Device for testing bending of flexible material

Abstract

The invention provides a testing device for bending of a flexible material. The testing device comprises a fixed plate, a rotating plate and a tension unit, a supporting cambered surface is arranged at the end part of the fixing plate; the rotating plate is hinged to the end, provided with the supporting arc face, of the fixing plate. The tension unit is slidably connected with the rotating plate; in the testing process of the flexible material, one end of the flexible material is fixedly connected with the fixing plate, the other end of the flexible material is fixedly connected with the tension unit, the flexible material can be driven by the rotating plate to be bent, and in the bending process, the tension unit provides stretching pre-tightening force for the flexible material, so that the middle of the flexible material is kept in contact with the supporting cambered surface of the fixing plate; and further testing the limit bending radius of the flexible material. According to the flexible material bending testing device provided by the embodiment of the invention, the middle part of the flexible material is kept in contact with the supporting cambered surface of the fixed plate, so that the limit bending radius of the flexible material is tested, and the testing device has the characteristics of simple structure and accurate and stable measurement result.

Description

Technical Field

[0001] This application relates to the technical field of flexible material bending tests, and specifically relates to a test device for bending flexible materials. Background Art

[0002] As an important application technology of OLED, flexible screens have been significantly developed in recent years. Compared with traditional screens, flexible screens have significant advantages, such as being thinner and lighter in volume, having lower power consumption, and due to their bendable and flexible characteristics, the application scenarios of flexible screens are becoming more and more extensive. The flexible screen itself is a very thin flexible light-emitting layer. In product applications, it relies on a structure with a certain stiffness to be convenient for users to use. For a mobile terminal with bending characteristics, the deformation process of its flexible screen is the movement process of a deformable mechanism. For a book-style flexible screen terminal product that realizes unfolding / closing by folding in half, in terms of structure, the bending of the flexible screen needs to rely on a rigid housing and a bendable hinge mechanism. The two half-housings are connected by a hinge mechanism; the hinge mechanism has a stable structure at a specific angle, can rotate and bend when needed, and has a relatively smooth movement trajectory on the flexible screen side. The flexible screen follows the deformation of the housing and the hinge mechanism to achieve changes in the bent and flattened states.

[0003] With the development trend of folding machines towards being thinner and lighter, the miniaturized design of the rotating shaft continuously reduces the bending radius of the folding screen. The reduction of the bending radius generally leads to an increase in the stress of the inner stack and panel of the folding screen, and there is an increased risk of screen rupture during bending or dropping. Therefore, it is particularly important to test the bending strength of the screen to obtain the ultimate bending radius of the folding screen. The test results directly affect the design of the screen bending profile and the rotating shaft, and thus affect the design of the entire machine. However, in the prior art, there are only test devices related to bending life, and there is no related test device for bending ultimate strength. Summary of the Invention

[0004] The embodiment of this application provides a test device for bending flexible materials. The test device includes:

[0005] A fixed plate with a supporting arc surface at its end;

[0006] A rotating plate hinged to one end of the fixed plate where the supporting arc surface is provided;

[0007] A tension unit slidably connected to the rotating plate;

[0008] During the test of the flexible material, one end is fixedly connected to the fixed plate, and the other end is fixedly connected to the tension unit, and it can be bent under the drive of the rotating plate. During the bending process, the tension unit provides the tensile pre-tightening force for the flexible material, so that the middle part of the flexible material remains in contact with the supporting arc surface of the fixed plate, and then the ultimate bending radius of the flexible material is tested.

[0009] The test device for bending the flexible material provided by the embodiment of the present application designs a structure of a tension unit. During the test of the flexible material, one end is fixedly connected to the fixed plate, and the other end is fixedly connected to the tension unit, and it can be bent under the drive of the rotating plate. During the bending process, the tension unit provides the tensile pre-tightening force for the flexible material, so that the middle part of the flexible material remains in contact with the supporting arc surface of the fixed plate, and then the ultimate bending radius of the flexible material is tested. This test device has the characteristics of simple structure, accurate and stable measurement results. Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0011] Figure 1a It is a schematic diagram of the flattened state of the folding screen test in the conventional technical solution;

[0012] Figure 1b is Figure 1a a schematic diagram of the structure of the folding screen test in the semi-folded state in

[0013] Figure 1c is Figure 1a a schematic diagram of the structure of the folding screen test in the 180-degree folding state in

[0014] Figure 2 It is a schematic diagram of the overall structure of an embodiment of the test device for bending the flexible material of the present application;

[0015] Figure 3 is Figure 2 a schematic diagram of the partial structure of the test device in the embodiment;

[0016] Figure 4 is Figure 2 a schematic diagram of the side view structure of the test device in the embodiment;

[0017] Figure 5 is Figure 2 a schematic diagram of the sectional structure of the test device in the embodiment;

[0018] Figure 6It is a schematic structural diagram of a bending state of a flexible material during the test;

[0019] Figure 7 It is a schematic structural diagram of another bending state of a flexible material during the test;

[0020] Figure 8 It is a schematic structural diagram of an embodiment of the support arc surface of the present application;

[0021] Figure 9 It is a schematic structural diagram of an embodiment of the support arc surface of the present application;

[0022] Figure 10 It is Figure 9 a schematic cross-sectional structure diagram of the support arc surface in

[0023] Figure 11 It is a schematic structural diagram of another embodiment of the tension element of the present application;

[0024] Figure 12 It is a schematic structural diagram of a 180-degree bending state of the flexible material of the present application during the test. Detailed implementation manners

[0025] The following will further describe the present application in detail in conjunction with the drawings and embodiments. It should be specifically noted that the following embodiments are only used to illustrate the present application, but do not limit the scope of the present application. Similarly, the following embodiments are only partial embodiments of the present application rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0026] The terms "first", "second", and "third" in the embodiments of the present application are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly. The terms "including" and "having" in the embodiments of the present application and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include steps or units not listed, or may optionally further include other steps or components inherent to these processes, methods, products, or devices.

[0027] As used herein, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of the present application. The phrase may appear in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0028] As used herein, an "electronic device" (or simply "terminal") includes, but is not limited to, a device configured to receive / send communication signals via a wired connection (such as via a Public Switched Telephone Network (PSTN), Digital Subscriber Line (DSL), digital cable, direct cable connection, and / or another data connection / network) and / or via a wireless interface (such as for a cellular network, Wireless Local Area Network (WLAN), digital television network such as a DVB-H network, satellite network, AM-FM broadcast transmitter, and / or another communication terminal). A communication terminal configured to communicate via a wireless interface may be referred to as a "wireless communication terminal", "wireless terminal", or "mobile terminal". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; Personal Communication System (PCS) terminals that can combine cellular radiotelephone with data processing, facsimile, and data communication capabilities; PDAs that may include radiotelephones, pagers, Internet / intranet access, web browsers, memo pads, calendars, and / or Global Positioning System (GPS) receivers; and conventional laptop and / or palmtop receivers or other electronic devices including radiotelephone transceivers. A mobile phone is an electronic device configured with a cellular communication module.

[0029] Please refer to Figures 1a to 1c , Figure 1a is a schematic diagram of the flattened state of the folding screen test in the conventional technical solution, Figure 1b is Figure 1a a schematic structural diagram of the semi-folded state of the folding screen test in Figure 1c is Figure 1a a schematic structural diagram of the 180-degree folded state of the folding screen test in . Currently, for the folding screen 10a on the market, or the bending test of the flexible material inside the screen, generally, both ends of the material to be tested are fixed by two clamping plates (10b and 10c). When the clamping plates rotate to be parallel, the material to be tested forms a U-shaped form. Then, by reducing the distance between the clamping plates, the bending radius at which the material fails is obtained. The disadvantage of this method is that the bending radius of the flexible material is naturally formed by the parallel clamping plates and is strongly related to the stiffness of the flexible material (material, thickness, lamination design). The bending radii of the flexible materials formed with the same clamping plate distance are different, and the ultimate bending radius cannot be directly calculated through the plate distance, while there are large measurement errors when measuring with a microscope.

[0030] In view of this, for the test of the bending strength of flexible materials or flexible screens (which can be used in electronic devices such as mobile phones), the embodiments of the present application provide a test device for bending flexible materials. Please refer to Figures 2 to 4 , Figure 2 which is the overall structural schematic diagram of an embodiment of the test device for bending flexible materials of the present application, Figure 3 and Figure 2 is the partial structural schematic diagram of the test device in the embodiment, Figure 4 and Figure 2 is the side view structural schematic diagram of the test device in the embodiment; the test device for bending flexible materials in this embodiment includes but is not limited to the following structures: a fixed plate 100, a rotating plate 200, and a tension unit 300.

[0031] Specifically, a support arc surface 110 is provided at the end of the fixed plate 100, and the rotating plate 200 is hinged to one end of the fixed plate 100 where the support arc surface 110 is provided. Please refer to Figure 5 , Figure 5 which Figure 2 is the cross-sectional structural schematic diagram of the test device in the embodiment. Among them, the tension unit 300 is slidably connected to the rotating plate 200. During the test of the flexible material 88, one end is fixedly connected to the fixed plate 100 (specifically, it can be bonded, fixed by a clamping member, etc., and no specific limitation is made here), and the other end is fixedly connected to the tension unit 300 (similarly, it can also be bonded, fixed by a clamping member, etc.), and can be bent under the drive of the rotating plate 200.

[0032] Please refer to Figure 6 and Figure 7 , Figure 6 which is the structural schematic diagram of a bending state of the flexible material during the test, Figure 7 and is the structural schematic diagram of another bending state of the flexible material during the test; during the bending process, the tension unit 300 provides the tensile pre-tightening force of the flexible material 88, so that the middle part of the flexible material 88 remains in contact with the support arc surface 110 of the fixed plate 100, and then the ultimate bending radius of the flexible material 88 is tested.

[0033] Among them, the support arc surface 110 can be a single radius. Please refer to Figure 8 , Figure 8 which is the structural schematic diagram of an embodiment of the support arc surface of the present application, that is, the support arc surface 110 is an overall semi-circular arc shape with a uniform and identical radius. This structure can enable the test device to measure only a fixed single ultimate bending radius. In some other embodiments, the support arc surface 110 can also include multiple arc segments with diameters decreasing in sequence along the bending direction. Please refer to Figure 9 and Figure 10 , Figure 9It is a schematic structural diagram of an embodiment of the support arc surface of the present application. Figure 10 is Figure 9 a schematic cross-sectional structure diagram of the middle support arc surface. Wherein, when the number of bending radii R = n, and n = 1, 2, 3,... the test radii are RA, RB, RC,..., RN, where RA > RB > RC >... > RN. Figure 9 and Figure 10 shows the contour when n = 6. Adjacent bending radii are tangent. Specifically, the centers of multiple arc segments can be located on the surface of the rotation axis 201 of the rotating plate 200, that is, the rotation center of the rotation axis 201 is tangent to each radius, reducing the pulling force on the flexible material or flexible screen during rotation, and further reducing the impact of mutations when the radii of different gradients change; the reason why R decreases step by step along the test rotation direction is that by controlling the rotation angle, the bending radius of the flexible material or flexible screen is gradually explored until the tested material fails, and the radius Rf corresponding to the failure can be recorded.

[0034] Optionally, please continue to refer to Figure 3 and Figure 4 The rotating plate 200 includes a main board body 230, a first connecting arm 210, and a second connecting arm 220. The first connecting arm 210 and the second connecting arm 220 are arranged at opposite ends on the same side of the main board body 230, and the first connecting arm 210 and the second connecting arm 220 are respectively hinged to the fixing plate 100.

[0035] Please continue to refer to Figure 3 and Figure 5 Among them, the tension unit 300 includes a sliding connecting plate 310 and a tension element 320. The sliding connecting plate 310 is slidably connected to the main board body 230 of the rotating plate 200 and is used for fixedly connecting with the flexible material 88 to be tested. The tension element 320 is respectively connected to the sliding connecting plate 310 and the main board body 230, and is used to provide the tensile pre-tightening force for the flexible material 88.

[0036] Optionally, the tension element 320 in this embodiment includes a first tension element 321 and a second tension element 322. The first tension element 321 and the second tension element 322 are respectively arranged on opposite sides of the sliding connecting plate 310 in the sliding direction ( Figure 5 the double-arrow direction in

[0037] During the sliding process of the sliding connecting plate 310, the first tension element 321 and the second tension element 322 jointly exert a force on the sliding connecting plate 310. Figure 3 and Figure 11 ), Figure 11 It is a schematic structural diagram of another embodiment of the tension element of the present application. Among them,Figure 11 In the first tension element 321 and the second tension element 322 can be a structure in which a spring and a magnetic member cooperate. Figure 3 In the first tension element 321 and the second tension element 322 can both be of a spring structure.

[0038] Among them, the main board body 230 of the rotating plate 200 is provided with a through groove 231. The sliding connection plate 310 includes a support plate 311 and a support base 312. The support plate 311 and the support base 312 are fixedly connected and form a sliding pair. The support plate 311 is arranged in the through groove 231 and can slide along the through groove 231. The tension element 320 acts on the side wall of the through groove 231.

[0039] Optionally, the rotating plate 200 in this embodiment further includes a support column 240. The support column 240 extends along the sliding direction of the sliding connection plate 310. The support column 240 is used to abut against the sliding connection plate 310 at the maximum moving position to the outside.

[0040] In this embodiment, the mechanical explanation is given by taking the structure in which the first tension element 321 and the second tension element 322 are a combination of a spring and a magnetic member as an example. Among them, the first tension element 321 can be a tension spring (sheathed on the support column 240), and the second tension element 322 can be a pair of magnets (3221 and 3222 are respectively arranged on the side wall of the through groove 231 and the side of the support plate 311).

[0041] The first tension element 321 (tension spring) provides a prestress in the rotational radial direction to prevent the support plate 311 from sliding inwards. The purpose of the pair of magnets of the second tension element 322 is to prevent the spring (the first tension element 321) from excessively pulling the flexible material or the flexible screen when the support plate 311 rotates relative to the rotating plate 200 during the test, causing damage to the material under test.

[0042] The spring is initially in a tensioned state to ensure that the support plate 311 is in contact with the support column 240 and does not slide inwards. The initial tension of the spring is F1, the stretched length of the spring is x1, and F1 = k * x1.

[0043] The initial magnetic pulling force between the magnet pairs is F2. Generally, the magnet suction force is inversely proportional to the fourth power of the displacement. As the distance between the magnets decreases, F2 shows an increasing trend; and F1 > F2. The initial spring-magnet pulling force F0 = F1 - F2, so F0 = k * x1 - F2. At this time, the reverse thrust of the support column 240 on the support plate 311 is also F0. When the rotating plate 200 rotates for testing, since a part of the flexible material 88 will be wound to the position of the support arc surface 110 of the fixed plate 100, the length of the flexible material or the flexible screen remains unchanged, and the length of the rotating plate 200 remains unchanged. Therefore, the support plate 311 will slide relative to the rotating plate along the rotation radius. Assuming the sliding displacement is δx, then the spring-magnet pulling force F = F1' - F2' = k * (x1 + δx) - F2'.

[0044] When the rotating end rotates 180° (please refer to Figure 12 , Figure 12 which is the structural schematic diagram of the 180-degree bending state of the flexible material in the test process of this application), at this time, δx is the largest, and the maximum value is xmax. At this time, the magnet suction force is the largest, set as F2max. Through the design of the spring and the magnet, the mechanism needs to ensure that k * (x1 + xmax) > F2max, so as to ensure that the rotating plate 200 can keep pulling the flexible material or the flexible screen during the rotation process, that is, the contact on the support arc surface 110 of the fixed plate 100 is effective, and the flexible material or the flexible screen can be effectively bent and tested.

[0045] Please continue to refer to Figure 2 and Figure 3 , in the middle of the fixed plate 100 in this embodiment, there is an avoidance groove 101. The avoidance groove 101 is used to accommodate the devices (not shown in the figure) on the flexible material 88. When the flexible material 88 is a display screen, there may be devices such as control chips on it, and the avoidance groove 101 is used to accommodate and avoid these devices.

[0046] Next, the process of testing the bending of the flexible material by the test device in the embodiment of this application will be described. Among them, this test process can generally be roughly divided into three states.

[0047] 1) Initial state ( Figure 5 in the state shown in, the included angle between the fixed plate 100 and the rotating plate 200 is 0°)) One end of the flexible material 88 is fixed on the fixed plate 100, and the other end is fixed on the support plate 311. The middle area is the test area.

[0048] 2) Process state (0° < (the included angle between the fixed plate 100 and the rotating plate 200) < 180°) During the test process, the rotating plate 200 rotates a certain angle around the rotation axis 201, and observes whether the tested material fails. For example, Figure 6 is a test device for the bending strength of a contact-type flexible material testing area A. At this time, the bending radius of the material is RA, Figure 7When the test device for the bending strength of a contact-type flexible material tests the B area, the bending radius of the material is RB at this time. During this process, through the sliding of the support plate 311 along the radial direction of the rotation of the rotating plate 200 and the combined action of the spring force and the magnetic force, the flexible material 88 to be tested can form an effective test on the support arc surface 110 of the fixed plate 100.

[0049] 3) Merged state (the angle between the fixed plate 100 and the rotating plate 200 is 180°), Figure 12 In this state, the rotating plate 200 rotates 180° relative to the fixed plate 100. At this time, the test radius is RF. Observe whether the flexible material 88 to be tested fails. If the material to be tested still does not fail, a test device with a smaller radius is required for testing, such as tangent splicing of circular arcs with radii RA’, RB’, RC’, RD’, RE’, RF’, where RA’ < RF, until the failure position of the flexible material or flexible screen to be tested, and record the test radius RX at this time.

[0050] The test device for the bending of the flexible material in the embodiment of the present application proposes a rotary contact test method for testing the bending limit radius of the flexible material or the flexible screen, and has a test effect of stable measurement and direct result reading. This device realizes the test during the contact process between the material to be tested and the formed profile through the rotational movement of the rotating end and the design of the formed profile (support arc surface) at the end of the fixed plate. By adjusting the radius of the formed profile, the bending radius of the material to be tested is directly controlled, so as to realize the test of the limit bending radius of the folding screen or the folding material. Through the introduction of the above scheme, it can be seen that the test device in the embodiment of the present application can realize the screen bending test during the 0-180° bending process, and has the characteristics of simple and stable test, good repeatability, and direct measurement reading. Through the contact rotary test, the flexible material or the flexible screen with different bending radii can be tested stably and effectively; and during the rotation process, the length of the flexible screen is effectively compensated to avoid damage to the flexible material to be tested.

[0051] The above are only some embodiments of the present application, and thus do not limit the protection scope of the present application. Any equivalent device or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A test device for bending a flexible material, characterized in that, The test device includes: A fixed plate with a supporting arc surface at its end; A rotating plate hinged to one end of the fixed plate where the supporting arc surface is provided; A tension unit slidably connected to the rotating plate; During the test of the flexible material, one end is fixedly connected to the fixed plate, and the other end is fixedly connected to the tension unit, and it can be bent driven by the rotating plate. During the bending process, the tension unit provides the tensile pre-tightening force for the flexible material, so that the middle part of the flexible material remains in contact with the supporting arc surface of the fixed plate, thereby testing the ultimate bending radius of the flexible material.

2. The test device according to claim 1, wherein The supporting arc surface includes a plurality of arc surface segments with diameters decreasing in sequence along the bending direction.

3. The testing device according to claim 2, wherein The centers of the plurality of arc surface segments are all located on the surface of the rotation axis of the rotating plate.

4. The testing device according to claim 1, wherein The rotating plate includes a main board body, a first connecting arm and a second connecting arm. The first connecting arm and the second connecting arm are arranged at opposite ends on the same side of the main board body, and the first connecting arm and the second connecting arm are respectively hinged to the fixed plate.

5. The testing device according to claim 4, characterized in that, The tension unit includes a sliding connecting plate and a tension element. The sliding connecting plate is slidably connected to the main board body of the rotating plate and is used for fixedly connecting with the flexible material to be tested. The tension element is respectively connected to the sliding connecting plate and the main board body and is used to provide the tensile pre-tightening force for the flexible material.

6. The test device according to claim 5, characterized in that, The tension element includes a first tension element and a second tension element. The first tension element and the second tension element are respectively arranged on opposite sides of the sliding connecting plate in the sliding direction. During the sliding process of the sliding connecting plate, the first tension element and the second tension element jointly exert forces on the sliding connecting plate.

7. The test device according to claim 6, characterized in that, The rotating plate further includes a support column extending along the sliding direction of the sliding connecting plate, and the support column is used to hold the sliding connecting plate at its maximum moving position outward.

8. The test device according to claim 6, wherein, The first tension element and the second tension element are selected from any one of a spring and a magnetic mechanism.

9. The test device according to claim 5, characterized in that, A through groove is provided on the main board body of the rotating plate. The sliding connecting plate includes a support plate and a support base. The support plate and the support base are fixedly connected. The support plate is arranged in the through groove and can slide along the through groove, and the tension element acts on the side wall of the through groove.

10. The test device according to any one of claims 1-9, characterized in that, An avoidance groove is provided in the middle of the fixed plate, and the avoidance groove is used to accommodate the devices on the flexible material.

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