Smart window and manufacturing method therefor

Abstract

A smart window and a manufacturing method for a smart window, which are used for solving the problem of it being impossible to maintain the opaque state of an existing smart window due to the haze value of the smart window decreasing with time. The smart window comprises: two substrates (1) which are opposite each other in parallel, wherein the two substrates (1) are transparent and conductive, and the substrates (1) both have a plurality of protruding particles (11), which are randomly distributed on opposite inner side surfaces of the two substrates (1); a liquid crystal layer (2), which is made of a liquid crystal material filled between the two substrates (1), wherein the liquid crystal material contains negative liquid crystal, a spiral molecule, a salt ion and an ultraviolet curing adhesive; and a pulse generator (3), which is electrically connected to the two substrates (1), wherein the pulse generator (3) alternately outputs a low-frequency pulse voltage and a high-frequency pulse voltage, thereby forming an electric field change between the two substrates (1).

Description

Smart window and manufacturing method thereof Technical Field

[0001] The present invention relates to a photoelectric component technology, and more particularly to a smart window capable of maintaining a high haze value to scatter penetrating light, and a manufacturing method thereof. Background Art

[0002] Existing smart windows use active control methods such as powering on or lighting to enable the windows to switch between transparent and visible states and fogged and blurred states. In the transparent state, light can directly penetrate the window, achieving the functions of lighting and seeing through objects on the other side of the window; in the fogged state, light is scattered when passing through the window, resulting in a blurred image on the other side of the window, achieving a privacy protection effect while retaining the lighting function. Technical issues

[0003] Existing smart windows can be bistable liquid crystal panels. Applying a pulse voltage to the smart window can cause the smart window to switch from a transparent state to a scattering state, or from a scattering state to a transparent state. In the absence of applied voltage, the smart window can maintain the transparent state or the scattering state. However, after the existing smart window switches from the transparent state to the scattering state and the application of voltage is stopped, the haze value of the smart window decreases over time. Therefore, without relying on an external voltage, the existing smart window has difficulty maintaining the hazy state for a long time. The effect of scattering the penetrating light of the smart window will gradually disappear and the window will return to transparency.

[0004] In view of this, existing smart windows still need to be improved. Technical Solutions

[0005] To solve the above problems, an object of the present invention is to provide a smart window that can provide a shielding effect for privacy protection.

[0006] Another object of the present invention is to provide a smart window that can prolong the duration of the fogging state.

[0007] Another object of the present invention is to provide a method for manufacturing a smart window, which can simplify the manufacturing process of the smart window.

[0008] The use of the quantifier "a" or "an" in the elements and components described throughout the present invention is only for convenience and to provide a general meaning of the scope of the present invention; in the present invention, it should be interpreted as including one or at least one, and the concept of a single one also includes the plural case, unless it is obvious that it means otherwise.

[0009] The smart window of the present invention includes: two parallel and opposing substrates, the two substrates are transparent and conductive, each substrate has a plurality of convex particles, and the plurality of convex particles are randomly distributed on the opposing inner surfaces of the two substrates; a liquid crystal layer filled with a liquid crystal material between the two substrates, the liquid crystal material including a negative liquid crystal, a chiral molecule, a salt ion and a UV-curable adhesive; and a pulse generator electrically connected to the two substrates, the pulse generator switchingly outputting a low-frequency pulse voltage and a high-frequency pulse voltage to form an electric field change between the two substrates.

[0010] The smart window manufacturing method of the present invention includes the following steps: filling a liquid crystal material between two substrates to form a liquid crystal layer, the liquid crystal material including negative liquid crystal, chiral molecules, salt ions and a photocurable adhesive; irradiating the liquid crystal layer with ultraviolet light for a certain exposure time so that the photocurable adhesive forms a plurality of convex particles on the inner surfaces of the two substrates; and electrically connecting a pulse generator to each of the two substrates.

[0011] Therefore, the smart window and its manufacturing method of the present invention, by forming the multiple convex particles on the inner surfaces of the two substrates, can enable the liquid crystal layer located between the two substrates to maintain a fogged state in which the liquid crystal molecules are chaotically arranged, so that the liquid crystal layer can avoid gradually returning to a transparent state in which the liquid crystal molecules are neatly arranged when no pulse is applied. In this way, the smart window has the effect of enhancing the shielding effect of privacy protection and prolonging the duration of the fogged state.

[0012] The pulse generator outputs the low-frequency pulse voltage to switch the smart window to a fogged state. This low-frequency pulse voltage causes the liquid crystal molecules in the liquid crystal layer to randomly and chaotically arrange, causing light to scatter when it passes through the liquid crystal layer. Thus, the smart window provides a privacy protection mode.

[0013] The pulse generator outputs the high-frequency pulse voltage to switch the smart window to a transparent state. The high-frequency pulse voltage causes the liquid crystal molecules in the liquid crystal layer to align neatly, allowing light to directly penetrate the liquid crystal layer. Thus, the smart window provides a see-through mode.

[0014] Each substrate includes a transparent conductive material such as indium tin oxide, silver nanowires, conductive graphene, or conductive ink. This increases the proportion of light that penetrates the two substrates, thereby simultaneously enhancing the intensity of both scattered and directly transmitted light. This allows the smart window to increase the amount of light entering both the fogged and transparent states.

[0015] The UV-curable adhesive solidifies after exposure to light to form the multiple convex particles. Thus, the multiple convex particles can be generated by the liquid crystal layer and attached to the inner surfaces of the two substrates without requiring additional precision machining of the two substrates, thus reducing the difficulty of the smart window manufacturing process.

[0016] The low-frequency pulse voltage has a frequency of 60 Hz, and the high-frequency pulse voltage has a frequency of 5000 Hz. The smart window can be switched to a scattering state by a low-frequency pulse and to a transparent state by a high-frequency pulse. Thus, the smart window has the function of switching between see-through and fogging functions.

[0017] The UV light has a wavelength of 357 nanometers and an intensity of 80 milliwatts per square centimeter, and the exposure time is 30 minutes. This allows the photocurable adhesive to absorb sufficient light energy to undergo a polymerization reaction, transforming from a liquid to a solid state. This allows for the rapid and simple formation of the convex particle structure of the smart window. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a side view of a preferred embodiment of the present invention;

[0019] FIG2 is a diagram showing a usage scenario of a preferred embodiment of the present invention;

[0020] FIG3 is a manufacturing flow chart of a preferred embodiment of the present invention;

[0021] FIG4 is a graph comparing the haze values ​​of a preferred embodiment of the present invention and a conventional smart window over time;

[0022] FIG5 is a graph comparing the parallel light transmittance of a preferred embodiment of the present invention and a conventional smart window over time;

[0023] FIG6 is a graph comparing the relationship between applied voltage and haze value for a preferred embodiment of the present invention and a conventional smart window;

[0024] FIG7 : A comparison diagram of the relationship between the applied voltage value and the parallel light transmittance of the preferred embodiment of the present invention and the existing smart window.

[0025] Description of Reference Numerals

[0026] 1: Substrate

[0027] 11: convex particles

[0028] 2: Liquid crystal layer

[0029] 3: Pulse generator

[0030] G: Light-curing adhesive

[0031] UV: ultraviolet light. Best Mode for Carrying Out the Invention

[0032] In order to make the above and other objects, features and advantages of the present invention more obvious and easy to understand, the preferred embodiments of the present invention are listed below and described in detail with reference to the accompanying drawings. In addition, the same symbols in different drawings are regarded as the same and their descriptions are omitted.

[0033] Please refer to Figure 1, which is a preferred embodiment of the smart window of the present invention, including two substrates 1, a liquid crystal layer 2 and a pulse generator 3. The liquid crystal layer 2 is located between the two substrates 1, and the pulse generator 3 is electrically connected to the two substrates 1 respectively.

[0034] The two substrates 1 are arranged parallel to each other with a gap. In this embodiment, the gap is 20 microns. Each substrate 1 has a plurality of convex particles 11 randomly distributed on the inner surfaces of the two substrates 1. The convex particles 11 can restrict the molecular arrangement of the substance between the two substrates 1. In addition, each substrate 1 is preferably a transparent composite material to allow light to pass through the two substrates 1 in both directions. Each substrate 1 can include a sealing material such as glass, acrylic, or plastic to seal the fluid between the two substrates 1. Each substrate 1 can also include a transparent conductive material such as indium tin oxide (ITO), silver nanowires, conductive graphene, or conductive ink. By electrically connecting the two substrates 1 to a power source, a switchable electric field can be formed between the two substrates 1.

[0035] The liquid crystal layer 2 is formed by filling a liquid crystal material between the two substrates 1. In this embodiment, the liquid crystal material includes negative liquid crystal, helical molecules, salt ions and ultraviolet light-curing glue. The ultraviolet light-curing glue is cured to form particles after exposure and is respectively attached to the inner surfaces of the two substrates 1 to form the multiple convex particles 11, which can act on the arrangement of liquid crystal molecules in the liquid crystal material.

[0036] The pulse generator 3 is used to output an AC pulse voltage. The pulse generator 3 can control the AC frequency, voltage amplitude and pulse width (time) of the AC pulse voltage. When the AC pulse voltage acts on the two substrates 1, the electric field between the two substrates 1 changes, which can switch the arrangement of liquid crystal molecules in the liquid crystal layer 2, so that light entering the liquid crystal layer 2 can pass directly or be scattered, thereby switching the smart window to be transparent or fogged.

[0037] As shown in Figure 2, when the pulse generator 3 is not outputting an AC pulse voltage and the liquid crystal molecules in the liquid crystal layer 2 are aligned, light can directly penetrate the liquid crystal layer 2, and the smart window exhibits a stable transparent state. When the pulse generator 3 applies a low-frequency pulse voltage to the smart window, the liquid crystal molecules dynamically and randomly align, causing light to scatter when passing through the liquid crystal layer 2, causing the smart window to switch from a transparent state to a fogged state. When the pulse generator 3 stops applying the low-frequency pulse voltage, the multiple protruding particles 11 on the two substrates 1 prevent the liquid crystal molecules from returning to an aligned state, maintaining their random, chaotic arrangement, and the smart window remains fogged. When the pulse generator 3 applies a high-frequency pulse voltage to the smart window, the liquid crystal molecules align again, restoring the fogged state to a transparent state. After the pulse generator 3 stops applying the high-frequency pulse voltage, the smart window remains transparent. In this embodiment, the low-frequency pulse voltage has a frequency of 60 Hz, and the high-frequency pulse voltage has a frequency of 5000 Hz, but the present invention is not limited to this.

[0038] Please refer to Figure 3, which is a preferred embodiment of the smart window manufacturing method of the present invention, including the following steps: filling the liquid crystal material including negative liquid crystal, helical molecules, salt ions and a photocuring adhesive G between the two substrates 1 to form the liquid crystal layer 2. In this embodiment, the mixture of the negative liquid crystal and the helical ions accounts for 94.5% to 98.9% of the liquid crystal material, and the mixture can make the pitch of the liquid crystal material greater than 700 nanometers or less than 300 nanometers. The salt ions account for 0.1% to 0.5% of the liquid crystal material, and the photocuring adhesive G accounts for 1% to 5% of the liquid crystal material; irradiating the liquid crystal layer 2 with ultraviolet light UV for an exposure time so that the photocuring adhesive G forms the multiple convex particles 11 on the inner surfaces of the two substrates 1; and electrically connecting the pulse generator 3 to the two substrates 1 respectively. In this embodiment, the active ion may be R5011 or S5011; the salt ion is a positive or negative ion decomposed by a salt dissolved in water or liquid crystal, and the salt may be sodium chloride (NaCl), calcium sulfate (CaSO4), sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), potassium nitrate (KNO3), tetrabutylammonium bromide (TBAB), tetrabutylammonium hydrogensulfate (TBAHS), tetrabutylammonium chloride (TBACl), tetrabutylammonium hexafluorophosphate (TBAHFP), tetrabutylammonium tetrafluoroborate (TBATFB), or the like; the photocurable adhesive G is a UV-curable adhesive, and the UV light has a wavelength of 357 nm and a light intensity of 80 mW / cm2. The exposure time is 30 minutes.

[0039] Figures 4 and 5 show the time-dependent haze values ​​and collimated light transmittance of a smart window with multiple convex particles according to the present invention and a conventional smart window without convex particles after the low-frequency pulse application ceases. As shown in Figure 4, within seven hours of no voltage application, the haze value of the smart window with convex particles remains around 90%, consistently providing excellent haze shielding. The haze value of the smart window without convex particles decreases with increasing exposure time. Furthermore, as shown in Figure 5, the collimated light transmittance of the smart window with convex particles remains around 10%, while that of the smart window without convex particles gradually increases to 40%. Collimated light transmittance is defined as the ratio of the intensity of the outgoing light within a diffusion angle of ±2.5 degrees to the intensity of the incoming light. It indicates the degree of deflection of the incoming light after passing through a light-transmitting layer. Lower collimated light transmittance indicates a more blurred image, resulting in a more privacy-preserving effect.

[0040] Please refer to Figures 6 and 7, which are comparison diagrams of the relationship between the applied pulse voltage value and the haze value and parallel light transmittance of the smart window with multiple convex particles of the present invention and the existing smart window without convex particles. As shown in Figure 6, the smart window with convex particles only requires a pulse voltage of 30 volts to achieve a haze value of 90%, while the smart window without convex particles requires a pulse voltage of at least 60 volts to increase the haze value to 80%; in addition, as shown in Figure 7, the parallel light transmittance of the smart window with convex particles can be as low as 10%, while the minimum parallel light transmittance of the smart window without convex particles is 20%. Therefore, compared with the existing smart windows, the smart window of the present invention can switch to the fogging state with a lower pulse voltage value, improve the effect of blocking parallel penetrating light, and enhance the fogging shielding effect.

[0041] In summary, the smart window and its manufacturing method of the present invention, by forming the multiple convex particles on the inner surfaces of the two substrates, can enable the liquid crystal layer located between the two substrates to maintain a fogged state in which the liquid crystal molecules are chaotically arranged, so that the liquid crystal layer can avoid gradually returning to a transparent state in which the liquid crystal molecules are neatly arranged when no pulse is applied, thereby enhancing the shielding effect of privacy protection and prolonging the duration of the fogged state.

[0042] Although the present invention has been disclosed using the above-mentioned preferred embodiments, they are not intended to limit the present invention. Those skilled in the art may make various changes and modifications to the above-mentioned embodiments without departing from the spirit and scope of the present invention. These changes and modifications still fall within the technical scope protected by the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A smart window, characterized in that: include: Two substrates are parallel and opposite to each other. The two substrates are transparent and conductive. Each substrate has a plurality of convex particles, and the plurality of convex particles are randomly distributed on the inner surfaces of the two substrates. A liquid crystal layer is filled between the two substrates with a liquid crystal material, wherein the liquid crystal material includes a negative liquid crystal, a helical molecule, a salt ion and an ultraviolet light curing adhesive; and A pulse generator is electrically connected to the two substrates respectively. The pulse generator switches and outputs a low-frequency pulse voltage and a high-frequency pulse voltage to form an electric field change between the two substrates.

2. The smart window according to claim 1, wherein: The pulse generator outputs the low-frequency pulse voltage to switch the smart window to a fogged state.

3. The smart window according to claim 1, wherein: The pulse generator outputs the high-frequency pulse voltage to switch the smart window to a transparent state.

4. The smart window according to claim 1, wherein: Each substrate includes a transparent conductive material, which is indium tin oxide, nano silver wire, conductive graphene or conductive ink.

5. The smart window according to claim 1, wherein: The ultraviolet curing glue is cured after exposure to light to form the plurality of convex particles.

6. The smart window according to claim 1, wherein: The frequency of the low-frequency pulse voltage is 60 Hz, and the frequency of the high-frequency pulse voltage is 5000 Hz.

7. A method for manufacturing a smart window, characterized in that: The following steps are involved: A liquid crystal material is filled between the two substrates to form a liquid crystal layer, wherein the liquid crystal material includes negative liquid crystal, helical molecules, salt ions and a photocurable adhesive; Expose the liquid crystal layer with ultraviolet light for an exposure time, so that the photocurable adhesive forms a plurality of convex particles on the inner surfaces of the two substrates; and A pulse generator is electrically connected to the two substrates respectively.

8. The method for manufacturing a smart window according to claim 7, wherein: The wavelength of the ultraviolet light was 357 nanometers and the light intensity was 80 milliwatts per square centimeter. The exposure time was 30 minutes.

Images