A dimming system and self-powering method thereof

Abstract

The present invention relates to a dimming system and a self-powered method thereof, which realizes the self-powering of a dimming film and belongs to the field of dimming. The dimming system includes an electret generator, a rectifier, a reset switch, a dimming film structure and a voltage management module. The electret generator can convert external mechanical stimulation into electrical energy. The output end of the electret generator is connected to the input end of the rectifier, the output end of the rectifier is connected to the dimming film structure, and the reset switch, the dimming film structure and the voltage management module are connected in parallel with the dimming film structure to obtain a self-powered dimming system that does not require an external power supply. The self-powered dimming film prepared by the present invention does not require an external power supply. It can realize the function of regulating the light transmittance of the dimming film structure by applying external stimulation, and its initial optical state can be switched by rotating the polarizer, which greatly expands the scope of application. Therefore, it can be used in the fields of architecture, automobiles, electronics, etc.

Description

Technical Field

[0001] The present invention relates to the field of intelligent dimming technology, and in particular to a dimming system and a self-powering method thereof. Background Art

[0002] Liquid crystal dimming film is an electronic light control product. In the absence of an electric field, the electrically controlled dimming polymer dispersed liquid crystal film (PDLC) can achieve the good effect of switching between transparent and matte surfaces.

[0003] Because the liquid crystal dimming film is a liquid crystal / polymer hybrid injected between two transparent conductive films, it is opaque in the absence of an electric field. When powered on, the electric field causes the liquid crystals in the film to align, rendering the film transparent. The electric field allows for rapid switching between on-off and off-on states.

[0004] It can be seen that the performance of liquid crystal dimming film is closely related to the power supply, but due to its external voltage source, this greatly limits its application range.

[0005] Related literature (Wang J, Meng C, Wang CT, et al. A fully self-powered, ultra-stable cholesteric smart window triggered by instantaneous mechanical stimulation. Nano Energy, 2021, 85: 105976) reported a method of charging a cholesteric liquid crystal smart window through a triboelectric nanogenerator. This can achieve the effect of the smart window from transparent to foggy, and through the fogging effect, diffuse reflection of the incident light is achieved to achieve concealment. However, due to material and structural limitations, the following problems still exist:

[0006] 1. To produce the fogging effect, the generator needs to charge the smart window multiple times and make the voltage across the dimming film reach 12V;

[0007] 2. The dimming film cannot be restored to its transparent state by turning off the power. It can only be restored to its initial state by applying an additional mechanical load on the surface of the dimming film.

[0008] 3. The initial optical state of the smart window can only be transparent;

[0009] 4. It is impossible to gradually or selectively adjust the light transmittance of the dimming film by adjusting the power supply according to demand. Summary of the Invention

[0010] In view of this, the purpose of the present invention is to overcome the technical problems in the background technology that the existing self-powered liquid crystal dimming film cannot completely achieve light regulation by powering off, requires high voltage to be generated in the dimming film itself, and requires additional load to be added to the dimming film itself, resulting in limited application scope, thereby providing a dimming system and its self-powering method to achieve self-powering of the dimming system and adjustable visible light transmittance.

[0011] To solve the above problems, a first object of the present invention is to provide a dimming system, comprising:

[0012] dimming film structure;

[0013] An electret generator comprising oppositely disposed first substrates, first electrode layers bonded to opposite sides of the first substrates, and a charged electret film connected to a surface of one of the first electrode layers, the charged electret film being located between the two first electrode layers;

[0014] a rectifier circuit having an input end and an output end oppositely disposed, wherein the two input ends are electrically connected to the first electrode layer of the electret generator, and the two output ends are electrically connected to the dimming film structure;

[0015] A reset switch is connected in parallel to the dimming film structure;

[0016] A voltage management module is connected in parallel to the reset switch and is used to store the charge generated by the electret generator and provide overvoltage protection for the dimming film structure; in the absence of external stimulation, the voltage management module supplies power to the dimming film structure and maintains the voltage across the dimming film structure.

[0017] Optionally, the dimming film structure includes a dimming film, a transparent substrate clamped between the upper and lower surfaces of the dimming film, a second electrode layer attached to the transparent substrate and located on a side close to the dimming film, and a polarizer adhered to the transparent substrate and located on a side away from the dimming film. The output ends relatively arranged in the rectifier circuit are respectively electrically connected to the second electrode layer of the dimming film structure.

[0018] Optionally, the voltage management module includes an external capacitor and a voltage stabilizing diode connected in parallel, and the external capacitor and the voltage stabilizing diode are connected in parallel on the second electrode layer;

[0019] When there is continuous external stimulation, the voltage stabilizing diode is used to release excess charge between the second electrode layers to prevent excessive voltage at both ends of the dimming film structure from damaging the liquid crystal structure of the dimming film.

[0020] Optionally, the restoration switch includes two substrates with third electrode layers, the third electrode layers are printed on opposite surfaces of the substrates, and the third electrode layers are respectively connected to the output ends of the rectifier circuit.

[0021] Optionally, the materials of the light-transmitting substrate and the second electrode layer are a transparent base and a transparent electrode, respectively.

[0022] Optionally, the electret material of the charged electret film is any one of polyvinylidene fluoride, perfluoroethylene propylene copolymer, polyimide, polychlorotrifluoroethylene, polypropylene, polyethylene, cycloolefin copolymer, soluble polytetrafluoroethylene, polyvinyl fluoride and parylene.

[0023] A second object of the present invention is to provide a self-powering method for a dimming system. Based on the dimming system described above, the self-powering method includes the following steps:

[0024] S 100 : Prepare the electret generator, rectifier circuit, restoration switch, dimming film structure and voltage management module respectively;

[0025] S 200 : electrically connecting the electret generator to the reset switch, the dimming film structure and the voltage management module through the rectifier circuit;

[0026] S 300 : Rotate the relative angle of the two polarizers to select the initial light transmittance of the dimming film;

[0027] S 400 : Adjusting the light transmission state of the dimming film, the light transmission state of the dimming film includes a first switching mode and a second switching mode, wherein:

[0028] The first switching mode is that the dimming film changes from a light-transmitting state to a dark state;

[0029] The second switching mode is when the dimming film changes from a dark state to a light-transmitting state.

[0030] Optionally, in step S 400 In the embodiment, the operation steps of the first switching mode include:

[0031] The dimming film is initially in a light-transmitting state;

[0032] When the electret generator is pressed, the electret generator injects charges into the second electrode layer of the dimming film structure, forming a voltage on both sides of the dimming film. The stable voltage between the second electrode layers causes the liquid crystal molecules of the dimming film to deflect, and the dimming film becomes darker.

[0033] When the reset switch is pressed, the dimming film returns to the light-transmitting state.

[0034] Optionally, in step S 400 , the operation steps of the second switching mode include:

[0035] Adjusting the polarization direction between the two polarizers to 45 degrees to make the dimming film in a translucent state;

[0036] When the electret generator is pressed, the dimming film changes to a transparent state; when the reset switch is pressed, the dimming film returns to a dark state.

[0037] Optionally, the charging method of the electret material of the electret generator includes corona charging, friction charging, contact polarization, liquid polarization and high temperature polarization.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The present invention uses an electret generator to induce varying amounts of positive charge between the upper and lower electrodes of the first electrode layer. Changing the distance between the electret and the upper and lower electrodes changes the potential difference between the two electrodes, inducing electron flow between the upper and lower electrodes. By connecting a rectifier circuit, this electron flow between the first electrode layers can be converted into DC pulses. By connecting the rectifier circuit to the dimming film structure, the capacitor structure formed by the dimming film and the second electrode layer is charged. The backflow effect of the rectifier circuit maintains a stable charge on both sides of the second electrode layer of the dimming film structure, forming a stable voltage, which deflects the liquid crystal molecules, dimming the dimming film, and thus achieving the dimming function.

[0040] 2. Compared with the existing technology, to produce such an effect, the generator needs to charge the dimming film for multiple cycles, and the voltage at both ends of the dimming film needs to reach 12V. It also solves the problem that the existing technology cannot restore the dimming film to a transparent state by cutting off the power, further broadening the application scope of the dimming film; and completely solves the limitation of the existing technology that the initial optical state of the dimming film can only be a transparent state. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the structure of the dimming system in an embodiment of the present invention;

[0042] Figure 2 A schematic structural diagram of a dimming film structure according to an embodiment of the present invention;

[0043] Figure 3 Schematic diagram of the transmittance adjustment principle of the dimming film structure in an embodiment of the present invention;

[0044] Figure 4Schematic diagram of the light transmission state of the dimming system in different triggering modes in an embodiment of the present invention, in which the initial state is transparent;

[0045] Figure 5 Schematic diagram of the light transmittance state of the dimming system in different triggering modes in an embodiment of the present invention, in which the initial state is the dark state;

[0046] Figure 6 Schematic diagram of visible light transmittance of a dimming system in different modes with an initial transparent state according to an embodiment of the present invention;

[0047] Figure 7 Schematic diagram of the output performance of the electret generator in the first embodiment of the present invention;

[0048] Figure 8 This is a schematic diagram of the output performance of the electret generator according to the second embodiment of the present invention;

[0049] Figure 9 Schematic diagram showing the relationship between the voltage and transmittance of the dimming film according to the number of times the electret generator is pressed in an embodiment of the present invention;

[0050] Figure 10 Schematic diagram of the relationship between the voltage change of different external capacitors and the dimming film in an embodiment of the present invention;

[0051] Figure 11 Schematic diagram of the self-powering method of the dimming system in an embodiment of the present invention.

[0052] Description of reference numerals:

[0053] 1- Electret generator;

[0054] 11-charged electret film; 12-first electrode layer; 13-first substrate;

[0055] 2-rectifier circuit;

[0056] 3-Reset switch;

[0057] 31-substrate; 32-third electrode layer;

[0058] 4- dimming film structure;

[0059] 41-transparent substrate; 42-second electrode layer; 43-dimming film; 44-polarizer;

[0060] 5- Voltage management module;

[0061] 51-external capacitor, 52-Zener diode. DETAILED DESCRIPTION

[0062] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0063] In the description of the present invention, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely for distinction and should not be construed as indicating or implying relative importance.

[0064] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0065] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0066] like Figure 1-10 As shown, an embodiment of the present invention provides a dimming system, which includes an electret generator 1, a rectifier circuit 2, a reset switch 3, a dimming film structure 4, and a voltage management module 5, wherein:

[0067] The electret generator 1 includes a first substrate 13, a first electrode layer 12 and a charged electret film 11 arranged opposite to each other. The first electrode layer 12 is bonded to the opposite side of the first substrate 13, and the charged electret film 11 is connected to the surface of one of the first electrode layers 12, and the charged electret film 11 is located between the two first electrode layers 12.

[0068] In this embodiment, the charged electret film 11 is connected to the lower surface of the first electrode layer 12. At this time, any dielectric material can be filled between the charged electret film 11 and the lower electrode of the first electrode layer 12 to suppress breakdown and improve output performance.

[0069] As a preferred implementation of the embodiment of the present invention, the electret generator 1 in this embodiment is an energy conversion device, which can also be a friction generator, a thermoelectric generator, and a dielectric elastomer generator, etc. Any device that can convert the surrounding environment stimulation into electrical energy can be used to replace the electret generator 1 in the embodiment of the present invention to meet the needs of different application environments.

[0070] The rectifier circuit 2 has an input terminal and an output terminal arranged opposite to each other. The two input terminals are respectively electrically connected to the first electrode layer 12 of the electret generator 1, and the two output terminals are respectively electrically connected to the second electrode layer 42 of the dimming film structure 4. Furthermore, the rectifier circuit 2 in this embodiment can also be replaced with any electronic device with a unidirectional conduction function, such as a diode.

[0071] The reset switch 3 is connected in parallel to the dimming film structure 4 .

[0072] The voltage management module 5 is connected in parallel to the reset switch 3. The voltage management module 5 is used to store the charge generated by the electret generator 1 and provide overvoltage protection. When there is no external stimulation, the voltage management module 5 supplies power to the dimming film structure 4 and maintains the voltage across the dimming film structure 4. When there is continuous external stimulation, the voltage management module 5 releases excess charge to prevent the liquid crystal material of the dimming film structure 4 from being damaged by high voltage.

[0073] In the embodiment of the present invention, in order to prepare the electret generator 1, the specific implementation process is as follows:

[0074] First, a first electrode layer 12 is prepared on one side of the charged electret film 11, and then the electret is subjected to negative corona polarization by a -10kV high voltage source. Preferably, the area of ​​the electret used here is 5cm 2 , thickness is 50μm.

[0075] Next, the surface of the charged electret film 11 having the first electrode layer 12 is fixed on the first substrate 13 .

[0076] As the best preferred embodiment of this invention, the material used for the first substrate 13 is polyethylene terephthalate (PET) and is fixed by using a conventional adhesive.

[0077] Finally, the charged electret film 11 and the first substrate 13 with the first electrode layer 12 are combined to form the electromechanical conversion device in this embodiment.

[0078] In the embodiment of the present invention, the electret material in the electret generator 1 includes but is not limited to polyvinylidene fluoride (PVDF), perfluoroethylene propylene copolymer (FEP), polyimide (PI), polychlorotrifluoroethylene (PCTFE), polypropylene (PP), polyethylene (PE), cycloolefin copolymer (COC), soluble polytetrafluoroethylene (PFA), polyvinyl fluoride (E-TFE), Parylene and other electret materials.

[0079] In the embodiment of the present invention, the charging method of the electret material of the electret generator 1 includes corona charging, friction charging, contact polarization, liquid polarization and high temperature polarization.

[0080] It should be explained in detail here that, for those skilled in the art, electret material is a material that can be semi-permanently charged, which is common knowledge.

[0081] See also Figure 2 As shown, in the embodiment of the present invention, the dimming film structure 4 includes a transparent substrate 41, a second electrode layer 42, a dimming film 43 and a polarizer 44, wherein:

[0082] The transparent substrate 41 is clamped between the upper and lower surfaces of the dimming film 43, the second electrode layer 42 is printed on the transparent substrate 41 and is located on the side close to the dimming film 43, the polarizer 44 is adhered to the transparent substrate 41 and is located on the side away from the dimming film 43, and the output ends relatively arranged in the rectifier circuit 2 are electrically connected to the second electrode layer 42 of the dimming film structure 4 respectively.

[0083] In addition, the dimming film 43 in this embodiment is a liquid crystal dimming layer. The liquid crystal of the dimming film 43 can be TN type liquid crystal or STN type. Of course, a mixture of the two liquid crystals or a small amount of cholesteric liquid crystal can also be used. Specifically, in the embodiment of the present invention, TN liquid crystal is preferably used. TN liquid crystal is a twisted nematic liquid crystal material with a twist angle of 90-110° and has optical activity.

[0084] It's worth explaining that when TN liquid crystal is used as the liquid crystal layer material, polarizing layers are placed on either side of the conductive layer. Incident light passes through the outer polarizing layer to form polarized light. This polarized light is then rotated by the twisted liquid crystals as it passes through the liquid crystal layer. When the absorption axes of the two polarizing layers are perpendicular to each other, the rotated polarized light can pass smoothly through the inner polarizing layer, resulting in a higher transmittance for the heat-insulating, sun-blocking, and light-variable liquid crystal film. When an electric field is applied to the liquid crystal layer, the liquid crystal molecules shift from a twisted state to an untwisted state, maintaining the polarization direction of the polarizing layer formed on the outer side. Therefore, the light cannot fully pass through the inner polarizing layer, resulting in a lower transmittance for the heat-insulating, sun-blocking, and light-variable liquid crystal film.

[0085] In addition, the horizontal relative angle between the upper and lower polarizers 44 can be manually adjusted to adjust the desired light transmittance variation range of the dimming film 43 .

[0086] In the embodiment of the present invention, the specific implementation process for preparing the dimming film structure 4 is as follows:

[0087] First, a transparent second electrode layer 42 is prepared on two transparent substrates 41. The materials used for the transparent substrates 41 and the second electrode layer 42 are transparent glass and indium tin oxide (ITO), respectively.

[0088] Specifically in this embodiment, the materials of the transparent substrate 41 and the second electrode layer 42 are a transparent substrate and a transparent electrode, respectively. The transparent substrate is preferably transparent glass, and the transparent electrode is preferably any one of fluorine-doped tin oxide, indium tin oxide, and metal nanowires, more preferably indium tin oxide.

[0089] It should be noted that the indium tin oxide (ITO) used in this embodiment is sputtered on transparent glass by magnetron sputtering, and its visible light transmittance is greater than 60% and its square resistance is less than 600 ohms / square, which is a conventional technical means for those skilled in the art.

[0090] Next, the dimming film 43 is placed between the two second electrode layers 42 , and a polarizer 44 is attached to the outermost layers of each of the two transparent substrates 41 . The two polarizers 44 are arranged parallel to each other.

[0091] Finally, by rotating the horizontal relative angle between the two polarizers 44, the initial light transmittance of the dimming film 43 is screened. It should be noted that when the polarization directions of the two polarizers 44 are approximately 90 degrees, the dimming film 43 is in a light-transmitting state.

[0092] See also Figure 1 As shown, specifically in the embodiment of the present invention, the dimming film 43 is composed of TN type liquid crystal material. Of course, any liquid crystal material that responds to an electric field, or a liquid crystal mixture can also be selected.

[0093] This dimming film 43 has a structure using liquid crystal. In this dimming film 43 using liquid crystal, a liquid crystal cell is made by sandwiching a liquid crystal material between transparent film materials with transparent electrodes, and the liquid crystal cell is sandwiched between polarizing plates 44.

[0094] Thus, in the dimming film 43, by varying the electric field applied to the liquid crystals, the liquid crystal orientation is altered, thereby blocking or transmitting external light, thereby varying the amount of transmitted light and controlling the transmission of external light. Thus, by adjusting the horizontal relative angle between the two polarizers 44, the desired range of light transmittance variation of the dimming film 43 can be achieved.

[0095] Preferably, in this embodiment, the area of ​​the dimming film 43 is 10×10 cm 2 .

[0096] In addition, it can be understood that the full name of the polarizer 44 is polarizer, which is a multi-layer structure film material that can convert non-polarized light into polarized light and is a conventional material in this technical field.

[0097] See also Figure 1 As shown, in an embodiment of the present invention, the reset switch 3 includes two substrates 31 with third electrode layers 32 , the third electrode layers 32 are printed on opposite side surfaces of the substrates 31 , and the third electrode layers 32 are respectively connected to the output ends of the rectifier circuit 2 .

[0098] Specifically, the reset switch 3 is a piezoresistive switch structure that controls the conduction of the third electrode layer 32. Specifically in this embodiment, the reset switch 3 is composed of two substrates 31 with the third electrode layer 32. By pressing the reset switch 3, the second electrode layer 42 of the dimming film structure 4 can be turned on, thereby restoring the dimming film 4 to its original state.

[0099] See also Figure 1 As shown, in this embodiment, the electret generator 1 can be connected to the reset switch 3 and the dimming film structure 4 via a rectifier circuit 2. The rectifier circuit 2 is used to rectify the mains power into a first DC output. The rectifier circuit 2 can be a rectifier bridge, a rectifier diode, or other components with a rectifier function.

[0100] As an optional embodiment, the rectifier circuit 2 is a bridge rectifier circuit, such as Figure 1 As shown, due to its specific connection method, it is a routine experimental operation in this technical field and will not be described here.

[0101] According to the principle of electrostatic induction, since the electret material in the electret generator 1 is negatively charged, different amounts of positive charges will be induced on the upper and lower electrodes in the first electrode layer 12. When the distance between the electret and the lower electrode is changed, the potential difference between the upper and lower electrodes in the first electrode layer 12 changes, and electrons flow between the upper and lower electrodes.

[0102] See also Figure 1As shown, by connecting the rectifier bridge of the rectifier circuit 2, this electron flow can be converted into DC pulses, and then the rectifier bridge of the rectifier circuit 2 is connected to the dimming film structure 4. Under the action of the electret generator 1, the second electrode layer 42 on the dimming film structure 4 can be charged. Due to the backflow effect of the rectifier bridge, the charge can be maintained stably on the electrodes on both sides of the dimming film structure 4, forming a stable voltage, deflecting the liquid crystal molecules, dimming the dimming film 4, and thus achieving the dimming function.

[0103] See also Figure 1 As shown, in this embodiment of the present invention, the voltage management module 5 includes an external capacitor 51 and a Zener diode 52 connected in parallel. The external capacitor 51 and the Zener diode 52 are connected in parallel to the second electrode layer 42. The function of the external capacitor 51 is to store the charge generated by the electret generator 11. In the absence of external stimulation, it provides power to the dimming film structure 4 to maintain the voltage across the dimming film 4 and ensure optical stability. The function of the Zener diode 52 is to release excess charge from the upper and lower electrode layers of the dimming film 4 to prevent the voltage from exceeding the threshold and causing damage to the liquid crystal molecules.

[0104] Therefore, when there is continuous external stimulation, the voltage-stabilizing diode 52 is used to release the excess charge between the second electrode layer 42 to prevent the excessively high voltage across the dimming film structure 4 from damaging the liquid crystal structure of the dimming film 43 .

[0105] As a preferred implementation of an embodiment of the present invention, the first electrode layer 12 and the third electrode layer 32 are made of the same material, which is a conductive material with a certain optical transmittance. The manufacturing materials include but are not limited to copper, gold, aluminum, silver and its nanowires, carbon tubes and other electrode materials.

[0106] See also Figure 11 As shown, another embodiment of the present invention further provides a self-powering method for a dimming system. Based on the dimming system described above, the self-powering method includes the following steps:

[0107] S 100 : Prepare the electret generator 1, the rectifier circuit 2, the reset switch 3, the dimming film structure 4 and the voltage management module 5 respectively;

[0108] S 200 : The electret generator 1 is electrically connected to the reset switch 3, the dimming film structure 4 and the voltage management module 5 through the rectifier circuit 2;

[0109] S 300 : Rotate the horizontal relative angle of the two polarizers 44 to select the initial light transmittance of the dimming film 43;

[0110] S 400: Adjust the light transmission state of the dimming film 43, the light transmission state of the dimming film 43 includes a first switching mode and a second switching mode, wherein:

[0111] The first switching mode is when the dimming film 43 changes from a light-transmitting state to a dark state;

[0112] The second switching mode is when the dimming film 43 changes from a dark state to a light-transmitting state.

[0113] Specifically in the embodiment of the present invention, in step S 400 In the embodiment, the operation steps of the first switching mode include:

[0114] The dimming film structure 4 is initially in a light-transmitting state;

[0115] When the electret generator 1 is pressed, the electret generator 1 is suitable for charging the second electrode layer 42 of the dimming film structure 4, and the dimming film structure 4 gradually darkens; the stable voltage between the second electrode layers 42 causes the liquid crystal molecules of the dimming film 43 to deflect, and the visible light transmittance of the dimming film structure 4 decreases, that is, it darkens; when the restoration switch 3 is pressed, the dimming film structure 4 returns to the light-transmitting state.

[0116] Specifically in the embodiment of the present invention, in step S 400 , the operation steps of the second switching mode include:

[0117] Adjust the polarization direction between the two polarizers 44 to 45 degrees to make the dimming film 43 in a semi-transparent state;

[0118] When the electret generator 1 is pressed, the dimming film structure 4 changes to a transparent state; when the reset switch 3 is pressed, the dimming film structure 4 returns to a dark state.

[0119] First embodiment:

[0120] In the first embodiment of the present invention, the dimming system also includes an electret generator 1, a rectifier circuit 2, a reset switch 3, a dimming film structure 4, and a voltage management module 5. The difference is that the electret film 11 used in the electret generator 1 is a perfluoroethylene propylene copolymer (FEP) with an area of ​​5 cm 2 , thickness is 12.5μm; the film area of ​​the selected dimming film 43 is 10×10cm 2 , the capacitance is 92nF; the size of the external capacitor 51 selected is 10nF; the type of the voltage regulator diode 52 selected is 1N739, and the voltage regulation value is 9.1V.

[0121] When the electret generator 1 is pressed, the horizontal relative angle of the two polarizers 44 is about 90 degrees, that is, the initial state of the dimming film 43 is as follows. Figure 4 shown.

[0122] according to Figure 4 In the operation mode shown, the dimming film structure 4 changes from a visible light transmitting state to an opaque state, and can obtain Figure 6 The light transmittance of the dimming film 43 varies with wavelength.

[0123] See also Figure 7 As shown, when the electret generator 1 is pressed, a potential difference exists between the upper and lower electrodes in the first electrode layer 12 of the electret generator 1. When the electret generator 1 is fully pressed and released under an external force of 10N, the open-circuit voltage generated by the electret generator 1 is 280V, and the unidirectional charge transfer is 180nC. Through the rectifier bridge of the rectifier circuit 2, the charge is charged into the upper and lower electrodes in the second electrode layer 42 of the dimming film 43 and the external capacitor 51, resulting in a voltage of 3.1V across the dimming film.

[0124] Second embodiment:

[0125] Figure 8 The voltage output characteristic and charge output characteristic of the electret generator 1 are shown in the figure. Compared with the first embodiment, the difference is that the electret film 11 used in the electret generator 1 is made of polytetrafluoroethylene (PTFE) with an area of ​​5 cm 2 , thickness is 50 μm. Other parameters are the same as those in the first embodiment.

[0126] according to Figure 5 In the operating mode shown, the dimming film 43 is placed between the two second electrode layers 42, and a polarizer 44 is attached to the outermost layer of each of the two second electrode layers 42. By rotating the horizontal relative angle between the two polarizers 44, the initial light transmittance is screened. At this time, the polarization direction of the two polarizers 44 is 45 degrees, and the dimming film is in a translucent state; when the electret generator 1 is pressed, the dimming film 4 becomes transparent, and when the reset switch 3 is pressed, the dimming film returns to the translucent state.

[0127] See also Figure 8 As shown, under the action of an external force of 10 N, when the electret generator 1 is fully pressed and released, the open circuit voltage generated by the electret generator 1 is 60 V, and the unidirectional transferred charge is 70 nC.

[0128] The charge in the rectifier circuit 2 is charged between the upper and lower second electrode layers 42 of the dimming film 43 and into the external capacitor 51, and the voltage across the dimming film 43 is 1.2V.

[0129] The electret generator 1 is continuously pressed, and the voltage across the dimming film 43 continues to rise. Due to the voltage stabilization effect of the voltage stabilizing diode 52, the voltage reaches the saturation voltage of 9.1V and cannot be increased further.

[0130] See also Figure 9 As shown, as the voltage increases, the transmittance of the dimming film 443 at a wavelength of 500nm decreases. By adjusting the electret generator 1, the visible light transmittance of the dimming film 43 can be adjusted. The visible light transmittance can be adjusted by adjusting the pressing force, the size of the electret generator 1, the number of electret generators 1 stacked, and the material.

[0131] Third embodiment:

[0132] The embodiment conditions in the third embodiment are the same as those in the first embodiment, and the only difference is the size of the external capacitor 51. The type of the external capacitor 51 is a CBB capacitor.

[0133] See also Figure 10 As shown, the voltage of the dimming system connected to different external capacitors 51 is increased to 4 V. As time goes by, the voltage across the dimming film 43 slowly decreases, but the voltage of the dimming film 43 connected to the external capacitor 51 decreases more slowly.

[0134] Compared to the dimming film 43, the external capacitor 51 has excellent charge retention below 9.1V. When the voltage of the dimming film 43 drops, the external capacitor 51 provides charge to maintain the voltage of the dimming film 43. As the capacitance of the external capacitor 51 increases, the voltage across the dimming film 43 drops more slowly, ensuring a low visible light transmittance for a long time.

[0135] Fourth embodiment:

[0136] The implementation conditions in the fourth embodiment 4 are the same as those in the first embodiment, with the two polarizers 44 being orthogonal. In this embodiment, when one of the polarizers 44 is rotated counterclockwise by approximately 45°, the polarization directions of the two polarizers are approximately 45° apart, and the initial optical state of the dimming film structure 4 is translucent.

[0137] See also Figure 11 As shown, when the electret generator 1 is pressed, the dimming film structure 4 changes from translucent to transparent. Further rotating one of the polarizers 44 to the left by 90 degrees gradually changes the initial optical state of the dimming film structure 4 to yellow. Pressing the electret generator 1 also changes the dimming film structure 4 from yellow to transparent.

[0138] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A dimming system, characterized in that: include: A dimming film structure (4), the dimming film structure (4) comprising a dimming film (43), a transparent substrate (41) sandwiched between the upper and lower surfaces of the dimming film (43), a second electrode layer (42) attached to the transparent substrate (41) and located on a side close to the dimming film (43), and a polarizer (44) attached to the transparent substrate (41) and located on a side away from the dimming film (43); the materials of the transparent substrate (41) and the second electrode layer (42) are a transparent base and a transparent electrode, respectively; An electret generator (1) comprising first substrates (13) arranged opposite to each other, first electrode layers (12) bonded to opposite sides of the first substrates (13), and a charged electret film (11) connected to the surface of one of the first electrode layers (12), wherein the charged electret film (11) is located between the two first electrode layers (12); A rectifier circuit (2) having an input terminal and an output terminal that are arranged opposite to each other, the two input terminals being electrically connected to the first electrode layer (12) of the electret generator (1), the two output terminals being electrically connected to the dimming film structure (4), and the output terminals that are arranged opposite to each other in the rectifier circuit (2) being electrically connected to the second electrode layer (42) of the dimming film structure (4); A reset switch (3) is connected in parallel to the dimming film structure (4); A voltage management module (5) is connected in parallel to the reset switch (3) and is used to store the charge generated by the electret generator (1) and provide overvoltage protection for the dimming film structure (4); when there is no external stimulation, the voltage management module (5) supplies power to the dimming film structure (4) and maintains the voltage across the dimming film structure (4); The voltage management module (5) comprises an external capacitor (51) and a voltage stabilizing diode (52) connected in parallel, wherein the external capacitor (51) and the voltage stabilizing diode (52) are connected in parallel on the second electrode layer (42); the external capacitor (51) is a CBB capacitor; When there is continuous external stimulation, the voltage-stabilizing diode (52) is used to release excess charge between the second electrode layer (42) to prevent excessive voltage at both ends of the dimming film structure (4) from damaging the liquid crystal structure of the dimming film (43).

2. The dimming system according to claim 1, wherein: The reset switch (3) comprises two substrates (31) with third electrode layers (32), wherein the third electrode layers (32) are printed on opposite surfaces of the substrates (31), and the third electrode layers (32) are respectively connected to the output ends of the rectifier circuit (2).

3. The dimming system according to claim 1, wherein: The electret material of the charged electret film (11) is any one of polytetrafluoroethylene, perfluoroethylene propylene copolymer, polyimide, polychlorotrifluoroethylene, polypropylene, polyethylene, cycloolefin copolymer, soluble polytetrafluoroethylene, polyvinyl fluoride and parylene.

4. A self-powered method for a dimming system, based on the dimming system according to any one of claims 1 to 3, characterized in that: The self-powered method comprises the following steps: S 100 : preparing an electret generator (1), a rectifier circuit (2), a reset switch (3), a dimming film structure (4) and a voltage management module (5) respectively; S 200 : electrically connecting the electret generator (1) to the reset switch (3), the dimming film structure (4) and the voltage management module (5) through the rectifier circuit (2); S 300 : Rotating the relative angle of the two polarizers (44) to screen the initial light transmittance of the dimming film (43); S 400 : Adjusting the light transmission state of the dimming film (43), the light transmission state of the dimming film (43) includes a first switching mode and a second switching mode, wherein: The first switching mode is that the dimming film (43) changes from a light-transmitting state to a dark state; The second switching mode is when the dimming film (43) changes from a dark state to a light-transmitting state.

5. The self-powered method for a dimming system according to claim 4, wherein: In step S 400 In the embodiment, the operation steps of the first switching mode include: The dimming film (43) is initially in a light-transmitting state; When the electret generator (1) is pressed, the electret generator (1) injects charge into the second electrode layer (42) of the dimming film structure (4), forming a voltage on both sides of the dimming film (43); the stable voltage between the second electrode layers (42) causes the liquid crystal molecules of the dimming film (43) to deflect, and the dimming film (43) becomes darker; When the reset switch (3) is pressed, the dimming film (43) returns to a light-transmitting state.

6. The self-powered method for a dimming system according to claim 4, wherein: In step S 400 , the operation steps of the second switching mode include: Adjusting the polarization direction between the two polarizers (44) to 45 degrees so that the dimming film (43) is in a translucent state; When the electret generator (1) is pressed, the dimming film (43) changes to a transparent state; when the reset switch (3) is pressed, the dimming film (43) returns to a dark state.

7. The self-powering method of a dimming system according to claim 5 or 6, characterized in that: The charging methods of the electret material of the electret generator (1) include corona charging, friction charging, contact polarization, liquid polarization and high-temperature polarization.

Images