TWM499730U - Dimming device - Google Patents

Abstract

Disclosed herein is a dimming device including a dimming element and a polarizer on a side thereof. The dimming element includes a pair of parallel electrode layers; a porous film between the pair of parallel electrode layers, wherein the porous film has a refractive index and a plurality of pores arranged in a single direction; and a birefringent liquid crystal material filled in the pores of the porous film. The direction of the absorption axis of the polarizer is parallel to or perpendicular to the arranged direction of the pores. The dimming device is in transparent state without electric field, or is in opaque state with electric field.

Description

Dimming device

The present invention relates to a dimming device, and particularly relates to a reverse-phase polymer dispersed liquid crystal dimming device having an adjustable light passing through a transparent or opaque state.

With the development of smart glass and windows, the application of various light adjusting devices or light switching devices has increased. Conventionally, a polymer-dispersed liquid crystal (PDLC) dimming device is transparent or opaque under the action of an electric field, and can be distinguished as a transparent phase positive phase PDLC dimming device or an opaque reverse phase PDLC dimming device. Device. The application of the two types of PDLC dimming devices generally depends on the proportion of the time of the transparent state and the opaque state in use, for example, when used as a projection film, it is required to be in an opaque state for projection imaging for a long time. The use of normal phase PDLC dimming device; when used as a window, window or car head-up display projection film, etc., mainly need to be in a transparent state, and then switch to opaque state as needed, so that it has electronic curtain function or increase For display contrast, an inverted PDLC dimming device can be used. However, in order to maintain the transparent state during the power-off, the conventional reverse-phase PDLC dimming device must disperse the liquid crystal molecules in the polymer substrate, and the average refractive index of the liquid crystal molecules is consistent with the refractive index of the polymer, and must be suitable. Liquid crystal droplet size, shape and surface energy, so that the long axis direction of the liquid crystal molecules has a perpendicular to the surface of the substrate to. Therefore, the conventional reverse phase PDLC dimming device is more complicated than the normal phase PDLC dimming device in which the liquid crystal droplets can be randomly dispersed in the polymer substrate, and the degree of orientation under the unapplied electric field is generally not as good as the application of the electric field. The normal phase PDLC dimming device makes the transparent light transmission effect of the conventional reverse phase PDLC dimming device less clear than the normal phase PDLC dimming device.

In view of the above-mentioned problems of the traditional art, the purpose of the creation is to provide a dimming device with novelty, progressiveness and industrial utilization, etc., in order to overcome the difficulties of the existing products.

In order to achieve the above object, the present invention provides a dimming device comprising: a dimming element comprising a pair of parallel electrode layers; a porous film between the pair of parallel electrode layers, the porous film having a refractive index, and a hole of the porous film Having a single alignment direction; and a birefringent liquid crystal material filled in the pores of the porous film; and a polarizing layer disposed on one side of the dimming element. The absorption axis of the polarizing layer is parallel or perpendicular to the arrangement direction of the pores of the porous film. Since the dimming device has a polarizing layer structure, it can filter and absorb the incident light of the absorption axis component in half, so that the light passing through the porous film in the transparent state maintains the single direction transmission, and reduces the refraction of the incident light in the porous film in the absorption axis direction component. The scattering makes the dimming device have better definition than the general inverted PDLC dimming device, and the setting angle thereof can also be used in applications such as automotive glass to simultaneously reduce the reflection of external non-metallic objects. In addition, since the porous film and the polarizing layer have different color tones of their own materials, for example, a polyolefin-based porous film is generally white, and a polarizing layer is generally brownish-grey. Therefore, the reflectances on both sides of the dimming device are different, as Window, etc. In use, the porous film side is disposed on the light incident side, and the polarizing layer side can have a certain anti-peep effect.

In the dimming device of an embodiment, the biaxial liquid crystal material has an extraordinary refractive index (n _e ) in the long axis direction and an ordinary refractive index (n _o ) in the short axis direction; The refractive index of the porous film is the same as one of the extraordinary refractive index or the ordinary refractive index of the birefringent liquid crystal material.

In a dimming device of still another embodiment, the refractive index of the porous film is between 1.4 and 1.7.

In another embodiment of the dimming device, the difference in refractive index between the refractive index of the birefringent liquid crystal material and the refractive index of the ordinary light is between 0.2 and 0.25.

In another embodiment of the dimming device, the birefringent liquid crystal material is selected from the group consisting of smectic liquid crystal, cholesteric liquid crystal, rod liquid crystal, dish liquid crystal, column liquid crystal, polymer liquid crystal, twisted nematic liquid crystal, super twist A group consisting of nematic liquid crystals and combinations thereof.

In another embodiment, the substrate of the porous film is selected from the group consisting of a polyolefin polymer, a polyester polymer, a polyamine polymer, a polyvinylidene fluoride, and a combination thereof. .

In another embodiment of the dimming device, the pores of the porous membrane have an average pore diameter of from 0.01 μm to 0.2 μm and a porosity of from 30% to 90%.

In the dimming device of another embodiment, the polarizing layer is an absorption type polarizing plate, a reflective polarizing plate, a dyeing type polarizing plate, a coating type polarizing plate, a grating type polarizing plate, or a combination thereof.

1‧‧‧ dimming device

2‧‧‧ dimming components

21‧‧‧ parallel electrode layer

22‧‧‧Porous membrane

23‧‧‧ holes

24‧‧‧Birefringent liquid crystal material

3‧‧‧ polarizing layer

31‧‧‧Absorption axis

L‧‧‧ incident light

Ly‧‧‧Light

FIG. 1 is a schematic diagram of a dimming device according to an embodiment of the present invention; FIG. 2A and FIG. 2B are schematic diagrams showing the principle of generating a transparent state and an opaque state by a dimming device according to an embodiment of the present invention.

In order to make the creative features, content and advantages of the creation and the functions that can be achieved are more easily understood, the present invention is combined with the drawings and the following is a detailed description of the embodiments, and the schematic of the drawings used therein is For the purpose of illustration and supplementary manual, it is not necessarily the true proportion and precise configuration after the implementation of the original creation. Therefore, the scope and configuration relationship of the attached drawings should not be interpreted or limited. Explain first.

The embodiments of the dimming device according to the present invention will be described below with reference to the related drawings. For the sake of understanding, the same components in the following embodiments are denoted by the same reference numerals.

Referring to FIG. 1 , the present invention provides a dimming device 1 comprising: a dimming element 2 comprising a pair of parallel electrode layers 21; a porous film 22 between the pair of parallel electrode layers 21, the porous film 22 Has a refractive index, and the pores 23 of the porous membrane 22 have a single alignment direction; The refractive liquid crystal material 24 is filled in the hole 23 of the porous film 22; and the polarizing layer 3 is disposed on one side of the dimming element 2; wherein the absorption axis 31 of the polarizing layer 3 and the hole 23 of the porous film 22 are arranged in parallel or vertical.

In the dimming device of an embodiment, the birefringent liquid crystal material has an extraordinary refractive index in the long axis direction and an ordinary refractive index in the short axis direction; and the refractive index of the porous film and the extraordinary refractive index of the birefringent liquid crystal material Or one of the ordinary refractive indices is the same.

Please refer to FIG. 2A and FIG. 2B together, which is a schematic diagram of the principle of producing a transparent state and an opaque state of the dimming device according to an embodiment of the present invention. As shown in FIG. 2A, the birefringent liquid crystal material 24 is filled into the porous film 22 . After the holes 23, since the holes 23 have a single arrangement direction (x-axis direction), the birefringent liquid crystal material 24 is filled in the holes 23, and the major axis of the birefringent liquid crystal material 24 also has the same alignment direction. In the case where the refractive index of the porous film 22 selected is the same as the ordinary refractive index of the birefringent liquid crystal material 24, when an electric field is not applied to the porous film 22 in the parallel electrode layer (not shown), the birefringence The liquid crystal material 24 does not rotate and maintains the original direction. After the incident light L passes through the polarizing layer 3, the light in the x-axis direction is absorbed by the absorption axis 31 and cannot pass, and only the light ray Ly remaining in the y-axis direction component is penetrated. Since the direction of vibration of the light ray coincides with the short-axis direction (y-axis direction) of the birefringent liquid crystal material 24, the ordinary refractive index of the birefringent liquid crystal material 24 can be felt, and the refractive index of the porous film 22 and the birefringence The ordinary light refractive index of the liquid crystal material 24 is the same, and the light Ly does not refract at the interface between the porous film 22 and the birefringent liquid crystal material 24, but can directly penetrate to form a transparent state. As shown in FIG. 2B, when an electric field is applied to the porous film 22 in a parallel electrode layer (not shown), the double fold The liquid crystal material 24 is deflected by an angle to deflect the long axial y-axis direction, and the light ray that penetrates the polarizing layer 3 can simultaneously sense the extraordinary refractive index and x-axis component of the birefringent liquid crystal material 24 in the y-axis component. The ordinary refractive index is different, and since the refractive index of the porous film 22 is different from the extraordinary refractive index of the birefringent liquid crystal material 24, the light Ly is refracted at the interface between the porous film 22 and the birefringent liquid crystal material 24, and cannot be directly penetrated. Form an opaque state.

In a dimming device of still another embodiment, the refractive index of the porous film is between 1.4 and 1.7.

In another embodiment of the dimming device, the refractive index difference between the extraordinary refractive index of the birefringent liquid crystal material and the ordinary refractive index is between 0.2 and 0.25 to obtain a better difference between the transparent state and the opaque state.

In another embodiment of the dimming device, the birefringent liquid crystal material is selected from the group consisting of smectic liquid crystal, cholesteric liquid crystal, rod liquid crystal, dish liquid crystal, column liquid crystal, polymer liquid crystal, twisted nematic liquid crystal, super twist A group consisting of nematic liquid crystals and combinations thereof.

In another embodiment, the substrate of the porous film is selected from the group consisting of a polyolefin polymer, a polyester polymer, a polyamine polymer, a polyvinylidene fluoride, and a combination thereof. .

In the dimming device of another embodiment, the porous film having different average pore diameters and porosity may be adjusted depending on the degree of light transmission required, and the average pore diameter of the pores of the porous film is between 0.01 μm and 0.2 μm, and the porosity is Between 30% and 90%.

In another embodiment, the polarizing layer is an absorption type polarizing plate, a reflective polarizing plate, a dyeing type polarizing plate, a coating type polarizing plate, A grating type polarizing plate or a combination thereof.

The embodiments described above are only for explaining the technical idea and characteristics of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement them according to the scope of the patent. That is, the equivalent changes or modifications made by the people in accordance with the spirit revealed by this creation should still be covered by the scope of the patent of this creation.

1‧‧‧ dimming device

2‧‧‧ dimming components

21‧‧‧ parallel electrode layer

22‧‧‧Porous membrane

23‧‧‧ holes

24‧‧‧Birefringent liquid crystal material

3‧‧‧ polarizing layer

31‧‧‧Absorption axis

Claims (10)

A dimming device comprising: a dimming element comprising a pair of parallel electrode layers; a porous film between the pair of parallel electrode layers, the porous film having a refractive index, and the holes of the porous film having a single alignment direction And a birefringent liquid crystal material is filled in the hole of the porous film; and a polarizing layer is disposed on one side of the dimming element, wherein an absorption axis of the polarizing layer is parallel or perpendicular to a direction in which the hole of the porous film is arranged . The dimming device of claim 1, wherein the refractive index of the porous film is between 1.4 and 1.7. The dimming device of claim 1, wherein the birefringent liquid crystal material has an extraordinary refractive index in a long axis direction and an ordinary refractive index in a short axis direction. The dimming device of claim 3, wherein the refractive index of the porous film is the same as one of an extraordinary refractive index or an ordinary refractive index of the birefringent liquid crystal material. The dimming device of claim 3, wherein the refractive index difference between the extraordinary refractive index of the birefringent liquid crystal material and the ordinary refractive index is between 0.2 and 0.25. The dimming device of claim 1, wherein the birefringent liquid crystal material is selected from the group consisting of smectic liquid crystal, cholesteric liquid crystal, rod liquid crystal, dish liquid crystal, column liquid crystal, polymer liquid crystal, and twisted nematic A group of liquid crystals, super twisted nematic liquid crystals, and combinations thereof. The dimming device according to claim 1, wherein the substrate of the porous film is selected from the group consisting of a polyolefin polymer, a polyester polymer, a polyamine polymer, a polyvinylidene fluoride, and a combination thereof. The group formed. The dimming device of claim 1, wherein the pores of the porous membrane have an average pore diameter of from 0.01 μm to 0.2 μm. The dimming device of claim 1, wherein the porous film has a porosity of between 30% and 90%. The dimming device according to claim 1, wherein the polarizing layer is an absorbing polarizing plate, a reflective polarizing plate, a dyeing polarizing plate, a coating polarizing plate, a grating polarizing plate, or a combination thereof.