Backlight module and display device

Abstract

The invention discloses a backlight module and a display device, the display device comprises the backlight module and a liquid crystal display panel, the liquid crystal display panel is arranged on the light emitting side of the backlight module, and the backlight module comprises a back plate, a light bar, a polarization light guide plate and an optical film; the back plate comprises a bottom plate and side plates, and the side plates and the bottom plate are connected to define a containing cavity; the light bar is fixed with the side plate and comprises a plurality of polarized light-emitting devices which are arranged at intervals; the polarization light guide plate is arranged in the containing cavity, and the light inlet side of the polarization light guide plate is close to the light outlet side of the light bar. The optical film is arranged on the side, away from the bottom plate, of the polarization light guide plate and comprises a polarization-maintaining base material layer, and the polarization axis of the polarization-maintaining base material layer is parallel to the polarization axis of linearly polarized light emitted by the polarization light-emitting device. The light emitting efficiency of the display device can be improved.

Description

TECHNICAL FIELD

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

[0002] The display device includes a backlight module, a liquid crystal display panel and polarizing sheets located on the upper and lower sides of the liquid crystal display panel, and the liquid crystal display panel is arranged on the light emitting side of the backlight module. The backlight module of the display device of the conventional scheme emits non-polarized light, and when the non-polarized light passes through the polarizing sheet, a large amount of light is blocked by the polarizing sheet, resulting in low light efficiency of the display device. SUMMARY

[0003] Embodiments of the present application provide a backlight module and a display device to improve the light efficiency of the display device.

[0004] In a first aspect, embodiments of the present application provide a backlight module, comprising:

[0005] A back plate, the back plate comprising a bottom plate and a side plate, the side plate being connected with the bottom plate and surrounding a containing cavity;

[0006] A light bar, the light bar being fixed with the side plate, the light bar comprising a plurality of polarized light emitting devices, the plurality of polarized light emitting devices being arranged at intervals;

[0007] A polarized light guide plate, the polarized light guide plate being arranged in the containing cavity, and an incident light side of the polarized light guide plate being close to an outgoing light side of the light bar;

[0008] An optical film, the optical film being arranged on a side of the polarized light guide plate away from the bottom plate, the optical film comprising a polarization maintaining substrate layer, and a polarization axis of the polarization maintaining substrate layer being parallel to a polarization axis of linearly polarized light emitted by the polarized light emitting device.

[0009] Further, the backlight module further comprises a first anti-reflection layer, the first anti-reflection layer being arranged on a surface of the polarization maintaining substrate layer away from the bottom plate.

[0010] Further, the material of the first anti-reflection layer is at least one of magnesium fluoride, silicon dioxide, silicon dioxide-titanium oxide composite material or silicon dioxide-zirconium oxide composite material.

[0011] Further, the backlight module further comprises an anti-reflection layer, the anti-reflection layer being arranged on a surface of the first anti-reflection layer away from the bottom plate.

[0012] Further, the material of the anti-reflection layer is nano-porous aluminum oxide.

[0013] Further, the polarized light emitting device comprises:

[0014] A substrate;

[0015] an active layer, disposed on the substrate;

[0016] a photonic crystal layer, disposed on a surface of the active layer away from the substrate.

[0017] Further, the polarized light emitting device further comprises a second antireflection layer, disposed on a surface of the photonic crystal layer away from the substrate.

[0018] Further, the material of the polarization maintaining substrate layer comprises a cyclic olefin polymer or polymethyl methacrylate.

[0019] Further, the backlight module further comprises a polarized reflection layer, disposed on a surface of the polarized light guide plate close to the bottom plate.

[0020] In a second aspect, embodiments of the present application provide a display device, comprising a liquid crystal display panel, a first polarizer, a second polarizer, and the backlight module, the liquid crystal display panel is disposed on the light emitting side of the backlight module, the first polarizer is disposed on a surface of the liquid crystal display panel close to the backlight module, the second polarizer is disposed on a surface of the liquid crystal display panel away from the backlight module, the polarization axis of the first polarizer is parallel to the polarization axis of the polarization maintaining substrate layer and the polarization axis of the linearly polarized light emitted by the polarized light emitting device, and the polarization axis of the second polarizer is perpendicular to the polarization axis of the polarization maintaining substrate layer and the polarization axis of the linearly polarized light emitted by the polarized light emitting device.

[0021] Advantages of the present application:

[0022] The present application provides a backlight module, by setting the backlight module comprising an optical film, the optical film comprising a polarization maintaining substrate layer, the optical film is disposed on the side of the polarized light guide plate away from the bottom plate, the optical film comprising a polarization maintaining substrate layer, the polarization axis of the polarization maintaining substrate layer is parallel to the polarization axis of the linearly polarized light emitted by the polarized light emitting device, the polarization maintaining substrate layer can maintain the polarization state of the light emitted from the polarized light guide plate, reduce the loss of the polarized light generated by the polarized light emitting device in the transmission process, improve the utilization rate of the light generated by the polarized light emitting device, thereby improving the light efficiency of the display device.

[0023] The display device provided by the application comprises a backlight module, the backlight module comprises an optical film, the optical film is arranged on the side of the polarization light guide plate away from the bottom plate, the optical film comprises a polarization maintaining substrate layer, the polarization axis of the first polarizing plate is parallel to the polarization axis of the polarization maintaining substrate layer and the polarization axis of linearly polarized light emitted by the polarization light emitting device, the polarization axis of the second polarizing plate is perpendicular to the polarization axis of the polarization maintaining substrate layer and the polarization axis of linearly polarized light emitted by the polarization light emitting device, the polarization maintaining substrate layer can maintain the polarization state of light emitted from the polarization light guide plate, reduce the loss of polarized light generated by the polarization light emitting device in the transmission process, improve the utilization rate of light generated by the polarization light emitting device, and thus improve the light efficiency of light emitted by the display device. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 FIG. 1 is a top view of the display device of the application;

[0025] Figure 2 FIG. 2 is a schematic view of A-A' of the display device shown in FIG. 1; Figure 1

[0026] Figure 3 FIG. 3 is a schematic view of the backlight module of the display device of the application;

[0027] Figure 4 FIG. 4 is a schematic view of the polarization light emitting device of the light bar of the backlight module of the display device of the application;

[0028] Figure 5 FIG. 5 is a schematic view of the position relationship between the optical film and the first anti-reflection layer of the backlight module of the display device of the application.

[0029] BRIEF DESCRIPTION OF DRAWINGS

[0030] 10-display device; 100-backlight module, 110-back plate, 111-bottom plate, 112-side plate, 113-housing cavity, 120-light bar, 121-polarization light emitting device, 1211-substrate, 1212-active layer, 1213-photonic crystal layer, 1214-second anti-reflection layer, 130-polarization light guide plate, 140-optical film, 141-polarization maintaining substrate layer; 150-first anti-reflection layer, 160-anti-reflection layer, 170-polarization reflection layer; 200-liquid crystal display panel; 300-first polarizing plate; 400-second polarizing plate. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the application will be described below in combination with the drawings of the embodiments of the application. The technical solutions described below are only used to explain and illustrate the idea of the application, and should not be regarded as limiting the protection scope of the application. ​

[0032] In addition, the terms "first", "second", and similar terms do not denote any order, quantity, or importance, but are used to distinguish different technical features. The term "multiple" and similar terms mean two or more, unless otherwise explicitly limited.

[0033] The first embodiment of the present application provides a backlight module 100, referring to Figure 3 The display module includes a back plate 110, a light bar 120, a polarized light guide plate 130, and an optical film 140. The back plate 110 includes a bottom plate 111 and a side plate 112 connected to the bottom plate 111 and enclosing a receiving cavity 113. The light bar 120 is fixed to the side plate 112, and the light bar 120 includes a plurality of polarized light emitting devices 121 arranged at intervals. The polarized light guide plate 130 is arranged in the receiving cavity 113, and the light-in side of the polarized light guide plate 130 is close to the light-out side of the light bar 120. The optical film 140 is arranged on the side of the polarized light guide plate 130 away from the bottom plate 111, and the optical film 140 includes a polarization-maintaining base layer 141, and the polarization axis of the polarization-maintaining base layer 141 is parallel to the polarization axis of the linearly polarized light emitted by the polarized light emitting device 121.

[0034] The backlight module 100 of the display device 10 of the conventional scheme emits non-polarized light, and when the non-polarized light passes through the polarizing film, a large amount of light is blocked by the polarizing film, resulting in low light efficiency of the light emitted by the display device 10. Therefore, the technical solution of the present application provides a backlight module 100, which includes an optical film 140, the optical film 140 includes a polarization-maintaining base layer 141, the optical film 140 is arranged on the side of the polarized light guide plate 130 away from the bottom plate 111, the optical film 140 includes a polarization-maintaining base layer 141, and the polarization axis of the polarization-maintaining base layer 141 is parallel to the polarization axis of the linearly polarized light emitted by the polarized light emitting device 121. The polarization-maintaining base layer 141 can maintain the polarization state of the light emitted from the polarized light guide plate 130, reduce the loss of the polarized light generated by the polarized light emitting device 121 during transmission, and improve the utilization rate of the light generated by the polarized light emitting device 121, thereby improving the light efficiency of the light emitted by the display device 10.

[0035] In the present embodiment, the optical film 140 further includes a diffusion layer and a prism layer, the prism layer is arranged on a surface of the polarization-maintaining base layer 141 close to the polarized light guide plate 130, and the diffusion layer is arranged on a surface of the prism layer close to the polarized light guide plate 130.

[0036] In the present embodiment, referring to Figure 3 , Figure 5The backlight module 100 further includes a first anti-reflection layer 150, which is disposed on a surface of the polarization-maintaining substrate layer 141 away from the base plate 111. By including the first anti-reflection layer 150 on the surface of the polarization-maintaining substrate layer 141 away from the base plate 111, the reflection of light on the optical film 140 can be reduced, thereby improving the transmittance of the polarized light-emitting device 121 and thus improving the light emission efficiency of the display device 10.

[0037] In this embodiment, the thickness of the first antireflection layer 150 is 80nm to 100nm. Preferably, the thickness of the first antireflection layer 150 is 80nm, 81nm, 82nm, 83nm, 84mm, 85nm, 86mm, 87nm, 88mm, 89nm, 90mm, 91nm, 92mm, 93nm, 94mm, 95nm, 96mm, 97nm, 98mm, 99nm, or 100mm.

[0038] In this embodiment, the material of the first antireflective layer 150 is at least one of magnesium fluoride, silicon dioxide, silicon dioxide-titanium oxide composite material, or silicon dioxide-zirconia composite material. The first antireflective layer 150 made of magnesium fluoride, silicon dioxide, silicon dioxide-titanium oxide composite material, or silicon dioxide-zirconia composite material has high transmittance and low refractive index.

[0039] In this embodiment, reference Figure 3 , Figure 5 The backlight module 100 further includes an anti-reflection layer 160, which is disposed on the surface of the first anti-reflection layer 150 away from the base plate 111. Because the backlight module 100 of this design is a polarized backlight module 100, when ambient light passes through the liquid crystal display panel of the display device 10 and enters the interior of the display device 10, the light entering the display device 10 is reflected back to the outside and mixes with the polarized light generated by the polarizing light-emitting device 121, causing a reduction in the polarization degree of the light generated by the light-emitting device when passing through the liquid crystal display panel. Therefore, by including the anti-reflection layer 160 on the surface of the first anti-reflection layer 150 away from the base plate 111, the anti-reflection layer 160 can reduce the reflection of ambient light by the optical film 140, preventing reflected ambient light from interfering with the transmission of polarized light, thereby improving the light emission efficiency of the display device 10.

[0040] In the embodiment, the thickness of the anti-reflection layer 160 is 80nm-100nm. Preferably, the thickness of the anti-reflection layer 160 is 80nm, 81nm, 82mm, 83nm, 84mm, 85nm, 86mm, 87nm, 88mm, 89nm, 90mm, 91nm, 92mm, 93nm, 94mm, 95nm, 96mm, 97nm, 98mm, 99nm or 100mm.

[0041] In the embodiment, the material of the anti-reflection layer 160 is nano-porous aluminum oxide. By setting the material of the anti-reflection layer 160 as nano-porous aluminum oxide, the nano-structure of the anti-reflection layer 160 with nano-porous aluminum oxide material can effectively reduce the reflection of the optical film 140 to the ambient light, thereby avoiding the interference of the reflected ambient light to the transmission of the polarized light.

[0042] In the embodiment, referring to Figure 4 , the polarized light emitting device 121 comprises a substrate 1211, an active layer 1212 and a photonic crystal layer 1213; the active layer 1212 is arranged on the substrate 1211; the photonic crystal layer 1213 is arranged on a surface of the active layer 1212 away from the substrate 1211. By setting the polarized light emitting device 121 comprising a substrate 1211, an active layer 1212 and a photonic crystal layer 1213; the active layer 1212 is arranged on the substrate 1211; the photonic crystal layer 1213 is arranged on a surface of the active layer 1212 away from the substrate 1211, the band gap characteristics of the photonic crystal can effectively extract the polarized light generated by the polarized light emitting device 121 to the outside, thereby improving the polarization degree of the polarized light generated by the backlight module 100.

[0043] In the embodiment, the substrate 1211 is a sapphire substrate 1211.

[0044] In the embodiment, the quantum well of the active layer 1212 comprises an InGaN quantum well structure or a GaN quantum well structure.

[0045] In the embodiment, the quantum well of the active layer 1212 comprises an InGaN quantum well structure or a GaN quantum well structure.

[0046] In the embodiment, the polarized light-emitting device 121 further comprises a second antireflection layer 1214, which is arranged on a surface of the photonic crystal layer 1213 away from the substrate 1211. By arranging the polarized light-emitting device 121 further comprising a second antireflection layer 1214, which is arranged on a surface of the photonic crystal layer 1213 away from the substrate 1211, the second antireflection layer 1214 can reduce the loss of light generated on the surface of the photonic crystal layer 1213, thereby facilitating the improvement of the light efficiency of the light emitted by the display device 10.

[0047] In the embodiment, the material of the second antireflection layer 1214 comprises silicon dioxide. Among them, the second antireflection layer 1214 with the material of silicon dioxide has high transmittance and low refractive index.

[0048] In the embodiment, the material of the polarization-maintaining substrate layer 141 comprises cycloolefin polymer or polymethyl methacrylate. By arranging the material of the polarization-maintaining substrate layer 141 to comprise cycloolefin polymer or polymethyl methacrylate, the polarization-maintaining substrate layer 141 with the material of cycloolefin polymer or polymethyl methacrylate has high birefringence and low absorption loss, so that the polarization-maintaining substrate layer 141 can effectively maintain the polarization state of the polarized light from the polarized light-emitting device 121, thereby reducing the loss of the polarized light in the transmission process and improving the light efficiency of the light emitted by the display device 10.

[0049] In the embodiment, referring to Figure 3 , the backlight module 100 further comprises a polarized reflection layer 170, which is arranged on a surface of the polarized light guide plate 130 close to the bottom plate 111. By arranging the backlight module 100 further comprising a polarized reflection layer 170, which is arranged on a surface of the polarized light guide plate 130 close to the bottom plate 111, on the one hand, the polarized reflection layer 170 can reflect the polarized light, so that part of the light generated by the polarized light-emitting device 121 can be emitted in the direction of the liquid crystal display panel of the display device 10 under the action of the polarized reflection layer 170, on the other hand, the polarized reflection layer 170 can maintain the polarization state of the polarized light, thereby improving the polarization degree of the light of the backlight module 100.

[0050] In the embodiment, the polarized reflection layer 170 has a light transmission axis parallel to the polarization axis of the polarization-maintaining substrate layer 141.

[0051] In the embodiment, the material of the polarization light guide plate 130 includes polymethyl methacrylate. By setting the material of the polarization light guide plate 130 to include polymethyl methacrylate, the polarization light guide plate 130 with the material of polymethyl methacrylate has high birefringence and low absorption loss, so that the polarization light guide plate 130 can effectively maintain the polarization state of the polarized light from the polarized light emitting device 121, thereby reducing the loss of the polarized light in the transmission process and improving the light efficiency of the light emitted by the display device 10.

[0052] The second embodiment of the present application provides a display device 10, which refers to Figure 1 、 Figure 2 The display device 10 includes the backlight module 100, and further includes a liquid crystal display panel 200, a first polarizer 300 and a second polarizer 400. The liquid crystal display panel 200 is arranged on the light emitting side of the backlight module 100. The first polarizer 300 is arranged on a surface of the liquid crystal display panel 200 close to the backlight module 100. The second polarizer 400 is arranged on a surface of the liquid crystal display panel 200 away from the backlight module 100. The polarization axis of the first polarizer is parallel to the polarization axis of the polarization maintaining base layer 141 and the polarization axis of the linearly polarized light emitted by the polarized light emitting device 121. The polarization axis of the second polarizer 400 is perpendicular to the polarization axis of the polarization maintaining base layer 141 and the polarization axis of the linearly polarized light emitted by the polarized light emitting device 121.

[0053] The backlight module 100 of the display device 10 of the conventional scheme emits non-polarized light. When the non-polarized light passes through the polarizer, a large amount of light is blocked by the polarizer, resulting in low light efficiency of the light emitted by the display device 10. Therefore, the technical scheme of the present application provides a display device 10, which includes a backlight module 100. The backlight module 100 includes an optical film 140. The optical film 140 is arranged on the side of the polarization light guide plate 130 away from the bottom plate 111. The optical film 140 includes a polarization maintaining base layer 141. The polarization axis of the first polarizer 300 is parallel to the polarization axis of the polarization maintaining base layer 141 and the polarization axis of the linearly polarized light emitted by the polarized light emitting device 121. The polarization axis of the second polarizer 400 is perpendicular to the polarization axis of the polarization maintaining base layer 141 and the polarization axis of the linearly polarized light emitted by the polarized light emitting device 121. The polarization maintaining base layer 141 can maintain the polarization state of the light emitted from the polarization light guide plate 130, reduce the loss of the polarized light emitted by the polarized light emitting device 121 in the transmission process, improve the utilization rate of the light emitted by the polarized light emitting device 121, and thereby improve the light efficiency of the light emitted by the display device 10.

[0054] In the embodiment, the display device 10 is a polarization display device.

[0055] The specific implementation of the present application is described in detail above. The above-described embodiments disclosed by the present application are only preferred embodiments of the present application, and many variations and improvements can be made by those of ordinary skill in the art without departing from the concept of the present application. These variations and improvements are all within the scope of protection of the claims of the present application.

Claims

1. A backlight module, characterized in that, include: A back panel, comprising a bottom plate and side plates, wherein the side plates are connected to the bottom plate and form a receiving cavity; A light strip, which is fixed to the side plate, includes multiple polarized light-emitting devices, which are spaced apart. A polarizing light guide plate is disposed within the receiving cavity, with the light-incident side of the polarizing light guide plate close to the light-outceasing side of the lamp strip; An optical film is disposed on the side of the polarizing light guide plate away from the base plate. The optical film includes a polarization-maintaining substrate layer, the polarization axis of which is parallel to the polarization axis of the linearly polarized light emitted by the polarizing light-emitting device.

2. The backlight module according to claim 1, characterized in that, The backlight module further includes a first anti-reflection layer, which is disposed on a surface of the polarization-maintaining substrate layer away from the base plate.

3. The backlight module according to claim 2, characterized in that, The material of the first antireflective layer is at least one of magnesium fluoride, silicon dioxide, silicon dioxide-titanium oxide composite material, or silicon dioxide-zirconia composite material.

4. The backlight module according to claim 2, characterized in that, The backlight module also includes an anti-reflective layer, which is disposed on a surface of the first anti-reflective layer away from the base plate.

5. The backlight module according to claim 4, characterized in that, The anti-reflective layer is made of nanoporous alumina.

6. The backlight module according to any one of claims 1-5, characterized in that, The polarized light-emitting device includes: Substrate; An active layer is disposed on the substrate; A photonic crystal layer, wherein the active layer of the photonic crystal layer is located on a surface away from the substrate.

7. The backlight module according to claim 6, characterized in that, The polarized light-emitting device further includes a second anti-reflection layer, which is disposed on a surface of the photonic crystal layer away from the substrate.

8. The backlight module according to claim 1, characterized in that, The material of the polarization-maintaining substrate layer includes cyclic olefin polymers or polymethyl methacrylate.

9. The backlight module according to claim 1, characterized in that, The backlight module also includes a polarization reflection layer, which is disposed on a surface of the polarization light guide plate near the base plate.

10. A display device, characterized in that, The display device includes a liquid crystal display panel, a first polarizer, a second polarizer, and a backlight module as described in any one of claims 1-9. The liquid crystal display panel is disposed on the light-emitting side of the backlight module. The first polarizer is disposed on a surface of the liquid crystal display panel near the backlight module. The second polarizer is disposed on a surface of the liquid crystal display panel away from the backlight module. The polarization axis of the first polarizer is parallel to the polarization axis of the polarization-maintaining substrate layer and the polarization axis of the linearly polarized light emitted by the polarized light-emitting device. The polarization axis of the second polarizer is perpendicular to the polarization axis of the polarization-maintaining substrate layer and the polarization axis of the linearly polarized light emitted by the polarized light-emitting device.

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