Backlight module, display panel and display device

Abstract

The embodiment of the invention relates to a backlight module, a display panel and a display device, the backlight module comprises at least one layer of transmission medium, a back plate and a light-emitting module, the light-emitting module is arranged on the back plate, and the at least one layer of transmission medium is spaced by a preset distance through a support; light emitted by the light-emitting module enters the at least one layer of transmission medium at a Brewster angle, passes through the at least one layer of transmission medium and then is emitted as linearly polarized light in a target polarization direction. According to the embodiment of the invention, the Brewster angle in the optical technology is effectively utilized, and all or most of the light transmitted through the at least one layer of transmission medium is linearly polarized light, so that the effective control on the polarization state of the light incident to the liquid crystal panel is realized, the emitted linearly polarized light can be completely incident into the liquid crystal panel, and the quality of the liquid crystal panel is improved. And the energy utilization rate of the backlight module is improved.

Description

Technical Field

[0001] The present application relates to the technical field of display panels, and in particular to a backlight module, a display panel and a display device. Background Art

[0002] The backlight source of current display panels usually uses ordinary circularly polarized light, which is close to the form of natural light, and is combined with a liquid crystal panel to form a liquid crystal module. Usually, a polarizer that can pass linearly polarized light needs to be attached to the surface of the liquid crystal panel. Then, when the non-linearly polarized light entering the polarizer from the outside passes through the lower surface of the liquid crystal panel, only the light with a polarization direction parallel to the polarizer on the liquid crystal panel can enter the liquid crystal panel. In this way, most of the backlight cannot effectively pass through the liquid crystal panel, resulting in low energy utilization of the backlight source. Summary of the invention

[0003] In view of this, in order to solve some or all of the above technical problems, the embodiments of the present application provide a backlight module, a display panel and a display device.

[0004] In a first aspect, an embodiment of the present application provides a backlight module, which includes: at least one layer of transmissive medium, a back panel, and a light-emitting module, wherein the light-emitting module is arranged on the back panel; light emitted by the light-emitting module is incident on at least one layer of transmissive medium at a Brewster angle, and after passing through at least one layer of transmissive medium, is emitted as linearly polarized light in a target polarization direction.

[0005] In a possible implementation manner, the number of layers of the at least one layer of the transmissive medium is greater than or equal to two, and two adjacent layers of the transmissive medium are spaced a preset distance apart by a support.

[0006] In one possible embodiment, the light-emitting unit includes a light-emitting diode and a transparent colloid, and the transparent colloid is wrapped around the light-emitting diode; on each cross-section containing the main optical axis of the light-emitting diode, for the light emitted by the light-emitting diode within a preset angle range, if the angle between the light and the main optical axis is the Brewster angle, then at the intersection of the light and the light-emitting surface of the transparent colloid, the tangent plane of the surface of the transparent colloid is perpendicular to the light; if the angle between the light and the main optical axis is not the Brewster angle, then at the intersection of the light and the light-emitting surface of the transparent colloid, the tangent plane at the intersection is used as the medium interface, and the light is refracted on the medium interface and is incident on at least one layer of transmission medium at the Brewster angle.

[0007] In one possible embodiment, the light-emitting unit includes a light-emitting diode and a lens, wherein the lens is wrapped around the light-emitting diode; the lens includes a central reflection surface and an outer transmission surface, wherein the light emitted by the light-emitting diode to the central reflection surface is reflected to the outer transmission surface; for the light reflected to the outer transmission surface, at the intersection of the light and the outer transmission surface, the tangent plane at the intersection is taken as the medium interface, and the light is refracted on the medium interface, and is incident on at least one layer of transmission medium at a Brewster angle.

[0008] In a possible embodiment, the outer transmission surface includes a first transmission surface and a second transmission surface, and the angle between the tangent plane of each point on the first transmission surface and the main optical axis of the light-emitting diode is within a first preset angle range, so that the light emitted by the light-emitting diode to the first transmission surface is totally reflected on the first transmission surface, and then reflected on the central reflection surface, and reflected by the central reflection surface to the first transmission surface; for the light reflected on the first transmission surface, at the intersection of the light and the first transmission surface, the tangent plane where the intersection is located is the medium interface, the light is refracted on the medium interface, and is incident on at least one layer of transmission medium at a Brewster angle; for the light emitted by the light-emitting diode to the second transmission surface, at the intersection of the light and the second transmission surface, the tangent plane where the intersection is located is the medium interface, the light is refracted on the medium interface, and is incident on at least one layer of transmission medium at a Brewster angle.

[0009] In one possible implementation, the angle between the tangent plane at each point on the central reflection surface and the main optical axis of the light-emitting diode is within a second preset angle range, so that the light emitted by the light-emitting diode to the central reflection surface is totally reflected on the central reflection surface, then reflected to the outer transmission surface, refracted by the outer transmission surface, and incident on at least one layer of transmission medium at the Brewster angle.

[0010] In a possible implementation, a reflective coating is provided on the central reflective surface, and the reflective coating is used to reflect the light emitted to the central reflective surface to the outer transmission surface, refract through the outer transmission surface, and enter at least one layer of transmission medium at Brewster's angle.

[0011] In a possible implementation manner, the number of layers of the at least one layer of transmissive medium is three, the support is a transparent adhesive strip, and each transmissive medium is spaced a preset distance apart by the transparent adhesive strip.

[0012] In a possible implementation manner, a reflective coating is disposed on the back plate for reflecting light reflected by the at least one layer of the transmissive medium back to the at least one layer of the transmissive medium.

[0013] In a second aspect, an embodiment of the present application provides a display panel, which includes: a liquid crystal panel and a backlight module described in the first aspect above, and the backlight module emits linearly polarized light in a target polarization direction to the liquid crystal panel.

[0014] In a third aspect, an embodiment of the present application provides a display device, comprising: the display panel described in the second aspect above.

[0015] The backlight module, display panel and display device provided by the embodiment of the present application are provided with at least one layer of transmission medium, a back plate and a light-emitting module, wherein at least one layer of transmission medium is spaced by a support at a preset distance, and the light-emitting module is provided on the back plate, and the light emitted by the light-emitting module is incident on at least one layer of transmission medium at a Brewster angle, and after passing through at least one layer of transmission medium, is emitted as linearly polarized light in a target polarization direction. The embodiment of the present application effectively utilizes the Brewster angle in optical technology, so that all or most of the light transmitted through at least one layer of transmission medium is linearly polarized light, thereby achieving effective control of the polarization state of the light incident on the liquid crystal panel, and the emitted linearly polarized light can be completely injected into the liquid crystal panel, thereby improving the energy utilization rate of the backlight module. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0019] Figure 1 A schematic diagram of the structure of a backlight module provided in an embodiment of the present application;

[0020] Figure 2A is a schematic diagram of the polarization state of circularly polarized light;

[0021] Figure 2B is a schematic diagram of the polarization state of linearly polarized light;

[0022] Figure 3 A schematic diagram of a backlight module provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of the structure of a light-emitting unit provided in an embodiment of the present application;

[0024] Figure 5 A schematic diagram of light distribution on a cross section including a main optical axis of a light-emitting unit provided in an embodiment of the present application;

[0025] Figure 6 A schematic diagram of the structure of another light-emitting unit provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of light distribution on another cross section including the main optical axis of a light-emitting unit provided in an embodiment of the present application;

[0027] Figure 8 A schematic diagram of the structure of a display panel provided in an embodiment of the present application;

[0028] Fig. 9 A schematic diagram of the structure of a display device provided in an embodiment of the present application.

[0029] Reference numerals:

[0030] 100-backlight module; 101-at least one layer of transmission medium; 102-back plate; 103-light-emitting module; 1031-transparent colloid; 1032-light-emitting diode; 1033-lens; 10331-central reflection surface; 10332-outer transmission surface; 103321-first transmission surface; 103322-second transmission surface; 800-display panel; 801-liquid crystal panel; 8011-polarizer; 901-panel frame; 902-power module; 903-data receiving module. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the numerical expressions and the numerical values ​​described in these embodiments do not limit the scope of the present application.

[0032] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of the present application are only used to distinguish between different steps, devices, modules and other objects, and do not represent any specific technical meanings, nor do they indicate the logical order between them.

[0033] It should also be understood that in this embodiment, “plurality” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0034] It should also be understood that any component, data or structure mentioned in the embodiments of the present application can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0035] In addition, the term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0036] It should also be understood that the description of the various embodiments in this application focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced to each other, and for the sake of brevity, they will not be described one by one.

[0037] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0038] Technologies, structures, and devices known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the above-mentioned technologies, structures, and devices should be considered as part of the specification.

[0039] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0040] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. To facilitate the understanding of the embodiments of the present application, the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0041] Figure 1 The schematic diagram of the structure of a backlight module 100 provided in an embodiment of the present application is generally used in a display panel to provide backlight illumination for a liquid crystal panel in the display panel. The backlight module 100 specifically includes: at least one layer of a transmission medium 101 ( Figure 1 It shows three layers of transmissive medium), a back plate 102 , and a light emitting module 103 , wherein the light emitting module 103 is disposed on the back plate 102 .

[0042] The material of the at least one layer of transmissive medium 101 may be a material with high refractive index and high light transmittance, such as PET, PC, glass, etc. These materials have good optical uniformity and high light transmittance, which helps to increase the light intensity incident on the liquid crystal panel.

[0043] In this embodiment, the light emitted by the light emitting module 103 is incident on at least one layer of the transmissive medium 101 at the Brewster angle, and after passing through at least one layer of the transmissive medium, is emitted as linearly polarized light in a target polarization direction.

[0044] Figure 2A is a schematic diagram of the polarization state of circularly polarized light (natural light), Figure 2A It can be seen that the vibration trajectory of circularly polarized light is circular. Figure 2B is a schematic diagram of the polarization state of linearly polarized light, Figure 2B As can be seen, the vibration trajectory of linear polarized light is a straight line. Since the currently commonly used backlight module 100 emits circularly polarized light, and the polarizer on the liquid crystal panel can only transmit light parallel to its polarization direction, if the light incident on the liquid crystal panel is circularly polarized light, part of the light will not be able to pass through, resulting in insufficient light intensity received and transmitted by the liquid crystal panel.

[0045] Here we first introduce the concept of Brewster's angle: when the incident light is emitted from medium A to medium B, where the refractive index of A is n1 and the refractive index of medium B is n2, if the incident angle α satisfies tanα=n1 / n2, then this angle is defined as the Brewster's angle. The light incident at the Brewster's angle is reflected on the surface of medium B, and the polarization direction of the reflected light is perpendicular to the incident plane (the plane where the incident light and the normal are located). After entering medium B, it is refracted, and the polarization direction of most of the refracted light is parallel to the incident plane, and the polarization direction of a small part is perpendicular to the incident plane.

[0046] Optionally, the number of layers of the at least one layer of the transmission medium 101 may be greater than or equal to two, and a preset distance may be provided between two adjacent layers of the transmission medium through a support. According to the transmission characteristics of linearly polarized light, the more layers of the transmission medium there are, the higher the content of linearly polarized light in a single polarization direction transmitted. Therefore, by providing at least two layers of the transmission medium, the light passing through the at least two layers of the transmission medium may be approximately linearly polarized light, thereby making the light incident on the liquid crystal panel approximately linearly deflected light, thereby increasing the light intensity transmitted from the liquid crystal panel.

[0047] Optionally, the number of layers of the at least one layer of transmission medium 101 is three (i.e. Figure 1 The three-layer transmission medium shown in the figure is supported by a transparent adhesive strip, and each transmission medium is separated by a preset distance by the transparent adhesive strip. According to the transmission characteristics of linearly polarized light, the more layers of transmission medium there are, the higher the content of linearly polarized light in a single polarization direction transmitted. However, too many layers of transmission medium will increase the structural complexity of the backlight module 100 and cause a decrease in the amount of light transmitted. Therefore, selecting three layers of transmission medium can take into account both the quality of linearly polarized light and the structural complexity of the actual product.

[0048] like Figure 3As shown, it shows a schematic diagram of the backlight module 100 provided in the present application generating linear polarized light. The incident angle of the light emitted by the light emitting module 103 in this embodiment to at least one layer of the transmission medium 101 is the Brewster angle β. The dots on the light in the figure indicate that the polarization direction is perpendicular to the incident plane, and the line segments on the light indicate that the polarization direction is parallel to the incident plane. After the incident light passes through at least one layer of the transmission medium 101, the polarization direction of most of the light that finally enters the liquid crystal panel is parallel to the incident plane. Therefore, it can be considered that the light entering the liquid crystal panel is linearly polarized light.

[0049] Since a polarizer is usually disposed on the surface of the liquid crystal panel, a polarizer parallel to the polarization direction of the incident linearly polarized light may be disposed so that the linearly polarized light completely passes through the liquid crystal panel, thereby improving the brightness of the liquid crystal panel.

[0050] The light emitting module 103 in this embodiment may include a light emitting diode and a light guide device, and the light guide device may change the emission angle of the light emitted by the light emitting diode. For example, a lens with a special structure may be provided on the light emitting diode, a transparent colloid with a special structure may be covered, or a reflector may be provided, so that the light emitted by the light emitting module 103 enters at least one layer of the transmission medium 101 at a Brewster angle.

[0051] The backlight module provided in the embodiment of the present application is provided with at least one layer of transmission medium, a back plate, and a light-emitting module, wherein at least one layer of transmission medium is spaced by a support at a preset distance, and the light-emitting module is provided on the back plate, and the light emitted by the light-emitting module is incident on at least one layer of transmission medium at a Brewster angle, and after passing through at least one layer of transmission medium, is emitted as linearly polarized light in a target polarization direction. The embodiment of the present application effectively utilizes the Brewster angle in optical technology, so that all or most of the light transmitted through at least one layer of transmission medium is linearly polarized light, thereby achieving effective control of the polarization state of the light incident on the liquid crystal panel, and the emitted linearly polarized light can be completely injected into the liquid crystal panel, thereby improving the energy utilization rate of the backlight module.

[0052] In some optional implementations of this embodiment, the light emitting module 103 includes at least two light emitting units, and the at least two light emitting units are arranged in an array on the back panel 102, so that the light emitted by the backlight module 100 to the liquid crystal panel is more evenly distributed.

[0053] In some optional implementations of this embodiment, such as Figure 4 As shown, each light-emitting unit in the light-emitting module 103 includes a light-emitting diode 1032 and a transparent colloid 1031 , and the transparent colloid 1031 is wrapped around the light-emitting diode.

[0054] In the light-emitting unit, the main optical axis of the light-emitting diode 1032 (eg Figure 5The straight line a shown is the principal optical axis) as the axis, and countless cross sections can be determined within a range of 360°. On each cross section containing the principal optical axis of the light emitting diode 1032, for the light emitted by the light emitting diode 1032 within a preset angle range, if the angle between the light and the principal optical axis is the Brewster angle, then at the intersection of the light and the light emitting surface of the transparent colloid 1031, the section of the surface of the transparent colloid 1031 is perpendicular to the light.

[0055] If the angle between the light ray and the principal optical axis is not the Brewster angle, then at the intersection of the light ray and the light-emitting surface of the transparent colloid 1031, the tangent plane at the intersection is taken as the medium interface, and the light ray is refracted on the medium interface and incident on at least one layer of the transmissive medium 101 at the Brewster angle.

[0056] Specifically, usually, the light emitting diode 1032 is a Lambertian light source, and its effective luminous angle is defined as the angle corresponding to half the maximum light intensity, which is usually 120°. Therefore, based on the light emitting surface of the light emitting diode 1032, the above angle range is 30°-150°. Within this range, the light is emitted from the transparent colloid 1031 into the air, that is, from the optically dense medium to the optically sparse medium, and refracted in the air. Figure 5 As shown, at each point on the light-emitting surface of the transparent colloid 1031, if it is known that the incident light enters at least one layer of transparent medium at the Brewster angle, the angle at which each incident light is deflected on the light-emitting surface can be determined, and according to the law of refraction (sinθ1 / sinθ2=n2 / n1, where θ1 is the incident angle, θ2 is the refraction angle, n2 is the medium into which the light enters, and n1 is the medium from which the light exits), the tangent plane of each point on the light-emitting surface can be determined, and the shape of the light-emitting surface of the entire transparent colloid 1031 can be determined according to the tangent plane of each point. According to the shape, the light-emitting unit can be manufactured.

[0057] Figure 5 The figure shows the light distribution on a cross section of the main optical axis of the light-emitting unit. Figure 5 It can be seen that the light-emitting unit emits a parallel light beam, and the parallel light beam is incident on at least one layer of light-transmitting medium at a Brewster angle.

[0058] like Figure 5 As shown, the main optical axis a is the normal direction of the light emitting surface of the light emitting diode 1032. The light emitting surface of the transparent colloid 1031 is used as the medium interface. At the intersection of the incident light i and the light emitting surface of the transparent colloid 1031, the tangent plane of the point is set to be perpendicular to the incident light i. After the incident light i is emitted from the light emitting surface, no refraction occurs, and it is incident on at least one layer of the transmission medium 101 along the original direction at the Brewster angle β.

[0059] like Figure 5As shown, for a light whose angle with the principal optical axis is not the Brewster angle, if the broken line light emitted on the medium interface is to be incident on at least one layer of the transmissive medium 101 at the Brewster angle β, the angle between the light and the refracted light can be determined. In the stage of designing the transparent colloid 1031, the angle can be used as one of the limiting conditions, and other conditions such as the size limit of the transparent colloid 1031, the light emitting angle range, and the light emitting surface size of the light emitting diode 1032 can be set, and the angle between the tangent plane at the above intersection of the transparent colloid 1031 and the light is adjusted. According to the law of refraction, the refracted light is allowed to satisfy the condition of being incident on at least one layer of the transmissive medium 101 at the Brewster angle β, thereby determining the shape and size of the transparent colloid 1031.

[0060] The incident angle θ of the light relative to the interface of the medium into which it enters satisfies the following relationship:

[0061] θ=90°-α-arctan(d / h) (1)

[0062] Among them, α is the angle between the light and the light-emitting surface of the LED 1032, h is the height of the intersection of the light and the light-emitting surface of the transparent colloid 1031 relative to the light-emitting surface of the LED 1032, and d is the distance between the normal c of the light and the projection point of the intersection on the light-emitting surface.

[0063] like Figure 5 As shown, for any light ray b, the light ray intersects with the light-emitting surface at point A, and the perpendicular line of the tangent plane through point A is the normal line c. The angle between c and b is the incident angle θ. According to the characteristics of the right triangle, the incident angle of the light ray can be determined according to formula (1). By calculating the incident angles corresponding to multiple light rays, the tangent plane of each light ray at the intersection of the light-emitting surface 10321 can be determined. By combining these tangent planes, the shape of the light-emitting surface can be determined.

[0064] In this embodiment, a transparent colloid is wrapped around the light-emitting diode and the shape of the transparent colloid is pre-designed so that the light-emitting unit can emit parallel light by refraction and inject it into at least one layer of light-transmitting medium at the Brewster angle. The light-emitting unit of this solution has a compact structure and a simple manufacturing method. The installation stability and convenience of the light-emitting unit are higher, which helps to improve the overall stability and manufacturing efficiency of the backlight module.

[0065] In some optional implementations of this embodiment, such as Figure 6, which shows a cross-sectional schematic diagram of the main optical axis of the light-emitting unit. The light-emitting unit includes a light-emitting diode 1031 and a lens 1033, wherein the lens 1033 is wrapped around the light-emitting diode 1032; the lens 1033 includes a central reflection surface 10331 and an outer transmission surface 10332. The light emitted by the light-emitting diode 1032 to the central reflection surface 10331 is reflected to the outer transmission surface 10332.

[0066] Specifically, the central reflection surface 10331 can be a plane or a curved surface. The manufacturing method of a plane is simpler, which helps to improve the manufacturing efficiency. The curved surface can more accurately control the reflection angle of the reflected light, so that the light emission angle is more consistent with the desired angle.

[0067] For the light reflected on the outer transmission surface 10332, at the intersection of the light and the outer transmission surface 10332, the tangent plane at the intersection is taken as the medium interface, and the light is refracted on the medium interface and incident on at least one layer of transmission medium 101 at the Brewster angle.

[0068] Once the emission direction of the reflected light on the central reflection surface 10331 and the desired emission direction that meets the Brewster angle requirement are known, the inclination angle of the tangent plane at each point on the outer transmission surface 10332 can be set according to the law of refraction, so that the light incident on the outer transmission surface 10332 is refracted and then incident on at least one layer of the transmission medium 101 at the Brewster angle.

[0069] In this embodiment, the shape of the lens is designed so that the light emitted by the light emitting diode is reflected and refracted to finally obtain light that meets the Brewster angle requirement, so that the luminous energy is more concentrated on one side of the central reflection surface, and the light intensity irradiated to the liquid crystal panel is higher, which helps to further improve the backlight brightness of the liquid crystal panel.

[0070] In some optional implementations of this embodiment, such as Figure 7As shown, it shows a schematic diagram of light distribution of the light-emitting unit. The outer transmission surface 10332 includes a first transmission surface 103321 and a second transmission surface 103322. The angle between the tangent plane of each point on the first transmission surface 103321 and the main optical axis a of the light-emitting diode 1032 is within a first preset angle range, so that the light emitted by the light-emitting diode 1032 to the first transmission surface 103321 is totally reflected on the first transmission surface 103321, and then reflected to the central reflection surface 10331, and reflected from the central reflection surface 10331 to the first transmission surface 103321, refracted through the first transmission surface 103321, and incident on at least one layer of the transmission medium 101 at the Brewster angle. For the light reflected on the first transmission surface 103321, at the intersection of the light and the first transmission surface 103321, the tangent plane at the intersection is the medium interface, the light is refracted on the medium interface, and incident on at least one layer of the transmission medium 101 at the Brewster angle.

[0071] For the light emitted by the light emitting diode 1032 onto the second transmission surface 103322, at the intersection of the light and the second transmission surface 103322, the tangent plane at the intersection is taken as the medium interface, and the light is refracted on the medium interface and incident on at least one layer of the transmission medium 101 at the Brewster angle.

[0072] Specifically, the first preset angle range is used to limit the inclination angle of the tangent plane at each point on the first transmission surface 103321, and further limit the incident angle of each light irradiated onto the first transmission surface 103321, so that the incident angle is greater than the critical angle of total reflection.

[0073] like Figure 7 As shown, the light e irradiates the first transmission surface 103321 at a position close to the intersection of the second transmission surface 103322, and total reflection occurs at this position. The critical angle calculation formula of total reflection is shown in the following formula (2):

[0074] sinθ1 / sinθ2=1 / n (2)

[0075] Among them, θ1 is the incident angle of the light in the lens 1033 entering the interface between the lens 1033 and the air, that is, the angle between the incident light and the normal of the interface, θ2 is the refraction angle, n is the refractive index of the lens 1033 material, and 1 is the refractive index of air.

[0076] The light f reflected by the central reflection surface 10331 is refracted again on the first transmission surface 103321 and emitted at the Brewster angle. When designing the shape of the first transmission surface 103321, the total reflection and the limitation of the emitted light to be emitted at the Brewster angle can be used as constraints to determine the shape of the first transmission surface 103321. When designing the shape of the second transmission surface 103322, it is only necessary to set the inclination angle of the tangent plane at each point on the second transmission surface 103322 so that the light emitted by the light emitting diode 1032 is refracted on the second transmission surface 103322 and incident on at least one layer of the transmission medium 101 at the Brewster angle.

[0077] In this embodiment, by setting the first transmission surface and the second transmission surface, most of the light emitted by the light emitting diode can be incident on at least one layer of transmission medium according to the Brewster angle under the action of total reflection and refraction, thereby helping to increase the energy density of the emitted light and further increase the brightness of the light irradiating the liquid crystal panel.

[0078] In some optional implementations of the present embodiment, the angle between the tangent plane of each point on the central reflection surface 10331 and the main optical axis of the light-emitting diode 1032 is within a second preset angle range, so that the light emitted by the light-emitting diode 1032 to the central reflection surface 10331 is totally reflected on the central reflection surface 10331, then reflected to the outer transmission surface 10332, refracted by the outer transmission surface, and incident on at least one layer of the transmission medium 101 at the Brewster angle.

[0079] The second preset angle range is used to limit the inclination angle of the tangent plane at each point on the central reflection surface 10331, and further limit the incident angle of each light irradiated on the central reflection surface 10331, so that the incident angle is greater than the critical angle of total reflection. The critical angle can be calculated by the above formula (2) to limit the inclination angle of the tangent plane at each point on the central reflection surface 10331 relative to the main optical axis or the light-emitting surface of the light-emitting diode 1032, so that the light is totally reflected at any position incident on the central reflection surface 10331.

[0080] By setting the geometric features of the central reflection surface so that the light is totally reflected on the central reflection surface, the distribution of the light can be more effectively limited to avoid the transmission of the light on the central reflection surface, thereby helping to further improve the energy density of the light emitted by the light-emitting unit.

[0081] In some optional implementations of this embodiment, a reflective coating is provided on the central reflective surface 10331, and the reflective coating is used to reflect the light emitted onto the central reflective surface 10331 to the outer transmission surface 10332, refract through the outer transmission surface 10332, and impinge on at least one layer of transmission medium 101 at a Brewster angle.

[0082] Optionally, this embodiment may be combined with the above embodiment, that is, on the basis that the first reflection surface can undergo total reflection, a reflective coating is further added.

[0083] By providing a reflective coating on the central reflective surface, it is possible to further prevent light from being transmitted from the central reflective surface, so that the light-emitting unit can incident light at a Brewster angle onto at least one layer of transmission medium at a higher energy density.

[0084] In some optional implementations of this embodiment, a reflective coating is disposed on the back plate 102 for reflecting light reflected by at least one layer of the transmissive medium 101 back to the at least one layer of the transmissive medium 101 again.

[0085] After the light is reflected on the surface of at least one layer of the transmission medium, the reflected light is further reflected on the reflective coating on the back plate, thereby avoiding energy loss of the light on the back plate and increasing the light intensity of the light irradiated on the liquid crystal panel.

[0086] Figure 8 A schematic diagram of the structure of a display panel 800 provided in an embodiment of the present application is shown in FIG. Figure 8 As shown, the display panel specifically includes: a liquid crystal panel 801 and the backlight module 100 described in the above embodiments, and the backlight module 100 emits linear polarized light in a target polarization direction to the liquid crystal panel.

[0087] A polarizer 8011 may be provided on the liquid crystal panel 801, and the polarizer 8011 may be provided on two surfaces of the liquid crystal panel; after the linear polarized light emitted by the backlight module 100 is incident on the polarizer 8011, it passes through the polarizer and is incident on the liquid crystal panel, wherein the polarization direction of the polarizer 8011 is parallel to the target polarization direction of the linear polarized light of the backlight module 100.

[0088] According to the characteristics of the polarizer 8011, light parallel to the polarization direction of the polarizer can pass through the polarizer without causing energy loss.

[0089] The display panel provided in the embodiment of the present application, by applying the above-mentioned backlight module, can allow the linearly polarized light directed toward the liquid crystal panel to pass through the liquid crystal panel without loss, thereby greatly improving the energy utilization rate of the backlight module.

[0090] Fig. 9 A schematic diagram of the structure of a display device 900 provided in an embodiment of the present application is shown in FIG. Fig. 9 As shown, the display device includes the above Figure 8 The display panel 800 described in the illustrated embodiment. In addition, the display device 900 may further include a panel frame 901, a power module 902 and a data receiving module 903;

[0091] The display panel 800 is installed on the panel frame 901 .

[0092] The power supply end of the display panel 800 is connected to the power module 902 , and the signal receiving end of the display panel 800 is connected to the data receiving module 903 .

[0093] The power module 902 can provide the display panel 800 with the power required for operation, the data receiving module 903 can receive input data, and the display panel 800 drives the corresponding pixels to display the corresponding colors according to the received data.

[0094] In addition, the display device Fig. 9 In addition to the parts shown, it may also include a memory for storing data and programs, a processor for running application programs, a data transmission bus, various data interfaces (such as a network interface, a user interface), etc.

[0095] The display device provided in the embodiment of the present application can greatly improve the energy utilization rate of the backlight module and improve the display brightness by applying the above-mentioned display panel.

[0096] The professionals should further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different structures to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0097] It should be understood that the terms used in the text are only for the purpose of describing specific example embodiments, and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used in the text may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The steps, processes, and operations described in the text are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0098] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A backlight module, characterized in that: include: At least one layer of transmission medium, a back plate, and a light-emitting module, wherein the light-emitting module is arranged on the back plate; The light emitted by the light emitting module is incident on the at least one layer of transmission medium at a Brewster angle, and after passing through the at least one layer of transmission medium, is emitted as linearly polarized light in a target polarization direction.

2. The backlight module according to claim 1, characterized in that: The number of layers of the at least one layer of transmission medium is greater than or equal to two, and two adjacent layers of the transmission medium are spaced a preset distance apart by a support.

3. The backlight module according to claim 2, characterized in that: The light-emitting unit comprises a light-emitting diode and a transparent colloid, wherein the transparent colloid is wrapped around the light-emitting diode; On each cross section including the main optical axis of the light emitting diode, for a light ray emitted by the light emitting diode within a preset angle range, if the angle between the light ray and the main optical axis is the Brewster angle, then at the intersection of the light ray and the light emitting surface of the transparent colloid, the tangent plane of the surface of the transparent colloid is perpendicular to the light ray; If the angle between the light ray and the principal optical axis is not the Brewster angle, then at the intersection of the light ray and the light-emitting surface of the transparent colloid, the tangent plane at the intersection is taken as the medium interface, and the light ray is refracted on the medium interface and is incident on the at least one layer of transmissive medium at the Brewster angle.

4. The backlight module according to claim 2, characterized in that: The light-emitting unit comprises a light-emitting diode and a lens, wherein the lens is wrapped around the light-emitting diode; The lens comprises a central reflection surface and an outer transmission surface, wherein the light emitted by the light emitting diode onto the central reflection surface is reflected onto the outer transmission surface; For the light reflected on the outer transmission surface, at the intersection of the light and the outer transmission surface, the tangent plane at the intersection is taken as the medium interface, the light is refracted on the medium interface and is incident on the at least one layer of transmission medium at the Brewster angle.

5. The backlight module according to claim 4, characterized in that: The outer transmission surface comprises a first transmission surface and a second transmission surface, and the angle between the tangent plane at each point on the first transmission surface and the main optical axis of the light emitting diode is within a first preset angle range, so that the light emitted by the light emitting diode to the first transmission surface is totally reflected on the first transmission surface, then reflected to the central reflection surface, and then reflected from the central reflection surface to the first transmission surface; For the light reflected on the first transmission surface, at the intersection of the light and the first transmission surface, the tangent plane at the intersection is taken as the medium interface, the light is refracted on the medium interface, and is incident on the at least one layer of transmission medium at a Brewster angle; For the light emitted by the light emitting diode onto the second transmission surface, at the intersection of the light and the second transmission surface, the tangent plane at the intersection is taken as the medium interface, the light is refracted on the medium interface and is incident on the at least one layer of transmission medium at the Brewster angle.

6. The backlight module according to claim 4, characterized in that: The angle between the tangent plane of each point on the central reflection surface and the main optical axis of the light-emitting diode is within a second preset angle range, so that the light emitted by the light-emitting diode onto the central reflection surface is totally reflected on the central reflection surface, then reflected to the outer transmission surface, refracted by the outer transmission surface, and incident on the at least one layer of transmission medium at a Brewster angle.

7. The backlight module according to claim 4, characterized in that: A reflective coating is provided on the central reflective surface, and the reflective coating is used to reflect the light emitted to the central reflective surface to the outer transmission surface, refract through the outer transmission surface, and enter the at least one layer of transmission medium at Brewster's angle.

8. The backlight module according to claim 2, characterized in that: The at least one layer of transmissive medium has three layers, the support is a transparent adhesive strip, and each of the transmissive media is spaced apart by a preset distance through the transparent adhesive strip.

9. The backlight module according to any one of claims 1 to 8, characterized in that: The back plate is provided with a reflective coating for reflecting light reflected by the at least one layer of the transmissive medium back to the at least one layer of the transmissive medium.

10. A display panel, characterized in that: include: A liquid crystal panel and a backlight module as claimed in any one of claims 1 to 9, wherein the backlight module emits linearly polarized light in a target polarization direction to the liquid crystal panel.

11. A display device, characterized in that: include: The display panel as claimed in claim 10.

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