CN214846119U

CN214846119U - Point scanning patterning liquid crystal photo-alignment system

Info

Publication number: CN214846119U
Application number: CN202023188555.3U
Authority: CN
Inventors: 刘泉; 王蓓; 李文杰
Original assignee: Kunshan Jiyang Photoelectric Technology Co ltd
Current assignee: Kunshan Jiyang Photoelectric Technology Co ltd
Priority date: 2020-12-26
Filing date: 2020-12-26
Publication date: 2021-11-23
Anticipated expiration: 2030-12-26

Abstract

The utility model discloses a point scanning patterning liquid crystal photo-alignment system, which comprises a light source module, an optical shaping and micro-subsystem, an imaging detection component, a power detection subsystem, a focusing detection and correction subsystem, a polarization state modulation subsystem and a motion control subsystem which are connected in sequence; the utility model discloses realize in every region can both be with interference pattern accurate focusing projection on the photosensitive material surface and then high quality face pattern design liquid crystal photo-orientation by a wide margin, and have the advantage that the light efficiency utilization ratio is high, polarization state regulation and control is accurate and linear.

Description

Point scanning patterning liquid crystal photo-alignment system

Technical Field

The utility model relates to a liquid crystal orientation arranges the control field, especially relates to a point scanning patterning liquid crystal photo-alignment system.

Background

Liquid crystals have wide applications in the fields of information display, optics, photonics devices and the like; the liquid crystal can further realize the modulation of amplitude, phase and polarization of light according to the designed orientation arrangement, and plays an important role in the applications, so the orientation arrangement control mode of the liquid crystal becomes a research hotspot of academic and industrial production, and the prior art disclosed at present mainly comprises a rubbing orientation technology and a photo-orientation technology:

photoalignment is a non-contact liquid crystal aligning method which is newly developed, and the photoalignment technology is divided into four types at present, wherein the photoalignment technology utilizes photosensitive materials to perform oriented photocrosslinking, isomerization or photocracking reaction under the irradiation of ultraviolet or blue light polarized light to obtain the required arrangement: mask overlay polarization patterning techniques, periodic liquid crystal alignment techniques obtained by holographic interference methods, dynamic mask photo-alignment techniques based on DMDs, and also polarization alignment techniques based on spatial modulators.

The polarization orientation technology based on the liquid crystal spatial modulator is a programmable control device capable of modulating the phase and amplitude of incident light, and pattern recording of different orientation arrangements of liquid crystals in different selected areas can be realized by single projection orientation.

Patent application No. CN201820881217.1 discloses a photo-alignment apparatus for realizing arbitrary distribution by one exposure, which introduces a photo-alignment method for single exposure using a pixelated electrically controlled phase delay device, wherein the phase delay of each pixel of the pixelated electrically controlled phase delay device is controlled by a corresponding voltage respectively for generating the phase delay of arbitrary pattern distribution, but the problem of generating a phase pattern by one exposure is that the data size is proportional to the format size, which limits the format size of the prepared device, and also considers that a high-precision high-resolution photo-alignment pattern cannot be generated.

Foreign beam corporation has provided an apparatus and method for photoalignment by irradiating LCOS phase modulation devices with continuous laser light (De Sio L, Roberts D E, Liao Z, et al, digital polarization altering geographic phase Optics [ J ] Optics express,2016,24(16):18297 18306.), they have adopted low-energy continuous laser light to expose, considering the information amount of the image and the properties of exposure uniformity, material heat capacity, thermal diffusion, etc., tens of seconds to tens of minutes are required for exposure to a single field of view, and the exposure breadth is limited by the image information and cannot photoalign a large area breadth.

Patent No. 2012102250939 discloses a DMD-based photo-alignment technique for realizing a dynamic mask function by controlling the deflection of micromirrors in a DMD, which can realize the alignment arrangement of liquid crystal selection regions without replacing the mask, but cannot realize the recording of random alignment patterns in the liquid crystal selection regions in a single photo-alignment process, and can only realize the recording of single-direction polarization patterns in each photo-alignment operation, and if the recording of different-direction polarization patterns in different selection regions is to be realized, a plurality of design drawings are required to be drawn and continuously and repeatedly loaded on a DMD control chip to realize the alignment of different selection regions, and the polarizer needs to be rotated once to control the polarization direction of light every loading, resulting in low production efficiency and mechanical rotation error.

Therefore, a new device and method for outputting a polarization pattern in the field of liquid crystal display is desired.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems of the prior art, on the one hand, the utility model discloses a point scanning patterning liquid crystal photo-alignment system, which comprises a light source module, an optical shaping and micro-system, an imaging detection component, a power detection subsystem, a focusing detection and correction subsystem, a polarization state modulation subsystem and a motion control subsystem which are connected in sequence;

the light source module is used for providing a laser light source and modulating light emitted by the laser light source into uniform polarized light;

the polarization state modulation subsystem is used for adjusting the polarized light of the light source module into polarized light with any angle;

the imaging detection component is used for detecting the imaging of the polarization pattern output to the workpiece;

the optical shaping and micro-shrinking system is used for shaping the light source emitted by the light source module into light spots with fixed shapes and shrinking the light spots to a specified multiplying power;

the power detection subsystem is used for detecting the change of the energy of the light source in real time;

the focus detection and correction subsystem is used for detecting the focus position of the micro light spot and adjusting the distance between the microscope objective and a platform to be exposed and loaded with light polarization sensitive materials, so that the current position of the platform is in a clear focus position of the microscope objective;

and the motion control subsystem is connected with the optical shaping and shrinking system, is used for adjusting the spatial position of the platform carrying the light polarization sensitive material, and is used for splicing the light field with the shrunk polarization pattern.

As a further improvement of the embodiment of the present invention, the light source module includes a laser light source, a light beam homogenizer, and a quarter wave plate, and the laser light source is a linearly polarized light source;

the beam dodging device is used for modulating the laser light sources in Gaussian distribution into nearly rectangular distribution; the quarter-wave plate is used for modulating the linearly polarized light source into circularly polarized light.

As a further improvement of the embodiment of the present invention, the light source module includes a laser light source, a beam homogenizer, and a polarizer, and the laser light source is an unpolarized light source; the polaroid is used for modulating unpolarized light into a single polarized light source; the light beam dodging device is used for modulating the laser light sources in Gaussian distribution into approximately rectangular distribution.

As a further improvement of the embodiment of the present invention, the optical shaping and shrinking system includes a light source shaping component and a shrinking component, wherein the light source shaping component is used for forming the laser light source into a replaceable mask with a hollow shape;

the miniature component is used for miniature polarization patterns output by the polarization state modulation subsystem and writing the polarization patterns into the light polarization sensitive material;

the miniature imaging component comprises a group of cylindrical lenses and a microscope objective lens; the cylindrical lens is in an infinite correction telecentric form, the main shaft direction of the light path of the microscope objective is perpendicular to the platform, and the motor drives the microscope objective to vertically move up and down to form a focusing surface on the platform.

As a further improvement of the embodiment of the present invention, the power detection subsystem includes a light splitting element and a power detector, the light splitting element is configured as a light splitting flat sheet or a light splitting prism; the light splitting element is used for splitting the shaped light source into two paths, one path enters the miniature part for miniature exposure, and the other path enters the power detector to record the power change of the light source.

As a further improvement of the embodiment of the present invention, the focus detection and correction subsystem includes a detection light source, a second lens, a second dichroic plate, an imaging objective lens group, a second imaging CCD, and a motor, which are connected in sequence;

the detection light source is positioned on the front focal plane of the second lens; the second light splitter is positioned on the back focal plane of the second lens; the imaging surface of the second imaging CCD is positioned on the front focal plane of the second lens; the motor drives the imaging objective lens group;

the first imaging CCD receives a reflection image projected to the light polarization sensitive material surface, and the first imaging CCD and the phase modulator form a conjugate image.

As a further improvement of the embodiment of the present invention, the imaging detection assembly includes a first light splitter, a cylindrical lens, an imaging objective lens group, a first lens, and a first imaging CCD, which are connected in sequence;

the front focal plane of the imaging objective group is positioned on the rear focal plane of the tube mirror; the imaging surface of the first imaging CCD is positioned on the front focal plane of the first lens; the back focal plane of the first lens is positioned on the front focal plane of the tube mirror.

As the utility model discloses the embodiment improves further, polarization state modulation subsystem, including polaroid and rotating electrical machines, the rotating electrical machines drive the polaroid is rotatory, and adjusts in real time according to the processing demand the angle of polaroid realizes the adjustment of arbitrary angle polarized light.

As a further improvement of the embodiment of the present invention, the motion control subsystem comprises a platform and a motion controller, wherein the motion controller is used for controlling the platform to move on a two-dimensional plane according to the user requirement, and acquiring and feeding back the real-time coordinate position and the real-time moving speed of the platform;

the platform is arranged below the microscope objective and is provided with a two-dimensional motion track which is used for bearing the light polarization sensitive material and driving the light polarization sensitive material to move on a two-dimensional plane under the drive of the motion control subsystem, so that the surface of the light polarization sensitive material is always kept on the focus plane of the microscope objective.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the utility model can realize the accurate focusing and projection of interference patterns on the surface of photosensitive materials in each area by combining the splicing technology formed by the real-time adjustable miniature objective system through the motion of the platform, and can realize the high-quality large-area patterned liquid crystal photo-orientation;

2. the utility model has the advantages of high light efficiency utilization rate, and the diffraction efficiency of the spatial light modulator is less than 40% by adopting a spatial light modulator system in the prior art;

3. the utility model has the advantages of the polarization state regulation and control is accurate and linear, through the angle of the accurate control polaroid of rotating electrical machines, can realize the polarization state regulation and control of high accuracy, the system that adopts LCOS not only needs to rectify the gray scale, and the regulation and control linearity of polarization state is relevant with the product characteristic of LCOS itself, the linearity of different LCOS adjustments is different;

4. the utility model adopts the assistance of the focusing servo system to control the objective lens to move up and down, focus in real time and improve the resolution;

5. the utility model discloses a two-dimensional plane removes is done to high accuracy platform accurate control sample, writes for realizing the big breadth and provides the advantage.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a dot-scan patterned liquid crystal photo-alignment system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the shape and deflection angle of the diaphragm according to an embodiment of the present invention;

the examples in the figures are represented as:

1-an illumination component; 11, pulse laser; 2-a polarization state modulation subsystem; a 22-phase modulator; 3-an imaging detection component; 32-a first light splitter; 4-focus detection and correction subsystem; 42-second dichroic sheet; 5-a motion control subsystem; 6-a platform; 7-collimating polarizing component.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the following description will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The embodiment of the present invention provides a control logic specifically comprising: the control software in the industrial personal computer transmits the position data to the motion control module, the motion control module converts the received data into a control signal and transmits the control signal to the motor driver, and the motor driver controls the motion of the motor according to the received control signal; the detection device is responsible for monitoring the motion of the motor in real time and sending the motion position and the motion speed of the motor to the motion control module; and the motion control module feeds back the current position and speed of the platform to the software.

The utility model discloses the photo-alignment method of midpoint scanning patterning liquid crystal photo-alignment system includes following steps:

s1, after being shaped by a light beam homogenizer, the light beam with Gaussian distribution emitted by the laser source is modulated into parallel uniform polarized light;

s2, modulating the polarized light into polarized light with any angle;

s3, the light splitting sheet transmits the polarized light to the imaging detection assembly to detect the imaging of the polarization pattern output to the workpiece;

s4, adjusting the distance between the imaging objective lens group and the light polarization sensitive material surface by the focusing detection and correction subsystem, so that the focal plane of the imaging objective lens group is always kept at the light polarization sensitive material surface;

s5, recording the single light control orientation on the light polarization sensitive material;

and S6, moving the platform carrying the light polarization sensitive material to the next designated position for the next pattern light field recording.

As a further improvement of the embodiment of the present invention, after the step S2, the method further includes the following steps: the miniature imaging component forms a fixed miniature multiplying power through the ratio of the focal lengths of the cylindrical lens and the imaging objective lens group, and miniature is carried out on the output polarization pattern, so that a polarization pattern light field is output.

As a further improvement of the embodiment of the present invention, after step S6, the method further includes:

s7, stitching together each pattern light field record to form a light field of a substantially plane-polarized light pattern on the light polarization sensitive material.

As a further improvement of the embodiment of the present invention, the step S4 specifically includes the following steps:

the second lens reflects the light spots projected to the light polarization sensitive material surface to the second imaging CCD, the Z-axis servo focusing position is mapped through the light spot diameter, the vertical height of the Z-axis lens is adjusted, the light spot diameter in the second imaging CCD can be always kept to be R, and whether the light polarization sensitive material surface is on the focusing surface of the objective lens or not is judged by detecting the size of the light spots projected to the light polarization sensitive material surface through the second imaging CCD.

As a further improvement of the embodiment of the present invention, after the step S6 of recording the single polarization pattern on the light polarization sensitive material, the platform carrying the light polarization sensitive material is moved to the next designated position for the next orientation, which is specifically realized by the following steps:

the controller transmits the position data to the motion control module, the motion control module converts the received data into a control signal and transmits the control signal to the motor driver, the motor driver controls the motion of the motor according to the received control signal, and the detection device is responsible for monitoring the motion of the motor in real time and transmitting the motion position and the motion speed of the motor to the motion control module; and then the motion control module feeds back the current position and the speed of the platform to the controller.

Detailed description of the invention

The utility model discloses in the concrete example, the concrete structure of polarization state regulation subsystem is the diaphragm, and size Y that defines diaphragm scanning direction divides with scanning speed is exposure dose, and the size X of diaphragm vertical scanning direction is the width of scanning lines. Before a line of scanning exposure of the platform is started, a polarizer is controlled to rotate to a specified angle through a controller, then a laser is started, and finally a scanning axis Y of the platform is translated at a specified speed at a constant speed to form a line of exposure; moving the X axis according to the width of the scanning line; the specified angles may be selected from 0 °, 45 °, 90 °, 135 °, 180 °, 225 °, 270 °, 315 °, and 360 °;

as shown in fig. 1, the shape of the aperture is rectangular, and may be selected from any other shapes such as triangle and umbrella, and the exposure dose in the same horizontal line in each scan line is controlled by controlling the shape of the aperture.

The embodiment of the utility model provides an adopt overlap joint dislocation scanning exposure, as the example shown in figure 2, the part through step direction diaphragm overlaps scanning exposure promptly, can realize that the cycle is less than the grating of diaphragm X direction size. Exposure of any gray pattern: the correspondence between the 0-255 gray scale of the gray scale map and the polarizer angle is set, for example: gray scale 0 corresponds to a polarization angle of 0 deg., and gray scale 255 corresponds to a polarization angle of 359 deg.. And the polarization angle corresponding to the gray value G in the gray scale image is G.about. 359/255. the size of each pixel point in the gray scale image is set to be S (DPI), the coordinates of each pixel point in the gray scale image can be calculated to be X and Y, the polarization angles at corresponding positions are stored together to be a three-dimensional array file, and the X, Y and Z axis motions of the platform are controlled through a control program to be sequentially exposed. Wherein Z is the angle corresponding to the electrically adjustable rotating polarizer.

Above-mentioned all optional technical scheme can adopt arbitrary combination to form the optional embodiment of this utility model, and the repeated description is no longer given here.

It should be noted that: in the above embodiment, when the high-speed exposure patterned liquid crystal photo-alignment apparatus and system is used to perform a high-speed exposure patterned liquid crystal photo-alignment method, only the division of the functional modules is taken as an example, and in practical applications, the above function distribution may be completed by different functional modules according to needs, that is, the internal structure of the system may be divided into different functional modules to complete all or part of the above-described functions. In addition, the embodiments of the high-speed exposure patterned liquid crystal photo-alignment device and the high-speed exposure patterned liquid crystal photo-alignment method provided by the embodiments belong to the same concept, and specific implementation processes thereof are described in the embodiments of the methods and are not described herein again.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A point scanning patterned liquid crystal photo-alignment system is characterized by comprising a light source module, an optical shaping and micro system, an imaging detection assembly, a power detection subsystem, a focusing detection and correction subsystem, a polarization state modulation subsystem and a motion control subsystem which are sequentially connected;

2. The dot-scan patterned liquid crystal photoalignment system according to claim 1, wherein the light source module comprises a laser light source, a beam homogenizer, a quarter wave plate, the laser light source being a linearly polarized light source;

3. The dot-scan patterned liquid crystal photoalignment system according to claim 1, wherein the light source module comprises a laser light source, a beam homogenizer, a polarizer, the laser light source being an unpolarized light source; the polaroid is used for modulating unpolarized light into a single polarized light source; the light beam dodging device is used for modulating the laser light sources in Gaussian distribution into approximately rectangular distribution.

4. The dot-scan patterned liquid crystal photoalignment system according to claim 1, wherein the optical shaping and shrinking system comprises a light source shaping component and a shrinking component, the light source shaping component is used for forming the laser light source into a replaceable mask with a hollow shape;

5. The spot scanning patterned liquid crystal photoalignment system of claim 4, wherein the power detection subsystem comprises a beam splitting element configured as a beam splitting plate or a beam splitting prism and a power detector; the light splitting element is used for splitting the shaped light source into two paths, one path enters the miniature part for miniature exposure, and the other path enters the power detector to record the power change of the light source.

6. The dot-scan patterned liquid crystal photoalignment system according to claim 5, wherein the imaging detection assembly comprises a first light splitter, a tube lens, an imaging objective lens group, a first lens, and a first imaging CCD, which are connected in sequence;

7. The dot-scan patterned liquid crystal photoalignment system according to claim 6, wherein the focus detection and correction subsystem comprises a detection light source, a second lens, a second dichroic plate, an imaging objective lens set, a second imaging CCD, and a motor, which are connected in sequence;

8. The dot-scan patterned liquid crystal photoalignment system according to claim 1, wherein the polarization state modulation subsystem comprises a polarizer and a rotating motor, the rotating motor drives the polarizer to rotate, and the angle of the polarizer is adjusted in real time according to processing requirements, so as to adjust polarized light of any angle.

9. The system according to claim 1, wherein the motion control subsystem comprises a platform and a motion controller, the motion controller is used for controlling the platform to move on a two-dimensional plane according to the user requirement, and acquiring and feeding back the real-time coordinate position and the real-time moving speed of the platform;