TWI702337B - Privacy protection film system - Google Patents

Abstract

A privacy protection film system, including privacy protection film and artificial light source, privacy protection The film has opposite directions to the inner side and the outer side. The inner side corresponds to the indoor artificial light source, and the outer side corresponds to the outdoor ambient light. The privacy protection film is composed of polymer film doped with dyes. The wavelength range of the artificial light source falls within the main absorption spectrum of the dye. When artificial light source is located indoors and penetrates towards the outer direction of the pair, it is directly absorbed by the dye; while ambient light is located in an outdoor environment and penetrates towards the inner direction, part of the ambient light is absorbed by the main absorption spectrum of the dye, and the rest is not absorbed. The dye mainly absorbs the ambient light outside the spectrum range and enters the room through the privacy protection film, so that people outside cannot see the indoor scene, but people indoors can see the outdoor scene.

Description

Privacy protection film system

The present invention relates to a thin film system, in particular, a membrane system that can be applied between indoor/in-car and outdoor/outdoor environments, providing that people outside/outdoor cannot see the scene inside/in the car, while people inside/in the car can see To the scene outside/outside the car.

At present, a variety of electronically controllable or light-controllable smart LCD windows have been widely studied. Such windows can be used for privacy protection or reducing direct sunlight to indoors to reduce indoor temperature. The following will briefly describe the various liquid crystal technologies used in the above-mentioned windows.

At present, the use of polymer dispersed liquid crystals (PDLCs) to make electrically controllable transmittance liquid crystal film windows has been commercialized. Such windows use a higher weight percentage polymer doped into positive liquid crystals , The liquid crystal ball is formed by irradiating ultraviolet light or heating and cooling, and the ordinary refractive index of the liquid crystal is similar to that of the polymer. The PDLC window is in a scattering state when no voltage is applied; and applying a proper voltage can make the liquid crystal molecules in the liquid crystal ball rotate to be perpendicular to the substrate and become a transparent state. For the above, please refer to books and papers [Reflective liquid crystal display.S.-T .Wu,D.-K.Yang.Wiley (2001); Liq.Cryst.Today 26(3),70-73(2017)].

Oh et al. also used dye-doped cholesteric liquid crystals to make smart light-controlled windows. You can refer to the paper [RSC Adv.7,19497-19501(2017)]. When there is no light, cholesteric liquid crystals are in a focal conic state. Light-transmitting state; the cholesteric liquid crystal changes to an isotropic state after being exposed to sunlight, and it is a penetrating state at this time.

Dabrowski and others also used smectic liquid crystals to make smart light-controlled windows, please refer to the paper [J.Mol.Liq.267,415-427(2018)]. In addition, polymer network liquid crystal and polymer network cholesteric liquid crystal can also be used to make smart electronically controlled windows. These two types of windows can be designed to be in a penetrating state when no voltage is applied, and the applied voltage is in a scattering state; polymer network cholesterol liquid crystal It can also be designed to be in the scattering state without voltage applied, and in the penetrating state under applied voltage. For the above, please refer to papers and books [Adv.Mater.12(3),167-181(2000); Reflective liquid crystal display.S. -T.Wu,D.-K.Yang.Wiley (2001)].

Other mixed liquid crystal materials such as polymer dispersion combined with polymer network liquid crystals studied by Guo et al., and mixed liquid crystal materials such as polymer dispersion combined with polymer network cholesteric liquid crystals; polymer network combined with polymer spheres in the polymer dispersion studied by Zhou et al. The mixed liquid crystal materials in the type liquid crystal can be used to make electronically controlled windows. Please refer to the above papers [Liq.Cryst.45,1854-1860(2018); ACS Appl.Mater.Interfaces 9,2942-2947(2017); RSC Adv .8, 21690-21698 (2018)].

Summary The above examples briefly describe various types of LCD smart windows. When they are opaque or foggy, outdoor people cannot see the indoor scene. Although it can protect the privacy of indoor people, indoor people cannot see the outdoor scenery. .

The present invention provides a privacy protection film system, which can prevent outdoor people from seeing the indoor scene, but indoor people can see the outdoor scene.

Three privacy protection film systems are provided below:

The first privacy protection film system includes a privacy protection film and an artificial light source. The privacy protection film has a pair of inner sides and a pair of outer sides in opposite directions to each other. The pair of inner sides corresponds to the artificial light source in the room, and the pair of The outside corresponds to the outdoor ambient light, the privacy protection film It is composed of transparent material doped with singular/plural dyes, the wavelength range of the artificial light source falls within the main absorption spectrum range of the singular/plural dye, and when the artificial light source is located indoors and penetrates toward the outside of the pair The singular/plural dye absorbs; and when the ambient light is located in an outdoor environment and penetrates toward the inner side of the pair, part of the ambient light is absorbed by the main absorption spectrum range of the singular/plural dye. When the intensity of the ambient light exceeds The absorption capacity of the wavelength within the main absorption spectrum of the singular/plural dye. This part of the ambient light cannot be completely absorbed, or part of it can pass through the inner side of the privacy protection film to the room, while the rest is not in the aforementioned singular/ The ambient light absorbed by the plural dyes mainly in the spectrum range can pass through the inner side of the privacy protection film to the room.

The second privacy protection film system includes a privacy protection film and an artificial light source. The privacy protection film has a pair of inner sides and a pair of outer sides in opposite directions to each other. The pair of inner sides corresponds to the indoor artificial light source, and the pair of outer sides Corresponding to outdoor ambient light, the privacy protection film includes: a transparent box, the two sides of which correspond to the outer side and the inner side respectively, the transparent box includes a transparent empty box and more than transparent material injected into the transparent empty box, and The transparent material is doped with singular/plural dichroic dyes, and the wavelength range of the artificial light source falls within the main absorption spectrum range of the singular/plural dichroic dye; the artificial light source is located indoors and penetrates the pair of outer directions. When passing through, it is directly absorbed by the singular/plural dichroic dye; and when the outdoor ambient light penetrates from the outer side of the pair to the inner side of the pair, the part of the ambient light is mainly absorbed by the singular/plural dichroic dye Absorption spectrum range, but when the intensity of this part of the ambient light exceeds its wavelength within the main absorption spectrum of the singular/plural dichroic dye, this part of the ambient light cannot be completely absorbed, or part of it Passing the inner side of the privacy protection film to the room, light outside the main absorption spectrum of the singular/plural dichroic dye can enter the room through the inner side of the privacy protection film.

The third privacy protection film system includes a privacy protection film and an artificial light source. The privacy protection film has a pair of inner sides and a pair of outer sides in opposite directions. The privacy protection film includes: a transparent box close to the pair On the outside, the transparent box includes a transparent empty cell and cholesteric liquid crystal injected into the transparent empty cell, and the cholesteric liquid crystal is in a planar state; a linear polarizer, which is close to the inner side; and a wave plate, which is located in the transparent box and Between the linear polarizers, and the aforementioned wave plate is a broadband quarter-wave plate; the artificial light source whose wavelength range falls within the reflection spectrum of the cholesteric liquid crystal is converted into a light source through the pair of inner sides through the linear polarizer and the wave plate The rotation of circularly polarized light is consistent with that of the cholesteric liquid crystal, so the circularly polarized light is reflected by the cholesteric liquid crystal in the transparent box and cannot penetrate the privacy protection film; while the ambient light, part of it falls on the cholesterol The light in the reflection spectrum of the liquid crystal is reflected by the cholesteric liquid crystal of the transparent cell through the pair of outer sides, and only the circularly polarized light whose rotation is opposite to that of the cholesteric liquid crystal remains, and the circularly polarized light is converted into linearly polarized light by the wave plate And it is absorbed by the linear polarizer, and part of the unpolarized light that does not fall within the reflection spectrum of the cholesteric liquid crystal remains unpolarized light after passing through the transparent box and the wave plate, and is partially absorbed after passing through the linear polarizer , And the remaining light can enter the room through the inner side of the privacy protection film.

1: Privacy protection film

11: To the inside

12: To the outside

2: Transparent box

3: Linear polarizer

4: wave board

5: Control circuit

The first figure is a schematic diagram of the application of the first and second privacy protection film systems of the present invention between indoor and outdoor environments.

The second figure is a schematic diagram of the artificial light source and ambient light path of the third privacy protection film system of the present invention.

The third figure is a schematic diagram of the simulated artificial light source and the ambient light path after voltage is applied to the third privacy protection film system of the present invention.

The fourth figure is a schematic diagram showing the path of simulated artificial light source and ambient light after applying a higher voltage to the third privacy protection film system of the present invention.

The fifth graph is the penetration rate versus wavelength test graph of the third privacy protection film system of the present invention.

The sixth figure is a schematic diagram of the three-layer cholesteric liquid crystal separated by a transparent box in the third privacy protection film system of the present invention.

The seventh diagram is a diagram of the transmittance and wavelength of each layer of cholesteric liquid crystal in the sixth configuration.

The eighth figure is the test chart of the penetration angle of the artificial light source from indoor to outdoor by the third privacy protection film system of the present invention with 589 nanometers of light.

Please refer to the first figure. This is the first privacy protection film system of the present invention. In the figure, the dashed arrow indicates the path of the artificial light source, and the path of the artificial light source is from the inner side 11 to the outer side 12, and the real The line arrows indicate the path of the ambient light, and the path of the ambient light is from the opposite side 12 to the opposite side 11 direction. The first privacy protection film system of the present invention includes a privacy protection film 1 and an artificial light source. The privacy protection film 1 has a pair of inner sides 11 and a pair of outer sides 12 in opposite directions. Light source, and the aforementioned pair of outer sides 12 correspond to outdoor ambient light, the privacy protection film 1 is composed of a polymer film doped with three dyes; the aforementioned three dyes include three absorption spectrum ranges, namely the blue range, the green range and the red range. Light range (for the range of the aforementioned three absorption spectrum ranges, please refer to the paper [ACS Sens. 1, 17-21(2016); J. Food Drug Anal. 23, 447-452(2015); Materials 2, 1636-1661(2009) ; J. Phys. Chem. C 120, 11151-11162 (2016)], the aforementioned artificial light source has a wavelength range that falls within the main absorption spectrum of the three dyes; wherein the artificial light source is located indoors and penetrates 12 directions outside the pair When it is transparent, it is directly absorbed by the three dyes; and when the ambient light is unpolarized light with a wavelength of 400 nm to 700 nm and penetrates toward the inner side of the pair in an outdoor environment, part of the ambient light is composed of the aforementioned three dyes The main absorption spectrum range of this part, but when the intensity of this part of the ambient light exceeds the absorption capacity of its wavelength in the main absorption spectrum range of the three dyes, this part of the ambient light cannot be completely absorbed, and part of it can also pass through the privacy protection film 1 The inner side 11 of the privacy protection film 1 enters the room, and the rest of the ambient light not absorbed by the aforementioned three dyes' main absorption spectrum range can pass through the inner side 11 of the privacy protection film 1 to the room.

It must be noted that in all the descriptions and drawings in the embodiment of the present invention, the aforementioned inner side 11 refers to the indoor/inside direction as an example, and the aforementioned outer side 12 refers to the outdoor/outdoor direction as an example.

In the above-mentioned first privacy protection film system, the ambient light outside/outside the car has an unpolarized light with a wavelength ranging from 400 to 700 nanometers, and the aforementioned artificial light source is a white light source that emits blue, green, and red light. Blue LED, green LED and red LED, this type of white light source can refer to the paper [Proc.IEEE 93,1691-1703(2005); Appl.Phys.Lett.80,234(2002)], and blue LED, The blue light, green light and red light emitted by the green LED and the red light LED fall within the main absorption spectrum range of blue light, the main absorption spectrum range of green light, and the main absorption spectrum range of red light of the three doped dyes, so artificial The light source can be almost absorbed by the dye. The ambient light located outdoors/outside the car is unpolarized light and its wavelength ranges from 400 to 700 nanometers. Therefore, when the ambient light enters the privacy protection film 1 from the opposite side 12, the part of the ambient light is mainly composed of the three dyes mentioned above. Absorption spectrum range, but when the intensity of this part of the ambient light exceeds its wavelength in the main absorption spectrum of the three dyes, this part of the ambient light cannot be completely absorbed, and it can also partially pass through the privacy protection film 1. From the inner side 11 to the room, the light whose wavelength is outside the main absorption spectrum of the three doped dyes can pass through the inner side 11 of the privacy protection film 1 to the room. According to the above, people indoors/in the car can see the scene outdoors/outside the car, while people outside the car cannot see the scene indoors/in the car.

The second privacy protection film system listed below of the present invention is roughly as shown in the first figure of the foregoing drawings.

Please refer to the first figure. In the figure, the dashed arrow represents the path of the artificial light source, and the path of the artificial light source is from the inner side 11 to the outer side 12, and the solid arrow represents the ambient light path, and the ambient light path is From the opposite side 12 to the opposite side 11 direction. The second privacy protection film system of the present invention includes a privacy protection film 1 and an artificial light source. The privacy protection film 1 has a pair of inner sides 11 and a pair of outer sides 12 in opposite directions. The aforementioned pair of inner sides 11 correspond to indoor Artificial light source, and the aforementioned pair of outer sides 12 correspond to outdoor ambient light. The privacy protection film 1 includes: a transparent box 2 whose two sides correspond to the pair of outer sides 12 and the pair of inner sides 11 respectively. The transparent box 2 includes a transparent hollow A box and a transparent substance injected into the transparent empty box, and the transparent substance is doped with three dichroic dyes, the wavelength range of the artificial light source falls within the main absorption spectrum range of the three dichroic dyes; the three dichroic dyes Sex dyes include three absorption spectrum ranges, including blue, green and red light ranges. For the three absorption spectrum ranges, please refer to the following papers [Materials 2,1636-1661(2009); Phys.Chem.Chem.Phys.18 , 20651-20663 (2016); J. Phys. Chem. C 120, 11151-11162 (2016)]; the aforementioned artificial light source is directly absorbed by the three dichroic dyes when it is located indoors and penetrates toward the outer side of the pair of 12 directions; and When the outdoor ambient light penetrates from the pair of outer sides 12 to the pair of inner sides 11, part of the ambient light is absorbed by the main absorption spectrum range of the aforementioned three dichroic dyes, but when the intensity of this part of the ambient light exceeds its The absorption capacity of the wavelength in the main absorption spectrum of the three dichroic dyes. This part of the ambient light cannot be completely absorbed, so it can also partly pass through the inner side 11 of the privacy protection film 1 to the room. The light outside the main absorption spectrum of the three dichroic dyes can enter the room through the inner side 11 of the privacy protection film 1.

In the second privacy protection film system of the present invention, the transparent material injected into the transparent empty cell in the second privacy protection film 1 listed above is cholesteric liquid crystal. Since the dichroic dye rotates with the pitch of the cholesteric liquid crystal, it can absorb artificial light sources in all polarization directions. For this part of the mechanism, please refer to the book [Reflective liquid crystal display.S.-T.Wu,D.-K.Yang.Wiley (2001)]. The ambient light located outdoors/outside the car has unpolarized light with a wavelength ranging from 400 to 700 nanometers. The aforementioned artificial light source is a white light source composed of a blue LED, a green LED and a red LED that emit blue, green, and red light. , And the blue, green, and red light emitted by the blue, green, and red LEDs fall within the blue, green, and red absorption spectrum of the three dichroic dyes. Within the spectrum range, artificial light sources can almost be absorbed by three dichroic dyes. The ambient light located outdoors/outside the car is unpolarized light and its wavelength ranges from 400 to 700 nanometers. Therefore, when the ambient light enters the privacy protection film 1 from the opposite side 12, the part of the ambient light is composed of the aforementioned three dichroisms. The dye's main absorption spectrum is absorbed, but when the intensity of this part of the ambient light exceeds its wavelength in the main absorption spectrum of the three dichroic dyes, this part of the ambient light cannot be completely absorbed, so it can also be partially absorbed. Passing through the opposite inner side 11 of the privacy protection film 1 to the room, the light whose wavelength is outside the main absorption spectrum of the three dichroic dyes can pass through the privacy protection film 1. According to the above, people indoors/in the car can see the scene outdoors/outside the car, while people outside the car cannot see the scene indoors/in the car. In addition, it must be noted that the concentration of the three dyes and the three dichroic dyes doped with the first and second privacy protection films 1 of the present invention must be sufficient to absorb close to 100% in the main absorption spectrum. The above-mentioned wavelength range falls within the artificial light source whose main absorption spectrum of the three dyes and the three dichroic dyes are, and the type of the dichroic dye or doped dye is not limited to only three.

Please refer to the second and third figures. This is the third privacy protection film system of the present invention. It includes a privacy protection film 1 and an artificial light source. The privacy protection film 1 has a pair of inner sides 11 and a pair of opposite directions. On the outer side 12, the privacy protection film 1 includes: a transparent box 2, which is close to the pair of outer sides 12. The transparent box 2 includes a transparent empty box and a right-handed cholesteric liquid crystal injected into the transparent empty box, and the right-handed cholesteric liquid crystal In a planar state; a linear polarizer 3, which is close to the inner side 11; and a wave plate 4, which is located between the transparent box 2 and the linear polarizer 3, and the aforementioned wave plate 4 is a broadband quarter wave Plate; The artificial light source whose wavelength range falls within the reflection spectrum of the right-handed cholesteric liquid crystal is converted into right-handed circularly polarized light through the pair of inner sides 11 through the linear polarizer 3 and the wave plate 4, and its rotation and rotation of the cholesteric liquid crystal Therefore, the right-handed circularly polarized light is reflected by the right-handed cholesteric liquid crystal in the transparent box 2 and cannot penetrate the privacy protection film 1; and the unpolarized light in the wavelength range of 400 to 700 nanometers of ambient light, part of it The light falling in the reflection spectrum of the right-handed cholesteric liquid crystal is reflected by the right-handed cholesteric liquid crystal of the transparent cell 2 through the pair of outer sides 12, and only left-handed circularly polarized light with the opposite rotation of the cholesterol liquid crystal remains. The light is converted into linearly polarized light by the wave plate 4 and is absorbed by the linear polarizer 3, while the unpolarized light, a part of which does not fall in the reflection spectrum of the right-handed cholesteric liquid crystal, remains after passing through the transparent box 2 and the wave plate 4. It is non-polarized light, and is partially absorbed after passing through the linear polarizer 3, and the remaining light can enter the room through the opposite inner side 11 of the privacy protection film 1.

The aforementioned transparent box 2, linear polarizer 3, and wave plate 4 are superimposed on each other, and the second and third figures show the transparent box 2, linear polarizer 3, and wave plate 4 separated to facilitate drawing the light path trajectory; The dashed arrow indicates the path of the artificial light source from the inner side 11 to the outer side 12, and the solid arrow indicates the path of the ambient light from the opposite side 12 to the inner side 11. For the above optical characteristics, please refer to the book [Reflective liquid crystal display.S] .-T.Wu,D.-K.Yang.Wiley (2001)].

As shown in the second and third figures, the privacy protection film 1 of the present invention can be applied between indoor and outdoor environments, or between the inside of the car and the outside of the car, and the dotted arrow indicates the direction from indoor/inside to outdoor/outside. The artificial light source path, and the solid arrow indicates the ambient light path from the outdoor/outside the car to the indoor/inside the car. Through the above description, it can be seen that when the artificial light source on the inner side 11 faces the opposite side 12, the linear polarizer 3 and The wave plate 4 is converted into right-handed circularly polarized light. This right-handed circularly polarized light is reflected by the right-handed cholesteric liquid crystal in the transparent box 2, so the artificial light source cannot penetrate the privacy protection film 1, so that people on the outer side 12 cannot pass through The privacy protection film 1 sees the scene in the room/car in the direction of the inner side 11. The ambient light on the outer side 12 is unpolarized light with a wavelength range of 400 to 700 nanometers, and part of the light falling in the reflection spectrum of the right-handed cholesteric liquid crystal is reflected by the right-handed cholesteric liquid crystal of the transparent cell 2 through the pair of outer sides 12 Only left-handed circularly polarized light is left. After the left-handed circularly polarized light passes through the wave plate 4, it is converted into linearly polarized light and absorbed by the linear polarizer 3, while the unpolarized light partially falls outside the reflection spectrum of the right-handed cholesteric liquid crystal. The transparent box 2 and the wave plate 4 are still unpolarized light, and then part of the light is absorbed after passing through the linear polarizer 3, and the remaining light can pass through the pair of inner sides 11, so as to be located in the room/car in the direction of the inner side 11 People can see the outdoor/outdoor scenes on the outside 12 directions through the aforementioned remaining light.

The aforementioned transparent empty box includes a combination of a plurality of glass substrates, and the privacy protection film 1 can be directly made into the glass surface of a window.

The aforementioned transparent empty box includes a combination of a plurality of plastic substrates, and the privacy protection film 1 can be adhered to the glass surface of a common window or a curved window glass surface. After a transparent conductive film is plated on the inside of the plurality of plastic substrates and voltage is applied, the right-handed cholesteric liquid crystal switches from a planar state to a focal conic state (this state is a scattering state), which can scatter all visible light. In this state, outdoor/ People outside the car cannot clearly see the scene inside/in the car, and people inside/in the car cannot see the scene outside/outside the car clearly. As shown in the third figure, the dotted arrow indicates that the indoor/inside the car faces the outdoors /Path of artificial light source outside the vehicle, The solid arrow indicates the path of the ambient light from the outdoor/outside the vehicle to the indoor/inside the vehicle. When a higher voltage is applied, the right-handed cholesteric liquid crystal is switched from the planar state to the vertical transmission state, that is, the positive liquid crystal molecules of the right-handed cholesteric liquid crystal are rotated to the direction perpendicular to the substrate. In this state, people outside/outdoor You can clearly see the scene inside/in the car, and people inside/in the car can also see the scene outside/outside the car clearly. As shown in the fourth figure, the dotted arrow indicates the direction from indoor/inside to outdoor/outside of the car. The path of artificial light source, and the solid arrow indicates the path of ambient light from the outdoor/outside the car to the indoor/inside the car. The aforementioned voltage application is executed by the control circuit 5. Please refer to the book [Reflective liquid crystal display.S.-T.Wu, D.-K.Yang.Wiley (2001)] for the mechanism of the above-mentioned cholesteric liquid crystal changing shape due to the applied voltage.

The artificial light source used above is based on the use of a red light source (helium-neon laser with a wavelength of 633 nanometers) as an example. Therefore, the artificial light source is doped with a 35.1% right-handed chiral molecule CB15 (Merck) in weight percentage. In the 64.9% positive type liquid crystal HFW59200-200 (Fusol Mate rials), a right-handed cholesteric liquid crystal with a reflection/transmission spectrum containing a wavelength of 633 nm was prepared. In addition, the ambient light is simulated using a flashlight. When the right-handed cholesteric liquid crystal is in a planar state, the penetration of the aforementioned artificial light source (helium-neon laser with a wavelength of 633 nanometers) light passing through the privacy protection film 1 is simulated outdoors/outside the car. This penetration rate is less than 1%. As shown in the fifth figure, the diamond-shaped dots in the figure indicate the penetration rate value position of the aforementioned artificial light points, which can indicate that the artificial light sources in the indoor/car cannot pass through the privacy protection film 1; and The blue curve in the five figures is the transmittance curve of the outdoor/outdoor ambient light (flashlight) measured in the laboratory simulation indoor/in the car through the privacy protection film 1, except for the light whose wavelength range is in the reflection spectrum of the right-handed cholesterol liquid crystal In other wavelength ranges, about 10%~26% of the light will enter the room/car through the privacy protection film 1. This amount of light is sufficient to allow people in the room/car to see the scene outside/outside the car. Therefore, according to the foregoing description and the support of the fifth figure, it is proved that people inside/in the car can see the scene outside/outside the car, but people outside/outside the car cannot see the scene inside/in the car.

The aforementioned artificial light source can also be used as a white light source (light emitting diode (LED)), which is composed of red, green, and blue LEDs, which emit red, green, and blue light, respectively. For the white light source, please refer to the paper [Proc.IEEE 93,1691-1703(2005); Appl.Phys.Lett.80,234(2002), for which three layers of right-handed cholesteric liquid crystals are separately arranged in the transparent box 2 as shown in Figure 6. As shown (indicated by three colors of red, green and blue), in order to make the three-layer cholesteric liquid crystal suitable for the wavelength range of the artificial white light from the inner side 11 to the outer side 12 of the pair to achieve privacy protection, such as As shown in the seventh figure, the red, green, and blue spectrums of the above three red, green, and blue LEDs must be within the red reflection/penetration spectrum range of the three-layer right-handed cholesteric liquid crystal range (No. The red spectrum of the seventh picture), the green reflection/transmission spectrum range (the green spectrum of the seventh picture) and the blue reflection/transmission spectrum (the blue spectrum of the seventh picture), and according to the description and Therefore, the artificial light source of the white light source inside/in the car cannot penetrate the privacy protection film, so that people outside/outside the car cannot see the scene inside/in the car, but people inside/in the car can still see the outdoor/outside car scene.

Please refer to the eighth figure, which is the third embodiment of the privacy protection film system and according to the description and use mechanism of the aforementioned second picture, the simulated artificial light source is 589 nanometers of light incident on the privacy protection film 1 at different angles. Penetration map. The right-handed cholesteric liquid crystal has an ordinary refractive index of 1.489 and an extraordinary refractive index of 1.597, and the right-handed cholesteric liquid crystal has a pitch of 395 nm. In addition, the blue area in the eighth figure represents that the penetration of the artificial light source (589 nm of light) in the indoor/car is close to 0, which means that the privacy protection film 1 cannot be penetrated.

The above descriptions are only used to explain the preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Therefore, all the inventions related to the present invention are made under the same inventive spirit. Any modification or alteration of any other type that can be implemented and has the same effect should still be included in the scope of the present invention.

1: Privacy protection film

11: To the inside

12: To the outside

2: Transparent box

Claims (5)

A privacy protection film system includes a privacy protection film and an artificial light source. The privacy protection film has a pair of inner sides and a pair of outer sides in opposite directions. The pair of inner sides correspond to the indoor artificial light source, and the pair of outer sides correspond to the outdoor The privacy protection film includes: a transparent box, the two sides of which correspond to the outer side and the inner side respectively, the transparent box includes a transparent empty box and a transparent substance injected into the transparent empty box, and the transparent substance Doped with singular/plural dichroic dyes, the wavelength range of the aforementioned artificial light source falls within the main absorption spectrum range of the singular/plural dichroic dye; the aforementioned transparent empty cell includes a combination of plural glass substrates or plural plastic substrates; The aforementioned artificial light source is directly absorbed by the singular/plural dichroic dye when it penetrates toward the outer side of the pair of indoor light sources; and when the outdoor ambient light penetrates from the outer side of the pair to the inner side of the pair, part of the ambient light It is absorbed by the main absorption spectrum range of the singular/plural dichroic dye, but when the intensity of this part of the ambient light exceeds its wavelength within the main absorption spectrum range of the singular/plural dichroic dye, this Part of the ambient light cannot be completely absorbed, or part of it can pass through the opposite inner side of the privacy protection film to the room. Light outside the main absorption spectrum of the singular/plural dichroic dye can pass through the opposite inner side of the privacy protection film. Come indoors. The privacy protection film system according to claim 1, wherein the aforementioned transparent material is cholesteric liquid crystal. A privacy protection film system includes a privacy protection film and an artificial light source. The privacy protection film has a pair of inner sides and a pair of outer sides in opposite directions. The privacy protection film includes: A transparent box, which is close to the outside of the pair, the transparent box includes a transparent empty box and cholesteric liquid crystal injected into the transparent empty box, and the cholesteric liquid crystal is in a planar state; the cholesteric liquid crystal of the transparent box is a mixture including positive Type liquid crystal and chiral molecules; a linear polarizer, which is close to the inner side; and a wave plate, which is located between the transparent box and the linear polarizer, and the aforementioned wave plate is a broadband quarter wave plate; The artificial light source within the reflection spectrum of the cholesteric liquid crystal is converted into circularly polarized light through the pair of inner sides through the linear polarizer and the wave plate, and its rotation is consistent with that of the cholesteric liquid crystal, so the circularly polarized light passes through The cholesteric liquid crystal in the transparent box is reflected and cannot penetrate the privacy protection film; while the ambient light, part of the light falling in the cholesteric liquid crystal reflection spectrum is reflected by the cholesteric liquid crystal of the transparent box through the pair of outer sides and only left Circularly polarized light whose rotation is opposite to that of the cholesteric liquid crystal. The circularly polarized light is converted into linearly polarized light by the wave plate and absorbed by the linear polarizer, and part of the unpolarized light does not fall on the cholesteric liquid crystal reflection spectrum. The light inside is still unpolarized light after passing through the transparent box and the wave plate, and is partially absorbed after passing through the linear polarizer, and the remaining light can enter the room through the opposite inner side of the privacy protection film. The privacy protection film system according to claim 3, wherein the transparent empty box includes a combination of a plurality of glass substrates or a plurality of plastic substrates, and the inner side of the plurality of glass substrates or the plurality of plastic substrates is coated with a transparent conductive film and applied with a voltage The cholesteric liquid crystal is switched from a planar state to a focal conic state (scattering state), and a higher voltage is applied to the cholesteric liquid crystal to switch from a planar state to a vertical state (transmitting state). The privacy protection film system of claim 3 or claim 4, wherein three layers of cholesteric liquid crystal are separately arranged in the transparent empty box, and they can reflect light in the red, green, and blue ranges respectively, in order to make the three layers Cholesterol liquid crystal can be used for artificial light from the inside of the pair to the outside of the pair The white light wavelength range of the source, where the red, green, and blue spectrums emitted by the white light wavelength range of the artificial light source must be in the red reflection/penetration spectrum range and green reflection/penetration of the aforementioned three-layer cholesteric liquid crystal, respectively Spectrum range and blue reflection/penetration spectrum range.

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