liquid crystal layer 70, the guest-host liquid crystal transmittance in a vertical state can reach 70%, and is greatly improved compared with the transmittance of the polarizer 42%, thereby implementing high brightness display. In addition, the external ambient light still remains natural light after passing through the guest-host liquid crystal layer 70 and the 1/4 wavelength phase retardation layer 50 in the vertical direction, and still remains natural light after passing through the 1/4 wavelength phase retardation layer 50 and the guest-host liquid crystal layer 70 after being reflected by the reflection layer 40, and is emitted from the display surface, so that the light emitting efficiency is improved, that is, not only the light transmittance of the light emitting unit itself is improved, but also the display brightness can be enhanced by using the external ambient light. The display panel provided by the embodiment can improve the light transmittance, save energy consumption and prolong the service life of the luminescent material of the luminescent unit.

In an exemplary embodiment, as shown in fig. 13, at least a portion of a surface of the reflective layer 40 on a side close to the second substrate 90 is a rough surface, and the rough surface is configured to emit light incident on the rough surface in a form of scattered light. In the scheme provided by this embodiment, the surface of the reflective layer 40 is rough, so that when a bright state is displayed, incident light is scattered, and theoretically, scattered light exists in all directions, so that a display screen can be seen by human eyes no matter which direction is seen, and therefore, the scattering layer 100 is not required, so that the preparation process can be simplified, and the cost can be reduced. The surface of the reflective layer 40 adjacent to the second substrate 90 in the embodiment shown in fig. 6 to 8 may be at least partially rough.

In an exemplary embodiment, the reflective layer 40 may be prepared by a bump (bump) process.

In an exemplary embodiment, the surface of the reflective layer 40 adjacent to the second substrate 90 may be a rough surface.

In the display panel provided by the above embodiments, the light emitting unit 20 may emit white light, or may emit color light, that is, black-and-white reflective display and black-and-white transmissive display may be implemented, or black-and-white reflective display and color transmissive display may be implemented.

Fig. 14 is a schematic diagram of a display panel according to an exemplary embodiment. As shown in fig. 14, the display panel provided in this embodiment further includes, on the basis of the embodiment shown in fig. 5, a transparent insulating layer 41 and a transflective layer 42 sequentially disposed on a side of the reflective layer 40 away from the first substrate 10, where the reflective layer 40, the transparent insulating layer 41 and the transflective layer 42 form a resonant cavity, and the resonant cavity is configured to emit light of a color corresponding to the reflective sub-pixel after multiple reflections of incident light. The resonant cavity can enhance the reflection of certain color light and reduce the reflection of other color light, so that the emergent light is enhanced color light. In the scheme provided by this embodiment, the resonant cavity is arranged, so that the reflective sub-pixel emits light of a corresponding color, and color reflective display can be realized. In addition, the reflectivity of the resonant cavity is higher than that of the reflecting layer, so that the light extraction rate can be improved, and the display brightness can be enhanced.

In an exemplary embodiment, the reflective sub-pixel may comprise a red reflective sub-pixel, a green reflective sub-pixel and a blue reflective sub-pixel, and accordingly the cavity of the red reflective sub-pixel emits red light, the cavity of the green reflective sub-pixel emits green light and the cavity of the blue reflective sub-pixel emits blue light.

In an exemplary embodiment, the thicknesses of the reflective layers 40 of the reflective sub-pixels of different colors may be the same in a direction perpendicular to the first substrate 10. But is not limited thereto, the thickness of the reflective layer 40 may be different. The same thickness can simplify the preparation process.

In an exemplary embodiment, the thickness of the transflective layer 42 may be 90nm to 110 nm.

In an exemplary embodiment, the thicknesses of the transflective layers 42 of the reflective sub-pixels of different colors may be the same in a direction perpendicular to the first substrate 10. But is not limited thereto, the thickness of the transflective layer 42 may be different. The preparation process is simple and convenient when the thicknesses are the same.

In an exemplary embodiment, the thickness of the transflective layer 42 may be 5nm to 15 nm.

In an exemplary embodiment, the thicknesses of the transparent insulating layers 41 of the reflective sub-pixels of different colors may be different in a direction perpendicular to the first substrate 10. As shown in fig. 15, there are three colors of reflective sub-pixels, which are respectively referred to as a first reflective sub-pixel, a second reflective sub-pixel and a third reflective sub-pixel, wherein the first reflective sub-pixel includes a first reflective layer 401, a first transparent insulating layer 411 and a first transflective layer 421, the second reflective sub-pixel includes a second reflective layer 402, a second transparent insulating layer 412 and a second transflective layer 422, the third reflective sub-pixel includes a third reflective layer 403, a third transparent insulating layer 413 and a third transflective layer 423, and a thickness H1 of the first transparent insulating layer 411, a thickness H2 of the second transparent insulating layer 412 and a thickness H3 of the third transparent insulating layer 413 are different.

In an exemplary embodiment, the thicknesses of the transparent insulating layers 41 of the reflective sub-pixels of different colors may be the same in a direction perpendicular to the first substrate 10, and at this time, the transparent insulating layers 41 may be made of different materials.

In an exemplary embodiment, the reflective layers 40 of the reflective sub-pixels of different colors may be made using the same material. But is not limited thereto, and may be prepared using different materials. The reflective layer 40 may be prepared using silver, aluminum, an ITO/silver/ITO stack, or a silver/titanium (Ti) stack, or the like.

In an exemplary embodiment, the transparent insulating layers 41 of the reflective sub-pixels of different colors may be made of the same material, but are not limited thereto, and may be made of different materials. For example, silicon dioxide (SiO) may be used₂) Silicon nitride (SiN)_X) And preparing insulating transparent materials such as silicon oxynitride.

In an exemplary embodiment, the transflective layers 42 of the reflective subpixels of different colors may be made of the same material. But is not limited thereto, and may be prepared using different materials. The transflective layer 42 may be made of metal having reflectivity and certain transmittance, such as metal tungsten, titanium, or the like.

In an exemplary embodiment, the reflective layers 40 of the reflective sub-pixels in the same pixel may be independent of each other or integral.

In an exemplary embodiment, the transparent insulating layer 41 may use silicon dioxide (SiO)₂) The transflective layer 42 may be made of metal tungsten, the reflective sub-pixel includes a red reflective sub-pixel, a green reflective sub-pixel, and a blue reflective sub-pixel, the thickness of the transparent insulating layer 41 of the green reflective sub-pixel may be 340 ± 20nm, the thickness of the transparent insulating layer 41 of the blue reflective sub-pixel may be 305 ± 20nm, and the thickness of the transparent insulating layer 41 of the red reflective sub-pixel may be 200 ± 20 nm.

In another exemplary embodiment, theSilicon dioxide (SiO) can be used for the transparent insulating layer 41₂) The transflective layer 42 may be made of titanium metal, the reflective sub-pixel includes a red reflective sub-pixel, a green reflective sub-pixel, and a blue reflective sub-pixel, the thickness of the transparent insulating layer 41 of the green reflective sub-pixel may be 160 ± 20nm, the thickness of the transparent insulating layer 41 of the blue reflective sub-pixel may be 130 ± 20nm, and the thickness of the transparent insulating layer 41 of the red reflective sub-pixel may be 190 ± 20 nm.

In an exemplary embodiment, the display panel may further include a planarization layer 43 on a side of the transflective layer 42 away from the first substrate 10. Because the resonant cavities have different lengths and different thicknesses in different regions, the surface of the display panel is uneven after the resonant cavities are formed, and therefore, the planarization layer 43 can be prepared to enable the surface to be flat, and the subsequent film layer can be conveniently manufactured.

The display principle of the display panel capable of implementing color reflective display provided by this embodiment is similar to that of the aforementioned black-and-white display, and is not described again.

In the display panel provided by this embodiment, the light emitting unit may emit white light, or may emit colored light, that is, color reflective display and black-and-white transmissive display may be implemented, or color reflective display and color transmissive display may be implemented.

In addition to the color display by the resonant cavity, in another embodiment, the color display can be realized by disposing a color filter structure layer. Fig. 16 is a schematic diagram of a display panel according to an exemplary embodiment. As shown in fig. 16, the display panel provided in this embodiment may further include, on the basis of the display panel shown in fig. 5: a color filter structure layer 130 disposed between the second substrate 90 and the guest-host liquid crystal layer 70, where the color filter structure layer 130 may include a plurality of color filter units 131 corresponding to the reflective sub-pixels one to one. The color filter 131 may filter light and emit light of a single color, such as red light, green light, blue light, etc., thereby implementing a color display.

In an exemplary embodiment, the color film structure layer 130 may further include color filter units 131 corresponding to the transmissive sub-pixels one to one. For example, when the light emitting unit of the transmissive sub-pixel emits white light, a corresponding color filter unit may be provided to realize transmissive color display. When the light emitting unit of the transmissive sub-pixel emits color light, the region corresponding to the transmissive sub-pixel may not be provided with the color filter unit. At this time, the color filter structure layer may be patterned, so that the opening region of the transmissive sub-pixel is located outside the orthographic projection of the color filter structure layer 130 on a plane parallel to the first substrate 10.

In an exemplary embodiment, a black matrix 132 may be disposed between the color filter units 131 to prevent color mixing between adjacent sub-pixels.

In an exemplary embodiment, the color filter unit 131 may be provided only for the reflective sub-pixel, and when the light emitting unit of the transmissive sub-pixel emits white light, color reflective display and black-and-white transmissive display may be implemented.

The color film structure layer 130 may be disposed in the foregoing embodiments to realize color display, for example, the display panel may be disposed with a resonant cavity and the color film structure layer 130, and the color film structure layer 130 filters light emitted from the resonant cavity, so as to improve light purity and reduce color mixture.

The embodiment of the disclosure also provides a display device, which comprises the display panel of the foregoing embodiment. The display device may be: any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like.

Fig. 17 is a flowchart of a method for manufacturing a display panel according to an embodiment of the disclosure. As shown in fig. 17, an embodiment of the present disclosure provides a method for manufacturing a display panel, where the display panel includes at least one transmissive sub-pixel, the method including:

step 1701, sequentially forming a first driving structure layer and a light emitting unit of the transmissive sub-pixel on a first substrate;

step 1702, forming an 1/4 wavelength phase retardation layer on a side of the light emitting unit away from the first substrate; the orthographic projection of the opening region of the transmissive sub-pixel is positioned in the orthographic projection of the 1/4 wavelength phase retardation layer;

and 1703, forming a guest-host liquid crystal layer on one side of the 1/4 wavelength phase retardation layer far away from the first substrate, or forming a guest-host liquid crystal layer on the second substrate, and forming the display panel by facing the first substrate and the second substrate.

In an exemplary embodiment, the display panel further includes at least one reflective sub-pixel, and the preparation method may further include:

forming a reflective layer between the first substrate and the 1/4 wavelength-phase retardation layer; an orthographic projection of the open area of the transmissive sub-pixel on a plane parallel to the first substrate is at least partially outside an orthographic projection of the reflective layer, which is within an orthographic projection of the 1/4 wavelength phase retarder layer.

Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A display panel, comprising: at least one transmissive sub-pixel comprising a first driving structure layer and a light emitting unit, the display panel comprising, in a direction perpendicular to a display surface of the display panel: a first substrate and a second substrate disposed opposite each other, a guest-host liquid crystal layer disposed between the first substrate and the second substrate, and an 1/4 wavelength phase retardation layer disposed between the first substrate and the guest-host liquid crystal layer; the first driving structure layer and the light emitting unit are disposed between the first substrate and the 1/4 wavelength-phase retardation layer; the orthographic projection of the open area of the transmissive sub-pixel is located within the orthographic projection of the 1/4 wavelength phase retarder.

2. The display panel according to claim 1, characterized in that the display panel further comprises: at least one reflective sub-pixel comprising a reflective layer disposed between the first substrate and the 1/4 wavelength-phase retardation layer; an orthographic projection of the open area of the transmissive sub-pixel on a plane parallel to the first substrate is at least partially outside an orthographic projection of the reflective layer, which is within an orthographic projection of the 1/4 wavelength phase retarder layer.

3. The display panel according to claim 2, wherein the reflective layer is provided on a side of the light emitting unit away from the first substrate; or, the light-emitting unit comprises an organic light-emitting layer, and the reflecting layer is arranged on one side of the organic light-emitting layer close to the first substrate.

4. The display panel of claim 2, wherein the reflective sub-pixel further comprises: the transparent insulating layer and the semi-transparent and semi-reflective layer are sequentially arranged on one side, away from the first substrate, of the reflective layer; and the reflecting layer, the transparent insulating layer and the semi-transmitting and semi-reflecting layer form a resonant cavity, and the resonant cavity is set to emit light with the color corresponding to the reflective sub-pixel after the incident light is reflected for multiple times.

5. The display panel according to claim 4, wherein the transparent insulating layers of the reflective sub-pixels of different colors have different thicknesses in a direction perpendicular to the first substrate.

6. The display panel according to any one of claims 1 to 5, characterized by further comprising: and the scattering layer is arranged on one side of the second substrate far away from the first substrate.

7. The display panel according to any one of claims 2 to 5, wherein a surface of the reflective layer on a side close to the second substrate is at least partially roughened, and the roughened surface is configured to emit light incident on the roughened surface in the form of scattered light.

8. The display panel according to any one of claims 2 to 5, characterized by further comprising: and the color film structure layer is arranged between the second substrate and the guest-host liquid crystal layer and comprises a plurality of color filtering units which correspond to the reflective sub-pixels one to one.

9. The display panel according to claim 8, wherein the color film structure layer further comprises: and the color filter units correspond to the transmission type sub-pixels one by one.

10. The display panel according to any one of claims 2 to 5, characterized by further comprising: an encapsulation layer disposed between the light emitting cells and the 1/4 wavelength-phase retardation layer; a first electrode layer disposed between the first substrate and the guest-host liquid crystal layer, a second electrode layer disposed between the second substrate and the guest-host liquid crystal layer;

11. A display device comprising the display panel according to any one of claims 1 to 10.

12. A method of fabricating a display panel, the display panel comprising at least one transmissive sub-pixel, the method comprising: