Color filter substrate, display device

Abstract

Provided are a color film substrate and a display device. The color film substrate comprises: a first substrate; a color film layer disposed on the first substrate and comprising a first pattern and a second pattern, a material of the second pattern comprising quantum dots, the first pattern being configured to make excitation light pass through the first pattern to emit first color light, the second pattern being configured to make excitation light pass through the second pattern to emit second color light; and a first filter film disposed between the first substrate and the color film layer and configured to reflect part of the first color light and pass the second color light. The color film substrate can improve light efficiency.

Description

Technical Field

[0001] At least one embodiment of this disclosure relates to a color filter substrate and a display device. Background Technology

[0002] Currently, quantum dots, as a means of improving color gamut, have gradually moved from theory to application. For example, representative examples include quantum dot films provided by Fujifilm and quantum rods and quantum dot light-emitting diodes (QLEDs) provided by QD Vision. Summary of the Invention

[0003] At least one embodiment of this disclosure relates to a color filter substrate and a display device that can improve light efficiency.

[0004] At least one embodiment of this disclosure provides a color filter substrate, comprising:

[0005] First substrate;

[0006] A color filter layer, disposed on the first substrate, includes a first pattern and a second pattern. The material of the second pattern includes quantum dots. The first pattern is configured to emit a first color light after excitation light passes through the first pattern, and the second pattern is configured to emit a second color light after excitation light passes through the second pattern.

[0007] A first filter film is disposed between the first substrate and the color filter layer, and is configured to reflect a portion of the first color light and allow the second color light to pass through.

[0008] At least one embodiment of the present disclosure provides a display device, including a color filter substrate provided in at least one embodiment of the present disclosure. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure, and are not intended to limit this disclosure.

[0010] Figure 1 This is a schematic diagram of a TFT-LCD structure;

[0011] Figure 2 This is a schematic diagram of another TFT-LCD structure;

[0012] Figure 3 This is a schematic diagram of a color filter substrate and a TFT-LCD structure including the color filter substrate, provided in an embodiment of the present disclosure.

[0013] Figure 4 A schematic diagram of a color filter substrate and a TFT-LCD structure including the color filter substrate is provided for another embodiment of this disclosure;

[0014] Figure 5 A schematic diagram of a color filter substrate and a TFT-LCD structure including the color filter substrate is provided for another embodiment of this disclosure;

[0015] Figure 6 A schematic diagram of the reflectance of a TFT-LCD comprising a color filter substrate provided in the embodiments of this disclosure at different wavelengths;

[0016] Figure 7 A schematic diagram of a color filter substrate and a TFT-LCD structure including the color filter substrate is provided for another embodiment of this disclosure;

[0017] Figure 8 This is a schematic diagram of a color filter substrate and a TFT-LCD structure including the color filter substrate, provided for another embodiment of this disclosure. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0019] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0020] Figure 1 A schematic diagram of a thin-film transistor liquid crystal display (TFT-LCD) is shown. Figure 1 As shown, the TFT-LCD display device includes a color filter substrate 10, an array substrate 30, and a liquid crystal LC sandwiched between the color filter substrate 10 and the array substrate 30. The color filter substrate 10 includes a black matrix 102 and a color filter (CF) layer 103. The color filter layer 103 may include a first pattern 1031, a second pattern 1032, and a third pattern 1033. At least one of the first pattern 1031, the second pattern 1032, and the third pattern 1033 is made of a material comprising quantum dots (QDs). A backlight 401 provides a light source for the TFT-LCD display device. Excitation light passing through the first pattern 1031 emits a first color light, excitation light passing through the second pattern 1032 emits a second color light, and excitation light passing through the third pattern 1033 emits a third color light. The array substrate 30 includes a third substrate 301. A lower polarizer 302 may be disposed on the side of the array substrate 30 (third substrate 301) away from the liquid crystal LC, and an upper polarizer 122 may be disposed on the side of the color filter substrate 10 away from the LC.

[0021] from Figure 1 As can be seen, polarized light originates from the array substrate side, is initially polarized by the lower polarizer 302, and after being rotated by the liquid crystal, becomes polarized in another direction before exiting from the upper polarizer 122. However, with the use of quantum dot color filters (QD CF), the QD absorbs the incident light and re-emits it, resulting in circularly polarized light. Therefore, regardless of the liquid crystal's polarization, some light will always exit from the CF side; this is the so-called "depolarization" phenomenon.

[0022] Figure 2 A schematic diagram of another TFT-LCD structure is shown. (For example...) Figure 2 As shown, to improve depolarization, the upper polarizer can be integrated inside the display device. For example, the QD CF can be formed on the side of the upper polarizer away from the lower polarizer (i.e., light passes through the upper polarizer first, then through the color filter layer). For example, the display device may include an intermediate substrate 20, which may include a second substrate 201 and an upper polarizer 202. For example, a wire grid polarizer (WGP) can be used, which can be made very thin, enabling the integration of the upper polarizer inside the display device. However, because QD emission occurs in all directions (e.g., upward and downward), the efficiency of the QD CF is relatively low.

[0023] Figure 2 The QD CF LCD shown has a polarizer 202 mounted on the intermediate substrate 20, which can solve the depolarization problem of QD. However, the blue light that the QD does not absorb will continue to be emitted, resulting in waste and reducing the luminous efficiency of the QD. Moreover, the light emitted downward by the QD is not utilized.

[0024] like Figure 3 As shown, at least one embodiment of this disclosure provides a color filter substrate, comprising:

[0025] First substrate 101;

[0026] A color filter layer 103 is disposed on a first substrate 101 and includes a first pattern 1031 and a second pattern 1032. The material of the second pattern 1032 includes quantum dots. The first pattern 1031 is configured to emit a first color light O1 after excitation light passes through the first pattern 1031, and the second pattern 1032 is configured to emit a second color light O2 after excitation light passes through the second pattern 1032.

[0027] The first filter film 104 is disposed between the first substrate 101 and the color filter layer 103, and is configured to reflect a portion of the first color light 01 and allow the second color light 02 to pass through.

[0028] For example, the first color of light is blue light, and the second color of light is green light.

[0029] The color filter substrate provided in at least one embodiment of this disclosure allows a portion of the first color light that rises upwards after passing through the color filter layer 103 to be reflected by the first filter film 104. The reflected first color light can then be reused by the second pattern 1032, thereby improving luminous efficiency. The portion of the first color light not reflected by the first filter film 104 can pass through the first filter film 104 for display purposes. The color filter substrate provided in at least one embodiment of this disclosure can be a high-efficiency quantum dot color filter structure. The first filter film 104, while improving optical efficiency, also serves to encapsulate and protect the quantum dot (QD). For example, after the color filter substrate is provided with the first filter film 104, the contrast, brightness uniformity, and color gamut of the display device including the color filter substrate are not significantly affected.

[0030] For example, quantum dots can be incorporated into a resin (e.g., photoresist) to form a QD CF layer. The color filter substrate provided by the embodiments of this disclosure further enhances the application of process-compatible quantum dots in color gamut enhancement for panel manufacturers.

[0031] like Figure 3 As shown, according to an embodiment of the present disclosure, the color filter substrate 103 further includes a third pattern 1033. The material of the third pattern 1033 includes quantum dots. The third pattern 1033 is configured to emit a third color light 03 after the excitation light passes through it. The first filter film 104 is also configured to allow the third color light to pass through. For example, the third color light is red light. The first filter film 104 can reflect a portion of the first color light. The reflected first color light can be utilized by the third pattern, thereby improving the light efficiency.

[0032] For example, the excitation light can be provided by a backlight 401. The excitation light can have high energy to excite the quantum dots in the second and / or third patterns to emit light. For example, the excitation light can have a short wavelength, such as a wavelength shorter than the wavelengths of the second and third colors of light. For example, the wavelength of the excitation light can be less than or equal to the wavelength of the first color of light. When the wavelength of the excitation light is shorter than the wavelength of the first color of light, the first pattern can include quantum dots, and the excitation light can excite the quantum dots in the first pattern to emit light (emit the first color of light). For example, the backlight can be blue light, so that the first pattern 1031 can be formed using a transparent resin layer without adding quantum dots, thereby saving quantum dot material, but is not limited thereto. For example, the backlight wavelength can also be adjusted to add quantum dots to the first pattern 1031.

[0033] In the embodiments of this disclosure, the excitation light is described as the first color light. When the backlight 401 uses blue light, the setting of the first filter film 104 can solve the problem of incomplete absorption and transmission of QD residues of the first color light (e.g., blue light) in the second and / or third patterns, thereby improving the light efficiency.

[0034] The first filter film 104 functions to partially reflect a first color light (e.g., blue light) while allowing all second color (e.g., green light) and / or third color light (e.g., red light) to pass through. This aims to increase the number of times the first color light (e.g., blue light) excites the second and / or third patterns, thereby improving light extraction efficiency. Because blue light is too strong, partial emission is possible, and combined with red and green light, it is easy to match a white dot.

[0035] like Figure 4 As shown, according to an embodiment of the color filter substrate provided in this disclosure, the first filter film 104 may include at least two optical film layers with different refractive indices. For example, the material of each optical film layer may include SiO2. x The optical films can be made of Al₂O₃, MgF, SiNy, Ti₃O₅, ZrO₂, Nb₂O₅, or Ta₂O₅, where x and y can be any numbers greater than zero. For example, the thickness of each optical film can range from 10⁻⁶⁵ nm. For example, the refractive index of each optical film can range from 1.3 to 2.6.

[0036] like Figure 4As shown, according to an embodiment of the color filter substrate provided in this disclosure, the first filter film 104 may include at least one optical film layer group 1040. Each optical film layer group 1040 may include a first refractive index layer 10402 and a second refractive index layer 10401, wherein the refractive index of the first refractive index layer 10402 is greater than the refractive index of the second refractive index layer 10401. One or more optical film layer groups 1040 may be provided, for example, hundreds or thousands may be provided; the embodiments of this disclosure do not limit this. The first filter film 104 may be formed on a first substrate 101. For example, in each optical film layer group 1040, the first refractive index layer 10402 may be closer to the backlight than the second refractive index layer 10401. For example, in each optical film layer, the light at the refractive index change interface may undergo optical destructive or anti-reflective reactions. The interface between the first refractive index layer 10402 and the second refractive index layer 10401 may serve as a reflective interface.

[0037] Since the optical path is directly proportional to the refractive index and the thickness of the optical film, the required optical path can be obtained by adjusting the refractive index and thickness of the optical film.

[0038] like Figure 4 As shown, in a color filter substrate provided according to an embodiment of this disclosure, the refractive index of the first refractive index layer 10402 is in the range of 2.1 to 2.6, and the refractive index of the second refractive index layer 10401 is in the range of 1.3 to 1.8. For example, the material of the second refractive index layer includes SiOx, Al2O3, or MgF, and the material of the first refractive index layer includes SiNy, ZrO2, Ti3O5, Nb2O5, or Ta2O5.

[0039] like Figure 4 As shown, according to an embodiment of the present disclosure, the refractive index of the first refractive index layer 10402 can be around 2.3, and a silicon nitride film can be used. The refractive index of the second refractive index layer 10401 can be around 2.0, and a silicon nitride film can be used. That is, a double-layer silicon nitride film can be used as the first filter film 104.

[0040] like Figure 5As shown, a color filter substrate provided according to an embodiment of this disclosure includes three optical film layers 1041, 1042, and 1043. For example, in the direction from near the first substrate 101 to away from the first substrate 101, the optical film layers include a first optical film 1041, a second optical film 1042, and a third optical film 1043. The refractive index of the first optical film 1041 may be less than 2.0, the refractive index of the second optical film 1042 may be 1.45-1.5, and the refractive index of the third optical film 1043 may be greater than 2.35. For example, the first optical film 1041 and the third optical film 1043 may be SiNy films, and the second optical film 1042 may be SiOx films. The first optical film 1041 and the second optical film 1042 may form an optical film layer group 1040. For example, in the direction from near the first substrate 101 to away from the first substrate 101, the refractive index of each optical film layer may gradually increase.

[0041] like Figure 6 The figure shows the reflectance curves of the color filter substrate, including a double-layer silicon nitride film and a three-layer film structure (SiNy / SiOx / SiNy), provided in the above embodiment, at different wavelengths. Figure 6 As can be seen, in the blue light wavelength range (455nm-492nm), the reflectivity of the display device containing a double-layer silicon nitride film as the first filter film 104 is approximately 8%-14%, while the reflectivity in the green light wavelength range (492nm-577nm) and the red light wavelength range (622nm-770nm) is less than 5%. The color filter substrate provided in this embodiment can achieve the effect of reflecting blue light and transmitting green and red light.

[0042] like Figure 5 As shown, according to an embodiment of the color filter substrate provided in this disclosure, the first filter film can adopt other forms of three-layer film structure (SiNy / SiOx / SiNy). For example, the film thickness of each layer can be adjusted to achieve the effect of reflecting blue light and transmitting green and red light. Examples are shown in the table below.

[0043] Table 1. Thickness and Effect of the First Filter Membrane in a Three-Layer Membrane Structure

[0044]

[0045] In the table above, TR@450 represents the transmittance at 450nm (blue light) and TR@550 represents the transmittance at 550nm (green light). The table shows that the display device containing the first filter film 104 has a reflectance of 30%-47% at 450nm and a reflectance of less than 10% at 550nm. That is, optical films of different thicknesses can all achieve the effect of reflecting blue light and transmitting green and red light.

[0046] like Figure 7 As shown, according to an embodiment of the color filter substrate provided in this disclosure, in order to reduce the reflection of external light, a blue-violet light absorption layer 106 may also be provided on the surface opposite to where the color filter layer 103 is provided on the first substrate 101. The blue-violet light absorption layer 106 is configured to absorb blue light and ultraviolet light in the external light. For example, the blue-violet light absorption layer 106 may be fabricated according to its function, or it may be a conventional optical film layer that absorbs blue light and ultraviolet light. For example, the blue-violet light absorption layer 106 may be formed by a single layer or multiple layers, and the material of the blue-violet light absorption layer 106 may include titanium oxide. For example, the violet light absorption layer 106 has essentially no effect or little effect on the light emitted from the display device.

[0047] like Figure 8 As shown, the color filter substrate provided according to an embodiment of this disclosure further includes a second filter film 105 disposed on the color filter layer 103. The second filter film 105 is disposed on the side of the color filter layer 103 away from the first substrate 101 and is configured to allow the first color light to pass through while reflecting the second color light. For example, the second filter film 105 may also be configured to reflect the third color light. The second color light and / or the third color light that passes downward through the color filter layer 103 can be reflected by the second filter film 105, and the reflected light can be reused by the second pattern 1032 and / or the third pattern 1033. Thus, the problem of light loss when emitted downward by the QD can be solved, and the second color light and / or the third color light can be reflected back upward, effectively utilizing the light emitted downward by the QD and improving the light efficiency. The second filter film 105 not only improves the optical efficiency but also encapsulates and protects the QD. For example, as described above, the first color light is blue light, the second color light is green light, and the third color light is red light.

[0048] For example, the second filter film 105 can be made according to its function, for example, it can be a conventional optical film layer that absorbs blue light and reflects green and red light.

[0049] At least one embodiment of this disclosure provides a display device, such as Figure 3-5 As shown in any of 7-8, any color filter substrate 10 provided in at least one embodiment of the present disclosure.

[0050] It should be noted that in the display device provided in the embodiments of this disclosure, according to at least one embodiment of the display device provided in this disclosure, the second filter film 105 may not be disposed on the first substrate 101, but on the second substrate 201, thereby the intermediate substrate 20 can serve as the filter substrate. Thus, the filter substrate includes the second substrate 201 and an upper polarizer 202 and a second filter film 105 disposed on the second substrate 201. The second filter film 105 is configured to transmit first color light and reflect second color light. For example, the second filter film 105 may also be configured to reflect third color light.

[0051] For example, the display device can be any product or component with display function, such as a liquid crystal display panel, electronic paper, OLED panel, mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0052] For example, the first substrate 101 and the third substrate 103 may be glass substrates, but are not limited thereto. The second substrate 102 may be a glass substrate or a flexible substrate, but is not limited thereto.

[0053] In the embodiments disclosed herein, blue light is used as the first color, green light as the second color, and red light as the third color, but the description is not limited thereto. The quantum dots included in the color filter layer can be fabricated using common materials and common methods. Optical films with different refractive indices can be fabricated by adjusting the fabrication process. The same material can have different refractive indices under different fabrication processes. The fabrication of the optical film layer can refer to common designs. The quantum dot color filter layer and the metal mesh polarizer can be fabricated using common processes.

[0054] The following points need to be explained:

[0055] (1) Unless otherwise defined, the same reference numerals in the embodiments of this disclosure and the accompanying drawings have the same meaning.

[0056] (2) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.

[0057] (3) For clarity, the thickness of layers or regions is magnified in the drawings used to describe embodiments of the present disclosure. It will be understood that when an element such as a layer, film, region or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element, or there may be intermediate elements present.

[0058] (4) Where there is no conflict, features of the same embodiment and different embodiments of this disclosure may be combined with each other.

[0059] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A color filter substrate, comprising: First substrate; A color filter layer, disposed on the first substrate, includes a first pattern and a second pattern. The material of the second pattern includes quantum dots. The first pattern is configured to emit a first color light after excitation light passes through the first pattern, and the second pattern is configured to emit a second color light after the excitation light passes through the second pattern. A first filter film is disposed between the first substrate and the color filter layer, and is configured to reflect a portion of the first color light and allow the second color light to pass through.

2. The color filter substrate according to claim 1, wherein, The first filter film comprises at least two optical film layers with different refractive indices.

3. The color filter substrate according to claim 2, wherein, The materials of each optical film layer include SiO x Al2O3, MgF, SiNy, Ti3O5, ZrO2, Nb2O5 or Ta2O5.

4. The color filter substrate according to claim 2, wherein, The refractive index of each optical film layer ranges from 1.3 to 2.

6.

5. The color filter substrate according to claim 2, wherein, The thickness of each optical film layer ranges from 10 to 65 nm.

6. The color filter substrate according to claim 1, wherein, The first filter film includes at least one optical film layer group, the optical film layer group including a first refractive index layer and a second refractive index layer, wherein the refractive index of the first refractive index layer is greater than the refractive index of the second refractive index layer.

7. The color filter substrate according to claim 6, wherein, The refractive index of the first refractive index layer is in the range of 2.1 to 2.6, and the refractive index of the second refractive index layer is in the range of 1.3 to 1.

8.

8. The color filter substrate according to claim 6, wherein, The first refractive index layer material includes SiNy, ZrO2, Ti3O5, Nb2O5 or Ta2O5, and the second refractive index layer material includes SiOx, Al2O3 or MgF.

9. The color filter substrate according to claim 2, wherein, The refractive index of the optical film gradually increases from the direction closest to the first substrate to the direction furthest from the first substrate.

10. The color filter substrate according to any one of claims 1-9, wherein, The color filter layer further includes a third pattern, the material of which includes quantum dots, and the third pattern is configured to cause the excitation light to emit a third color light after passing through the third pattern. The first filter film is also configured to allow the third color light to pass through.

11. The color filter substrate according to claim 10, wherein, The first color light is blue light, the second color light is green light, and the third color light is red light.

12. The color filter substrate according to any one of claims 1-9, wherein a blue-violet light absorption layer is further provided on the surface of the first substrate away from the color filter layer, wherein, The blue-violet light absorption layer is configured to absorb blue light and ultraviolet light from the ambient light.

13. The color filter substrate according to any one of claims 1-9, further comprising a second filter film disposed on the color filter layer, wherein, The second filter film is disposed on the side of the color filter layer away from the first substrate and is configured to transmit the first color light and reflect the second color light.

14. The color filter substrate according to claim 13, wherein, The second filter is also configured to reflect a third color of light.

15. A display device comprising a color filter substrate as described in any one of claims 1-14.

16. A display device comprising a filter substrate and a display panel according to any one of claims 1-12, wherein, The filter substrate is disposed on the side of the color filter layer away from the first substrate, and includes a second substrate and a second filter film thereon, wherein the second filter film is configured to transmit the first color light and reflect the second color light.

17. The display panel according to claim 16, wherein, The second filter is also configured to reflect a third color of light.

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