CN114690457A - Point scanning patterning liquid crystal photo-alignment system and method - Google Patents
Point scanning patterning liquid crystal photo-alignment system and method Download PDFInfo
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- CN114690457A CN114690457A CN202011569662.2A CN202011569662A CN114690457A CN 114690457 A CN114690457 A CN 114690457A CN 202011569662 A CN202011569662 A CN 202011569662A CN 114690457 A CN114690457 A CN 114690457A
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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
- G02F1/1303—Apparatus specially adapted to the manufacture of LCDs
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- G—PHYSICS
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- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
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- G—PHYSICS
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- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/02—Mountings, adjusting means, or light-tight connections, for optical elements for lenses
- G02B7/04—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification
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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
- G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
- G02F1/13378—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation
- G02F1/133788—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation by light irradiation, e.g. linearly polarised light photo-polymerisation
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Abstract
The invention discloses a point scanning patterned liquid crystal photo-alignment system, which comprises a light source module, an optical shaping and micro-subsystem, 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; the invention also discloses a point scanning patterning liquid crystal photo-orientation method; the invention can accurately focus and project interference patterns on the surface of a photosensitive material in each area so as to realize high-quality large-area patterned liquid crystal photo-orientation, and has the advantages of high light efficiency utilization rate, accurate and linear polarization state regulation and control.
Description
Technical Field
The invention relates to the field of liquid crystal orientation arrangement control, in particular to a dot scanning patterning liquid crystal photo-orientation system and a dot scanning patterning liquid crystal photo-orientation method.
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.
Disclosure of Invention
In order to solve the problems of the prior art, on one hand, the invention discloses a point scanning patterned liquid crystal photo-alignment system, which comprises a light source module, an optical shaping and micro-scaling 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 sequentially connected;
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, which carries a light polarization sensitive material, 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 miniature assembly, is used for adjusting the spatial position of the platform carrying the light polarization sensitive material, and is used for splicing the miniature polarization pattern light field.
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 quarter wave plate, wherein 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, wherein the laser light source is an unpolarized light source; the polaroid is used for modulating the 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 micro-scale subsystem includes a light source shaping component and a micro-scale 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 focusing detection and correction subsystem comprises a detection light source, a second lens, a second dichroic sheet, 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 tube 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 a further improvement of the embodiment of the present invention, the polarization state modulation subsystem includes a polarizer and a rotating motor, and the rotating motor drives the polarizer to rotate, and adjusts the angle of the polarizer in real time according to the processing requirement, so as to adjust the polarized light at any angle.
As a further improvement of the embodiment of the present invention, the motion control subsystem includes a platform and a motion controller, the motion controller is configured to control the platform to move on a two-dimensional plane according to a user requirement, and acquire and feed back a real-time coordinate position and a 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.
In another aspect, the present invention also discloses a dot scanning patterned liquid crystal photo-alignment method, comprising the 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, the step S2 is further followed by 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 the 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 implemented 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.
Compared with the prior art, the invention has the following beneficial effects:
1. according to the invention, through the movement of the platform and the combination of the splicing technology formed by the real-time adjustable miniature objective lens system, the interference pattern can be accurately focused and projected on the surface of the photosensitive material in each area, and the high-quality large-area patterned liquid crystal photo-orientation can be realized;
2. the invention has the advantage of high light efficiency utilization rate, and the diffraction efficiency of the spatial light modulator is less than 40 percent by adopting a spatial light modulator system in the prior art;
3. the invention has the advantages of accurate and linear polarization state regulation, can realize high-precision polarization state regulation and control by accurately controlling the angle of the polaroid through the rotating motor, adopts the LCOS system to correct gray scale, has the regulation and control linearity of the polarization state related to the product characteristics of the LCOS, and has different LCOS regulation linearity;
4. the invention adopts the assistance of a focusing servo system to control the objective lens to move up and down, focus in real time and improve the resolution;
5. the invention adopts the high-precision platform to accurately control the sample to do two-dimensional plane movement, and provides favorable conditions for realizing large-format writing.
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 introduced 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 based on these 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 of the diaphragm and the deflection angle in 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 technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to solve the problems of the prior art, on one hand, the invention discloses a point scanning patterned liquid crystal photo-alignment system, which comprises a light source module, an optical shaping and micro-scaling 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 sequentially connected;
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 miniature assembly, is used for adjusting the spatial position of the platform carrying the light polarization sensitive material, and is used for splicing the miniature polarization pattern light field.
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 quarter wave plate, wherein 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, wherein 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 micro-scale subsystem includes a light source shaping component and a micro-scale 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 part comprises a polarization pattern used for miniature output of the polarization state modulation subsystem and writing the polarization pattern 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 sheet, 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 tube 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 a further improvement of the embodiment of the present invention, the polarization state modulation subsystem includes a polarizer and a rotating motor, and the rotating motor drives the polarizer to rotate, and adjusts the angle of the polarizer in real time according to the processing requirement, so as to adjust the polarized light at any angle.
As a further improvement of the embodiment of the present invention, the motion control subsystem includes a platform and a motion controller, the motion controller is configured to control the platform to move on a two-dimensional plane according to a user requirement, and acquire and feed back a real-time coordinate position and a 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.
The control logic in the embodiment of the invention is specifically as follows: 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.
In another aspect, the present invention also discloses a dot scanning patterned liquid crystal photo-alignment method, comprising the 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 the 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 implemented 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
In an embodiment of the present invention, the polarization state adjustment subsystem is specifically configured as an aperture, a dimension Y of the aperture in a scanning direction divided by a scanning speed is defined as an exposure dose, and a dimension X of the aperture in a direction perpendicular to the scanning direction is defined as a width of a scanning line. 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 invention adopts lapping dislocation scanning exposure, as shown in the example of fig. 2, namely, the grating with the period smaller than the dimension of the diaphragm in the X direction can be realized through partial overlapping scanning exposure of the diaphragm in the stepping direction. 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.. The polarization angle corresponding to the gray value G in the gray scale image is G × 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 of the corresponding positions are stored together to be a three-dimensional array file, the movement of the X axis, the movement of the Y axis and the movement of the Z axis of the platform are controlled through a control program, and the sequential exposure is carried out. Wherein Z is the angle corresponding to the electrically adjustable rotating polarizer.
Compared with the prior art, the invention has the following beneficial effects:
1. according to the invention, through the movement of the platform and the combination of the splicing technology formed by the real-time adjustable miniature objective lens system, the interference pattern can be accurately focused and projected on the surface of the photosensitive material in each area, and the high-quality large-area patterned liquid crystal photo-orientation can be realized;
2. the invention has the advantage of high light efficiency utilization rate, and the diffraction efficiency of the spatial light modulator is less than 40 percent by adopting a spatial light modulator system in the prior art;
3. the invention has the advantages of accurate and linear polarization state regulation, can realize high-precision polarization state regulation and control by accurately controlling the angle of the polaroid through the rotating motor, adopts the LCOS system to correct gray scale, has the regulation and control linearity of the polarization state related to the product characteristics of the LCOS, and has different LCOS regulation linearity;
4. the invention adopts the assistance of a focusing servo system to control the objective lens to move up and down, focus in real time and improve the resolution;
5. the invention adopts the high-precision platform to accurately control the sample to do two-dimensional plane movement, and provides favorable conditions for realizing large-format writing.
All the above-mentioned optional technical solutions can be combined arbitrarily to form the optional embodiments of the present invention, and are not described herein again.
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 purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (13)
1. A point scanning patterned liquid crystal photo-alignment system is characterized by comprising a light source module, an optical shaping and micro-shrinking subsystem, 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;
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, which carries a light polarization sensitive material, 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 miniature assembly, is used for adjusting the spatial position of the platform carrying the light polarization sensitive material, and is used for splicing the miniature polarization pattern light field.
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;
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.
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 spot scanning patterned liquid crystal photoalignment system of claim 1, wherein the optical shaping and shrinking subsystem 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;
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 constructed in an infinite correction telecentric mode, 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 focus plane on the platform.
5. The spot scanning patterned liquid crystal photoalignment system of claim 1, 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 dividing the shaped light source into two paths, one path enters the miniature part for miniature exposure, and the other path enters the power detector for recording the power change of the light source.
6. The dot-scan patterned liquid crystal photoalignment system according to claim 5, 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;
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.
7. The dot-scan patterned liquid crystal photoalignment system according to claim 1, 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;
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.
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;
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.
10. A dot-scan patterned liquid crystal photoalignment method, comprising:
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.
11. The dot-scan patterned liquid crystal photoalignment method according to claim 10, further comprising the following steps after the step S2: the miniature imaging component forms a fixed miniature multiplying power through the ratio of focal lengths of the cylindrical lens and the imaging objective lens group, and is used for miniature the output polarization pattern so as to output a polarization pattern light field.
12. The dot-scan patterned liquid crystal photoalignment method according to claim 10, wherein the step S6 is followed by further comprising:
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.
13. The method according to claim 10, wherein the step S4 specifically comprises the steps of:
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.
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| CN202011569662.2A CN114690457A (en) | 2020-12-26 | 2020-12-26 | Point scanning patterning liquid crystal photo-alignment system and method |
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| CN202011569662.2A CN114690457A (en) | 2020-12-26 | 2020-12-26 | Point scanning patterning liquid crystal photo-alignment system and method |
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