CN115236905A - Reflecting device based on cholesteric liquid crystal - Google Patents

Reflecting device based on cholesteric liquid crystal Download PDF

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CN115236905A
CN115236905A CN202211012876.9A CN202211012876A CN115236905A CN 115236905 A CN115236905 A CN 115236905A CN 202211012876 A CN202211012876 A CN 202211012876A CN 115236905 A CN115236905 A CN 115236905A
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liquid crystal
light
crystal element
cholesteric liquid
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王勇竞
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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1347—Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
    • G02F1/13478—Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells based on selective reflection
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/137—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
    • G02F1/13718—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on a change of the texture state of a cholesteric liquid crystal

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  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mathematical Physics (AREA)
  • Liquid Crystal (AREA)

Abstract

The invention discloses a reflecting device based on cholesteric liquid crystal, which comprises a first liquid crystal element and a second liquid crystal element which are sequentially stacked. The cholesteric liquid crystal in the first liquid crystal element and the cholesteric liquid crystal in the second liquid crystal element are set to different chiralities and pitches, respectively. The first liquid crystal element and the second liquid crystal element are in a reflective state when the cholesteric liquid crystal itself is in a planar texture state, and are in a transparent state when the cholesteric liquid crystal itself is in a focal conic texture state or a despiralized state. The initial incident light reflects a first reflected polarized light of a first target wavelength through the first liquid crystal element in the reflective state, and the light of the remaining wavelength band reflects a second reflected polarized light of a second target wavelength through the second liquid crystal element in the reflective state. Through this kind of setting, need not to set up the polaroid and can realize controlling the polarized light of different chiralities. The reflecting device can be in a reflecting state, a transparent state or a scattering state, is applied to the fields of automobile windows, building glass and the like, and plays roles in protecting privacy, saving energy, adjusting and the like.

Description

Reflecting device based on cholesteric liquid crystal
Technical Field
The invention relates to the technical field of optical devices, in particular to a reflecting device based on cholesteric liquid crystal.
Background
The technical scheme for realizing the controllable reflector mainly adopts various liquid crystal devices, electrochromic technology, electrophoresis technology and the like at present. The technology of changing the transmittance, reflectivity and color of the glass by means of electricity or heat has great application in the aspects of intelligent windows, intelligent glass, even intelligent glasses and the like. Such controllable mirrors are mostly varied between a transparent state and a light absorbing state. The light absorption state is generally black, absorbs most of light energy, and is widely applied to automobile glass and building glass. The reflecting mirror applied at present puts higher requirements on the service life, reliability, heat dissipation, energy conservation and the like of a device because a large amount of heat is generated in an absorption state.
Therefore, controllable mirrors using cholesteric liquid crystal devices are also present on the market. Referring to fig. 1, cholesteric liquid crystal has three states: a planar texture 101, a focal conic texture 102, and a despiral texture 103. Cholesteric liquid crystals are also known as chiral nematic liquid crystals. They are organized in layers, with no positional order within the layers, but the pointing axis varies from layer to layer. The change in the director axis tends to be periodic in nature, and the period of the helix (the distance required to complete a 360 rotation) of this change is referred to as the pitch p. This pitch determines the wavelength of the light that is reflected (bragg reflection). The solution is characterized by stable states, i.e. a focal conic state (dark state) and a planar state (bright state).
However, the conventional mirror device using cholesteric liquid crystal only reflects one polarized light (left-handed light or right-handed light), has no effect on the other polarized light, and needs an additional circular polarizer to realize the control of natural light, and cannot simultaneously reflect polarized lights of different chiralities.
At present, a controllable reflector which has a simple structure and low cost, can reflect two polarization states simultaneously and reflect a wide spectral range is urgently needed, and is applied to the fields of intelligent mirrors, automobile windows, building outer walls and the like. The functions of protecting privacy, isolating space, controlling ambient light, regulating temperature and the like are realized.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the reflecting device based on the cholesteric liquid crystal is provided to solve the problem that the existing cholesteric liquid crystal reflecting mirror can not reflect light with different chiral polarizations under the condition of not arranging a polarizing film.
In order to solve the technical problems, the invention adopts the technical scheme that:
a cholesteric liquid crystal-based reflective device, comprising: a first liquid crystal element and a second liquid crystal element which are stacked in this order;
the cholesteric liquid crystal in the first liquid crystal element and the cholesteric liquid crystal in the second liquid crystal element are respectively set to different chirality and helical pitch;
the first liquid crystal element and the second liquid crystal element are in a reflection state when the cholesteric liquid crystal of the first liquid crystal element and the second liquid crystal element is in a planar texture state and are in a transparent state when the cholesteric liquid crystal of the first liquid crystal element and the second liquid crystal element is in a focal conic texture state or a despiral state;
the first liquid crystal element is used for receiving initial incident light, reflecting first reflection polarized light with a first target wavelength when the first liquid crystal element is in a reflection state, and providing the first incident light with a residual waveband for the second liquid crystal element;
the second liquid crystal element receives the first incident light and reflects second reflection polarized light with a second target wavelength when the second liquid crystal element is in a reflection state, and the second reflection polarized light is emitted outwards after passing through the first liquid crystal element.
Further, the cholesteric liquid crystal exists in three states: a focal conic texture state that effects scattering of light; a planar texture state that effects reflection of light; a despiralized state which achieves transmission of light. The reflecting device works in three states and is in a reflecting state when the cholesteric liquid crystal is in a planar texture state; the cholesteric liquid crystal is in a scattering state when in a focal conic texture state and in a high-transparency state when in a spiral state. Wherein the scattered state can be considered as another transparent state.
The reflected light wave of the cholesteric liquid crystal in a planar state has a bandwidth which is determined by the bifold coefficient deltan of the liquid crystal. The larger the Δ n, the larger its reflection bandwidth, and the closer its color is to white. Currently, Δ n of a conventional liquid crystal is from about 0.01 to 0.4, and a larger liquid crystal material is also under development. Δ n is 0.4, the reflection wavelength bandwidth is about 100 nm. In order to further adjust the reflected wave, increase the bandwidth of the wavelength of the reflected light and adjust the color temperature of the reflected light, the reflecting device based on the cholesteric liquid crystal further comprises a reflecting layer which is arranged on one side of the second liquid crystal element far away from the first liquid crystal element;
the second liquid crystal element is also used for providing a second incident light with a residual waveband to the reflecting layer;
the reflecting layer is used for receiving the second incident light and reflecting target reflected light of a third target waveband, and the target reflected light is emitted outwards after passing through the second liquid crystal element and the first liquid crystal element in sequence;
the target reflected light is complementary light of the first reflected polarized light and the second reflected polarized light. The combination of the two results in a wider reflection bandwidth for the reflective device.
Further, the first liquid crystal element comprises a first light-transmitting substrate, a first liquid crystal layer and a second light-transmitting substrate which are sequentially stacked;
the second liquid crystal element comprises a third light-transmitting substrate, a second liquid crystal layer and a fourth light-transmitting substrate which are sequentially stacked.
Further, the first light-transmitting substrate comprises a first electrode and a first alignment layer, and the second light-transmitting substrate comprises a second electrode and a second alignment layer;
the first electrode, the first alignment layer, the first liquid crystal layer, the second alignment layer, and the second electrode are sequentially stacked;
the third light-transmitting substrate comprises a third electrode and a third alignment layer, and the fourth light-transmitting substrate comprises a fourth electrode and a fourth alignment layer;
the third electrode, the third alignment layer, the second liquid crystal layer, the fourth alignment layer, and the fourth electrode are sequentially stacked.
Further, the first liquid crystal layer comprises a first cholesteric liquid crystal polymer network or first cholesteric liquid crystal polymer droplets and the second liquid crystal layer comprises a second cholesteric liquid crystal polymer network or second cholesteric liquid crystal polymer droplets.
Furthermore, the number of the spiral of the cholesteric liquid crystal of the first liquid crystal layer is 2-100 layers, and the birefringence coefficient is 0.01-0.9;
the spiral number of the cholesteric liquid crystal of the second liquid crystal layer is 2-100 layers, and the birefringence coefficient is 0.01-0.9.
Furthermore, a first separation structure is arranged between the first light-transmitting substrate and the second light-transmitting substrate, the first separation structure is respectively connected with the first light-transmitting substrate and the second light-transmitting substrate, and the first separation structure is used for separating the first liquid crystal layer into a plurality of first liquid crystal units;
and a second partition structure is arranged between the third light-transmitting substrate and the fourth light-transmitting substrate, the second partition structure is respectively connected with the third light-transmitting substrate and the fourth light-transmitting substrate, and the second partition structure is used for partitioning a second liquid crystal layer into a plurality of second liquid crystal units.
Further, the cholesteric liquid crystal-based reflective device further includes a first driver and a second driver;
the first driver is electrically connected with the first light-transmitting substrate and the second light-transmitting substrate respectively, and is used for driving the first liquid crystal element to be in a transparent state or a reflective state;
the second driver is electrically connected with the third transparent substrate and the fourth transparent substrate respectively, and the second driver is used for driving the second liquid crystal element to be in a transparent state or a reflective state.
Further, the cholesteric liquid crystal of the first liquid crystal element and the cholesteric liquid crystal of the second liquid crystal element are respectively provided with pitches which reflect visible light of different wavelengths.
In the application scenario, the mirror controls visible light. Privacy settings can be adjusted by controlling the visible light, creating a partition, and even controlling the light entering the building, thereby controlling the temperature.
Further, the cholesteric liquid crystal of the first liquid crystal element and the cholesteric liquid crystal of the second liquid crystal element are respectively provided with pitches which reflect infrared light of different wavelengths.
Further, the cholesteric liquid crystal-based reflective device further includes: the temperature detector is electrically connected with the third driver and the fourth driver respectively and is used for detecting the ambient temperature and sending the detected temperature to the third driver and the fourth driver;
the third driver is used for driving the first liquid crystal element to be in a transparent state when the detection temperature is smaller than a preset temperature threshold value, and driving the first liquid crystal element to be in a reflecting state when the detection temperature is larger than or equal to the preset temperature threshold value;
the fourth driver is used for driving the second liquid crystal element to be in a transparent state when the detection temperature is smaller than a preset temperature threshold value, and driving the second liquid crystal element to be in a reflective state when the detection temperature is larger than or equal to the preset temperature threshold value. The reflector can automatically adjust light rays entering a building, and plays a role in cooling, energy conservation, emission reduction and cooling.
Further, the cholesteric liquid crystal of the first liquid crystal element and/or the cholesteric liquid crystal of the second liquid crystal element are temperature-sensitive cholesteric liquid crystals; the pitch of the temperature sensitive cholesteric changes with temperature, i.e. its reflection wavelength changes with temperature. Its reflection wavelength can be adjusted with temperature instead of being adjusted electrically. The liquid crystal element provided with the temperature sensitive cholesteric liquid crystal is used for reflecting infrared light when the ambient temperature is higher than the target temperature range and transmitting the infrared light when the ambient temperature is lower than the target temperature range, so that the effect of automatically adjusting the indoor temperature is achieved.
Further, the cholesteric liquid crystal-based reflective device further comprises a mechanical structure for auxiliary mounting and a plurality of electronic devices for auxiliary circuits;
the first liquid crystal element and the second liquid crystal element are arranged on the mechanical structure;
the electronic device is electrically connected to at least one of the first liquid crystal element and the second liquid crystal element directly or indirectly.
In another embodiment of the present invention, there is provided a reflective device based on cholesteric liquid crystal, comprising at least two liquid crystal elements arranged in a stack, the cholesteric liquid crystal of each of said liquid crystal elements being respectively configured with helical pitches reflecting light of different wavelengths, the multilayer liquid crystal elements being combined to achieve a larger reflection bandwidth;
the liquid crystal element is in a reflective state when the cholesteric liquid crystal of the liquid crystal element is in a planar texture state, and is used for reflecting light with corresponding wavelength, and is in a transparent state when the cholesteric liquid crystal of the liquid crystal element is in a focal conic texture state or a despiral state.
The invention has the beneficial effects that: 1. through setting up upper and lower two-layer liquid crystal element that has cholesteric liquid crystal, wherein first liquid crystal element reflects one of them polarized light, and second liquid crystal element reflects another polarized light to need not to set up the polaroid can reflect the polarized light of different chiralities simultaneously. 2. By adding the 3 rd mirror, the reflection wavelength bandwidth is increased, and better white balance can be realized.
Drawings
Fig. 1 shows three different operating states of cholesteric liquid crystals;
fig. 2 is a schematic view of a first structure of a cholesteric liquid crystal-based reflective device according to an embodiment of the present invention;
fig. 3 is a schematic view of a second configuration of a cholesteric liquid crystal-based reflective device in accordance with an embodiment of the invention;
FIG. 4 is a schematic diagram of a third structure of a cholesteric liquid crystal-based reflective device in accordance with an embodiment of the present invention;
fig. 5 is a fourth configuration diagram of a cholesteric liquid crystal-based reflective device according to an embodiment of the present invention;
fig. 6 is a schematic diagram of a fifth structure of a cholesteric liquid crystal-based reflective device according to an embodiment of the present invention.
Description of reference numerals:
FIG. 1:
101. a planar texture state; 102. focal conic texture state; 103. a despiralized state.
FIG. 2:
211. initial incident light; 212. a first reflected polarized light; 213. a second reflected polarized light; 220. a first liquid crystal element; 221. a first light-transmitting substrate; 222. a first liquid crystal layer; 223. a second light-transmitting substrate; 230. a second liquid crystal element; 231. a third light-transmitting substrate; 232. a second liquid crystal layer; 233. and a fourth light-transmitting substrate.
FIG. 3:
312. a first reflected polarized light; 313. a second reflected polarized light; 314. target reflected light; 320. a first liquid crystal element; 321. a first light-transmitting substrate; 323. a second light-transmitting substrate; 330. a second liquid crystal element; 331. a third light-transmitting substrate; 333. a fourth light-transmitting substrate; 340. a first driver; 350. a second driver; 360. and a reflective layer.
FIG. 4 is a schematic view of:
412. a first liquid crystal layer; 414. a first cholesteric liquid crystal polymer network; 422. a second liquid crystal layer; 424. a second cholesteric liquid crystal polymer network.
FIG. 5:
512. a first liquid crystal layer; 514. a first cholesteric liquid crystal polymer droplet; 522. a second liquid crystal layer; 524. a second cholesteric liquid crystal polymer droplet.
FIG. 6:
611. a first light-transmitting substrate; 612. a first liquid crystal layer; 613. a second light-transmitting substrate; 614. a first separation structure; 620. a second liquid crystal element; 621. a third light-transmitting substrate; 623. a fourth light-transmitting substrate; 624. a second partition structure.
Detailed Description
In order to explain technical contents, achieved objects, and effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.
Example one
The first embodiment of the invention is as follows: a reflector based on cholesteric liquid crystal is applied to wall glass of buildings, automobile windows and the like.
Referring to fig. 2, the reflective device includes: the first liquid crystal element 220 and the second liquid crystal element 230 are stacked in this order. The first liquid crystal element 220 and the second liquid crystal element 230 each contain cholesteric liquid crystal, and the cholesteric liquid crystal in the first liquid crystal element 220 and the cholesteric liquid crystal in the second liquid crystal element 230 are set to have different chirality and pitch, respectively. For example, when the cholesteric liquid crystal of the first liquid crystal element 220 reflects the left-handed circularly polarized light, the cholesteric liquid crystal of the second liquid crystal element 230 is modulated to reflect the right-handed circularly polarized light. The first liquid crystal element 220 and the second liquid crystal element 230 are in a reflective state when the cholesteric liquid crystal itself is in a planar texture state, and in a transparent state when the cholesteric liquid crystal itself is in a focal conic texture state or a despiralized state. The first liquid crystal element 220 is configured to receive an initial incident light 211, reflect a first reflected polarized light 212 of a first target wavelength when in a reflective state, and provide a remaining band of the first incident light to the second liquid crystal element 230. The second liquid crystal element 230 receives the first incident light and reflects a second reflected polarized light 213 with a second target wavelength when in a reflective state, and the second reflected polarized light 213 is emitted outward after passing through the first liquid crystal element 220. Wherein, when the cholesteric liquid crystal is in a planar texture state, the liquid crystal element is regarded as a reflective state; when the cholesteric liquid crystal is in a focal conic texture state or a deshelix state, the liquid crystal element is considered to be in a transparent state.
Further, in another embodiment of the present invention, the cholesteric liquid crystal exists in three states: a focal conic texture state that effects scattering of light; a planar texture state that effects reflection of light; a despiralized state which achieves transmission of light. The reflecting device works in three states and is in a reflecting state when the cholesteric liquid crystal is in a planar texture state; the cholesteric liquid crystal is in a scattering state when in a focal conic texture state and is in a high transparency state when in a helical state. Wherein the scattering state can be considered as another transparent state.
The structural principle of the reflecting device based on the cholesteric liquid crystal in the embodiment is as follows: the cholesteric liquid crystals in the first liquid crystal element 220 and the second liquid crystal element 230 have different chiralities, respectively. The liquid crystal cell is in a reflective state when the cholesteric liquid crystal itself is in a planar texture state, and is in a transparent state when the cholesteric liquid crystal itself is in a focal conic texture state or a despiral state. When the first liquid crystal element 220 and the second liquid crystal element 230 are in a reflective state, the initial incident light 211 passes through the first liquid crystal element 220 and reflects the first reflected polarized light 212 with the first target wavelength, the light with the remaining wavelength band passes through the second liquid crystal element 230 and reflects the second reflected polarized light 213 with the second target wavelength, and the light with the remaining wavelength band which is not reflected can be incident into the room. The first liquid crystal element 220 and the second liquid crystal element 230 are in a transparent state, and do not emit light of the first target wavelength and the second target wavelength. In one embodiment of the present invention, the first target wavelength and the second target wavelength are set to the same target wavelength, and the first liquid crystal element and the second liquid crystal element are combined to reflect two different polarizations of light, respectively, thereby performing a function of adjusting natural light. In a further embodiment of the invention, the first target wavelength and the second target wavelength are set to different target wavelengths. The two liquid crystal elements are combined to achieve control over a wider range of wavelengths.
It can be understood that the reflective device based on cholesteric liquid crystal of this embodiment employs the first liquid crystal element 220 and the second liquid crystal element 230 having cholesteric liquid crystals of different chiralities, respectively, and can effectively regulate and control natural light without providing a polarizing plate. In addition, compared with the case that only one liquid crystal element is adopted, the wave band of the light which can be reflected by the reflecting device is increased, and the adjusting capacity of the reflecting device based on the cholesteric liquid crystal to the ambient light is further improved. Illustratively, the first liquid crystal element 220 and the second liquid crystal element 230 are bonded together in a separated or glued manner.
Specifically, the first liquid crystal element 220 includes a first transparent substrate 221, a first liquid crystal layer 222, and a second transparent substrate 223 stacked in this order. The second liquid crystal element 230 includes a third transparent substrate 231, a second liquid crystal layer 232, and a fourth transparent substrate 233 which are stacked in this order.
In this embodiment, liquid crystal cells for accommodating liquid crystal are respectively formed between the first transparent substrate 221 and the second transparent substrate 223, and between the third transparent substrate 231 and the fourth transparent substrate 233, and the liquid crystal cells are filled with corresponding cholesteric liquid crystal. The transparent substrate is provided with electrodes for electrically connecting an external circuit and provides driving voltage for the corresponding liquid crystal layer so as to control the cholesteric liquid crystal in the corresponding liquid crystal layer to be in one of a planar texture state, a focal conic texture state and a despiral state.
Illustratively, the initial incident light 211 has a first target wavelength and a second target wavelength, the cholesteric liquid crystals in the first liquid crystal layer 222 are arranged to have a first helical period corresponding to reflection of light at the first target wavelength, and the cholesteric liquid crystals in the second liquid crystal layer are arranged to have a second helical period corresponding to reflection of light at the second target wavelength. When the cholesteric liquid crystals of the first liquid crystal layer 222 and the second liquid crystal layer 232 are both in a planar texture state, the initial incident light 211 enters the first liquid crystal layer 222 through the first light-transmitting substrate 221, the first liquid crystal layer 222 reflects light with a first target wavelength, the remaining light with a second target wavelength is emitted to the third light-transmitting substrate 231 through the second light-transmitting substrate 223 and enters the second liquid crystal layer 232 through the third light-transmitting substrate 231, and the second liquid crystal layer 232 reflects light with a second target wavelength, so that reflection of light with different wavebands is realized, and the reflection spectrum range of the reflection device is favorably increased.
Alternatively, the first transparent substrate 221 includes a first electrode and a first alignment layer, and the second transparent substrate 223 includes a second electrode and a second alignment layer (the electrode and the alignment layer are not shown in the drawings). The first electrode, the first alignment layer, the first liquid crystal layer 222, the second alignment layer, and the second electrode are sequentially stacked. The third transparent substrate 231 includes a third electrode and a third alignment layer, and the fourth transparent substrate 233 includes a fourth electrode and a fourth alignment layer. The third electrode, the third alignment layer, the second liquid crystal layer 232, the fourth alignment layer, and the fourth electrode are sequentially stacked.
It is understood that the light-transmitting substrate is electrically connected to an external circuit through electrodes and supplies a required driving voltage, and causes the liquid crystal molecules to have a mirror effect in a planar texture state, reflect light of a set wavelength, and cause the liquid crystal molecules to be in a transparent state in a focal conic texture state or a deshelix state through the alignment layer. In this embodiment, the electrodes on each liquid crystal element are transparent electrodes, and the transparent electrodes may be made of ITO (indium tin oxide), IZO (indium zinc oxide), nano silver thin film, or the like. It will be appreciated that by providing a light-transmissive substrate and a light-transmissive electrode on the light-transmissive substrate, it is advantageous to avoid losing part of the wavelength band of the incident light when the liquid crystal cell is in the transparent state. In the present embodiment, the transparent substrate is a hard glass substrate, and in other embodiments, the transparent substrate is a flexible plastic substrate, and illustratively, the flexible plastic substrate may be made of one or more materials independently selected from silicon, silicon oxide, silicon carbide, PET, PEN, and the like.
The bragg reflection phenomenon is caused by the change of the optical rotation ability of the liquid crystal layer, when the cholesteric liquid crystal is in a planar texture state, light within a certain specific wavelength range is reflected due to the periodic arrangement structure, the phenomenon is called bragg reflection, and the central wavelength of the reflection waveband is called the central wavelength lambda of the bragg reflection 0 The wavelength range width is referred to as a band width Δ λ.
At normal incidence, the wavelength λ of the reflected light 0 Determined by the period of the helical structure and the average refractive index of the liquid crystal.
Figure BDA0003811599510000091
Wherein
Figure BDA0003811599510000092
Is the average refractive index of the liquid crystal material,
Figure BDA0003811599510000093
wherein n is o And n e The refractive indices of ordinary light and extraordinary light, respectively; p is the pitch of the cholesteric liquid crystal.
Δλ＝pΔn，
Where Δ λ is called the reflection bandwidth, Δ n is the birefringence coefficient of the liquid crystal material, Δ n = n e -n o 。
In the planar state, the reflectivity of the cholesteric liquid crystal structure is:
Figure BDA0003811599510000101
in the formula of lambda 0 Is Bragg central reflection wavelength, and Delta lambda is Bragg reflection wavelength band, R 0 Is the optical rotation capability, i.e., reflectivity, of the cholesteric liquid crystal layer. The optical rotation capacity is positive and negative values on two sides of Bragg reflection central wavelength respectively, and represents levorotation and dextrorotation.
Different chiral agents are doped in the liquid crystal to determine the period of the liquid crystal helix, and the wavelength of the reflected light can be determined by adopting the liquid crystals with different average refractive indexes. The reflectivity of the cholesteric liquid crystal structure in turn depends on the number of helices and the birefringence coefficient of the liquid crystal. In order to achieve a larger reflection coefficient, in this embodiment, the number of helices of cholesteric liquid crystal of the first liquid crystal layer is 2 to 100 layers, and the birefringence coefficient is 0.01 to 0.9. The spiral number of the cholesteric liquid crystal of the second liquid crystal layer is 2-100 layers, and the birefringence coefficient is 0.01-0.9. Therefore, the cholesteric liquid crystal-based reflective device of this embodiment can reflect light in a wide spectral range.
Optionally, in this embodiment, the cholesteric liquid crystal-based reflective device further includes a mechanical structure for assisting the mounting and several electronic devices for assisting the circuit. The first liquid crystal element 220 and the second liquid crystal element 230 are disposed on the mechanical structure. The electronic device is electrically connected to at least one of the first liquid crystal element 220 and the second liquid crystal element 230 directly or indirectly.
For example, the mechanical structure may include a frame or a framework for fixing and supporting the reflection device, and a fixing connector may be provided on the frame or the framework for mounting to a wall surface or a window of an automobile, so as to be applied to a building wall surface as an outer glass wall or a window of an automobile. Further illustratively, the electronic device may include a power supply, a transformer, a switch, and the like, wherein the power supply supplies power, the power supply transforms the power to a target operating voltage through the transformer and supplies power to the reflective device, and the switch may be used to switch the power supply between the power supply and the reflective device, so that a user can switch the reflective device between the reflective state and the transparent state through the switch. The mechanical structure and the related technical content and principle of the electronic device refer to the related art in the field, and are not described in detail herein.
Example two
Referring to fig. 3, in the first embodiment, the cholesteric liquid crystal-based reflective device further includes a reflective layer 360, and the reflective layer 360 is disposed on a side of the second liquid crystal element 330 away from the first liquid crystal element 320. The second liquid crystal element 330 is further used for providing the second incident light of the remaining wavelength band to the reflective layer 360. The reflective layer 360 is configured to receive the second incident light and reflect a target reflection light 314 in a third target wavelength band, where the target reflection light 314 is emitted outwards after passing through the second liquid crystal element 330 and the first liquid crystal element 320 in sequence. The target reflected light 314 is complementary color light of the first reflected polarized light 312 and the second reflected polarized light 313.
It is understood that the cholesteric liquid crystals in the first and second liquid crystal elements 320 and 330 have different pitches, and thus, the first and second liquid crystal elements 320 and 330 respectively reflect light of wavelengths corresponding to the pitches in the planar texture state. In order to further expand the width of the reflection waveband, the cholesteric liquid crystal device is further provided with a reflection layer 360 to generate target reflection light 314 according to second incident light, and complementary colors are formed between the target reflection light 314 and the first reflection polarized light 312 and the second reflection polarized light 313, so that the reflection spectrum range of the reflection device is further increased, and the mirror effect is favorably improved. Illustratively, when the reflected light of the first liquid crystal element 320 and the second liquid crystal element 330 is deflected to the red wavelength band, the reflective layer 360 is disposed such that the reflected light is deflected to the blue wavelength band; when the reflected light of the first liquid crystal element 320 and the second liquid crystal element 330 is biased to the blue wavelength band, the reflective layer 360 is configured such that the reflected light is biased to the red wavelength band, and the light reflected by the first liquid crystal element, the second liquid crystal element 330, and the reflective layer 360 are mixed together to form white light, so as to provide a good mirror effect.
EXAMPLE III
The present embodiment provides a reflective device based on cholesteric liquid crystal, and based on the first embodiment or the second embodiment, the first liquid crystal layer includes a first cholesteric liquid crystal polymer network or first cholesteric liquid crystal polymer droplets, and the second liquid crystal layer includes a second cholesteric liquid crystal polymer network or second cholesteric liquid crystal polymer droplets.
Referring to fig. 4, the first liquid crystal layer 412 illustratively includes a first cholesteric liquid crystal polymer network 414, and the second liquid crystal layer 422 includes a second cholesteric liquid crystal polymer network 424.
Referring to fig. 5, also illustratively, the first liquid crystal layer 512 includes first cholesteric liquid crystal polymer droplets 514, and the second liquid crystal layer 522 includes second cholesteric liquid crystal polymer droplets 524.
It is understood that the liquid crystal layer further includes a polymer, and the polymer is mixed with the liquid crystal mixture and forms a correspondingly stable liquid crystal structure after being irradiated by ultraviolet rays or polymerized thermally. Depending on the size of the polymer doping concentration, a high molecular cholesteric liquid crystal polymer network can be formed, and cholesteric liquid crystal polymer droplets can also be formed. When cholesteric polymer droplets are formed, the individual polymer droplets are separated using an additionally polymerized high molecular material. The droplets or network of polymer formed cause the cholesteric liquid crystal to change from a liquid state to a semi-solid or gel state. The liquid crystal element is more convenient and simpler to mount and use.
Example four
Referring to fig. 6, on the basis of one of the first, second and third embodiments, a first separating structure 614 is disposed between the first transparent substrate 611 and the second transparent substrate 613, the first separating structure 614 is respectively connected to the first transparent substrate 611 and the second transparent substrate 613, and the first separating structure 614 is used for separating the first liquid crystal layer 612 into a plurality of first liquid crystal cells. A second partition structure 624 is disposed between the third transparent substrate 621 and the fourth transparent substrate 623, the second partition structure 624 is respectively connected to the third transparent substrate 621 and the fourth transparent substrate 623, and the second partition structure 624 is used for partitioning the second liquid crystal layer 622 into a plurality of second liquid crystal cells.
It can be understood that the liquid crystal element of the present embodiment is provided with the partition structure, which not only divides the corresponding liquid crystal layer into a plurality of liquid crystal cells, but also facilitates the combination with the upper and lower transparent substrates to form a firm and stable liquid crystal structure. When the flexible plastic substrate is adopted, the separation structure provides stable support for the substrate on one hand, and on the other hand, the contact short circuit between the electrodes is avoided, so that the insulating property is improved. In this embodiment, the partition structure is a partition wall, and in other embodiments, the partition structure may be a honeycomb or other irregular shape, and the like, which is not limited herein. Illustratively, the separation structure may be formed using a polymer.
EXAMPLE five
Referring to fig. 3, on the basis of one of the first, second, third and fourth embodiments, the cholesteric liquid crystal-based reflective device further includes a first driver 340 and a second driver 350. The first driver 340 is electrically connected to the first transparent substrate 321 and the second transparent substrate 323, respectively, and the first driver 340 is configured to drive the first liquid crystal element 320 to be in a transparent state or a reflective state; the second driver 350 is electrically connected to the third transparent substrate 331 and the fourth transparent substrate 333, respectively, and the second driver 350 is configured to drive the second liquid crystal element 330 to be in a transparent state or a reflective state.
Specifically, the first driver 340 is connected to the first electrode and the second electrode of the first liquid crystal element 320, and the second driver 350 is connected to the third electrode and the fourth electrode of the second liquid crystal element 330. The driver is used for providing different driving voltages and pulses for the corresponding liquid crystal elements, so that the corresponding liquid crystal elements are switched between a transparent state and a reflecting state. Specifically, when the driving voltage provided by the driver exceeds a preset voltage threshold, the cholesteric liquid crystal of the liquid crystal element is in a despiralized state, and the despiralized state has no effect on left-handed polarized light and right-handed polarized light and is in a transparent state. After the driver removes the driving voltage, the cholesteric liquid crystal enters a planar texture state or a focal conic texture state depending on whether the pulse form corresponding to the driving voltage is removed slowly or rapidly. If the liquid crystal enters a planar texture state, the corresponding liquid crystal element will reflect light of a particular wavelength and a particular polarization. If the liquid crystal enters the focal conic texture state, the corresponding liquid crystal element only has a weak scattering effect on the incident light, and can also be regarded as a transparent state or a scattering state.
In other embodiments, the first liquid crystal element and the second liquid crystal element may be driven simultaneously by a single driver having a superior function.
Example six
In addition to any one of the first, second, third and fourth embodiments, the cholesteric liquid crystal of the first liquid crystal element and the cholesteric liquid crystal of the second liquid crystal element are respectively configured with pitches that reflect visible light of different wavelengths.
Among all the wavelengths of reflected light, the cholesteric liquid crystal-based reflecting device reflects visible light (400 nm to 700 nm) and can be applied to decoration, partitions, smart mirrors, and the like. Exemplarily, if the helical period of the cholesteric liquid crystal is set to reflect visible light, the reflective device will modulate between reflecting visible light and transmitting visible light. When visible light is reflected, the device plays a role of a common reflector and protects privacy; when visible light is transmitted, it functions as a common transparent glass.
EXAMPLE seven
In addition to any one of the first, second, third and fourth embodiments, the cholesteric liquid crystal of the first liquid crystal element and the cholesteric liquid crystal of the second liquid crystal element are respectively configured with pitches that reflect infrared light of different wavelengths.
The reflecting device based on the cholesteric liquid crystal reflects the wavelength of infrared light and can be applied to adjusting the ambient temperature. The infrared band is divided into a near infrared band, a mid-infrared band, and a far infrared band. Light in different infrared bands in sunlight respectively has different effects on temperature.
Illustratively, if the period of cholesteric liquid crystal is set to reflect infrared light, the reflective device will adjust between reflecting infrared light and transmitting infrared light. When the temperature of a building or an indoor space is high, the infrared light is adjusted to be reflected, so that the infrared light in sunlight is blocked, and the effect of cooling is achieved. When the temperature is low, the infrared light is adjusted to be transmitted, and the effect of temperature rise is achieved. The reflecting device is applied to buildings or indoor spaces and can play a role in adjusting temperature.
Example eight
This embodiment provides a cholesteric liquid crystal-based reflecting device, on the basis of one of embodiments one, two, three, four, seven, eight, the cholesteric liquid crystal-based reflecting device further includes: third driver, fourth driver and temperature detector, temperature detector respectively with the third driver with the fourth driver electricity is connected, temperature detector is used for surveying ambient temperature to will survey the temperature send to the third driver with the fourth driver. The third driver is used for driving the first liquid crystal element to be in a transparent state when the detected temperature is smaller than a preset temperature threshold value, and driving the first liquid crystal element to be in a reflection state when the detected temperature is larger than or equal to the preset temperature threshold value. The fourth driver is used for driving the second liquid crystal element to be in a transparent state when the detection temperature is smaller than a preset temperature threshold value, and driving the second liquid crystal element to be in a reflective state when the detection temperature is larger than or equal to the preset temperature threshold value.
It can be understood that, in this embodiment, the temperature detector is arranged to detect the ambient temperature, and send the temperature to the third driver and the fourth driver, the driver compares the detected temperature with the preset temperature threshold, drives the corresponding liquid crystal element to be in the transparent state when the detected temperature is less than the preset temperature threshold, so as to transmit the visible light or the infrared light, and drives the corresponding liquid crystal element to be in the reflective state when the detected temperature is greater than or equal to the preset temperature threshold, so as to reflect the visible light or the infrared light, thereby adjusting the indoor temperature. Exemplarily, the first cholesteric liquid crystal element and the second cholesteric liquid crystal element in this embodiment may be used for reflecting infrared light at the same time, or one of the liquid crystal elements may reflect infrared light and the other liquid crystal element reflects visible light. When the indoor temperature is too high, the liquid crystal element is in a reflection state, and infrared light which can generate a heat effect and has higher heat radiation is reflected, so that the indoor temperature does not rise any more; when the indoor temperature is low, the liquid crystal element is in a transparent state, so that infrared light is emitted into the room, and the indoor temperature is increased.
Example nine
This embodiment provides a reflective device based on cholesteric liquid crystal, which uses temperature sensitive cholesteric liquid crystal based on one of the first, second, third, fourth, seventh and eighth embodiments, wherein the helical period of the temperature sensitive cholesteric liquid crystal changes with the temperature.
Specifically, the cholesteric liquid crystal of the first liquid crystal element and/or the cholesteric liquid crystal of the second liquid crystal element is a temperature-sensitive cholesteric liquid crystal. The liquid crystal element provided with the temperature sensitive cholesteric liquid crystal is used for reflecting infrared light when the ambient temperature is higher than the target temperature range and transmitting the infrared light when the ambient temperature is lower than the target temperature range, so that the function of automatically adjusting the indoor temperature is achieved. .
The first liquid crystal layer and the second liquid crystal layer may both adopt temperature-sensitive cholesteric liquid crystals, or only one of the liquid crystal layers may adopt temperature-sensitive cholesteric liquid crystals.
It can be understood that, when the ambient temperature is lower than the target temperature range, the helical period (helical pitch) of the temperature sensitive cholesteric liquid crystal in the liquid crystal layer does not correspond to the reflected infrared light, and the external infrared light enters the room, so that the room temperature rises.
Along with the gradual rise of the ambient temperature, the spiral period of the temperature sensitive cholesteric liquid crystal also changes correspondingly, until the ambient temperature is higher than the target temperature range, the spiral period of the temperature sensitive cholesteric liquid crystal correspondingly reflects infrared light, and when the liquid crystal layer is in a planar texture state, the liquid crystal layer reflects the infrared light, so that the indoor temperature does not rise any more. The reflecting device based on cholesteric liquid crystal in the embodiment adopts temperature-sensitive cholesteric liquid crystal, and can also realize indoor temperature regulation and control of ambient light.
EXAMPLE ten
The present embodiment provides a cholesteric liquid crystal-based reflective device including at least two liquid crystal elements stacked, the cholesteric liquid crystal of each of the liquid crystal elements being respectively provided with pitches that reflect light of different wavelengths. The liquid crystal element is in a reflective state when the cholesteric liquid crystal of the liquid crystal element is in a planar texture state, and is used for reflecting light with corresponding wavelength, and is in a transparent state when the cholesteric liquid crystal of the liquid crystal element is in a focal conic texture state or a despiral state.
The present embodiment uses a plurality of liquid crystal elements, each having a different pitch, which, in the reflective state, can reflect several different wavelengths of light, thereby allowing the reflective device to achieve a wider reflection range.
The reflective device in this embodiment may adopt all or part of the structures in the above embodiments, and exemplarily, a reflective layer is provided at the light exit of the liquid crystal element in the last layer, a driver is independently configured for each layer of liquid crystal element, and a partition structure is provided for each layer of liquid crystal element, which is not limited herein.
In summary, the reflective device based on cholesteric liquid crystal provided by the invention can provide two different reflected polarized lights without arranging a polarizer, and the wave band of the reflected light is increased due to the addition of the liquid crystal element, which is beneficial to improving the adjustment capability of the reflective device to indoor environment light. The reflecting device is additionally provided with a reflecting layer, so that the mirror surface effect is further improved. The liquid crystal layer comprises a cholesteric liquid crystal polymer network or cholesteric liquid crystal polymer network liquid drops and is provided with a separation structure, so that the liquid crystal structure is more stable and firmer. The cholesteric liquid crystal has a large spiral number range and a large birefringence coefficient range, so that a large reflection coefficient can be obtained, and meanwhile, a cholesteric liquid crystal structure of a reflector can reflect light rays in a wide spectrum range.
In addition, the cholesteric liquid crystal of the reflecting device is provided with a corresponding screw pitch for reflecting infrared light, and when the cholesteric liquid crystal is applied to buildings or indoor spaces, the indoor environment temperature can be adjusted; the cholesteric liquid crystal of the reflective device is provided with a corresponding pitch reflecting visible light, can exhibit a mirror effect in the reflective state, and acts as transparent glass in the transparent state. The liquid crystal element of the reflecting device can also adopt temperature sensitive cholesteric liquid crystal, can also play a role in regulating the indoor temperature, and is favorable for further improving the regulating capacity of indoor ambient light.
The application provides another kind of reflecting device based on cholesteric liquid crystal, through adopting at least two liquid crystal components that set up in a layer upon layer, the cholesteric liquid crystal of each said liquid crystal component is configured with the pitch that reflects the light of different wavelength respectively, can reflect the light of several different wavelengths, thus make the reflecting device obtain wider reflection range.
The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent modifications made by the present invention and the contents of the accompanying drawings, which are directly or indirectly applied to the related technical fields, are included in the scope of the present invention.

Claims (15)

1. A cholesteric liquid crystal-based reflective device, comprising: a first liquid crystal element and a second liquid crystal element which are stacked in this order;
the cholesteric liquid crystal in the first liquid crystal element and the cholesteric liquid crystal in the second liquid crystal element are respectively set to different chirality and helical pitch;
the first liquid crystal element and the second liquid crystal element are in a reflection state when the cholesteric liquid crystal of the first liquid crystal element and the second liquid crystal element is in a planar texture state and are in a transparent state when the cholesteric liquid crystal of the first liquid crystal element and the second liquid crystal element is in a focal conic texture state or a despiral state;
the first liquid crystal element is used for receiving initial incident light, reflecting first reflection polarized light with a first target wavelength when the first liquid crystal element is in a reflection state, and providing the first incident light with a residual waveband for the second liquid crystal element;
the second liquid crystal element receives the first incident light and reflects second reflection polarized light with a second target wavelength when the second liquid crystal element is in a reflection state, and the second reflection polarized light is emitted outwards after passing through the first liquid crystal element.
2. A cholesteric liquid crystal-based reflective device according to claim 1, wherein said cholesteric liquid crystal has three states: a focal conic texture state that effects scattering of light; a planar texture state that effects reflection of light; a despiralized state which achieves transmission of light.
3. A cholesteric liquid crystal-based reflective device according to claim 1, further comprising a reflective layer disposed on a side of the second liquid crystal element remote from the first liquid crystal element;
the second liquid crystal element is also used for providing a second incident light with a residual wave band to the reflecting layer;
the reflecting layer is used for receiving the second incident light and reflecting target reflected light of a third target waveband, and the target reflected light is emitted outwards after sequentially passing through the second liquid crystal element and the first liquid crystal element;
the target reflected light is complementary light of the first reflected polarized light and the second reflected polarized light.
4. A cholesteric liquid crystal-based reflecting device according to claim 1, wherein the first liquid crystal element comprises a first light-transmitting substrate, a first liquid crystal layer, and a second light-transmitting substrate, which are sequentially stacked;
the second liquid crystal element comprises a third light-transmitting substrate, a second liquid crystal layer and a fourth light-transmitting substrate which are sequentially stacked.
5. A cholesteric liquid crystal-based reflective device according to claim 4, wherein said first light-transmissive substrate comprises a first electrode and a first alignment layer, and said second light-transmissive substrate comprises a second electrode and a second alignment layer;
the first electrode, the first alignment layer, the first liquid crystal layer, the second alignment layer, and the second electrode are sequentially stacked;
the third light-transmitting substrate comprises a third electrode and a third alignment layer, and the fourth light-transmitting substrate comprises a fourth electrode and a fourth alignment layer;
the third electrode, the third alignment layer, the second liquid crystal layer, the fourth alignment layer, and the fourth electrode are sequentially stacked.
6. A cholesteric liquid crystal-based reflective device according to claim 4, wherein said first liquid crystal layer comprises a first cholesteric liquid crystal polymer network or first cholesteric liquid crystal polymer droplets and said second liquid crystal layer comprises a second cholesteric liquid crystal polymer network or second cholesteric liquid crystal polymer droplets.
7. A cholesteric liquid crystal-based reflecting device according to claim 4, wherein the number of helices of cholesteric liquid crystal of the first liquid crystal layer is 2 to 100 layers, and the birefringence index is 0.01 to 0.9;
the spiral number of the cholesteric liquid crystal of the second liquid crystal layer is 2-100 layers, and the birefringence coefficient is 0.01-0.9.
8. A cholesteric liquid crystal-based reflecting device according to claim 4, wherein a first separating structure is disposed between the first and second transparent substrates, the first separating structure being connected to the first and second transparent substrates, respectively, the first separating structure serving to separate the first liquid crystal layer into a plurality of first liquid crystal cells;
and a second partition structure is arranged between the third light-transmitting substrate and the fourth light-transmitting substrate, the second partition structure is respectively connected with the third light-transmitting substrate and the fourth light-transmitting substrate, and the second partition structure is used for partitioning a second liquid crystal layer into a plurality of second liquid crystal units.
9. A cholesteric liquid crystal-based reflective device according to claim 4, further comprising a first driver and a second driver;
the first driver is electrically connected with the first light-transmitting substrate and the second light-transmitting substrate respectively, and the first driver is used for driving the first liquid crystal element to be in a transparent state or a reflective state;
the second driver is electrically connected with the third transparent substrate and the fourth transparent substrate respectively, and the second driver is used for driving the second liquid crystal element to be in a transparent state or a reflective state.
10. A cholesteric liquid crystal-based reflective device according to claim 1, wherein the cholesteric liquid crystal of the first liquid crystal element and the cholesteric liquid crystal of the second liquid crystal element are respectively configured with helical pitches reflecting visible light of different wavelengths.
11. A cholesteric liquid crystal-based reflective device according to claim 1, wherein the cholesteric liquid crystal of the first liquid crystal element and the cholesteric liquid crystal of the second liquid crystal element are respectively provided with helical pitches reflecting infrared light of different wavelengths.
12. A reflective device based on cholesteric liquid crystal according to any one of claims 1-8, 10 or 11, further comprising: the temperature detector is electrically connected with the third driver and the fourth driver respectively and is used for detecting the ambient temperature and sending the detected temperature to the third driver and the fourth driver;
the third driver is used for driving the first liquid crystal element to be in a transparent state when the detected temperature is smaller than a preset temperature threshold value and driving the first liquid crystal element to be in a reflecting state when the detected temperature is larger than or equal to the preset temperature threshold value;
the fourth driver is used for driving the second liquid crystal element to be in a transparent state when the detection temperature is smaller than a preset temperature threshold value, and driving the second liquid crystal element to be in a reflective state when the detection temperature is larger than or equal to the preset temperature threshold value.
13. A reflective device according to any of claims 1-8, 10, 11, wherein the cholesteric liquid crystal of said first liquid crystal element and/or the cholesteric liquid crystal of said second liquid crystal element is a temperature sensitive cholesteric liquid crystal;
the liquid crystal element provided with the temperature-sensitive cholesteric liquid crystal is used for reflecting infrared light when the ambient temperature is higher than the target temperature range and transmitting infrared light when the ambient temperature is lower than the target temperature range.
14. A cholesteric liquid crystal-based reflective device according to any one of claims 1 to 11, further comprising a mechanical structure for auxiliary mounting and several electronic devices for auxiliary circuitry;
the first liquid crystal element and the second liquid crystal element are arranged on the mechanical structure;
the electronic device is electrically connected to at least one of the first liquid crystal element and the second liquid crystal element directly or indirectly.
15. A reflecting device based on cholesteric liquid crystal, characterized by comprising at least two liquid crystal elements which are arranged in a stacked manner, the cholesteric liquid crystal of each liquid crystal element being respectively provided with helical pitches which reflect light of different wavelengths;
the liquid crystal element is in a reflective state when the cholesteric liquid crystal of the liquid crystal element is in a planar texture state, and is used for reflecting light with corresponding wavelength, and is in a transparent state when the cholesteric liquid crystal of the liquid crystal element is in a focal conic texture state or a despiral state.
CN202211012876.9A 2022-08-23 2022-08-23 Reflecting device based on cholesteric liquid crystal Pending CN115236905A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024103607A1 (en) * 2022-11-14 2024-05-23 武汉华星光电技术有限公司 Display device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024103607A1 (en) * 2022-11-14 2024-05-23 武汉华星光电技术有限公司 Display device

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