Display device and method for manufacturing display device

Abstract

A polarizing member (4) comprises a base material (5) and a polarizing layer (6) located on the base material (5), both surfaces of the base material (5) and both surfaces of the polarizing layer (6) are flat, the polarizing layer (6) includes a first area (7) having a first polarization capability index that is a polarization capability index of 99% or greater and a second area (8) having a second polarization capability index that is a polarization capability index of less than 99%.

Description

Display Device and Method for Manufacturing Display Device

[0001] The present disclosure relates to a display device and a method for manufacturing a display device.

[0002] Patent Document 1 discloses an electroluminescent display device in which a patterned polarizing layer of a polarizing plate includes a region A having a polarization degree of less than 80% and a region B having a polarization degree of 80% or more, and the position of the region A corresponds to the position of a light emitting element.

[0003] International Publication No. WO2019 / 176918 A1

[0004] In the electroluminescent display device disclosed in Patent Document 1, since the surface of the patterned polarizing layer is uneven, there is a possibility that the color tone or the like of a display image varies depending on the viewing angle of the display image.

[0005] In the electroluminescent display device disclosed in Patent Document 1, the direction in which the most light is extracted is the normal direction of the surface of the patterned polarizing layer. When viewed macroscopically, the surface of the patterned polarizing layer according to Patent Document 1 is uneven, while when viewed microscopically, it is an aggregate of a large number of surfaces facing various directions. Therefore, in the case of monochromatic display, when the display image is viewed obliquely, the color tone of the display image may be different from that when the display image is viewed from the front. Furthermore, in the case of color display combining a plurality of colors, such difference in color tone of the display image occurs for each color, so even when the display image is viewed from the front, there is a possibility that the desired color tone of the display image cannot be obtained.

[0006] Therefore, Patent Document 1 has a problem of low display quality.

[0007] A display device according to one aspect of the present disclosure, with an observer side defined as an upper side, includes: a first light emitting element; and a polarizing member located in an upper layer relative to the first light emitting element, wherein the polarizing member includes a base material and a polarizing layer located on the base material, both surfaces of the base material and both surfaces of the polarizing layer are each flat, and the polarizing layer includes a first portion having a first polarization capability index of 99% or more, and a second portion having a second polarization capability index of less than 99%.

[0008] According to one aspect of this disclosure, a display device with high display quality can be realized.

[0009] This is an overall plan view of the display device according to Embodiment 1 of the present disclosure. This is a cross-sectional view showing the configuration of the display device according to Embodiment 1 of the present disclosure. This is a cross-sectional view showing the specific configuration of the polarizing member. This is a cross-sectional view showing a first example of a method for manufacturing the display device according to Embodiment 1 of the present disclosure. This is a cross-sectional view showing a second example of a method for manufacturing the display device according to Embodiment 1 of the present disclosure. This is a cross-sectional view showing a third example of a method for manufacturing the display device according to Embodiment 1 of the present disclosure. This is a cross-sectional view showing a fourth example of a method for manufacturing the display device according to Embodiment 1 of the present disclosure. This is a cross-sectional view showing the configuration of the display device according to Embodiment 2 of the present disclosure. This is a cross-sectional view showing the configuration of the display device according to Embodiment 3 of the present disclosure. This is a cross-sectional view showing the configuration of the display device according to Embodiment 4 of the present disclosure.

[0010] The following describes the forms for implementing this disclosure. For the sake of convenience, components having the same function as those described earlier will be denoted by the same reference numerals, and their descriptions may not be repeated.

[0011] [Embodiment 1] Figure 1 is an overall plan view of a display device 101 according to Embodiment 1 of the present disclosure. Figure 2 is a cross-sectional view showing the configuration of the display device 101 according to Embodiment 1 of the present disclosure. The display device 101 includes an image display area 65 for displaying an image, and a frame 66 located around the image display area 65. The first light-emitting element 1, the second light-emitting element 2, the third light-emitting element 3, the second part 8, the third part 9, and the fourth part 10, which will be described later, are located within the image display area 65. The display device 101 includes a TFT substrate 51, the first light-emitting element 1, the second light-emitting element 2, and the third light-emitting element 3, a TFE (tetrafluoroethylene) layer 52, and a polarizing member 4, with the observer 50 side facing upwards. Examples of the first light-emitting element 1 include an OLED element and a QLED element. Examples of the second light-emitting element 2 include an OLED element and a QLED element. Examples of the third light-emitting element 3 include an OLED element and a QLED element. TFT is an abbreviation for Thin Film Transistor. OLED stands for Organic Light Emitting Diode. QLED stands for Quantum Light Emitting Diode.

[0012] Each of the first light-emitting element 1, the second light-emitting element 2, and the third light-emitting element 3 has an anode 53, a hole transport layer 54, a light-emitting layer 55, an electron transport layer 56, and a cathode 57.

[0013] Typical materials for anode 53 include inorganic materials with high work functions such as ITO and IZO, with a film thickness of 50 nm or more and 100 nm or less. ITO is an abbreviation for Indium Tin Oxide. IZO is an abbreviation for Indium Zinc Oxide. A metal film such as Ag and APC is laminated beneath the inorganic material of anode 53 to provide reflective properties. Here, APC is an alloy of Ag, Pd, and Cu. The film thickness of this metal film is 50 nm or more and 100 nm or less.

[0014] Typical materials for the hole transport layer 54 include organic materials such as α-NPD and TPD, and the film thickness is 20 nm or more and 60 nm or less. α-NPD is an abbreviation for N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine. TPD is an abbreviation for N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine.

[0015] The light-emitting layer 55 is typically made of Alq. ３ Examples include organic materials such as [material name] and inorganic materials such as QD, with a film thickness of 20 nm or more and 60 nm or less. QD is an abbreviation for Quantum Dot and is also called a quantum dot.

[0016] Typical materials for the electron transport layer 56 include organic materials such as BCP and inorganic materials such as ZnO, with a film thickness of 30 nm or more and 80 nm or less. BCP is an abbreviation for 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0017] Typical materials for cathode 57 include metallic materials with low work functions such as Al and MgAg, with a film thickness of 10 nm or more and 30 nm or less.

[0018] The hole transport layer 54 may be used between the first light-emitting element 1, the second light-emitting element 2, and the third light-emitting element 3. The electron transport layer 56 may be used between the first light-emitting element 1, the second light-emitting element 2, and the third light-emitting element 3. The cathode 57 may be used between the first light-emitting element 1, the second light-emitting element 2, and the third light-emitting element 3. In Figure 2, the anode 53 of the first light-emitting element 1 is indicated by reference numeral 531, the anode 53 of the second light-emitting element 2 is indicated by reference numeral 532, and the anode 53 of the third light-emitting element 3 is indicated by reference numeral 533. In Figure 2, the light-emitting layer 55 of the first light-emitting element 1 is indicated by reference numeral 551, the light-emitting layer 55 of the second light-emitting element 2 is indicated by reference numeral 552, and the light-emitting layer 55 of the third light-emitting element 3 is indicated by reference numeral 553.

[0019] Figure 3 is a cross-sectional view showing the specific configuration of the polarizing member 4. The polarizing member 4 is located above the first light-emitting element 1, above the second light-emitting element 2, and above the third light-emitting element 3. The polarizing member 4 includes a λ / 4 wave plate 58, a substrate 5, a polarizing layer 6, and a TAC (triacetylcellulose) film 59. TAC is an example of the material of the substrate 5. The polarizing layer 6 is located on top of the substrate 5.

[0020] The thickness of the λ / 4 wave plate 58 is 100 nm or more and 200 nm or less. The material of the substrate 5 is TAC, and its thickness is 80 μm or more and 100 μm or less. The polarizing layer 6 is a polymer layer such as PVA (polyvinyl alcohol) containing iodine, and its thickness is 10 μm or more and 20 μm or less. The thickness of the TAC film 59 is the same as the substrate 5, 80 μm or more and 100 μm or less.

[0021] Both sides of the substrate 5 and both sides of the polarizing layer 6 are flat. "Flat" may mean, for example, that the surface has an arithmetic mean roughness Ra of 100 nm or less, or that the boundary between the two members is formed continuously and smoothly. "Flat" may also mean, for example, that the height difference between the two members is 100 nm or less.

[0022] The polarizing layer 6 includes a first portion 7 and a second portion 8. The first portion 7 has a first polarization capability index of 99% or more. The second portion 8 has a second polarization capability index of less than 99%. Here, "polarization capability index of 99% or more" may be a de facto polarization capability index of 100%. Here, "polarization capability index of less than 99%" may be a de facto polarization capability index of less than 100%.

[0023] Here, the polarizing layer 6 may contain iodine, and the polarization capability index of the polarizing layer is expressed as a percentage based on the polarization capability index of 0% and 100% as defined below, where Lin is the light that enters perpendicularly from the outside to the display device 101, and Lnt is the light that is reflected in the display device 101, polarized by the polarizing layer 6, and exits to the outside.

[0024] Polarization capability index 0%: The intensity P1 of light Lnt when light Lin is reflected by the display device 101 in the absence of a polarizing layer. Polarization capability index 100%: The intensity P2 of light Lnt when light Lin is incident on the first part 7. In other words, if {(intensity of P1 - Lnt) / (P1 - P2)} × 100 = X, the polarization capability index is expressed as X%.

[0025] According to the display device 101, since both sides of the substrate 5 and both sides of the polarizing layer 6 are flat, the risk of the color of the displayed image differing depending on the viewing angle can be reduced. Therefore, a display device 101 with good viewing angle characteristics and high display quality that does not change color due to differences in viewing angle can be realized.

[0026] As a specific example of the polarizing layer 6, the polarizing layer 6 may contain 50% by weight or less of iodine relative to the matrix. The polarizing layer 6 may also be a component of a so-called iodine-type polarizing plate. The concentration of iodine in the second portion 8 may be lower than the concentration of iodine in the first portion 7. For example, it may be 30% by weight or less. Alternatively, the polarizing layer 6 may be constructed using a material having similar properties to iodine. This makes it possible to achieve both flat surfaces on both sides of the substrate 5 and both sides of the polarizing layer 6, and that the polarizing layer 6 includes the first portion 7 and the second portion 8.

[0027] In a plan view of the display device 101, at least a portion of the first light-emitting element 1 and at least a portion of the second part 8 may overlap. The overlapping area of ​​at least a portion of the first light-emitting element 1 and at least a portion of the second part 8 in a plan view of the display device 101 may be 10 μm or more and 100 μm or less. This can reduce the decrease in the efficiency of extracting light emitted by the first light-emitting element 1. In a plan view of the display device 101, the first light-emitting element 1 and the second part 8 may overlap. In a cross-sectional view of the display device 101, the length of the overlapping area of ​​the first light-emitting element 1 and the second part 8 may be 10 μm or more and 100 μm or less.

[0028] The boundary portion 78P between the upper surface 7P of the first portion 7 and the upper surface 8P of the second portion 8 may be formed continuously and smoothly. The difference between the height of the upper surface 7P of the first portion 7 and the height of the upper surface 8P of the second portion 8 may be 100 nm or less. Each of these corresponds to both sides of the substrate 5 and both sides of the polarizing layer 6 being flat.

[0029] The second polarization capability index may be 50% or less. In particular, when the first light-emitting element 1 emits blue light, the luminous sensitivity of blue light is low, so it is reasonable to reduce the second polarization capability index by prioritizing the brightness of blue light. Here, blue refers to light with a wavelength of approximately 430 nm or more and 500 nm or less, red refers to light with a wavelength of approximately 600 nm or more and 700 nm or less, and green refers to light with a wavelength of approximately 500 nm or more and 600 nm or less.

[0030] The display device 101 includes a second light-emitting element 2 and a third light-emitting element 3 located below the polarizing member 4. The second light-emitting element 2 may emit light in a different color from the first light-emitting element 1. The third light-emitting element 3 may emit light in a different color from both the first light-emitting element 1 and the second light-emitting element 2. The first light-emitting element 1, the second light-emitting element 2, and the third light-emitting element 3 are located horizontally. The polarizing layer 6 may include a third portion 9 having a third polarization capability index of less than 99%, and a fourth portion 10 having a fourth polarization capability index of less than 99%. In a plan view of the display device 101, at least a part of the second light-emitting element 2 and at least a part of the third portion 9 may overlap, and at least a part of the third light-emitting element 3 and at least a part of the fourth portion 10 may overlap.

[0031] This reduces the decrease in the efficiency of extracting light emitted by the second light-emitting element 2, and also reduces the decrease in the efficiency of extracting light emitted by the third light-emitting element 3. In a plan view of the display device 101, the second light-emitting element 2 and the third part 9 may overlap, and the third light-emitting element 3 and the fourth part 10 may overlap.

[0032] Here, light extraction efficiency is expressed as a percentage of Lpol / Lemt, where Lemt is the intensity of light emitted from the light-emitting layer and Lpol is the intensity of light emitted from the polarizing plate. In other words, if Lpol / Lemt × 100 = X, the light extraction efficiency is expressed as X%.

[0033] There is a demand for higher brightness in display devices such as OLEDs. Display devices use a metal with high surface reflectivity (for example, Ag or APC) beneath the lower electrode, and since this causes surface reflection at a wide viewing angle, a polarizing element is provided on its surface.

[0034] On the other hand, the presence of a polarizing element may reduce the light extraction efficiency of the display device. To address this concern, by reducing or eliminating light absorption by the polarizing element only on the pixels, it is possible to suppress surface reflection while increasing light extraction efficiency.

[0035] When polarizing elements containing iodine are formed by photolithography etching or decolorization using base treatment with sodium hydroxide or potassium hydroxide, irregularities occur on the surface of the polarizing element. If the polarization capability index is adjusted for each pixel, this can lead to abnormalities in the degree of specular reflection and the color of the displayed image, resulting in a significant change in color when the displayed image is viewed from an oblique angle.

[0036] Generally, iodine-type polarizers are known to be susceptible to ultraviolet light, heat, and moisture (humidity). However, in the display device 101 of this embodiment, this characteristic is used in reverse to partially decolorize the polarizing layer 6, thereby maintaining a flat surface across the entire polarizing layer 6. Furthermore, by selecting and using a substrate 5 with a flat surface, it is possible to lower the polarization capability index in desired locations. This provides a display device 101 with no surface roughness and suppresses the degradation of display quality caused by uneven surfaces on the substrate 5 and / or the polarizing layer 6. Additionally, the display device 101 solves the problem of abnormalities in the degree of specular reflection and the color of the displayed image when it is desired to change the polarization capability index for each pixel. If the decolorization process of the polarizing layer 6 uses ultraviolet light, the polarization capability index can be easily adjusted by controlling the irradiation time and intensity. In the display device 101, decolorization of the polarizing layer 6 is possible even after the TAC film 59 has been laminated.

[0037] Figure 4 is a cross-sectional view showing a first example of a method for manufacturing a display device 101 according to Embodiment 1 of the present disclosure. In the first example, a mask 14 is formed so as to expose the upper parts 11, 12, and 13 of the portion of the polarizing layer 6 whose polarization capability index is to be reduced, and ultraviolet light 15 is irradiated onto the exposed portion to form a second portion 8.

[0038] The mask 14 is preferably made of a metal material such as aluminum or stainless steel that does not transmit ultraviolet light. The wavelength range of the ultraviolet light 15 used here is 300 nm or more and 450 nm or less.

[0039] In the first example, a mask 14 is first formed on the TAC film 59 (see Figure 3) so as to expose the upper parts 11, 12, and 13 of the portion of the polarizing layer 6 whose polarization capability index is to be reduced.

[0040] In a plan view of the display device 101, an opening 60 is formed in the mask 14 at a position overlapping at least a part of the first light-emitting element 1, an opening 61 is formed at a position overlapping at least a part of the second light-emitting element 2, and an opening 62 is formed at a position overlapping at least a part of the third light-emitting element 3. Ultraviolet rays 15 are irradiated to the portion where the opening 60 is formed, the portion where the opening 61 is formed, and the portion where the opening 62 is formed (the above-described exposed portions). Irradiation with the ultraviolet rays 15 decomposes iodine contained immediately below the opening 60 in the polarizing layer 6, whereby the second region 8 can be formed. Irradiation with the ultraviolet rays 15 decomposes iodine contained immediately below the opening 61 in the polarizing layer 6, whereby the third region 9 can be formed. Irradiation with the ultraviolet rays 15 decomposes iodine contained immediately below the opening 62 in the polarizing layer 6, whereby the fourth region 10 can be formed.

[0041] In a plan view of the display device 101, only the portion of the polarizing layer 6 overlapping at least a part of the first light-emitting element 1, the portion of the polarizing layer 6 overlapping at least a part of the second light-emitting element 2, and the portion of the polarizing layer 6 overlapping at least a part of the third light-emitting element 3 may be whitened. The whitening method may be irradiation with the ultraviolet rays 15. Iodine may be decomposed in a part of the polarizing layer 6 by light energy to reduce the polarization performance index. Regarding the TAC film 59, the TAC film can be replaced with a film made of a material other than TAC as long as the material is capable of protecting the polarizing layer 6 and has visible light transmittance, such as glass and quartz.

[0042] According to the display device 101, since the base material 5 and the whitened polarizing layer 6 are flat, even if the polarization performance index differs for each pixel, the risk of causing abnormalities in the degree of specular reflection and the color tone of a displayed image can be reduced.

[0043] Fig. 5 is a cross-sectional view showing a second example of the method for manufacturing the display device 101 according to Embodiment 1 of the present disclosure. The second example is a method of forming the second region 8 by irradiating an ultraviolet laser beam (laser beam) 16 to portions 11, 12, and 13 above the region of the polarizing layer 6 where it is desired to lower the polarization performance index.

[0044] In the second example, without using a mask 14, ultraviolet laser light 16 is irradiated onto portions 11, 12, and 13 above regions where it is desired to reduce the polarization capability index of a polarizing layer 6, thereby forming a second region 8, a third region 9, and a fourth region 10. In the second example, selective blanking is performed by the ultraviolet laser light 16 (light energy).

[0045] FIG. 6 is a cross-sectional view illustrating a third example of a method for manufacturing the display device 101 according to the first embodiment of the present disclosure. The third example is a method for forming the second region 8 by irradiating an infrared laser beam (laser beam) 17 onto portions 11, 12, and 13 above regions where it is desired to reduce the polarization capability index of the polarizing layer 6.

[0046] In the third example, while using the mask 14 as a reflective member to suppress the diffusion of heat caused by the infrared laser beam 17, the infrared laser beam 17 is irradiated onto portions 11, 12, and 13 above regions where it is desired to reduce the polarization capability index of the polarizing layer 6, thereby forming the second region 8, the third region 9, and the fourth region 10. Examples of infrared lasers include a YAG laser (λ=1.06 µm) and CO ２ 2 laser (λ=10.6 µm). Iodine may be decomposed in a portion of the polarizing layer 6 by thermal energy to reduce the polarization capability index.

[0047] FIG. 7 is a cross-sectional view illustrating a fourth example of a method for manufacturing the display device 101 according to the first embodiment of the present disclosure. In the fourth example, banks 18 are formed to expose portions 11, 12, and 13 above regions where it is desired to reduce the polarization capability index of the polarizing layer 6, and to surround the exposed portions in a plan view of the display device 101, and water 19 is dropped onto the exposed portions to form the second region 8, after which the water 19 is removed. The method for removing the water 19 is N ２ 2 blowing. The liquid temperature of the water 19 is 10°C or higher and 90°C or lower.

[0048] In the fourth example, first, a transparent protective film 63 is formed on the polarizing member 4. Subsequently, by etching the transparent protective film 63, the upper parts 11, 12, and 13 of the portion of the polarizing layer 6 whose polarization capability index is to be reduced are exposed, and a bank 18 is formed so as to surround the upper parts 11, 12, and 13 of the portion of the polarizing layer 6 whose polarization capability index is to be reduced in a plan view of the display device 101. Water 19 is dropped onto the upper parts 11, 12, and 13 of the portion of the polarizing layer 6 whose polarization capability index is to be reduced to form a second portion 8, a third portion 9, and a fourth portion 10, and then the water 19 is removed. By dropping water 19, iodine may be decomposed in a part of the polarizing layer 6, thereby reducing the polarization capability index. In the fourth example, the missing portion of the transparent protective film 63 created when the bank 18 is formed may be filled with the material of the transparent protective film 63, restoring it to a flat transparent film 64, thereby making the surface of the display device 101 flat.

[0049] In the display device 101, the polarization capability index of the second part 8 (second polarization capability index), the polarization capability index of the third part 9 (third polarization capability index), and the polarization capability index of the fourth part 10 (fourth polarization capability index) may be approximately 0%.

[0050] [Embodiment 2] Figure 8 is a cross-sectional view showing the configuration of a display device 101 according to Embodiment 2 of the present disclosure. The display device 101 includes a second light-emitting element 2 located below the polarizing member 4 and emitting light of a different color from the first light-emitting element 1. The first light-emitting element 1 and the second light-emitting element 2 are located in the horizontal direction. In a plan view of the display device 101, at least a part of the second light-emitting element 2 and at least a part of the first part 7 may overlap. The polarizing layer 6 does not have to include the third part 9. The polarizing layer 6 does not have to include the fourth part 10. The polarization capability index (second polarization capability index) of the second part 8 may be approximately 0%.

[0051] In a cross-sectional view of the display device 101, at least one type of light-emitting element and the white portion of the polarizing layer 6 may overlap in a range of 10 μm or more and 100 μm or less in length, and at least one type of light-emitting element and the non-white portion of the polarizing layer 6 may overlap in a range of 10 μm or more and 100 μm or less in length. In a cross-sectional view of the display device 101, the blue-emitting light-emitting element and the white portion of the polarizing layer 6 may overlap in a range of 10 μm or more and 100 μm or less in length, the green-emitting light-emitting element and the non-white portion of the polarizing layer 6 may overlap in a range of 10 μm or more and 100 μm or less in length, and the red-emitting light-emitting element and the non-white portion of the polarizing layer 6 may overlap in a range of 10 μm or more and 100 μm or less in length.

[0052] The first part 7, the second part 8, the third part 9, and the fourth part 10 are selectively patternable. In the display device 101, the luminous sensitivity and luminous efficiency differ for each light-emitting color of the light-emitting element, and therefore the degree of contribution to current consumption differs. Here, the luminous sensitivity of blue is 10 lm / W or more and less than 300 lm / W, the luminous sensitivity of red is 300 lm / W or more and less than 600 lm / W, and the luminous sensitivity of green is 600 lm / W or more and 1000 lm / W or less. Here, the current efficiency of blue is 5 cd / A or more and 20 cd / A or less, the current efficiency of red is 30 cd / A or more and 60 cd / A or less, and the current efficiency of green is 100 cd / A or more and less than 150 cd / A. In the display device 101, a trade-off occurs between the reflectance of ambient light and the luminous efficiency depending on the polarization capability index of the corresponding part in the polarization layer 6. According to the display device 101 of this embodiment, the overall performance of the reflectance and luminous efficiency of ambient light can be improved.

[0053] [Embodiment 3] Figure 9 is a cross-sectional view showing the configuration of a display device 101 according to Embodiment 3 of the present disclosure. The second polarization capability index, the third polarization capability index, and the fourth polarization capability index may be the same as each other, for example, each may have a polarization capability index of 50%.

[0054] In the display device 101, the second part 8, the third part 9, and the fourth part 10 may each be set to an arbitrary polarization capability index, rather than being completely white. When patterning the polarization layer 6 using ultraviolet light 15, ultraviolet laser light 16, or infrared laser light 17, the irradiation time and output should be adjusted. When patterning the polarization layer 6 using water 19, the amount of water 19 dropped should be adjusted. The second polarization capability index, the third polarization capability index, and the fourth polarization capability index can each be greater than 0% and less than 100%. According to the display device 101 of this embodiment, the overall performance of the reflectance and luminous efficiency of ambient light can be improved.

[0055] [Embodiment 4] Figure 10 is a cross-sectional view showing the configuration of a display device 101 according to Embodiment 4 of the present disclosure.

[0056] The third polarization capability index may be greater than the second polarization capability index. The third polarization capability index may be 50% or more and 70% or less. In particular, when the second light-emitting element 2 emits green light, the luminous sensitivity of green light is high, so it is reasonable to increase the third polarization capability index in order to emphasize the function of the polarizing member 4.

[0057] The fourth polarization capability index may be greater than the second polarization capability index. The fourth polarization capability index may be 40% or more and 60% or less. In particular, when the third light-emitting element 3 emits red light, the luminous sensitivity of red light is between that of blue and green light, so it is reasonable to set the fourth polarization capability index to a moderate level, taking a balance between the brightness of red light and the function of the polarizing member 4.

[0058] The second polarization capability index, the third polarization capability index, and the fourth polarization capability index may be different from each other. An example is given where the first light-emitting element 1 emits blue light, the second light-emitting element 2 emits green light, and the third light-emitting element 3 emits red light. In this case, the second polarization capability index may be 30%, the third polarization capability index may be 70%, and the fourth polarization capability index may be 50%.

[0059] The display device 101 according to this embodiment can be realized by appropriately adjusting the manufacturing process so that the second polarization capability index, the third polarization capability index, and the fourth polarization capability index are different from each other. This improves the overall performance of the reflectance and luminous efficiency of ambient light.

[0060] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0061] 1. First light-emitting element 2. Second light-emitting element 3. Third light-emitting element 4. Polarizing member 5. Substrate 6. Polarizing layer 7. First part 7P: Top surface of the first part 8. Second part 8P: Top surface of the second part 78P: Boundary between the top surface of the first part and the top surface of the second part 9. Third part 10. Fourth part 11, 12, 13: Above the part where you want to lower the polarization capability index of the polarizing layer 14. Mask 15. Ultraviolet light 16. Ultraviolet laser light (laser light) 17. Infrared laser light (laser light) 18. Bank 19. Water 101. Display device

Claims

1. A display device comprising, with the observer side facing upward, a first light-emitting element and a polarizing member located above the first light-emitting element, wherein the polarizing member comprises a substrate and a polarizing layer located on the substrate, both surfaces of the substrate and both surfaces of the polarizing layer are flat, and the polarizing layer includes a first portion having a first polarization capability index of 99% or more and a second portion having a second polarization capability index of less than 99%.

2. The display device according to claim 1, wherein the polarizing layer contains iodine, and the concentration of iodine in the second portion is lower than the concentration of iodine in the first portion.

3. The display device according to claim 1 or 2, wherein, in a plan view of the display device, at least a portion of the first light-emitting element and at least a portion of the second part overlap.

4. The display device according to any one of claims 1 to 3, wherein the boundary portion between the upper surface of the first portion and the upper surface of the second portion is formed continuously and smoothly.

5. The display device according to any one of claims 1 to 3, wherein the difference between the height of the upper surface of the first part and the height of the upper surface of the second part is 100 nm or less.

6. The display device according to any one of claims 1 to 5, wherein the second polarization capability index is 50% or less.

7. The display device according to any one of claims 1 to 6, wherein the display device comprises a second light-emitting element located below the polarizing member and emitting light of a different color from the first light-emitting element, the first light-emitting element and the second light-emitting element are located horizontally, and in a plan view of the display device, at least a part of the second light-emitting element and at least a part of the first element overlap.

8. The display device according to any one of claims 1 to 6, wherein the display device comprises a second light-emitting element located below the polarizing member and emitting light of a different color from the first light-emitting element, and a third light-emitting element located below the polarizing member and emitting light of a different color from both the first and second light-emitting elements, wherein the first, second, and third light-emitting elements are located horizontally, and the polarizing layer includes a third portion having a third polarization capability index of less than 99%, and a fourth portion having a fourth polarization capability index of less than 99%, and in a plan view of the display device, at least a portion of the second light-emitting element and at least a portion of the third portion overlap, and at least a portion of the third light-emitting element and at least a portion of the fourth portion overlap.

9. The display device according to claim 8, wherein the third polarization capability index is greater than the second polarization capability index.

10. The display device according to claim 8 or 9, wherein the third polarization capability index is a polarization capability index of 50% or more and a polarization capability index of 70% or less.

11. The display device according to any one of claims 8 to 10, wherein the fourth polarization capability index is greater than the second polarization capability index.

12. The display device according to any one of claims 8 to 11, wherein the fourth polarization capability index is a polarization capability index of 40% or more and a polarization capability index of 60% or less.

13. A method for manufacturing a display device according to any one of claims 1 to 12, comprising: forming a mask such that the portion of the polarizing layer whose polarization capability index is to be reduced is exposed, and irradiating the exposed portion with ultraviolet light to form the second portion.

14. A method for manufacturing a display device according to any one of claims 1 to 12, comprising irradiating a laser beam above a portion of the polarizing layer whose polarization capability index is to be reduced to form the second portion.

15. A method for manufacturing a display device according to any one of claims 1 to 12, comprising: exposing the portion above which the polarization capability index of the polarizing layer is to be reduced, forming a bank so as to surround the exposed portion in a plan view of the display device, dropping water onto the exposed portion to form the second portion, and then removing the water.

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