Method of forming middle frame, manufacturing method of folding display device, and printing device

Abstract

The application relates to the technical field of folding display, in particular to a middle frame forming method, a folding display device manufacturing method and a display device. The middle frame forming method of the folding display device comprises the following steps: providing a printing base; the printing base comprises a back plate, a display module and a cover plate; the printing base comprises an edge area; the edge area comprises a folding area and a non-folding area; the folding area is in a bending state when the display device is in a folding state; the non-folding area is part of the edge area except the folding area; printing the middle frame, comprising the following steps: printing a middle frame non-folding part in the non-folding area by using a 3D printing mode; printing a middle frame folding part in the folding area by using a 3D printing mode; the application can effectively solve the problems of screen loosening, poor waterproofness and dustproofness after long-term use of the folding display device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of foldable display, in particular to a middle frame forming method, a foldable display device manufacturing method and a printing device. BACKGROUND

[0002] With the development of display technology, the shape of display screen appears more and more forms. In particular, foldable screen, in the field of smart phones, becomes a widely used product. The display device of foldable screen, especially the smart phone of foldable screen, has two use states of folding state and unfolding state when in use. After long-term use, the screen is prone to loosen, and the waterproof and dustproof effect is not ideal. This is because, for the foldable display device, the mainstream middle frame is a metal middle frame, which is connected with the screen by adhesive. The metal middle frame has a certain degree of process error in manufacturing, so it is difficult to achieve complete adhesion with the screen, and then the screen is prone to loosen after long-term use, and the waterproof and dustproof effect is not ideal. Moreover, the metal middle frame is prone to irreversible deformation after being subjected to physical impact, which further causes the above problems. The metal middle frame has sharp edges, which can easily damage the screen during assembly. In addition, the metal middle frame also has the problems of complex process, low production efficiency and high cost.

[0003] Therefore, a scheme is needed to solve the problems of screen looseness, poor waterproof and dustproof effect after long-term use, screen damage during assembly, and low production efficiency and high cost caused by the metal middle frame of the foldable display device. SUMMARY

[0004] Therefore, in order to solve the problems of screen looseness, poor waterproof and dustproof effect after long-term use, screen damage during assembly, and low production efficiency and high cost caused by the metal middle frame of the foldable display device, the present application provides a middle frame forming method of foldable display device and a manufacturing method of foldable display device.

[0005] The present application provides a middle frame forming method of foldable display device, comprising the following steps: providing a printing base; the printing base comprises a back plate, a display module and a cover plate; the printing base comprises an edge area, the edge area comprises the edges of the back plate, the display module and the cover plate, and the areas from the edges to the center part of the printing base of the back plate, the display module layer and the cover plate; the edge area comprises a folding area and a non-folding area, the folding area is in a bending state when the display device is in a folding state, and the non-folding area is a part of the edge area except the folding area; printing the middle frame, comprising: using 3D printing method to print the non-folding part of the middle frame in the non-folding area; using 3D printing method to print the folding part of the middle frame in the folding area.

[0006] Optionally, the middle frame folding part comprises a plurality of parallel and spaced prismatic structures, forming a middle frame folding part with a toothed structure; the length extension direction of the prismatic structure is perpendicular to the side of the display device.

[0007] Optionally, the step of printing the middle frame folding part in the folding area using a 3D printing method comprises: using the print head of the 3D printer to print a plurality of prismatic structures on one side surface of the folding area in sequence, in parallel and at intervals, until the spacing between the currently printed prismatic structure and the nearest non-folding area is less than the width of one prismatic structure.

[0008] Optionally, the spacing between each prismatic structure is greater than half the width of the prismatic structure and less than the width of one prismatic structure.

[0009] Optionally, the method for forming the middle frame of the display device further comprises: printing a folding area frame bottom on one side surface of the folding area; the folding area frame bottom completely covers the folding area; and the prismatic structures are printed on the folding area frame bottom.

[0010] Optionally, the sum of the thickness of the folding area frame bottom and the height of the prismatic structure is equal to the thickness of the non-folding part of the middle frame; the longitudinal cross-sectional shape of the prismatic structure comprises a rectangle or a triangle; and each vertex of the longitudinal cross-sectional shape of the prismatic structure is a sharp corner or a rounded corner.

[0011] Optionally, the step of printing the middle frame folding part in the folding area using a 3D printing method comprises: using the print head of the 3D printer to print a plurality of prismatic structures on one side surface of the folding area in sequence, in parallel and at intervals, until the spacing between the currently printed prismatic structure and the nearest non-folding area is less than the width of one prismatic structure; using the print head of the 3D printer to print a plurality of prismatic structures on the surface of the back plate side of the folding area in sequence, in parallel and at intervals, until the spacing between the currently printed prismatic structure and the nearest non-folding area is less than the width of one prismatic structure; the midline of the spacing area between the prismatic structures on one side of the cover plate corresponds to the midline of the prismatic structures on one side of the back plate one by one; and the midline of the spacing area between the prismatic structures on one side of the back plate corresponds to the midline of the prismatic structures on one side of the cover plate one by one.

[0012] Optionally, the method further comprises: printing a front folding area frame bottom on a side surface of the cover plate of the folding area; the front folding area frame bottom completely covers the folding area; each ridge structure formed on the side surface of the cover plate is printed on the front folding area frame bottom; printing a back folding area frame bottom on a side surface of the back plate of the folding area; the back folding area frame bottom completely covers the folding area; each ridge structure formed on the side surface of the cover plate is printed on the back folding area frame bottom.

[0013] Optionally, the step of printing the middle frame further comprises: the 3D printing mode comprises 3D printing using a 3D printer; the 3D printer comprises a first printing head and a second printing head; the first printing head and the second printing head use different printing glue respectively; the 3D printer further comprises a scanning unit and a path calculation unit; the scanning unit scans the shape of the printing base to obtain shape data; the path calculation unit calculates the printing path of the first printing head and the second printing head according to the shape data; the first printing head is used to print an inner retaining wall along the inner edge of the edge area according to the calculated printing path; the first printing head is used to print an outer retaining wall along the outer edge of the edge area; a boundary retaining wall is printed along the boundary line of the non-folding area and the folding area; the second printing head is used to print a filling layer in the non-folding area according to the calculated printing path, the filling layer fills the space in the non-folding area defined by the inner retaining wall, the outer retaining wall and the boundary retaining wall; the second printing head is used to print the middle frame folding part in the folding area according to the calculated printing path.

[0014] Optionally, the first printing head prints a first glue, and the second printing head prints a second glue; the viscosity of the first glue is greater than the viscosity of the second glue; the first glue has shape retention, and the second glue has flowability.

[0015] Optionally, the 3D printing mode comprises one or more of direct writing printing, piezoelectric valve printing, striker valve printing and inkjet printing.

[0016] The application further provides a manufacturing method of a folding display device, and a middle frame of the folding display device is formed by the method.

[0017] The present invention also provides a printing apparatus suitable for 3D printing a printing substrate to form a mid-frame; the printing apparatus includes: a stage suitable for supporting the printing substrate; a printing unit suitable for printing mid-frame material within the edge area of ​​the printing substrate; the printing unit includes at least two print heads suitable for printing different materials respectively, one of which is suitable for forming an overflow wall in the non-folded area and a prismatic structure in the folded area of ​​the mid-frame; the other is suitable for forming a filling layer that fills the space enclosed by the overflow wall; a support suitable for mounting the printing unit; a scanning unit suitable for scanning the shape of the printing substrate and acquiring shape data; a path calculation unit suitable for receiving the data acquired by the scanning unit and calculating a printing route; and a driving unit suitable for driving the support to move according to the printing route provided by the path calculation unit, thereby moving the scanning unit and the printing unit.

[0018] The beneficial effects of the technical solution of this invention are as follows:

[0019] The present invention provides a method for forming the mid-frame of a foldable display device. In the folding and non-folding areas of the edge region, different shaped folded and non-folded mid-frame portions are formed by 3D printing. The foldable display mid-frame formed in this way, through 3D printing, achieves a tighter bond with the back panel or cover plate compared to a metal mid-frame bonded with adhesive. This results in higher bonding strength, reducing screen loosening after long-term use, and improving waterproof and dustproof performance. It also minimizes the decline in waterproof and dustproof performance over time, maintaining high levels of waterproof and dustproof capabilities. This further overcomes the problems of screen loosening and inadequate waterproof and dustproof performance caused by metal mid-frames in foldable display devices after long-term use. Furthermore, since the mid-frame is formed using 3D printing, a metal mid-frame is unnecessary, thus avoiding screen damage during assembly and the problems of low production efficiency and high cost. In addition, the present invention also provides a method for forming a foldable display device incorporating the mid-frame forming method of the present invention and a printing apparatus for its application, to achieve the aforementioned beneficial effects.

[0020] Furthermore, the method for forming the mid-frame of the foldable display device provided by the present invention includes a folded mid-frame comprising a plurality of parallel and spaced-apart prismatic structures, forming a folded mid-frame with a toothed structure. This folded mid-frame, with gaps between the prismatic structures, acts as a buffer when the solid structure is tightened during folding, reducing the mutual compression force on the solid structure during folding, thus reducing structural wear and tear and minimizing wear after long-term use. This further overcomes the problems of screen loosening and inadequate waterproofing and dustproofing caused by the metal mid-frame in foldable display devices after long-term use.

[0021] Further, the folding display device middle frame forming method provided by the present application is characterized in that the interval between each ridge-shaped structure is greater than half the width of the ridge-shaped structure and less than the width of one ridge-shaped structure. If the interval is too small, the ridge-shaped structures will be pressed against each other when the display device is in the folded state, which will easily cause use fatigue. If the interval is too large, the ridge-shaped structures will not be perfectly fitted when the display device is in the folded state, which will not be good for support and protection.

[0022] Further, the folding display device middle frame forming method provided by the present application is characterized in that the thickness of the folding area frame bottom and the height of the ridge-shaped structure are equal to the thickness of the non-folding part of the middle frame, so that the overall height of the middle frame in the folding area and the non-folding area is the same, the shape is beautiful, and the overall height consistency of the middle frame is ensured, which prevents the middle frame from being raised in some positions due to inconsistent height in subsequent process.

[0023] Further, the folding display device middle frame forming method provided by the present application is characterized in that when the design of the middle frame needs to cover the display device on both sides, the middle line of the interval area between the ridge-shaped structures on one side of the cover plate corresponds to the middle line of the ridge-shaped structures on one side of the back plate one by one, and the middle line of the interval area between the ridge-shaped structures on one side of the back plate corresponds to the middle line of the ridge-shaped structures on one side of the cover plate one by one. In this way, the stress points can be more dispersed when bending, the stress is more uniform, and the wear and the aforementioned corresponding defects caused by long-term use can be avoided, which can effectively prolong the service life of the middle frame. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0025] Figure 1 is a top view schematic diagram of the middle frame formed by the folding display device middle frame forming method of the present application;

[0026] Figure 2 is a top view schematic diagram of the middle frame formed by the folding display device middle frame forming method of an embodiment of the present application;

[0027] Figure 3 is a top view schematic diagram of the folding area after forming the folding part of the middle frame in the folding display device middle frame forming method of an embodiment of the present application;

[0028] Figures 4-7 is a longitudinal sectional view schematic diagram of the folding area after forming the folding part of the middle frame in the folding display device middle frame forming method of different embodiments of the present application;

[0029] Figure 8 A flowchart of a method for forming a middle frame of a folding display device according to an embodiment of the present application;

[0030] Figure 9 A flowchart of a printing middle frame step in a method for forming a middle frame of a folding display device according to an embodiment of the present application;

[0031] Figure 10 A flowchart of a printing middle frame step in a method for forming a middle frame of a folding display device according to another embodiment of the present application;

[0032] Figure 11 A structural diagram of a printing device according to an embodiment of the present application.

[0033] 100-printing base; 200-middle frame; 211-inner barrier wall; 212-outer barrier wall; 213-division barrier wall; 220-filling layer; 230-middle frame folding part; 231-folding area frame bottom; 232-prismatic structure; 2311-front folding area frame bottom; 2321-front prismatic structure; 2312-back folding area frame bottom; 2322-back prismatic structure; 310-carrier; 320-bracket; 331-first printing head; 332-second printing head; A-printing base. DETAILED DESCRIPTION

[0034] Reference Figure 1 A folding display device after a middle frame forming method according to an embodiment of the present application is shown in FIG. 1. It includes a printing base 100 and a middle frame 200. The printing base includes a back plate, a display module and a cover plate arranged in layers. The middle frame formed in this way is usually a metal middle frame. After long-term use, the screen is loose, waterproof and dustproof are not ideal, and the screen is easy to be damaged during assembly. The metal middle frame itself also has the problems of low production efficiency and high cost. Figure 1

[0035] Therefore, the present application provides a middle frame forming method of a folding display device and a manufacturing method of a folding display device to overcome the problems of screen looseness after long-term use, poor waterproof and dustproof, screen damage during assembly, low production efficiency and high cost of folding display devices caused by metal middle frames.

[0036] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0037] ​In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] In addition, the technical features involved in the different embodiments of the application described below can be combined with each other as long as there is no conflict between them.

[0040] Embodiment 1

[0041] Reference Figure 8 And Figure 2 、 Figure 3 、 Figure 4 The present embodiment provides a method for forming a middle frame of a folding display device, comprising the following steps:

[0042] S100: providing a printing base 100; the printing base 100 comprises a back plate, a display module and a cover plate arranged in layers; the printing base comprises an edge area, which comprises the edge of the back plate, the edge of the display module and the edge of the cover plate, and the area from the edge to the center part of the width of the printing base; the edge area comprises a folding area and a non-folding area, the folding area is in a bent state when the display device is in a folded state, and the non-folding area is part of the edge area other than the folding area;

[0043] S200: printing the middle frame 200, comprising:

[0044] S210: using a 3D printing method to print the middle frame non-folding part in the non-folding area;

[0045] S220: using a 3D printing method to print the middle frame folding part 230 in the folding area.

[0046] The folding display device frame forming method provided by the embodiment forms the middle frame folding part 230 and the middle frame non-folding part with different shapes in the folding area and the non-folding area of the edge area by 3D printing. The folding display device frame formed in this way has a higher bonding strength than the bonding of the metal middle frame by adhesive, so that the degree of screen loosening after long-term use can be reduced, and the waterproof and dustproof performance is better. The degree of decline in waterproof and dustproof performance after long-term use can also be reduced, and a higher waterproof and dustproof performance is maintained. Since the middle frame is formed by 3D printing, the metal middle frame is not used, so that the screen can be prevented from being easily damaged during assembly, and the problems of low production efficiency and high cost can be avoided.

[0047] The middle frame folding part 230 includes a plurality of parallel and spaced prismatic structures 232, forming a middle frame folding part 230 with a toothed structure; the length extension direction of the prismatic structure 232 is perpendicular to the edge of the display device where the prismatic structure 232 is located. In this way, when the display device is folded, the length direction of the prismatic structure is perpendicular to the folding direction of the display device and parallel to the crease direction, and will not hinder the folding of the display device. In addition, such a middle frame folding part 230 has a space between the prismatic structures, which acts as a buffer when the solid structure part (such as the prismatic structure 232) is tightened during folding, so that the mutual extrusion force of the solid structure part during folding is reduced, the structural wear is reduced, and the wear of the solid structure part after long-term use can be reduced. Further overcome the problem of screen loosening after long-term use of the folding display device caused by the metal middle frame, and the problem of unsatisfactory waterproof and dustproof performance.

[0048] Specifically, as shown in the figure, the middle frame folding part 230 is located at the long edge of the display device, so the prismatic structure 232 is also located at the long edge of the display device, and the length extension direction of the prismatic structure 232 is perpendicular to the long edge of the display device where the prismatic structure 232 is located. In other embodiments, the folding area is located at the short edge of the display device, and accordingly, the middle frame folding part 230 is also located at the short edge of the display device, and at this time, the length extension direction of the prismatic structure 232 is perpendicular to the short edge of the display device where the prismatic structure 232 is located.

[0049] In addition, the folding area and the corresponding middle frame folding part 230 shown in the figure are located near the center line of the display device, and in other embodiments, they can also be located at other positions, which are determined by the specific position of the folding line of the folding display device, and the present application is not limited thereto.

[0050] Specifically, referring to Figure 9 , the step S220 of printing the middle frame folding part in the folding area by using 3D printing includes:

[0051] S222: using the print head of the 3D printer, printing a plurality of ridge structures 232 on one side surface of the folding area in sequence and at intervals and in parallel until the spacing between the currently printed ridge structure 232 and the nearest non-folding area is less than the width of one ridge structure. According to the pre-set printing path, the ridge structures 232 arranged at intervals and in parallel can ensure the structural accuracy of the folding area of the middle frame.

[0052] More specifically, the spacing between each ridge structure 232 is greater than half the width of the ridge structure 232 and less than the width of one ridge structure 232. If the spacing is too small, the display device in the folded state will have each ridge structure 232 pressed against each other, which will easily increase the wear and tear. If the spacing is too large, the display device in the folded state will not be able to perfectly fit between each ridge structure 232, and the supporting and protecting effect will be poor.

[0053] Further, also referring to Figure 9 , and Figure 4 , the method for forming the middle frame of the display device of the embodiment further comprises:

[0054] S221: printing a folding area frame bottom 231 on one side surface of the folding area; the folding area frame bottom 231 completely covers the folding area; and the ridge structures 232 are printed on the folding area frame bottom. Due to the complete coverage of the folding area by the folding area frame bottom 231, the printing of the folding area frame bottom 231 is closely combined with the printing base of the folding area, so as to ensure the waterproof and dustproof performance of the folding part 230 of the middle frame in the folding area, and prevent the problem of reduced waterproof and dustproof performance caused by the gap between the ridge structures 232 arranged at intervals.

[0055] Further, the sum of the thickness of the folding area frame bottom 231 and the height of the ridge structure 232 is equal to the thickness of the non-folding part of the middle frame; in this way, the overall height of the middle frame in the folding area and the non-folding area is the same, the shape is beautiful, and the overall height consistency of the middle frame is ensured, preventing partial position warping due to inconsistent height of the middle frame in subsequent process.

[0056] In addition, referring to Figure 4 and Figure 5 , the longitudinal cross-sectional shape of the ridge structure 232 includes a rectangle or a triangle; different longitudinal cross-sectional shapes can be selected according to the shape of the folding part of the middle frame required when the folding display device is in the folded state. In addition, each corner of the longitudinal cross-sectional shape of the ridge structure 232 can be a sharp corner or a rounded corner, i.e., a special-shaped rectangle or triangle.

[0057] Further, referring to Figure 10 and Figure 6 and Figure 7In some other embodiments, the step S220 of printing the middle frame folding part in the folding area by using 3D printing comprises:

[0058] S2221: using the print head of the 3D printer, printing multiple front ridge structures 2321 on the surface of the cover plate side of the folding area in sequence, interval and parallel, until the interval between the currently printed front ridge structure 2321 and the nearest non-folding area is less than the width of one ridge structure;

[0059] S2222: using the print head of the 3D printer, printing multiple back ridge structures 2322 on the surface of the back plate side of the folding area in sequence, interval and parallel, until the interval between the currently printed back ridge structure 2322 and the nearest non-folding area is less than the width of one ridge structure;

[0060] The middle line of the interval area between the ridge structures on the cover plate side (i.e. front ridge structure 2321) corresponds to the middle line of the ridge structures on the back plate side (i.e. back ridge structure 2322); the middle line of the interval area between the ridge structures on the back plate side corresponds to the middle line of the ridge structures on the cover plate side.

[0061] In this way, when the design of the middle frame needs to cover the display device on both sides, the middle frame folding part 230 can be formed on both sides of the display device to meet the folding requirement, so that the stress point is more dispersed when bending, the stress is more uniform, and the long-term use can be avoided. The wear and the corresponding defects can be avoided, and the service life of the middle frame can be effectively prolonged.

[0062] Further, with reference to Figure 10 and Figure 6 and Figure 7 In some other embodiments, the method for forming the middle frame of the display device comprises the following steps:

[0063] S2211: printing a front folding area frame bottom 2311 on the surface of the cover plate side of the folding area; the front folding area frame bottom 2311 completely covers the folding area; each ridge structure (i.e. front ridge structure 2321) printed on the cover plate side is printed on the front folding area frame bottom 2311;

[0064] S2212: printing a back folding area frame bottom 2312 on the surface of the back plate side of the folding area; the back folding area frame bottom 2312 completely covers the folding area; each ridge structure (i.e. back ridge structure 2322) printed on the cover plate side is printed on the back folding area frame bottom 2312.

[0065] Thus, the folding area frame bottom is formed on the front and back of the display device, which can ensure that the folding area on the front and back is provided with a tightly combined middle frame, thereby ensuring the waterproof and dustproof effect of this area from the front and back.

[0066] Further, in the embodiment, the 3D printer comprises a first printing head and a second printing head; the first printing head and the second printing head use different printing glue respectively; the 3D printer further comprises a scanning unit and a path calculation unit;

[0067] The scanning unit scans the shape of the printing base to obtain shape data;

[0068] The path calculation unit calculates the printing path of the first printing head and the second printing head according to the shape data;

[0069] The first printing head is used to print an inner retaining wall 211 along the inner edge of the edge area according to the calculated printing path; the first printing head is used to print an outer retaining wall 212 along the outer edge of the edge area; a boundary retaining wall 213 is printed along the boundary line of the non-folding area and the folding area;

[0070] The second printing head is used to print a filling layer 220 in the non-folding area according to the calculated printing path, the filling layer 220 filling the space in the non-folding area defined by the inner retaining wall 211, the outer retaining wall 212 and the boundary retaining wall 213;

[0071] The second printing head is used to print the middle frame folding part in the folding area according to the calculated printing path.

[0072] Through the cooperation of the scanning unit, the path calculation unit and the printing head, the middle frame non-folding part and the middle frame folding part are formed, which can make the structure of each part of the formed middle frame accurately meet the design and highly meet the design requirements, thereby providing accurate performance guarantee.

[0073] Further, the first printing head prints the first glue, and the second printing head prints the second glue; the viscosity of the first glue is greater than that of the second glue; the first glue has shape retention, and the second glue has flowability; according to the different viscosity properties of the glue, the anti-overflow wall and the filling layer 220 are printed respectively, and different glues are printed by selecting different printing heads, which can make the final molding effect better and the printing smoother.

[0074] Preferably, the viscosity of the first glue is 1000000cps-2000000cps; the viscosity of the second glue is 50cps-500cps.

[0075] In addition, the middle frame forming method of the embodiment can be adapted to different 3D printing methods. In different embodiments, the 3D printing method in the step of printing the middle frame includes one or more of direct writing printing, piezoelectric valve printing, hammer valve printing, and inkjet printing.

[0076] Embodiment 2

[0077] The embodiment provides a manufacturing method of a folding display device, and a middle frame of the folding display device is formed by the middle frame forming method of the folding display device provided in Embodiment 1.

[0078] The manufacturing method of the folding display device provided in the embodiment forms the middle frame by the middle frame forming method of the folding display device provided in the embodiment. The folding area and the non-folding area of the edge area are respectively formed into different shapes of the middle frame folding part and the middle frame non-folding part by 3D printing. The middle frame folding part includes a plurality of prismatic structures arranged in parallel and at intervals, and forms a middle frame folding part with a toothed structure. The folding display middle frame formed in this way is more tightly combined with the back plate or the cover plate by 3D printing than the metal middle frame combined by adhesive bonding, and has higher bonding strength, so that the degree of screen loosening after long-term use can be reduced, and the waterproof and dustproof performance is better. In addition, the degree of decline in waterproof and dustproof performance after long-term use can be reduced, and the waterproof and dustproof performance can be maintained at a high level. In addition, such a middle frame folding part has intervals between the prismatic structures, and the part acts as a buffer when the solid structure part (such as the prismatic structure) is tightened during folding, so that the mutual extrusion force of the solid structure part during folding is reduced, the structural wear is reduced, and the wear of the solid structure part after long-term use can be reduced. Further, the problems of screen loosening and unsatisfactory waterproof and dustproof performance of the folding display device after long-term use caused by the metal middle frame are overcome. At the same time, since the middle frame is formed by 3D printing, the metal middle frame is not used, so that the screen is not easily damaged during assembly, and the problems of low production efficiency and high cost are avoided.

[0079] Embodiment 3

[0080] The embodiment provides a printing device suitable for 3D printing a middle frame on a printing base. Referring to Figure 11 , the printing device comprises:

[0081] a carrier 310 suitable for carrying the printing base A;

[0082] a printing unit suitable for printing middle frame material in the edge area of the printing base; the printing unit comprises at least two printing heads suitable for printing different materials respectively, one of which is suitable for forming the anti-overflow wall of the non-folding area and the prismatic structure of the folding area of the middle frame; and the other is suitable for forming a filling layer filling the space surrounded by the anti-overflow wall;

[0083] Specifically, the two print heads include a first print head 331 and a second print head 332 as shown in Figure 11 adapted to print different materials (e.g. different printing glue) respectively, the first print head 331 prints the anti-overflow wall of the non-folded area and the prismatic structure of the folded area of the middle frame, and the second print head 332 prints the filling layer filling the space surrounded by the anti-overflow wall.

[0084] a support 320 adapted to mount the print unit;

[0085] a scanning unit (not shown in the figure) adapted to scan the shape of the print substrate A to obtain shape data;

[0086] a path calculation unit (not shown in the figure) adapted to receive the data obtained by the scanning unit to calculate the printing path;

[0087] a driving unit (not shown in the figure) adapted to drive the support to move according to the printing path provided by the path calculation unit to drive the scanning unit and the print unit to move.

[0088] The printing device provided by the embodiment can apply the middle frame forming method of the folding display device of the above-mentioned embodiment 1 or the manufacturing method of the folding display device of the above-mentioned embodiment 2 to manufacture the corresponding middle frame or folding display device to obtain the corresponding beneficial effects.

[0089] Obviously, the above-mentioned embodiments are only examples for clear illustration, and are not limitations to the embodiments. Based on the above-mentioned description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to enumerate all the embodiments. The changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for forming the middle frame of a foldable display device, characterized in that, Includes the following steps: A printing substrate is provided; the printing substrate includes a back plate, a display module, and a cover plate; the printing substrate includes an edge region, which is the edge of the back plate, the edge of the display module, and the edge of the cover plate, and the area of ​​the back plate, the display module, and the cover plate extending from the edge to the center of the printing substrate; the edge region includes a folded region and a non-folded region, the folded region being bent when the display device is in a folded state, and the non-folded region being the portion of the edge region excluding the folded region; Using 3D printing, the non-folded portion of the frame is printed in the non-folded area; Using 3D printing, the folded portion of the frame is printed in the folded area; The folded portion of the middle frame includes several parallel and spaced-apart prismatic structures to form a folded portion of the middle frame with a toothed structure; the length extension direction of the prismatic structure is perpendicular to the side of the display device in which it is located. The step of printing the folded portion of the frame in the folded area using 3D printing includes: Using the print head of a 3D printer, multiple prismatic structures are sequentially and parallelly printed on one side surface of the folded area until the distance between the currently printed prismatic structure and the nearest unfolded area is less than the width of one of the prismatic structures.

2. The method for forming the middle frame of the foldable display device according to claim 1, characterized in that, The spacing between each of the prisms is greater than half the width of the prism and less than the width of one of the prisms.

3. The method for forming the middle frame of the foldable display device according to claim 1, characterized in that, Also includes: A folding area frame bottom is printed on one side surface of the folding area; the folding area frame bottom completely covers the folding area; the prismatic structure is printed on the folding area frame bottom.

4. The method for forming the middle frame of the foldable display device according to claim 3, characterized in that, The sum of the thickness of the bottom of the folded area frame and the height of the prismatic structure is equal to the thickness of the non-folded portion of the middle frame; The longitudinal cross-sectional shape of the prismatic structure includes a rectangle or a triangle; each vertex of the longitudinal cross-sectional shape of the prismatic structure is a sharp angle or a rounded angle.

5. The method for forming the middle frame of the foldable display device according to claim 1, characterized in that, The step of printing the folded portion of the frame in the folded area using 3D printing includes: Using the print head of a 3D printer, multiple front prism structures are sequentially and parallelly printed on the surface of one side of the cover plate of the folded area until the distance between the currently printed front prism structure and the nearest non-folded area is less than the width of one of the prism structures. Using the print head of a 3D printer, multiple back prism structures are sequentially and parallelly printed on the surface of the back plate side of the folded area until the distance between the currently printed back prism structure and the nearest non-folded area is less than the width of one of the prism structures. The centerline of the interval region between the prismatic structures on one side of the cover plate corresponds one-to-one with the centerline of the prismatic structure on one side of the back plate; the centerline of the interval region between the prismatic structures on one side of the back plate corresponds one-to-one with the centerline of the prismatic structure on one side of the cover plate.

6. The method for forming the middle frame of the foldable display device according to claim 5, characterized in that, Also includes: A front folding area frame bottom is printed on one side surface of the cover plate of the folding area; the front folding area frame bottom completely covers the folding area; the various prismatic structures printed on one side of the cover plate are printed on the front folding area frame bottom; A back folding area frame bottom is printed on one side surface of the back plate of the folding area; the back folding area frame bottom completely covers the folding area; the prismatic structures printed on one side of the cover plate are printed on the back folding area frame bottom.

7. The method for forming the middle frame of the folding display device according to any one of claims 1-6, characterized in that, The step of printing the middle frame also includes: The 3D printing method includes using a 3D printer for 3D printing; the 3D printer includes a first print head and a second print head; the first print head and the second print head use different printing adhesives respectively; the 3D printer also includes a scanning unit and a path calculation unit; The scanning unit scans the shape of the printing substrate to obtain shape data; The path calculation unit calculates the printing paths of the first print head and the second print head based on the shape data; Using the first printhead, an inner retaining wall is formed by printing along the inner edge of the edge area according to the calculated printing path; an outer retaining wall is formed by printing along the outer edge of the edge area using the first printhead; and a boundary retaining wall is formed by printing along the boundary line between the non-folded area and the folded area. Using the second printhead, a filling layer is printed in the non-folded area according to the calculated printing path. The filling layer fills the space in the non-folded area defined by the inner retaining wall, the outer retaining wall, and the dividing retaining wall. The second printhead is used to print the folded portion of the middle frame within the folded area according to the calculated print path.

8. The method for forming the middle frame of the foldable display device according to claim 7, characterized in that, The first print head prints the first adhesive, and the second print head prints the second adhesive. The viscosity of the first adhesive is greater than that of the second adhesive; the first adhesive has shape retention properties, while the second adhesive has fluidity.

9. The method for forming the middle frame of the display device according to claim 1, characterized in that, The 3D printing methods include one or more of the following: direct writing printing, piezoelectric valve printing, impactor valve printing, and inkjet printing.

10. A method for manufacturing a foldable display device, characterized in that, The mid-frame of the foldable display device is formed by the mid-frame forming method of the foldable display device as described in any one of claims 1-9.

11. A printing apparatus, adapted to be used in the method for forming the middle frame of a foldable display device as described in any one of claims 1-9, for 3D printing a printing substrate to form a middle frame, characterized in that, The printing device includes: A stage suitable for supporting the printing substrate; A printing unit is adapted to print a middle frame material within the edge region of the printing substrate; the printing unit includes at least two print heads adapted to print different materials respectively, one of which is adapted to form an overflow wall in the non-folded area of ​​the middle frame and a prismatic structure in the folded area; the other is adapted to form a filling layer that fills the space enclosed by the overflow wall; A bracket suitable for mounting the printing unit; The scanning unit is adapted to scan the shape of the printed substrate and acquire shape data; A path calculation unit is adapted to receive data acquired by the scanning unit and calculate the printing route. The driving unit is adapted to drive the support to move according to the printing route provided by the path calculation unit, so as to drive the scanning unit and the printing unit to move.

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