Liquid crystal display

Abstract

The invention provides a liquid crystal display. The liquid crystal display comprises a backlight module, a reflection filter film and a wavelength conversion film. The backlight module comprises a plurality of light-emitting diodes, and each light-emitting diode can emit a first light ray. The reflective filter film is disposed on one side of the backlight module to receive the first light. The reflective filter film has the following spectral characteristics. The reflective filter film allows at least part of light in a first wavelength range to penetrate; the first wavelength ranges from 370 nanometers to 450 nanometers. The reflection filter film can at least partially block light rays in the second wavelength range from penetrating and reflect the light rays in the second wavelength range; the second wavelength ranges from 450 nanometers to 900 nanometers. The wavelength conversion film is arranged on the side, away from the backlight module, of the reflection filter film, and the wavelength conversion film can conduct optical wavelength conversion on the first light to form second light. Therefore, the utilization efficiency of the light source is greatly improved, the condition of light loss is avoided, and the image display brightness is improved under the condition of lower power consumption.

Description

Technical Field

[0001] This application relates to a display, and more particularly to a liquid crystal display. Background Technology

[0002] In the prior art, the light source of a liquid crystal display can be divided into edge-lit LED backlights and direct-lit LED backlights.

[0003] For example, please see Figure 1 and 2 As shown, an existing liquid crystal display R based on a direct-lit LED backlight includes: a backlight module R1, an optical film R2 (such as a diffuser film, diffuser sheet, or prism sheet) disposed on the backlight module R1, and a liquid crystal display panel R3 disposed on the optical film R2, which may include, for example: a lower polarizer R31, a lower alignment film (not shown), a liquid crystal layer R32, and an upper alignment film, a color filter, and an upper polarizer (not shown).

[0004] The backlight module R1 includes a light source array formed by multiple light-emitting diodes R11 (LEDs) spaced apart, and a reflective film R12 disposed between the multiple LEDs R11 to cover the area between the multiple LEDs R11 (e.g., Figure 2 To avoid light leakage.

[0005] The light emitted by the aforementioned light-emitting diode R11 includes P-polarized light and N-polarized light. The P-polarized light can penetrate the optical film R2 (such as a diffusion film) and the lower polarizer R31 of the liquid crystal display panel R3 and travel in the direction of the liquid crystal layer R32.

[0006] Furthermore, in the light emitted by the aforementioned light-emitting diode R11, the N-polarized light passes through the optical film R2 and is reflected when it encounters the lower polarizer R31. After being reflected, if the N-polarized light encounters the reflective film R12, it will be reflected again to the lower polarizer R31, thus having the opportunity to pass through the lower polarizer R31 and be transmitted out.

[0007] However, if the N-polarized light is reflected and encounters the light-emitting diode R11 instead of the reflective film R12, it will not be reflected and will dissipate in the backlight module R1. As a result, the light emitted by the light source array of the light-emitting diode R11 (LED) in the backlight module R1 cannot completely pass through the lower polarizer R31 and travel towards the liquid crystal layer R32, leading to poor light utilization (e.g., reduced brightness of the displayed image and increased energy consumption).

[0008] Based on the current backlight evolution trend, it is from the cold cathode fluorescent lamp CCFL, light emitting diode LED, to the mini LED (i.e. sub-millimeter light emitting diode) direction, and the arrangement density between mini LEDs will be higher and higher, resulting in that if the existing architecture is used for design, the area covered by the reflective film sheet R12 of the backlight module R1 will be greatly reduced, and the light utilization rate of the backlight module will be greatly reduced, which reduces the image brightness output by the liquid crystal display, and makes it not conducive to compete with the liquid crystal display based on the side light type light emitting diode (LED) backlight architecture in the market.

[0009] In summary, the applicant feels that the above-mentioned deficiencies can be improved, and after careful research and application of the theory, the present application is finally proposed, which is a design that reasonably and effectively improves the above-mentioned deficiencies. SUMMARY

[0010] The technical problem to be solved by the present application is to provide a liquid crystal display that can greatly improve the light source utilization efficiency, effectively avoid light loss, and improve the image display brightness under the condition of low power consumption.

[0011] In order to solve the above technical problems, one of the technical solutions adopted by the present application is to provide a liquid crystal display, which comprises: a backlight module comprising a plurality of light emitting diodes arranged at intervals, and each light emitting diode can emit a first light; a reflective filter film is arranged on one side of the backlight module to receive the first light; wherein the reflective filter film has the following spectral characteristics: the reflective filter film can allow at least part of the light in a first wavelength range to penetrate; wherein the first wavelength range is between 370 nanometers and 450 nanometers; the reflective filter film can at least partially block the light in a second wavelength range from penetrating, and reflect the light in the second wavelength range; wherein the second wavelength range is between 450 nanometers and 900 nanometers; and a wavelength conversion film is arranged on the side of the reflective filter film away from the backlight module, and the wavelength conversion film can convert the wavelength of the first light to form a second light.

[0012] Optionally, the reflective filter film has a first light transmittance for the light in the first wavelength range, and a second light transmittance for the light in the second wavelength range, and the first light transmittance is greater than the second light transmittance.

[0013] Optionally, in the spectral characteristics of the reflective filter film, the first wavelength range is between 370 nanometers and 425 nanometers, and the second wavelength range is between 450 nanometers and 850 nanometers.

[0014] Optionally, the first light transmittance is not less than 50%, and the second light transmittance is not more than 25%.

[0015] Optionally, each of the light emitting diodes is a mini light emitting diode (mini LED), and the first light emitted by each of the light emitting diodes has a first light wavelength of 370-450 nm, and the second light formed by the wavelength conversion film has a second light wavelength of 450-900 nm.

[0016] Optionally, the reflective filter film completely covers the light emitting diodes of the backlight module.

[0017] Optionally, the liquid crystal display further comprises: an optical film disposed on a side of the wavelength conversion film away from the reflective filter film, for providing the second light to pass through; wherein the optical film is at least one of a light diffusion film, a light condensing film, and a prism film; and a polarizing film disposed on a side of the optical film away from the wavelength conversion film; wherein the polarizing film is a reflective polarizing film, and the polarizing film allows a P-polarized light in the second light to pass through, and reflects an N-polarized light in the second light.

[0018] Optionally, after the polarizing film reflects the N-polarized light in the second light, the N-polarized light can pass through the optical film and the wavelength conversion film in sequence along a reflection path, and then irradiate to the reflective filter film, and then the reflective filter film reflects the N-polarized light again to irradiate to the polarizing film again along another reflection path.

[0019] Optionally, the reflective filter film is formed by stacking multiple layers of inorganic film layers or polymer film layers with different refractive indexes.

[0020] Optionally, the wavelength conversion film is a quantum dot film.

[0021] The beneficial effects of this application are that the liquid crystal display provided by this application can significantly improve the light source utilization efficiency, effectively avoid light loss, and improve the brightness of image display under low power consumption conditions by using the technical solutions of "a reflective filter film disposed on one side of the backlight module to receive the first light; wherein the reflective filter film has the following spectral characteristics: the reflective filter film can allow light of a first wavelength range to at least partially pass through; wherein the first wavelength range is between 370 nm and 450 nm; the reflective filter film can at least partially block light of a second wavelength range from passing through and reflect the light of the second wavelength range; wherein the second wavelength range is between 450 nm and 900 nm" and "a wavelength conversion film disposed on the side of the reflective filter film away from the backlight module, and the wavelength conversion film can convert the wavelength of the first light to form a second light".

[0022] The other effects and embodiments of this application are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the architecture of a liquid crystal display in the prior art;

[0025] Figure 2 A schematic diagram illustrating the arrangement of reflective films in existing backlight modules;

[0026] Figure 3 This is a schematic diagram of the architecture of a liquid crystal display according to an embodiment of this application;

[0027] Figure 4 for Figure 3 A schematic diagram of the light path emitted by the backlight module of a display;

[0028] Figure 5 for Figure 3 A schematic diagram of the spectral characteristics of the light emitted by the backlight module of a display. Detailed Implementation

[0029] The following specific embodiments illustrate the implementation methods of the "liquid crystal display" disclosed in this application. Those skilled in the art can understand the advantages and effects of this application from the content disclosed in this specification. This application can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this application. Furthermore, the accompanying drawings are for simple illustration only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of this application in detail, but the disclosed content is not intended to limit the scope of protection of this application.

[0030] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0031] Please see Figures 3 to 5 As shown, this application provides a liquid crystal display E, which includes at least a backlight module 1, a reflective filter 2, and a wavelength conversion film 3. In this embodiment, the liquid crystal display E further includes an optical film 4 and a polarizing film 5, and selectively includes other functional layers of the liquid crystal display panel, such as upper and lower alignment films, a liquid crystal layer, and a color filter, but this application is not limited thereto.

[0032] The backlight module 1 includes a plurality of light-emitting diodes 11, which are arranged at intervals to form a light source array. In some embodiments of this application, each light-emitting diode 11 is a sub-millimeter light-emitting diode (i.e., mini LED) or a direct-lit light-emitting diode (i.e., direct-lit LED), but this application is not limited thereto.

[0033] For example, in other embodiments of this application, the light-emitting diode 11 may also be a conventional light-emitting diode (LED) or a micro light-emitting diode (Micro LED).

[0034] Optionally, each of the light-emitting diodes 11 is a sub-millimeter light-emitting diode with a die size of approximately 100 micrometers to 200 micrometers. Furthermore, the spacing between any two adjacent light-emitting diodes 11 is approximately 100 micrometers to 300 micrometers, and in this embodiment, no reflective film is disposed between any two adjacent light-emitting diodes 11, but this application is not limited thereto.

[0035] Further, each of the light emitting diodes 11 is configured to emit a first light L1, and the first light L1 has a first light wavelength between 370 nm and 450 nm. That is, the first light L1 appears as blue light or violet light.

[0036] Please continue to refer to Figures 3 to 5 The reflective filter film 2 is disposed on a side surface of the backlight module 1 and completely covers the light emitting diodes 11 of the backlight module 1, so that the light emitted by each of the light emitting diodes 11 is irradiated to the reflective filter film 2.

[0037] In the embodiment, the reflective filter film 2 has the following spectral characteristics SP.

[0038] The reflective filter film 2 can allow light of a first wavelength range W1 to at least partially penetrate. The first wavelength range is between 370 nm and 450 nm, and optionally between 370 nm and 425 nm.

[0039] The reflective filter film 2 can at least partially block light of a second wavelength range W2 from penetrating and reflect the light of the second wavelength range W2. The second wavelength range W2 is between 450 nm and 900 nm, and optionally between 450 nm and 850 nm.

[0040] From another perspective, please refer to Figure 5 The reflective filter film 2 has a first light transmittance for light of the first wavelength range W1, and the reflective filter film 2 has a second light transmittance for light of the second wavelength range W2. The first light transmittance (or the average of the first light transmittance) is greater than the second light transmittance (or the average of the second light transmittance).

[0041] The first light transmittance of the reflective filter film 2 for light of the first wavelength range W1 is not less than 50%, optionally not less than 60%, and particularly preferably between 60% and 99.9%.

[0042] The second light transmittance of the reflective filter film 2 for light of the second wavelength range W2 is not greater than 25%, optionally not greater than 20%, and particularly preferably between 1% and 20%. In addition, the light reflectance of the reflective filter film 2 for light of the second wavelength range W2 is not less than 75%, optionally not less than 80%, and particularly preferably not less than 99%. That is, at least 75% of the light of the second wavelength range W2 is reflected by the reflective filter film 2.

[0043] In the present embodiment, the reflective filter film 2 is formed by stacking multiple layers of inorganic film layers or polymer film layers with different refractive indexes, thereby having wavelength selectivity for light transmittance and high reflectivity for light of specific wavelengths. The reflective filter film 2 has good chemical and physical stability, and is resistant to environmental factors such as temperature changes and humidity, and is suitable for long-term use.

[0044] In the present embodiment, the reflective filter film 2 is formed by stacking multiple layers of polymer film layers with different refractive indexes, with a total film thickness of about 25-50 microns. From the spectrum of the reflective filter film 2, it can be observed that there is a significant change in light transmittance at about 450 nm, so that light with a wavelength less than 450 nm and optionally less than 425 nm (first wavelength range W1) can penetrate the reflective filter film 2, while light with a wavelength of 450-850 nm (second wavelength range W2) cannot penetrate the reflective filter film 2 and is mostly reflected by the reflective filter film 2. However, the reflective filter film 2 of the present application is not limited in the above manner. Figure 5

[0045] Thus, the first light L1 (with a first light wavelength of 370-450 nm) emitted by each light-emitting diode 11 can mostly penetrate the reflective filter film 2, thereby having a higher light utilization efficiency.

[0046] It is worth mentioning that the light transmittance of the above-mentioned reflective filter film 2 can be tested, for example, by the standard test method of ASTM D1003, and the light reflectance of the reflective filter film 2 can be tested, for example, by the standard test method of ASTM E903, but the present application is not limited thereto.

[0047] Further, the wavelength conversion film 3 is disposed on the side surface of the reflective filter film 2 away from the backlight module 1, and the wavelength conversion film 3 is used to convert the light penetrating the reflective filter film 2 in terms of light wavelength.

[0048] In the present embodiment, the wavelength conversion film 3 has the following optical properties. That is, the wavelength conversion film 3 can convert the first light L1 penetrating the reflective filter film 2 in terms of light wavelength to form a second light L2. The second light L2 has a second light wavelength of 450-900 nm (optionally 450-850 nm). That is, the second light L2 is visible light in the R, G, B range (i.e., red light, green light, or blue light).

[0049] Further, the wavelength conversion film 3 is a quantum dot film. The quantum dot film is made of nanoscale quantum dots (semiconductor materials) that can absorb light of specific wavelengths and re-emit light of different wavelengths. ​

[0050] When the first light L1 penetrates the reflective filter film 2 and irradiates the wavelength conversion film 3 (quantum dot film), the quantum dots in the wavelength conversion film 3 will absorb the first light L1 and emit the second light L2 with a wavelength of 450-900 nm (optionally 450-850 nm), so that the wavelength conversion film 3 can effectively convert the incident light into visible light in the R, G, and B ranges, thereby achieving efficient wavelength conversion.

[0051] The above-mentioned characteristics of the wavelength conversion film 3 (quantum dot film) can significantly improve the color saturation and brightness of the display, and provide more vivid and accurate color performance.

[0052] Further, the optical film 4 is arranged on the side of the wavelength conversion film 3 away from the reflective filter film 2. In this embodiment, the optical film 4 is arranged separately from the wavelength conversion film 3, but the present application is not limited thereto, and the optical film 4 can also be attached to the wavelength conversion film 3.

[0053] The optical film 4 is used to provide a path for the second light L2 formed by wavelength conversion of the wavelength conversion film 3 to pass through, so as to be directed towards the polarizing film 5 (such as a polarizing plate) of the liquid crystal display panel.

[0054] The optical film 4 can be, for example, at least one of a light diffusion film, a light condensing film, and a prism film.

[0055] In this embodiment, the optical film 4 is a light diffusion film. For example, the light diffusion film is used to uniformly scatter the incident light (second light L2), reduce the phenomenon of uneven brightness, and thus provide a more uniform light source. The light diffusion film is made of a material with tiny particles or surface microstructures, which can cause multiple scattering of light when passing through the film, thereby achieving light diffusion effect.

[0056] Further, the light condensing film concentrates the scattered light, thereby improving the utilization rate and brightness of light. The light condensing film, through special optical design, converges light from different directions to a more concentrated area, thereby enhancing the brightness and contrast of the display.

[0057] In addition, the prism film changes the path of light through the internal micro-prism structure, for controlling the directionality of light and improving the brightness and contrast of the display. The prism film can refract and reflect light according to the designed path, thereby guiding the light to the desired position.

[0058] The above-mentioned assembly configuration of the optical film 4 can be changed according to the design requirements of the product, and the present application is not limited thereto.

[0059] Furthermore, the polarizing film 5 is disposed on the side of the optical film 4 that is away from the wavelength conversion film 3. In this embodiment, the polarizing film 5 is disposed at a distance from the optical film 4, but this application is not limited thereto.

[0060] The polarizing film 5 can be, for example, the lower polarizing film of a liquid crystal display panel, which is used to allow a portion of the second light L2 formed by the wavelength conversion of the wavelength conversion film 3 to pass through and a portion to be reflected.

[0061] More specifically, the polarizing film 5 is a reflective polarizing film, and the second ray L2 includes P-polarized light L2P and N-polarized light L2N. The polarizing film 5 allows the P-polarized light L2P in the second ray L2 to pass through, and reflects the N-polarized light L2N in the second ray L2.

[0062] Based on the above configuration, please refer to Figure 4 As shown, when the liquid crystal display E is running, a plurality of light-emitting diodes 11 (e.g., mini LEDs) in the backlight module 1 emit a first light L1 with a first light wavelength between 370 nanometers and 450 nanometers.

[0063] The reflective filter 2 allows the first light ray L1 to pass through while blocking other light rays outside the aforementioned wavelength range (370 nm to 450 nm). Next, the wavelength conversion film 3 converts the wavelength of the first light ray L1 that has passed through the reflective filter 2, thereby forming a second light ray L2 with a wavelength between 450 nm and 900 nm. Then, the optical film 4 (such as a light-diffusing film, a light-concentrating film, or a prism sheet) allows the second light ray L2 to pass through.

[0064] Finally, the polarizing film 5 allows the P-polarized light L2P in the second ray L2 to penetrate and travel toward the liquid crystal layer, and reflects the N-polarized light L2N in the second ray L2.

[0065] The N-polarized light L2N of the second ray L2, after being reflected by the polarizing film 5, will pass through the optical film 4 and the wavelength conversion film 3 in sequence along a reflection path, and then illuminate the reflective filter film 2 again. The reflective filter film 2 will reflect the N-polarized light L2N again, causing the N-polarized light L2N to pass through the wavelength conversion film 3 and the optical film 4 in sequence along another reflection path, and then be reflected back to the polarizing film 5, so that the N-polarized light L2N in the second ray L2 has a better chance of passing through the polarizing film 5.

[0066] It is worth mentioning that, due to the optical characteristics of the reflective filter film 2, which blocks the penetration of light in the second wavelength range W2 (450-900 nm, optionally 450-850 nm) and reflects the light in the second wavelength range W2, the second light L2 (N-polarized light L2N) with a wavelength of 450-900 nm (optionally 450-850 nm) cannot penetrate the reflective filter film 2 after being reflected and encountering the reflective filter film 2, but is reflected by the reflective filter film 2.

[0067] In addition, since the reflective filter film 2 is fully covered on the plurality of light-emitting diodes 11 of the backlight module 1, all the reflected N-polarized light L2N is reflected by the reflective filter film 2, thereby avoiding the situation in the prior art that the reflected light does not encounter the reflective film and disappears in the backlight module 1.

[0068] [Advantages of the embodiments]

[0069] According to the above configuration, the liquid crystal display provided by the embodiments of the present application can greatly improve the light source utilization efficiency, effectively avoid the light loss, and improve the image display brightness under the condition of low power consumption, by means of the technical scheme of "a reflective filter film is arranged on one side of the backlight module to receive the first light; the reflective filter film has the following spectral characteristics: the reflective filter film can allow at least part of the light in a first wavelength range to penetrate; the first wavelength range is 370-450 nm; the reflective filter film can at least partially block the penetration of light in a second wavelength range, and reflect the light in the second wavelength range; the second wavelength range is 450-900 nm", and "a wavelength conversion film is arranged on the side of the reflective filter film away from the backlight module, and the wavelength conversion film can perform wavelength conversion on the first light to form a second light".

[0070] The above embodiments and / or implementations are only used to illustrate the preferred embodiments and / or implementations of the present application, and do not limit the embodiments of the present application in any form. Any person skilled in the art can make some changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the present application, but should be considered as the same technology or embodiment as the present application.

Claims

1. A liquid crystal display, characterized by comprising: The liquid crystal display comprises: a backlight module comprising a plurality of light emitting diodes arranged in a spaced-apart manner, and each of the light emitting diodes is capable of emitting a first light; a reflective filter film disposed on a side of the backlight module to receive the first light, wherein the reflective filter film has the following spectral characteristics: the reflective filter film is capable of allowing at least partial transmission of light in a first wavelength range, wherein the first wavelength range is between 370 nm and 450 nm; the reflective filter film is capable of at least partially blocking transmission of light in a second wavelength range and reflecting the light in the second wavelength range, wherein the second wavelength range is between 450 nm and 900 nm; and a wavelength conversion film disposed on a side of the reflective filter film away from the backlight module, and the wavelength conversion film is capable of performing wavelength conversion on the first light to form a second light.

2. The liquid crystal display of claim 1, wherein, The reflective filter film has a first light transmittance for the light in the first wavelength range, and a second light transmittance for the light in the second wavelength range, and the first light transmittance is greater than the second light transmittance.

3. The liquid crystal display of claim 1, wherein, In the spectral characteristics of the reflective filter film, the first wavelength range is between 370 nm and 425 nm, and the second wavelength range is between 450 nm and 850 nm.

4. The liquid crystal display of claim 3, wherein, The first light transmittance is not less than 50%, and the second light transmittance is not greater than 25%.

5. The liquid crystal display of claim 1, wherein, Each of the light emitting diodes is a sub-millimeter light emitting diode, and the first light emitted by each of the light emitting diodes has a first light wavelength between 370 nm and 450 nm, and the second light formed by the wavelength conversion film has a second light wavelength between 450 nm and 900 nm.

6. The liquid crystal display of claim 1, wherein, The reflective filter film completely covers the light emitting diodes of the backlight module.

7. The liquid crystal display of claim 1, wherein, The liquid crystal display further comprises: an optical film disposed on a side of the wavelength conversion film away from the reflective filter film to provide transmission of the second light, wherein the optical film is at least one of a light diffusion film, a light condensing film, and a prism film; and a polarizing film disposed on a side of the optical film away from the wavelength conversion film, wherein the polarizing film is a reflective polarizing film, and the polarizing film allows transmission of a P-polarized light in the second light and reflects an N-polarized light in the second light.

8. The liquid crystal display of claim 7, wherein, After the polarizing film reflects the N-polarized light in the second light, the N-polarized light can sequentially transmit the optical film and the wavelength conversion film along a reflection path to irradiate the reflective filter film, and then the reflective filter film reflects the N-polarized light again to irradiate the polarizing film again along another reflection path.

9. The liquid crystal display of claim 1, wherein, The reflective filter film is formed by stacking a plurality of inorganic film layers or polymer film layers with different refractive indexes.

10. The liquid crystal display of claim 1, wherein, The wavelength conversion film is a quantum dot film.

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