CN111585169B

CN111585169B - Liquid crystal laser display panel and construction method thereof

Info

Publication number: CN111585169B
Application number: CN201910123541.6A
Authority: CN
Inventors: 赵永生; 徐法峰; 姚建年
Original assignee: Institute of Chemistry CAS
Current assignee: Institute of Chemistry CAS
Priority date: 2019-02-18
Filing date: 2019-02-18
Publication date: 2021-05-28
Anticipated expiration: 2039-02-18
Also published as: CN111585169A

Abstract

The invention discloses a liquid crystal laser display panel and a construction method thereof. The panel comprises RGB pixel arrays which are periodically arranged, wherein each RGB pixel array comprises a polymer micro-template and a liquid crystal microstructure; the polymer micro-template is used as a blank pixel, and the liquid crystal micro-structure is positioned in the polymer micro-template; wherein the liquid crystal microstructure comprises a liquid crystal material and organic laser dye molecules. The liquid crystal micro laser pixel array has the characteristic of periodic arrangement, is easy to realize laser output of color mixing, and is easy to realize full-color laser display in a specific excitation mode.

Description

Liquid crystal laser display panel and construction method thereof

Technical Field

The invention belongs to the field of laser display, and particularly relates to a liquid crystal laser display panel and a construction method thereof.

Background

Laser display, which utilizes the characteristics of high monochromaticity and high brightness of laser emission, has become a revolutionary technology in the display industry due to its wide gamut coverage, high color saturation and high color contrast ratio. The application of laser display technology to portable display devices has been hampered by the lack of suitable full color display panels. Therefore, it is of great significance to develop a structure capable of realizing pixelation of full-color laser emission. One effective strategy is to construct a periodic laser array as a display panel using red, green, blue (RGB) microlasers as elementary pixels. To date, RGB laser arrays have been demonstrated by various schemes such as printing-type array preparation schemes, chemical vapor deposition array preparation schemes, and template-assisted liquid-phase self-assembly array preparation schemes, etc., which can be used as color laser display panels.

However, due to material compatibility and complex fabrication technology issues, integrating RGB laser arrays on a single panel to achieve full color laser displays remains a significant challenge.

Disclosure of Invention

The invention provides a liquid crystal laser display panel, which comprises an RGB pixel array which is periodically arranged, wherein the RGB pixel array comprises a polymer micro-template and a liquid crystal micro-structure; the polymer micro-template is used as a blank pixel, and the liquid crystal micro-structure is positioned in the polymer micro-template; wherein the liquid crystal microstructure comprises a liquid crystal material and organic laser dye molecules.

According to the liquid crystal laser display panel, the liquid crystal material is a mixture of liquid crystal and a chiral agent. For example, the liquid crystal may be at least one of nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, and discotic liquid crystal, and by way of example, the liquid crystal may be nematic liquid crystal, for example, the liquid crystal may be E7, purchased from shijia honest-and-memorable-perpetuation display materials ltd. For example, the chiral agent may be at least one of a left-handed chiral agent and a right-handed chiral agent, and the chiral agent is a right-handed chiral agent, for example, the chiral agent may be R811, purchased from shijiazhuang honest Yonghua display materials, ltd. Wherein, the mass ratio of the liquid crystal to the chiral agent in the liquid crystal material can be 100 (1-30), such as 100 (5-20); as an example, the mass ratio may be 100:5 (denoted as LC-1), 100:12 (denoted as LC-2), 100:20 (denoted as LC-3). As an example, the liquid crystal material can be obtained by doping the liquid crystal E7 with the chiral agent R811 in the above-described ratio.

Examples of the liquid crystal E7 include cyanobiphenyls such as 2-cyanobiphenyl, 4-cyano-4' -pentylbiphenyl, and the like.

The chiral agent R811 includes, for example, 4- (4' -hexyloxy) benzoyloxybenzoic acid- (R) - (-) -2 octyl alcohol ester, the structural formula of which is shown below:

according to the liquid crystal laser display panel of the present invention, the organic laser dye molecules may be selected from one, two or more of oligostyrene type dye (o-MSB), coumarin type dye (C30), 4- (dimethylene) -2-methyl-6- (4-dimethylaminostyryl) -4 h-furan (DCM), and the like. For example, the mass ratio of the liquid crystal material to the organic laser dye molecules may be 100 (0.5-3), such as 100 (1-2); as an example, the mass ratio may be 100:1, 100:1.5, 100: 1.2.

According to the liquid crystal laser display panel, the periodic arrangement may be that RGB pixel array units are sequentially arranged, and the RGB pixel array units are composed of an R array, a G array, and a B array, which are sequentially arranged.

According to the liquid crystal laser display panel of the invention, the RGB pixel array may be a square structure, such as a horizontal and vertical parallel N × N array.

According to the liquid crystal laser display panel, the liquid crystal microstructure can be used as a micro laser pixel.

The invention also provides a construction method of the liquid crystal laser display panel, which comprises the following steps:

(1) injecting printing ink into the polymer micro-template, and printing to obtain an RGB pixel array;

(2) under the excitation of laser, the sub-pixels in the RGB pixel array emit single-mode RGB laser and mixed-color laser, and the liquid crystal laser display panel is obtained.

According to the method of the invention, in step (1), the printing ink comprises a mixture of liquid crystal material and organic laser dye molecules; the liquid crystal material and the organic laser dye molecules have the meaning and the proportion as described above.

For example, the printing ink includes printing ink one, printing ink two, and printing ink three. By way of example, the printing ink one comprises a liquid crystal material one and an organic laser dye one, wherein the liquid crystal material one can be LC-1, and the organic laser dye one can be o-MSB. For example, the second printing ink comprises a second liquid crystal material and a second organic laser dye, the second liquid crystal material may be LC-2, and the second organic laser dye may be C30. For example, the printing ink three comprises a liquid crystal material three and an organic laser dye three, wherein the liquid crystal material three can be LC-3, and the organic laser dye three can be DCM.

According to the method of the present invention, in step (1), the polymer micro-template may be prepared by spin-coating an organic solution of a polymer on a magnesium fluoride substrate, and etching the solution. For example, the polymer may be polymethyl methacrylate. For example, the organic solution is a chlorobenzene solution. For example, the concentration of the organic solution of the polymer (e.g., a solution of polymethyl methacrylate in chlorobenzene) can be 0.05-0.5g/mL, such as 0.08-0.3g/mL, and as an example, the concentration can be 0.1g/mL, 0.2 g/mL. For example, the etching may be electron beam etching. The polymer micro-template may be polygonal in shape, and illustratively, square in shape. The polymer micro-template may have a side length of 10-100 microns, illustratively 50 microns.

According to the method of the present invention, in the step (1), the printing may be contact-based printing. The printing may comprise the steps of: a. controlling the micro-operation arm to move a glass needle (for example, the glass needle is an inverted conical hollow glass needle point with an opening at the lower end, and the inner diameter of the needle point can be 5-20 micrometers, and is 10 micrometers as an example) on the micro-operation arm to be above the printing ink; b. operating the mechanical arm to enable the needle head to be inserted into the printing ink, and sucking the printing ink into the needle head by utilizing the capillary action; c. and lifting the needle head to the position above the polymer micro-template, setting a certain release voltage, and injecting the sample into the micro-template. Wherein the release voltage may be 0.5-3.0V, such as 0.8-2.0V, and as an example, the release voltage may be 1.0V.

According to the method of the invention, in step (1), the printing inks may be injected into the polymeric micro-template in columns. For example, an R array is printed first, then a G array is printed, then a B array is printed, and the R array, the G array, and the B array obtained by printing in sequence are RGB pixel array units. And the three adjacent RGB pixels in the same row form the sub-pixels of the RGB pixel array.

According to the method of the present invention, in the step (2), the laser may be a femtosecond laser with a wavelength of 380-420nm, such as 390-401nm, for example, 400 nm.

According to the method of the present invention, in step (2), when the sub-pixels are individually excited, single-mode RGB laser emission can be obtained. When different sub-pixel combinations are excited, laser with mixed colors can be obtained; the laser emission of the mixed color includes laser emission of at least one of cyan (BG mixed color), orange (GR mixed color), magenta (BR mixed color), and white (RGB mixed color).

According to the method of the present invention, in step (2), the position of laser excitation can be controlled by using a digital micromirror device, and the excitation position is designed into a specific pattern, thereby realizing the selective excitation of different sub-pixels of the polymer micro-template. Further, the specific pattern can be edited in software associated with the digital micromirror element, resulting in different excitation masks.

The invention has the beneficial effects that:

1. the invention provides a liquid crystal laser display panel, which comprises a polymer micro-template used as a blank pixel and a liquid crystal microstructure injected into the micro-template by ink-jet printing; the liquid crystal microstructure comprises a liquid crystal material and organic laser dye molecules doped in the liquid crystal material. The liquid crystal material provides a distributed optical feedback resonant cavity required by laser emission, and the organic laser dye molecules provide optical gain. The liquid crystal material with the distributed optical feedback function has excellent material compatibility and is easy to be mixed with organic laser dye molecules with optical gain; the organic laser dye molecule-doped liquid crystal microstructure with optical gain can form a micro-nano resonant cavity, effective optical oscillation is easy to realize, and low-threshold laser mode output is facilitated; the organic laser dye molecule doped liquid crystal microstructure with optical gain can also realize the emission of single-mode laser through distributed optical feedback, form high-purity laser, and is beneficial to realizing the color display with wide color gamut and high saturation. The liquid crystal material doped with organic laser dye molecules has excellent flowing property, and is easy to inject into a specific template to realize display pixels with specific shapes; the liquid crystal material doped with organic laser dye molecules has excellent processing performance, and is easy to realize the preparation of a liquid crystal micro laser pixel array by a printing technology and the construction of a laser display panel; the liquid crystal micro laser pixel array has the characteristic of periodic arrangement, is easy to realize laser output of color mixing, and is easy to realize full-color laser display in a specific excitation mode.

In the liquid crystal microstructure doped with organic laser dye molecules, the organic optical gain dye and the liquid crystal distributed feedback resonant cavity are mixed together in a doping mode, and the mixture is uniform and stable, so that the liquid crystal micro laser pixel with a stable structure can be obtained, the light emitted by the optical gain dye can be effectively resonated in the liquid crystal microstructure, and the low-threshold laser emission can be realized.

In the liquid crystal micro laser pixel, liquid crystal provides a distributed feedback resonant cavity, and the light emission of the organic optical gain dye realizes effective distributed feedback resonance and single-mode laser emission with high color purity.

In the liquid crystal micro laser pixel, pixels emitting laser with different colors can be combined to emit light, so that multi-color mixing is realized, and multi-color laser pattern display can be realized.

In the liquid crystal micro laser pixel array, the selective mask excitation of the digital micro mirror element can be used for realizing the display of specific graphic patterns and realizing the laser display of single color, multiple colors and full color.

2. The invention also provides a preparation method of the liquid crystal laser display panel, which has the advantages of low cost, simple method, environmental friendliness and large-scale preparation.

Drawings

FIG. 1 is a characteristic diagram of the liquid crystal material used in example 1 of the present invention.

FIG. 2 is a graph showing the properties of organic laser dye molecules used in example 1 of the present invention.

Fig. 3 is a schematic view of a process for manufacturing a liquid crystal laser display panel according to embodiment 1 of the present invention.

Fig. 4 is a characterization diagram of laser emission properties of a liquid crystal micro-laser pixel in embodiment 1 of the invention.

Fig. 5 is a representation diagram of the full-color laser color mixing provided in embodiment 1 of the present invention.

Fig. 6 is a schematic diagram of laser display of a specific pattern provided in embodiment 1 of the present invention.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to specific embodiments. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

Unless otherwise indicated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

Digital micromirror device: based on a digital micromirror device developed by TI (Texas instruments, USA) corporation, model number DLP470 NE.

Liquid crystal E7: purchased from Shijiazhuang Chengninghua display materials, Inc.

Chiral agent R811: purchased from Shijiazhuang Chengninghua display materials, Inc.

The liquid crystal material is obtained by doping a chiral agent R811 into liquid crystal E7, wherein the mass ratio of E7 to R811 in LC-1 is 100:5, the mass ratio of E7 to R811 in LC-2 is 100:12, and the mass ratio of E7 to R811 in LC-3 is 100: 20.

Example 1

The liquid crystal laser display panel comprises an RGB pixel array which is periodically arranged, and the RGB pixel array liquid crystal laser display panel comprises a polymer micro-template which is used as a blank pixel and a liquid crystal microstructure which is injected into the micro-template by ink-jet printing; the liquid crystal microstructure comprises a liquid crystal material and organic laser dye molecules doped in the liquid crystal material.

The printing ink for ink-jet printing comprises printing ink I (a mixture of liquid crystal materials LC-1 and o-MSB in a mass ratio of 100: 1), printing ink II (a mixture of liquid crystal materials LC-2 and C30 in a mass ratio of 100: 1.5) and printing ink III (a mixture of liquid crystal materials LC-3 and DCM in a mass ratio of 100: 1.2).

FIG. 1 is a graph showing the characteristic properties of the liquid crystal material used in this example (scale: 1 mm). As can be seen from fig. 1, the three liquid crystal materials have different transmission spectra. The position of the reflective forbidden band is significantly different, spanning the whole visible region. The physical representation also illustrates the three color reflections achieved. This is favorable to realizing the laser emergence of RGB three-colour to provide the basis for realizing full color laser.

FIG. 2 is a graph showing the properties of organic laser dye molecules used in this example. As can be seen from fig. 2, the fluorescence emission of the three organic laser dye molecules is in the standard red, green and blue wavelength bands, and also covers the whole visible light region, and can be combined with the corresponding liquid crystal material, thereby satisfying the precondition of realizing full-color laser emission.

Based on the selected liquid crystal material and organic laser dye molecules, three kinds of printing ink are injected into the polymer micro template in a contact substrate type printing mode to prepare the display panel. The printing process comprises the following steps: a. controlling the micro-operation arm to move a glass needle (the glass needle is an inverted conical hollow glass needle point with an opening at the lower end, and the inner diameter of the needle point can be 10 microns) on the micro-operation arm above the printing ink; b. operating the mechanical arm to enable the needle head to be inserted into the printing ink, and sucking the printing ink into the needle head by utilizing the capillary action; c. the needle head is lifted to the position above the polymer micro-template, a release voltage of 1.0V is set, and the printing ink is injected into the micro-template.

Fig. 3 illustrates a schematic diagram of a process for manufacturing a display panel in detail. The polymer micro-template was prepared by spin-coating a solution of polymethyl methacrylate in chlorobenzene at a concentration of 0.1g/mL on a magnesium fluoride substrate, followed by electron beam etching. The pattern on the micro-template can be designed by software, and the finally manufactured micro-template is a horizontal-vertical parallel N-N array with a square structure with the side length of 50 micrometers as a blank pixel array. The liquid crystal ink doped with the selected organic laser dye molecules shows excellent flowing performance, and the printing ink is injected into the micro-template in rows, wherein when the R array is printed, one row of the R array is printed every two rows, and a spare position is reserved for the arrays of other subsequent colors. The R array is printed, then the G array is printed, and then the B array is printed, so that the RGB pixel array which is periodically arranged is formed. Three adjacent RGB pixels in the same row constitute a complete display pixel, wherein the three RGB pixels constitute sub-pixels thereof.

Fig. 4 tests the laser properties of the liquid crystal microstructure as a sub-pixel (25 micron scale). The selected liquid crystal material provides a distributed optical feedback resonant cavity required by laser emission, organic dye molecules provide optical gain, and high-purity RGB single-mode laser emission is realized under the excitation of femtosecond laser (excitation wavelength of 400nm) along with the increase of pumping power, so that the display of high color gamut coverage and high saturation is favorably realized.

Fig. 5 shows the results of the color mixing characterization of the laser (150 microns on scale). As can be seen from fig. 5, by exciting different sub-pixel combinations, laser emissions of single and mixed colors, including red (R), green (G), blue (B), cyan (BG), orange (GR), magenta (BR), and white (RGB), are obtained from the prepared plurality of "LCLD" patterns.

Fig. 6 shows the principle of laser display of a specific pattern (50 micron scale). Based on a display panel constructed by a liquid crystal micro laser pixel array, the English letters of RGB (red, green and blue) are displayed by adopting the excitation of a digital micro-mirror element. On the constructed 3 × 9 pixel array, one pixel includes three RGB sub-pixels arranged laterally. The digital micromirror device can control the position of the excitation light impinging on the panel, thereby displaying a desired pattern. These locations to be activated can be designed in a specific pattern to achieve selective activation of the different sub-pixels of the panel. These patterns can be edited in software, thereby resulting in different excitation masks. The different excitation masks are indicated by black boxes in the figure. By changing the mask in the software, a display of the capital english letter "L" of the three colors red, green and blue is obtained on the 3 x 9 pixel array.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The liquid crystal laser display panel is characterized by comprising an RGB pixel array which is periodically arranged, wherein the RGB pixel array comprises a polymer micro-template and a liquid crystal microstructure; the polymer micro-template is used as a blank pixel, and the liquid crystal micro-structure is positioned in the polymer micro-template; wherein the liquid crystal microstructure comprises a liquid crystal material and organic laser dye molecules.

2. The liquid crystal laser display panel according to claim 1, wherein the liquid crystal material is a mixture of a liquid crystal and a chiral agent; the mass ratio of the liquid crystal to the chiral agent is 100 (1-30).

3. The liquid crystal laser display panel according to claim 2, wherein the liquid crystal is selected from at least one of nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, and discotic liquid crystal.

4. The liquid crystal laser display panel according to claim 3, wherein the liquid crystal is a nematic liquid crystal.

5. The liquid crystal laser display panel according to claim 2, wherein the chiral agent is at least one selected from a left-handed chiral agent and a right-handed chiral agent.

6. The liquid crystal laser display panel according to claim 5, wherein the chiral agent is a dextrorotatory chiral agent.

7. The LC laser display panel of claim 1, wherein the organic laser dye molecules are selected from one, two or three of oligostyrene dyes (o-MSB), coumarin dyes (C30) and 4- (dimethylene) -2-methyl-6- (4-dimethylaminostyryl) -4-hydro-furan (DCM).

8. The LC laser display panel of any one of claims 1-7, wherein the mass ratio of the LC material to the organic laser dye molecules is 100 (0.5-3).

9. The lcd laser panel of claim 1, wherein the periodic arrangement is an sequential arrangement of RGB pixel array units, and the RGB pixel array units are composed of an R array, a G array, and a B array, which are sequentially arranged.

10. The liquid crystal laser display panel of claim 1, wherein the polymer micro-template is prepared by spin coating an organic solution of a polymer on a magnesium fluoride substrate by etching.

11. The liquid crystal laser display panel according to claim 10, wherein the polymer is polymethyl methacrylate, and the organic solution is chlorobenzene.

12. The liquid crystal laser display panel according to claim 10 or 11, wherein the concentration of the organic solution of the polymer is 0.05 to 0.5 g/mL.

13. The lcd laser panel of claim 10, wherein the etching is electron beam etching.

14. The method of constructing a liquid crystal laser display panel according to any one of claims 1 to 13, comprising the steps of:

15. The method for fabricating a liquid crystal laser display panel according to claim 14, wherein in the step (1), the printing ink includes a liquid crystal material having a meaning as set forth in claim 2 and organic laser dye molecules having a meaning as set forth in claim 7 or 8.

16. The method for constructing a liquid crystal laser display panel according to claim 14 or 15, wherein the printing ink includes printing ink one, printing ink two, and printing ink three.

17. The method for constructing a liquid crystal laser display panel according to claim 14, wherein the printing is contact-based printing; the printing comprises the following steps: a. controlling the micro-operation arm to move the glass needle on the micro-operation arm to be above the printing ink; b. operating the mechanical arm to enable the needle head to be inserted into the printing ink, and sucking the printing ink into the needle head by utilizing the capillary action; c. and lifting the needle head to the position above the polymer micro-template, setting a release voltage of 0.5-3.0V, and injecting the printing ink into the micro-template.

18. The method for fabricating the liquid crystal laser display panel according to claim 16, wherein in the step (1), the printing inks are injected into the polymer micro-template in a row;

the method comprises the steps of firstly printing to obtain an R array, then printing a G array and then printing a B array, wherein the R array, the G array and the B array which are sequentially printed are RGB pixel array units, and three adjacent RGB pixels in the same row form sub-pixels of the RGB pixel array.

19. The method as claimed in claim 14, wherein in the step (2), the laser is a femtosecond laser with a wavelength of 380-420 nm.

20. The method of claim 14, wherein in the step (2), when the sub-pixels are individually activated, single-mode RGB laser emission is obtained.

21. The method of claim 14, wherein a mixed color laser emission is obtained when different sub-pixel combinations are excited.

22. The method of claim 21, wherein the laser emission of the mixed color comprises at least one of cyan (BG mixed color), orange (GR mixed color), magenta (BR mixed color), and white (RGB mixed color).

23. The method for fabricating the liquid crystal laser display panel according to any one of claims 14 and 19 to 22, wherein in the step (2), the digital micro-mirror device is used to control the position of laser excitation, and the excitation position is designed into a specific pattern, thereby realizing the selective excitation of different sub-pixels of the polymer micro-template; the specific pattern is edited in software associated with the digital micromirror device, resulting in different excitation masks.