A film coating device and method for a curved liquid crystal display

Abstract

The application provides a film coating device and method for a curved liquid crystal display screen, comprising: a heating roller and a pressing roller arranged on a movable roller body support; one side of a film body is wound and stored on a feeding roller, the other side of the film body is sequentially arranged on the heating roller and the pressing roller, and a release film layer of the film body is wound and stored on a receiving roller; the maximum stroke length of the film body between the heating roller and the pressing roller is set as: L≤(K1-K2) / Q; wherein, L is the maximum stroke length of the film body between the heating roller and the pressing roller, Q is the average temperature reduction value of the heated film body per stroke length, K1 is the temperature of the film body heated by the heating roller, and K2 is the minimum temperature for maintaining the softening of the film body; the heating roller continuously heats the heat-deformed film layer corresponding to the part with a larger curvature of the curved screen to be coated. The application solves the problem of film body rebounding, peeling and warping after long-term use of the curved display screen with a larger curvature, and improves the curved screen coating effect of the roller pressing film coating process.

Description

Technical Field

[0001] This application relates to the field of curved display screen technology, and in particular to a coating apparatus and method for a curved liquid crystal display screen. Background Technology

[0002] Flexible OLED (Organic Light-Emitting Diode) technology is a technology that places light-emitting LEDs on a flexible substrate to emit light. Based on the deformable and bendable characteristics of flexible OLEDs, they are often used as light-emitting panels for curved displays of various sizes and shapes, such as small-sized curved smartphones and smartwatches, as well as foldable screen phones (with bending at the crease), and large-sized curved advertising displays, long ultrawide screens, and irregularly shaped displays for automobiles.

[0003] For curved screens or devices with curved screens, some manufacturers will pre-apply a protective film to the curved screens before they leave the factory. This can prevent scratches on the surface of these curved screens during the subsequent manufacturing process. Consumers can use them directly after purchase without having to buy a special protective film to apply it themselves. This is especially important for newly launched curved screen smartphones, as third-party protective film manufacturers need a certain period of time to develop molds and produce them.

[0004] Existing curved screen lamination processes mainly include finished film lamination and roll lamination. This document cites patent document CN106597711A, which discloses a curved screen lamination device and method. Specifically, the curved screen lamination device includes a fan-shaped rotating mechanism and a curved screen support component. The curved screen support component is arc-shaped. The fan-shaped rotating mechanism includes a rotating shaft and multiple telescopic rods. The rotating shaft is located inside the curved screen support component. One end of each telescopic rod is fixed at a different position on the same ring of the rotating shaft, and the other end of each telescopic rod is located at a different position on the same ring of the curved screen support component. The multiple telescopic rods can rotate in the same plane as the rotating shaft, thereby driving the curved screen support component to rotate around the rotating shaft. When the telescopic rods extend or retract, the radius of curvature of the curved screen support component increases or decreases accordingly. As can be seen, CN106597711A adjusts the extension and retraction of the telescopic rod to accommodate the radius of curvature of the curved portion of the screen to be coated. It utilizes a fan-shaped rotating mechanism, a lifting mechanism, and bonding rollers for film application, ensuring more thorough adhesion between the film and the curved screen during the rolling process. However, for displays with large curvatures, CN106597711A cannot solve the problem of partial rebound, detachment, and lifting after long-term use.

[0005] It should be noted that the information in the background section above includes selective and targeted illustrative descriptions based on this application. Therefore, the above is only used to enhance the understanding of the background technology of this application, and may include technical information that does not constitute technical information known or easily inferred by a person skilled in the art. Summary of the Invention

[0006] In view of the above problems, this application is made to provide a coating apparatus and method for a curved liquid crystal display screen that overcomes or at least partially solves the above problems.

[0007] This application discloses a coating apparatus for a curved liquid crystal display screen, used to cover a film onto a curved screen to be coated. The film includes a release film layer and a heat-softened heat-deformable film layer. The apparatus includes: a control component, a movable roller bracket, a feeding roller, a heating roller, a pressure roller, a receiving roller, and a curved screen support platform for mounting the curved screen to be coated. The heating roller includes at least one.

[0008] The heating roller and the pressure roller are mounted on the movable roller support; one side of the film is wound up and stored on the unloading roller, and the other side of the film is sequentially mounted on the heating roller and the pressure roller, with the release film layer of the film wound up and stored on the take-up roller; the maximum stroke length of the film between the heating roller and the pressure roller is set as follows:

[0009] L≤(K1-K2) / Q

[0010] Wherein, L is the maximum stroke length of the film between the heating roller and the pressure roller, Q is the average temperature drop of the heated film per unit stroke length, K1 is the temperature to which the film is heated by the heating roller, and K2 is the minimum temperature at which the film maintains thermal softening.

[0011] During the lamination process, the heating roller continuously heats the heat-deformable film layer corresponding to the portion of the curved screen to be laminated with a larger curvature; the control component drives the film to unwind and drives the movable roller support to make the pressure roller and the curved screen to be laminated come into contact and move relative to each other, and to make the heat-deformable film layer on the outside of the pressure roller adhere to the curved screen to be laminated.

[0012] Furthermore, the device also includes a first guide rail disposed on the top beam; the movable roller support includes: a first translation mechanism, a lifting mechanism, a main suspension and at least two cantilever arms;

[0013] The first translation mechanism is movably disposed on the first guide rail along the length direction of the first guide rail; one end of the lifting mechanism is connected to the first translation mechanism, and the other end of the lifting mechanism is connected to the main suspension.

[0014] The main suspension is connected to the cantilever, and the cantilever is rotatable and adjustable relative to the main suspension;

[0015] The heating roller and the pressure roller are respectively disposed on different cantilever arms; the cantilever arm where the pressure roller is located is disposed close to the curved screen support platform.

[0016] Furthermore, the heating rollers include at least two; the cantilever includes at least three; the first heating roller is disposed on the first cantilever; the second heating roller is disposed on the second cantilever; and the pressure roller is disposed on the third cantilever.

[0017] When the film is being coated, the first heating roller and the second heating roller are used to simultaneously and continuously heat the heat-deformable film layer corresponding to two parts of the same curved screen with larger curvature.

[0018] Furthermore, the first cantilever is provided with a guide groove for adjusting the position of the first heating roller; the second cantilever is provided with a guide groove for adjusting the position of the second heating roller.

[0019] Furthermore, the heating rollers include at least three; the third heating roller is disposed on the main suspension.

[0020] Furthermore, the curved screen support platform includes a second translation mechanism; the device also includes a second guide rail; the second translation mechanism is movably disposed on the second guide rail along the length direction of the second guide rail.

[0021] Furthermore, the heating rollers include at least two; and also include a heat-conducting tape; the heat-conducting tape surrounds and covers the at least two heating rollers.

[0022] Furthermore, the membrane body also includes a heat-shrinkable film layer that shrinks upon heating; the heat-shrinkable film layer is disposed on the side of the heat-deformable film layer away from the release film layer;

[0023] When laminating, the heating roller is used to continuously heat the heat-shrinkable film layer corresponding to the portion of the curved screen with a larger curvature to be laminated.

[0024] This application also discloses a coating method for a curved liquid crystal display screen, which is implemented by a coating apparatus for a curved liquid crystal display screen as described in any embodiment of this application;

[0025] The method includes:

[0026] S1. Install the curved screen to be covered onto the curved screen support platform;

[0027] S2. Position the surface of the curved screen to be covered and set the stroke of the pressure roller;

[0028] S3. Locate the portion of the curved screen to be covered with a large curvature to determine the installation position of the heating roller;

[0029] S4. The control component drives the film to unwind, performing one film feeding until the film is at the position corresponding to the heating roller;

[0030] S5. The heat-deformable film layer corresponding to the portion of the curved screen to be covered with a large curvature is continuously heated by the heating roller;

[0031] S6. The control component drives the film to unwind and perform secondary film feeding until the heated part of the film is at the position corresponding to the pressure roller;

[0032] S7. The control component drives the movable roller support and the unwinding of the film according to the stroke of the pressure roller, so that the pressure roller and the curved screen to be coated come into contact and move relative to each other, and the heat-deformable film layer on the outside of the pressure roller is bonded to the curved screen to be coated.

[0033] S8. The control component drives the movable roller support to reset;

[0034] S9. Cool the heat-deformation film layer and remove the finished display screen.

[0035] Furthermore, the heating rollers comprise at least two;

[0036] The step of locating the portion of the curved screen to be covered with a large curvature and determining the installation position of the heating roller includes:

[0037] Position at least two portions of the curved screen to be covered with a large curvature, and determine the installation positions of the at least two heating rollers accordingly.

[0038] This application has the following advantages:

[0039] In the embodiments of this application, compared to the existing roll-coating process which cannot solve the problem of partial rebound, delamination, and lifting of the film on curved displays with large curvature after long-term use, this application provides a solution in which a heating roller and a pressure roller are arranged on a movable roller support. The heating roller continuously heats and heats the heat-deformed film layer corresponding to the part of the curved display with large curvature to be coated. A control component drives the film to unwind and drives the movable roller support to perform coating. Specifically, the heating roller and the pressure roller are arranged on the movable roller support; one side of the film is wound up and stored on the unwinding roller, and the other side of the film is sequentially arranged on the heating roller and the pressure roller. The release film layer of the film is wound up and stored on the take-up roller; the heating roller and the pressure roller are arranged on the movable roller support. The maximum stroke length of the film between the pressure rollers is set as: L≤(K1-K2) / Q; where L is the maximum stroke length of the film between the heating roller and the pressure roller, Q is the average temperature decrease of the heated film per unit stroke length, K1 is the temperature reached by the heating roller, and K2 is the minimum temperature at which the film maintains thermal softening. During lamination, the heating roller continuously heats the heat-deformable film layer corresponding to the portion of the curved screen with a larger curvature to be laminated. The control component drives the film to unwind and drives the movable roller support to make the pressure roller and the curved screen to be laminated abut and move relative to each other, thus bonding the heat-deformable film layer on the outside of the pressure roller to the curved screen to be laminated. This application solves the problem of partial rebound, delamination, and lifting of the film in curved displays with large curvature after long-term use, and improves the curvature bonding effect of the roller lamination process. Attached Figure Description

[0040] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the first overall structure of a coating device for a curved liquid crystal display screen according to an embodiment of this application;

[0042] Figure 2 This is a second overall structural schematic diagram of a coating device for a curved liquid crystal display screen provided in one embodiment of this application;

[0043] Figure 3 This is a schematic diagram of the overall structure of the movable roller support in one embodiment of this application;

[0044] Figure 4 This is a schematic diagram of the structure of a convex curved screen and a concave curved screen in one embodiment of this application;

[0045] Figure 5This is a schematic diagram of the roller arrangement structure in one embodiment of this application when the curved screen to be covered is a mobile phone screen with both sides being arc-shaped.

[0046] Figure 6 This is a schematic diagram of the roller arrangement structure in one embodiment of this application when the curved screen to be covered is a foldable mobile phone screen with arc-shaped sides and a concave crease in the middle.

[0047] Figure 7 This is a schematic diagram of the roller arrangement structure in one embodiment of this application when the curved screen to be covered is a curved surface with a large overall curvature;

[0048] Figure 8 This is a schematic diagram of the roller arrangement structure in one embodiment of this application when the curved screen to be covered is a screen with a long horizontal dimension, or when the pressure roller and the heating roller are relatively close.

[0049] Figure 9 This is a schematic diagram of the roller arrangement structure in one embodiment of this application when the curved screen to be covered is a screen with a shorter horizontal dimension;

[0050] Figure 10 This is a schematic diagram of the first structure of the cantilever in one embodiment of this application;

[0051] Figure 11 This is a schematic diagram of the second structure of the cantilever in one embodiment of this application.

[0052] The attached figures are labeled as follows:

[0053] 1. Membrane body; 2. Curved screen to be coated; 3. Movable roller support; 30. Main suspension; 31. Cantilever; 311. First cantilever; 312. Second cantilever; 313. Third cantilever; 314. Guide groove; 33. First translation mechanism; 34. Lifting mechanism; 41. Heating roller; 411. First heating roller; 412. Second heating roller; 413. Third heating roller; 414. Heat conduction tape; 42. Pressure roller; 43. Feeding roller; 44. Receiving roller; 51. Curved screen support platform; 52. First guide rail; 53. Second guide rail. Detailed Implementation

[0054] To make the objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0055] The inventors discovered through analysis of existing technologies that current roll-coating processes cannot solve the problem of partial film rebound, detachment, and lifting after long-term use of curved displays with large curvature. The root cause is that existing roll-coating processes for curved screens only physically roll the film more thoroughly at the contact point between the bonding roller and the curved surface, without substantially changing the structure or performance of the film itself. As a result, the adhesive performance of the film gradually weakens after long-term use, while the purely physical rolling process leaves the elasticity and internal stress of the film itself intact. When the change in adhesive force reaches a certain threshold, the film will rebound, detach, and lift.

[0056] As a relative reference, the pre-finished film lamination process involves customized mold making, injection molding, hot bending or thermosetting, and cutting to produce individual pre-finished films. These films are then applied to curved screens manually or by machine. This method ensures a good fit between the pre-finished film and the curved screen, minimizing edge lifting. It's clear that the pre-finished film lamination process essentially pre-shapes the produced film, typically preventing additional internal stress during the lamination stage. However, the overall process of pre-finished film lamination is more complex and costly. Roll lamination, on the other hand, allows for direct lamination of roll-produced film without the need for cutting or repacking, simplifying the process and reducing costs. Since neither process can simultaneously achieve both high production efficiency and excellent lamination, pre-finished film lamination and roll lamination become difficult choices to make.

[0057] Based on the inventors' systematic analysis of the prior art, the core technical concept of this application is to improve the roll-coating process as follows: before roll-coating, the film is preheated and softened on a heating roller, and before the film is reheated and shaped, it is pressed onto a curved screen in time, and the film is finally cooled and shaped directly on the curved screen. The shaped film has a new stress state, and while retaining the advantages of low cost and high efficiency of the roll-coating process, the curved surface bonding effect of the film is also better.

[0058] Reference Figure 1-3 This application illustrates a coating apparatus for a curved liquid crystal display screen according to an embodiment of the present application. The apparatus is used to cover a curved screen 2 to be coated with a film 1. The film 1 includes a release film layer and a heat-softened heat-deformable film layer. The apparatus includes: a control component, a movable roller support 3, a feeding roller 43, a heating roller 41, a pressure roller 42, a receiving roller 44, and a curved screen support platform 51 for mounting the curved screen 2 to be coated. The heating roller 41 includes at least one.

[0059] The heating roller 41 and the pressure roller 42 are mounted on the movable roller support 3; one side of the film body 1 is wound up and stored on the unloading roller 43, and the other side of the film body 1 is sequentially mounted on the heating roller 41 and the pressure roller 42; the release film layer of the film body 1 is wound up and stored on the take-up roller 44; the maximum stroke length of the film body 1 between the heating roller 41 and the pressure roller 42 is set as follows:

[0060] L≤(K1-K2) / Q

[0061] Wherein, L is the maximum stroke length of the film 1 between the heating roller 41 and the pressure roller 42, Q is the average temperature drop of the heated film 1 per unit stroke length, K1 is the temperature to which the film 1 is heated by the heating roller 41, and K2 is the minimum temperature at which the film 1 maintains thermal softening.

[0062] When laminating, the heating roller 41 continuously heats the heat-deformable film layer corresponding to the part of the curved screen 2 with a larger curvature; the control component drives the film body 1 to unwind and drives the movable roller support 3 to make the pressure roller 42 and the curved screen 2 to be laminated come into contact and move relative to each other, and makes the heat-deformable film layer on the outside of the pressure roller 42 adhere to the curved screen 2 to be laminated.

[0063] In the embodiments of this application, compared to the existing roll-coating process which cannot solve the problem of partial rebound and peeling of the film 1 after long-term use of curved displays with large curvature, this application provides a solution in which a heating roller 41 and a pressure roller 42 are arranged on a movable roller support 3, the heating roller 41 continuously heats and heat-deforms the film layer corresponding to the part of the curved display 2 with large curvature to be coated, and the control component drives the film 1 to unwind and drives the movable roller support 3 to perform coating. Specifically, the heating roller 41 and the pressure roller 42 are arranged on the movable roller support 3; one side of the film 1 is wound up and stored on the unwinding roller 43, and the other side of the film 1 is sequentially arranged on the heating roller 41 and the pressure roller 42, and the release film layer of the film 1 is wound up and stored on the take-up roller 44; ... the heating roller 41 and the pressure roller 42 are arranged on the movable roller support 3; the heating roller 41 and the pressure roller 42 are arranged on the movable roller support 3; the heating roller 41 and the pressure roller 42 are arranged on the movable roller support 3; the heating roller 41 and the pressure roller 42 are arranged on the movable roller support 3; the heating roller 41 and the pressure roller 42 are arranged on the movable roller support 3; the heating roller 41 and the pressure roller 42 are arranged on the movable roller support 3; the heating roller 41 and the pressure roller 42 are arranged The maximum stroke length of the film 1 between the heating roller 41 and the pressure roller 42 is set as: L≤(K1-K2) / Q; where L is the maximum stroke length of the film 1 between the heating roller 41 and the pressure roller 42, Q is the average temperature reduction of the heated film 1 per unit stroke length, K1 is the temperature to which the film 1 is heated by the heating roller 41, and K2 is the minimum temperature at which the film 1 maintains thermal softening. When laminating, the heating roller 41 continuously heats the heat-deformable film layer corresponding to the part of the curved screen 2 with a larger curvature to be laminated. The control component drives the film 1 to unwind and drives the movable roller support 3 to make the pressure roller 42 and the curved screen 2 to be laminated abut and move relative to each other, and to make the heat-deformable film layer on the outside of the pressure roller 42 adhere to the curved screen 2 to be laminated. This application solves the problem of partial rebound, delamination and lifting of the film in curved displays with large curvature after long-term use, and improves the curvature bonding effect of the roller laminating process.

[0064] The coating apparatus for a curved liquid crystal display screen in this exemplary embodiment will now be further described.

[0065] It should be noted that the heat-deformable film layer may include a polyurethane-based film layer, the thickness of which may be 50μm-150μm, and the thickness of the release film layer may be 25μm-75μm. The heat-deformable film layer may be pre-processed with cutting marks to allow for release when attached to a curved screen. The heating roller 41 can heat from one side of the heat-deformable film layer or from one side of the release film layer, depending on the actual roller arrangement conditions during lamination. The heat softening process requires the film 1 to be continuously heated for a period of time (generally 4-8 seconds, depending on the temperature of the heating roller 41 and the substrate of the film 1).

[0066] Because the film 1 is relatively thin, to prevent excessive heat loss during the transfer of the film 1 from the heating roller 41 to the pressure roller 42, which would result in poor thermal softening, it is necessary to limit the maximum travel length of the film 1 between the heating roller 41 and the pressure roller 42. This ensures that the actual temperature of the film 1 when it is transferred to the pressure roller 42 is not lower than the minimum temperature at which the film 1 maintains thermal softening; that is, the actual temperature drop of the film 1 is not greater than the maximum allowable temperature drop at the current heating temperature. Therefore:

[0067] T1=L·Q≤K1-K2=T2

[0068] The following is a list:

[0069] L≤(K1-K2) / Q

[0070] Wherein, T1 is the actual temperature drop of the membrane 1, T2 is the maximum temperature drop allowed under the current heating temperature, L is the maximum stroke length of the membrane 1 between the heating roller 41 and the pressure roller 42, Q is the average temperature drop of the heated membrane 1 per unit stroke length, K1 is the temperature to which the membrane 1 is heated by the heating roller 41, and K2 is the minimum temperature at which the membrane 1 maintains thermal softening.

[0071] Since the heat loss is usually the greatest when the membrane 1 has traveled its maximum stroke, it is only necessary to measure the temperature drop of the heated part of the membrane 1 at its furthest point.

[0072] The average temperature drop Q per unit stroke length of the heated film 1 is a variable related to the ambient temperature, the material properties of the film 1, and the unwinding speed of the film 1. When actually arranging the heating rollers 41, an initial stroke length L0 of the film 1 can be predetermined. Then, the initial temperature drop T0 of the heated portion of the film 1 as it is transferred from the heating rollers 41 to the pressure rollers 42 can be measured. This allows for a rough estimation of the average temperature drop Q0 per unit stroke length of the heated film 1 under the current conditions.

[0073] Q0≈T0 / L0

[0074] test:

[0075] L0≤(K1-K2) / Q0

[0076] Then readjust the maximum stroke length L of the film 1 between the heating roller 41 and the pressure roller 42, where L is not greater than L0, and re-measure the actual temperature drop T1 of the heated part of the film 1. Calculate the average temperature drop Q of the heated film 1 per unit stroke length under the current condition, and we have:

[0077] Q=T1 / L

[0078] test:

[0079] L≤(K1-K2) / Q

[0080] If the conditions are met, the maximum stroke length L of the film 1 between the heating roller 41 and the pressure roller 42 can be determined, and the installation position of the heating roller 41 can be determined accordingly; if the conditions are not met, the maximum stroke length of the film 1 can be adjusted.

[0081] When measuring the actual temperature drop T1 of the heated part of the membrane 1, if the temperature of the heated part of the membrane 1 when it is transferred to the pressure roller 42 is not lower than the minimum temperature K2 at which the membrane 1 maintains thermal softening, Q can be determined directly without calculating Q. It should be understood that the role of Q is to describe the objective correspondence between the maximum stroke length L and the maximum allowable temperature drop T2 at the current heating temperature. The calculation of Q should be understood as a post-hoc method.

[0082] When there are multiple heating rollers 41, the temperature of each heating roller 41 can be adjusted adaptively to keep the temperature of the film 1 at the pressure roller 42 as consistent as possible during film coating. The size of each roller can be selected according to the actual shape and size of the curved screen, and the radius of the pressure roller 42 should not be greater than the minimum radius of curvature of the curved screen.

[0083] Both the heating roller 41 and the pressure roller 42 are mounted on the movable roller support 3, ensuring that the relative positions of the heating roller 41 and the pressure roller 42 remain constant. The tension of the film 1 at the pressure roller 42 is constant, guaranteeing that the tension of the film 1 at the pressure roller 42 will not change due to changes in the relative positions of the pressure roller 42 and the heating roller 41 during the film coating process, thus preventing accidental release of the film 1 and increasing the defect rate. There is also no need to add a tension roller between the heating roller 41 and the pressure roller 42 to avoid affecting the temperature of the film 1.

[0084] In continuous lamination scenarios, since the film 1 between the pressure roller 42 and its nearest heating roller 41 is not part of the current lamination, to avoid waste, as an example, the interval between the pressure roller 42 and the heating roller 41 can be optimized so that the interval can accommodate a film 1 the size of a curved screen. There is exactly one usable film 1 between each used segment of film 1, and the spacing and size of each usable film 1 are consistent, allowing for rewinding and reuse. Alternatively, the distance between the pressure roller 42 and its nearest heating roller 41 can be minimized, such as... Figure 8 As shown.

[0085] If some types of membrane 1 inherently possess the property of contracting upon cooling, such as... Figure 4 As shown at point A, in a scenario where a convex curved surface is covered, the membrane 1 can develop an elasticity with a tendency to contract, further conforming to the convex curved screen; as... Figure 4 As shown at point B, in the scenario of fitting a concave curved surface, the membrane 1 can be partially softened during the heating stage, retaining some of its elasticity. This elasticity can then be used to further fit the membrane 1 onto the concave curved screen.

[0086] The curved screen 2 to be covered described in this application may include, but is not limited to: mobile phone screens with curved sides, double-sided foldable mobile phone screens with a concave center, three-sided foldable mobile phone screens that include both convex and concave portions, large-size curved displays (such as curved ultrawide screens), and large-size automotive irregular-shaped displays.

[0087] In one embodiment of this application, the device further includes a first guide rail 52 disposed on the top beam; the movable roller support 3 includes: a first translation mechanism 33, a lifting mechanism 34, a main suspension 30 and at least two cantilever arms 31;

[0088] The first translation mechanism 33 is movably disposed on the first guide rail 52 along the length direction of the first guide rail 52; one end of the lifting mechanism 34 is connected to the first translation mechanism 33, and the other end of the lifting mechanism 34 is connected to the main suspension 30;

[0089] The main suspension 30 is connected to the cantilever 31, and the cantilever 31 is rotatable and adjustable relative to the main suspension 30;

[0090] The heating roller 41 and the pressure roller 42 are respectively disposed on different cantilever 31; the cantilever 31 where the pressure roller 42 is located is disposed close to the curved screen support platform 51.

[0091] It should be noted that the first translation mechanism 33 and the lifting mechanism 34 enable the movable roller support 3 to move as a whole along the surface of the curved screen 2 to be covered. By placing the heating roller 41 on the rotatable and adjustable cantilever 31, the position of the heating roller 41 can be easily adjusted during the pre-processing debugging process to determine the stroke of the film 1. The length and dimensions of the cantilever 31 can be selected according to the actual size of the curved screen 2 to be covered and the roller arrangement. The heating roller 41 can also be directly mounted on the main suspension 30.

[0092] In one embodiment of this application, the heating roller 41 includes at least two; the cantilever 31 includes at least three; the first heating roller 411 is disposed on the first cantilever 311; the second heating roller 412 is disposed on the second cantilever 312; and the pressure roller 42 is disposed on the third cantilever 313.

[0093] When the film is being coated, the first heating roller 411 and the second heating roller 412 are used to simultaneously and continuously heat the heat-deformable film layer corresponding to two parts of the same curved screen 2 with larger curvature.

[0094] As an example, refer to Figure 5The curved screen 2 to be covered is a mobile phone screen with both sides curved. When the heating roller 41 is laid out, the distance between the first heating roller 411 and the second heating roller 412 needs to be set to be consistent with the distance between the two curved edges of the curved screen 2 to be covered, so as to ensure that the heated part of the film 1 corresponds to the curved part of the curved screen 2 to be covered.

[0095] In one embodiment of this application, the first cantilever 311 is provided with a guide groove 314 for adjusting the position of the first heating roller 411; the second cantilever 312 is provided with a guide groove 314 for adjusting the position of the second heating roller 412.

[0096] It should be noted that, referring to Figure 10-11 The guide groove 314 of the cantilever 31 can be arranged along the length direction or along the rotation direction relative to the main suspension 30. The guide groove 314 can be used to accommodate multiple heating rollers 41.

[0097] In one embodiment of this application, the heating roller 41 includes at least three; the third heating roller 413 is disposed on the main suspension 30.

[0098] As an example, refer to Figure 6 The curved screen 2 to be covered is a foldable mobile phone screen with arc-shaped sides and a concave crease in the middle, that is, it includes three curved parts. When the heating rollers 41 are arranged, the third heating roller 413 can be directly set on the main suspension 30, and the first heating roller 411 and the second heating roller 412 can be respectively set on the two cantilever arms 31. The distance between the three heating rollers 41 is adjusted to ensure that the heated part of the film 1 corresponds to the curved part of the curved screen 2 to be covered.

[0099] Reference Figure 8 As an example, when the curved screen 2 to be covered is a screen with a long horizontal dimension, the travel length of the film 1 between the two heating rollers 41 can be increased by adjusting the position of the cantilever 31 or the heating roller 41 on the guide groove 314; as another example, the distance between the pressure roller 42 and the heating roller 41 can also be appropriately reduced to avoid waste of the film 1.

[0100] As an example, refer to Figure 9 When the curved screen 2 to be covered is a screen with a relatively short horizontal dimension, the two cantilever 31 can be set on the same side relative to the main suspension 30 to minimize the travel length of the film 1 between the two heating rollers 41.

[0101] In one embodiment of this application, the curved screen support platform 51 includes a second translation mechanism; the device also includes a second guide rail 53; the second translation mechanism is movably disposed on the second guide rail 53 along the length direction of the second guide rail 53.

[0102] It should be noted that the second translation mechanism can move back and forth along the length of the second guide rail 53. The two ends of the second guide rail 53 can also be used to connect machine tools for other processes, such as a curved screen production assembly machine tool at the front end, which can directly perform film coating after assembly, or an air blowing device for cooling and shaping the film 1 at the rear end, or the rear machine tool can perform secondary pressing of the film 1 through a mold that matches the shape of the curved screen, or the film 1 can be reinforced by UV lamp to enhance the shaping effect.

[0103] As an example, the curved screen support platform 51 may include several vacuum suction cups for stably adsorbing the back side of the curved screen 2 to be coated, preventing displacement during coating; the curved screen support platform 51 may also include a tilting mechanism for tilting the curved screen 2 to be coated to a certain extent to ensure full contact between the film 1 at the pressure roller 42 and the curved screen 2 to be coated.

[0104] Reference Figure 7 In one embodiment of this application, the heating roller 41 includes at least two; it also includes a heat-conducting tape 414; the heat-conducting tape 414 surrounds and covers the at least two heating rollers 41.

[0105] It should be noted that when the curved screen 2 to be covered has a large overall curvature, the at least two heating rollers 41 can be arranged side by side and covered with the heat-conducting tape 414. Since the rotation direction of each heating roller 41 is the same, a certain gap needs to be maintained between the heating rollers 41. Since the heat-conducting tape 414 rotates together with the at least two heating rollers 41, the heat-conducting tape 414 is heated evenly and fully, ensuring that the part of the film 1 in contact with the heat-conducting tape 414 is also heated evenly.

[0106] In one embodiment of this application, the film 1 further includes a heat-shrinkable film layer that shrinks upon heating; the heat-shrinkable film layer is disposed on the side of the heat-deformable film layer away from the release film layer;

[0107] When laminating, the heating roller 41 is used to continuously heat the heat-shrinkable film layer corresponding to the part of the curved screen 2 with a larger curvature.

[0108] It should be noted that the heat-shrinkable film layer can bend and deform the film 1 in a fixed direction after being heated, so that the side of the heat-shrinkable film layer can directly contact the heating roller 41 to enhance the heat-shrink effect.

[0109] The above is a description of the device embodiments of this application. For relevant aspects of the method embodiments of this application, please refer to the description of the corresponding parts of the device embodiments.

[0110] One embodiment of this application discloses a coating method for a curved liquid crystal display screen, wherein the method is implemented by a coating apparatus for a curved liquid crystal display screen as described in any embodiment of this application;

[0111] The method includes:

[0112] S1. Install the curved screen 2 to be covered onto the curved screen support platform 51;

[0113] S2. Position the surface of the curved screen 2 to be covered and set the stroke of the pressure roller 42;

[0114] S3. Locate the portion of the curved screen 2 to be covered with a large curvature and determine the installation position of the heating roller 41;

[0115] S4. The control component drives the film body 1 to unwind, and performs one film feeding until the film body 1 is at the position corresponding to the heating roller 41;

[0116] S5. The heat-deformable film layer corresponding to the part of the curved screen 2 to be covered with a larger curvature is continuously heated by the heating roller 41;

[0117] S6. The control component drives the film body 1 to unwind and perform secondary film feeding until the heated part of the film body 1 is at the position corresponding to the pressure roller 42.

[0118] S7. The control component drives the movable roller support 3 and the film 1 to unwind according to the stroke of the pressure roller 42, so that the pressure roller 42 and the curved screen to be covered 2 abut and move relative to each other, and the heat-deformable film layer on the outside of the pressure roller 42 is bonded to the curved screen to be covered 2.

[0119] S8. The control component drives the movable roller support 3 to reset;

[0120] S9. Cool the heat-deformation film layer and remove the finished display screen.

[0121] In one embodiment of this application, the heating roller 41 includes at least two;

[0122] The specific process of "positioning the portion of the curved screen 2 with a large curvature to determine the installation position of the heating roller 41" in step S110 can be further explained in conjunction with the following description:

[0123] As described in the following steps, at least two portions of the curved screen 2 to be covered with a larger curvature are positioned, and the installation positions of the at least two heating rollers 41 are determined accordingly.

[0124] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0125] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0126] The above provides a detailed description of the coating apparatus and method for a curved liquid crystal display screen provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, those skilled in the art will have changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A coating apparatus for a curved liquid crystal display screen, used to cover a curved screen to be coated with a film, characterized in that, The film body includes a release film layer and a heat-softened heat-deformable film layer; the device includes: a control component, a movable roller support, a feeding roller, a heating roller, a pressure roller, a receiving roller, and a curved screen support platform for mounting the curved screen to be coated; the heating roller includes at least one; The heating roller and the pressure roller are mounted on the movable roller support; one side of the film is wound up and stored on the unloading roller, and the other side of the film is sequentially mounted on the heating roller and the pressure roller, with the release film layer of the film wound up and stored on the take-up roller; the maximum stroke length of the film between the heating roller and the pressure roller is set as follows: L≤(K1-K2) / Q Wherein, L is the maximum stroke length of the film between the heating roller and the pressure roller, Q is the average temperature drop of the heated film per unit stroke length, K1 is the temperature to which the film is heated by the heating roller, and K2 is the minimum temperature at which the film maintains thermal softening. During the lamination process, the heating roller continuously heats the heat-deformable film layer corresponding to the portion of the curved screen with a larger curvature; the control component drives the film to unwind and drives the movable roller support to make the pressure roller and the curved screen to be laminated come into contact and move relative to each other, and to make the heat-deformable film layer on the outside of the pressure roller adhere to the curved screen to be laminated. The device also includes a first guide rail disposed on the top beam; the movable roller support includes: a first translation mechanism, a lifting mechanism, a main suspension and at least two cantilever arms; The first translation mechanism is movably disposed on the first guide rail along the length direction of the first guide rail; one end of the lifting mechanism is connected to the first translation mechanism, and the other end of the lifting mechanism is connected to the main suspension. The main suspension is connected to the cantilever, and the cantilever is rotatable and adjustable relative to the main suspension; The heating roller and the pressure roller are respectively disposed on different cantilever arms; the cantilever arm where the pressure roller is located is located close to the curved screen support platform; The heating rollers include at least two; the cantilever includes at least three; the first heating roller is disposed on the first cantilever; the second heating roller is disposed on the second cantilever; the pressure roller is disposed on the third cantilever; When laminating, the first heating roller and the second heating roller are used to simultaneously and continuously heat the heat-deformable film layer corresponding to two parts of the same curved screen with larger curvature. The first cantilever is provided with a guide groove for adjusting the position of the first heating roller; the second cantilever is provided with a guide groove for adjusting the position of the second heating roller.

2. The apparatus according to claim 1, characterized in that, The heating rollers include at least three; the third heating roller is disposed on the main suspension.

3. The apparatus according to claim 1, characterized in that, The curved screen support platform includes a second translation mechanism; the device also includes a second guide rail; the second translation mechanism is movably disposed on the second guide rail along the length direction of the second guide rail.

4. The apparatus according to claim 1, characterized in that, The heating rollers include at least two; and also include a heat-conducting tape; the heat-conducting tape surrounds and covers the at least two heating rollers.

5. The apparatus according to claim 1, characterized in that, The membrane also includes a heat-shrinkable film layer that shrinks upon heating; the heat-shrinkable film layer is disposed on the side of the heat-deformable film layer away from the release film layer; When laminating, the heating roller is used to continuously heat the heat-shrinkable film layer corresponding to the portion of the curved screen with a larger curvature to be laminated.

6. A coating method for a curved liquid crystal display screen, characterized in that, The method is implemented using a coating apparatus for a curved liquid crystal display screen as described in any one of claims 1-5; The method includes: S1. Install the curved screen to be covered onto the curved screen support platform; S2. Position the surface of the curved screen to be covered and set the stroke of the pressure roller; S3. Locate the portion of the curved screen to be covered with a large curvature to determine the installation position of the heating roller; S4. The control component drives the film to unwind, performing one film feeding until the film is at the position corresponding to the heating roller; S5. The heat-deformable film layer corresponding to the portion of the curved screen to be covered with a large curvature is continuously heated by the heating roller; S6. The control component drives the film to unwind and perform secondary film feeding until the heated part of the film is at the position corresponding to the pressure roller; S7. The control component drives the movable roller support and the unwinding of the film according to the stroke of the pressure roller, so that the pressure roller and the curved screen to be coated come into contact and move relative to each other, and the heat-deformable film layer on the outside of the pressure roller is bonded to the curved screen to be coated. S8. The control component drives the movable roller support to reset; S9. Cool the heat-deformation film layer and remove the finished display screen.

7. The method according to claim 6, characterized in that, The heating rollers include at least two; The step of locating the portion of the curved screen to be covered with a large curvature and determining the installation position of the heating roller includes: Position at least two portions of the curved screen to be covered with a large curvature, and determine the installation positions of the at least two heating rollers accordingly.

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