Display device

Abstract

A display device includes a circuit substrate, a light-emitting layer, a polarizing layer, a quarter-wave plate, and a bandpass polarized reflective layer. The light-emitting layer has a plurality of light-emitting structures. The plurality of light-emitting structures include a plurality of first light-emitting structures. The polarizing layer is located on the side of the light-emitting layer away from the circuit substrate. The quarter-wave plate is disposed between the polarizing layer and the light-emitting layer, and overlaps the light-emitting layer and the polarizing layer. The bandpass polarized reflective layer is disposed between the quarter-wave plate and the light-emitting layer, and includes a first bandpass polarized reflective pattern overlapping the plurality of first light-emitting structures. The reflectivity of the first bandpass polarized reflective pattern for light with a wavelength within a first wavelength range is greater than 20%. The first wavelength range is the first main light-emitting wavelength of the first light-emitting structure ±10 nm. The display device provided by the present invention can take into account both light energy utilization and dark state contrast.

Description

Technical Field

[0001] The present invention relates to an electronic device, and more particularly to a display device. Background Art

[0002] In recent years, organic light-emitting diode (OLED) display panels and micro light-emitting diode display (Micro LED Display) panels have gradually gained popularity due to their high color saturation, fast response speed, and high contrast display quality. To increase the light extraction efficiency of such self-emitting display panels, the electrodes on the side of the light-emitting diodes away from the light-emitting surface are mostly reflective electrodes. Since such reflective electrodes reflect external ambient light, when the display panel shows a full black screen or local dark states, the human eye is prone to detect the external ambient light reflected by the reflective electrodes, resulting in a decline in display quality or appearance taste.

[0003] To solve the above problems, a technical solution of setting a circular polarizer on one side of the light-emitting surface of the self-emitting display panel is proposed. By setting the circular polarizer, the passing external ambient light forms circularly polarized light with a specific chirality, and this circularly polarized light forms circularly polarized light with a reverse chirality after being reflected by the reflective electrode, and this circularly polarized light with a reverse chirality cannot pass through the circular polarizer. Accordingly, the reflectivity of such self-emitting display panels to external ambient light is reduced. However, such circular polarizers will reduce the overall light output of the self-emitting display panels, for example, causing the light output brightness to decay by at least 55%. Summary of the Invention

[0004] The present invention provides a display device that can balance light energy utilization efficiency and dark state contrast.

[0005] To achieve one or part or all of the above purposes or other purposes, an embodiment of the present invention provides a display device. The display device includes a circuit board, a light-emitting layer, a polarizing layer, a quarter-wave plate, and a band-pass polarization reflection layer. The light-emitting layer is disposed on the circuit board and has a plurality of light-emitting structures. These light-emitting structures are electrically connected to the circuit board and include a plurality of first light-emitting structures. These first light-emitting structures have a first main emission wavelength. The polarizing layer is overlapped with the light-emitting layer and is located on the side of the light-emitting layer away from the circuit board. The quarter-wave plate is disposed between the polarizing layer and the light-emitting layer and overlaps with the light-emitting layer and the polarizing layer. The band-pass polarization reflection layer is disposed between the quarter-wave plate and the light-emitting layer. The band-pass polarization reflection layer includes a first band-pass polarization reflection pattern that overlaps with these first light-emitting structures. The reflectivity of the first band-pass polarization reflection pattern to light with wavelengths in a first wavelength range is greater than 20%. The first wavelength range is the first main emission wavelength ± 10 nm.

[0006] Based on the above, in the display device according to an embodiment of the present invention, a band-pass polarizing reflection layer is provided between the quarter-wave plate and the light-emitting layer and at a position overlapping the light-emitting structure. Accordingly, the overall reflectivity of the display device to external ambient light can be effectively reduced, and at the same time, the light energy loss of the polarizing layer to the internal display light can be reduced, thereby improving the light energy utilization rate and the dark state performance of the display device.

[0007] To make the above features and advantages of the present invention more obvious and understandable, specific embodiments are hereinafter given and described in detail in conjunction with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figures 1A to 1C is a cross-sectional schematic view of a display device according to a first embodiment of the present invention.

[0009] Figure 2 is a cross-sectional schematic view of a band-pass polarizing reflection layer according to a first embodiment of the present invention.

[0010] Figure 3A and Figure 3B is Figure 2 a cross-sectional schematic view of some modified embodiments of the band-pass polarizing reflection layer.

[0011] Figure 4 is a cross-sectional schematic view of a display device according to a second embodiment of the present invention.

[0012] Figure 5 is a cross-sectional schematic view of a display device according to a third embodiment of the present invention.

[0013] Figure 6 is a cross-sectional schematic view of a display device according to a fourth embodiment of the present invention.

[0014] Figure 7 is Figure 6 a graph of the reflectivity of the band-pass polarizing reflection layer against wavelength.

[0015] Figure 8 is Figure 6 a graph of the optical power against wavelength of the display device and a display device of a comparative example at different light-emitting wavelengths.

[0016] Figure 9 is the ambient light and the optical power against wavelength of the ambient light reflected by the display device via Figure 6 the display device.

[0017] Figure 10 is Figure 6 a graph of the ambient light reflectivity of the display device against the reflectivity of its reflective electrode layer.

[0018] Figure 11 is Figure 7Graph of reflectance versus wavelength for another modified embodiment of the band-pass polarizing reflection layer.

[0019] Figure 12 Is a cross-sectional schematic view of a display device according to a fifth embodiment of the present invention.

[0020] Figure 13 Is a cross-sectional schematic view of a display device according to a sixth embodiment of the present invention.

[0021] Figure 14 Is a cross-sectional schematic view of a display device according to a seventh embodiment of the present invention.

[0022] Figure 15 Is a cross-sectional schematic view of a display device according to an eighth embodiment of the present invention. Detailed Description of the Preferred Embodiment

[0023] Regarding the foregoing and other technical contents, features, and effects of the present invention, they will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front, or back, etc., are only with reference to the directions in the drawings. Therefore, the directional terms used are for illustration and not for limiting the present invention.

[0024] Figures 1A to 1C Is a cross-sectional schematic view of a display device according to a first embodiment of the present invention. Figure 2 Is a cross-sectional schematic view of a band-pass polarizing reflection layer according to a first embodiment of the present invention. Figure 3A And Figure 3B Is Figure 2 Cross-sectional schematic views of other modified embodiments of the band-pass polarizing reflection layer.

[0025] Please refer to Figure 1A , the display device 10 includes a circuit board 100, a light-emitting layer EML, a polarizing layer 110, and a quarter-wave plate 120. The light-emitting layer EML is disposed on the circuit board 100. The light-emitting layer EML has a plurality of light-emitting structures, and these light-emitting structures are electrically connected to the circuit board 100. In this embodiment, the circuit board 100 includes, for example, a driving circuit layer (not shown) that can individually control a plurality of display pixels. Further, the light-emitting layer EML may include a plurality of light-emitting structures ES1, a plurality of light-emitting structures ES2, a plurality of light-emitting structures ES3, a first electrode layer E1, and a second electrode layer E2. These light-emitting structures ES1, these light-emitting structures ES2, and these light-emitting structures ES3 are, for example, alternately arranged in sequence along the direction X and serve as a plurality of display pixels. The plurality of light-emitting structures arranged along the direction Y are, for example, the same type of light-emitting structure or alternately arranged, but the present invention is not limited thereto. In other embodiments, the display device 10 may be a monochromatic grayscale display or a black-and-white grayscale display, meaning that the display device 10 may only include one type of light-emitting structure.

[0026] For example, the light-emitting structures ES1, ES2, and ES3 are adapted to emit excitation lights with different main emission wavelengths, such as red light (e.g., light with a main emission wavelength greater than 600 nm), green light (e.g., light with a main emission wavelength between 500 nm and 600 nm), and blue light (e.g., light with a main emission wavelength less than 500 nm), and the light mixing is performed with different light intensity ratios by these lights to achieve the effect of color display. That is to say, the display device 10 of this embodiment is a self-luminous display, such as an organic light emitting diode (OLED) display, but not limited thereto. In other embodiments, the display device 10 may also be a micro light emitting diode (micro-LED) display or a mini light emitting diode (mini-LED) display.

[0027] In this embodiment, the first electrode layer E1 and the second electrode layer E2 are respectively disposed on opposite sides of the plurality of light-emitting structures, and these two electrode layers are electrically connected to these light-emitting structures. For example, the first electrode layer E1 is located between these light-emitting structures and the circuit board 100, and is, for example, a planar electrode. The second electrode layer E2 is, for example, a plurality of electrode patterns respectively overlapping these light-emitting structures, and these electrode patterns are respectively electrically connected to a plurality of active elements (not shown) of the circuit board 100. More specifically, the currents flowing through these light-emitting structures can be individually controlled via these active elements to produce the same or different light emission intensities to achieve the display effect.

[0028] The first electrode layer E1 is, for example, a reflective electrode layer, and the material of the reflective electrode layer includes metal, alloy, nitride of metal material, oxide of metal material, oxynitride of metal material, or other suitable materials, or a stacked layer of metal material and other conductive materials. The second electrode layer E2 is, for example, a light-transmissive electrode layer, and the material of the light-transmissive electrode layer includes metal oxides, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or other suitable oxides, or a stacked layer of at least two of the above.

[0029] In this embodiment, the polarizing layer 110 has an absorption axis AX, and the angle between the axial direction of this absorption axis AX and the axial direction of the optical axis (not shown) of the quarter-wave plate 120 is 45 degrees, but it is not limited thereto. The polarizing layer 110 is overlapped and disposed on the light-emitting layer EML, and is located on the side of the light-emitting layer EML away from the circuit board 100. The quarter-wave plate 120 of the display device 10 is overlapped and disposed on the plurality of light-emitting structures (such as the light-emitting structure ES1, the light-emitting structure ES2, and the light-emitting structure ES3) of the light-emitting layer EML and the polarizing layer 110, and is located between the polarizing layer 110 and the light-emitting layer EML. It is worth mentioning that the quarter-wave plate 120 of the present invention can be a combination of multiple compensation films, such as a combination of a quarter-wave plate and a half-wave plate. In this embodiment, in order to protect the light-emitting layer EML, the display device 10 may also selectively include a packaging layer 140 disposed between the light-emitting layer EML and the quarter-wave plate 120, and the packaging layer 140 covers the light-emitting layer EML, but it is not limited thereto.

[0030] Furthermore, the display device 10 further includes a band-pass polarizing reflection layer 130 and a light-transmitting adhesive layer 150 disposed between the quarter-wave plate 120 and the light-emitting layer EML. In this embodiment, the band-pass polarizing reflection layer 130 may include a plurality of band-pass polarizing reflection patterns, such as a plurality of band-pass polarizing reflection patterns 131, a plurality of band-pass polarizing reflection patterns 132, and a plurality of band-pass polarizing reflection patterns 133 alternately arranged along the direction X. The light-transmitting adhesive layer 150 covers these band-pass polarizing reflection patterns.

[0031] More specifically, these band-pass polarizing reflection patterns 131 respectively overlap the plurality of light-emitting structures ES1, these band-pass polarizing reflection patterns 132 respectively overlap the plurality of light-emitting structures ES2, and these band-pass polarizing reflection patterns 133 respectively overlap the plurality of light-emitting structures ES3. It should be noted that the overlapping relationship between the two components here means that the projections of the two components along the direction Z overlap. If not specifically mentioned hereinafter, the overlapping relationship between the two components is defined in the same way, so it will not be elaborated.

[0032] In this embodiment, the reflectivity of the band-pass polarizing reflection pattern 131 for light with a wavelength in the first wavelength range is greater than 20%, and the first wavelength range is the main emission wavelength of the light-emitting structure ES1 ± 10 nm (such as 610 nm to 630 nm). The reflectivity of the band-pass polarizing reflection pattern 132 for light with a wavelength in the second wavelength range is greater than 20%, and the second wavelength range is the main emission wavelength of the light-emitting structure ES2 ± 10 nm (such as 515 nm to 535 nm), and the main emission wavelength of the light-emitting structure ES1 is different from the main emission wavelength of the light-emitting structure ES2. The reflectivity of the band-pass polarizing reflection pattern 133 for light with a wavelength in the third wavelength range is greater than 20%, and the third wavelength range is the main emission wavelength of the light-emitting structure ES3 ± 10 nm (such as 450 nm to 470 nm).

[0033] It should be particularly noted that these band-pass polarized reflection patterns do not produce a substantial reflection effect on light rays with wavelengths outside the above wavelength range. For example, when the unpolarized light ray LB1 from the light-emitting structure ES1 is incident on the band-pass polarized reflection pattern 131, a part of the light ray LB1 will directly pass through the band-pass polarized reflection pattern 131 and form a light ray LB1a with a first circular polarization state CP1, while another part of the light ray LB1 will be reflected by the band-pass polarized reflection pattern 131 and form a light ray LB1b with a second circular polarization state CP2. That is to say, the band-pass polarized reflection pattern 131 will reflect the light component with the second circular polarization state CP2 in the light ray LB1 and allow the light component with the first circular polarization state CP1 in the light ray LB1 to pass through.

[0034] After the light ray LB1a from the band-pass polarized reflection pattern 131 passes through the quarter-wave plate 120, its polarization state will change from the first circular polarization state CP1 to the first linear polarization state LP1. Since the polarization direction of the first linear polarization state LP1 is perpendicular to the axial direction of the absorption axis AX of the polarizing layer 110, the light ray LB1a can directly pass through the polarizing layer 110 and exit the display device 10. On the other hand, after the light ray LB1b reflected by the band-pass polarized reflection pattern 131 is reflected by the first electrode layer E1, its polarization state will change from the second circular polarization state CP2 to the first circular polarization state CP1. At this time, the light ray LB1b with the first circular polarization state CP1 can directly pass through the band-pass polarized reflection pattern 131 and form a light ray LB1b with the first linear polarization state LP1 after passing through the quarter-wave plate 120. Therefore, the light ray LB1b reflected by the band-pass polarized reflection pattern 131 and the first electrode layer E1 can also pass through the polarizing layer 110 and exit the display device 10. In other words, the setting of the band-pass polarized reflection pattern 131 does not cause a substantial loss of light energy for the light ray LB1 emitted by the light-emitting structure ES1.

[0035] Since the effect of the band-pass polarized reflection pattern 132 on the light ray from the light-emitting structure ES2 and the effect of the band-pass polarized reflection pattern 133 on the light ray from the light-emitting structure ES3 are similar to the effect of the band-pass polarized reflection pattern 131 on the light ray LB1, they will not be elaborated here.

[0036] Please refer to Figure 1B, on the other hand, the ambient light EB1 from the outside with an unpolarized state forms a light ray with the first circular polarization state CP1 after passing through the polarizing layer 110 and the quarter-wave plate 120. It should be particularly noted that when the wavelength of the ambient light EB1 is outside the aforementioned first wavelength range, regardless of the polarization state of the ambient light EB1, the band-pass polarization reflection pattern 131 will not substantially reflect the ambient light EB1. For example, the ambient light EB1 passing through the polarizing layer 110 and the quarter-wave plate 120 with the first circular polarization state CP1 and the ambient light EB1 reflected by the first electrode layer E1 with the second circular polarization state CP2 can directly pass through the band-pass polarization reflection pattern 131.

[0037] After the ambient light EB1 from the band-pass polarization reflection pattern 131 passes through the quarter-wave plate 120, its polarization state changes from the second circular polarization state CP2 to the second linear polarization state LP2. Since the polarization direction of the second linear polarization state LP2 is parallel to the axial direction of the absorption axis AX of the polarizing layer 110, the ambient light EB1 reflected by the first electrode layer E1 cannot exit the display device 10. For example, the ambient light EB1 can be green light or blue light with a wavelength outside the first wavelength range, but not limited thereto.

[0038] Please refer to Figure 1C , when the wavelength of the ambient light EB2 is within the aforementioned first wavelength range, a part of the ambient light EB2 exits the display device 10 after one reflection by the band-pass polarization reflection pattern 131 and two reflections by the first electrode layer E1. Specifically, the ambient light EB2 forms a light ray with the first circular polarization state CP1 after passing through the polarizing layer 110 and the quarter-wave plate 120. After this ambient light EB2 with the first circular polarization state CP1 passes through the band-pass polarization reflection pattern 131 and is reflected by the first electrode layer E1, its polarization state changes from the first circular polarization state CP1 to the second circular polarization state CP2. Therefore, the ambient light EB2 with the second circular polarization state CP2 can be reflected back to the first electrode layer E1 by the band-pass polarization reflection pattern 131, and after the second reflection by the first electrode layer E1, it forms a light ray with the first circular polarization state CP1. This ambient light EB2 with the first circular polarization state CP1 passes through the band-pass polarization reflection pattern 131 and the quarter-wave plate 120 again to form a light ray with the first linear polarization state LP1, and exits the display device 10 through the polarizing layer 110.

[0039] Since the effects of the band-pass polarization reflection pattern 132 and the band-pass polarization reflection pattern 133 on the external ambient light are similar to the effects of the band-pass polarization reflection pattern 131 on the external ambient light, they will not be elaborated here.

[0040] Please also refer to Figures 1A to 1C, by setting the band-pass polarization reflection pattern 131, the reflectivity of the display device 10 to the ambient light EB1 can be effectively reduced. Although the reflection of the ambient light EB2 with wavelengths in the aforementioned first wavelength range cannot be completely suppressed, since the ambient light EB2 will undergo two reflections in the first electrode layer E1 in the display device 10, resulting in substantial light energy loss, the reflection of the ambient light EB2 can still produce a substantial inhibitory effect. That is to say, the above configuration method can reduce the overall reflectivity of the display device 10 to the external ambient light, which helps to improve the display quality of the display device 10 (such as the dark state surface or display contrast).

[0041] In addition, although a general display device can achieve the inhibitory effect on the reflection of external ambient light only by using the structure of a polarizing layer and a quarter-wave plate, it also causes obvious light energy loss of the light from the internal light-emitting element (such as causing a display brightness attenuation of more than 50%). Therefore, the setting of the band-pass polarization reflection pattern 131 in this embodiment can not only reduce the overall reflectivity of the display device 10 to the external ambient light, but also avoid the light energy loss of the internal display light (such as the light LB1) due to the setting of the polarizing layer 110 and the quarter-wave plate 120 in the display device 10. In other words, the light energy utilization rate and display quality of the display device 10 can be improved simultaneously.

[0042] Please refer to Figure 2 , in this embodiment, the band-pass polarization reflection layer 130 includes, for example, a substrate SUB1 and a cholesteric liquid crystal layer LCL. The cholesteric liquid crystal layer LCL is disposed on the substrate SUB1 and has a plurality of liquid crystal molecules LC. These liquid crystal molecules LC are, for example, arranged in a twisted manner with a pitch P on the substrate SUB1. It should be particularly noted that the product of the average refractive index of the cholesteric liquid crystal layer LCL and the pitch P is equal to the peak value of the reflection wavelength. That is to say, in order to correspond to the main emission wavelengths of different light-emitting structures, the pitches P of the cholesteric liquid crystal layers LCL of the band-pass polarization reflection pattern 131, the band-pass polarization reflection pattern 132, and the band-pass polarization reflection pattern 133 are all different from each other.

[0043] Furthermore, the band-pass polarization reflection layer 130 may further selectively include an alignment layer AL1, and the alignment layer AL1 is disposed between the cholesteric liquid crystal layer LCL and the substrate SUB1. Therefore, the liquid crystal molecules LC of the cholesteric liquid crystal layer LCL adjacent to the alignment layer are generally arranged in the alignment direction, and the angle between the axial direction of the molecular long axis n (or optical axis) and the film surface of the alignment layer (such as an angle close to 0 degrees) is generally the same.

[0044] However, the present invention is not limited thereto. As Figure 3AAs shown, in other embodiments, an alignment layer may not be provided on the substrate of the band-pass polarizing reflection layer 130A. Therefore, the diversity of the included angle between the axial direction of the optical axis of the liquid crystal molecules LC in different regions of the cholesteric liquid crystal layer LCL-A and the substrate surface can be increased. For example, the included angle θ1 between the molecular major axis n1 of some liquid crystal molecules LC and the surface SUB1s of the substrate SUB1 is substantially different from the included angle θ2 between the molecular major axis n2 of another part of the liquid crystal molecules LC and the surface SUB1s of the substrate SUB1. That is, the inclination angles of the molecular major axes of the liquid crystal molecules LC in multiple regions of the cholesteric liquid crystal layer LCL-A with respect to the substrate SUB1 can be different from each other. Accordingly, the change in the reflectance of the display device to external ambient light at different viewing angles can be suppressed. In an embodiment of the present invention, if the bonding force between the substrate and the cholesteric liquid crystal layer is weak, the substrate can also be removed to reduce the thickness.

[0045] In another embodiment, the band-pass polarizing reflection layer 130B may further selectively include a plurality of surface microstructures MS, and these surface microstructures MS are disposed on the substrate SUB1, for example, disposed between the substrate SUB1 and the cholesteric liquid crystal layer LCL-A, as Figure 3B shown. By providing these surface microstructures MS, the inclination relationship between the molecular major axes of the multiple liquid crystal molecules LC of the cholesteric liquid crystal layer LCL-A and the substrate can be changed more orderly. For example, the appearance or arrangement pitch of these surface microstructures MS can be adjusted to control the reflectance of the display device to external ambient light at different viewing angles.

[0046] Some other embodiments will be listed below to illustrate the present disclosure in detail. The same components will be labeled with the same symbols, and the description of the same technical content will be omitted. For the omitted part, please refer to the foregoing embodiments and will not be repeated hereinafter.

[0047] Figure 4 is a cross-sectional schematic view of a display device according to a second embodiment of the present invention. Please refer to Figure 4 , the difference between the display device 10A of this embodiment and the Figure 1A display device 10 lies in: the configuration methods of the band-pass polarizing reflection layer and the polarizing layer are different. Specifically, the band-pass polarizing reflection layer 130A of the display device 10A only has a plurality of band-pass polarizing reflection patterns 131. That is, the band-pass polarizing reflection layer 130A does not have the band-pass polarizing reflection patterns 132 and 133 that overlap the light-emitting structure ES2 and the light-emitting structure ES3 as in Figure 1A .

[0048] On the other hand, the polarizing layer 110A of this embodiment may have a plurality of openings 110OP overlapping the plurality of light-emitting structures ES2 and the plurality of light-emitting structures ES3, and a plurality of band-pass polarizing patterns are provided in these openings 110OP. For example, a band-pass polarizing pattern 110P1 is provided in the opening 110OP overlapping the light-emitting structure ES2, and a band-pass polarizing pattern 110P2 is provided in the opening 110OP overlapping the light-emitting structure ES3. The absorption axes (not shown) of these band-pass polarizing patterns and the absorption axis AX of the polarizing layer 110A are parallel or perpendicular.

[0049] For example, in this embodiment, the polarization effect of the band-pass polarizing pattern 110P1 on the light with a wavelength in the aforementioned second wavelength range is less obvious. Therefore, the maximum transmittance of the band-pass polarizing pattern 110P1 for the light with a wavelength in the aforementioned second wavelength range can be greater than 45%, even more than 70%. On the contrary, the polarization effect of the band-pass polarizing pattern 110P1 on the light with a wavelength in the visible light range and outside the aforementioned second wavelength range is significant. More specifically, the average transmittance of the band-pass polarizing pattern 110P1 for the light with a wavelength outside the second wavelength range and a polarization direction parallel to the absorption axis AX of the polarizing layer 110A can be less than 20%.

[0050] Since the effect of the band-pass polarizing pattern 110P2 on the light with a wavelength within or outside the third wavelength range is similar to the effect of the band-pass polarizing pattern 110P1 on the light with a wavelength within or outside the second wavelength range, it will not be elaborated here.

[0051] It should be particularly noted that the display device 10A of this embodiment utilizes the above characteristics of the band-pass polarizing pattern to replace Figure 1A part of the band-pass polarizing reflection pattern in, and can also obtain technical effects similar to those of the band-pass polarizing reflection pattern. For example, in addition to reducing the overall reflectance of the display device 10A to external ambient light, it can also avoid the loss of light energy of the internal display light due to the setting of the polarizing layer 110A and the quarter-wave plate 120. In other words, the light energy utilization rate and display quality (such as dark state performance or display contrast) of the display device 10A can be improved simultaneously.

[0052] Figure 5 is a cross-sectional schematic view of a display device according to a third embodiment of the present invention. Please refer to Figure 5 In this embodiment, the display device 10B is the same as Figure 1AThe difference of the display device 10 is that: the polarizing layer 110B in this embodiment is an unpartitioned band-pass polarizing film, and this band-pass polarizing film has an absorption axis AX" parallel to the direction X. That is, the band-pass polarizing film overlaps all the light-emitting structures of the light-emitting layer EML at the same time. On the other hand, the band-pass polarizing reflective layer 130A in this embodiment only has a plurality of band-pass polarizing reflective patterns 131. That is, the band-pass polarizing reflective layer 130A does not have, as in Figure 1A the band-pass polarizing reflective patterns 132 and 133 that overlap the light-emitting structure ES2 and the light-emitting structure ES3.

[0053] For example, in this embodiment, the polarizing layer 110B (i.e., the band-pass polarizing film) has a less obvious polarization effect on the light with a wavelength in the aforementioned second wavelength range or the third wavelength range. Therefore, the maximum transmittance of the polarizing layer 110B for the light with a wavelength in the aforementioned second wavelength range or the third wavelength range can be greater than 45%, even more than 70%. That is to say, the polarizing layer 110B does not significantly absorb the light from the light-emitting structure ES2 and the light-emitting structure ES3.

[0054] On the contrary, the polarizing layer 110B has a more obvious polarization effect on the light with a wavelength in the visible light range and outside the aforementioned second wavelength range and the third wavelength range. More specifically, the average transmittance of the polarizing layer 110B for the light with a wavelength outside the second wavelength range and the third wavelength range and a polarization direction parallel to the absorption axis AX" of the polarizing layer 110B (such as the light in the first wavelength range) can be less than 20%. It should be noted that the light from the light-emitting structure ES1 forms, after passing through the band-pass polarizing reflective pattern 131, light with a first circular polarization state CP1 as in Figure 1A . After this light passes through the quarter-wave plate 120, its polarization state changes from the first circular polarization state CP1 to a first linear polarization state LP1 as in Figure 1A . Therefore, the light from the light-emitting structure ES1 can also pass through the polarizing layer 110B.

[0055] Since the absorption effect (i.e., the polarization effect) of the polarizing layer 110B in this embodiment on the external ambient light with a wavelength in the second wavelength range or the third wavelength range is less obvious, the reflection suppression effect on the external ambient light in these wavelength ranges is poor. However, compared with Figure 4 the display device 10A, the polarizing layer 110B in this embodiment is integrally distributed on the light-emitting layer EML, so it can have a simpler manufacturing process.

[0056] Figure 6 is a cross-sectional schematic view of a display device according to the fourth embodiment of the present invention. Figure 7 is Figure 6 a graph of the reflectivity of the band-pass polarizing reflective layer against wavelength.Figure 8 is Figure 6 A graph of the optical power against wavelength of the display device of Figure 8 and the display device of a comparative example at different light emission wavelengths. Figure 9 is the ambient light and the light power against wavelength of the light reflected by the display device of Figure 8 after passing through Figure 6 the display device.

[0057] Figure 10 is Figure 6 A graph of the ambient light reflectivity of the display device of Figure 10 against the reflectivity of its reflective electrode layer.

[0058] Figure 11 is Figure 7 A graph of the reflectivity against wavelength of another modified embodiment of the band-pass polarizing reflection layer of Figure 11 .

[0059] Please refer to Figure 6 In this embodiment, the difference between the display device 10C of this embodiment and the display device 10 of Figure 1A is that the setting method of the band-pass polarizing reflection layer is different. Specifically, the band-pass polarizing reflection layer 130C of the display device 10C may include a first band-pass polarizing reflection layer 130L1 (band-pass polarizing reflection pattern), a second band-pass polarizing reflection layer 130L2, and a third band-pass polarizing reflection layer 130L3.

[0060] In this embodiment, since the optical characteristics of the first band-pass polarizing reflection layer 130L1, the second band-pass polarizing reflection layer 130L2, and the third band-pass polarizing reflection layer 130L3 are respectively similar to the band-pass polarizing reflection patterns 131, 132, and 133 in Figure 1A , for a detailed description, please refer to the relevant paragraphs of the foregoing embodiment, and will not be elaborated herein.

[0061] Compared with the band-pass polarizing reflection layer 130 of Figure 1A , in this embodiment, the band-pass polarizing reflection layer 130C distributed over the entire surface is used to replace the band-pass polarizing reflection pattern of Figure 1A , that is, the first band-pass polarizing reflection layer 130L1 overlaps these light-emitting structures ES1 and these light-emitting structures ES2, and the first band-pass polarizing reflection layer 130L1 and the second band-pass polarizing reflection layer 130L2 overlap each other. Therefore, there is no need to correspondingly adjust the structural design of the band-pass polarizing reflection layer according to different light-emitting structure designs, which helps to simplify the design and manufacturing process of the display device 10C.

[0062] It is worth mentioning that Figure 6The polarizing layer 110 can also use a band-pass polarizing film. For example, when the second band-pass polarization reflection layer 130L2 can reflect the light of the light-emitting structure ES2, if the polarization of the light of the light-emitting structure ES2 by the band-pass polarizing film is not obvious, the reflectivity of the second band-pass polarization reflection layer in the second wavelength range can be less than 20%. Specifically, the light-emitting structure ES2 of the display device 10C has a main emission wavelength, and the main emission wavelength of the light-emitting structure ES2 is different from the main emission wavelength of the light-emitting structure ES1. The first band-pass polarization reflection layer 130L1 (band-pass polarization reflection pattern) overlaps the light-emitting structure ES1 and the light-emitting structure ES2. The polarizing layer 110 is a band-pass polarizing film, and the polarizing layer 110 also overlaps the light-emitting structure ES1 and the light-emitting structure ES2, and has an absorption axis AX. The maximum transmittance of the polarizing layer 110 for light with a wavelength in the second wavelength range is greater than 45%. The second wavelength range is the main emission wavelength of the light-emitting structure ES2 ± 10 nm. The average transmittance of the polarizing layer 110 for light with a wavelength outside the second wavelength range and a polarization direction parallel to the absorption axis AX is less than 20%.

[0063] In another embodiment, the band-pass polarizing film can replace one of the band-pass polarization reflection layers. For example, when the second band-pass polarization reflection layer 130L2 can reflect the light of the light-emitting structure ES2, if the polarization of the light of ES2 by the band-pass polarizing film is not obvious, the second band-pass polarization reflection layer 130L2 can be replaced, which can further reduce the cost and thickness.

[0064] Please also refer to Figures 6 to 8 , in this embodiment, the reflection spectrum of the band-pass polarization reflection layer 130C includes a waveform WF1 covering the main emission wavelength of the light-emitting structure ES1, a waveform WF2 covering the main emission wavelength of the light-emitting structure ES2, and a waveform WF3 covering the main emission wavelength of the light-emitting structure ES3. In order to obtain a technical effect similar to that of Figure 1A the embodiment, that is, to improve the light energy utilization rate and display quality (such as dark state performance or display contrast) of the display device 10C, the full width at half maximum (FWHM) of each of the above waveforms WF1, WF2, and WF3 should be less than 100 nm, preferably less than 50 nm. For example, as Figure 7 shown, the full width at half maximum FWHM1 of the waveform WF1 is about 54 nm, the full width at half maximum FWHM2 of the waveform WF2 is about 46 nm, and the full width at half maximum FWHM3 of the waveform WF3 is about 40 nm.

[0065] On the other hand, the difference between any two of the main emission wavelength PW1 of the light-emitting structure ES1, the main emission wavelength PW2 of the light-emitting structure ES2, and the main emission wavelength PW3 of the light-emitting structure ES3 should be greater than 30 nm (as Figure 8As shown. For example, in this embodiment, the main emission wavelengths of the light-emitting structures ES1, ES2, and ES3 are 623 nm, 525 nm, and 460 nm, respectively.

[0066] Figure 8 FIG. shows the comparison of the light output power of the display device 10C of this embodiment and that of a display device of a comparative example within different wavelength ranges, where curves C1, C2, and C3 respectively represent the distribution of the light output power with respect to wavelength of the display device of the comparative example (without the band-pass polarizing reflective layer 130C) within the first wavelength range, the second wavelength range, and the third wavelength range, and curves C4, C5, and C6 respectively represent the distribution of the light output power with respect to wavelength of the display device 10C of this embodiment within the first wavelength range, the second wavelength range, and the third wavelength range. From Figure 8 it can be seen that within any wavelength range, the display device 10C of this embodiment has significantly better light output power due to the presence of the band-pass polarizing reflective layer 130C.

[0067] On the other hand, Figure 9 Curve D1 in shows the distribution of the light power of a D65 ambient light with respect to wavelength, and curve D2 shows the reflected light spectrum obtained after irradiating the display device 10C of this embodiment with this D65 ambient light. From Figure 9 it can be seen that the brightness attenuation amplitude of the D65 ambient light after being reflected by the display device 10C can reach 90%.

[0068] Furthermore, in this embodiment, the reflectivity of the first electrode layer E1 can be between 30% and 80%. Since part of the ambient light will experience two reflections from the first electrode layer E1 within the display device (as Figure 1C shown), reducing the reflectivity of the first electrode layer E1 can effectively suppress the overall reflectivity of the display device to the ambient light. As Figure 10 shown, the reflectivity of the display device 10C to the ambient light is positively correlated with the reflectivity of the first electrode layer E1.

[0069] In addition, please refer to Figure 2 and Figure 6 simultaneously. In this embodiment, the reflection bandwidth of the band-pass polarizing reflective layer 130C is positively correlated with the refractive index anisotropy and the pitch P of the cholesteric liquid crystal layer LCL (as Figure 2 shown). Therefore, by adjusting the above characteristics of the cholesteric liquid crystal layer LCL (such as reducing the pitch), a narrower reflection bandwidth can be obtained. As Figure 11As shown, for the adjusted band-pass polarizing reflection layer, the full width at half maximum (FWHM) of waveform WF1” is approximately 42 nm, the FWHM of waveform WF2” is approximately 35 nm, and the FWHM of waveform WF3” is approximately 31 nm. Accordingly, the light output power of the display device can be further improved. For example, the brightness gain can be increased by approximately 40% compared to the aforementioned comparative example (i.e., the display device without the band-pass polarizing reflection layer), and the reflectivity of the display device to D65 ambient light can be reduced to 10%.

[0070] Figure 12 is a schematic cross-sectional view of a display device according to a fifth embodiment of the present invention. Please refer to Figure 12 , the difference between the display device 20 of this embodiment and Figure 6 the display device 10C is that: the display device 20 further includes an absorbing layer ABL, which is disposed between a plurality of light-emitting structures of the light-emitting layer EML and is located between the band-pass polarizing reflection layer 130C and the circuit board 100. The material of the absorbing layer ABL includes, for example, a black resin material or a black metal. Through the absorption characteristics of the absorbing layer ABL in the visible light band, the overall reflectivity of the display device 20 to external ambient light can be further reduced.

[0071] Figure 13 is a schematic cross-sectional view of a display device according to a sixth embodiment of the present invention. Please refer to Figure 13 , the difference between the display device 20A of this embodiment and Figure 12 the display device 20 is that: the display device 20A further includes a dimming layer 160 disposed between the band-pass polarizing reflection layer 130C and the absorbing layer ABL. It should be particularly noted that the dimming layer 160 of the display device 20A is disposed between the second band-pass polarizing reflection layer 130L2 and the third band-pass polarizing reflection layer 130L3. The material of the dimming layer 160 includes, for example, an optical clear adhesive (OCA) or a hardened optical clear resin (OCR).

[0072] In this embodiment, the reflectivity of the first band-pass polarizing reflection layer 130L1 to light with wavelengths in the first wavelength range is greater than 20%, and the first wavelength range is, for example, the red light wavelength range (e.g., 610 nm to 630 nm). The reflectivity of the second band-pass polarizing reflection layer 130L2 to light with wavelengths in the second wavelength range is greater than 20%, and the second wavelength range is, for example, the green light wavelength range (e.g., 515 nm to 535 nm). The reflectivity of the third band-pass polarizing reflection layer 130L3 to light with wavelengths in the third wavelength range is greater than 20%, and the third wavelength range is, for example, the blue light wavelength range (e.g., 450 nm to 470 nm).

[0073] For example, in the present embodiment, a first band-pass polarization reflection layer 130L1 adapted to reflect red light, a second band-pass polarization reflection layer 130L2 adapted to reflect green light, and a third band-pass polarization reflection layer 130L3 adapted to reflect blue light are sequentially disposed on the light-emitting layer EML. Therefore, by disposing the light-dimming layer 160 between the second band-pass polarization reflection layer 130L2 and the third band-pass polarization reflection layer 130L3, the chance of blue light being incident on the light-absorbing layer ABL after being reflected by the third band-pass polarization reflection layer 130L3 can be increased, thereby reducing the problem that the display screen of the display device 20A appears blue when viewed at an oblique angle. From another perspective, through the above-described configuration relationship between the light-absorbing layer ABL and the light-dimming layer 160, the light-emitting angle range of blue light can be reduced.

[0074] Furthermore, the light-dimming layer 160 can also be selectively doped with a material that can absorb blue light. Since the optical path of obliquely incident blue light in the light-dimming layer 160 is longer, the absorption effect is higher than that of directly incident blue light. Therefore, the problem of the display screen appearing blue can be further suppressed, and the absorption effect of the display device on external blue light can be improved.

[0075] Figure 14 is a cross-sectional schematic view of a display device according to a seventh embodiment of the present invention. Please refer to Figure 14 , the difference between the display device 20B of the present embodiment and the Figure 6 display device 10C mainly lies in: the stacked structure of the band-pass polarization reflection layer is different. Specifically, the band-pass polarization reflection layer 130D of the display device 20B further includes an auxiliary band-pass polarization reflection layer 130L4 and an auxiliary band-pass polarization reflection layer 130L5 disposed between the first band-pass polarization reflection layer 130L1 and the quarter-wave plate 120 (or the polarization layer 110). These auxiliary band-pass polarization reflection layers overlap multiple light-emitting structures of the light-emitting layer EML, and the auxiliary band-pass polarization reflection layer 130L4 is located between the third band-pass polarization reflection layer 130L3 and the auxiliary band-pass polarization reflection layer 130L5. On the other hand, the setting order of the first band-pass polarization reflection layer 130L1, the second band-pass polarization reflection layer 130L2, and the third band-pass polarization reflection layer 130L3 in the present embodiment is opposite to that of the Figure 6 display device 10C.

[0076] It should be noted in particular that the auxiliary band-pass polarization reflection layer has at least one auxiliary reflection peak for wavelengths within the auxiliary wavelength range, and the reflectivity of light within ±10 nm of the auxiliary reflection peak is greater than 10%, and the auxiliary wavelength range falls between 650 nm and 770 nm. For example, in this embodiment, the auxiliary wavelength range of the light that the auxiliary band-pass polarization reflection layer 130L4 is suitable for reflecting is, for example, in the range of 670 nm to 690 nm (i.e., deep red light), and the auxiliary wavelength range of the light that the auxiliary band-pass polarization reflection layer 130L5 is suitable for reflecting is, for example, in the range of 730 nm to 750 nm (i.e., near-infrared light), but not limited thereto. More specifically, the difference between the main reflection wavelength of the auxiliary band-pass polarization reflection layer 130L4 and the main reflection wavelength of the first band-pass polarization reflection layer 130L1 (such as 620 nm) is greater than or equal to 60 nm, and the difference between the main reflection wavelength of the auxiliary band-pass polarization reflection layer 130L5 and the main reflection wavelength of the auxiliary band-pass polarization reflection layer 130L4 is greater than or equal to 60 nm.

[0077] Since the reflection spectrum of the band-pass polarization reflection layer 130D changes with different incident angles of light. For example, the main wavelength of the light suitable for being reflected will decrease as the incident angle increases. That is, the main frequency of the reflection band of the band-pass polarization reflection layer 130D will exhibit a blue shift.

[0078] For example, the blue light that is incident on the third band-pass polarization reflection layer 130L3 non-normally and cannot be effectively reflected will be reflected by the second band-pass polarization reflection layer 130L2. The green light that is incident on the second band-pass polarization reflection layer 130L2 non-normally and cannot be effectively reflected will be reflected by the first band-pass polarization reflection layer 130L1. The red light that is incident on the first band-pass polarization reflection layer 130L1 non-normally and cannot be effectively reflected will be reflected by the auxiliary band-pass polarization reflection layer 130L4. The deep red light that is incident on the auxiliary band-pass polarization reflection layer 130L4 non-normally and cannot be effectively reflected will be reflected by the auxiliary band-pass polarization reflection layer 130L5. To ensure that the display does not have color deviation, in the present invention, at the same angle, the difference in reflectivity of different wavelengths is less than 5%, and the preferred range is less than 2%. For example, when the red light reflectivity is 10% at an elevation angle of 60 degrees, the reflectivity of blue light and green light is within 5% to 15%, and the preferred range is within 8% to 12%.

[0079] Therefore, through the above laminated relationship of the band-pass polarization reflection layer 130D, the color deviation problem of the display screen when the display device 20B is viewed at a large viewing angle can be suppressed, which helps to improve its display quality.

[0080] Figure 15 It is a cross-sectional schematic diagram of a display device according to the eighth embodiment of the present invention. Please refer to Figure 15 , the display device 20C of this embodiment and Figure 12The difference between the display device 20 is that the configuration of the light-absorbing layer is different. Specifically, the light-absorbing layer ABL-A of the display device 20C has a plurality of light-absorbing patterns ABP1, a plurality of light-absorbing patterns ABP2, and a plurality of light-absorbing patterns ABP3, and the light-absorbing patterns ABP1, ABP2, and ABP3 can be alternately arranged along the direction X.

[0081] For example, in this embodiment, the light-absorbing patterns ABP1, ABP2, and ABP3 are respectively arranged around the light-emitting structures ES1, ES2, and ES3 of the light-emitting layer EML, but it is not limited thereto. In other embodiments, the light-absorbing patterns of the light-absorbing layer can also be arranged corresponding to the light-emitting structures in other implementation manners.

[0082] It should be particularly noted that, corresponding to the light-emitting structures with different main emission wavelengths, the light-absorbing patterns of the light-absorbing layer ABL-A have different heights. For example, the height H1 of the light-absorbing pattern ABP1 arranged corresponding to the light-emitting structure ES1 can be less than the height H2 of the light-absorbing pattern ABP2 arranged corresponding to the light-emitting structure ES2, and the height H2 of the light-absorbing pattern ABP2 can be less than the height H3 of the light-absorbing pattern ABP3 arranged corresponding to the light-emitting structure ES3. The height here is, for example, the thickness of the light-absorbing pattern along the direction perpendicular to the circuit board 100 (such as the direction Z).

[0083] As in Figure 12 the display device 20, since the third band-pass polarization reflection layer 130L3 is farther from the light-emitting layer EML than other band-pass polarization reflection layers, therefore, setting the height H3 of the light-absorbing pattern ABP3 to be higher than that of other light-absorbing patterns can effectively block the blue light incident on the third band-pass polarization reflection layer 130L3 at a large angle, thereby reducing the problem that the display screen of the display device 20C is bluish when viewed at an oblique angle.

[0084] It should be noted that the height size relationship of the light-absorbing patterns of the light-absorbing layer ABL-A corresponding to the light-emitting structures with different main emission wavelengths is adjusted according to the stacking order of the plurality of band-pass polarization reflection layers corresponding to different reflection main wavelengths. The present invention is not limited by the content disclosed in the drawings. For example, when the second band-pass polarization reflection layer 130L2 is changed to be disposed between the third band-pass polarization reflection layer 130L3 and the quarter-wave plate 120, the height of the light-absorbing pattern arranged corresponding to the light-emitting structure ES2 can also be greater than the heights of the two light-absorbing patterns arranged corresponding to the light-emitting structures ES1 and ES3 respectively.

[0085] In summary, in the display device according to an embodiment of the present invention, a band-pass polarization reflection layer is provided between the quarter-wave plate and the light-emitting layer and overlaps the light-emitting structure. The first band-pass polarization reflection pattern of this band-pass polarization reflection layer has a reflectivity greater than 20% for light within a specific wavelength range. Accordingly, the overall reflectivity of the display device to external ambient light can be effectively reduced, and at the same time, the light energy loss of the polarization layer to the internal display light can be reduced, thereby improving the light energy utilization rate and dark state performance of the display device.

[0086] As described above, the above are only the preferred embodiments of the present invention, and the scope of implementation of the present invention cannot be limited thereby. That is, all simple equivalent changes and modifications made according to the claims of the present invention and the content of the invention still fall within the scope covered by the patent of the present invention. In addition, any embodiment or claim of the present invention does not have to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and the invention name are only used to assist in the retrieval of patent documents and do not limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or claims are only used to name elements or distinguish different embodiments or scopes, and do not limit the upper or lower limits of the number of elements. Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to what is defined by the appended claims.

[0087] Description of Reference Numerals

[0088] 10, 10A, 10B, 10C, 20, 20A, 20B, 20C: Display device

[0089] 100: Circuit board

[0090] 110, 110A, 110B: Polarization layer

[0091] 110OP: Opening

[0092] 110P1, 110P2: Band-pass polarization pattern

[0093] 120: Quarter-wave plate

[0094] 130, 130A, 130B, 130C, 130D: Band-pass polarization reflection layer

[0095] 130L1: First band-pass polarization reflection layer

[0096] 130L2: Second band-pass polarization reflection layer

[0097] 130L3: Third band-pass polarization reflection layer

[0098] 130L4, 130L5: Auxiliary band-pass polarizing reflection layer

[0099] 131, 132, 133: Band-pass polarizing reflection pattern

[0100] 140: Encapsulation layer

[0101] 150: Translucent adhesive layer

[0102] 160: Dimming layer

[0103] ABL, ABL-A: Absorbing layer

[0104] ABP1, ABP2, ABP3: Absorbing pattern

[0105] AL1: Alignment layer

[0106] AX, AX”: Absorbing axis

[0107] CP1: First circular polarization state

[0108] CP2: Second circular polarization state

[0109] E1: First electrode layer

[0110] E2: Second electrode layer

[0111] EB1, EB2: Ambient light

[0112] EML: Emitting layer

[0113] ES1, ES2, ES3: Emitting structure

[0114] FWHM1, FWHM2, FWHM3, FWHM1”, FWHM2”, FWHM3”: Full width at half maximum

[0115] H1, H2, H3: Height

[0116] LB1, LB1a, LB1b: Light ray

[0117] LC: Liquid crystal molecule

[0118] LCL, LCL-A: Cholesteric liquid crystal layer

[0119] LP1: First linear polarization state

[0120] LP2: Second linear polarization state

[0121] MS: Surface microstructure

[0122] n, n1, n2: Molecular major axis

[0123] P: Pitch

[0124] PW1, PW2, PW3: Main emission wavelength

[0125] SUB1: Substrate

[0126] SUB1s: Surface

[0127] WF1, WF2, WF3, WF1”, WF2”, WF3”: Waveform

[0128] X, Y, Z: Direction

[0129] θ1, θ2: Included angle.

Claims

1. A display device, characterized in that, The display device includes: A circuit board; A light-emitting layer disposed on the circuit board and having a plurality of light-emitting structures. The plurality of light-emitting structures are electrically connected to the circuit board. The plurality of light-emitting structures include a plurality of first light-emitting structures and a plurality of second light-emitting structures. The plurality of first light-emitting structures have a first main emission wavelength, and the plurality of second light-emitting structures have a second main emission wavelength, and the second main emission wavelength is different from the first main emission wavelength; A polarizing layer overlapped on the light-emitting layer and located on a side of the light-emitting layer away from the circuit board; A quarter-wave plate disposed between the polarizing layer and the light-emitting layer and overlapped on the light-emitting layer and the polarizing layer; and A band-pass polarizing reflection layer disposed between the quarter-wave plate and the light-emitting layer. The band-pass polarizing reflection layer includes a first band-pass polarizing reflection pattern that overlaps on the plurality of first light-emitting structures. The reflectivity of the first band-pass polarizing reflection pattern for light with a wavelength within a first wavelength range is greater than 20%. The first wavelength range is the first main emission wavelength ± 10 nm, wherein the polarizing layer overlaps on the plurality of first light-emitting structures and the plurality of second light-emitting structures and has an absorption axis. The maximum transmittance of the polarizing layer for light with a wavelength within a second wavelength range is greater than 70%. The second wavelength range is the second main emission wavelength ± 10 nm. The average transmittance of the polarizing layer for light with a wavelength outside the second wavelength range and a polarization direction parallel to the absorption axis is less than 20%.

2. The display device according to claim 1, characterized in that, The band-pass polarizing reflection layer includes a cholesteric liquid crystal layer having a plurality of liquid crystal molecules, and the plurality of liquid crystal molecules are arranged in a twist with a pitch.

3. The display device according to claim 2, wherein, The band-pass polarizing reflection layer further includes: A substrate; The cholesteric liquid crystal layer is disposed on the substrate; and A plurality of surface microstructures disposed between the substrate and the cholesteric liquid crystal layer, wherein the long axes of the plurality of liquid crystal molecules overlapping on the plurality of surface microstructures have different tilt angles with respect to the substrate.

4. The display device according to claim 1, wherein The band-pass polarizing reflection layer further includes a second band-pass polarizing reflection pattern that overlaps on the plurality of second light-emitting structures. The reflectivity of the second band-pass polarizing reflection pattern for light with a wavelength within a second wavelength range is greater than 20%. The second wavelength range is the second main emission wavelength ± 10 nm.

5. The display device according to claim 1, wherein The band-pass polarizing reflection layer further includes a second band-pass polarizing reflection layer. The first band-pass polarizing reflection pattern overlaps on the plurality of first light-emitting structures and the plurality of second light-emitting structures. The first band-pass polarizing reflection pattern and the second band-pass polarizing reflection layer overlap each other. The reflectivity of the second band-pass polarizing reflection layer for light with a wavelength within a second wavelength range is greater than 20%. The second wavelength range is the second main emission wavelength ± 10 nm.

6. The display device according to claim 5, wherein The difference between the first main emission wavelength and the second main emission wavelength is greater than 30 nm.

7. The display device according to claim 5, wherein The reflection spectrum of the bandpass polarized reflection layer includes a first waveform covering the first main light-emitting wavelength and a second waveform covering the second main light-emitting wavelength, and the half-width at half maximum of each of the first waveform and the second waveform is less than 50 nm.

8. The display device according to claim 1, characterized in that The first band-pass polarized reflective pattern overlaps the plurality of first light-emitting structures and the plurality of second light-emitting structures, and the polarizing layer is a band-pass polarizing film.

9. The display device according to claim 1, wherein, The display device further includes: The light absorbing layer is arranged between the plurality of light emitting structures and located between the bandpass polarizing reflective layer and the circuit substrate.

10. The display device according to claim 9, wherein The display device further includes: The dimming layer is arranged between the bandpass polarized reflective layer and the light absorbing layer.

11. The display device according to claim 9, wherein The light absorption layer has a plurality of first light absorption patterns corresponding to the plurality of first light-emitting structures and a plurality of second light absorption patterns corresponding to the plurality of second light-emitting structures, the second main light-emitting wavelength is greater than the first main light-emitting wavelength, and a first height of each of the plurality of first light absorption patterns along a direction perpendicular to the circuit substrate is different from a second height of each of the plurality of second light absorption patterns along the direction.

12. The display device according to claim 5, characterized in that, The bandpass polarized reflective layer also includes an auxiliary bandpass polarized reflective layer, the auxiliary bandpass polarized reflective layer overlaps the multiple first light-emitting structures and the multiple second light-emitting structures, and the auxiliary bandpass polarized reflective layer is located between the polarizing layer and the second bandpass polarized reflective layer, the auxiliary bandpass polarized reflective layer has at least one auxiliary reflection peak for a wavelength within an auxiliary wavelength range, the reflectivity of light within ±10nm of the at least one auxiliary reflection peak is greater than 10%, and the auxiliary wavelength range falls within the range of 650nm to 770nm.

13. A display device, characterized in that, The display device comprises: Circuit board; a light-emitting layer, disposed on the circuit substrate and having a plurality of light-emitting structures, the plurality of light-emitting structures being electrically connected to the circuit substrate, the plurality of light-emitting structures comprising a plurality of first light-emitting structures and a plurality of second light-emitting structures, the plurality of first light-emitting structures having a first main light-emitting wavelength, and the plurality of second light-emitting structures having a second main light-emitting wavelength; a polarizing layer, overlapping the light-emitting layer and located on a side of the light-emitting layer away from the circuit substrate; a quarter wave plate, disposed between the polarizing layer and the light emitting layer, and overlapping the light emitting layer and the polarizing layer; and a bandpass polarized reflective layer, arranged between the quarter wave plate and the light-emitting layer, the bandpass polarized reflective layer comprising a first bandpass polarized reflective pattern, the first bandpass polarized reflective pattern overlapping the plurality of first light-emitting structures, wherein the first bandpass polarized reflective pattern has a reflectivity greater than 20% for light within a first wavelength range, the first wavelength range being ±10 nm of the first main light-emitting wavelength, Wherein, the polarizing layer has a plurality of openings overlapping the plurality of second light-emitting structures, a plurality of band-pass polarizing patterns are provided in the plurality of openings, the plurality of band-pass polarizing patterns and the polarizing layer have an absorption axis, and the maximum transmittance for light with a wavelength in the second wavelength range is greater than 70%, the second wavelength range is the second main emission wavelength ± 10 nm and within the visible light range, and the average transmittance of the plurality of band-pass polarizing patterns for light with a wavelength outside the second wavelength range and a polarization direction parallel to the absorption axis is less than 20%.

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