Liquid crystal device with adjustable transmittance and reflectivity and control method

Abstract

The invention provides a liquid crystal device with adjustable transmittance and reflectivity and a control method. The device comprises a transmittance adjustable module, a light beam direction control module and a driving voltage control device, the transmissivity adjustable module sequentially comprises a first glass substrate, a first transparent conductive layer, a first orientation layer, a middle liquid crystal layer, a second orientation layer, a second transparent conductive layer and a second glass substrate from bottom to top. And the device can be switched into a transmission type working state and a reflection type working state in an electric control manner, so that the transmissivity and the reflectivity of the light beam can be adjusted in an optical system. The liquid crystal optoelectronic device with the adjustable transmittance and reflectivity can achieve electric control dynamic adjustment according to actual application requirements, and has the advantages of being simple in structure, small in size, capable of being driven through direct-current voltage, rapid in response, low in preparation cost and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal optoelectronic devices, and in particular to a liquid crystal-based optoelectronic device with adjustable transmittance and reflectance. Background Art

[0002] The flexoelectric effect of liquid crystal refers to the polarization of liquid crystal molecules caused by the bending or bending of liquid crystal molecules. The electric field also interacts with the polarization of the liquid crystal, thereby affecting the deformation of the liquid crystal molecules. The flexoelectric effect is common in liquid crystal materials, especially in some banana-shaped or wedge-shaped liquid crystals with permanent dipole moments. The flexoelectric effect causes changes in the liquid crystal director. When driven by low frequency or DC voltage, the distribution of the liquid crystal director becomes uneven, which leads to changes in light intensity transmittance. This type of liquid crystal with a large flexoelectric effect has important applications in 3D liquid crystal displays, flexoelectric optics, smart windows, sensors, and biomaterials.

[0003] Currently, optical filters, attenuators, electrochromic glass, and electro-optic modulators are used to adjust light intensity transmittance. Traditional light intensity modulators, such as filters and attenuators, have fixed transmittance, limiting their practical applications. They typically require multiple components, making them incapable of meeting the variable transmittance requirements of optical paths. Electrochromic glass can flexibly adjust light intensity by varying the applied voltage, but this requires a high-frequency voltage and can only adjust transmittance in one direction, lacking the ability to adjust transmissivity or reflectivity. Electro-optic modulators adjust transmittance by changing the material's refractive index via an applied voltage. These devices offer advantages such as fast response speed and high modulation accuracy, making them suitable for high-frequency modulation. However, they are relatively expensive and require complex drive circuits. Liquid crystal optoelectronic devices with adjustable transmittance and reflectivity, leveraging the flexoelectric effect of liquid crystals, can flexibly and accurately control light intensity transmittance at low DC or low-frequency voltages, and can also switch between transmissive and reflective modes according to actual needs. Transmittance- and reflectivity-adjustable devices fabricated using liquid crystals can further reduce the complexity of optical systems, expand their scope of application, and lower production costs. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a liquid crystal-based transmittance and reflectance tunable optoelectronic device to solve the problems of complex device structure, inflexible adjustment and small scope of application in current technology.

[0005] In order to achieve the above-mentioned purpose of the invention, the technical solution of the present invention is as follows:

[0006] A liquid crystal device with adjustable transmittance and reflectance, comprising a transmittance adjustable module 1, a light beam direction control module 2, and a driving voltage control device 3;

[0007] The transmittance adjustable module 1 includes, from bottom to top, a first glass substrate 4, a first transparent conductive layer 5, a first orientation layer 6, an intermediate liquid crystal layer 7, a second orientation layer 8, a second transparent conductive layer 9, and a second glass substrate 10. The first transparent conductive layer 5 is a transparent conductive film coated on the upper surface of the first glass substrate 4, and the second transparent conductive layer 9 is a transparent conductive film coated on the bottom of the second glass substrate 10.

[0008] The incident light passes through the adjustable transmittance module 1, and the light intensity is modulated and then emitted to the beam direction control module 2. The beam direction control module 2 switches the liquid crystal optoelectronic device between the transmission and reflection states. The driving voltage control device 3 outputs two voltage parameters to regulate the adjustable transmittance module 1 and the beam direction control module 2 respectively, thereby realizing the adjustment of the transmittance or reflectance of the incident light.

[0009] As a preferred embodiment, the conductive material of the first transparent conductive layer 5 and the second transparent conductive layer 9 is selected from one of indium tin oxide ITO, graphene, metal nanowires, carbon nanotubes, conductive polymers, silver, copper and aluminum thin films.

[0010] As a preferred embodiment, the materials of the first alignment layer 6 and the second alignment layer 8 are rubbing alignment agents or photo-alignment agents.

[0011] As a preferred embodiment, the beam direction control module 2 includes, from bottom to top, a third glass substrate 11, an electrolyte layer 13 and a fourth glass substrate 15. The third glass substrate 11 and the fourth glass substrate 15 are respectively plated with a third electrode layer 12 and a fourth electrode layer 14.

[0012] As a preferred embodiment, the conductive material of the third electrode layer 12 and the fourth electrode layer 14 is selected from one of indium tin oxide ITO, graphene, metal nanowires, carbon nanotubes, conductive polymers, silver, copper and aluminum films; and / or the material of the electrolyte layer 13 is composed of metal inorganic salts of organic solvents, ionic liquids IL and polymers.

[0013] As a preferred embodiment, the metal in the metal inorganic salt in the electrolyte layer 13 material is selected from one or more combinations of silver, gold, copper, and nickel metals; the ions in the electrolyte layer material are selected from one or more combinations of chloride ions, bromide ions, and iodide ions; the ionic liquid in the electrolyte layer material is one of quaternary ammonium salts, quaternary phosphate salts, imidazole salts, and pyridinium salts.

[0014] As a preferred method, the driving voltage control device 3 changes the degree of ion reaction by controlling the voltage loaded on the electrolyte layer 13 of the beam direction control module 2, thereby regulating the transmission or reflection of the incident light, corresponding to the two working states of the device, namely transmission and reflection.

[0015] As a preferred embodiment, the driving voltage control device 3 controls the voltage loaded on the third electrode layer 12 and the fourth electrode layer 14 of the beam direction control layer 2 to control the liquid crystal director orientation of the liquid crystal layer, and the loaded driving voltage is a DC voltage or a low-frequency voltage of 0 to 100 Hz.

[0016] As a preferred method, when there is no external electric field, the liquid crystal material of the intermediate liquid crystal layer 7 has uniform arrangement of liquid crystal molecules, and the light intensity transmittance reaches the maximum at this time; after the external electric field is applied, the flexoelectric effect interacts with the external electric field, and the pointing vectors of the liquid crystal molecules change, causing the liquid crystal to exhibit an uneven state. After the light beam is incident, the intensity of the outgoing light will change due to the scattering effect, and as the applied voltage increases, it gradually becomes opaque, thereby achieving the purpose of regulating the transmittance.

[0017] A second object of the present invention is to provide a control method for an optoelectronic device with adjustable transmittance and reflectance, based on the aforementioned liquid crystal device with adjustable transmittance and reflectance: the control method is to input corresponding voltage parameters into a driving voltage control device based on the actual required light intensity transmittance and transmissive or reflective operating state, using experimentally measured device driving voltage and transmittance curves, and then adjust the transmittance adjustable module 1 and the light beam direction control module 2 to switch between the transmission and reflection states, thereby achieving control of the transmittance and reflectance of the incident light;

[0018] The driving voltage control device 3 changes the degree of ion reaction by controlling the voltage loaded on the electrolyte layer 13 of the beam direction control module 2, thereby regulating the transmission or reflection of the incident light, corresponding to the two working states of the device, namely transmission and reflection.

[0019] The beneficial technical effects of the present invention include: applying different drive voltages through a control device to modulate the intensity of an incident light beam, and electrically switching the device between transmissive and reflective operating states, thereby adjusting the transmittance and reflectance of the light beam in an optical system. The present invention's liquid crystal optoelectronic device with adjustable transmittance and reflectivity can be electrically and dynamically adjusted according to actual application requirements, and has the advantages of a simple structure, compact size, DC voltage drive, fast response, and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of the liquid crystal-based transmittance-reflectivity-adjustable optoelectronic device of the present invention.

[0021] Figure 2 The figure is a schematic diagram of the structure of the liquid crystal layer with adjustable transmittance and reflectance of the liquid crystal-based optoelectronic device with adjustable transmittance and reflectance of the present invention.

[0022] Figure 3 Schematic diagram of the structure of the light beam direction control layer of the liquid crystal based transmittance and reflectance tunable optoelectronic device of the present invention.

[0023] Figure 4 The figure is a schematic diagram of the working light path of the liquid crystal based transmittance and reflectance tunable optoelectronic device of the present invention when the working state is transmissive.

[0024] Figure 5 The figure is a schematic diagram of the working light path of the liquid crystal based transmittance and reflectance tunable optoelectronic device of the present invention when the working state is reflective.

[0025] Figure 6 Schematic diagram of the working light path of the liquid crystal based transmittance and reflectance tunable optoelectronic device of the present invention.

[0026] Description of the accompanying figures:

[0027] 1-Transmittance adjustable module, 2-Beam direction control module, 3-Driving voltage control device, 4-First glass substrate, 5-First transparent conductive layer, 6-First orientation layer, 7-Intermediate liquid crystal layer, 8-Second orientation layer, 9-Second transparent conductive layer, 10-Second glass substrate, 11-Third glass substrate, 12-Third electrode layer, 13-Electrolyte layer, 14-Fourth electrode layer, 15-Fourth glass substrate, 16-Light source. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0029] Example 1

[0030] This embodiment provides a liquid crystal device with adjustable transmittance and reflectivity, such as Figure 1 As shown, it includes a transmittance adjustable module 1, a beam direction control module 2, and a driving voltage control device 3;

[0031] like Figure 2 As shown, the transmittance adjustable module 1 includes, from bottom to top, a first glass substrate 4, a first transparent conductive layer 5, a first orientation layer 6, an intermediate liquid crystal layer 7, a second orientation layer 8, a second transparent conductive layer 9, and a second glass substrate 10. The first transparent conductive layer 5 is a transparent conductive film coated on the upper surface of the first glass substrate 4, and the second transparent conductive layer 9 is a transparent conductive film coated on the bottom of the second glass substrate 10.

[0032] The incident light passes through the adjustable transmittance module 1, and the light intensity is modulated and then emitted to the beam direction control module 2. The beam direction control module 2 switches the liquid crystal optoelectronic device between the transmission and reflection states. The driving voltage control device 3 outputs two voltage parameters to regulate the adjustable transmittance module 1 and the beam direction control module 2 respectively, thereby realizing the adjustment of the transmittance and reflectivity of the incident light.

[0033] Preferably, the conductive material of the first transparent conductive layer 5 and the second transparent conductive layer 9 is selected from one of indium tin oxide ITO, graphene, metal nanowires, carbon nanotubes, conductive polymers, silver, copper and aluminum thin films.

[0034] Preferably, the first alignment layer 6 and the second alignment layer 8 are vertical alignment layers, and the alignment material is a rubbing alignment agent or a photo-alignment agent; the liquid crystal layer uses liquid crystal materials such as CB7CB, CB9CB, etc. with a large flexural resistivity.

[0035] like Figure 3 As shown, the beam direction control module 2 includes a third glass substrate 11, an electrolyte layer 13 and a fourth glass substrate 15 from bottom to top. The third glass substrate 11 and the fourth glass substrate 15 are respectively coated with a third electrode layer 12 and a fourth electrode layer 14.

[0036] Preferably, the conductive material of the third electrode layer 12 and the fourth electrode layer 14 is selected from one of indium tin oxide ITO, graphene, metal nanowires, carbon nanotubes, conductive polymers, silver, copper and aluminum films; the material of the electrolyte layer 13 is composed of metal inorganic salts of organic solvents, ionic liquids IL and polymers.

[0037] Preferably, the metal in the metal inorganic salt in the electrolyte layer 13 material is selected from one or more combinations of silver, gold, copper, and nickel metals; the ions in the electrolyte layer material are selected from one or more combinations of chloride ions, bromide ions, and iodide ions; the ionic liquid in the electrolyte layer material is one of quaternary ammonium salts, quaternary phosphonium salts, imidazole salts, and pyridinium salts.

[0038] Preferably, the driving voltage control device 3 changes the degree of ion reaction by controlling the voltage loaded on the electrolyte layer 13 of the beam direction control module 2, thereby regulating the transmission or reflection of the incident light, corresponding to the two working states of the device, namely transmission and reflection.

[0039] Preferably, the driving voltage control device 3 controls the voltage loaded on the third electrode layer 12 and the fourth electrode layer 14 of the beam direction control layer 2 to control the molecular orientation of the liquid crystal layer, and the loaded driving voltage is a DC voltage or a low-frequency voltage of 0 to 100 Hz.

[0040] In this example, when the voltage applied to the transmittance adjustable module by the device driving voltage control device is lower than the threshold voltage, the liquid crystal molecules do not deflect, and are evenly distributed under the constraints of the boundary conditions, and the light intensity transmittance is maximum. When the loaded voltage exceeds the threshold, the deflection and distribution of the liquid crystal molecules are asymmetric due to the interaction between the flexoelectric effect and the electric field. The orientation of the liquid crystal molecules will change with the applied voltage, showing an uneven state. At this time, the light beam passing through the transmittance control module will be scattered, thereby reducing the intensity of the outgoing light. According to the selected voltage amplitude, the corresponding outgoing light transmittance can be obtained to achieve intensity modulation of the light beam. After the loaded voltage increases to a certain value, the scattering of the light beam reaches its maximum. At this time, the light cannot pass through the transmittance adjustable module, and the transmittance is 0. The corresponding voltage and light intensity transmittance curve can be obtained.

[0041] This embodiment also provides a control method for an optoelectronic device with adjustable transmittance and reflectance. Based on the aforementioned liquid crystal device with adjustable transmittance and reflectance, the control method is to input corresponding voltage parameters into a driving voltage control device based on the actual required transmittance and transflective operating state, using experimentally measured device driving voltage and transmittance curves, and thereby adjust the transmittance adjustable module 1 and the light beam direction control module 2 to switch between the transmission and reflection states, thereby achieving control of the transmittance and reflectance of the incident light.

[0042] The driving voltage control device 3 changes the degree of ion reaction by controlling the voltage loaded on the electrolyte layer 13 of the beam direction control module 2, thereby regulating the transmission or reflection of the incident light, corresponding to the two working states of the device, namely transmission and reflection.

[0043] In this example, the voltage control device is driven to output voltage parameters to the beam direction control module, so that the device works in the transmission state, such as Figure 4 As shown in the figure, the light beam emitted by light source 16 passes through the transmittance adjustable module, driving the voltage control device to output another voltage parameter to control the transmittance adjustable module, thereby modulating the intensity of the incident light beam. The modulated light continues to be incident on the beam direction control module, and the light passing through the beam direction control module is fully transmitted. In this case, the liquid crystal device acts as a transmittance adjustment device, enabling electronically controlled adjustment of the light beam transmittance.

[0044] Preferably, in the optical system of the present invention, the centers of the light source, the transmittance adjustable module and the beam direction control module are on the same straight line, and the transmittance adjustable module and the beam direction control module are bonded together to reduce the device volume.

[0045] Example 2

[0046] This example provides a liquid crystal-based optoelectronic device with adjustable reflectivity. The device includes a light source 16, a transmittance-adjustable module 1, a beam direction control module 2, and a drive voltage control device 3. The light beam emitted by the light source passes through the transmittance-adjustable module, where its intensity is modulated and then emitted to the beam direction control module. The beam direction control module switches the liquid crystal optoelectronic device between transmission and reflection states. The drive voltage control device outputs two voltage parameters to regulate the transmittance-adjustable module and the beam direction control module, respectively, thereby adjusting the transmittance and reflectivity of the incident light.

[0047] Preferably, the transparent conductive material is selected from the group consisting of indium tin oxide (ITO), graphene, metal nanowires, carbon nanotubes, conductive polymers, silver, copper, and aluminum films. The liquid crystal layer is selected from liquid crystals such as CB7CB and CB9CB, which have a large flexural resistivity. The first and second alignment layers 6 and 8 are formed using a rubbing or photo-alignment agent, and the alignment layers are vertical alignment layers.

[0048] In this example, the voltage parameters outputted from the driving voltage control device to the beam control module are adjusted so that the device operates in a reflective state, such as Figure 5 As shown. The light beam emitted by the light source passes through the transmittance adjustable module, and the driving voltage control device outputs another voltage parameter to control the transmittance adjustable module, thereby modulating the intensity of the incident light beam. The voltage is DC or low-frequency voltage (0-100Hz). The modulated light continues to be incident on the light beam direction control module. In the reflection state, the light beam direction control module is equivalent to a mirror, and the light beam is completely reflected. The reflected light will pass through the transmittance adjustable module again and modulate the output intensity of the light beam again. According to another corresponding voltage and reflectivity curve measured experimentally, the corresponding reflectivity can be obtained by driving the voltage control device to output different voltage amplitudes. At this time, the liquid crystal device is used as a reflectivity adjustment device, which can realize the electrical control adjustment of the light beam reflectivity.

[0049] Example 3

[0050] This example provides a liquid crystal-based optoelectronic device with adjustable transmittance and reflectance. Based on Example 1, this example adds a chiral agent to the nematic liquid crystal material to create a cholesteric liquid crystal. The chiral agent is selected from CB15, S1011, S811, R2011, or R5011. The device includes a light source 16, a transmittance adjustable module 1, a beam direction control module 2, and a drive voltage control device 3. Figure 6 Shown is a schematic diagram of the device's working optical path.

[0051] Based on the experimentally measured voltage-transmittance and voltage-reflectance curves, the corresponding transmittance and reflectance can be obtained by adjusting the output voltage parameter of the driving voltage control device. Another output voltage parameter can be used to control the beam control module, making the device operate in a transmission or reflection state, thus achieving electronic control of the transmittance or reflectance of the light beam.

[0052] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A liquid crystal device with adjustable transmittance and reflectance, characterized in that: It comprises a transmittance adjustable module (1), a light beam direction control module (2), and a driving voltage control device (3); The transmittance adjustable module (1) comprises, from bottom to top, a first glass substrate (4), a first transparent conductive layer (5), a first orientation layer (6), an intermediate liquid crystal layer (7), a second orientation layer (8), a second transparent conductive layer (9), and a second glass substrate (10); the first transparent conductive layer (5) is a transparent conductive film plated on the upper surface of the first glass substrate (4); and the second transparent conductive layer (9) is a transparent conductive film plated on the bottom of the second glass substrate (10); Incident light passes through the transmittance adjustable module (1), and after light intensity is modulated, it is emitted to the light beam direction control module (2). The light beam direction control module (2) switches the liquid crystal optoelectronic device between the transmission state and the reflection state. The driving voltage control device (3) respectively regulates the transmittance adjustable module (1) and the light beam direction control module (2) by outputting two voltage parameters, thereby achieving adjustment of the transmittance or reflectance of the incident light.

2. The liquid crystal device with adjustable transmittance and reflectance according to claim 1, wherein: The conductive material of the first transparent conductive layer (5) and the second transparent conductive layer (9) is selected from one of indium tin oxide (ITO), graphene, metal nanowires, carbon nanotubes, conductive polymers, silver, copper and aluminum thin films.

3. The liquid crystal device with adjustable transmittance and reflectance according to claim 1, wherein: The materials of the first orientation layer (6) and the second orientation layer (8) are rubbing orientation agents or photo-orientation agents.

4. The liquid crystal device with adjustable transmittance and reflectance according to claim 1, wherein: The light beam direction control module (2) comprises, from bottom to top, a third glass substrate (11), an electrolyte layer (13), and a fourth glass substrate (15); the third glass substrate (11) and the fourth glass substrate (15) are respectively plated with a third electrode layer (12) and a fourth electrode layer (14).

5. The liquid crystal device with adjustable transmittance and reflectance according to claim 4, characterized in that: The conductive materials of the third electrode layer (12) and the fourth electrode layer (14) are selected from one of indium tin oxide (ITO), graphene, metal nanowires, carbon nanotubes, conductive polymers, silver, copper and aluminum films; and / or the material of the electrolyte layer (13) is composed of metal inorganic salts of organic solvents, ionic liquids (IL) and polymers.

6. The liquid crystal device with adjustable transmittance and reflectance according to claim 5, characterized in that: The metal in the metal inorganic salt in the electrolyte layer (13) material is selected from one or more combinations of silver, gold, copper, and nickel metals; the ions in the electrolyte layer material are selected from one or more combinations of chloride ions, bromide ions, and iodide ions; and the ionic liquid in the electrolyte layer material is one of quaternary ammonium salts, quaternary phosphonium salts, imidazole salts, and pyridinium salts.

7. The liquid crystal device with adjustable transmittance and reflectance according to claim 1, wherein: The driving voltage control device (3) changes the degree of ion reaction by controlling the voltage loaded on the electrolyte layer (13) of the light beam direction control module (2), thereby regulating the transmission or reflection of the incident light, corresponding to the two working states of the device, namely transmission mode and reflection mode.

8. The liquid crystal device with adjustable transmittance and reflectance according to claim 1, wherein: The driving voltage control device (3) controls the voltage applied to the third electrode layer (12) and the fourth electrode layer (14) of the light beam direction control layer (2) to control the liquid crystal director orientation of the liquid crystal layer, and the applied driving voltage is a DC voltage or a low-frequency voltage of 0 to 100 Hz.

9. The liquid crystal device with adjustable transmittance and reflectance according to claim 1, wherein: When the liquid crystal material of the intermediate liquid crystal layer (7) is free from an external electric field, the liquid crystal molecules are arranged uniformly, and the light intensity transmittance reaches a maximum at this time; when an external electric field is applied, the flexoelectric effect interacts with the external electric field, and the director vector of the liquid crystal molecules changes, so that the liquid crystal exhibits an uneven state. After the light beam is incident, the intensity of the outgoing light changes due to the scattering effect, and as the applied voltage increases, it gradually becomes an opaque state, thereby achieving the purpose of regulating the transmittance.

10. A control method for an optoelectronic device with adjustable transmittance and reflectance, based on the liquid crystal device with adjustable transmittance and reflectance according to any one of claims 1 to 9, characterized in that: The control method is to input corresponding voltage parameters into the driving voltage control device according to the actual required light intensity transmittance, transmission type or reflection type working state, and the device driving voltage and transmittance curve measured by experiment, thereby adjusting the transmission and reflection states of the transmittance adjustable module (1) and the light beam direction control module (2), thereby realizing the control of the transmittance and reflectance of the incident light; The driving voltage control device (3) changes the degree of ion reaction by controlling the voltage loaded on the electrolyte layer (13) of the light beam direction control module (2), thereby regulating the transmission or reflection of the incident light, corresponding to the two working states of the device, namely transmission mode and reflection mode.

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