Electronic paper screen and production method therefor

Abstract

Provided are an electronic paper screen and a production method therefor. The electronic paper screen comprises an electronic paper film and a thin film transistor substrate, which are sequentially arranged from a top end to a bottom end, wherein the electronic paper film is rectangular; a VCOM electrode is provided on the thin film transistor substrate; a VCOM ITO electrode is provided on the electronic paper film; the VCOM electrode and the VCOM ITO electrode are in communication by means of silver paste arranged between the thin film transistor substrate and the electronic paper film; the silver paste is strip-shaped, and is arranged on an edge of the end of the electronic paper film where a conduction zone between the VCOM electrode and the VCOM ITO electrode is located; the electronic paper film is configured to display an image; and the thin film transistor substrate is configured to drive and control pixels.

Description

Electronic paper screen and production method thereof

[0001] Related applications

[0002] This application claims priority to the Chinese invention patent application with application number 202310939177.7 filed on July 28, 2023, and cites the entire contents disclosed in the above patent application as part of this application. Technical Field

[0003] The present disclosure relates to the field of electronic technology, and in particular to an electronic paper screen and a production method thereof. Background Art

[0004] This section is intended to provide a background or context to the embodiments of the present disclosure that are recited in the claims. No admission is made that anything herein is prior art by virtue of its inclusion in this section.

[0005] An electronic paper screen is a display screen made using electrophoretic display technology. Specifically, a control circuit on a thin-film transistor (TFT) substrate applies a driving voltage to each pixel to display an image. As a reflective display, an electronic paper screen maintains the image for a long time after updating without requiring continuous refresh, resulting in very low power consumption. Due to its low power consumption, wide viewing angle, high contrast, and eye-friendly features, electronic paper screens are increasingly used in a variety of fields, including electronic price tags, e-books, and billboards.

[0006] To drive the VCOM ITO electrode on the front plane laminate (FPL) of the electronic paper screen, existing e-paper screens require ear holes in the FPL. Silver glue is then applied to the ear holes, and the VCOM electrode on the TFT substrate is then connected to the VCOM ITO electrode on the FPL using a dispensing method. The ear holes create irregular shapes for the FPL and PS protective film, increasing their size and TFT size. This not only widens the bezel and reduces the screen-to-body ratio of the e-paper screen, but also reduces the number of FPL, PS protective film, and TFTs cut, increasing material costs.

[0007] Summary of the Invention

[0008] The present disclosure provides an electronic paper screen for achieving a narrow frame and a high screen-to-body ratio of the electronic paper screen.

[0009] The electronic paper screen comprises: an electronic paper film and a thin film transistor substrate arranged in sequence from top to bottom; the electronic paper film is rectangular in shape;

[0010] A VCOM electrode is provided on the thin film transistor substrate, and a VCOM ITO electrode is provided on the electronic paper film;

[0011] The VCOM electrode and the VCOM ITO electrode are connected via a strip of silver glue between the thin film transistor substrate and the electronic paper film. The silver glue is located at the edge of one end of the electronic paper film where the conductive area between the VCOM electrode and the VCOM ITO electrode is located.

[0012] The electronic paper film is used to display images; and

[0013] The thin film transistor substrate is used to control pixel driving.

[0014] Furthermore, the electronic paper screen further includes: an integrated circuit IC and a flexible circuit board FPC; and the IC and the FPC are separately arranged on the thin film transistor substrate.

[0015] Furthermore, the FPC is used to transmit control commands and image data to the IC; the IC is used to process the control commands and image data and convert them into control timing of the thin film transistor substrate to display the image.

[0016] The present disclosure provides a method for producing an electronic paper screen, for achieving a narrow frame and a high screen-to-body ratio of the electronic paper screen. The method includes:

[0017] attaching the electronic paper film to the thin film transistor substrate;

[0018] Apply silver glue to the edge of one end of the electronic paper film where the conductive area between the VCOM electrode and the VCOM ITO electrode is located; the VCOM electrode is on the thin film transistor substrate, and the VCOM ITO electrode is on the electronic paper film;

[0019] Pre-curing the silver glue;

[0020] Soldering the integrated circuit IC to the thin film transistor substrate;

[0021] Soldering the flexible circuit board FPC to the thin film transistor substrate;

[0022] Attach the PS protective film to the electronic paper film;

[0023] Apply edge sealing glue to the edge of the PS protective film;

[0024] Use a vacuum temperature controlled furnace to cure and degas the silver glue and edge sealing glue; and

[0025] The bonding area of ​​the thin film transistor substrate is coated with silicone.

[0026] In an embodiment of the present disclosure, an electronic paper screen includes an electronic paper film and a thin-film transistor substrate, arranged sequentially from top to bottom. The electronic paper film is rectangular in shape. A VCOM electrode is provided on the thin-film transistor substrate, and a VCOM ITO electrode is provided on the electronic paper film. The VCOM electrode and the VCOM ITO electrode are connected via silver paste provided between the thin-film transistor substrate and the electronic paper film. The silver paste is strip-shaped and is provided at the edge of one end of the electronic paper film where the conductive area between the VCOM electrode and the VCOM ITO electrode is located. The electronic paper film is used to display images, and the thin-film transistor substrate is used to control pixel driving. Compared with the prior art, by providing silver paste at the edge of one end of the electronic paper film where the conductive area between the VCOM electrode and the VCOM ITO electrode is located, the conductive area of ​​the silver paste is effectively increased, thereby improving the driving capability of the VCOM ITO on the electronic paper film. Furthermore, the ear holes can be eliminated, and the outer shapes of the electronic paper film and the PS protective film are rectangularized, thereby significantly reducing the peripheral dimensions of the electronic paper film, the protective film, and the thin-film transistor, thereby achieving a narrow bezel, a high screen-to-body ratio, and a low cost for the electronic paper screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0028] FIG1 is a planar structural diagram of an electronic paper screen provided by an embodiment of the present disclosure;

[0029] FIG2 is a longitudinal cross-sectional view taken along the line AA′ in FIG1 according to an embodiment of the present disclosure;

[0030] FIG3 is a longitudinal cross-sectional view taken along the line AA′ in FIG1 according to an embodiment of the present disclosure;

[0031] FIG4 is a longitudinal cross-sectional view taken along the line AA′ in FIG1 according to an embodiment of the present disclosure;

[0032] FIG5 is a planar structural diagram of an electronic paper screen and an electronic paper film provided by an embodiment of the present disclosure;

[0033] FIG6 is a planar structural diagram of an electronic paper screen and an electronic paper film provided by an embodiment of the present disclosure;

[0034] FIG7 is a planar structural diagram of an electronic paper screen and an electronic paper film provided by an embodiment of the present disclosure;

[0035] FIG8 is a flow chart of a method for producing an electronic paper screen according to an embodiment of the present disclosure;

[0036] FIG9 is a flow chart of a method for producing an electronic paper screen according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0037] To make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the embodiments of the present disclosure are further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure, but are not intended to limit the present disclosure.

[0038] The acquisition, storage, use, and processing of data in this application's technical solution comply with relevant national laws and regulations.

[0039] The term "and / or" herein simply describes an association relationship, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, and the existence of B alone. In addition, the term "at least one" herein refers to any combination of at least two of any one or more of a plurality of items. For example, "at least one of A, B, and C" can represent any one or more elements selected from the set consisting of A, B, and C.

[0040] In the description of this specification, the terms "include", "including", "have", "contain", etc. are all open terms, which mean including but not limited to. The descriptions with reference to the terms "one embodiment", "a specific embodiment", "some embodiments", "for example", etc. mean that the specific features, structures or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. The order of steps involved in each embodiment is used to schematically illustrate the implementation of the present application, and the order of steps therein is not limited and can be appropriately adjusted as needed.

[0041] An electronic paper screen provided by an embodiment of the present disclosure includes an electronic paper film and a thin film transistor substrate arranged in sequence from top to bottom; and the electronic paper film is rectangular in shape.

[0042] It should be noted that the thin film transistor substrate includes a thin film transistor array and a glass substrate.

[0043] A VCOM electrode is provided on the thin film transistor substrate, and a VCOM ITO electrode is provided on the electronic paper film.

[0044] The VCOM electrode and the VCOM ITO electrode are connected through silver glue arranged between the thin film transistor substrate and the electronic paper film; the silver glue is in the shape of a strip; the silver glue is arranged at the edge of one end of the electronic paper film where the conductive area between the VCOM electrode and the VCOM ITO electrode is located.

[0045] Electronic paper films are used to display images.

[0046] The thin film transistor substrate is used to control pixel driving.

[0047] An electronic paper screen provided by an embodiment of the present disclosure also includes: a PS protective film and edge sealing glue arranged on the periphery of the PS protective film; the PS protective film covers the electronic paper film; and the PS protective film is rectangular in shape.

[0048] PS protective film is used to protect the electronic paper film and isolate water vapor.

[0049] Edge sealing glue is used to fill the gap between the PS protective film and the thin film transistor substrate to isolate water vapor.

[0050] An electronic paper screen provided by an embodiment of the present disclosure further includes: an integrated circuit IC (Integrated Circuits) and a flexible printed circuit FPC (Flexible Printed Circuit); in a possible implementation, the IC and the FPC are separately provided on a thin film transistor substrate.

[0051] In the embodiment of the present disclosure, the FPC is used to realize the electrical connection between the IC and the external circuit (i.e., the PCB (Printed circuit board) control circuit outside the electronic paper screen). The FPC acts as a connector to transmit the power signal, control commands, and image data of the external circuit to the IC. The IC processes the control commands and image data and converts them into the control timing of the TFT substrate to realize image display.

[0052] Figure 1 is a planar structural diagram of the electronic paper screen provided by an embodiment of the present disclosure. It can be seen from the figure that the PS protective film is rectangular in shape, the edge of the PS protective film is located outside the edge of the electronic paper film FPL and the edge of the silver glue Ag glue, and the PS protective film completely wraps the FPL and silver glue.

[0053] The FPL is rectangular in shape, completely covering the transition zone (Border) and active area (AA) of the thin-film transistor (TFT) substrate. A strip electrode area is provided on the lower edge of the FPL. Silver paste is applied to the edge of one end of the electronic paper film, where the conductive area between the VCOM electrode and the VCOM ITO electrode is located. The silver paste covers the entire FPL electrode area. The area of ​​the electrode area is the effective conductive area of ​​the silver paste. The lengths of the first and second sides of the silver paste are equal to the length of the side of the electronic paper film where the silver paste is applied. The silver paste is applied to the edge of the electronic paper film adjacent to the integrated circuit (IC) and the flexible circuit board (FPC).

[0054] The Border area is in the shape of a closed ring, the inner edge and the outer edge of the ring are in the shape of a rectangle, and the Border area surrounds the AA area; the AA area is in the shape of a rectangle.

[0055] The above solution, by placing silver glue at the edge of one end of the electronic paper film where the conductive area between the VCOM electrode and the VCOM ITO electrode is located, can not only effectively increase the conductive area of ​​the silver glue and improve the driving capability of the VCOM ITO on the electronic paper film, but also remove the ear holes and rectangularize the appearance of the electronic paper film and PS protective film, thereby greatly reducing the peripheral dimensions of the electronic paper film, protective film and thin-film transistor, thereby achieving a narrow bezel, high screen-to-body ratio and low cost for the electronic paper screen.

[0056] Figure 2 is a longitudinal cross-sectional view taken along line A-A' in Figure 1, according to an embodiment of the present disclosure. The figure illustrates the following: the distance a extends from the edge of the PS protective film beyond the edge of the Ag adhesive; edge-sealing adhesive is applied within the area where the PS protective film edge extends beyond the edge of the FPL. This adhesive bonds the edge of the PS protective film to the TFT substrate, preventing moisture from entering the FPL; the Ag adhesive is located at the edge of the FPL; the distance b from the outer edge of the Ag adhesive to the FPL edge, and the distance c from the inner edge of the Ag adhesive to the FPL edge, respectively.

[0057] The Ag paste is positioned corresponding to regions 1-1 and 1-2 on the TFT array, with region 1-1 located outside the edge of the FPL and region 1-2 located within the edge of the FPL. The first side of the Ag paste and a first portion of the upper surface adjacent to the first side are connected to the edge-sealing adhesive, while the second side of the Ag paste and a second portion of the upper surface adjacent to the second side are connected to the electronic paper film.

[0058] In a possible implementation, the area of ​​the first portion of the upper surface is half of the area of ​​the upper surface, and the area of ​​the second portion of the upper surface is half of the area of ​​the upper surface.

[0059] The area of ​​the first portion of the upper surface may also be one third of the area of ​​the upper surface, and the area of ​​the second portion of the upper surface may be two thirds of the area of ​​the upper surface. This embodiment of the present disclosure does not specifically limit this.

[0060] The TFT substrate has VCOM electrodes in areas 1-1 and 1-2. These electrodes are connected to the VCOM ITO on the FPL via Ag paste, providing a driving voltage for the VCOM ITO on the FPL. The bottom surface of the silver paste is connected to the VCOM electrode on the thin-film transistor substrate. The VCOM electrode area on the TFT array is the same as the Ag paste area.

[0061] In a possible implementation, the conductive area of ​​the silver paste is greater than 2π square millimeters.

[0062] Region 3 of the TFT array corresponds to the Border area of ​​the electronic paper screen, and the width of the Border area is e; Region 2 is set between region 1 (including 1-1 and 1-2) and region 3 of the TFT array, and the width of region 2 is d. Region 2 is used to isolate the Ag glue point and the Border area to prevent the Ag glue from accidentally overlapping with the ITO electrode in the Border area, and to prevent the FPL from entering the Border area due to edge damage caused by laser cutting at the Ag glue point.

[0063] Area 4 of the TFT array corresponds to the AA area, the active display area of ​​the e-paper screen. Areas 2 and 3 are located between Areas 1 and 4, separated by a distance of d + e. Areas 2 and 3 are used to isolate the Ag glue from the AA area to prevent the FPL from entering the AA area during use due to edge damage caused by laser cutting at the Ag glue.

[0064] In order to ensure that the electronic paper screen can still display normally under the conditions of maximum fluctuations in material properties, process capabilities and process, the size range requirements for a, b, c, d, and e are as follows: 1. 0.5mm≤a≤1mm; 2. 0mm <b≤1mm;3、0<c≤1mm;4、0.3mm≤d≤1mm;5、0mm≤e≤1mm。

[0065] Table 1 compares the conductive area of ​​Ag paste in the prior art and in the embodiment of the present disclosure. The effective conductive area of ​​a single strip-shaped edge Ag paste in the embodiment of the present disclosure is assumed to be L×W, where L is the horizontal length of the AA region and W is the width of the upper electrode region of the electronic paper film FPL.

[0066] Table 1 Effect of Ag paste shape and number on Ag paste conductive area

[0067] Comparing the conductive area of ​​Ag adhesive shows that when W is constant, due to the large L value, the area of ​​S3 is much larger than S1 and S2, so the strip-edge Ag adhesive has a larger conductive area and better conductivity. When the conductive area is constant (S3 = S1 or S3 = S2), due to the large L value, the W value will be very small, so the strip-edge Ag adhesive can achieve a smaller FPL size.

[0068] In a possible implementation, the area of ​​the VCOM electrode on the TFT array is larger than the area of ​​the Ag glue. As shown in FIG3 , the area of ​​the VCOM electrode on the TFT array includes and is larger than area 1 - 1 and area 1 - 2 .

[0069] In another possible embodiment, the VCOM electrode area on the TFT array is different from the area of ​​the Ag paste. As shown in Figure 4, the VCOM electrode area on the TFT array includes and is larger than Area 1-1 and does not overlap with Area 1-2. Half of the bottom surface of the Ag paste is connected to the VCOM electrode on the TFT substrate.

[0070] In the disclosed embodiment, multiple Ag pastes can be provided, with the silver paste being placed anywhere along the edge of one end of the electronic paper film, where the conductive area between the VCOM electrode and the VCOM ITO electrode is located. As shown in Figure 5, the left side shows a planar structural diagram of the electronic paper screen, and the right side shows a planar structural diagram of the FPL within the electronic paper screen.

[0071] In a possible implementation, two electrode regions are respectively disposed at the left and right ends of the lower edge of the FPL, and two strip-shaped Ag glues are disposed at the edges of the FPL corresponding to the electrode regions.

[0072] As shown in FIG6 , the left side is a planar structural diagram of the electronic paper screen, and the right side is a planar structural diagram of the FPL in the electronic paper screen.

[0073] In a possible implementation, two electrode regions are respectively disposed at the lower edges of the FPL, and two strip-shaped Ag glues are disposed at the edges of the FPL corresponding to the electrode regions.

[0074] As shown in FIG7 , the left side is a planar structural diagram of the electronic paper screen, and the right side is a planar structural diagram of the FPL in the electronic paper screen.

[0075] In one possible implementation, the electrode area is disposed on the upper edge of the FPL, and a strip of Ag glue is disposed on the FPL edge corresponding to the electrode area. The silver glue is disposed on the edge of the electronic paper film away from the integrated circuit IC and the flexible circuit board FPC.

[0076] As shown in FIG8 , the present disclosure further provides a method for producing an electronic paper screen, comprising:

[0077] S801, attaching the electronic paper film to the thin film transistor substrate.

[0078] S802 , coating silver paste on the edge of one end of the electronic paper film where the conductive area between the VCOM electrode and the VCOM ITO electrode is located.

[0079] It should be noted that the VCOM electrode is on the thin film transistor substrate, and the VCOM ITO electrode is on the electronic paper film.

[0080] S803, pre-curing the silver glue.

[0081] In the embodiment of the present disclosure, UV (Ultra-Violet) curing type Ag glue or heat curing type Ag glue is used, and UV light irradiation equipment or infrared light heat curing equipment is used for pre-curing.

[0082] S804, soldering the integrated circuit IC to the thin film transistor substrate.

[0083] S805 , welding the flexible circuit board FPC to the thin film transistor substrate.

[0084] S806, attaching the PS protective film to the electronic paper film.

[0085] In the embodiment of the present disclosure, after the PS protective film is attached to the electronic paper film, the steps are as shown in FIG9 , and are specifically as follows:

[0086] S901, apply edge sealing glue on the edge of the PS protective film.

[0087] S902: Use a vacuum temperature-controlled furnace to cure and degas the silver glue and edge sealing glue.

[0088] S903 , coating the bonding area of ​​the thin film transistor substrate with silicone.

[0089] In a possible implementation, in the Ag glue coating process, a dispensing needle with an inner diameter of 0.1 mm to 0.5 mm is selected for coating.

[0090] In order to better coat the Ag glue on the edge of the FPL, in one possible implementation, the angle between the needle and the TFT substrate is between 30 degrees and 60 degrees.

[0091] In a possible implementation, the Ag glue is coated by scribing.

[0092] In the above solution, the FPL is first attached to the TFT substrate, and then the Ag glue is applied, and the Ag glue needs to be pre-cured after the coating is completed. A narrower strip of Ag glue is achieved. By setting the silver glue at the edge of one end of the electronic paper film where the conductive area between the VCOM electrode and the VCOM ITO electrode is located, it can not only effectively increase the conductive area of ​​the silver glue and improve the driving ability of the VCOM ITO on the electronic paper film, but also remove the ear holes and rectangularize the shape of the electronic paper film and PS protective film, thereby greatly reducing the peripheral dimensions of the electronic paper film, protective film and thin film transistor, thereby achieving a narrow frame, high screen-to-body ratio and low cost of the electronic paper screen.

[0093] The above-mentioned specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the scope of protection of the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. An electronic paper screen, characterized in that: It includes an electronic paper film and a thin film transistor substrate which are sequentially arranged from the top to the bottom; wherein the shape of the electronic paper film is a rectangle; A VCOM electrode is provided on the thin film transistor substrate, and a VCOM ITO electrode is provided on the electronic paper film; The VCOM electrode and the VCOM ITO electrode are connected through a silver glue arranged between the thin film transistor substrate and the electronic paper film; the silver glue is in the shape of a strip; the silver glue is arranged at the edge of one end of the electronic paper film where the conduction area between the VCOM electrode and the VCOM ITO electrode is located; The electronic paper film is used to display images; and The thin film transistor substrate is used to control pixel driving.

2. The electronic paper screen according to claim 1, characterized in that: Also includes: A PS protective film and an edge-sealing adhesive arranged on the periphery of the PS protective film; wherein the PS protective film covers the electronic paper film; and the shape of the PS protective film is rectangular; PS protective film is used to protect the electronic paper film and isolate water vapor; and Edge sealing glue is used to fill the gap between the PS protective film and the thin film transistor substrate to isolate water vapor.

3. The electronic paper screen as claimed in claim 2, characterized in that: The first side surface of the silver glue and the first part of the upper surface adjacent to the first side surface are connected to the edge sealing glue; and the second side surface of the silver glue and the second part of the upper surface adjacent to the second side surface are connected to the electronic paper film.

4. The electronic paper screen according to claim 1, characterized in that: The conductive area of ​​silver paste is greater than 2π square millimeters.

5. The electronic paper screen according to claim 1, characterized in that: The bottom surface of the silver paste is connected to the VCOM electrode on the thin film transistor substrate.

6. The electronic paper screen as claimed in claim 3, characterized in that: The length of the first side surface of the silver glue and the length of the second side surface are equal to the length of one side of the electronic paper film where the silver glue is located.

7. The electronic paper screen according to claim 1, characterized in that: Also includes: An integrated circuit IC and a flexible circuit board FPC; and the IC and the FPC are separately arranged on a thin film transistor substrate.

8. The electronic paper screen according to claim 7, characterized in that: The FPC is used to transmit control commands and image data to the IC; and the IC is used to process the control commands and image data to convert the control commands and image data into control timings of the thin film transistor substrate to display images.

9. The electronic paper screen according to claim 7, characterized in that: The silver glue is arranged on the edge of one side of the electronic paper film adjacent to the integrated circuit IC and the flexible circuit board FPC.

10. A method for producing an electronic paper screen, characterized in that: include: attaching the electronic paper film to the thin film transistor substrate; Apply silver glue to the edge of one end of the electronic paper film where the conduction area between the VCOM electrode and the VCOM ITO electrode is located; The VCOM electrode is on the thin film transistor substrate, and the VCOM ITO electrode is on the electronic paper film; Pre-curing the silver glue; Soldering the integrated circuit IC to the thin film transistor substrate; Soldering the flexible circuit board FPC to the thin film transistor substrate; Attach the PS protective film to the electronic paper film; Apply edge sealing glue to the edge of the PS protective film; Use a vacuum temperature-controlled furnace to cure and degas the silver glue and edge-sealing glue; as well as The bonding area of ​​the thin film transistor substrate is coated with silicone.

Images