CN211454165U - Variable-focus liquid crystal lens with arc-shaped columnar cavity and electrodes - Google Patents

Abstract

The utility model discloses a variable-focus liquid crystal lens with an arc-shaped columnar cavity and an electrode, which mainly comprises a protective shell, a driving module, an upper electrode, a lower electrode, a liquid crystal alignment layer and a liquid crystal arranged in the protective shell. After the liquid crystal is perfused in the present invention, the liquid crystal molecules inside can be uniformly distributed according to the uniform arc-shaped column filling space, and then the liquid crystal molecules are oriented and arranged in the direction required by the experimental research through the orientation effect, which will make the liquid crystal molecules oriented and arranged in the direction required by the experimental research. When the electric field is applied, the liquid crystal molecules will have a certain deflection angle. In this way, when a larger range of zooming needs to be performed in the future, the liquid crystal molecules need to be rotated to a larger angle by applying an external voltage. Increasing the angle on the basis of the liquid crystal molecules with a certain deflection angle will cause the voltage of the applied external electric field to be relatively high. Lower, that is to say, compared with the parallel plate zoom liquid crystal lens, the voltage required to be applied to the horizontal liquid crystal molecules to rotate through the same degree is larger than that of the present invention.

Description

A variable-focus liquid crystal lens with arc-shaped cylindrical cavity and electrodes

technical field

The utility model relates to the field of liquid crystal lenses, in particular to an arc-shaped columnar cavity structure and a focal length variable liquid crystal lens with arc-shaped columnar electrodes laid along the arc-shaped columnar cavity.

Background technique

With the continuous development of science and technology and the continuous deepening of research, people's work research and many fields of daily life also have more and higher requirements for lenses, especially adjustable focal length lenses.

As is known to all, the focal length of a conventional lens is fixed in a single unit, so a conventional zoom system is composed of a plurality of lenses of a single focal length with different focal lengths, and needs to be mechanically adjusted. Such a zoom system has many disadvantages, such as complex structure, cumbersome operation and high operation requirements, complex production process and high cost. What is even more unsatisfactory is that its focusing range is limited and cannot meet the focusing requirements of many jobs. It limits its development and application to a certain extent. The emergence of electronically controlled zoom liquid crystal lenses has largely solved many problems of traditional zoom lenses or zoom systems. The electronically controlled zoom liquid crystal lens utilizes the electro-optical effect of liquid crystal (electrically controlled birefringence effect), that is, by applying an electric field to change the arrangement direction of the liquid crystal molecules, the refractive index ne of the corresponding extraordinary light is continuously changed to the refractive index no of ordinary light. The orientation of the liquid crystal molecules in the box is controlled by the voltage, the refractive index is changed, and the focal length is adjusted accordingly, so as to achieve the purpose of realizing the function of the lens. Specifically, because liquid crystal has crystal anisotropy, that is, when a beam of light passes through the liquid crystal layer, it will be divided into two beams of light with different polarization directions: o light and e light, where o light is ordinary light, and e light is extraordinary light . When the o light propagates in the liquid crystal, no matter which direction it faces, the refractive index is fixed, and the e light is just opposite to the o light, and its vibration direction is always perpendicular to the o light, so it will be different when it propagates in different directions. the index of refraction. Because of this, when an electric field is applied to the liquid crystal, since the directors of some liquid crystal molecules tend to be oriented along the direction of the electric field, with the change of the voltage, the deflection angle of the directors of the liquid crystal molecules will also change accordingly. The equivalent index of refraction will be different, so that a gradient index of refraction can be formed. When the polarized light is incident, the polarized light will form a convergence or divergence effect. It is because of the combination of these characteristics that the liquid crystal lens has the function of electronically controlled zoom. Simply put, the liquid crystal molecules are turned under the action of the electric field, so that the polarized light passing through the lens is refracted to achieve the focusing effect, and the electronically controlled zoom is realized. The zoom range can be controlled by the voltage. The specific working principle is shown in Figure 5. Show. This also makes the structure of the zoom lens simpler and smaller, the production is simple and the cost is low, the zooming is flexible and the zooming steps are many, making the zooming more convenient, accurate and delicate. This also makes the electronically controlled zoom liquid crystal lens quickly become a research hotspot, and then has a wide range and rich application, and has successively replaced the traditional zoom lens in many fields.

There are many types of zoom liquid crystal lenses developed today, and their application fields and functions are also expanding. For example, there are many zoom liquid crystal lenses in the field of scientific research: single-hole electrode type, strip electrode type, ring-disc electrode type, single and double-layer liquid crystal lenses, etc.; light field microscope liquid crystal lenses in the medical field, Endoscope liquid crystal lens, etc.; 3D display liquid crystal lens in entertainment life, naked eye 3D liquid crystal lens display device, etc. Liquid crystal lenses are widely used in many fields.

However, since some key technical problems of the liquid crystal lens have not been solved and perfected, its further application is also limited. Today, many researchers have encountered and have been improving the problems that the driving voltage of the zoom liquid crystal lens is too large, the focusing range is not large enough, and the response speed is not fast enough. Therefore, the existing technology needs to be further improved and perfected.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a zoom liquid crystal lens with lower driving voltage, faster response speed and better structure.

The purpose of the present utility model is achieved through the following technical solutions:

A variable-focus liquid crystal lens with an arc-shaped columnar cavity and an electrode mainly includes a protective shell, a driving module, an upper electrode, a lower electrode, a liquid crystal alignment layer and a liquid crystal arranged in the protective shell. The protective shell is designed with an arc-shaped arch structure, the cross section is a hollow ring, and the protective shell is also provided with a cavity for pouring liquid crystal. The upper electrode is arranged in the cavity of the protective shell, is located on the upper wall of the cavity, and is arranged along the arc of the cavity. The lower electrode is arranged in the cavity of the protective shell, is located on the lower wall of the cavity, and is arranged along the arc of the cavity. The liquid crystal alignment layer is respectively disposed on the upper electrode and the lower electrode, and is fixedly connected with the upper electrode and the lower electrode. The liquid crystal fills the cavity in the protective shell; the output ends of the driving module are respectively electrically connected to the upper electrode and the lower electrode.

Further, the lower electrode is also provided with a circular hole for generating an uneven electric field, and the circular hole is arranged at the center of the lower electrode.

As a preferred solution of the present invention, the protective shell is made of glass material with high light transmittance.

As a preferred solution of the present invention, the liquid crystal is a nematic liquid crystal.

As a preferred solution of the present invention, both the upper electrode and the lower electrode are circular electrodes made of transparent indium zinc oxide material.

The working process and principle of the utility model are as follows: the utility model is based on the existing flat-panel liquid crystal lens, and the shape of the liquid crystal poured inside the liquid crystal cell is made into a uniform arc by bending a conventional cuboid along a certain direction with a certain amplitude. After the liquid crystal is perfused, the liquid crystal molecules inside can be uniformly distributed according to the uniform arc-shaped column filling space, and then the liquid crystal molecules are aligned in the direction required by the experimental research through the orientation effect, which will make the When the electric field is applied, the liquid crystal molecules will have a certain deflection angle. In this way, when a larger range of zooming needs to be performed in the future, the liquid crystal molecules need to be rotated by an external voltage to a larger angle, and increasing the angle on the basis of the liquid crystal molecules with a certain deflection angle will make the voltage of the applied external electric field relatively Lower, that is to say, compared with the parallel-plate zoom liquid crystal lens, the voltage required to be applied to the horizontal liquid crystal molecules to rotate through the same degree is larger than that of the present invention. Further, this relatively improves the response speed of the zoom lens. At the same time, the conventional plate-circular hole electrodes are changed to arc-circular hole electrodes laid along the upper and lower outer walls of the arc-shaped cylindrical cavity, which can further reduce the overall volume of the lens and make the liquid crystal lens further miniaturized.

Compared with the prior art, the utility model also has the following advantages:

(1) The variable-focus liquid crystal lens of the arc-shaped columnar cavity and the electrode provided by the utility model adopts a uniform arc-shaped columnar filled liquid crystal lens, which can be further turned by applying a driving voltage on the basis that the liquid crystal molecules have a certain angle, so that the liquid crystal molecules can be turned. When it reaches the same angle as the flat liquid crystal zoom lens molecule rotates, the driving voltage is lower, so that the response speed of the lens will be improved accordingly.

(2) Compared with the conventional flat-panel liquid crystal lens, the variable-focus liquid crystal lens with the arc-shaped columnar cavity and electrodes provided by the present utility model is equivalent to a preprocessing of a deflection angle on the liquid crystal molecules, so that it can be The driving voltage is reduced, and the response speed of the liquid crystal lens will also be improved; at the same time, it is equivalent to some concave liquid crystal lenses or convex liquid crystal lenses, which can solve the uneven distribution of liquid crystal molecules in the middle and both ends of the concave and convex liquid crystal lenses. It is more conducive to the transmission and focusing of light, and can also reduce or eliminate problems such as poor focusing effect, imaging distortion and dispersion caused by uneven distribution of liquid crystals. The change of the electrodes can also make the overall volume of the lens more miniaturized.

(3) The variable-focus liquid crystal lens with the arc-shaped columnar cavity and the electrodes provided by the present invention is simple in structure in terms of production, and the electrode design, liquid crystal perfusion, box sealing and other technical means can directly use the existing mature methods and means in the past, Many problems have been solved for the manufacture of lenses.

Description of drawings

1 is a schematic cross-sectional view of a variable-focus liquid crystal lens with an arc-shaped cylindrical cavity and electrodes provided by the present invention.

FIG. 2 is a cross-sectional view of a variable-focus liquid crystal lens with an arc-shaped cylindrical cavity and electrodes provided by the present invention.

3 is a schematic diagram of the refractive index ellipsoid of liquid crystal molecules provided by the present invention.

4 is a schematic diagram of the degree of refraction of light before and after the application of a voltage to the variable-focus liquid crystal lens with an arc-shaped cylindrical cavity and an electrode provided by the present invention.

FIG. 5 is a schematic diagram showing the degree of refraction of light before and after applying a voltage to a conventional flat/flat liquid crystal lens.

Description of the symbols in the above drawings:

1-upper electrode, 2-lower electrode, 3-liquid crystal alignment layer, 4-protective shell, 5-liquid crystal, 6-driving module, 7-round hole.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present utility model clearer and clearer, the present utility model will be further described below with reference to the accompanying drawings and examples.

Example 1:

As shown in FIG. 1 to FIG. 4 , the present embodiment discloses a variable-focus liquid crystal lens with an arc-shaped cylindrical cavity and an electrode, which mainly includes a protective shell 4 , a driving module 6 , and an upper electrode 1 disposed in the protective shell 4 . , the lower electrode 2 , the liquid crystal alignment layer 3 and the liquid crystal 5 . The protective shell 4 is designed with an arc-shaped arch structure, and the cross section is a hollow annular shape. The protective shell 4 is also provided with a cavity for pouring the liquid crystal 5 . The upper electrode 1 is arranged in the cavity of the protective shell 4, on the upper wall of the cavity, and is arranged along the arc of the cavity. The lower electrode 2 is arranged in the cavity of the protective shell 4, is located on the lower wall of the cavity, and is arranged along the arc of the cavity. The liquid crystal alignment layer 3 is respectively disposed on the upper electrode 1 and the lower electrode 2 , and is fixedly connected with the upper electrode 1 and the lower electrode 2 . The liquid crystal 5 fills the cavity in the protective shell 4 ; the output ends of the driving module 6 are electrically connected to the upper electrode 1 and the lower electrode 2 respectively.

Further, the lower electrode 2 is also provided with a circular hole 7 for generating a non-uniform electric field, and the circular hole 7 is arranged at the center of the lower electrode 2 .

As a preferred solution of the present invention, the protective shell 4 is made of glass material with high light transmittance.

As a preferred solution of the present invention, the liquid crystal 5 is a nematic liquid crystal.

As a preferred solution of the present invention, both the upper electrode 1 and the lower electrode 2 are circular electrodes made of transparent indium zinc oxide material.

The working process and principle of the present utility model are as follows: the present utility model, on the basis of the existing flat-panel liquid crystal lens, makes the shape of the liquid crystal 5 poured inside the liquid crystal cell into a uniform shape by bending a conventional cuboid along a certain direction with a certain amplitude. Arc columnar, after filling the liquid crystal 5, the liquid crystal 5 molecules inside can be evenly distributed according to the uniform arc columnar filling space, and then the liquid crystal 5 molecules are aligned in the direction required by the experimental research through the orientation effect, which will make When no external electric field is applied, the molecules of the liquid crystal 5 will have a certain deflection angle. In this way, when a larger range of zoom needs to be performed in the follow-up, the liquid crystal 5 molecules need to be rotated by an external voltage to a larger angle. On the basis of the liquid crystal 5 molecules with a certain deflection angle, increasing the angle will cause the voltage of the external electric field to be applied. It will be relatively reduced, that is to say, compared with the parallel plate zoom liquid crystal lens, the voltage required to be applied to the horizontal liquid crystal 5 molecules to rotate the same degree is larger than that of the present invention. Further, this relatively improves the response speed of the zoom lens. At the same time, the conventional plate-circular hole 7 electrodes are changed to arc-circular hole 7 electrodes laid along the upper and lower outer walls of the arc-shaped cylindrical cavity, which can further reduce the overall volume of the lens and make the liquid crystal lens further miniaturized.

Example 2:

The purpose of this embodiment is to provide a variable-focus liquid crystal lens, the interior of which is arc-shaped columnar and filled with liquid crystal 5, so that the molecules of the liquid crystal 5 already have a certain deflection angle when no electric field is applied, so that the molecules of the liquid crystal 5 have a certain deflection angle after the electric field is subsequently applied. The steering provides a larger angle, which can also reduce the driving voltage and improve the response speed of the liquid crystal lens to a certain extent. At the same time, the laying method of the electrodes is changed to arc cylindrical circular holes 7 electrodes, so as to achieve the effect of reducing the volume of the liquid crystal lens.

The technical scheme adopted in this embodiment is as follows:

A variable-focus liquid crystal lens, the lens comprises: an upper electrode 1, a lower electrode 2, an upper and lower PI layer (a liquid crystal alignment layer 3), a glass protective shell 4, a nematic liquid crystal 5, an external voltage drive and a bottom lower electrode 2 Center electrode round hole 7.

Wherein, the upper electrode 1 is a transparent ITO (Indium tin oxide, indium zinc oxide) circular electrode that can be patterned according to needs. ITO has excellent properties such as strong electrical conductivity and high transmittance. It has high transparency to visible light, and its transmittance is above 80%. It is especially suitable for conductive electrodes of liquid crystal lenses; the lower electrode 2 is commonly used. , A circular hole 7ITO circular electrode that can provide the required electric field; the alignment layer is a PI (Polyimide, polyimide) alignment layer laid along the spherical liquid crystal 5 filling cavity, which can make the liquid crystal 5 molecules follow the arc-shaped columnar hollow. The cavities or the actual desired directions are aligned. The orientations of the molecules of the eigenstate liquid crystal 5 are chaotic and different, so it is necessary to add an orientation layer on the surface of the liquid crystal layer to make the initial orientation of the liquid crystal 5 molecules uniform. When no driving voltage is applied, the arrangement of the directors of the liquid crystal 5 molecules will tend to the predetermined direction, so that the initial free energy is minimized. After adding the external driving voltage, the directors of the liquid crystal 5 molecules will turn with the applied electric field. The anchoring force on the surface of the liquid crystal 5 molecules is balanced with the action of the applied electric field to keep the overall free energy of the liquid crystal 5 to a minimum, so as to provide help for the subsequent voltage to change the deflection angle of the liquid crystal 5 molecules; the glass protective shell 4 includes the entire cylindrical lens outside along the arc The glass protective shell 4 made of the cylindrical cavity has a very high light transmittance of the glass material, which can protect the liquid crystal 5 and regulate the shape of the entire lens without causing great interference to the incident light; The liquid crystal 5 is a common nematic liquid crystal with stable performance; the voltage drive provides a zoom voltage for the lens, which is connected to the upper electrode 1 and the lower electrode 2, and can be connected to an external driving circuit through the electrodes. Different voltages for changing the focal length of the lens are provided; the central electrode circular hole 7 of the bottom lower electrode 2 is a circular hole 7 opened at the center of the lower electrode 2, which corresponds to the circular hole 7 in the lower electrode 2 of a traditional flat lens. The cross-sectional view and the three-dimensional view of the structure of the liquid crystal 5 zoom lens are shown in FIGS. 1 and 2 , FIG. 3 is a schematic diagram of the liquid crystal 5 molecular refractive index ellipsoid principle, and FIG. 4 is a schematic diagram of the working principle of the liquid crystal lens of the present invention.

The phenomenon of polarized light refraction and focusing after the light of the present invention enters the liquid crystal 5 can be explained by the refractive index ellipsoid of the liquid crystal 5: As shown in FIG. A material with excellent optoelectronic properties, the liquid crystal 5 molecules have the property of changing the arrangement mode with the change of the electric field. Therefore, the liquid crystal zoom lens mainly uses the non-uniform electric field generated by the electrode of the round hole 7 to make a gradient change in the alignment and deflection angle of the liquid crystal 5 molecules, so that the refractive index of the liquid crystal 5 molecules changes gradiently, showing a refractive index gradient distribution similar to that of a lens. . Figure 3 is a schematic diagram of the refractive index ellipsoid of the liquid crystal 5 molecules. When light is incident on the liquid crystal 5 molecules in different directions, the refractive indices are different. In other words, when the deflection angle of the liquid crystal 5 molecules changes, the light After entering the liquid crystal 5, the obtained refractive indices are different. When the polarization direction of the incident light is parallel to the long axis direction of the liquid crystal 5 molecule, the refractive index is n _e ; when the polarization direction of the incident light is perpendicular to the long axis direction of the liquid crystal 5 molecule, the refractive index is n _o . When the angle between the direction and the long axis of the liquid crystal 5 molecule is θ, the refractive index is n _eff (θ), and its expression is as follows:

where: n _o ≤n _eff (θ)≤n _e , n _e represents the refractive index when the polarization direction of the incident light is parallel to the long axis direction of the liquid crystal 5 molecule; n _o represents the polarization direction of the incident light is perpendicular to the liquid crystal 5 The refractive index in the direction of the long axis of the molecule; θ represents the angle between the polarization direction of the incident light and the long axis of the liquid crystal 5 molecule.

It can be seen from the above that the working schematic diagram of the liquid crystal zoom lens of the present invention is shown in FIG. 4 .

The utility model uses the arc-shaped columnar liquid crystal 5 to fill the cavity design, and then uses the PI alignment layer to make the liquid crystal 5 molecules align and arrange according to the shape of the arc-shaped columnar cavity, so that the liquid crystal 5 molecules have a certain angle in the initial state. In other words, the liquid crystal 5 molecules are preprocessed, so that the initial state of the entire liquid crystal lens is equivalent to the state of the liquid crystal 5 molecules rotated by a certain angle when a certain voltage is applied to the flat liquid crystal lens. The actual working state of the liquid crystal zoom lens is the principle. As shown in Fig. 4: When no voltage is applied, the liquid crystal zoom lens is pretreated due to the arc-shaped cylindrical hollow shell, so when a beam of polarized light enters the liquid crystal lens, due to the initial deflection angle of the liquid crystal 5 molecules, the In the initial state, there will be a focusing effect; when an external voltage is applied, it can further deflect the preprocessed liquid crystal 5 molecules, so as to achieve a further zooming effect on the basis of the initial focusing, so it can be significantly reduced The driving voltage and response speed of the liquid crystal lens. The preprocessing angle can be changed according to the lens and actual needs, but the preprocessing angle should not be too large. If the preprocessing angle is too large, the focusing range of the entire lens will be severely reduced, which will greatly affect the focusing function of the liquid crystal lens. and practicality. Because the pretreatment angle is too large, the deflection angle of the liquid crystal 5 molecules in the liquid crystal lens is directly large, so the rotation angle space of the liquid crystal 5 molecules controlled by the voltage is reduced, and the range of adjustable focus is also reduced. .

The above-mentioned embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited by the above-mentioned embodiments, and any other changes, modifications, and substitutions made without departing from the spirit and principle of the present utility model , combination and simplification, all should be equivalent replacement methods, which are all included in the protection scope of the present invention.

Claims (5)

1. a variable-focus liquid crystal lens of an arc-shaped columnar cavity and an electrode, characterized in that, comprising a protective casing, a drive module, and an upper electrode, a lower electrode, a liquid crystal alignment layer and a liquid crystal arranged in the protective casing; the protection The shell is designed with an arc-shaped arch structure, the cross section is a hollow ring, and the protective shell is also provided with a cavity for pouring liquid crystal; the upper electrode is arranged in the cavity of the protective shell and is located on the upper wall of the cavity, and arranged along the arc shape of the cavity; the lower electrode is arranged in the cavity of the protective shell, located on the lower wall of the cavity, and arranged along the arc shape of the cavity; the liquid crystal alignment layer is respectively arranged on the upper electrode and the lower electrode , which is fixedly connected with the upper electrode and the lower electrode; the liquid crystal fills the cavity in the protective shell; the output end of the driving module is electrically connected with the upper electrode and the lower electrode respectively. 2 . The variable-focus liquid crystal lens with an arc-shaped cylindrical cavity and an electrode according to claim 1 , wherein the lower electrode is further provided with a circular hole for generating an uneven electric field, and the circular hole is arranged in the lower electrode. 3 . at the center. 3 . The variable-focus liquid crystal lens with an arc-shaped cylindrical cavity and an electrode according to claim 1 , wherein the protective shell is made of a glass material with high light transmittance. 4 . 4 . The variable-focus liquid crystal lens with arc-shaped columnar cavity and electrodes according to claim 1 , wherein the liquid crystal is a nematic liquid crystal. 5 . 5 . The variable-focus liquid crystal lens with an arc-shaped cylindrical cavity and an electrode according to claim 1 , wherein the upper electrode and the lower electrode are circular electrodes made of transparent indium zinc oxide material. 6 .

Images