Direct type backlight module
By introducing an electrochromic layer into the direct-lit backlight module, the problems of insufficient light mixing and light leakage between adjacent light-emitting elements are solved, resulting in a more uniform surface light source and higher contrast.
Patent Information
- Application Number
- CN202410972861.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2026-01-20
AI Technical Summary
In existing direct-lit backlight modules, the spacing between adjacent light-emitting elements results in insufficient light mixing, creating dark areas and potentially causing light leakage.
An electrochromic layer is introduced into the direct-lit backlight module. By controlling the voltage between the transparent conductive layers, the electrochromic layer is black when the auxiliary light-emitting element is off to avoid light leakage; and transparent when the auxiliary light-emitting element is on to enhance brightness.
It effectively reduces light leakage and improves the uniformity and contrast of the surface light source.
Smart Images
Figure CN121364577A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a direct backlight module, in particular, to a direct backlight module comprising an electrochromic layer. BACKGROUND
[0002] The existing backlight module is divided into side-in backlight module and direct backlight module according to the different incident positions of light source. The side-in backlight module is to set the light emitting element on the side of the light guide plate located at the back of the display panel, the light emitted by the light emitting element enters the light guide plate from the side of the light guide plate, and then is reflected and diffused to be emitted from the light guide plate, and then passes through the optical film to form a surface light source to provide the display panel. The direct backlight module is to set multiple light emitting elements directly on the back of the display panel, and then directly form a surface light source to provide the display panel.
[0003] However, the interval between adjacent light emitting elements will form a dark area due to insufficient light mixing, resulting in poor uniformity of the surface light source. If the auxiliary light emitting element is arranged between the intervals of the adjacent main light emitting elements, when only the main light emitting element is turned on or both the main light emitting element and the auxiliary light emitting element are turned off, reflection light may be generated to cause light leakage. SUMMARY
[0004] At least one embodiment of the present application provides a direct backlight module capable of reducing light leakage.
[0005] At least one embodiment of the present application provides a direct backlight module, which comprises a substrate, a plurality of main light emitting elements and a plurality of auxiliary light emitting elements. The substrate comprises a first transparent substrate, a first transparent conductive layer, an ion storage layer, an electrolyte layer, an electrochromic layer, a second transparent conductive layer and a second transparent substrate. The first transparent substrate has a first surface, the first transparent conductive layer is arranged on the first transparent substrate, the ion storage layer is arranged on the first transparent conductive layer, the electrolyte layer is arranged on the ion storage layer, the electrochromic layer is arranged on the electrolyte layer, the second transparent conductive layer is arranged on the electrochromic layer, and the second transparent substrate is arranged on the second transparent conductive layer and has a second surface opposite to the first surface. The plurality of main light emitting elements are arranged on the second surface and are arranged at intervals, and the plurality of auxiliary light emitting elements are arranged on the first surface and are arranged at intervals.
[0006] In at least one embodiment of the present application, when the plurality of auxiliary light emitting elements are turned off, the electrochromic layer is black; and when the plurality of auxiliary light emitting elements are turned on, the color of the electrochromic layer is transparent.
[0007] In at least one embodiment of the present application, the oxidized state of the electrochromic layer is black, and the reduced state of the electrochromic layer is transparent.
[0008] In at least one embodiment of the present application, the material of the first transparent substrate and the material of the second transparent substrate comprise polyester-based polymer compounds.
[0009] In at least one embodiment of the present application, the material of the first transparent substrate and the material of the second transparent substrate comprise polyethylene terephthalate, polyimide, polyethylene naphthalate, or a combination thereof.
[0010] In at least one embodiment of the present application, the material of the first transparent conductive layer and the material of the second transparent conductive layer comprise indium tin oxide, tin oxide, tin antimony oxide, graphene, conductive polymer material, or a combination thereof.
[0011] In at least one embodiment of the present application, the material of the electrolyte layer comprises lithium perchlorate, sodium perchlorate, or a combination thereof.
[0012] In at least one embodiment of the present application, the material of the electrochromic layer comprises polypyrrole, polyaniline, polyazulene, polythiophene, polyindole, polycarbazole, or a combination thereof.
[0013] In at least one embodiment of the present application, the direct type backlight module further comprises a diffusion plate, the plurality of main light emitting elements are located between the substrate and the diffusion plate, any two adjacent main light emitting elements have a first interval, any two adjacent auxiliary light emitting elements have a second interval, on the normal line of the substrate, the plurality of main light emitting elements respectively overlap with a plurality of second intervals, the plurality of auxiliary light emitting elements respectively overlap with a plurality of first intervals, and the light emitting surfaces of the plurality of main light emitting elements and the light emitting surfaces of the plurality of auxiliary light emitting elements all face the diffusion plate.
[0014] In at least one embodiment of the present application, the direct type backlight module further comprises a diffusion plate and a reflection plate, the plurality of main light emitting elements are located between the substrate and the diffusion plate, the plurality of auxiliary light emitting elements are located between the reflection plate and the substrate, any two adjacent main light emitting elements have a first interval, any two adjacent auxiliary light emitting elements have a second interval, on the normal line of the substrate, a plurality of first intervals respectively overlap with a plurality of second intervals, the light emitting surfaces of the plurality of main light emitting elements face the diffusion plate, and the light emitting surfaces of the plurality of auxiliary light emitting elements face the reflection plate. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 is a partial cross-sectional schematic view of a direct type backlight module according to at least one embodiment of the present application.
[0016] Figure 2 is a partial cross-sectional schematic view of a direct type backlight module according to at least one other embodiment of the present application.
[0017] Figures 3A to 3Cis a top view of a direct backlight module according to at least one embodiment of the present application.
[0018] Figures 4A to 4G is Figure 1 partial cross-sectional views of a direct backlight module according to at least one embodiment of the present application at different process stages. DETAILED DESCRIPTION
[0019] In the following detailed description of the application, for purposes of clarity and explanation, the dimensions of the elements in the drawings (such as layers, films, substrates, and regions) are not to scale and the number of elements can be reduced for clarity. Accordingly, the description and explanation of the embodiments below are not limited, for purposes of explanation, to the precise number of elements and the precise arrangements and configurations shown in the drawings. For example, the flat surfaces shown in the drawings can have rough and / or nonlinear features, and the sharp corners shown in the drawings can be rounded. Thus, the elements shown in the drawings are meant to be illustrative only and are not meant to be limiting in terms of the scope of the application.
[0020] Second, the use of words like "about", "approximately", or "substantially" when used in this disclosure indicates that the value of a numerical parameter so modified is "within the range of values that one of ordinary skill in the art would consider in developing a novel system as described herein. Such ranges include the known tolerances, variations and / or imperfections in the components or the values that would be expected to occur by ordinary skill in the art making measurements.
[0021] Spatially relative terms, such as "beneath", "below", "lower", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device described is turned over and the bottom surface becomes the top surface, portions described as "below" other portions can then be "above" other portions. Likewise, the spatially relative terms can encompass the various
[0022] It should be understood that, although the terms "first", "second", "third" etc. can be used herein to describe various elements or
[0023] Although the present application is illustrated by way of a series of operations or steps in the manufacturing method, the order of the operations or steps shown should not be construed as limiting the present application. For example, certain operations or steps can be performed in a different order and / or simultaneously with other steps. In addition, each operation or step described herein can include several sub-steps or actions.
[0024] In addition, the present application can be implemented or applied by other different embodiments, and the details of the present application can be combined, modified and changed in various embodiments without departing from the spirit of the present application.
[0025] Figure 1 is a partial cross-sectional schematic view of a direct backlight module 10 according to at least one embodiment of the present application. Referring to Figure 1 The direct backlight module 10 includes a substrate 100, a plurality of primary light emitting elements 200 and a plurality of auxiliary light emitting elements 300. The substrate 100 includes a first transparent substrate 102, a first transparent conductive layer 104, an ion storage layer 106, an electrolyte layer 108, an electrochromic layer 110, a second transparent conductive layer 112 and a second transparent substrate 114.
[0026] The first transparent substrate 102 has a first surface S1, the first transparent conductive layer 104 is disposed on the first transparent substrate 102, the ion storage layer 106 is disposed on the first transparent conductive layer 104, the electrolyte layer 108 is disposed on the ion storage layer 106, the electrochromic layer 110 is disposed on the electrolyte layer 108, the second transparent conductive layer 112 is disposed on the electrochromic layer 110, and the second transparent substrate 114 is disposed on the second transparent conductive layer 112 and has a second surface S2 opposite to the first surface S1. The plurality of primary light emitting elements 200 are disposed on the second surface S2 and arranged at intervals, and the plurality of auxiliary light emitting elements 300 are disposed on the first surface S1 and arranged at intervals.
[0027] Since the electrochromic layer 110 is disposed between the main light emitting elements 200 and the auxiliary light emitting elements 300, by controlling the voltage between the first transparent conductive layer 104 and the second transparent conductive layer 112, it can be determined whether the electrochromic layer 110 is discolored. When only the main light emitting elements 200 are turned on or both the main light emitting elements 200 and the auxiliary light emitting elements 300 are turned off, the electrochromic layer 110 can be turned black to avoid light leakage caused by reflected light, increase the blackness of the space between the main light emitting elements 200, and improve the contrast. However, when the auxiliary light emitting elements 300 are turned on to enhance brightness, the electrochromic layer 110 is transparent to allow the light of the auxiliary light emitting elements 300 to pass through.
[0028] Please continue to refer to Figure 1 , the direct backlight module 10 further includes a diffusion plate 400, and the plurality of main light emitting elements 200 are located between the substrate 100 and the diffusion plate 400. Any two adjacent main light emitting elements 200 have a first interval I1, and any two adjacent auxiliary light emitting elements 300 have a second interval I2. On the normal line of the substrate 100, the plurality of main light emitting elements 200 respectively overlap the plurality of second intervals I2, and the plurality of auxiliary light emitting elements 300 respectively overlap the plurality of first intervals I1. The light emitting surface E1 of the main light emitting element 200 and the light emitting surface E2 of the auxiliary light emitting element 300 both face the diffusion plate 400.
[0029] In order to make the expression of the drawings more simple, Figure 1 only three main light emitting elements 200 and two auxiliary light emitting elements 300 are shown. However, other main light emitting elements 200 and auxiliary light emitting elements 300 can also be included in places not shown in the figure.
[0030] As shown by the dashed arrow in Figure 1 , when both the main light emitting elements 200 and the auxiliary light emitting elements 300 are turned on, the light emitted from the light emitting surface E1 of the main light emitting element 200 will enter the diffusion plate 400, and the light emitted from the light emitting surface E2 of the auxiliary light emitting element 300 will pass through the substrate 100 and enter the diffusion plate 400 through the first interval I1. That is, when the auxiliary light emitting elements 300 are turned on, the electrochromic layer 110 is transparent to allow the light emitted by the auxiliary light emitting elements 300 to pass through the substrate 100. In some embodiments, the reduced state of the electrochromic layer 110 is transparent.
[0031] However, when only the main light emitting elements 200 are turned on or both the main light emitting elements 200 and the auxiliary light emitting elements 300 are turned off, that is, when the auxiliary light emitting elements 300 are turned off, the electrochromic layer 110 is black to prevent the light reflected by the auxiliary light emitting elements 300 from passing through the substrate 100 and thus avoid light leakage caused by reflected light. In some embodiments, the oxidized state of the electrochromic layer 110 is black.
[0032] In some embodiments, the material of the electrochromic layer 110 can include polypyrole, polyaniline, polyazulene, polythiophene, polyindole, polycarbazole, or a combination thereof.
[0033] For example, polypyrole can be used as the material of the electrochromic layer 110, which has a lower oxidation potential, a higher current efficiency, and a longer repeatable life than other materials, and thus can have a higher stability and improve the reliability of the direct backlight module 10. In addition, the color of polypyrole when oxidized is black, which is different from other materials that can be green or dark red. The oxidation color of the material of the electrochromic layer 110 is black, which can increase the visual blackness of the display.
[0034] In some embodiments, the first transparent substrate 102 and the second transparent substrate 114 can include driving lines (not shown) for driving the main light emitting element 200 and the auxiliary light emitting element 300. The material of the first transparent substrate 102 and the material of the second transparent substrate 114 can include polyester-based high molecular compounds. The material of the first transparent substrate 102 and the material of the second transparent substrate 114 can include polyethylene terephthalate (PET), polyimide (PI), polyethylene naphthalate (PEN), or a combination thereof. The material of the first transparent conductive layer 104 and the material of the second transparent conductive layer 112 include indium tin oxide, tin oxide, antimony tin oxide, graphene, conductive polymer materials, or a combination thereof. By selecting the above-mentioned materials, the transmittance of the light emitted by the auxiliary light emitting element 300 through the substrate 100 can be effectively improved when the electrochromic layer 110 is transparent.
[0035] The material of the electrolyte layer 108 can include lithium perchlorate, sodium perchlorate, or other electrolyte materials, and the ion storage layer 106 is used to store ions with opposite charges when the electrochromic layer 110 undergoes redox reaction, thereby maintaining charge balance. The diffusion plate 400 can include diffusion microstructures or diffusion particles to uniformly diffuse the light to form a surface light source.
[0036] The main light-emitting element 200 and the auxiliary light-emitting element 300 can be light-emitting diodes (LEDs), such as mini LEDs or micro LEDs (μLEDs). Micro LEDs have a thickness of less than 10 micrometers, for example, 6 micrometers. Mini LEDs can be divided into two types: one with encapsulant and the other without. Mini LEDs with encapsulant can have a thickness of less than 800 micrometers, while those without encapsulant can have a thickness of less than 100 micrometers. Furthermore, the main light-emitting element 200 and the auxiliary light-emitting element 300 can also be large-size regular LEDs other than mini LEDs and micro LEDs; therefore, the main light-emitting element 200 and the auxiliary light-emitting element 300 are not limited to small mini LEDs or micro LEDs.
[0037] Figure 2 This is a partial cross-sectional schematic diagram of a direct-lit backlight module 10A according to at least another embodiment of the present invention. Figure 2 Implementation examples and Figure 1 Most of the components in the embodiments are the same in terms of structure, material and relative position, so the same technical features will not be described again here. Figure 2 Implementation examples and Figure 1 The main difference in the embodiments is that, Figure 2 The direct-lit backlight module 10A also includes a reflector 500. In some embodiments, the reflector 500 may be made of metal.
[0038] Please see Figure 2 Multiple auxiliary light-emitting elements 300 are located between the reflector 500 and the substrate 100. There is a first interval I1 between any two adjacent main light-emitting elements 200 and a second interval I2 between any two adjacent auxiliary light-emitting elements 300. On the normal line of the substrate 100, the multiple first intervals I1 overlap with the multiple second intervals I2 respectively. The light-emitting surface E1 of the main light-emitting element 200 faces the diffuser 400, while the light-emitting surface E2 of the auxiliary light-emitting element 300 faces the reflector 500.
[0039] like Figure 2 As indicated by the dashed arrow, when both the main light-emitting element 200 and the auxiliary light-emitting element 300 are turned on, the light emitted from the light-emitting surface E1 of the main light-emitting element 200 will enter the diffuser plate 400, and the light emitted from the light-emitting surface E2 of the auxiliary light-emitting element 300 will be reflected by the reflector plate 500, pass through the substrate 100 through the second gap I2, and enter the diffuser plate 400 through the first gap I1. That is, when the auxiliary light-emitting element 300 is turned on, the electrochromic layer 110 becomes transparent so that the light emitted by the auxiliary light-emitting element 300 can pass through the substrate 100.
[0040] However, when only the main light emitting element 200 is turned on or both the main light emitting element 200 and the auxiliary light emitting element 300 are turned off, i.e., when the auxiliary light emitting element 300 is turned off, the electrochromic layer 110 is black so that the light reflected by the reflecting plate 500 does not pass through the substrate 100, thereby avoiding light leakage caused by the reflected light.
[0041] In other embodiments, the light emitting direction of the auxiliary light emitting element 300 can also be other directions, as long as the angle and spacing between the auxiliary light emitting element 300 and the reflecting plate 500 are changed, the light emitted by the auxiliary light emitting element 300 can be emitted from the first interval I1 between two adjacent main light emitting elements 200, and the dark area caused by insufficient mixed light between the two adjacent main light emitting elements 200 can be compensated for in brightness.
[0042] Figures 3A to 3C is a top view of a direct backlight module according to at least one embodiment of the present application. Please refer to Figure 3A , the plurality of main light emitting elements 200 of the direct backlight module 10 are arranged in an array along a first direction D1 and a second direction D2 substantially perpendicular to the first direction D1, the plurality of auxiliary light emitting elements 300 are arranged in an array along the first direction D1 and the second direction D2 substantially perpendicular to the first direction D1, and the plurality of main light emitting elements 200 and the plurality of auxiliary light emitting elements 300 are arranged alternately along the first direction D1 and the second direction D2.
[0043] Please refer to Figure 3B , Figure 3B The relative position relationship of most elements of the embodiment of Figure 3A is the same as that of the embodiment of Figure 3B The difference between the embodiment of Figure 3A and the embodiment of Figure 3B is that the plurality of main light emitting elements 200 and the plurality of auxiliary light emitting elements 300 of the direct backlight module 10' are arranged alternately along a third direction D3 which forms an acute angle with the first direction D1. In some embodiments, the acute angle between the third direction D3 and the first direction D1 can be 45 degrees.
[0044] Please refer to Figure 3C , Figure 3C The relative position relationship of most elements of the embodiment of Figure 3A is the same as that of the embodiment of Figure 3C The difference between the embodiment of Figure 3A and the embodiment of Figure 3CThe plurality of primary light emitting elements 200 of the direct-lit backlight module 10A are respectively arranged corresponding to the plurality of auxiliary light emitting elements 300, i.e. on the normal line of the substrate 100, the plurality of primary light emitting elements 200 respectively overlap the plurality of auxiliary light emitting elements 300.
[0045] Figures 4A to 4G is Figure 1 Partial cross-sectional views of the direct-lit backlight module 10 at different process stages. Please refer to Figure 4A , a first transparent substrate 102 is provided and a first transparent conductive layer 104 is formed on the first transparent substrate 102.
[0046] Please refer to Figures 4B to 4E , an ion storage layer 106, an electrolyte layer 108, an electrochromic layer 110 and a second transparent conductive layer 112 are sequentially formed on the first transparent conductive layer 104. In detail, first, as shown in Figure 4B , the ion storage layer 106 is formed on the first transparent conductive layer 104. Then, as shown in Figure 4C , the electrolyte layer 108 is formed on the ion storage layer 106. As shown in Figure 4D , the electrochromic layer 110 is formed on the electrolyte layer 108. Then, as shown in Figure 4E , the second transparent conductive layer 112 is formed on the electrochromic layer 110.
[0047] In some embodiments, the ion storage layer 106, the electrolyte layer 108 and the electrochromic layer 110 can be formed by a coating process and a baking process. The first transparent conductive layer 104 and the second transparent conductive layer 112 can be formed by a coating process and a baking process or a photo-curing process.
[0048] Please refer to Figure 4F , a second transparent substrate 114 is formed on the second transparent conductive layer 112 to form the substrate 100. Please refer to Figure 4G , the primary light emitting elements 200 and the auxiliary light emitting elements 300 are respectively fixed on the two opposite surfaces S2, S1 of the substrate 100. Then, the diffusion plate 400 is arranged on the primary light emitting elements 200 to form the direct-lit backlight module 10 as shown in Figure 1 . In some embodiments, the second transparent substrate 114 can be formed on the second transparent conductive layer 112 by a pressing process, and the primary light emitting elements 200 and the auxiliary light emitting elements 300 can be fixed by a pick-and-place process.
[0049] In summary, in the direct backlight module according to at least one of the embodiments of the present application, the electrochromic layer is arranged between the main light emitting element and the auxiliary light emitting element, and the voltage between the two transparent conductive layers arranged on both sides of the electrochromic layer can determine whether the electrochromic layer is discolored. When only the main light emitting element is turned on or both the main light emitting element and the auxiliary light emitting element are turned off, the electrochromic layer can be turned black to avoid light leakage caused by reflected light.
[0050] Although the present application has been disclosed with reference to the embodiments above, it is not intended to limit the present application, and those skilled in the art can make some changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of the present application is defined by the appended claims.
[0051]
Symbol Description
[0052] 10, 10', 10A: direct backlight module
[0053] 100: substrate
[0054] 102: first transparent substrate
[0055] 104: first transparent conductive layer
[0056] 106: ion storage layer
[0057] 108: electrolyte layer
[0058] 110: electrochromic layer
[0059] 112: second transparent conductive layer
[0060] 114: second transparent substrate
[0061] 200: main light emitting element
[0062] 300: auxiliary light emitting element
[0063] 400: diffusion plate
[0064] 500: reflection plate
[0065] D1: first direction
[0066] D2: second direction
[0067] D3: third direction
[0068] E1, E2: light exit surface
[0069] I1: first interval
[0070] I2: second interval
[0071] S1: first surface
[0072] S2: second surface.
Claims
1. A direct backlight module, characterized in that, Comprising: a substrate, comprising: a first transparent substrate having a first surface; a first transparent conductive layer disposed on the first transparent substrate; an ion storage layer disposed on the first transparent conductive layer; an electrolyte layer disposed on the ion storage layer; an electrochromic layer disposed on the electrolyte layer; a second transparent conductive layer disposed on the electrochromic layer; and a second transparent substrate disposed on the second transparent conductive layer and having a second surface opposite to the first surface; a plurality of primary light emitting elements disposed on the second surface and arranged at intervals; and a plurality of auxiliary light emitting elements disposed on the first surface and arranged at intervals. The electrochromic layer is black when the plurality of auxiliary light emitting elements are off, and the electrochromic layer is transparent when the plurality of auxiliary light emitting elements are on. The electrochromic layer is black in oxidized state and transparent in reduced state.
2. The direct-lit backlight module of claim 1, wherein, The material of the first transparent substrate and the material of the second transparent substrate comprise polyester polymer compounds.
3. The direct-lit backlight module of claim 2, wherein, The material of the first transparent substrate and the material of the second transparent substrate comprise polyethylene terephthalate, polyimide, polyethylene naphthalate, or a combination thereof.
4. The direct-lit backlight module of claim 1, wherein, The material of the first transparent conductive layer and the material of the second transparent conductive layer comprise indium tin oxide, tin oxide, tin antimony oxide, graphene, conductive polymer material, or a combination thereof.
5. The direct-lit backlight module of claim 1, wherein, The material of the electrolyte layer comprises lithium perchlorate, sodium perchlorate, or a combination thereof.
6. The direct-lit backlight module of claim 1, wherein, The material of the electrochromic layer comprises polypyrrole, polyaniline, polyazulene, polythiophene, polyindole, polycarbazole, or a combination thereof.
7. The direct-lit backlight module of claim 1, wherein, Further comprising a diffusion plate, wherein the plurality of primary light emitting elements are located between the substrate and the diffusion plate, wherein a first interval is between any two adjacent primary light emitting elements, a second interval is between any two adjacent auxiliary light emitting elements, on the normal line of the substrate, the plurality of primary light emitting elements respectively overlap with the plurality of second intervals, the plurality of auxiliary light emitting elements respectively overlap with the plurality of first intervals, and the light emitting surface of the plurality of primary light emitting elements and the light emitting surface of the plurality of auxiliary light emitting elements both face the diffusion plate.
8. The direct-lit backlight module of claim 1, wherein, Further comprising a diffusion plate and a reflection plate, wherein the plurality of primary light emitting elements are located between the substrate and the diffusion plate, the plurality of auxiliary light emitting elements are located between the reflection plate and the substrate, wherein a first interval is between any two adjacent primary light emitting elements, a second interval is between any two adjacent auxiliary light emitting elements, on the normal line of the substrate, the plurality of first intervals respectively overlap with the plurality of second intervals, the light emitting surface of the plurality of primary light emitting elements faces the diffusion plate, and the light emitting surface of the plurality of auxiliary light emitting elements faces the reflection plate.
9. The direct-lit backlight module of claim 1, wherein, 10. The direct-lit backlight module of claim 1, wherein,