Light-emitting structure, light-emitting unit, display device, and electronic device

Abstract

A light-emitting structure, a light-emitting unit, a display device, and an electronic device. The light-emitting structure includes: a light-emitting layer for emitting light; a first reflective surface located on one side of the light-emitting layer for reflecting light incident on the first reflective surface; and a reflective polarization layer located on the other side of the light-emitting layer, configured to reflect incident light having a first polarization direction and transmit incident light having a second polarization direction. Since the light-emitting structure includes the reflective polarization layer, the light-emitting structure can generate light having a certain polarization orientation, and has a high integration degree, which is conducive to the miniaturization and high integration of a linearly polarized light source. Moreover, the light-emitting structure combined with an isolation structure can suppress the transmission of ambient light while increasing the light-emitting intensity, thereby achieving the purpose of both suppressing ambient light and increasing the light-emitting intensity, which is conducive to improving the light-emitting efficiency and reducing the energy consumption.

Description

Technical Field

[0001] The present invention relates to the field of light-emitting devices, and particularly to a light-emitting structure, a light-emitting unit, a display device, and an electronic device. Background Art

[0002] With the development of display technology, various display devices are widely used in various electronic devices. Moreover, with the development of various electronic component technologies, the power consumption of display devices accounts for an increasingly high proportion in various electronic devices.

[0003] On the other hand, display devices are often in the light fields of various far-field lights (such as ambient light). The existence of far-field light will have an adverse impact on the display effect. Therefore, display devices need to perform special processing to suppress the reflection of ambient light in the display devices.

[0004] Existing display devices use the polarization characteristics of light to suppress ambient light. However, existing light-emitting structures that generate linearly polarized light often have problems such as large device size and low integration. Moreover, in the corresponding light-emitting units, while suppressing the influence of ambient light, it is also easy to cause problems such as low light-emitting efficiency and high energy consumption. Summary of the Invention

[0005] Problems to be Solved by the Invention: The low integration of the light-emitting structure that generates linearly polarized light, and in the light-emitting unit, while suppressing the influence of ambient light, how to improve the light-emitting efficiency and reduce the energy consumption.

[0006] To solve the above problems, the present invention provides a light-emitting structure, including: a light-emitting layer for emitting light; a first reflection surface located on one side of the light-emitting layer for reflecting the light incident on the first reflection surface; a reflection polarization layer located on the other side of the light-emitting layer for reflecting the incident light with a first polarization direction and transmitting the incident light with a second polarization direction.

[0007] Optionally, it further includes: an electrode layer, and the surface of the electrode layer facing the light-emitting layer is the first reflection surface.

[0008] Optionally, the second polarization direction includes a polarization state orthogonal to the first polarization direction.

[0009] Optionally, the reflection polarization layer includes a reflection-type polarizing brightness enhancement film or a polarizer composed of a highly reflective metal grid, or a polarizer formed based on a photonic crystal with different optical bandgaps and passbands designed for different polarizations.

[0010] Optionally, it further includes: a deflection layer located between the reflective polarization layer and the light-emitting layer, and the deflection layer is adapted to change the polarization state of the light transmitted through the deflection layer compared to the polarization state of the light incident on the deflection layer.

[0011] Optionally, the deflection layer changing the polarization state of the light transmitted through the deflection layer includes: the deflection layer changing the energy distribution of the light transmitted through the deflection layer in each polarization direction.

[0012] Optionally, the deflection layer changing the polarization state of the light transmitted through the deflection layer includes: the deflection layer changing the polarization direction of the light transmitted through the deflection layer compared to the polarization direction of the light incident on the deflection layer, and / or generating a phase difference between different components of the light transmitted through the deflection layer.

[0013] Optionally, the deflection layer includes at least one of a half-wave plate, an electro-optic crystal layer, and a polarization anisotropic photonic crystal layer.

[0014] Optionally, the deflection layer is formed of a light-transmitting material with birefringence properties or a plasma.

[0015] Optionally, the material of the electrode layer is a high-reflectivity material.

[0016] Optionally, the light-emitting layer includes at least one of an organic light-emitting layer, a quantum dot light-emitting layer, an electroluminescent layer, a Micro-LED light-emitting layer, and a plasma light-emitting layer.

[0017] Optionally, it further includes: a second reflection surface disposed opposite to the first reflection surface, and the second reflection surface is adapted to reflect at least part of the light incident on the second reflection surface, so that the light emitted by the light-emitting layer can propagate back and forth between the first reflection surface and the second reflection surface.

[0018] Optionally, the surface of the reflective polarization layer facing the light-emitting layer is the second reflection surface.

[0019] In addition, the present invention further provides a light-emitting unit, including: the light-emitting structure of the present invention; an isolation structure located on the side of the reflective polarization layer away from the light-emitting layer, and the isolation structure is adapted to adjust the polarization direction of the transmitted light to isolate the ambient light reflected by the first reflection surface.

[0020] Optionally, the isolation structure includes: a quarter-wave plate and an absorption polarizer.

[0021] Optionally, the emitted light generated by the light-emitting structure is incident on the quarter-wave plate and the absorption polarizer in sequence, and the included angle between the polarization direction of the absorption polarizer and the optical axis direction of the quarter-wave plate is 45°.

[0022] Optionally, the light emitted from the light-emitting layer in the emitted light generated by the light-emitting structure forms elliptically polarized light after passing through the quarter-wave plate.

[0023] Optionally, the included angle between the major axis direction of the ellipse of the elliptically polarized light and the polarization direction of the absorption polarizer is less than 45°.

[0024] Optionally, the included angle between the polarization direction of the absorption polarizer and the optical axis direction of the quarter-wave plate is twice the included angle between the optical axis direction of the quarter-wave plate and the polarization direction of the light emitted from the light-emitting layer in the emitted light generated by the light-emitting structure.

[0025] Optionally, the polarization direction of the light emitted from the light-emitting layer in the emitted light generated by the light-emitting structure is not in the optical axis direction of the quarter-wave plate and not in the direction forming a 45-degree angle with the optical axis of the quarter-wave plate.

[0026] Optionally, the included angle between the polarization direction of the light emitted from the light-emitting layer in the emitted light generated by the light-emitting structure and the polarization direction of the absorption polarizer or the optical axis direction of the quarter-wave plate is 22.5°.

[0027] Correspondingly, the present invention further provides a display device, including: at least one display pixel, and the display pixel includes the light-emitting structure or the light-emitting unit of the present invention.

[0028] Optionally, it includes: a mobile terminal display screen, a computer display screen, a television display screen, an advertising display screen, a vehicle-mounted display screen, a control screen of an instrument or meter, or a flight control screen.

[0029] The present invention further provides an electronic device, including: the display device of the present invention.

[0030] Optionally, it includes a mobile terminal, a computer, a vehicle-mounted electronic device, a control device of an instrument or meter, an electronic advertising system, or a television.

[0031] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0032] In the technical solution of the present invention, the reflective polarizing layer can reflect incident light with a first polarization direction and transmit incident light with a second polarization direction; the light-emitting structure includes the reflective polarizing layer, so the light-emitting structure can generate light with a certain polarization orientation and has a high degree of integration, which is conducive to the miniaturization and high integration of linearly polarized light sources.

[0033] In an optional embodiment of the present invention, the surface of the electrode layer facing the light-emitting layer serves as the first reflective surface; the surface of the reflective polarizing layer facing the light-emitting layer serves as the second reflective surface. Using existing film structures to form the first and second reflective surfaces is simple and convenient, minimizing changes to the existing light-emitting structure design, effectively controlling process costs and ensuring yield.

[0034] In an optional solution of the present invention, the light-emitting structure further includes a deflection layer located between the first reflecting surface and the reflective polarizing layer. The deflection layer can change the polarization state of the transmitted light compared to the polarization state of the incident light. Therefore, the combination of the deflection layer and the reflective polarizing layer can enable as much light generated by the light-emitting layer as possible to be emitted from the light-emitting structure, thereby effectively improving the luminous efficiency and effectively reducing energy consumption.

[0035] In the technical solution of the present invention, the light-emitting structure in the light-emitting unit generates linearly polarized light based on the light emitted by the light-emitting layer; the isolation structure isolates ambient light by adjusting the polarization direction. By properly adjusting the polarization direction of the linearly polarized light generated by the light-emitting structure, it is possible to simultaneously suppress the transmission of ambient light while increasing the luminous intensity, thereby achieving the goal of both suppressing ambient light and increasing luminous intensity, which is beneficial for improving luminous efficiency and reducing energy consumption.

[0036] In an optional solution of the present invention, the isolation structure includes: a 1 / 4 wave plate and an absorption polarizer arranged in sequence along the light path of the light-emitting structure, forming a non-magnetic field (Faraday) optical isolator design, so that the incident ambient light cannot return to the original incident direction, thereby eliminating the reflection of the ambient light by the high-reflectivity electrode, so that the light emitted by the light-emitting structure can be used.

[0037] In an optional solution of the present invention, the angle between the polarization direction of the absorbing polarizer and the optical axis direction of the 1 / 4 wave plate is equal to twice the angle between the polarization direction of the absorbing polarizer and the polarization direction of the linearly polarized light generated by the light-emitting structure, which can better achieve the effect of suppressing the transmission of ambient light while improving the luminous intensity.

[0038] In an alternative embodiment of the present invention, the emitted light generated by the light-emitting structure is incident on the quarter-wave plate and the absorption polarizer in sequence. The polarization direction of the absorption polarizer forms an angle of 45° with the optical axis direction of the quarter-wave plate. The polarization direction of the light emitted from the light-emitting layer in the emitted light generated by the light-emitting structure is neither in the optical axis direction of the quarter-wave plate nor in the direction forming an angle of 45 degrees with the optical axis of the quarter-wave plate. As a result, the light emitted from the light-emitting layer in the emitted light generated by the light-emitting structure forms elliptically polarized light after passing through the quarter-wave plate. When the angle between the major axis direction of the elliptically polarized light and the polarization direction of the absorption polarizer is less than 45°, it is possible to better suppress the transmission of ambient light while significantly increasing the luminous intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic cross-sectional structure diagram of a light-emitting unit;

[0040] Figure 2 is Figure 1 a schematic optical path structure diagram of the light-emitting unit for suppressing the influence of ambient light;

[0041] Figure 3 is Figure 1 a schematic optical path structure diagram of the light-emitting unit for emitting light;

[0042] Figure 4 is a schematic cross-sectional structure diagram of an embodiment of the light-emitting unit of the present invention;

[0043] Figure 5 is Figure 4 a schematic optical path structure diagram of the light-emitting unit of the embodiment of the present invention for emitting light;

[0044] Figure 6 is Figure 4 a schematic optical path structure diagram of the light-emitting unit of the embodiment of the present invention for suppressing the influence of ambient light;

[0045] Figure 7 is a relationship diagram between the light output intensity and the light output angle of light-emitting units with different structures. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] As can be seen from the background art, the light-emitting structures in the prior art have the problem of low integration, and the light-emitting units have the problem that it is difficult to simultaneously take into account suppressing the environmental impact and improving the luminous efficiency. Now, the reasons for the above problems are analyzed in combination with the specific structures of the light-emitting structure and the light-emitting unit.

[0047] Referring to Figure 1 , a schematic cross-sectional structure diagram of a light-emitting unit is shown.

[0048] The light-emitting unit includes: a light-emitting structure 11 and an isolation structure 12. Among them, the light-emitting structure 11 includes: a light-emitting layer 11b for emitting light and an electrode layer 11a located on one side of the light-emitting layer 11b. Among them, the light-emitting layer 11b can generate light. Figure 1 In the shown light-emitting unit, the light-emitting layer 11b is an organic light-emitting layer, that is, an OLED layer. However, the light-emitting layer can also be other light-emitting layers, such as a quantum dot light-emitting layer, an electroluminescent layer, a Micro-LED light-emitting layer (for example, a Micro-LED light-emitting layer using III-V compound semiconductor materials as the light-emitting medium), or a plasma light-emitting layer.

[0049] The electrode layer 11a is electrically connected to the light-emitting layer 11b to realize the connection between the light-emitting layer 11b and an external circuit. Generally, the material of the electrode layer 11a is metal, so the electrode layer 11a has a high reflectivity and can reflect light, that is, the surface of the electrode layer 11a facing the light-emitting layer 11b is a first reflecting surface 11c, the first reflecting surface 11c is located on one side of the light-emitting layer 11b, and the first reflecting surface 11c is suitable for reflecting the light incident on the first reflecting surface 11c.

[0050] Since the electrode layer 11a can reflect light, when ambient light 10 is projected onto the surface of the light-emitting unit, the electrode layer 11a will reflect the ambient light and affect the light-emitting effect of the light-emitting unit. The isolation structure 12 is suitable for blocking the reflected ambient light to avoid its influence on the light-emitting effect of the light-emitting unit.

[0051] The isolation structure 12 is located on the other side of the light-emitting layer 11b, that is, the light-emitting layer 11b is located between the electrode layer 11a and the isolation structure 12. In some embodiments, the isolation structure 12 includes a quarter-wave plate 12a and an absorption polarizer 12b, and the included angle between the optical axis direction of the quarter-wave plate 12a and the polarization direction of the absorption polarizer 12b is 45°. In some embodiments, the quarter-wave plate 12a is located between the light-emitting layer 11b and the absorption polarizer 12b.

[0052] Combined with reference Figure 2 shows Figure 1 a schematic diagram of the optical path structure for the shown light-emitting unit to suppress the influence of ambient light.

[0053] Ambient light 10 is generally natural light and includes all possible polarization states perpendicular to the propagation direction of the ambient light 10; after the ambient light 10 is projected onto the absorption polarizer 12b, the light with the polarization direction parallel to the polarization direction of the absorption polarizer passes through the absorption polarizer to form incident ambient light 10a.

[0054] Since the included angle between the optical axis direction of the quarter-wave plate 12a and the polarization direction of the absorption polarizer 12b is 45°, the incident ambient light 10a forms circularly polarized ambient light 10b after passing through the quarter-wave plate 12a, and the circularly polarized ambient light is circularly polarized light.

[0055] After that, the circularly polarized ambient light 10b passes through the light-emitting layer 11b and is projected onto the electrode layer 11a. After being reflected by the electrode layer 11a, it passes through the light-emitting layer 11b again until it is projected onto the quarter-wave plate 12a again. Passing through the light-emitting layer 11b and being reflected by the electrode layer 11a will not change the polarization state of the circularly polarized ambient light 10b. Therefore, when it is projected onto the quarter-wave plate 12a again, the circularly polarized ambient light 10b remains circularly polarized light.

[0056] The circularly polarized ambient light 10b passes through the quarter-wave plate 12a again to form the reflected ambient light 10c. From the incident ambient light 10a to the reflected ambient light 10c, the light passes through the quarter-wave plate twice. For the reflected ambient light 10c relative to the incident ambient light 10a, a phase difference of 1 / 2 wavelength is generated between the two components. Therefore, the polarization state of the reflected ambient light 10c is restored to linearly polarized light, and the polarization direction of the reflected ambient light 10c is rotated by 90° relative to the incident ambient light 10a. That is to say, the polarization direction of the reflected ambient light 10c is orthogonal to the polarization direction of the incident ambient light 10a; therefore, the polarization direction of the reflected ambient light 10c is orthogonal to the polarization direction of the absorption polarizer 12b; so, when the reflected ambient light 10c passes through the absorption polarizer 12b, an extinction phenomenon will occur, thus achieving the purpose of suppressing the ambient light reflected by the electrode layer 11a.

[0057] It can be seen that the isolation structure 12 realizes ambient light suppression based on the polarization characteristics of light. Generally speaking, the light generated by the light-emitting layer 11b is natural light, that is, it includes all possible polarization states perpendicular to the propagation direction of the generated light. That is to say, the light-emitting structure 11 can only generate natural light and cannot generate linearly polarized light. In order to form linearly polarized light, a polarizer often needs to be provided outside the light-emitting structure 11, which easily leads to problems such as large device size and low integration of the light-emitting structure.

[0058] Combined with reference Figure 3 shows Figure 1 the optical path structure diagram of the light emission of the shown light-emitting unit.

[0059] The light generated by the light-emitting layer 11b can propagate to both sides of the light-emitting layer 11b. One side directly faces the isolation structure 12 (as Figure 1 shown), along the light-emitting unit 11 (as Figure 1The light emission optical path propagation shown (as Figure 3 shown by arrow 20a in), on the other side, is directed towards the electrode layer 11a and away from the light emission optical path of the light emitting unit 11. However, since the electrode layer 11a has a high reflectivity, the light rays directed towards the electrode layer 11a will be reflected by the electrode layer 11a and also propagate along the light emission optical path of the light emitting unit (as Figure 3 shown by arrow 20b in).

[0060] Although all the light rays generated by the light emitting layer 11b can propagate along the light emission optical path of the light emitting unit 11, since the ambient light optical path direction is opposite to the light emission optical path direction of the light emitting unit 11, the isolation structure including the quarter-wave plate 12a and the absorption polarizer 12b is located downstream of the light emission optical path of the light emitting unit 11. Therefore, the light rays generated by the light emitting layer 11b need to sequentially transmit through the quarter-wave plate 12a and the absorption polarizer 12b to achieve emission.

[0061] As Figure 3 shown, the natural light generated by the light emitting layer 11b transmits through the quarter-wave plate 12a, which only deflects the polarization direction of all the transmitted light rays and cannot change the polarization state of the light rays. Therefore, the light rays generated by the light emitting layer 13 are still natural light after transmitting through the quarter-wave plate 12a.

[0062] When light rays with a polarization state of natural light transmit through the absorption polarizer 12b, only part of the light rays with a polarization direction parallel to the polarization direction of the absorption polarizer 12b can transmit through to achieve emission. Therefore, when the light rays generated by the light emitting layer 13 transmit through the absorption polarizer 13, partial extinction occurs and the intensity of the light rays is reduced by 50%.

[0063] Thus, it can be seen that although the setting of the high-reflectivity electrode 11 can improve the light utilization rate, it will cause the reflection of ambient light and thus affect the light emission display effect; while the isolation structure that suppresses the reflection of ambient light will also affect the light emission efficiency of the light emitting unit, resulting in the problem of excessive energy consumption. Therefore, how to suppress ambient light while reducing the impact on the light emission efficiency of the light emitting unit is an urgent problem to be solved.

[0064] To solve the above technical problems, the present invention provides a light emitting structure, including:

[0065] A light emitting layer for emitting light rays; a first reflection surface located on one side of the light emitting layer for reflecting the light rays incident on the first reflection surface; and a reflection polarization layer located on the other side of the light emitting layer for reflecting the incident light rays with a first polarization direction and transmitting the incident light rays with a second polarization direction.

[0066] According to the technical solution of the present invention, the reflective polarizing layer can reflect incident light with a first polarization direction and transmit incident light with a second polarization direction; the light-emitting structure includes the reflective polarizing layer, so the light-emitting structure can generate light with a certain polarization orientation and has a high degree of integration, which is conducive to the miniaturization and high integration of linearly polarized light sources.

[0067] An embodiment of the present invention further provides a light-emitting unit comprising the light-emitting structure and an isolation structure. The isolation structure is located on the side of the reflective polarizing layer away from the light-emitting layer, and the isolation structure is suitable for adjusting the polarization direction of the transmitted light to isolate the ambient light reflected by the first reflective surface. In the light-emitting unit, the light-emitting structure is capable of generating linearly polarized light based on the light emitted by the light-emitting layer; the isolation structure isolates the ambient light by adjusting the polarization direction. By properly setting the polarization direction of the linearly polarized light generated by the light-emitting structure, it is possible to simultaneously suppress the transmission of ambient light while increasing the luminous intensity, thereby achieving the goal of both suppressing ambient light and increasing luminous intensity, which is beneficial to improving luminous efficiency and reducing energy consumption.

[0068] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0069] refer to Figure 4 , shows a schematic cross-sectional structure diagram of an embodiment of a light-emitting unit of the present invention.

[0070] The light emitting unit includes a light emitting structure 110 and an isolation structure 120. The light emitting structure 110 is suitable for generating light with a certain polarization orientation, and the isolation structure 120 is suitable for adjusting the polarization direction of the transmitted light to isolate ambient light.

[0071] The light-emitting structure 110 includes: a light-emitting layer 112, which is used to emit light; a first reflective surface 111a, which is located on one side of the light-emitting layer 112 and is used to reflect light incident on the first reflective surface 111a; and a reflective polarizing layer 113, which is located on the other side of the light-emitting layer 112 and is used to reflect incident light with a first polarization direction and transmit incident light with a second polarization direction.

[0072] The light emitting structure 110 includes the reflective polarizing layer 113 , so the light emitting structure 110 can generate light with a certain polarization orientation and has a high degree of integration, which is conducive to miniaturization and high integration of linearly polarized light sources.

[0073] The light-emitting layer 112 is adapted to generate light.

[0074] In some embodiments of the present invention, the light-emitting layer 112 may be at least one of an organic light-emitting layer, a quantum dot light-emitting layer, an electroluminescent layer, a Micro-LED light-emitting layer, and a plasma light-emitting layer. Specifically, in this embodiment, the light-emitting layer 112 is an organic light-emitting layer, that is, an OLED layer.

[0075] The first reflecting surface 111a is located on one side of the light-emitting layer 112 and is adapted to reflect the light incident on the first reflecting surface 111a.

[0076] The light generated by the light-emitting layer 112 can propagate to both sides of the light-emitting layer 112. Therefore, the setting of the first reflecting surface 111a can reflect the light generated by the light-emitting layer 112 and propagating toward the first reflecting surface 111a, so that as much light as possible generated by the light-emitting layer 112 propagates toward the other side, thereby achieving the purpose of improving the light-emitting efficiency.

[0077] It should be noted that in this embodiment, the light-emitting optical path of the light-emitting structure 110 extends along the A direction, that is, the light generated by the light-emitting layer 112 exits along the A direction. Therefore, the first reflecting surface 111a and the light-emitting layer 112 are arranged in sequence along the A direction.

[0078] In some embodiments of the present invention, the light-emitting structure 110 further includes: an electrode layer 111, and the surface of the electrode layer 111 facing the light-emitting layer 112 is the first reflecting surface 111a.

[0079] The electrode layer 110 is electrically connected to the light-emitting layer 112 to realize the connection between the light-emitting layer 112 and an external circuit.

[0080] In some embodiments of the present invention, the material of the electrode layer 110 is a high-reflectivity material. Generally speaking, the reflectivity of the electrode layer 110 to light is not less than 10%. Specifically, the material of the electrode layer 110 is metal.

[0081] The light generated by the light-emitting layer 112 propagates to both sides, that is, part of the light generated by the light-emitting layer 112 propagates along the light-emitting optical path direction A of the light-emitting structure 110, and part propagates in the direction opposite to the light-emitting optical path direction A of the light-emitting structure 110. The method of setting the material of the electrode layer 111 as a high-reflectivity material uses the existing electrode layer 111 to form the first reflecting surface 111a, which is simple and convenient, has little impact on the existing structure, can effectively control the process cost, and ensure the yield.

[0082] The reflection polarization layer 113 reflects incident light with a first polarization direction and transmits incident light with a second polarization direction, so that the light generated by the light-emitting structure 110 has a polarization orientation of the second polarization direction.

[0083] Since the reflection polarization layer 113 is integrated in the light-emitting structure 110, the light-emitting structure 110 can generate light with a certain polarization orientation, and has a high integration degree, which is beneficial to the miniaturization and high integration of the linear polarization light source.

[0084] In some embodiments of the present invention, the second polarization direction includes a polarization state orthogonal to the first polarization direction. In other embodiments of the present invention, the second polarization direction may also be a polarization state obliquely intersecting the first polarization direction.

[0085] With reference to Figure 4 and Figure 5 , in some embodiments of the present invention, the light-emitting structure 110 further includes: a second reflecting surface 113a, the second reflecting surface 113a is disposed opposite to the first reflecting surface 111a, and the second reflecting surface 113a is used for reflecting at least part of the light incident on the second reflecting surface 113a, so that the light emitted by the light-emitting layer 112 can propagate back and forth between the first reflecting surface 111a and the second reflecting surface 113a.

[0086] Specifically, as Figure 4 shown, in this embodiment, the surface of the reflection polarization layer 113 facing the light-emitting layer 112 is the second reflecting surface 113a. Using the existing film layer structure to form the second reflecting surface 113a is simple and convenient, and can change the design of the existing light-emitting structure as little as possible to form a polarization light-emitting cavity, which can effectively control the process cost and ensure the yield.

[0087] Specifically, among the light generated by the light-emitting layer 112, after part of the light propagating along the light-emitting optical path direction A of the light-emitting structure 110 is projected onto the reflection polarization layer 113, the reflection polarization layer 113 divides the light into P light parallel to the incident surface and S light perpendicular to the incident surface. Among them, the P light transmits through the reflection polarization layer 113 and exits from the light-emitting structure 110, while the S light is reflected by the second reflecting surface 113a and propagates in the direction opposite to the light-emitting optical path direction A of the light-emitting structure 110; the light propagating in the direction opposite to the light-emitting optical path of the light-emitting structure 110 is projected onto the electrode layer 111 and is reflected by the first reflecting surface 111a and then propagates along the light-emitting optical path direction A of the light-emitting structure 110.

[0088] Therefore, the first reflecting surface 111a and the second reflecting surface 113a are arranged opposite to each other to form a structure similar to a Fabry - Perot cavity; the light - emitting layer 112 is located between the first reflecting surface 111a and the second reflecting surface 113a and generates light. The light generated by the light - emitting layer 112 propagates in both directions. Among them, the light with the second polarization direction can exit from one side of the reflective polarization layer 113, and the light with the first polarization direction propagates back and forth between the first reflecting surface 111a and the second reflecting surface 113a.

[0089] Moreover, after the S - polarized light reflected by the second reflecting surface 113a is projected onto the first reflecting surface 111a, since the electrode layer 110 has a high reflectivity, the S - polarized light will be reflected again by the electrode layer 110 and thus become light propagating along the light - emitting optical path direction A of the light - emitting unit. Among them, a small part of the S - polarized light will be changed to P - polarized light due to the optical structure and finally exit from the reflective polarization layer 113. Therefore, the setting of the reflective polarization layer 113 can improve the efficiency of the light generated by the light - emitting layer 112 exiting from the light - emitting structure 110 (which can be seen from the graph line 702 in Figure 7 .

[0090] Specifically, in some embodiments of the present invention, the reflective polarization layer 113 is a reflective type polarizing brightness enhancement film (Dual Brightness Enhancement Film, DBEF), or a polarizer composed of a highly reflective metal grid, or a polarizer formed based on a photonic crystal with different optical bandgaps and passbands designed for different polarizations, etc.

[0091] Continue to refer to Figure 4 and Figure 5 , in some embodiments of the present invention, the light - emitting structure 110 further includes: a deflection layer 114. The deflection layer 114 is located between the reflective polarization layer 113 and the light - emitting layer 112, and the deflection layer 114 is adapted to change the polarization state of the light transmitted through the deflection layer 114 compared to the polarization state of the light incident on the deflection layer 114.

[0092] The deflection layer 114 can change the polarization state of the transmitted light compared to the polarization state of the incident light. Therefore, the combination of the deflection layer 114 and the reflective polarization layer 113 can make as much light as possible generated by the light - emitting layer 112 exit from the light - emitting structure 110, effectively improving the light - emitting efficiency and effectively reducing the energy consumption.

[0093] In some embodiments of the present invention, the deflection layer changes the polarization state of the light transmitted through the deflection layer including: the deflection layer changes the energy distribution of the light transmitted through the deflection layer in each polarization direction.

[0094] In some embodiments of the present invention, the polarization state change of the light transmitted through the deflection layer includes: the deflection layer changes the polarization direction of the light transmitted through the deflection layer compared to the polarization direction of the light incident on the deflection layer, and / or generates a phase difference between different components of the light transmitted through the deflection layer.

[0095] In some embodiments of the present invention, the material of the deflection layer 114 is a light-transmitting material film layer with birefringence properties. The deflection layer 114 rotates the polarization direction of the transmitted light by 90° or other required degrees. In some other embodiments of the present invention, the deflection layer can also be formed by plasmonics, that is, using conductors with high electrical conductivity to make different nano-scale properties, thereby affecting the phase and polarization of light propagation. The plasmonics is a nano-scale metal structure, which uses different properties to change the properties of light waves such as the polarization state by absorbing and reflecting electromagnetic waves. The main principle is that only the polarization state perpendicular to the interface and along the normal direction of the light wave does not excite the plasmonic effect. The polarization state along the tangent direction of the surface will drive the electrons to move, so it is coupled with the conductive characteristics of the metal to form a plasmonic state. This state has the characteristics of electrons at the nano-scale and is coupled with the light characteristics. Its intrinsic wavelength is very small, and imaging and other mechanisms that can exceed the wavelength of light waves can be formed.

[0096] Specifically, the deflection layer 114 includes at least one of materials such as a half-wave plate, an electro-optic crystal layer, a polarization anisotropic photonic crystal layer, etc. that can generate different phases for light with different polarization directions. The half-wave plate is equivalent to generating an odd multiple of λ / 2 phase difference between the fast axis and the slow axis of the optical device, that is, the phase of one polarization direction increases by π (180 degrees) relative to the other polarization direction. Birefringent crystals can be used to produce this effect, including fast and slow axis optical crystals / materials.

[0097] The deflection layer 114 can deflect the polarization direction of the transmitted light relative to the incident light. When the light propagates back and forth between the first reflective layer 111a and the second reflective layer 113a, its polarization direction is deflected multiple times by the deflection layer 114 until it exits from the light-emitting structure 110. In the embodiment of the present invention, after adding a deflection layer 114, such as a half-wave plate, between the reflective polarization layer and the high-reflectivity electrode in the optical cavity, each time the light passes through the half-wave plate, the polarization direction of the light will rotate by an angle, and finally the polarization direction will be completely changed to the exit direction. Theoretically, if there is no electrode absorption loss and no other scattering losses, etc., there will be twice the polarized outgoing light. Therefore, the setting of the deflection layer 114 can enable as much light generated by the light-emitting layer 112 to exit from the light-emitting structure 110 as possible, and even enable the light generated by the light-emitting layer 112 to exit from the light-emitting structure 110 at a proportion close to 100%, thereby effectively improving the utilization rate of the light generated by the light-emitting layer 112, improving the luminous efficiency, and reducing the energy consumption.

[0098] Continuing to refer to Figure 4 , the light-emitting unit further includes: an isolation structure 120 for isolating the reflection of ambient light.

[0099] The isolation structure 120 is located downstream of the light-emitting path of the light-emitting structure 110, that is, the isolation structure 120 is located on the side of the reflective polarization layer 113 away from the light-emitting layer 112. The isolation structure 120 is suitable for adjusting the polarization direction of the transmitted light to isolate the ambient light reflected by the first reflective surface 111a.

[0100] Since the light-emitting structure 110 can generate linearly polarized light based on the light emitted by the light-emitting layer 112; the isolation structure 120 isolates the ambient light by adjusting the polarization direction. By reasonably setting the polarization direction of the linearly polarized light generated by the light-emitting structure 110, it is possible to suppress the ambient light while increasing the luminous intensity, thereby achieving the purpose of both suppressing the ambient light and increasing the luminous intensity, which is beneficial to improving the luminous efficiency of the light-emitting unit and reducing the energy consumption.

[0101] The isolation structure 120 is located downstream of the light-emitting path of the light-emitting structure 110, as Figure 4 and Figure 5 shown, the light generated by the light-emitting structure 110 exits after passing through the isolation structure. As Figure 6 shown, the incident light path of the far-field light (such as ambient light) is opposite to the light-emitting path of the light-emitting structure 110. The isolation structure not only prevents the far-field light from being reflected on the surface of the isolation structure, but also prevents the far-field light from being reflected inside the light-emitting structure.

[0102] In some embodiments of the present invention, the isolation structure 120 includes: a quarter-wave plate 121 and an absorbing polarizer 122, to form a non-magnetic (Faraday) optical isolator design, so that the incident ambient light cannot return to the original incident direction, to eliminate the reflection of the high-reflectivity electrode to the ambient light, so that the light emitted by the light-emitting structure can be utilized.

[0103] With reference to Figure 5 , the outgoing light generated by the light-emitting structure 110 is incident on the quarter-wave plate 121 and the absorbing polarizer 122 in sequence and then exits; with reference to Figure 6 , the far-field light is incident on the inside of the light-emitting structure 110 by transmitting through the absorbing polarizer 122 and the quarter-wave plate 121 in sequence.

[0104] As Figure 6 shown, the far-field light (such as ambient light) is generally natural light, that is, the far-field light includes all possible polarization states perpendicular to the propagation direction. Therefore, after the far-field light transmits through the absorbing polarizer 122, some light with a polarization direction different from that of the absorbing polarizer 122 is absorbed by the absorbing polarizer 122 and cannot transmit, and some light with a polarization direction the same as that of the absorbing polarizer 122 transmits through the absorbing polarizer 122 and is incident on the inside of the light-emitting structure to form incident far-field light 100a, and the incident far-field light 100a is linearly polarized light with a polarization direction the same as that of the absorbing polarizer 122.

[0105] In some embodiments of the present invention, the angle between the polarization direction of the absorbing polarizer 122 and the optical axis direction of the quarter-wave plate 121 is 45° (as shown in Figure 5 ), therefore, the incident far-field light 100a forms circularly polarized far-field light 100b after transmitting through the quarter-wave plate 121 and is projected onto the light-emitting structure 110, and the circularly polarized far-field light 100b is circularly polarized light (as shown in Figure 6 ). The optical axis direction of the quarter-wave plate 121 is located in a plane perpendicular to the light propagation direction.

[0106] As Figure 6As shown, after the circular remote field light 100b is projected onto the reflective polarization layer 113, it is divided by the reflective polarization layer 113 into P light parallel to the incident plane and S light perpendicular to the incident plane. Among them, the P light transmits through the reflective polarization layer 113 and enters the light-emitting structure 110, while the S light is reflected by the reflective polarization layer 113; the P light incident on the light-emitting structure 110 is reflected by the electrode layer 111 after successively transmitting through the deflection layer 114 and the light-emitting layer 112, and then exits from the reflective polarization layer 113 again; since the deflection layer 114 increases the phase of one polarization direction of the transmitted light by π (180 degrees) relative to the other polarization direction, the difference in the phase of one polarization direction of the light exiting from the reflective polarization layer 113 relative to the phase of the other polarization direction is 2π. Therefore, at least part of the light exiting from the reflective polarization layer 113 is still P light.

[0107] The light exiting from the reflective polarization layer 113 combines with the S light directly reflected by the reflective polarization layer 113 to form circularly polarized light. That is to say, the refolded remote field light 100c finally projected onto the isolation structure is still circularly polarized light.

[0108] After the refolded remote field light 100c transmits through the quarter-wave plate 121, it forms a returned remote field light 100d. The polarization state of the returned remote field light 100d is restored to linearly polarized light, but compared with the polarization direction of the incident remote field light 100a, the polarization direction of the returned remote field light 100d is rotated by 90°. That is to say, the polarization direction of the returned remote field light 100d is orthogonal to the polarization direction of the incident remote field light 100a; therefore, when the returned remote field light 100d transmits through the absorption polarizer 122, an extinction phenomenon will occur, and the reflection of ambient light is suppressed.

[0109] Continue to refer to Figure 5 , the light emitted from the light-emitting layer 112 in the light emitted by the light-emitting structure 110 forms elliptically polarized light 200b after transmitting through the quarter-wave plate 121. Specifically, the outgoing light 200a with a polarization orientation higher than normal in the light generated by the light-emitting structure 110 is linearly polarized light with multiple polarization directions. For normal natural light, its outgoing polarization state is randomly emitted without a specific direction. That is, described by the polarization state, the components on two orthogonal polarization states are equal. Here, the so-called "higher than normal polarization orientation" means that under two orthogonal polarization states, the energy distribution of a certain light component is higher than that of the other light component. When the polarization direction of the outgoing light 200a is neither on the optical axis of the quarter-wave plate 121 nor at an angle of 45° with the optical axis of the quarter-wave plate 121, the outgoing light 200a forms outgoing elliptically polarized light 200b after transmitting through the quarter-wave plate 121.

[0110] When the emitted elliptical polarized light 200b passes through the absorption polarizer 122, the part of the light rays with the same polarization direction as the polarization direction 140 of the absorption polarizer exits to form the emitted light 200c of the light-emitting unit. Since the emitted light 200c is formed by the transmitted absorption polarizer 122 of the emitted elliptical polarized light 200b with an elliptical polarization state, compared with the technical solution where light rays with a natural light polarization state pass through the absorption polarizer 122, the proportion of the light rays that undergo extinction is lower, and the proportion of the transmitted light rays is higher. That is to say, more light rays can exit, thereby effectively improving the light-emitting efficiency of the light-emitting unit and reducing energy consumption. In some embodiments, the major axis direction of the ellipse describing the elliptical polarization state of the emitted elliptical polarized light 200b forms an angle less than 45° with the polarization direction of the absorption polarizer 122, and the proportion of the emitted elliptical polarized light 200b passing through the absorption polarizer 122 is greater than or equal to 85%.

[0111] As Figure 5 Described above, in some embodiments of the present invention, the angle α between the polarization direction of the absorption polarizer 122 and the optical axis direction of the quarter-wave plate 121 is twice the angle between the optical axis direction of the quarter-wave plate and the polarization direction of the linearly polarized light generated by the light-emitting structure, so as to better achieve the effect of suppressing the transmission of ambient light while increasing the light-emitting intensity.

[0112] Specifically, the angle α between the polarization direction of the absorption polarizer 122 and the optical axis direction of the quarter-wave plate 121 is twice the angle β between the optical axis direction of the quarter-wave plate 121 and the optical axis direction or the polarization direction of the reflection polarization layer 113 of the light-emitting structure. Therefore, the polarization direction of the light rays emitted from the light-emitting layer 112 in the emitted light rays generated by the light-emitting structure 110 is not in the optical axis direction of the quarter-wave plate and not in the direction forming a 45-degree angle with the optical axis of the quarter-wave plate.

[0113] In this embodiment, the angle between the polarization direction of the absorption polarizer 122 and the optical axis direction of the quarter-wave plate 121 is 45°; therefore, the angle between the optical axis direction or the polarization direction of the reflection polarization layer 113 of the light-emitting structure and the polarization direction of the absorption polarizer 122 is 22.5°; so, the polarization direction of the light rays emitted from the light-emitting layer 112 in the emitted light rays generated by the light-emitting structure 110 forms an angle of 22.5° with the polarization direction of the absorption polarizer 122 or with the optical axis direction of the quarter-wave plate 121

[0114] Refer to Figure 7 , which shows the relationship diagram between the light-emitting intensity and the light-emitting angle of different-structured light-emitting units.

[0115] The horizontal axis in the figure represents the light-emitting angle in degrees; the vertical axis represents the light-emitting brightness in cd / m 2 . Curve 701 is Figure 1 a graph showing the relationship between the light-emitting intensity and the light-emitting angle of the shown light-emitting unit; curve 702 is Figure 1 a graph showing the relationship between the light-emitting intensity and the light-emitting angle of the light-emitting unit after adding a reflective polarization layer; curve 703 is Figure 4 a graph showing the relationship between the light-emitting intensity and the light-emitting angle of the shown light-emitting unit embodiment.

[0116] Comparing curve 701 and curve 702, it can be known that on the basis of the Figure 1 shown light-emitting structure, adding a reflective polarization layer can increase the light-emitting intensity of the emitted light, and at the same time can achieve a higher light-emitting intensity within a larger range of light-emitting angles, that is, it can improve the light-emitting efficiency; however, after comparing curve 703, curve 702 and curve 701, it can be known that Figure 4 the shown light-emitting structure embodiment can more significantly improve the light-emitting intensity, improve the light-emitting efficiency, and at the same time the light-emitting angle is more concentrated. Specifically, on the premise of not considering light energy loss, Figure 4 the shown light-emitting unit can make nearly 85% of the light generated by the light-emitting layer exit.

[0117] Correspondingly, the present invention also provides a display device, including: at least one display pixel, and the display pixel includes the light-emitting structure of the present invention or the light-emitting unit of the present invention.

[0118] In a specific embodiment, the display device includes: a mobile terminal display screen, a computer display screen, a TV display screen, an advertising display screen, a vehicle-mounted display screen, a control screen of an instrument or meter, or a control screen of an aircraft, etc.

[0119] In addition, the present invention also provides an electronic device, specifically including: the display device of the present invention.

[0120] In a specific embodiment, the electronic device includes: a mobile terminal, a computer, a vehicle-mounted electronic device, a control device of an instrument or meter, an electronic advertising system, or a TV, etc. The display device can be applied to various electronic devices, can effectively reduce the energy consumption of the electronic device, improve the battery life of the electronic device, and improve the performance of the electronic device.

[0121] In summary, the reflective polarizing layer can reflect incident light with a first polarization direction and transmit incident light with a second polarization direction; the light-emitting structure includes the reflective polarizing layer, so the light-emitting structure can generate light with a certain polarization orientation, and has a high degree of integration, which is conducive to the miniaturization and high integration of linearly polarized light sources. In the light-emitting unit, the light-emitting structure can generate linearly polarized light based on the light emitted by the light-emitting layer; the isolation structure isolates ambient light by adjusting the polarization direction. By reasonably setting the polarization direction of the linearly polarized light generated by the light-emitting structure, it is possible to suppress the transmission of ambient light while increasing the luminous intensity, thereby achieving the purpose of both suppressing ambient light and increasing luminous intensity, which is conducive to improving luminous efficiency and reducing energy consumption.

[0122] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A light-emitting unit, characterized in that, Comprising: A light-emitting structure; An isolation structure located on the side of the reflective polarization layer away from the light-emitting layer, the isolation structure being adapted to adjust the polarization direction of the transmitted light to isolate the ambient light reflected by the first reflective surface; The light-emitting structure includes: A light-emitting layer for emitting light; A first reflective surface located on one side of the light-emitting layer, the first reflective surface being adapted to reflect the light incident on the first reflective surface; A reflective polarization layer located on the other side of the light-emitting layer, the reflective polarization layer being adapted to reflect the incident light with a first polarization direction and transmit the incident light with a second polarization direction; The isolation structure includes: a quarter-wave plate and an absorption polarizer; The included angle between the polarization direction of the absorption polarizer and the optical axis direction of the quarter-wave plate is twice the included angle between the optical axis direction of the quarter-wave plate and the polarization direction of the light emitted from the light-emitting layer in the emitted light generated by the light-emitting structure.

2. The light-emitting unit according to claim 1, wherein, The light-emitting structure further includes: An electrode layer, the surface of the electrode layer facing the light-emitting layer being the first reflective surface.

3. The light-emitting unit according to claim 1, characterized in that, The second polarization direction includes a polarization state orthogonal to the first polarization direction.

4. The light-emitting unit according to claim 1, characterized in that, The reflective polarization layer includes a reflective type polarizing brightness enhancement film or a polarizer composed of a highly reflective metal grid, or a polarizer formed based on different optical bandgaps and passbands designed for different polarizations of a photonic crystal.

5. The light-emitting unit according to claim 1, wherein The light-emitting structure further includes: a deflection layer located between the reflective polarization layer and the light-emitting layer, the deflection layer being adapted to change the polarization state of the light transmitted through the deflection layer compared to the polarization state of the light incident on the deflection layer.

6. The light-emitting unit according to claim 5, wherein, The deflection layer changing the polarization state of the light transmitted through the deflection layer includes: the deflection layer changing the energy distribution of the light transmitted through the deflection layer in each polarization direction.

7. The light emitting unit according to claim 5, characterized in that The deflection layer changing the polarization state of the light transmitted through the deflection layer includes: the deflection layer changing the polarization direction of the light transmitted through the deflection layer compared to the polarization direction of the light incident on the deflection layer, and / or generating a phase difference between different components of the light transmitted through the deflection layer.

8. The light-emitting unit according to claim 5, characterized in that, The deflection layer includes at least one of a half-wave plate, an electro-optic crystal layer, and a polarization anisotropic photonic crystal layer.

9. The light-emitting unit according to claim 5, characterized in that, The deflection layer is formed of a light-transmitting material with birefringence properties or a plasma.

10. The light-emitting unit according to claim 2, wherein The material of the electrode layer is a high-reflectivity material.

11. The light-emitting unit according to claim 1, characterized in that, The light-emitting layer includes at least one of an organic light-emitting layer, a quantum dot light-emitting layer, an electroluminescent layer, a Micro-LED light-emitting layer, and a plasma light-emitting layer.

12. The light-emitting unit according to claim 1, wherein, Further comprising: A second reflective surface disposed opposite to the first reflective surface, the second reflective surface being adapted to reflect at least part of the light incident on the second reflective surface, so that the light emitted by the light-emitting layer can propagate back and forth between the first reflective surface and the second reflective surface.

13. The light-emitting unit according to claim 12, wherein, The surface of the reflective polarization layer facing the light-emitting layer is the second reflective surface.

14. The light-emitting unit according to claim 1, wherein The emitted light generated by the light-emitting structure is incident on the quarter-wave plate and the absorption polarizer in sequence, and the included angle between the polarization direction of the absorption polarizer and the optical axis direction of the quarter-wave plate is 45°.

15. The light-emitting unit according to claim 14, characterized in that, Among the emitted light generated by the light-emitting structure, the light emitted from the light-emitting layer forms elliptically polarized light after passing through the quarter-wave plate.

16. The light-emitting unit according to claim 15, characterized in that, The included angle between the major axis direction of the ellipse of the elliptically polarized light and the polarization direction of the absorption polarizer is less than 45°.

17. The light-emitting unit according to claim 14, 15 or 16, characterized in that, Among the emitted light generated by the light-emitting structure, the polarization direction of the light emitted from the light-emitting layer is not in the optical axis direction of the quarter-wave plate, nor in the direction forming a 45-degree angle with the optical axis of the quarter-wave plate.

18. The light-emitting unit according to claim 17, wherein, Among the emitted light generated by the light-emitting structure, the included angle between the polarization direction of the light emitted from the light-emitting layer and the polarization direction of the absorption polarizer, or the optical axis direction of the quarter-wave plate is 22.5°.

19. A display device, characterized in that, Comprising: At least one display pixel, and the display pixel includes the light-emitting unit according to any one of claims 1 to 18.

20. The display device according to claim 19, wherein, Comprising: A mobile terminal display screen, a computer display screen, a television display screen, an advertising display screen, a vehicle-mounted display screen, a control screen of an instrument or meter, or a control screen of an aircraft.

21. An electronic device, characterized in that, Comprising: The display device according to claim 19 or 20.

22. The electronic device according to claim 21, characterized in that, Comprising a mobile terminal, a computer, a vehicle-mounted electronic device, a control device of an instrument or meter, an electronic advertising system, or a television.

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