CN211123570U - Illumination system applied to high-speed exposure patterned liquid crystal photo-alignment device - Google Patents

Abstract

The utility model discloses an illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device, comprising a pulsed light source and a collimation and polarization component, which are used for providing a light source for continuous stroboscopic exposure and realizing a single polarization collimation uniform surface light spot; The illumination system is connected to a polarization pattern generating component, and the polarization pattern generating component includes a phase modulation device; the energy per unit area of the pulsed light source is higher than the threshold energy of the light polarization sensitive material on the liquid crystal substrate, and is lower than the damage of the phase modulation device threshold. The utility model utilizes the characteristics of high pulse laser energy, short pulse width and high repetition frequency, realizes single-frame polarization pattern recording based on single or multiple pulses, and has the advantages of large area, high efficiency and good reliability.

Description

Illumination system applied to high-speed exposure patterned liquid crystal photo-alignment device

technical field

The utility model relates to the field of liquid crystal display, in particular to an illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device.

Background technique

Liquid crystals are widely used in information display, optical and photonics devices and other fields; liquid crystals can further realize the modulation of the amplitude, phase and polarization of light according to the designed alignment, and play an important role in these applications. Therefore, the alignment of liquid crystals The control method has become a research hotspot in academic and industrial production. The existing technologies currently disclosed are mainly rubbing orientation technology and light-controlled orientation technology:

Photo-controlled alignment is a newly developed non-contact liquid crystal alignment method, which utilizes directional photocrosslinking, isomerization or photolysis reaction of photosensitive materials under the irradiation of ultraviolet or blue polarized light to obtain the desired alignment. There are four types of photo-controlled alignment technologies: mask overlay polarization pattern technology, periodic liquid crystal alignment technology obtained by holographic interference, DMD-based dynamic mask photo-alignment technology, and spatial modulator-based polarization alignment technology technology.

The polarization alignment technology based on the liquid crystal spatial modulator is a programmable control device that can modulate the phase and amplitude of the incident light. A single projection alignment can realize the pattern recording of different alignments of liquid crystals in different selected areas.

Patent Application No. CN201820881217.1 discloses a photo-alignment device that realizes arbitrary distribution by one exposure. It introduces a photo-controlled alignment method using a pixelated electronically controlled phase delay device for single exposure, wherein the pixelated electronically controlled phase delay device The phase delay of each pixel is controlled separately by the corresponding voltage, which is used to generate the phase delay of any pattern distribution, but the problem of generating the phase pattern by one exposure is that the amount of data is proportional to the size of the format, which limits the prepared The size of the device is also destined to be unable to produce high-precision and high-resolution photo-alignment patterns.

Foreign beam companies have provided a device and method for photo-orientation using continuous laser irradiation of LCOS phase modulation devices (De Sio L, Roberts D E, Liao Z, et al. Digital polarization holography advancing geometrical phase optics [J]. Optics express, 2016 , 24(16):18297-18306.), they used a low-energy continuous laser for exposure, considering the amount of image information, exposure uniformity, material heat capacity, thermal diffusion and other properties, exposure to a single field of view takes tens of seconds To tens of minutes, and the exposure format is limited by image information, it is impossible to photo-orientate a large-area format.

Therefore, there is an urgent need for a new illumination system in the field of liquid crystal display that utilizes pulsed laser illumination to output polarization patterns.

Utility model content

In order to solve the problems of the prior art, the utility model discloses an illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device. The illumination system includes a pulsed light source and a collimation and polarization component, which is used to provide continuous stroboscopic exposure. The light source and the realization of a single polarization collimated uniform surface spot;

The high-speed exposure patterned liquid crystal photo-alignment device further includes a polarization pattern generating component, and the illumination system is connected to the polarization pattern generating component; the polarization pattern generating component includes a phase modulation device;

After the single or multiple pulsed beams generated by the pulsed light source have undergone the steps of beam expansion, collimation and beam splitting, at the position of the phase modulator, the cumulative energy density is lower than the damage threshold of the phase modulation device; surface, the cumulative energy density is higher than the threshold energy of the light polarization sensitive material.

The energy per unit area of the pulsed light source is higher than the threshold energy of the light polarization sensitive material on the liquid crystal substrate, and lower than the damage threshold of the phase modulation device.

As a further improvement of the embodiment of the present invention, the pulsed light source is generated by a pulsed laser or a continuous laser plus a mechanical or photoelectric light blocking plate, or a pulsed LED or a continuous LED plus a controllable light blocking plate system.

As a further improvement of the embodiment of the present invention, the pulsed light emitted by the pulsed light source passes through the collimating and polarizing component to form a collimated uniform light spot with a divergence angle of less than 10 mrad and light intensity uniformity better than 80%.

As a further improvement of the embodiment of the present invention, the repetition frequency of the pulsed light source is 1Hz to 10kHz;

The pulse width of the pulsed light source is in the order of picoseconds to seconds, and the energy of a single pulse is in the order of nanojoules to millijoules.

As a further improvement of the embodiment of the present invention, the wavelength of the pulsed light source is between 340nm and 600nm, and the half-width of the pulsed light source is less than 5nm;

In a constant temperature and humidity environment, the center wavelength drift of the pulsed light source is less than 3 nm; the half-wave width of the light source is less than 5 nm, and more than 80% of the energy of the pulsed light source is concentrated within the half-width of the center wavelength.

As a further improvement of the embodiment of the present invention, the influence of the pulsed light source on the phase delay of the output pattern of the polarization pattern generating component satisfies the following formula:

where δ is the polarization angle of a single pixel set by the phase control device;

为误差造成的位相延迟。

Phase delay due to errors.

As a further improvement of the embodiment of the present invention, the center wavelength shift of the pulsed light source, and the half-width, temperature, and wave plate errors to the polarization degree phase error of the output pattern of the polarization pattern generating component are less than 1%.

As a further improvement of the embodiment of the present invention, after the incident light of the pulsed light source is phase-modulated by the polarization pattern generating component, the intensity ratio between the polarization direction and the direction perpendicular to the polarization direction is greater than 10:1.

As a further improvement of the embodiment of the present invention, the pulsed light source is a pulsed laser, and the pulse width of the pulsed laser is less than or equal to the image maintenance time of the phase modulation device. When an image of the phase modulation device is maintained , there is at least one pulsed laser peak irradiated on the phase modulation device.

As a further improvement of the embodiment of the present invention, the lighting system further includes a collimating and polarizing component, and the collimating and polarizing component includes a collimating component and a polarizing plate;

The collimating component is used to adjust the line light source or the point light source into a parallel surface light source and output it to the polarization pattern generating component;

The polarizer is used to generate single polarized light, and the polarizer is connected to the collimating component to control the initial polarization direction of the light to generate a surface light source with any polarization direction within the range of 0-179 degrees.

In the embodiment of the present utility model, the high-speed exposure patterned liquid crystal photo-alignment device using the illumination system further includes a polarization pattern generating component, an imaging detection component, a focus servo system and a motion control component sequentially connected to the illumination system;

The polarization pattern generating component includes a quarter-wave plate and a phase modulator connected in sequence, for outputting a pixelated programmable polarization pattern to the workpiece; the phase modulator is connected with the imaging detection component; the The phase modulation device is a liquid crystal phase modulation device, which is used to load different phases for each pixel;

The imaging detection component is used for detecting the generated pattern imaging; the focus servo system includes a normally-on light source insensitive to light polarization sensitive material and a vertical direction correcting component, used for correcting the defocus phenomenon caused by motion;

The motion control part is used to adjust the spatial position of the platform carrying the light polarization sensitive material, so as to realize the light field splicing.

As a further improvement of the embodiment of the present invention, the phase modulation device is a pixel-type phase retarder with adjustable phase difference; the polarization plane light source is reflected as a light spot containing different polarization information and transmitted to the light splitting component;

The phase delay modulation of the pulse light source by the phase modulation device is greater than 2π;

The phase modulation precision of a single gray level controlled by a computer program is better than 0.01π, so as to realize any phase delay modulation within one cycle; the phase delay drift of the phase modulation device is less than 0.005π.

As a further improvement of the embodiments of the present utility model, the imaging detection assembly further includes a miniature imaging component;

The microminiature imaging component is used for microminiaturizing the polarization pattern output by the polarization pattern generating component, and writing it into the light polarization sensitive material;

The miniature imaging component includes an imaging objective lens group, the main axis of the optical path of the imaging objective lens group is perpendicular to the platform, and the motor drives the imaging objective lens group to move up and down in the vertical direction to form a focusing surface on the platform.

As a further improvement of the embodiment of the present invention, the platform is disposed below the imaging objective lens group and has a two-dimensional motion track, which is used to carry the light polarization sensitive material and drive the light polarization sensitive material to move in the direction of the light polarization sensitive material driven by the motion control component. Two-dimensional plane movement, so that the surface of the light polarization sensitive material is always kept on the focal plane of the imaging objective lens group;

The motion control part is connected with the miniature imaging part, and is used for splicing the miniature polarized pattern light field.

As a further improvement of the embodiment of the present invention, the imaging detection assembly includes a first beam splitter, a tube lens, an imaging objective lens group, a polarizer, a first lens, and a first imaging CCD connected in sequence;

The front focal plane of the imaging objective lens group is located near the back focal plane of the tube lens; the imaging plane of the first imaging CCD is located on the front focal plane of the first lens; the back focal plane of the first lens located at the front focal plane of the tube lens.

As a further improvement of the embodiment of the present invention, the focal length servo system includes a detection light source, a second lens, a second beam splitter, an imaging objective lens group, a second imaging CCD, and a motor connected in sequence;

The detection light source is located at the front focal plane of the second lens; the second beam splitter is located at the back focal plane of the second lens; the imaging plane of the second imaging CCD is located at the front focal plane of the second lens surface; the motor drives the imaging objective lens group;

The first imaging CCD receives the reflected image projected onto the surface of the light polarization sensitive material, 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 quarter-wave plate is disposed between the phase modulator and the imaging detection component;

The phase modulator is a liquid crystal spatial light modulator, a pixel-type phase retarder with adjustable phase difference δ; the polarization rotation direction is δ/2; the polarization direction of the incident light, the crystal axis direction of the phase modulation device and the four The direction of the crystal axis of the one-wave plate forms an included angle of 0, 45, and 90 degrees.

As a further improvement of the embodiment of the present invention, the polarization pattern generating component includes a first quarter-wave plate, a phase modulation device, and a second quarter-wave plate connected in sequence;

The long axis direction of the first quarter wave plate, the crystal axis direction of the phase modulation device, and the crystal axis direction of the first quarter wave plate form an included angle of 0, 45, and 90 degrees.

As a further improvement of the embodiment of the present invention, the motion control component further includes a controller and a motor drive device, and the controller is used to convert the collected optical path data into control signals and send them to each execution component;

The controller includes a motion control module, and the motion control module includes a platform motion control unit;

The motor driving device is used to drive the motor to drive the focusing platform and the platform to move, and the detection device is used to monitor the movement of the motor in real time, and send the movement position and speed of the motor to the motion control module;

The platform motion control unit is used to control the light polarization sensitive material to move in a two-dimensional plane, so as to realize the splicing of polarized light fields or the interconnection between different polarized light fields through the pattern splicing component.

As a further improvement of the embodiment of the present invention, the wavelength of the light emitted from the detection light source is any value between 550nm and 700nm;

The specified wavelength band reflection flat sheet is a reflection flat sheet coated with a wavelength reflection film of the detection light source.

In the embodiment of the present invention, the line light source or point light source emitted from the laser is adjusted to be a collimated polarized surface light source; the illumination light source is evenly irradiated on the phase modulator at a preset angle, through the quarter wave plate and the phase The modulator generates a pattern of arbitrary polarization distribution; further, a fixed miniature magnification is formed by the ratio of the focal length of the tube lens and the miniature objective lens, the polarization pattern output by the phase modulator is miniaturized, and then the polarization pattern light field is output; detection and adjustment of the miniature The distance between the objective lens and the light polarization sensitive material surface keeps the focal plane of the miniature objective always on the light polarization sensitive material surface; detect the size of the light spot projected on the light polarization sensitive material surface, and judge whether the light polarization sensitive material surface is on the focal plane of the objective lens ; Then record the single-shot light-controlled orientation onto the light-polarization-sensitive material; move the platform loaded with the light-polarization-sensitive material to the next designated position for the next pattern light field recording; splicing each orientation unit together, in the light Arbitrarily distributed light alignment structures are formed on the polarization-sensitive material.

Among them, the image reflected from the surface of the light polarization sensitive material passes through the miniature objective lens, the tube lens, the specified wavelength band reflection flat plate, and the first beam splitter in sequence, and then enters the first imaging CCD through the first lens, and the phase modulator and the first imaging CCD are located in The front focal plane of the tube lens is in a conjugate relationship. By controlling the up and down movement of the lens of the miniature objective lens, the sharpness of the image of the first imaging CCD is adjusted to determine whether the focal plane of the microscopic objective lens is on the surface of the light polarization sensitive material, and the second imaging is calibrated The size of the laser spot in the CCD is used to monitor the focus of the subsequent splicing; the contrast of the contour of the imaging spot projected onto the polarization-sensitive material is used to determine whether the focal plane of the objective lens is on the surface of the polarization-sensitive material.

In the embodiment of the present utility model, the wavelength of the light emitted by the detection light source is any value between 550 nm and 650 nm; the second lens reflects the light spot projected on the surface of the light polarization sensitive material into the second imaging CCD, and maps Z through the spot diameter Axis servo focusing position, adjust the upper and lower height of the Z-axis lens, the spot diameter in the second imaging CCD can always be kept as R, so that the second imaging CCD can detect the size of the spot projected on the light polarization sensitive material surface to judge the light Whether the polarization-sensitive material surface is in the focal plane of the objective.

Moving the platform carrying the light polarization-sensitive material to the next designated position for the next orientation is achieved through the following steps: the controller transmits the position data to the motion control module, and the motion control module converts the received data into control signals and Send it to the motor driver, 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 sends the motion position and speed of the motor to the motion control module; then the motion control module will focus on the platform And the current position and speed of the sample stage are fed back to the controller.

Specifically, after the single-shot photo-controlled orientation is recorded on the light-polarization-sensitive material, the moving distance for moving the platform carrying the light-polarization-sensitive material to the next specified position through the motion control module is the size of the single-shot alignment unit, and The movement method is to move and scan row by row.

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

1. The present utility model utilizes the pulsed illumination system to control the phase change of a single exposure area in real time when applied to high-speed exposure patterned liquid crystal photo-alignment, so as to achieve high-precision and high-resolution exposure;

2. Using the characteristics of high pulse laser energy, short pulse width and high repetition frequency, single-frame polarization pattern recording is realized based on single or multiple pulses, which has the advantages of large area, high efficiency and good reliability;

3. The light source of the present invention adopts the ultraviolet or blue light after beam expansion and collimation, adjusts the light field with a phase modulator, and can generate different polarization phases, and then combines the imaging system for miniaturization, and finally realizes polarization modulation in any direction in the unit pixel. , effectively overcome the problems of "single polarization orientation, low flexibility and low processing efficiency";

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 uses a high-precision platform to precisely control the sample to move on a two-dimensional plane, which provides favorable conditions for realizing large-format writing;

6. Since the light energy is not concentrated, the present utility model proposes to eliminate the seam between each light-controlled orientation field of view and improve the resolution by controlling the relationship between the size of the single field of view and the single translation distance;

7. The utility model has the advantages of high precision and arbitrary controllability of single exposure polarization pattern, large area writing and high efficiency, and is of great significance for designing and manufacturing large-size, high-precision and multi-functional liquid crystal optical devices.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some implementations of the present invention. For example, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

1 is a schematic structural diagram of a high-speed exposure patterned liquid crystal photo-alignment device provided by an embodiment of the present invention;

2 is a schematic diagram of the selection of the pulse laser frequency and the refresh frequency of the phase modulation device of the high-speed exposure patterned liquid crystal photo-alignment device in the embodiment of the present invention;

FIG. 3 is a schematic diagram of the peak absorption characteristic of a light polarization sensitive material used in the embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described implementation The examples are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The utility model discloses an illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device, comprising a pulsed light source and a collimation and polarization component, which are used for providing a light source for continuous stroboscopic exposure and realizing a single polarization collimation uniform surface light spot;

The high-speed exposure patterned liquid crystal photo-alignment device further includes a polarization pattern generating component, and the lighting system is connected to the polarization pattern generating component; the polarization pattern generating component includes a phase modulation device;

After the single or multiple pulses generated by the pulsed light source have undergone the steps of beam expansion, collimation and beam splitting, at the position of the phase modulator, the cumulative energy density is lower than the damage threshold of the phase modulation device; after the subsequent imaging steps, the cumulative energy density on the sample surface is The energy density is above the threshold energy of the light polarization sensitive material.

In the embodiment of the present invention, the pulsed light source is a pulsed laser. In other optional embodiments, the pulsed light source can also be generated by a continuous laser plus a mechanical or photoelectric light shield, or a pulsed LED or a continuous LED plus a controllable light source. Light barrier system.

Further, the pulsed light emitted by the pulsed light source forms a collimated uniform light spot with a divergence angle less than 10 mrad and a light intensity uniformity better than 80% after passing through the collimating and polarizing component.

Wherein, the repetition frequency of the pulsed light source 11 is 1 Hz to 10 kHz;

In the embodiment of the present invention, the pulse width of the pulsed light source is in the order of picoseconds to seconds, and the energy of a single pulse is in the order of nanojoules to millijoules; less than 5nm;

In a constant temperature and humidity environment, the center wavelength drift of the pulsed light source is less than 3nm; the half-wave width of the light source is less than 5nm, and more than 80% of the energy of the pulsed light source is concentrated within the half-width of the center wavelength.

Wherein, the influence of the pulsed light source on the phase delay of the output pattern of the polarization pattern generating part 2 satisfies the following formula:

where δ is the polarization angle of a single pixel set by the phase control device;

为误差造成的位相延迟。

Phase delay due to errors.

Wherein, the center wavelength shift of the pulsed light source and the half-width, temperature, and wave plate errors have less than 1% of the polarization degree phase error of the output pattern of the polarization pattern generating component.

After the incident light of the pulsed light source is phase-modulated by the polarization pattern generating component, the intensity ratio between the polarization direction and the direction perpendicular to the polarization direction is greater than 10:1.

In the embodiment of the present invention, the pulsed light source is a pulsed laser, and the pulse width of the pulsed laser is less than or equal to the image maintenance time of the phase modulation device. When an image of the phase modulation device is maintained, there is at least one pulsed laser peak irradiation. on the phase modulation device.

The collimating and polarizing components of the lighting system include collimating components and polarizing plates;

The collimating component is used to adjust the line light source or point light source to a parallel surface light source and output it to the polarization pattern generating component;

Among them, the polarizer is used to generate a single polarized light, and the polarizer is connected to the collimating component to control the initial polarization direction of the light to generate a surface light source with any polarization direction within the range of 0-179 degrees.

In the embodiment of the present utility model, as shown in FIG. 1 , the high-speed exposure patterned liquid crystal photo-alignment device using the above-mentioned illumination system further includes a polarization pattern generating component, an imaging detection component, a focus servo system and a motion control system sequentially connected with the above-mentioned illumination system. control part;

Among them, the polarization pattern generation part includes a quarter-wave plate and a phase modulation device connected in sequence, which are used to output a pixelated programmable polarization pattern to the workpiece; the phase modulator is connected with the imaging detection component; the phase modulation device is a liquid crystal phase modulation device. The modulation device is used to load a different phase in each pixel; specifically, the phase modulation device is a pixel-type phase retarder with adjustable phase difference; the polarization plane light source is reflected as a light spot containing different polarization information and transmitted to the light splitting component;

Among them, the phase delay modulation of the pulsed light source by the phase modulation device is greater than 2π; the phase modulation accuracy of a single gray level controlled by a computer program is better than 0.01π, so as to realize any phase delay modulation within one cycle; the phase modulation The phase delay drift of the device is less than 0.005π.

The imaging detection component is used to detect the image of the generated pattern; the focal length servo system includes a normally-on light source that is not sensitive to light polarization sensitive materials and a vertical direction correction component, which is used to correct the defocus phenomenon caused by motion; the imaging detection component also includes a miniature The imaging part is used for miniaturizing the polarization pattern output by the polarization pattern generating part, and writing it into the light polarization sensitive material;

The miniature imaging component includes an imaging objective lens group, the main axis of the optical path of the imaging objective lens group is perpendicular to the platform, and the motor drives the imaging objective lens group to move up and down in the vertical direction to form a focusing surface on the platform.

In the embodiment of the present invention, the motion control component is used to adjust the spatial position of the platform carrying the light polarization sensitive material, so as to realize the light field splicing. The platform is arranged under the imaging objective lens group and has a two-dimensional motion track, which is used to carry the light polarization sensitive material and drive the light polarization sensitive material to move in a two-dimensional plane under the driving of the motion control component, so that the light polarization sensitive material is moved in a two-dimensional plane. The surface of the imager is always kept on the focal plane of the imaging objective lens group; the motion control part is connected with the miniature imaging part, and is used for splicing the miniature polarized pattern light field.

In the embodiment of the present invention, the imaging detection assembly includes a first beam splitter, a tube lens, an imaging objective lens group, a polarizer, a first lens, and a first imaging CCD connected in sequence;

The front focal plane of the imaging objective lens group is located near the back focal plane of the tube lens; the imaging plane of the first imaging CCD is located on the front focal plane of the first lens; the back focal plane of the first lens is located on the front focal plane of the tube lens.

The focal length servo system includes a detection light source, a second lens, a second beam splitter, an imaging objective lens group, a second imaging CCD, and a motor connected in sequence;

Wherein, the detection light source is located on the front focal plane of the second lens; the second beam splitter is located on the back focal plane of the second lens; the imaging plane of the second imaging CCD is located on the front focal plane of the second lens; the motor drives the imaging objective lens group;

The first imaging CCD receives the reflected image projected onto the surface of the light polarization sensitive material, and the first imaging CCD and the phase modulator form a conjugate image.

Wherein, the quarter wave plate is arranged between the phase modulator and the imaging detection component;

The phase modulator is a liquid crystal spatial light modulator, which is a pixel-type phase retarder with adjustable phase difference δ; the polarization rotation direction is δ/2; the polarization direction of the incident light, the crystal axis direction of the phase modulation device, and the quarter-wave plate crystal. The axis direction forms an included angle of 0, 45, and 90 degrees.

In the embodiment of the present invention, the number of quarter-wave plates is two, and the polarization pattern generating component 2 includes a first quarter-wave plate, a phase modulation device, and a second quarter-wave plate connected in sequence. ;

The long axis direction of the first quarter wave plate, the crystal axis direction of the phase modulation device, and the crystal axis direction of the first quarter wave plate form an included angle of 0, 45, and 90 degrees.

And further, the motion control component also includes a controller and a motor drive device, and the controller is used to convert the collected optical path data into control signals and send them to each execution component;

The controller includes a motion control module, and the motion control module includes a platform motion control unit;

The motor drive device is used to drive the motor to drive the focusing platform and the platform movement, and the detection device is used to monitor the movement of the motor in real time, and send the movement position and speed of the motor to the motion control module;

The platform motion control unit is used to control the light polarization sensitive material to move in a two-dimensional plane, so as to realize the splicing of polarized light fields or the interconnection between different polarized light fields through the pattern splicing component.

In the embodiment of the present invention, the wavelength of the light emitted by the detection light source is any value between 550nm and 700nm;

Among them, the specified wavelength band reflection flat plate is a reflection flat plate coated with a wavelength reflection film of the detection light source.

In the embodiment of the present invention, the line light source or point light source emitted from the laser is adjusted to be a collimated polarized surface light source; the illumination light source is evenly irradiated on the phase modulator at a preset angle, through the quarter wave plate and the phase The modulator generates a pattern of arbitrary polarization distribution; further, a fixed miniature magnification is formed by the ratio of the focal length of the tube lens and the miniature objective lens, the polarization pattern output by the phase modulator is miniaturized, and then the polarization pattern light field is output; detection and adjustment of the miniature The distance between the objective lens and the light polarization sensitive material surface keeps the focal plane of the miniature objective always on the light polarization sensitive material surface; detect the size of the light spot projected on the light polarization sensitive material surface, and judge whether the light polarization sensitive material surface is on the focal plane of the objective lens ; Then record a single photo-controlled orientation onto the light-polarization-sensitive material; move the platform loaded with the light-polarization-sensitive material to the next designated position for the next pattern light field recording; splicing each orientation unit together Arbitrarily distributed light alignment structures are formed on the polarization-sensitive material.

Among them, the image reflected from the surface of the light polarization sensitive material passes through the miniature objective lens, the tube lens, the specified wavelength band reflection flat plate, and the first beam splitter in sequence, and then enters the first imaging CCD through the first lens, and the phase modulator and the first imaging CCD are located in The front focal plane of the tube lens is in a conjugate relationship. By controlling the up and down movement of the lens of the miniature objective lens, the clarity of the image of the first imaging CCD is adjusted to determine whether the focal plane of the microscopic objective lens is on the surface of the light polarization sensitive material, and the second imaging is calibrated The size of the laser spot in the CCD is used for focus monitoring for subsequent splicing; the contrast of the contour of the imaging spot projected onto the light polarization sensitive material is used to determine whether the focal plane of the objective lens is on the surface of the light polarization sensitive material.

In the embodiment of the present utility model, the wavelength of the light emitted by the detection light source is any value between 550 nm and 650 nm; the second lens reflects the light spot projected on the surface of the light polarization sensitive material into the second imaging CCD, and maps Z through the spot diameter Axis servo focusing position, adjust the upper and lower height of the Z-axis lens, the spot diameter in the second imaging CCD can always be kept as R, so that the second imaging CCD can detect the size of the spot projected on the light polarization sensitive material surface to judge the light Whether the polarization-sensitive material surface is in the focal plane of the objective.

Moving the platform carrying the light polarization-sensitive material to the next designated position for the next orientation is achieved through the following steps: the controller transmits the position data to the motion control module, and the motion control module converts the received data into control signals and Send it to the motor driver, 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 sends the motion position and speed of the motor to the motion control module; then the motion control module will focus on the platform And the current position and speed of the sample stage are fed back to the controller.

Specifically, after the single-shot photo-controlled orientation is recorded on the light-polarization-sensitive material, the moving distance for moving the platform carrying the light-polarization-sensitive material to the next specified position through the motion control module is the size of the single-shot alignment unit, and The moving method is to move and scan row by row. The moving method is not limited in the present invention.

Among them, the relationship between the frequency of the pulse laser and the refresh frequency of the phase modulation device is shown in Figure 2. The pulse laser frequency of the pulse laser corresponds to the frequency of the phase modulation device, and the pulse width is less than or equal to the image maintenance time of the phase modulation device, that is, when the phase An image of the modulation device is maintained while a pulsed laser peak is irradiated on the phase modulation device.

During the image maintenance time of the phase modulation device, a plurality of pulsed laser peaks may also be irradiated on the receiving window of the phase modulation device, which can strengthen the single exposure energy.

The wavelength absorption characteristics of the photo-controlled alignment material used in this embodiment are shown in Figure 3; the material used is an azo photo-alignment material, which corresponds to the material 3 in Figure 3, and can be obtained when a laser with a wavelength of 442 nm is used for illumination. For better light-controlled alignment effect, pulsed laser light sources with different wavelengths can also be selected according to the light alignment materials, or corresponding light alignment materials can be selected according to the pulsed laser light sources with different wavelengths. The miniature parts use a 20-fold miniature objective lens, that is, the spot area is reduced by 400 times, the energy density is increased by 400 times, and the size of a single pixel is only 0.4 microns after miniaturization, which can realize high-precision pattern information exposure and direct writing. At this time, the photosensitive amount of the photo-alignment material was 50 mJ/cm ² , which was higher than the photo-controlled alignment energy threshold and lower than its damage threshold.

It should be noted that the "flicker" defined in the present invention refers to emitting light and/or quenching according to a certain preset frequency.

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

1. The present utility model utilizes the pulsed illumination system to control the phase change of a single exposure area in real time when applied to high-speed exposure patterned liquid crystal photo-alignment, so as to achieve high-precision and high-resolution exposure;

2. The utility model utilizes the characteristics of high pulse laser energy, short pulse width and high repetition frequency to realize single-frame polarization pattern recording based on single or multiple pulses, and has the advantages of large area, high efficiency and good reliability;

3. The light source of the present invention adopts the ultraviolet or blue light after beam expansion and collimation, adjusts the light field with a phase modulator, and can generate different polarization phases, and then combines the imaging system for miniaturization, and finally realizes polarization modulation in any direction in the unit pixel. , effectively overcome the problems of "single polarization orientation, low flexibility and low processing efficiency";

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 uses a high-precision platform to precisely control the sample to move on a two-dimensional plane, which provides favorable conditions for realizing large-format writing;

6. The utility model has the advantages of high precision and arbitrary controllability of single exposure polarization pattern, large area writing, and high efficiency, which is of great significance for designing and manufacturing large-size, high-precision, and multi-functional liquid crystal optical devices.

All the above-mentioned optional technical solutions can be combined arbitrarily to form optional embodiments of the present invention, which will not be repeated here.

It should be noted that when the illumination system provided in the above-mentioned embodiment and applied to the high-speed exposure patterned liquid crystal photo-alignment device executes the illumination mode, only the division of the above-mentioned functional modules is used as an example. The above-mentioned function allocation is completed by different function modules, that is, the internal structure of the system is divided into different function modules, so as to complete all or part of the functions described above.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above embodiments may be implemented by hardware.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection of the utility model.

Claims (10)

1. an illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device, characterized in that the illumination system comprises a pulsed light source and a collimated polarizing component for providing a light source for continuous stroboscopic exposure and realizing a single polarization alignment. Straight and uniform light spot; The high-speed exposure patterned liquid crystal photo-alignment device further includes a polarization pattern generating component, the illumination system is connected to the polarization pattern generating component, and the polarization pattern generating component includes a phase modulation device; After the single or multiple pulsed beams generated by the pulsed light source have undergone the steps of beam expansion, collimation and beam splitting, at the position of the phase modulator, the cumulative energy density is lower than the damage threshold of the phase modulation device; surface, the cumulative energy density is higher than the threshold energy of the light polarization sensitive material. 2. The illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device according to claim 1, wherein the pulsed light source is a pulsed laser or a continuous laser plus a mechanical or photoelectric light shield to generate, or a pulsed light source is used. LED or continuous LED plus controllable shutter system. 3 . The illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device according to claim 1 , wherein the pulsed light emitted by the pulsed light source passes through the collimating and polarizing component to form a divergence angle less than 10 mrad and a light intensity of less than 10 mrad. 4 . The uniformity is better than 80% of the collimated uniform spot. 4. The illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device according to claim 1, wherein the repetition frequency of the pulsed light source is 1 Hz to 10 kHz; The pulse width of the pulsed light source is in the order of picoseconds to seconds, and the energy of a single pulse is in the order of nanojoules to millijoules. 5. The illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device according to claim 1, wherein the wavelength of the pulsed light source is between 340 nm and 600 nm, and the half-width of the pulsed light source is less than 5 nm; In a constant temperature and humidity environment, the center wavelength drift of the pulsed light source is less than 3 nm; the half-wave width of the light source is less than 5 nm, and more than 80% of the energy of the pulsed light source is concentrated within the half-width of the center wavelength. 6. The illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device according to claim 1, wherein the influence of the pulsed light source on the phase retardation of the output pattern of the polarization pattern generating component satisfies the following formula:

where δ is the polarization angle of a single pixel set by the phase control device;

Phase delay due to errors. 7. The illumination system applied to the high-speed exposure patterned liquid crystal photo-alignment device according to claim 6, wherein, The center wavelength drift of the pulsed light source and the half-width, temperature, and wave plate errors have less than 1% of the polarization degree phase error of the output pattern of the polarization pattern generating component. 8. The illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device according to claim 1, wherein after the incident light of the pulsed light source is phase-modulated by the polarization pattern generating component, the polarization direction and The intensity ratio in the direction perpendicular to the polarization direction is greater than 10:1. 9 . The illumination system of claim 1 , wherein the pulsed light source is a pulsed laser, and the pulse width of the pulsed laser is less than or equal to the phase modulation device. 10 . When an image of the phase modulation device is maintained, there is at least one pulsed laser peak irradiated on the phase modulation device. 10 . The illumination system applied to a high-speed exposure patterned liquid crystal photo-alignment device according to claim 1 , wherein the illumination system further comprises a collimating and polarizing component, and the collimating and polarizing component comprises a collimating component and a polarizing component. 11 . partial film; The collimating component is used to adjust the line light source or the point light source into a parallel surface light source and output it to the polarization pattern generating component; The polarizer is used to generate single polarized light, and the polarizer is connected to the collimating component to control the initial polarization direction of the light to generate a surface light source with any polarization direction within the range of 0-179 degrees.

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