Display device

Abstract

A display device includes a circuit substrate, a light-emitting layer, a quarter-wave plate, and a band-pass polarizing layer. The light-emitting layer is disposed on the circuit substrate and has a plurality of light-emitting structures. The light-emitting structures are electrically connected to the circuit substrate and include a plurality of first light-emitting structures. The first light-emitting structures have a first main light-emitting wavelength. The quarter-wave plate overlaps the light-emitting structures of the light-emitting layer. The quarter-wave plate is between the band-pass polarizing layer and the light-emitting layer. The band-pass polarizing layer includes a plurality of first band-pass polarizing patterns. The first band-pass polarizing patterns have a first absorption axis and an average transmittance greater than 50% in a first wavelength range. The first wavelength range is the first main light-emitting wavelength ± 10 nm. The first band-pass polarizing patterns have an average transmittance less than 20% outside the first wavelength range and in a polarization direction parallel to the first absorption axis. The display device provided by the present application can balance the light energy utilization rate and the dark state contrast.

Description

TECHNICAL FIELD

[0001] The present application relates to an electronic device, and more particularly to a display device. BACKGROUND

[0002] In recent years, organic light-emitting diode (OLED) display panels and micro light-emitting diode display panels have gradually gained favor due to their high color saturation, fast response speed, and high-contrast display quality. In order to increase the light extraction efficiency of such self-emitting display panels, the electrode on the side of the light-emitting diode away from the light-emitting surface is mostly a reflective electrode. Since such a reflective electrode reflects external ambient light, when the display panel presents a full-screen black picture or a local dark state, the human eye is likely to perceive the external ambient light reflected by the reflective electrode, resulting in a decrease in display quality or appearance taste.

[0003] To solve the above problems, a technical solution of setting a circular polarizer on the side of the light-emitting surface of the self-emitting display panel is proposed. The setting of the circular polarizer causes the external ambient light passing through to form circularly polarized light with a specific rotation, and this circularly polarized light forms circularly polarized light with an opposite rotation after being reflected by the reflective electrode, and this circularly polarized light with an opposite rotation cannot pass through the circular polarizer. Accordingly, the reflectivity of such self-emitting display panels to external ambient light is reduced. However, such a circular polarizer reduces the overall light extraction of the self-emitting display panel, for example, causing the light extraction brightness to decay by at least 55%. SUMMARY

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

[0005] To achieve one or some or all of the above-mentioned objects, an embodiment of the present application provides a display device. The display device includes a circuit substrate, a light-emitting layer, a quarter-wave plate, and a band-pass polarizing layer. The light-emitting layer is disposed on the circuit substrate and has a plurality of light-emitting structures. The light-emitting structures are disposed on the circuit substrate and are electrically connected to the circuit substrate. The light-emitting structures include a plurality of first light-emitting structures. The first light-emitting structures have a first main light-emitting wavelength. The quarter-wave plate is disposed on the light-emitting structures of the light-emitting layer. The band-pass polarizing layer is disposed on the quarter-wave plate. The quarter-wave plate is located between the band-pass polarizing layer and the light-emitting layer. The band-pass polarizing layer includes a plurality of first band-pass polarizing patterns. The first band-pass polarizing patterns have a first absorption axis and an average transmittance of greater than 50% for light having a wavelength in a first wavelength range. The first wavelength range is the first main light-emitting wavelength ± 10 nm, and the first band-pass polarizing patterns have an average transmittance of less than 20% for light having a wavelength outside the first wavelength range and a polarization direction parallel to the first absorption axis in the range of visible light.

[0006] Based on the above, in the display device of an embodiment of the present application, the quarter-wave plate is provided with a band-pass polarizing layer on the side away from the light-emitting layer. The plurality of first band-pass polarizing patterns of the band-pass polarizing layer have an average transmittance of greater than 50% for light in a specific wavelength range, and an average transmittance of less than 20% and a polarizing effect for light in the range of visible light having a wavelength outside the specific wavelength range and a polarization direction parallel to the absorption axis of the first band-pass polarizing pattern. In this way, in addition to increasing the overall light output of the display device, the overall reflectivity of the display device to external ambient light can also be reduced, thereby improving the light energy utilization rate and dark state performance of the display device.

[0007] In order to make the above features and advantages of the present application more obvious and easy to understand, the following specific embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1A and Figure 1B are respectively a cross-sectional schematic view of a display device of a first embodiment of the present application for excitation light and external ambient light.

[0009] Figure 2 is Figure 1A a schematic view of part of the film layers of the display device of

[0010] Figure 3 is Figure 1A a transmittance-wavelength curve of the band-pass polarizing layer of

[0011] Figure 4 is Figure 1A a transmittance-wavelength curve of the combination of the band-pass polarizing layer and the quarter-wave plate of under external ambient light passing through twice.

[0012] Figure 5 yes Figure 1A The transmittance versus wavelength curve of a combination of a bandpass polarizing layer and a quarter-wave plate when light from a D65 light source passes through twice.

[0013] Figure 6 yes Figure 1A The transmittance versus wavelength curves of the combination of the bandpass polarizing layer and the quarter-wave plate, and the circular polarizing plate of the comparative example.

[0014] Figure 7 This is a cross-sectional schematic diagram of a display device according to a second embodiment of the present invention.

[0015] Figure 8 This is a cross-sectional schematic diagram of a display device according to a third embodiment of the present invention.

[0016] Figure 9 yes Figure 8 A schematic diagram of a portion of the film layer of a display device.

[0017] Figure 10 yes Figure 9 A schematic diagram of another modified embodiment of the display device.

[0018] Figure 11 This is a cross-sectional schematic diagram of a display device according to the fourth embodiment of the present invention.

[0019] Figure 12 yes Figure 11 A schematic diagram of a portion of the film layer of a display device. Detailed Implementation

[0020] The foregoing descriptions and other technical contents, features, and effects of this invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms used in the following embodiments, such as up, down, left, right, front, or back, are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0021] Figure 1A and Figure 1B These are cross-sectional schematic diagrams of the display device according to the first embodiment of the present invention regarding the excitation light and the external ambient light. Figure 2 yes Figure 1A A schematic diagram of a portion of the film layer of a display device. Figure 3 yes Figure 1A The transmittance of the bandpass polarizing layer versus wavelength curve. Figure 4 yes Figure 1A The transmittance versus wavelength curve of the combination of bandpass polarizing layer and quarter-wave plate when ambient light passes through twice. Figure 5 yesFigure 1A The transmittance versus wavelength curve of a combination of a bandpass polarizing layer and a quarter-wave plate when light from a D65 light source passes through twice. Figure 6 yes Figure 1A The transmittance versus wavelength curves of the combination of the bandpass polarizing layer and the quarter-wave plate, and the circular polarizing plate of the comparative example.

[0022] Please refer to Figure 1A , Figure 1B and Figure 2 The display device 10 includes a circuit board 100, a light-emitting layer 110, a quarter-wave plate 120, and a bandpass polarizing layer 130. The light-emitting layer 110 is disposed on the circuit board 100. The light-emitting layer 110 has multiple light-emitting structures overlapping on the circuit board 100, and the multiple 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 capable of individually controlling multiple display pixels. Accordingly, the light-emitting layer 110 may include multiple first light-emitting structures ES1, multiple second light-emitting structures ES2, multiple third light-emitting structures ES3, an isolation structure layer 115, a first electrode layer E1, and a second electrode layer E2. The isolation structure layer 115 has multiple openings 115a. These first light-emitting structures ES1, these second light-emitting structures ES2, and these third light-emitting structures ES3 are arranged alternately in sequence along the X direction, and are respectively disposed within these openings 115a. The multiple light-emitting structures arranged along the Y direction are, for example, the same type of light-emitting structure. The openings 115a of the isolation structure layer 115 can define multiple pixel areas PA of the display device 10, and the first light-emitting structures ES1, the second light-emitting structures ES2, and the third light-emitting structures ES3 located within these pixel areas PA can serve as display pixels, but the present invention is not limited thereto. In other embodiments, the display device 10 can be a monochrome grayscale display or a black-and-white grayscale display, that is, the display device 10 can include only one type of light-emitting structure.

[0023] For example, the first, second and third light emitting structures ES1, ES2 and ES3 are adapted to emit excitation light of different primary light emitting wavelengths, such as red light (e.g. light having a primary light emitting wavelength greater than 600 nm), green light (e.g. light having a primary light emitting wavelength between 500 nm and 600 nm) and blue light (e.g. light having a primary light emitting wavelength less than 500 nm), respectively, and the light of different intensities is mixed to achieve the color display effect. That is, the display device 10 of the present embodiment is a self-emitting display, such as an organic light emitting diode (OLED) display, but is not limited thereto. In other embodiments, the display device 10 can also be a micro light emitting diode (micro-LED) display or a mini light emitting diode (mini-LED) display.

[0024] In the present embodiment, the first and second electrode layers E1 and E2 are respectively disposed on opposite sides of the plurality of light emitting structures and electrically connected to the light emitting structures. For example, the first electrode layer E1 is located between the light emitting structures and the circuit substrate 100 and has a plurality of electrode patterns. The electrode patterns are respectively disposed on the light emitting structures (i.e. respectively disposed in the openings 115a) and are respectively electrically connected to a plurality of active elements (not shown) of the circuit substrate 100. The second electrode layer E2 is, for example, a full-area electrode covering the light emitting structures and the isolation structure layer 115. More specifically, the current flowing through the light emitting structures can be individually controlled by the active elements to generate the same or different light emitting intensities in different pixel areas PA.

[0025] 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 material, or a stack of metal material and other conductive material. The second electrode layer E2 is, for example, a light-transmitting electrode layer, and the material of the light-transmitting electrode layer includes metal oxide, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, or other suitable oxide, or a stack of at least two of the above.

[0026] The quarter-wave plate 120 of the display device 10 is arranged to overlap the plurality of light-emitting structures (e.g., the first light-emitting structure ES1, the second light-emitting structure ES2, and the third light-emitting structure ES3) of the light-emitting layer 110 and the band-pass polarizing layer 130, and is located between the band-pass polarizing layer 130 and the light-emitting layer 110. It is worth mentioning that the quarter-wave plate of the present application can be a combination of multiple compensation films, such as a quarter-wave plate and a half-wave plate. In the present embodiment, the band-pass polarizing layer 130 can include a plurality of first polarizing patterns, such as a plurality of band-pass polarizing patterns 131, a plurality of band-pass polarizing patterns 132, and a plurality of band-pass polarizing patterns 133, and the band-pass polarizing patterns 131, the band-pass polarizing patterns 132, and the band-pass polarizing patterns 133 are respectively overlapped with the first light-emitting structure ES1, the second light-emitting structure ES2, and the third light-emitting structure ES3 of the light-emitting layer 110 in the direction Z, but are not limited thereto. That is, the band-pass polarizing patterns 131, the band-pass polarizing patterns 132, and the band-pass polarizing patterns 133 are also alternately arranged along the direction X. It is particularly noted that the display device 10 can also selectively include an encapsulation layer 140 arranged between the light-emitting layer 110 and the quarter-wave plate 120 to protect the light-emitting layer 110, but is not limited thereto.

[0027] Further, in the present embodiment, the band-pass polarizing patterns of the band-pass polarizing layer 130 all have the same axial absorption axis A, and the angle between the axial direction of the absorption axis A and the axial direction of the optical axis n of the quarter-wave plate 120 is 45 degrees, but is not limited thereto. In other embodiments, the absorption axes of the band-pass polarizing patterns can have different axial directions, such as the axial direction of the absorption axes of part of the band-pass polarizing patterns 131 being perpendicular to the axial direction of the absorption axes of another part of the band-pass polarizing patterns 131. It is particularly noted that the average transmittance of the band-pass polarizing patterns to light having a wavelength in a respective specific wavelength range is greater than 50%, more preferably greater than 60%, and the wavelength range is the range of the main light-emitting wavelength of the light-emitting structure corresponding to each band-pass polarizing pattern plus or minus 10 nm (i.e., the main light-emitting wavelength ± 10 nm), but the present application is not limited thereto. In other embodiments, the wavelength range is the range of the main light-emitting wavelength of the light-emitting structure corresponding to each band-pass polarizing pattern plus or minus 20 nm.

[0028] In particular, light from the light-emitting layer 110 and having a wavelength in a specific wavelength range does not substantially exhibit a polarizing property after passing through the band-pass polarizing pattern having the specific wavelength range, i.e., the band-pass polarizing pattern does not absorb light having a wavelength in the specific wavelength range. On the other hand, in the range of visible light (e.g., wavelengths of 400 nm to 700 nm), the average transmittance of each of the band-pass polarizing patterns for light having a wavelength outside the wavelength range and having a polarization direction parallel to the absorption axis A of the band-pass polarizing pattern is less than 20%, and more preferably less than 10%. In other embodiments, in the range of visible light, the average transmittance of each of the band-pass polarizing patterns in at least another wavelength range (e.g., the main light-emitting wavelength range of another light-emitting structure) is less than 50%, and light having a wavelength outside the specific wavelength range substantially exhibits a polarizing property after passing through the band-pass polarizing pattern having the specific wavelength range.

[0029] For example, please refer to FIGS. 1 to Figure 3 In the present embodiment, the main light-emitting wavelengths of the first light-emitting structure ES1, the second light-emitting structure ES2, and the third light-emitting structure ES3 are 620 nm (e.g., red light), 530 nm (e.g., green light), and 460 nm (e.g., blue light), respectively. Therefore, in the range of visible light, the average transmittance of the band-pass polarizing pattern 131 overlapping the first light-emitting structure ES1 in the wavelength range of 620 ± 10 nm is greater than 50% (e.g., greater than 90%) (as shown in curve C1 of FIG. 1). The average transmittance of the band-pass polarizing pattern 132 overlapping the second light-emitting structure ES2 in the wavelength range of 530 ± 10 nm is greater than 50% (e.g., greater than 90%) (as shown in curve C2 of FIG. 1). The average transmittance of the band-pass polarizing pattern 133 overlapping the third light-emitting structure ES3 in the wavelength range of 460 ± 10 nm is greater than 50% (e.g., greater than 70%) (as shown in curve C3 of FIG. 1). In other embodiments, the average transmittance of the band-pass polarizing pattern 131 overlapping the first light-emitting structure ES1 in the wavelength range of 620 ± 10 nm is greater than 50% (e.g., greater than 70%), and the average transmittance in the wavelength ranges of 530 ± 10 nm and / or 460 ± 10 nm (e.g., in the ranges of green light and / or blue light) is less than 50% (as shown in curve C1 of FIG. 1). The average transmittance of the band-pass polarizing pattern 132 overlapping the second light-emitting structure ES2 in the wavelength range of 530 ± 10 nm is greater than 50% (e.g., greater than 70%), and the average transmittance in the wavelength ranges of 620 ± 10 nm and / or 460 ± 10 nm is less than 50% (as shown in curve C2 of FIG. 1). The average transmittance of the band-pass polarizing pattern 133 overlapping the third light-emitting structure ES3 in the wavelength range of 460 ± 10 nm is greater than 50% (e.g., greater than 70%), and the average transmittance in the wavelength ranges of 620 ± 10 nm and / or 530 ± 10 nm is less than 50% (as shown in curve C3 of FIG. 1). Figure 3 Figure 3 Figure 3 Figure 3 Figure 3 ​​​​than 50% (e.g., less than 20%) in the wavelength range outside the specific wavelength range. In other words, the band-pass polarizing pattern 131 has a high transmittance in the specific wavelength range and a low transmittance in the wavelength range outside the specific wavelength range. The average transmittance of the band-pass polarizing pattern 132 in the wavelength range of 460 ± 10 nm is greater than 50% (e.g., greater than 70%), and the average transmittance in the wavelength range of 620 ± 10 nm and / or 530 ± 10 nm is less than 50% (e.g., less than 20%). In other words, the band-pass polarizing pattern 132 has a high transmittance in the wavelength range of 460 ± 10 nm and a low transmittance in the wavelength range of 620 ± 10 nm and / or 530 ± 10 nm. The average transmittance of the band-pass polarizing pattern 133 in the wavelength range of 460 ± 10 nm is greater than 50% (e.g., greater than 70%), and the average transmittance in the wavelength range of 620 ± 10 nm and / or 530 ± 10 nm is less than 50% (e.g., less than 20%). In other words, the band-pass polarizing pattern 133 has a high transmittance in the wavelength range of 460 ± 10 nm and a low transmittance in the wavelength range of 620 ± 10 nm and / or 530 ± 10 nm. Figure 3 The average transmittance of the band-pass polarizing pattern 132 in the wavelength range of 460 ± 10 nm is greater than 50% (e.g., greater than 70%), and the average transmittance in the wavelength range of 620 ± 10 nm and / or 530 ± 10 nm is less than 50% (e.g., less than 20%). In other words, the band-pass polarizing pattern 132 has a high transmittance in the wavelength range of 460 ± 10 nm and a low transmittance in the wavelength range of 620 ± 10 nm and / or 530 ± 10 nm.

[0030] When the display pixels of the display device 10 are enabled (as shown in FIG. 1), the above-mentioned transmittance spectral characteristics of the band-pass polarizing patterns 131, 132, and 133 can allow the light rays LB1 (e.g., red light with a dominant emission wavelength of 620 nm) emitted by the first light-emitting structure ES1, the light rays LB2 (e.g., green light with a dominant emission wavelength of 530 nm) emitted by the second light-emitting structure ES2, and the light rays LB3 (e.g., blue light with a dominant emission wavelength of 460 nm) emitted by the third light-emitting structure ES3 to lose less optical energy after passing through the band-pass polarizing patterns 131, 132, and 133, respectively, thereby increasing the overall light output of the display device 10.

[0031] Since the average transmittance of the band-pass polarizing pattern in the wavelength range outside the specific wavelength range and in the polarization direction parallel to the absorption axis A of the band-pass polarizing pattern is less than 20% in the range of visible light, the light rays with wavelengths outside the specific wavelength range have polarizing characteristics after passing through the band-pass polarizing pattern. In other words, the band-pass polarizing pattern has a polarizing effect on the light rays with wavelengths outside the specific wavelength range. For example, when the light rays from the second light-emitting structure ES2 and emitted at a large angle (i.e., the light rays deviating more from the light rays LB2) pass through the band-pass polarizing pattern 131 or the band-pass polarizing pattern 133, substantial optical energy loss occurs. In other words, the arrangement of the band-pass polarizing patterns can also reduce the crosstalk between the light rays from different pixel areas PA, thereby improving the clarity of the display image.

[0032] From another perspective, the arrangement of the quarter-wave plate 120 and the band-pass polarizing layer 130 can also reduce the overall reflectivity of the display device 10 to external light rays from the surrounding environment. For example, please refer to Figure 1B , Figure 1BThe external ambient light EB1, the external ambient light EB2 and the external ambient light EB3 are, for example, red light with the same wavelength, and the external ambient light EB1, the external ambient light EB2 and the external ambient light EB3 are incident to the band-pass polarizing pattern 131, the band-pass polarizing pattern 132 and the band-pass polarizing pattern 133, respectively. Since the wavelength of the external ambient light EB1 is within the specific wavelength range (for example, 620±10 nm) of the band-pass polarizing pattern 131, the external ambient light EB1 is emitted from the display device 10 after passing through the band-pass polarizing pattern 131 and the quarter-wave plate 120 twice (incident to the display device 10 and reflected by the first electrode layer E1).

[0033] On the contrary, since the wavelength of the external ambient light EB2 is outside the specific wavelength range (for example, 530±10 nm) of the band-pass polarizing pattern 132, the light component with the polarization direction parallel to the absorption axis A of the band-pass polarizing pattern 132 is absorbed during the passing through the band-pass polarizing pattern 132. Therefore, the external ambient light EB2 has the first linear polarization state P1 after passing through the band-pass polarizing pattern 132. After passing through the quarter-wave plate 120, the polarization state of the external ambient light EB2 with the first linear polarization state P1 is further changed to the first circular polarization state CP1 (for example, right-handed circular polarization). After being reflected by the first electrode layer E1, the first circular polarization state CP1 of the external ambient light EB2 is changed to the second circular polarization state CP2 (for example, left-handed circular polarization) with the opposite handedness. After passing through the quarter-wave plate 120, the second circular polarization state CP2 of the external ambient light EB2 is further changed to the second linear polarization state P2 (the direction of the first linear polarization state P1 is perpendicular to the direction of the second linear polarization state P2). At this time, the external ambient light EB2 is absorbed by the band-pass polarizing pattern 132 because the polarization direction of the second linear polarization state P2 is parallel to the absorption axis A of the band-pass polarizing pattern 132. Since the band-pass polarizing pattern 133 and the quarter-wave plate 120 have the similar effects (for example, absorption effect) and principles on the external ambient light EB3 as the band-pass polarizing pattern 132 and the quarter-wave plate 120 on the external ambient light EB2, the details are not described herein.

[0034] In the present embodiment, the combination of the band-pass polarizing pattern and the quarter-wave plate 120 can make the average transmittance of the external ambient light less than the average transmittance of the external ambient light in the prior art when the external ambient light passes through twice and is outside the specific wavelength range. For example, the average transmittance of the combination of the quarter-wave plate 120 and the band-pass polarizing pattern 131 when the external ambient light passes through twice and is outside the wavelength range of 620±10 nm is less than the average transmittance of the external ambient light in the prior art, for example, less than 20% (as shown in FIG. 6). Figure 4the curve C1' of FIG. 11). The combination of the quarter-wave plate 120 and the band-pass polarizing pattern 132 has an average transmittance of less than 20% (e.g., as shown by the curve C1" of FIG. 11) for light having a wavelength outside the range of 620 ± 10 nm. Figure 4 the curve C2' of FIG. 11). The combination of the quarter-wave plate 120 and the band-pass polarizing pattern 133 has an average transmittance of less than 20% (e.g., as shown by the curve C3' of FIG. 11) for light having a wavelength outside the range of 460 ± 10 nm. Figure 4

[0035] For example, when the external ambient light is a standard D65 light source light (e.g., as shown by the curve D65 of FIG. 11), the composition of light having different wavelengths can be absorbed by different band-pass polarizing patterns. For example, the composition of light having a wavelength outside the range of 620 ± 10 nm can be absorbed by the combination of the band-pass polarizing pattern 131 and the quarter-wave plate 120 (e.g., as shown by the curve C1" of FIG. 11). The composition of light having a wavelength outside the range of 530 ± 10 nm can be absorbed by the combination of the band-pass polarizing pattern 132 and the quarter-wave plate 120 (e.g., as shown by the curve C2" of FIG. 11). The composition of light having a wavelength outside the range of 460 ± 10 nm can be absorbed by the combination of the band-pass polarizing pattern 133 and the quarter-wave plate 120 (e.g., as shown by the curve C3" of FIG. 11). Figure 5 Figure 5 Figure 5 Figure 5

[0036] Based on the above, when a portion of light having a specific wavelength (e.g., a red light wavelength, a green light wavelength, or a blue light wavelength) in the external ambient light passes through the quarter-wave plate 120 and the band-pass polarizing layer 130 twice, about two-thirds (roughly calculated in terms of area ratio) of the portion of light is absorbed by the band-pass polarizing layer 130, and only about one-third of the portion of light can be reflected back to the external ambient by the first electrode layer El of the display device 10. Therefore, when a portion or all of the light-emitting structures of the display device 10 are not enabled to present a local dark state or a full-area black screen, respectively, the arrangement of the quarter-wave plate 120 and the band-pass polarizing layer 130 described above can effectively improve the problem that the external ambient light reflected by the reflective electrode (i.e., the first electrode layer El) of the display device 10 is perceived by the human eye. That is, the overall reflectivity of the display device 10 to the external ambient light can be effectively reduced, which helps to improve the display quality (e.g., dark state performance) of the display device 10.

[0037] ​​​​​On the other hand, since the bandpass polarizing pattern still has an average transmittance of more than 50% for light within a specific wavelength range, while the prior art solution has an average transmittance of only about 40% for light within the same wavelength range, the light energy loss of the light emitted by the light-emitting structure (e.g., light rays LB1, LB2, and LB3) after passing through the bandpass polarizing layer 130 is significantly reduced compared to the conventional solution using a circular polarizer (i.e., the prior art). For example, in this embodiment, the bandpass polarizing pattern 131 has a transmittance of approximately 2.1 times that of the prior art for red light with a main emission wavelength of 620 nm (e.g., ...). Figure 6 As shown by curves C4 and C4p, where curve C4 is the transmittance curve of the present invention and curve Cp4 is the transmittance curve of the prior art. The bandpass polarization pattern 132 has a transmittance approximately 2.1 times that of the prior art for green light with a main emission wavelength of 530 nm (e.g., ...). Figure 6 (As shown by curves C5 and C5p). The bandpass polarization pattern 133 has a transmittance of approximately 1.7 times that of the prior art for blue light with a main emission wavelength of 460 nm (e.g., ...). Figure 6 (As shown by curves C6 and C6p). In other words, the arrangement of the quarter-wave plate 120 and the bandpass polarizing layer 130 not only improves the overall reflectivity of the display device 10 to external ambient light, but also effectively enhances the light energy utilization of the display device 10.

[0038] Other embodiments will be listed below to illustrate this disclosure in detail, wherein the same components will be labeled with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the foregoing embodiments, and they will not be repeated below.

[0039] Figure 7 This is a cross-sectional schematic diagram of a display device according to a second embodiment of the present invention. Please refer to... Figure 7 The display device 11 in this embodiment and Figure 1A The main difference between the display device 10 and the display device 11 lies in the arrangement of the bandpass polarizing layer. Specifically, the bandpass polarizing layer 130A of the display device 11 does not have a corresponding... Figure 1A The bandpass polarizing layer 130A of this embodiment overlaps with multiple portions of multiple light-emitting structures, all of which have the same spectral characteristics. For example, in this embodiment, the bandpass polarizing layer 130A is adapted to allow red light (e.g., wavelength 620±10nm), green light (e.g., wavelength 530±10nm), and blue light (e.g., wavelength 460±10nm) to pass through, i.e., the average transmittance within multiple specific wavelength ranges is greater than 50%, and the average transmittance of light outside the aforementioned wavelength ranges is less than 50%, wherein the aforementioned wavelength ranges do not overlap with each other. In other embodiments, the wavelength ranges in which the transmittance of the bandpass polarizing layer 130A is greater than 50% are all relatively...Figure 1A The passband of the passband polarizer 130 is further narrowed (e.g. ±5 nm of the main emission wavelength). Accordingly, the overall reflectance of the display device 11 to external ambient light can be further reduced.

[0040] On the other hand, the display device 11 of the present embodiment further comprises a wavelength conversion layer 150 disposed between the emissive structures ES and the passband polarizer 130A, specifically, between the encapsulation layer 140 and the emissive layer 110. For example, the wavelength conversion layer 150 can comprise a plurality of wavelength conversion patterns, a plurality of light transmission patterns 153 and a spacer layer 155. The spacer layer 155 is disposed between the wavelength conversion patterns and the light transmission patterns 153. The wavelength conversion patterns and the light transmission patterns 153 are respectively overlaid on the emissive structures ES of the emissive layer 110A in the direction Z, i.e. the spacer layer 155 is respectively overlaid on the spacer layer 115 in the direction Z.

[0041] In the present embodiment, the emissive structures ES of the emissive layer 110A all emit substantially the same color (or wavelength), e.g. blue. The plurality of wavelength conversion patterns comprises a plurality of wavelength conversion patterns 151 and a plurality of wavelength conversion patterns 152. The wavelength conversion patterns 151, the wavelength conversion patterns 152 and the light transmission patterns 153 are sequentially and alternately arranged along the direction X. For example, a portion of the blue light from the emissive structures ES is absorbed by the wavelength conversion patterns 151 and the wavelength conversion patterns 152 and generates red light and green light respectively with different wavelengths from the blue light, while another portion of the blue light directly passes through the light transmission patterns 153 without substantial loss of light energy, but not limited thereto. In other embodiments, the wavelength conversion layer can comprise a plurality of opening regions instead of the light transmission patterns 153.

[0042] In particular, the wavelength conversion effect of the wavelength conversion layer 150 can further reduce the full width at half maximum (FWHM) of the wavelength distribution of the display light, thereby reducing the light energy loss of the display light when passing through the passband polarizer 130A. In other words, the light energy utilization of the display device 11 can be further improved. On the other hand, since the emissive structures ES are all made of the same material, the service life (color fading) is more consistent, and therefore color shift with service life is less likely to occur.

[0043] Figure 8 is a cross-sectional view of a display device of a third embodiment of the present application. Figure 9 is Figure 8 is a schematic view of part of the film layers of the display device. Figure 10 is Figure 9 is a schematic view of another variant embodiment of the display device. Please refer to Figure 8 and Figure 9The display device 20 of the present embodiment differs from the display device 10 of Figure 1A the present embodiment is that the display device is composed differently. More specifically, the display device 20 of the present embodiment also has the function of preventing the display from being viewed.

[0044] In the present embodiment, the display device 20 can also selectively include a viewing angle limiter 200, which is disposed in an overlapping manner with the band-pass polarizing layer 130B. The band-pass polarizing layer 130B is located between the viewing angle limiter 200 and the quarter-wave plate 120. For example, the viewing angle limiter 200 has a first absorption coefficient in the thickness direction (e.g., direction Z) and a second absorption coefficient in a direction perpendicular to the thickness direction, and the ratio of the first absorption coefficient to the second absorption coefficient can be between 2 and 10,000. In a preferred embodiment, the ratio of the first absorption coefficient to the second absorption coefficient of the viewing angle limiter 200 is between 10 and 1,000.

[0045] In the present embodiment, the light-emitting layer 110 can include a plurality of first pixel light-emitting structures and a plurality of second pixel light-emitting structures and be arranged alternately along the direction X. These first pixel light-emitting structures are, for example, a plurality of first light-emitting structures ES1A, a plurality of second light-emitting structures ES2A, and a plurality of third light-emitting structures ES3A. These second pixel light-emitting structures are, for example, a plurality of first light-emitting structures ES1B, a plurality of second light-emitting structures ES2B, and a plurality of third light-emitting structures ES3B. The first light-emitting structures ES1A, the second light-emitting structures ES2A, the third light-emitting structures ES3A, the first light-emitting structures ES1B, the second light-emitting structures ES2B, and the third light-emitting structures ES3B are arranged alternately along the direction X.

[0046] It is noted that the band-pass polarizing layer 130B includes first pixel band-pass polarizing patterns and second pixel band-pass polarizing patterns and is arranged alternately along the direction X. The first pixel band-pass polarizing patterns are, for example, a plurality of first band-pass polarizing patterns 131A, a plurality of first band-pass polarizing patterns 132A, and a plurality of first band-pass polarizing patterns 133A. The second pixel band-pass polarizing patterns are, for example, a plurality of second band-pass polarizing patterns 131B, a plurality of second band-pass polarizing patterns 132B, and a plurality of second band-pass polarizing patterns 133B. In the direction Z, the first pixel band-pass polarizing patterns and the second pixel band-pass polarizing patterns overlap the first pixel light-emitting structures and the second pixel light-emitting structures, respectively, that is, the first band-pass polarizing patterns are arranged to overlap a portion of the first light-emitting structures and a portion of the second light-emitting structures, respectively, and the second band-pass polarizing patterns are arranged to overlap another portion of the first light-emitting structures and another portion of the second light-emitting structures, respectively. Specifically, the first band-pass polarizing patterns 131A, the first band-pass polarizing patterns 132A, the first band-pass polarizing patterns 133A, the second band-pass polarizing patterns 131B, the second band-pass polarizing patterns 132B, and the second band-pass polarizing patterns 133B overlap the first light-emitting structure ES1A, the second light-emitting structure ES2A, the third light-emitting structure ES3A, the first light-emitting structure ES1B, the second light-emitting structure ES2B, and the third light-emitting structure ES3B, respectively, in the direction Z.

[0047] In the present embodiment, the absorption axes A1 of the first band-pass polarizing patterns are perpendicular to the absorption axes A2 of the second band-pass polarizing patterns, and the absorption axes A1 and the absorption axes A2 each form an angle of 45 degrees with the optical axis n of the quarter-wave plate 120. Through the arrangement of the viewing angle limiter 200 and the partition design of the absorption axes of the band-pass polarizing patterns, the display device 20 has the privacy display effect in the direction X or the direction Y. Specifically, the display device 20 can enable the first pixel light-emitting structures and the second pixel light-emitting structures, only the first pixel light-emitting structures, or only the second pixel light-emitting structures, so that the display device 20 operates in the sharing mode, the X-direction privacy mode, or the Y-direction privacy mode, respectively.

[0048] Please refer to Figure 10 In another embodiment, the display device 20A having the privacy display function can selectively include a phase delay film 160 arranged between the viewing angle limiter 200 and the band-pass polarizing layer 130B, and the optical axis n' of the phase delay film 160 is parallel or perpendicular to the absorption axes of the band-pass polarizing layer 130B. For example, the optical axis n' of the phase delay film 160 is parallel to the absorption axes A1 of the first band-pass polarizing patterns and perpendicular to the absorption axes A2 of the second band-pass polarizing patterns, but is not limited thereto.

[0049] Figure 11 is a cross-sectional schematic view of a display device of a fourth embodiment of the present application. Figure 12 is Figure 11 is a schematic view of partial film layers of the display device of Figure 11 and Figure 12 The display device 20B of the present embodiment differs from the display device 20 of Figure 8 in that the axial directions of the absorption axes of the band-pass polarizing layer are different. Specifically, the display device 20B employs the band-pass polarizing layer 130 that is identical to that of Figure 2 , i.e., the axial directions of the absorption axes A of the plurality of band-pass polarizing patterns of the band-pass polarizing layer 130 are identical.

[0050] To this end, the display device 20B further includes a half-wave plate 170 that is disposed in superposition with the band-pass polarizing layer 130 and between the viewing angle limiter 200 and the band-pass polarizing layer 130. It is particularly noted that the half-wave plate 170 has a plurality of first sub-zones Z1 and a plurality of second sub-zones Z2. The first sub-zones Z1 are respectively overlaid on the plurality of first pixel light-emitting structures (e.g., the first, second, and third light-emitting structures ES1A, ES2A, and ES3A) in the direction Z, and the second sub-zones Z2 are respectively overlaid on the plurality of second pixel light-emitting structures (e.g., the first, second, and third light-emitting structures ES1B, ES2B, and ES3B) in the direction Z.

[0051] In the present embodiment, the angle between the first optical axis n1 of the first sub-zone Z1 of the half-wave plate 170 and the absorption axis A of the band-pass polarizing pattern is 45 degrees, and the axial direction of the second optical axis n2 of the second sub-zone Z2 of the half-wave plate 170 is parallel to the axial direction of the absorption axis A of the band-pass polarizing pattern. However, the present application is not limited thereto, and in another embodiment, the axial direction of the second optical axis n2 of the second sub-zone Z2 of the half-wave plate 170 can also be perpendicular to the axial direction of the absorption axis A of the band-pass polarizing pattern. In yet another embodiment, the second sub-zone Z2 of the half-wave plate 170 is an open area (or filled with a light-transmissive material), i.e., no material of the half-wave plate is provided in the second sub-zone Z2.

[0052] In summary, in the display device of an embodiment of the present application, a quarter-wave plate is provided with a band-pass polarizing layer on the side away from the light-emitting layer. The plurality of first band-pass polarizing patterns of the band-pass polarizing layer have an average transmittance greater than 50% for light in a specific wavelength range, and an average transmittance less than 20% and a polarizing effect for light in the range of visible light that is outside the specific wavelength range and has a polarization direction parallel to the absorption axis of the first band-pass polarizing pattern. In this way, in addition to increasing the overall light output of the display device, the overall reflectivity of the display device to external ambient light can also be reduced, thereby improving the light energy utilization rate and dark state performance of the display device.

[0053] While the present application has been disclosed in connection with the embodiments presented, it should be understood that there can be other embodiments which fall within the spirit and scope of the application, as defined by the appended claims, and that modifications can be made without departing from the spirit and scope of the application. Any further modifications made will also fall within the scope of the present application.

[0054] BRIEF DESCRIPTION OF DRAWINGS

[0055] 10, 11, 20, 20A, 20B: display device

[0056] 100: circuit substrate

[0057] 110, 110A: light-emitting layer

[0058] 115, 155: spacer structure layer

[0059] 115a: opening

[0060] 120: quarter-wave plate

[0061] 130, 130A, 130B: band-pass polarizing layer

[0062] 131, 132, 133, 131A, 132A, 133A, 131B, 132B, 133B: band-pass polarizing pattern

[0063] 140: encapsulation layer

[0064] 150: wavelength conversion layer

[0065] 151, 152: wavelength conversion pattern

[0066] 153: light-transmitting pattern

[0067] 160: phase retardation film

[0068] 170: half-wave plate

[0069] A, A1, A2: absorption axis

[0070] CP1: first circular polarization state

[0071] CP2: second circular polarization state

[0072] E1: first electrode layer

[0073] E2: second electrode layer

[0074] EB1, EB2, EB3: external ambient light

[0075] ES: light-emitting structure

[0076] ES 1, ES 1A, ES 1B: first light-emitting structure

[0077] ES2, ES2A, ES2B: second light emitting structure

[0078] ES3, ES3A, ES3B: third light emitting structure

[0079] LB1, LB2, LB3: light ray

[0080] n, n1, n2, n’: optical axis

[0081] P1: first linear polarization state

[0082] P2: second linear polarization state

[0083] PA: pixel area

[0084] X, Y, Z: direction

[0085] Z1: first sub-area

[0086] Z2: second sub-area.

Claims

1. A display device, characterized by comprising: The display device comprises a circuit substrate, a light-emitting layer, a quarter-wave plate, and a band-pass polarizing layer, wherein: The light-emitting layer is arranged on the circuit substrate and has a plurality of light-emitting structures, the plurality of light-emitting structures are arranged on the circuit substrate in an overlapping manner and are electrically connected to the circuit substrate, the plurality of light-emitting structures comprise a plurality of first light-emitting structures, the plurality of first light-emitting structures have a first main light-emitting wavelength; The quarter-wave plate is arranged on the plurality of light-emitting structures of the light-emitting layer in an overlapping manner; and The band-pass polarizing layer is arranged on the quarter-wave plate in an overlapping manner, the quarter-wave plate is located between the band-pass polarizing layer and the light-emitting layer, the band-pass polarizing layer comprises a plurality of first band-pass polarizing patterns, each of the plurality of first band-pass polarizing patterns has a first absorption axis, the average transmittance of the plurality of first band-pass polarizing patterns to light with a wavelength in a first wavelength range is greater than 50%, the first wavelength range is the first main light-emitting wavelength ± 10 nm, and the average transmittance of the plurality of first band-pass polarizing patterns to light with a wavelength outside the first wavelength range and a polarization direction parallel to the first absorption axis is less than 20% in the range of visible light, wherein the non-polarized light with a wavelength in the first wavelength range is non-linearly polarized light after passing through the plurality of first band-pass polarizing patterns, and the non-polarized light with a wavelength outside the first wavelength range forms linearly polarized light after passing through the plurality of first band-pass polarizing patterns.

2. The display device according to claim 1, wherein The angle between the optical axis of the quarter-wave plate and the first absorption axis of the band-pass polarizing layer is 45 degrees.

3. The display device according to claim 1, wherein The plurality of light-emitting structures further comprise a plurality of second light-emitting structures, the plurality of second light-emitting structures have a second main light-emitting wavelength, the first main light-emitting wavelength is different from the second main light-emitting wavelength, the band-pass polarizing layer further comprises a plurality of second band-pass polarizing patterns, the plurality of first band-pass polarizing patterns are arranged on the plurality of first light-emitting structures in an overlapping manner respectively, the plurality of second band-pass polarizing patterns are arranged on the plurality of second light-emitting structures in an overlapping manner respectively, and the average transmittance of the plurality of second band-pass polarizing patterns to light with a wavelength in a second wavelength range is greater than 50%, wherein the second wavelength range is the second main light-emitting wavelength ± 10 nm.

4. The display device according to claim 3, wherein The plurality of light-emitting structures further comprise a plurality of third light-emitting structures, the plurality of third light-emitting structures have a third main light-emitting wavelength, the band-pass polarizing layer further comprises a plurality of third band-pass polarizing patterns, and the plurality of third band-pass polarizing patterns are arranged on the plurality of third light-emitting structures in an overlapping manner respectively, wherein the first main light-emitting wavelength is greater than 600 nm, the second main light-emitting wavelength is between 500 nm and 600 nm, and the third main light-emitting wavelength is less than 500 nm.

5. The display device according to claim 1, wherein The light-emitting layer further comprises a first electrode layer, the first electrode layer is electrically connected to the plurality of light-emitting structures, the first electrode layer is located between the plurality of light-emitting structures and the circuit substrate, and the first electrode layer is a reflective electrode layer.

6. The display device according to claim 3, wherein Each of the plurality of second band-pass polarizing patterns has the first absorption axis, and the plurality of first absorption axes of the plurality of first band-pass polarizing patterns and the plurality of second band-pass polarizing patterns have the same axial direction.

7. The display device according to claim 1, wherein The multiple first absorption axes of the multiple first band-pass polarization patterns have different axial directions.

8. The display device according to claim 1, wherein The first band-pass polarization pattern has an average transmittance greater than 50% for light having a wavelength in the first wavelength range, a second wavelength range, and a third wavelength range, and an average transmittance less than 50% for light having a wavelength outside the first wavelength range, the second wavelength range, and the third wavelength range, the first wavelength range, the second wavelength range, and the third wavelength range being non-overlapping with each other.

9. The display device according to claim 8, wherein Further comprising: a plurality of wavelength conversion patterns, which are disposed in at least part of the multiple light-emitting structures and between the multiple light-emitting structures and the band-pass polarization layer.

10. The display device according to claim 9, wherein Further comprising: a plurality of light-transmitting patterns, which are disposed in at least another part of the multiple light-emitting structures and between the multiple light-emitting structures and the band-pass polarization layer.

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