Transparent flexible liquid crystal display film based on PDLC (Polymer Dispersed Liquid Crystal) and manufacturing method thereof

Abstract

The invention discloses a transparent flexible liquid crystal display film based on PDLC and a manufacturing method thereof, and belongs to the field of liquid crystal display. The conductive film comprises a first conductive film and a second conductive film, the surface of the first conductive film is provided with a first conductive layer, the surface of the second conductive film is provided with a second conductive layer, and a PDLC coating is coated between the first conductive layer and the second conductive layer; the first conductive layer is etched to form a plurality of cells, each cell is provided with a through micropore, the micropores are filled with conductive slurry, the conductive slurry is connected with a cell outgoing line, and each cell outgoing line is connected to an outgoing line terminal; and a collinear cathode terminal is welded on the second conductive layer. The manufacturing method comprises the following steps: etching a plurality of cells on the first conductive layer; through micropores are formed in the cells and filled with conductive slurry; the conductive slurry is connected with the cell leading-out wire and is connected to the leading-out wire terminal; bonding pads are formed on the two end faces of the micropore; the second conductive layer is welded with a collinear cathode terminal; and coating a PDLC (polymer dispersed liquid crystal) coating.

Description

Technical Field

[0001] The present invention belongs to the field of liquid crystal displays, and particularly relates to a transparent flexible liquid crystal display film based on PDLC and a manufacturing method thereof. Background Art

[0002] In the late 1980s, the PDLC technology was invented by the University of Kent in Texas, USA and licensed to Polytronix, Inc. in the USA for commercial mass production of liquid crystal film products. The earliest liquid crystal film products were mainly applied to the production of laminated liquid crystal dimming glass and were first applied to the projects of NASA in the early 199s. In the mid-1990s, manufacturers in South Korea, Japan and other countries began to enter this field, and domestic manufacturers in China also invested in the production field more than a decade after the advent of PDLC liquid crystal films. PDLC is called a dimming film in Chinese and mainly works between the scattering state and the transparent state, and adjusts the transparency through voltage. When no external voltage is applied, the optical axis orientations of liquid crystal particles are random, the effective refractive index does not match the refractive index of the polymer, and the incident light is strongly scattered, and the film is opaque or semi-transparent. After applying an external voltage, the optical axes of the liquid crystal particles are arranged perpendicular to the film surface and are consistent with the electric field direction. The ordinary light refractive index of the particles is basically matched with the refractive index of the polymer, and the incident light does not scatter, and the film is transparent.

[0003] At present, PDLC is mainly applied to liquid crystal dimming glass for privacy protection in commercial spaces, hotel decoration, projection display and other fields. With the development of technology, it is gradually applied to dimming control solutions such as automotive sunroofs, ships, and aircraft windows, and also has extensive applications in the home decoration field and the office field, such as bathroom glass, high-grade meeting room partitions, etc., and can achieve personalized zoned display of fixed patterns and texts. After years of research, it has been found that under specific ratios and configurations, the PDLC material can be driven at a lower voltage under the action of direct current and alternating current, enabling it to have the ability to display dynamic texts and patterns, which is quite different from the existing LED display technology, meets the personalized needs of the market, can achieve one-screen dual-sided display, and has the characteristics of ultra-thin, ultra-transparent, energy-saving, novel, etc. In particular, there is a great demand in scenarios with special requirements for lighting and permeability, such as subway and bullet train windows, shopping mall and supermarket display windows, as well as large commercial and station ceiling hanging displays. Summary of the Invention

[0004] The purpose of the present invention is to provide a transparent flexible liquid crystal display film based on PDLC to further simplify the structure and process and further improve the yield.

[0005] Another purpose of the present invention is to provide a manufacturing method of a transparent flexible liquid crystal display film based on PDLC.

[0006] The technical solution of the present invention is: a transparent flexible liquid crystal display film based on PDLC, including a transparent first conductive film and a transparent second conductive film. The surface of the first conductive film has a first conductive layer, and the surface of the second conductive film has a second conductive layer. The first conductive layer and the second conductive layer are arranged opposite to each other and a PDLC coating is applied therebetween; A plurality of cells are etched on the first conductive layer of the first conductive film. Each cell is provided with a through micropore, and the micropore is filled with a conductive paste. Each micropore filled with the conductive paste is respectively connected with a cell lead-out wire, and the first conductive film is provided with a lead-out terminal, and each cell lead-out wire is respectively connected to the lead-out terminal; A common-line cathode terminal is welded on the second conductive layer of the second conductive film.

[0007] As a further improvement of the present invention, pads are respectively arranged at two end faces of the micropore. The pads cover the periphery of the micropore, and the thickness of the pads is less than the thickness of the PDLC coating.

[0008] As a further improvement of the present invention, the cells are square.

[0009] A manufacturing method of a transparent flexible liquid crystal display film based on PDLC includes the following steps: A. Laser-etch a plurality of cells on the first conductive layer of the first conductive film; B. Form a through micropore on each cell, pour the conductive paste into the micropore for hole filling. After the conductive paste is fully connected and cured with the first conductive layer, each cell obtains a conductive channel; C. The conductive paste filled in each micropore is connected with a cell lead-out wire, and each cell lead-out wire is connected to the lead-out terminal; D. Screens are respectively formed at two end faces of the micropore by screen printing to ensure that the screens cover the periphery of the micropore; E. Weld a common-line cathode terminal on the surface of the second conductive layer of the second conductive film; F. Coat a PDLC coating between the first conductive layer and the second conductive layer to integrally connect the first conductive film and the second conductive film, forming a transparent flexible liquid crystal display film based on PDLC.

[0010] Further, in step C, if both sides of the first conductive film have the first conductive layer, the cell lead-out wires are directly formed by laser etching on the first conductive layer on the side where the cells are not etched; if only one side of the first conductive film has the first conductive layer, the transparent conductive paste is screen-printed on the side of the first conductive film without the first conductive layer to form the cell lead-out wires.

[0011] The beneficial effects of the present invention are: 1. The present invention forms a transparent flexible liquid crystal display film by two conductive films (a first conductive film and a second conductive film) and a PDLC coating coated therebetween. The structure is simple, and it has the characteristics of being ultra-thin (with a thickness of only 0.27 mm), ultra-transparent (the light transmittance of the transparent area is 85%-95%), and energy-saving (the power per square meter is only 5 watts), 2. The present invention forms a display cell array by directly etching cells on the surface of the first conductive layer. Combined with the PDLC coating, the PDLC coating at the corresponding position can be made to display transparently by energizing the cells, so as to obtain the display of any pattern, and it can be displayed on both sides. The present invention sets micropores in each cell, fills conductive paste therein to achieve circuit conduction, and reliably fixes the conductive paste and the cell lead-out wire through pads. The micropores and the cell lead-out wires are extremely thin and not easily visible to the naked eye, and do not affect the display effect of text and patterns, 3. The manufacturing method of the present invention is simple, easy to implement, very easy to achieve mass production, the yield rate is greatly improved, and the cost will also be greatly reduced, having good practicability. Description of the Drawings

[0012] Figure 1 is a schematic structural diagram of the first conductive film in the present invention; Figure 2 is a schematic structural diagram of the second conductive film in the present invention; Figure 3 is a schematic structural diagram of the cell in the present invention; Figure 4 is Figure 3 the A-A view in Figure 5 is Figure 3 the B-B view in Figure 6 is a display state diagram of the specific implementation manner of the present invention.

[0013] In the figure, 1 - first conductive film; 101 - first conductive layer; 2 - second conductive film; 201 - second conductive layer; 3 - PDLC coating; 4 - micropore; 5 - conductive paste; 6 - pad; 7 - cell; 8 - cell lead-out wire; 9 - lead-out wire terminal; 11 - common-line cathode terminal. Specific Implementation Manner

[0014] The present invention will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0015] Example 1, As Figures 1-5As shown in the figure, a transparent flexible liquid crystal display film based on PDLC includes a transparent first conductive film 1 and a transparent second conductive film 2. The surface of the first conductive film 1 has a first conductive layer 101, and the surface of the second conductive film 2 has a second conductive layer 201. The first conductive layer 101 and the second conductive layer 201 are arranged opposite to each other, and a PDLC coating 3 is coated therebetween. On the first conductive layer 101 of the first conductive film 1, a plurality of closed and independent cells 7 are etched. Each cell 7 is provided with a through micropore 4, and the micropore 4 is filled with a conductive paste 5. Each conductive paste 5 filled in each micropore 4 is respectively connected to a cell lead-out wire 8. An lead-out wire terminal 9 is provided on the first conductive film 1, and each cell lead-out wire 8 is respectively connected to the lead-out wire terminal 9. A common-line cathode terminal 11 is welded on the second conductive layer 201 of the second conductive film 2.

[0016] Solder pads 6 are respectively provided at two end faces of the micropore 4. The solder pads 6 cover the periphery of the micropore 4, and the thickness of the solder pads 6 is less than the thickness of the PDLC coating 3.

[0017] The cell 7 is square.

[0018] In this embodiment, the first conductive film 1 and the second conductive film 2 are made of ITO film.

[0019] A method for manufacturing a transparent flexible liquid crystal display film based on PDLC includes the following steps: A. Use a laser to etch a plurality of cells 7 of a certain size on the first conductive layer 101 of the first conductive film 1 ( Figure 1 Taking a 16*16 display module as an example), so as to form display cells.

[0020] B. Adopt mechanical punching or laser hole digging and other methods to form a through micropore 4 with a diameter of 0.2-0.3 mm on each cell 7. Pour a conductive paste 5 with a certain consistency into the micropore 4 for hole filling. After the conductive paste 5 is fully connected and cured with the first conductive layer 101, each cell 7 obtains a conductive channel.

[0021] C. Each conductive paste 5 filled in each micropore 4 is connected to a cell lead-out wire 8, and each cell lead-out wire 8 is connected to the lead-out wire terminal 9; if both sides of the first conductive film 1 have the first conductive layer 101, then the cell lead-out wire 8 is directly formed by laser etching on the first conductive layer 101 on the side where the cells 7 are not etched; if the first conductive film 1 has the first conductive layer 101 only on one side, then a transparent or low visibility conductive paste is screen-printed on the side of the first conductive film 1 without the first conductive layer 101 to form the cell lead-out wire 8. For the convenience of explanation, the cell 7 side lines and the cell lead-out wires 8 in the drawings are shown as solid lines, and the actual wire diameters are very small and difficult to see with the naked eye.

[0022] D. To ensure the reliability of the conductive paste 5 in the micro-holes 4 connecting the first conductive layer 101 and the external circuit, solder pads 6 are formed by screen printing on the two end faces of the micro-holes 4 respectively, ensuring that the solder pads 6 cover the periphery of the micro-holes 4. The thickness of the PDLC coating 3 is generally 20 microns, and the thickness of the solder pads 6 is 10 microns.

[0023] E. Cut the second conductive film 2 into the same size as the first conductive film 1. The surface of the second conductive layer 201 of the second conductive film 2 does not need to be treated, and only a common-line cathode terminal 11 needs to be welded.

[0024] F. Uniformly coat the PDLC coating 3 between the first conductive layer 101 and the second conductive layer 201, so that the first conductive film 1 and the second conductive film 2 are integrated into one body, forming a PDLC-based transparent flexible liquid crystal display film.

[0025] Display principle: The first conductive film 1 serves as the anode of the display cell, and the second conductive film 2 serves as the common-line cathode of all display cells. The PDLC coating 3 on some cells 7 of the transparent flexible liquid crystal display film of the present invention is transparent under current drive, forming a light-transmitting area, while the PDLC coating 3 on the cells 7 not driven by current is in a scattered state, forming a fogging area. In this way, the required characters and patterns are displayed through light and dark contrast, and a transparent flexible liquid crystal display film can be displayed on both the front and back sides through a control circuit.

[0026] Taking a 16*16 unit as an example, the cell lead-out wires 8 of the 1st to 16th cells 7 in the 01st to 16th columns on the first conductive film 1 are respectively connected to the lead-out terminal 9 and each corresponds to the corresponding terminal. All these terminals are connected to the positive electrode, and the common-line cathode terminal 11 on the second conductive film 2 is connected to the negative electrode (normally open). When any of the cells 7 needs to be transparent, the corresponding terminal is made conductive and the rest of the terminals are disconnected. For example, if the 2nd, 4th, 5th, and 7th display cells in the 02nd column need to be transparent, the 2nd, 4th, 5th, and 7th terminals in the 02nd column are made conductive and the rest of the terminals are disconnected. At this time, the current passes through the cell lead-out wires 8 of the 2nd, 4th, 5th, and 7th cells 7 in the 02nd column of the first conductive film 1 to reach the 2nd, 4th, 5th, and 7th cells 7 in the 02nd column, passes through the corresponding PDLC coating 3 to make it transparent, then enters the second conductive film 2, and then flows out from the common-line cathode terminal 11 on the second conductive film 2 to form a closed loop.

[0027] The following is an example to illustrate the display principle of displaying a "country" character with a 16*16 unit. Figure 6 It is the display state diagram of the "country" character.

[0028] As Figure 6As shown, at this time, cells 7 No. 1-16 in column 01 of the first conductive film 1 are in a powered (transparent) state; cells 7 No. 1 and 16 in columns 02 and 03 are in a powered (transparent) state; cells 7 No. 1, 3-13, 15, and 16 in column 04 are in a powered (transparent) state; cells 7 No. 1, 3, 4, 6-11, 13, 15, and 16 in column 05 are in a powered (transparent) state; cells 7 No. 1, 3, 4, 6, 7, 9-11, 13, 15, and 16 in columns 06 and 07 are in a powered (transparent) state; cells 7 No. 1, 3, 4, 13, 15, and 16 in columns 08 and 09 are in a powered (transparent) state. Status; in the 10th column, cells 1, 3, 4, 6, 7, 9-11, 13, 15, and 16, 7 are in the powered (transparent) state; in the 11th column, cells 1, 3, 4, 6, 7, 9, 11, 13, 15, and 16 are in the powered (transparent) state; in the 12th column, cells 1, 3, 4, 6-10, 13, 15, and 16 are in the powered (transparent) state; in the 13th column, cells 1, 3-11, 13, 15, and 16 are in the powered (transparent) state; in the 14th and 15th columns, cells 1 and 16 are in the powered (transparent) state; in the 16th column, cells 1-16 are in the powered (transparent) state.

[0029] In the circuit control, if binary code is used to control the opening and closing of the lead terminal 9, 0 represents closing and 1 represents opening, the code is as follows: Column 01 is 1111111111111111; Columns 02 and 03 are 1000000000000001; Column 04 is 1011111111111011; Column 05 is 1011011111101011; Columns 06 and 07 are 10110110111010 The 8th and 9th columns are 1011000000001011; the 10th column is 1011011011101011; the 11th column is 1011011010101011; the 12th column is 1011011111001011; the 13th column is 1011111111101011; the 14th and 15th columns are 100000000000001; and the 16th column is 1111111111111111. By controlling the opening and closing of the lead-out terminal 9 on the transparent flexible liquid crystal display film of the present invention, the character "国" (country) can be displayed.

Claims

1. A transparent flexible liquid crystal display film based on PDLC, characterized in that: It includes a transparent first conductive film (1) and a transparent second conductive film (2). The surface of the first conductive film (1) has a first conductive layer (101), and the surface of the second conductive film (2) has a second conductive layer (201). The first conductive layer (101) and the second conductive layer (201) are arranged oppositely, and a PDLC coating (3) is coated therebetween. Multiple cells (7) are etched on the first conductive layer (101) of the first conductive film (1). Each cell (7) is provided with a through micropore (4). The micropore (4) is filled with a conductive paste (5). Each conductive paste (5) filled in the micropore (4) is respectively connected with a cell lead-out wire (8). An lead-out wire terminal (9) is provided on the first conductive film (1), and each cell lead-out wire (8) is respectively connected to the lead-out wire terminal (9). A co-linear cathode terminal (11) is welded on the second conductive layer (201) of the second conductive film (2).

2. The transparent flexible liquid crystal display film based on PDLC according to claim 1, characterized in that: Pad (6) is respectively arranged on two end faces of the micropore (4). The pad (6) covers the outer periphery of the micropore (4), and the thickness of the pad (6) is less than the thickness of the PDLC coating (3).

3. A transparent flexible liquid crystal display film based on PDLC according to claim 1 or 2, characterized in that: The cell (7) is square.

4. A method for manufacturing a PDLC-based transparent flexible liquid crystal display film according to claim 2, characterized in that It includes the following steps: A. Use laser to etch multiple cells (7) on the first conductive layer (101) of the first conductive film (1). B. Form a through micropore (4) on each cell (7), pour the conductive paste (5) into the micropore (4) for hole filling. After the conductive paste (5) is fully connected and cured with the first conductive layer (101), each cell (7) obtains a conductive channel. C. The conductive paste (5) filled in each micropore (4) is connected with the cell lead-out wire (8), and each cell lead-out wire (8) is connected to the lead-out wire terminal (9). D. Pad (6) is respectively formed on two end faces of the micropore (4) by screen printing, ensuring that the pad (6) covers the outer periphery of the micropore (4). E. Weld a co-linear cathode terminal (11) on the surface of the second conductive layer (201) of the second conductive film (2). F. Coat a PDLC coating (3) between the first conductive layer (101) and the second conductive layer (201) to integrate the first conductive film (1) and the second conductive film (2) into a transparent flexible liquid crystal display film based on PDLC.

5. The manufacturing method of a transparent flexible liquid crystal display film based on PDLC according to claim 4, wherein: In step C, if both sides of the first conductive film (1) have the first conductive layer (101), then the cell lead-out wire (8) is directly formed by laser etching on the first conductive layer (101) of the side where the cells (7) are not etched; if only one side of the first conductive film (1) has the first conductive layer (101), then the transparent conductive paste is screen printed on the side of the first conductive film (1) without the first conductive layer (101) to form the cell lead-out wire (8).

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