Display device

Abstract

A display device includes a driving backplane, a bank layer, a first light emitting element, a first lower optical structure, and a first color conversion structure. The bank layer is arranged on the driving backboard and is provided with a first opening. The first light-emitting element is located in the first opening and electrically connected to the driving backboard. The first lower optical structure is disposed in the first opening of the bank layer and covers the first light-emitting element. The first color conversion structure is disposed in the first opening of the bank layer and on the first lower optical structure. The first lower optical structure is located between the first color conversion structure and the first light-emitting element. The first light-emitting element is used for emitting first colored light. The first color conversion structure is used for converting the first color light into second color light. The first lower optical structure is used for penetrating the first colored light and reflecting the second colored light.

Description

Technical Field

[0001] The present invention relates to a display device. Background Art

[0002] A light-emitting diode display panel includes a driving backplane and a plurality of light-emitting diode elements disposed on the driving backplane. Inheriting the characteristics of light-emitting diodes, the light-emitting diode display panel has advantages such as power saving, high efficiency, high brightness, and fast response time. In addition, compared with an organic light-emitting diode display panel, the light-emitting diode display panel also has advantages such as easy color calibration, long luminous life, and no image burn-in. Therefore, the light-emitting diode display panel is regarded as the next-generation display technology.

[0003] In a light-emitting diode display panel with a current architecture, the light-emitting diode elements can be paired with a color conversion structure to emit a display beam with a desired color. However, when the excitation beam emitted by the light-emitting diode elements is transmitted to the color conversion structure to convert a display beam with a desired color, part of the display beam is easily trapped inside the light-emitting diode display panel and cannot emit light, resulting in low optical efficiency of the light-emitting diode display panel. Summary of the Invention

[0004] The present invention provides a display device with good optical efficiency.

[0005] The display device of the present invention includes a driving backplane, a bank layer, a first light-emitting element, a second light-emitting element, a third light-emitting element, a counter substrate, a first lower optical structure, and a first color conversion structure. The bank layer is disposed on the driving backplane and has a first opening, a second opening, and a third opening. The first light-emitting element, the second light-emitting element, and the third light-emitting element are located in the first opening, the second opening, and the third opening and are electrically connected to the driving backplane. The counter substrate is disposed opposite to the driving backplane. The first lower optical structure is disposed in the first opening of the bank layer and covers the first light-emitting element. The first color conversion structure is disposed in the first opening of the bank layer and on the first lower optical structure. The first lower optical structure is located between the first color conversion structure and the first light-emitting element. The first light-emitting element is used to emit a first color light. The first color conversion structure is used to convert the first color light into a second color light. The first lower optical structure is used to allow the first color light to penetrate and reflect the second color light. Brief Description of the Drawings

[0006] Figure 1 It is a schematic cross-sectional view of a display device according to an embodiment of the present invention.

[0007] Figure 2 Schematically illustrate a first light-emitting element, a first lower optical structure, a first color conversion structure, a first upper optical structure, a first color light emitted by the first light-emitting element, and a second color light converted by the first color conversion structure of the display device according to an embodiment of the present invention.

[0008] Figure 3 Schematic cross-sectional view of a display device according to another embodiment of the present invention.

[0009] Figure 4 Schematic cross-sectional view of a display device according to yet another embodiment of the present invention.

[0010] Figure 5 Schematic cross-sectional view of a display device according to still another embodiment of the present invention.

[0011] Description of reference numerals:

[0012] 10, 10A, 10B, 10C: Display device

[0013] 110: Driving backplane

[0014] 120: Bank layer

[0015] 121: First opening

[0016] 122: Second opening

[0017] 123: Third opening

[0018] 131: First light-emitting element

[0019] 131a: Top surface

[0020] 131b: Side wall

[0021] 132, 132C: Second light-emitting element

[0022] 133: Third light-emitting element

[0023] 140: Opposing substrate

[0024] 142: Substrate

[0025] 144: Light-shielding pattern layer

[0026] 144a: Opening

[0027] 146R, 146G, 146B: Color filter pattern

[0028] 151: First lower optical structure

[0029] 152: Second lower optical structure

[0030] 161: First color conversion structure

[0031] 162: Second color conversion structure

[0032] 171: First upper optical structure

[0033] 172: Second upper optical structure

[0034] 180, 190, 192: Transparent materials

[0035] L1: First color light

[0036] L1a: Another part

[0037] L2, L2': Second color light

[0038] L2a: First part

[0039] L2b: Second part

[0040] PX: Pixel

[0041] SW1, SW2: Sandwich structure

[0042] T151, T152, T171, T172: Thickness

[0043] z: Direction Detailed implementation manners

[0044] Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0045] It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, no intervening elements are present. As used herein, "connected" can refer to physical and / or electrical connection. Furthermore, "electrically connected" or "coupled" can mean that there are other elements between two elements.

[0046] As used herein, "about", "approximate", or "substantially" includes the stated value and the average within an acceptable deviation range of a particular value determined by a person of ordinary skill in the art, taking into account the particular amount of the measurement and the errors associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within ±30%, ±20%, ±10%, ±5%. Furthermore, "about", "approximate", or "substantially" as used herein can be selected according to optical properties, etching properties, or other properties to a more acceptable deviation range or standard deviation, rather than using one standard deviation to apply to all properties.

[0047] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this invention, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0048] Figure 1 It is a schematic cross-sectional view of a display device according to an embodiment of the present invention. Figure 1 Taking a pixel PX of the display device 10 as a representative is drawn. Those skilled in the art can implement the entire display device 10 according to Figure 1 and the following description, and thus multiple pixels PX will not be repeatedly shown here.

[0049] Please refer to Figure 1 , the display device 10 includes a driving backplane 110. The driving backplane 110 may include a plurality of sub-pixel driving circuits (not shown). For example, in one embodiment, each sub-pixel driving circuit may include a first transistor (not shown), a second transistor (not shown), and a capacitor (not shown), wherein a first end of the first transistor is electrically connected to a corresponding data line (not shown), a control end of the first transistor is electrically connected to a corresponding scan line (not shown), a second end of the first transistor is electrically connected to a control end of the second transistor, a first end of the second transistor is electrically connected to a corresponding power supply line (not shown), and the capacitor is electrically connected to the second end of the first transistor and the first end of the second transistor. However, the present invention is not limited thereto, and in other embodiments, the sub-pixel driving circuit may also be in other forms.

[0050] The display device 10 further includes a bank layer 120 disposed on the driving backplane 110. The bank layer 120 has a first opening 121, a second opening 122, and a third opening 123. In some embodiments, the material of the bank layer 120 may selectively have reflectivity, but the present invention is not limited thereto.

[0051] The display device 10 further includes a first light-emitting element 131, a second light-emitting element 132, and a third light-emitting element 133. The first light-emitting element 131, the second light-emitting element 132, and the third light-emitting element 133 are respectively located in the first opening 121, the second opening 122, and the third opening 123 of the bank layer 120. The first light-emitting element 131, the second light-emitting element 132, and the third light-emitting element 133 are respectively electrically connected to a plurality of sub-pixel driving circuits of the driving backplane 110.

[0052] The first light-emitting element 131, the second light-emitting element 132, and the third light-emitting element 133 are respectively configured to emit a first color light, a third color light, and a fifth color light. For example, in some embodiments, the first color light, the third color light, and the fifth color light are respectively blue light, green light, and blue light, but the present invention is not limited thereto. In some embodiments, the first light-emitting element 131, the second light-emitting element 132, and the third light-emitting element 133 are, for example, multiple light-emitting diodes (LEDs). However, the present invention is not limited thereto. In other embodiments, the first light-emitting element 131, the second light-emitting element 132, and the third light-emitting element 133 may also be other types of light-emitting elements, such as but not limited to: organic electroluminescent elements, etc.

[0053] The display device 10 further includes a counter substrate 140 disposed opposite to the driving backplane 110. In some embodiments, the counter substrate 140 may include a substrate 142, a light-shielding pattern layer 144 disposed on the substrate 142, and multiple color filter patterns 146R, 146G, 146B respectively disposed in multiple openings 144a of the light-shielding pattern layer 144. In some embodiments, the substrate 142 may be a light-transmissive substrate, and the material of the light-transmissive substrate is, for example, glass, quartz, organic polymer, or other applicable materials. In some embodiments, the light-shielding pattern layer 144 may be a black matrix, and the material of the black matrix is, for example, black resin or other applicable materials. The multiple color filter patterns 146R, 146G, 146B have different colors. For example, in some embodiments, each pixel PX of the display device 10 may include multiple color filter patterns 146R, 146G, 146B respectively having red, green, and blue colors, but the present invention is not limited thereto.

[0054] Each pixel PX of the display device 10 further includes a first lower optical structure 151 disposed in the first opening 121 of the bank layer 120 and covering the first light-emitting element 131. Specifically, in some embodiments, the first lower optical structure 151 may cover the top surface 131a and the side wall 131b of the first light-emitting element 131.

[0055] Each pixel PX of the display device 10 further includes a first color conversion structure 161 disposed in the first opening 121 of the bank layer 120 and on the first lower optical structure 151. The first lower optical structure 151 is located between the first color conversion structure 161 and the first light-emitting element 131. The first color conversion structure 161 is located between the counter substrate 140 and the first lower optical structure 151. The first color conversion structure 161 is configured to convert the first color light emitted by the first light-emitting element 131 into a second color light. For example, in some embodiments, the first color conversion structure 161 is configured to convert the blue light emitted by the first light-emitting element 131 into red light, but the present invention is not limited thereto.

[0056] In some embodiments, each pixel PX of the display device 10 further includes a first upper optical structure 171 disposed in the first opening 121 of the bank layer 120 and on the first color conversion structure 161. The first color conversion structure 161 is located between the first upper optical structure 171 and the first lower optical structure 151. The first upper optical structure 171 is located between the opposing substrate 140 and the first color conversion structure 161. In some embodiments, the thickness T151 of the first lower optical structure 151 in the direction z perpendicular to the driving backplane 110 may be greater than the thickness T171 of the first upper optical structure 171 in the direction z, but the present invention is not limited thereto.

[0057] In some embodiments, each pixel PX of the display device 10 may further include a light-transmissive material 180 disposed in the second opening 122 of the bank layer 120 and covering the second light-emitting element 132. The light-transmissive material 180 is located between the opposing substrate 140 and the second light-emitting element 132. In some embodiments, the second light-emitting element 132 is configured to emit a third color light (not shown), and the third color light can pass through the light-transmissive material 180 and substantially does not change its color. For example, in some embodiments, the light-transmissive material 180 may include a transparent photoresist or a transparent planarization layer, but the present invention is not limited thereto. In some embodiments, a plurality of scattering particles may be selectively incorporated into the light-transmissive material 180, but the present invention is not limited thereto.

[0058] In some embodiments, each pixel PX of the display device 10 may further include a light-transmissive material 190 disposed in the third opening 123 of the bank layer 120 and covering the third light-emitting element 133. The light-transmissive material 190 is located between the opposing substrate 140 and the third light-emitting element 133. In some embodiments, the third light-emitting element 133 is configured to emit a fifth color light (not shown), and the fifth color light can pass through the light-transmissive material 190 and substantially does not change its color. For example, in some embodiments, the light-transmissive material 190 may include a transparent photoresist or a transparent planarization layer, but the present invention is not limited thereto. In some embodiments, a plurality of scattering particles may be selectively incorporated into the light-transmissive material 190, but the present invention is not limited thereto.

[0059] Figure 2 Schematically illustrated are a first light-emitting element, a first lower optical structure, a first color conversion structure, a first upper optical structure, a first color light emitted by the first light-emitting element, and a second color light converted by the first color conversion structure of a display device according to an embodiment of the present invention.

[0060] Please refer to Figure 1 and Figure 2It should be noted that the first light-emitting element 131 is configured to emit a first color light L1, the first color conversion structure 161 is configured to convert the first color light L1 into a second color light L2, the first lower optical structure 151 is configured to allow the first color light L1 to penetrate and reflect the second color light L2, and the first upper optical structure 171 is configured to allow the second color light L2 to penetrate and reflect the first color light L1.

[0061] Specifically, the first color light L1 emitted by the first light-emitting element 131 can penetrate the first lower optical structure 151 and be transmitted to the first color conversion structure 161. A part (not shown) of the first color light L1 can be converted into the second color light L2 by the first color conversion structure 161. The second color light L2 includes a first part L2a and a second part L2b, wherein the first part L2a is transmitted substantially toward the driving backplane 110, and the second part L2b is transmitted substantially toward the counter substrate 140. The second part L2b of the second color light L2 can pass through the first upper optical structure 171 and then exit. The first part L2a of the second color light L2 can be reflected back into the first color conversion structure 161 by the first lower optical structure 151, and then pass through the first upper optical structure 171 and exit. That is to say, through the reflection of the first lower optical structure 151, the emission probability of the second part L2b of the second color light L2, which was originally likely to be trapped inside the display device 10, can be greatly increased. Therefore, the optical efficiency of the display device 10 can be significantly improved.

[0062] On the other hand, another part L1a of the first color light L1 transmitted to the first color conversion structure 161 may not be converted into the second color light L2 and continue to be transmitted toward the counter substrate 140. In some embodiments, another part L1a of the first color light L1 can be reflected back into the first color conversion structure 161 by the first upper optical structure 171, and then reused by the first color conversion structure 161 to convert the second color light L2'. The second color light L2' can pass through the first upper optical structure 171 and then exit. That is to say, the first upper optical structure 171 helps to recover another part L1a of the first color light L1 that is not fully utilized by the first color conversion structure 161, increases the probability that another part L1a of the first color light L1 is converted into the second color light L2', and thereby improves the optical efficiency of the display device 10. At the same time, the amount of the first color light L1 emitted by the first light-emitting element 131 leaking out of the display device 10 can also be reduced, thereby improving the color purity of the display device 10.

[0063] Briefly, in some embodiments, the first color conversion structure 161 is sandwiched between the first upper optical structure 171 and the first lower optical structure 151. Utilizing the sandwich structure SW1 formed by the first color conversion structure 161, the first upper optical structure 171, and the first lower optical structure 151, and the optical characteristics of the first upper optical structure 171 and the first lower optical structure 151, an optical resonance cavity effect can be achieved, enabling the internal light to be continuously recycled and reused. Therefore, the optical efficiency of the display device 10 can be significantly improved.

[0064] In some embodiments, the first lower optical structure 151 can allow a blue light to penetrate and reflect a red light, and the first upper optical structure 171 can allow a red light to penetrate and reflect a blue light. In some embodiments, preferably, the transmittance of the first lower optical structure 151 to the blue light can be greater than 90%, the reflectance of the first lower optical structure 151 to the red light can be greater than 80%, the transmittance of the first upper optical structure 171 to the red light can be greater than 90%, and the reflectance of the first upper optical structure 171 to the blue light can be greater than 80%, but the present invention is not limited thereto.

[0065] It must be noted here that the following embodiments follow the component numbers and some contents of the foregoing embodiments, where the same numbers are used to represent the same or similar components, and the description of the same technical content is omitted. For the description of the omitted parts, reference can be made to the foregoing embodiments, and the following embodiments will not be repeated.

[0066] Figure 3 It is a schematic cross-sectional view of a display device according to another embodiment of the present invention. Figure 3 The display device 10A and Figure 1 The display device 10 are similar, and the difference between the two is that: Figure 3 The display device 10A does not include Figure 1 The first lower optical structure 151 but includes a light-transmitting material 192. Please refer to Figure 3 , the light-transmitting material 192 is disposed in the first opening 121 of the bank layer 120 and covers the first light-emitting element 131. The light-transmitting material 192 is located between the first color conversion structure 161 and the driving backplane 110. For example, in some embodiments, the light-transmitting material 192 may include a transparent photoresist or a transparent planarization layer, but the present invention is not limited thereto. Figure 3 Although the display device 10A does not include Figure 1 The first lower optical structure 151, the optical efficiency of the display device 10A can still be improved through the first upper optical structure 171.

[0067] Figure 4 It is a schematic cross-sectional view of a display device according to still another embodiment of the present invention. Figure 4 The display device 10B and Figure 1 The display device 10 are similar, and the difference between the two is that:Figure 4 The display device 10B does not include Figure 1 the first upper optical structure 171. Figure 4 Although the display device 10B does not include Figure 1 the first upper optical structure 171, the optical efficiency of the display device 10B can still be improved by the first lower optical structure 151.

[0068] Figure 5 It is a cross-sectional schematic view of the display device according to another embodiment of the present invention. Figure 5 The display device 10C is similar to Figure 1 the display device 10, and the difference between the two is that: Figure 5 the display device 10C does not include Figure 1 the light-transmitting material 180 but includes a second lower optical structure 152, a second color conversion structure 162, and a second upper optical structure 172.

[0069] Please refer to Figure 5 , the second lower optical structure 152 is disposed in the second opening 122 of the bank layer 120 and covers the second light-emitting element 132C. The second color conversion structure 162 is disposed in the second opening 122 of the bank layer 120 and on the second lower optical structure 152. The second lower optical structure 152 is located between the second color conversion structure 162 and the second light-emitting element 132C. The second light-emitting element 132C is used to emit a third color light (for example: blue light). The second color conversion structure 162 is used to convert the third color light (for example: blue light) into a fourth color light (for example: green light). The second lower optical structure 152 is used to make the third color light (for example: blue light) penetrate and reflect the fourth color light (for example: green light).

[0070] The second upper optical structure 172 is disposed in the second opening 122 of the bank layer 120 and on the second color conversion structure 162. The second color conversion structure 162 is located between the second upper optical structure 172 and the second lower optical structure 152. The second upper optical structure 172 is located between the counter substrate 140 and the second color conversion structure 162. The second upper optical structure 172 is used to make the fourth color light (for example: green light) penetrate and reflect the third color light (for example: blue light).

[0071] Similarly, by using the sandwich structure SW2 formed by the second color conversion structure 162, the second upper optical structure 172, and the second lower optical structure 152 and matching the optical characteristics of the second upper optical structure 172 and the second lower optical structure 152, the optical resonance cavity effect can be achieved, so that the internal light is continuously recycled and reused. Therefore, the optical efficiency of the display device 10C can be greatly improved.

[0072] In some embodiments, the second lower optical structure 152 is configured to allow blue light to penetrate and reflect green light, and the second upper optical structure 172 is configured to allow green light to penetrate and reflect blue light. In some embodiments, preferably, the transmittance of the second lower optical structure 152 to blue light is greater than 90%, and the reflectance of the second lower optical structure 152 to green light is greater than 80%, but the present invention is not limited thereto. In some embodiments, preferably, the transmittance of the second upper optical structure 172 to green light is greater than 90%, and the reflectance of the second upper optical structure 172 to blue light is greater than 80%, but the present invention is not limited thereto. In some embodiments, the thickness T152 of the second lower optical structure 152 in the direction z perpendicular to the driving backplane 110 may be greater than the thickness T172 of the second upper optical structure 172 in the direction z, but the present invention is not limited thereto.

Claims

1. A display device, comprising: a driving backplane; a bank layer disposed on the driving backplane and having a first opening, a second opening, and a third opening; a first light-emitting element, a second light-emitting element, and a third light-emitting element located in the first opening, the second opening, and the third opening, respectively, and electrically connected to the driving backplane; a counter substrate disposed opposite to the driving backplane; a first lower optical structure disposed in the first opening of the bank layer and covering the first light-emitting element; and a first color conversion structure disposed in the first opening of the bank layer and on the first lower optical structure, wherein the first lower optical structure is located between the first color conversion structure and the first light-emitting element, the first light-emitting element is configured to emit a first color light, the first color conversion structure is configured to convert the first color light into a second color light, and the first lower optical structure is configured to allow the first color light to penetrate and reflect the second color light.

2. The display device according to claim 1, further comprising: a first upper optical structure disposed in the first opening of the bank layer and on the first color conversion structure, wherein the first color conversion structure is located between the first upper optical structure and the first lower optical structure, the first upper optical structure is located between the counter substrate and the first color conversion structure, and the first upper optical structure is configured to allow the second color light to penetrate and reflect the first color light.

3. The display device according to claim 2, wherein the first lower optical structure is configured to allow a blue light to penetrate and reflect a red light, and the first upper optical structure is configured to allow the red light to penetrate and reflect the blue light.

4. The display device according to claim 3, wherein the first lower optical structure has a transmittance of the blue light greater than 90%, and a reflectance of the red light greater than 80%.

5. The display device according to claim 3, wherein the first upper optical structure has a transmittance of the red light greater than 90%, and a reflectance of the blue light greater than 80%.

6. The display device according to claim 1, further comprising: a second lower optical structure disposed in the second opening of the bank layer and covering the second light-emitting element; and a second color conversion structure disposed in the second opening of the bank layer and on the second lower optical structure, wherein the second lower optical structure is located between the second color conversion structure and the second light-emitting element, the second light-emitting element is configured to emit a third color light, the second color conversion structure is configured to convert the third color light into a fourth color light, and the second lower optical structure is configured to allow the third color light to penetrate and reflect the fourth color light.

7. The display device according to claim 6, further comprising: a second upper optical structure disposed in the second opening of the bank layer and on the second color conversion structure, wherein the second color conversion structure is located between the second upper optical structure and the second lower optical structure, the second upper optical structure is located between the counter substrate and the second color conversion structure, and the second upper optical structure is configured to allow the fourth color light to penetrate and reflect the third color light.

8. The display device according to claim 7, wherein the second lower optical structure is configured to allow a blue light to penetrate and reflect a green light, and the second upper optical structure is configured to allow the green light to penetrate and reflect the blue light.

9. The display device according to claim 8, wherein a transmittance of the second lower optical structure for the blue light is greater than 90%, and a reflectance of the second lower optical structure for the green light is greater than 80%.

10. The display device according to claim 8, wherein a transmittance of the second upper optical structure for the green light is greater than 90%, and a reflectance of the second upper optical structure for the blue light is greater than 80%.

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