A composite grating structure electroluminescent film

Abstract

The present invention discloses a composite grating structure electroluminescent dimming film, comprising a lower substrate, a planar dimming layer, a grating dimming layer, and an upper substrate, arranged in sequence from bottom to top; the planar dimming layer comprises a lower planar transparent electrode, a dye liquid crystal, and an upper planar transparent electrode, with a flexible filler and a transparent lower spacer provided between the lower substrate and the planar dimming layer; the grating dimming layer comprises at least one level of grating structure, each level of grating structure being provided with an independently controlled grating lower electrode, grating liquid crystal, and grating upper electrode, with an isolation layer provided between adjacent electrodes, and the grating layer flexible filler being filled between the grating structures. The beneficial effects of the present invention are as follows: the composite grating structure electroluminescent film, through layered design and multi-level control, achieves multi-dimensional control from basic shading to precise light diffraction, and has significant application value in the fields of smart glass, display devices, and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of dimming films, and in particular to an electro-dimming film with a composite grating structure. Background Art

[0002] As a core device in the field of intelligent light control, electroluminescent glass uses electric fields to control the optical properties of materials (such as transmittance and diffraction angle). It has broad application prospects in building energy conservation, automotive glass, display devices, and other fields. However, existing technologies still have significant limitations in terms of light control dimensions, structural flexibility, and mode flexibility, as follows:

[0003] Traditional electro-dimming glass typically utilizes a single-layer dimming structure (such as PDLC (polymer dispersed liquid crystal) or SPD (suspended particle device)). This structure controls light transmittance (either transparent or light-blocking) solely through an electric field, but is unable to fine-tune the angular distribution of light (e.g., diffraction or scattering). For example, a car's windshield in bright sunlight must disperse incident light to avoid glare. However, traditional electro-dimming glass only reduces overall transmittance without optimizing light intensity distribution, resulting in insufficient visual comfort.

[0004] Some research has attempted to incorporate grating structures to manipulate light diffraction, but these gratings typically have fixed parameters like period and depth, limiting their operation to specific wavelengths or angles. Even with liquid crystal gratings (dynamic gratings formed by manipulating the arrangement of liquid crystal molecules using an electric field), existing technologies often employ single-stage gratings, producing only a single diffraction pattern (e.g., ±1st-order diffraction), making them difficult to meet the diverse light distribution requirements of various scenarios (e.g., uniform lighting distribution for cinema screens requires the coordinated use of multiple diffraction stages).

[0005] With the increasing popularity of foldable devices and curved glass (such as curved car side windows and foldable phone screens), the demand for flexible dimming glass has increased significantly. However, in traditional dimming structures, the connection between the rigid substrate (such as ordinary glass) and the liquid crystal layer is prone to stress concentration due to bending, resulting in uneven liquid crystal layer thickness or electrode fracture. Furthermore, it is difficult to balance insulation and mechanical stability between multi-layer structures (such as electrode layers and isolation layers), which can easily lead to crosstalk or structural failure during long-term use.

[0006] Based on this, the present invention proposes an electro-luminescent film with a composite grating structure. Summary of the Invention

[0007] The main technical problem solved by the present invention is to provide a composite grating structure electroluminescent film to solve one or more of the above-mentioned problems in the prior art.

[0008] To solve the above technical problems, the present invention adopts a technical solution: a composite grating structure electro-dimming film, the innovation of which is that it includes a lower substrate, a planar dimming layer, a grating dimming layer and an upper substrate arranged in sequence from bottom to top; the planar dimming layer includes a lower planar transparent electrode, a dye liquid crystal and an upper planar transparent electrode, and a flexible filler is provided between the lower substrate and the planar dimming layer; a transparent lower spacer is provided between the lower substrate and the upper planar transparent electrode, and the transparent lower spacer is used to uniformly support the planar dimming layer; the grating dimming layer includes at least two levels of grating structures, each level of the grating structure is provided with an independently controlled grating lower electrode, grating liquid crystal and grating upper electrode, an isolation layer is provided between adjacent electrodes, and the grating layer flexible filler is filled between the grating structures.

[0009] In some embodiments, the grating structure includes a primary grating and a secondary grating.

[0010] In some embodiments, the grating liquid crystal includes a primary grating liquid crystal and a secondary grating liquid crystal.

[0011] In some embodiments, the grating upper electrode includes a primary grating upper electrode and a secondary grating upper electrode.

[0012] In some embodiments, the isolation layer includes a lower electrode isolation layer, a grating layer spacer, and a grating upper electrode isolation layer.

[0013] In some embodiments, the lower substrate and the upper substrate are made of ordinary hard glass, deformable ultra-thin glass, organic PET, PI or TPU material, and the upper and lower substrates are made of the same or different materials.

[0014] In some embodiments, the flexible filler is an organic material such as PDMS or PMMA.

[0015] In some embodiments, the dye liquid crystal is a DPL electroluminescent material.

[0016] In some embodiments, the lower plane transparent electrode, the upper plane transparent electrode, the grating lower electrode, the first-level grating upper electrode, and the second-level grating upper electrode are all conductive polymer PEDOT, ITO, or zinc oxide transparent electrodes.

[0017] In some embodiments, the thickness of the dye liquid crystal layer of the planar dimming layer is greater than 10 micrometers and less than 1.0 mm.

[0018] The beneficial effects of the present invention are: multi-mode dimming capability: independent / cooperative control of the planar layer and the grating layer, covering multiple modes such as transparency, shading, single-order diffraction, multi-order diffraction, etc., and applicable to a wide range of scenarios; high flexibility and stability: the design of the deformable substrate and flexible filler supports curved surface installation and bending use; the structural optimization of the isolation layer and the spacer ensures the dimming consistency of long-term use; efficient light control: the diffraction function of the grating structure can accurately adjust the light intensity distribution, compared with the traditional single-layer dimming glass (only light transmitting / shading), the light utilization rate is increased by more than 30%; strong material compatibility: key materials such as substrates, electrodes, liquid crystals, etc. can be replaced with a variety of mature industrial materials, reducing the cost of large-scale production.

[0019] In summary, this composite grating structure electroluminescent film achieves multi-dimensional regulation from basic shading to precise light diffraction through layered design and multi-level control, and has significant application value in the fields of smart glass, display devices, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0021] Figure 1 It is a structural schematic diagram of a composite grating structure electroluminescent film of the present invention. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] As shown in the figure, the embodiment of the present invention includes: a composite grating structure electroluminescent film, the specific structure, working principle and advantages of which are described as follows:

[0024] The composite grating structure electroluminescent film of this embodiment adopts a layered stacking design, which includes, from bottom to top, a lower substrate 1, a planar dimming layer, a grating dimming layer, and an upper substrate 18. The specific structure of each layer is as follows:

[0025] The lower substrate 1 and the upper substrate 18 are the supporting bases of the film. In this embodiment, deformable ultra-thin glass material (thickness of about 50μm) is selected, which has both rigid support and flexible bending ability (bending radius ≤ 10mm); it can also be replaced with organic PET or TPU material (thickness 50-200μm) according to the application scenario, which is suitable for curved glass or foldable devices; the upper and lower substrate materials can be the same or different to balance cost and performance requirements.

[0026] The planar dimming layer is located between the lower substrate 1 and the grating dimming layer, and is composed of a lower planar transparent electrode 4, a dye liquid crystal 5, and an upper planar transparent electrode 6. The lower planar transparent electrode 4 and the upper planar transparent electrode 6 are made of ITO material with a transmittance of ≥85% and a surface resistance of ≤10 ; It can also be replaced with conductive polymer PEDOT to improve the conductive stability during flexible bending.

[0027] Dye liquid crystal 5 is filled between the two electrodes. DPL material is selected, and the layer thickness is controlled to be 50μm. Its molecular arrangement can be controlled by the voltage applied by the electrode (0-5V): when not powered on, the liquid crystal molecules are arranged disorderly and absorb visible light (transmittance ≤ 10%); after power is applied, the molecules are arranged in an orderly manner along the direction of the electric field and do not absorb light (transmittance ≥ 80%).

[0028] A PDMS flexible filler 2 (20 μm thick) is filled between the lower substrate 1 and the planar dimming layer, and a transparent lower spacer 3 (made of SiO2 microspheres, 20 μm in diameter) is provided to uniformly support the planar dimming layer and avoid uneven thickness of the liquid crystal layer due to substrate deformation.

[0029] The grating dimming layer is located between the planar dimming layer and the upper substrate 18 and includes at least two levels of grating structures. This embodiment adopts a dual-level structure of a primary grating 9 and a secondary grating 10. The specific composition is as follows:

[0030] Each level of the grating structure consists of a grating lower electrode 8, a first-level grating liquid crystal 11, a second-level grating liquid crystal 12, a first-level grating upper electrode 15 and a second-level grating upper electrode 17; the grating lower electrode 8 and the second-level grating upper electrode 17 are both made of zinc oxide transparent conductive material (thickness 80nm) with a transmittance ≥88%; the first-level grating liquid crystal 11 and the second-level grating liquid crystal 12 are made of nematic phase liquid crystal (response time ≤10ms) and filled in the grating grooves.

[0031] The grating structure is a sawtooth vertical grating (groove depth 5μm, period 10μm), which can also be replaced by a sawtooth or tilted grating (tilt angle 30°) to adjust the diffraction angle; the first-order grating 9 and the second-order grating 10 are insulated and isolated by a grating layer spacer 13 (made of SiN, thickness 5μm) to avoid crosstalk between electrodes; PMMA grating layer flexible filler 14 (thickness 10μm) is filled between the grating structures to enhance structural stability.

[0032] Isolation layers are set between adjacent electrodes: the lower electrode isolation layer 7 (made of UTG, with a thickness of 3μm) is located between the planar transparent electrode 6 on the planar dimming layer and the grating lower electrode 8; the grating upper electrode isolation layer 16 (made of ultra-thin sapphire, with a thickness of 2μm) is located between the secondary grating upper electrode 17 and the upper substrate 18 to ensure independent control of each electrode.

[0033] The planar dimming layer applies voltage through the lower planar transparent electrode 4 and the upper planar transparent electrode 6, which can independently control the transmittance state of the dye liquid crystal 5; when the transparent mode is required (such as lighting inside the car during the day), a 5V voltage is applied to arrange the liquid crystal molecules in an orderly manner, and the transmittance is increased to more than 80%; when the shading mode is required (such as privacy protection at night), the voltage is turned off to disorder the liquid crystal molecules and the transmittance drops to less than 10%.

[0034] The dimming capability is independent of the grating layer, meeting basic light transmission / shading requirements and broadening the application scenarios of the film (such as architectural glass and car side windows).

[0035] The first-stage grating 9 and the second-stage grating 10 of the grating dimming layer are controlled by independent grating lower electrodes 8, first-stage grating upper electrodes 15 and second-stage grating upper electrodes 17; single-stage power-on mode (e.g., only the first-stage grating 9 is powered): the first-stage grating liquid crystal 11 molecules are arranged along the grating groove direction to form a periodic refractive index distribution, producing first-stage diffraction (diffraction angle θ = arcsin (λ / period), λ is the wavelength of light) of the incident light (e.g., sunlight), dispersing the strong light into a soft light beam; multi-stage power-on mode (the first-stage grating 9 and the second-stage grating 10 are powered at the same time): the periods of the two-stage gratings are 10μm and 5μm respectively, forming a composite diffraction system, which can generate multi-stage diffraction beams (e.g., ±1st order, ±2nd order), further optimizing the uniformity of light distribution; off mode (all gratings are powered off): the grating liquid crystal molecules are arranged disorderly, the grating structure has no diffraction effect on light, and only serves as an ordinary light-transmitting layer.

[0036] Independent control of the multi-stage grating enables flexible switching of diffraction modes, allowing the light intensity distribution to be adjusted as needed (e.g., anti-glare for car windshields, uniform lighting for cinema screens).

[0037] The combination of the flexible filler 2 and the grating layer flexible filler 14 with the deformable substrate makes the film bendable (bending radius ≤ 10mm), which is suitable for curved glass (such as curved car side windows and folding mobile phone screens); the insulating design of the lower electrode isolation layer 7, the grating layer isolation layer 13 and the grating upper electrode isolation layer 16 avoids current crosstalk between the electrodes, ensuring that each dimming layer works independently; the uniform support of the transparent lower spacer 3 (SiO2 microspheres) prevents uneven thickness of the liquid crystal layer due to external force squeezing (deviation ≤ 5%), thereby improving dimming consistency.

[0038] This film achieves multi-dimensional dimming through the synergy of the planar dimming layer and the grating dimming layer:

[0039] When the planar dimming layer is transparent (the dye liquid crystal 5 is powered on) and the grating layer turns on single-order diffraction, the incident strong light can be dispersed into a soft beam (such as the anti-glare function of the car's side windows); when the planar dimming layer is shading (the dye liquid crystal 5 is powered off) and the grating layer is closed, the entire film is opaque (such as the privacy glass mode); when the planar dimming layer is transparent and the grating layer diffracts multiple levels, uniform lighting can be achieved (such as the diffuse reflection mode of a cinema screen).

[0040] The advantages of this technical solution are:

[0041] Multi-mode dimming capability: Independent / coordinated control of the planar layer and the grating layer, covering multiple modes such as transparency, shading, single-order diffraction, and multi-order diffraction, suitable for a wide range of scenarios;

[0042] High flexibility and stability: The design of the deformable substrate and flexible filler supports curved surface installation and bending; the structural optimization of the isolation layer and spacers ensures dimming consistency during long-term use;

[0043] Highly efficient light control: The diffraction function of the grating structure can accurately adjust the light intensity distribution, compared with traditional single-layer dimming glass (only light transmission / light blocking), the light utilization rate is increased by more than 30%;

[0044] Strong material compatibility: key materials such as substrates, electrodes, and liquid crystals can be replaced with a variety of mature industrial materials, reducing the cost of large-scale production.

[0045] In summary, this composite grating structure electroluminescent film achieves multi-dimensional regulation from basic shading to precise light diffraction through layered design and multi-level control, and has significant application value in the fields of smart glass, display devices, etc.

[0046] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A composite grating structure electroluminescent film, characterized by: The invention comprises a lower substrate (1), a planar dimming layer, a grating dimming layer and an upper substrate (18) which are arranged in sequence from bottom to top; the planar dimming layer comprises a lower planar transparent electrode (4), a dye liquid crystal (5) and an upper planar transparent electrode (6); a flexible filler (2) is provided between the lower substrate (1) and the planar dimming layer; a transparent lower spacer (3) is provided between the lower substrate (1) and the upper planar transparent electrode (6); the transparent lower spacer (3) is used to uniformly support the planar dimming layer; the grating dimming layer comprises at least two levels of grating structures, each level of the grating structure is provided with an independently controlled grating lower electrode (8), a grating liquid crystal and a grating upper electrode, an isolation layer is provided between adjacent electrodes, and a grating layer flexible filler (14) is filled between the grating structures.

2. The composite grating structure electroluminescent film according to claim 1, characterized in that: The grating structure comprises a primary grating (9) and a secondary grating (10).

3. The composite grating structure electroluminescent film according to claim 1, characterized in that: The grating liquid crystal comprises a primary grating liquid crystal (11) and a secondary grating liquid crystal (12).

4. The composite grating structure electroluminescent film according to claim 1, characterized in that: The grating upper electrode comprises a primary grating upper electrode (15) and a secondary grating upper electrode (17).

5. The composite grating structure electroluminescent film according to claim 1, characterized in that: The isolation layer comprises a lower electrode isolation layer (7), a grating layer spacer (13) and a grating upper electrode isolation layer (16).

6. The composite grating structure electroluminescent film according to claim 1, characterized in that: The materials of the lower substrate (1) and the upper substrate (18) are ordinary hard glass, deformable ultra-thin glass, organic PET, PI or TPU material, and the upper and lower substrates are made of the same or different materials.

7. The composite grating structure electroluminescent film according to claim 1, characterized in that: The flexible filler (2) is PDMS or PMMA organic material.

8. The composite grating structure electroluminescent film according to claim 1, characterized in that: The dye liquid crystal (5) is a DPL electroluminescent material.

9. The composite grating structure electroluminescent film according to claim 1, characterized in that: The lower plane transparent electrode (4), the upper plane transparent electrode (6), the grating lower electrode (8), the first-level grating upper electrode (15), and the second-level grating upper electrode (17) are all conductive polymer PEDOT, ITO, or zinc oxide transparent electrodes.

10. The composite grating structure electroluminescent film according to claim 1, characterized in that: The thickness of the dye liquid crystal (5) layer of the planar dimming layer is greater than 10 micrometers and less than 1.0 mm.

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