WO2023185884A1

WO2023185884A1 - Foldable-screen auxiliary apparatus and manufacturing method therefor, and related device

Info

Publication number: WO2023185884A1
Application number: PCT/CN2023/084521
Authority: WO
Inventors: 司晖; 王林泉; 李小龙; 龙浩晖; 方建平
Original assignee: 华为技术有限公司
Priority date: 2022-03-30
Filing date: 2023-03-28
Publication date: 2023-10-05
Also published as: CN116935742A

Abstract

A foldable-screen auxiliary apparatus and a manufacturing method therefor, and a related device. The apparatus comprises a balance transmission line. The balance transmission line comprises a first conductive layer (101), a dielectric layer (103) and a second conductive layer (102), which are sequentially stacked, wherein a first end of the first conductive layer (101) is connected to a time domain reflectometry (TDR) module (104), and a first end of the second conductive layer (102) is grounded; the first conductive layer (101) is used for receiving a first pulse signal emitted by the TDR module (104); when a foldable screen is bent, the thickness of a bent area of the dielectric layer (103) is reduced from a first thickness to a second thickness; the first conductive layer (101) is further used for forming a corresponding first reflection signal on the basis of the first pulse signal, and transmitting the first reflection signal to the TDR module (104); and the TDR module (104) is used for determining a bending angle of the foldable screen on the basis of the first pulse signal and the first reflection signal.

Description

A folding screen auxiliary device and its production method and related equipment

This application requires the priority of the Chinese patent application submitted to the China Patent Office on March 30, 2022, with the application number 202210327278.4 and the application title "A folding screen auxiliary device and its production method and related equipment", and its entire content has been approved This reference is incorporated into this application.

Technical field

The present application relates to the field of folding screens, and in particular to a folding screen auxiliary device and its production method and related equipment.

Background technique

After the official debut of folding screen mobile phones, the practical capabilities of folding screens have attracted more and more attention from users. Among them, the hover function, as one of the important functions and selling points of folding phones, has also become a hot spot for the research and development of folding screen mobile phones. Currently, the mainstream solution for implementing the hover function is to use an external Hall sensor, which outputs different voltages based on changes in the external magnetic field to identify different bending angles, thereby realizing different functions in the hovering state of the mobile phone; or using flexible pressure The sensor outputs different pressure signals based on different folding angles to identify the bending angle, etc.

However, the above solutions all use external sensors, which will not only increase the manufacturing cost, but also increase the thickness and weight of the entire machine, seriously affecting the user experience.

Contents of the invention

Embodiments of the present application provide a folding screen auxiliary device, its manufacturing method and related equipment, which can realize low-cost, lightweight and high-precision bending angle identification of a folding machine.

The folding screen auxiliary device provided by the embodiment of the present application can be applied to electronic devices including folding screens. The electronic device may be a smartphone, a tablet computer, a head-mounted virtual reality (VR) device, a smart home appliance, some medical equipment, etc., which are not specifically limited in the embodiments of this application.

In a first aspect, embodiments of the present application provide a folding screen auxiliary device, which is applied to folding screens; the device includes a balanced transmission line, and the balanced transmission line includes a first conductive layer, a dielectric layer and a second conductive layer stacked in sequence; The first end of the first conductive layer is connected to the time domain reflection technology TDR module, and the first end of the second conductive layer is grounded; the first conductive layer is used to receive the first pulse emitted by the TDR module. Signal; when the folding screen is bent, the thickness of the bending area of the dielectric layer is reduced from the first thickness to the second thickness, and the first conductive layer is also used to form a corresponding corresponding signal based on the first pulse signal. a first reflection signal, and transmit the first reflection signal to the TDR module; the TDR module is used to determine the bending angle of the folding screen based on the first pulse signal and the first reflection signal .

In the embodiment of the present application, a balanced transmission line can be laid in the folding screen, and the balanced transmission line can include two upper and lower metal lines (such as a first conductive layer and a second conductive layer) and a middle dielectric layer. Based on time domain reflectometry (TDR), a pulse signal (i.e., incident wave, such as the above-mentioned first pulse signal) is emitted to the balanced transmission line. If the folding screen is in a completely flat state (i.e., unbent state), The impedance (or characteristic impedance) of each point along the balanced transmission line is the same and will not form a reflected signal. However, when the folding screen is bent, the dielectric layer in the bent area will be squeezed and its thickness will be reduced ( That is, the distance between the two metal lines decreases), so that the impedance value of the balanced transmission line in the bending area will change (generally become smaller), so a corresponding reflected signal (ie, reflected wave, such as the above-mentioned first reflected signal) will be formed. ), based on which the bending angle of the current folding screen can be quickly and accurately detected. In this way, compared with the traditional method of adding external As for the solution of using sensors (such as Hall sensors or flexible pressure sensors) to identify the bending angle of the folding screen, thereby increasing the thickness, weight and manufacturing cost of the entire machine, the embodiments of the present application can be directly used in the process of preparing the folding screen. By laying a balanced transmission line within the stack, we can quickly and accurately detect the bending angle of the folding screen based on the time domain reflection technology and the impedance change characteristics of the balanced transmission line. It has strong anti-interference ability and high detection sensitivity without increasing the overall cost. The thickness and weight of the machine are low, the cost is simple, and the process is simple to meet the actual needs of users.

In a possible implementation, when the folding screen cracks, the first conductive layer and/or the second conductive layer breaks, and the first conductive layer is also used based on the third conductive layer. A pulse signal forms a corresponding second reflection signal, and the second reflection signal is transmitted to the TDR module; the TDR module is also used to determine the corresponding second reflection signal based on the first pulse signal and the second reflection signal. Describe the crack size and crack location of the folding screen.

In the embodiment of the present application, when cracks (usually micro-cracks) occur in the stack at the edge of the folding screen, the balanced transmission lines in the screen will also be affected, such as the upper and lower metal lines in the balanced transmission lines (such as the first conductive layer and The second conductive layer) will break at the crack position (for example, it can be understood as an open circuit), so that the impedance value of the balanced transmission line at the break position will increase significantly. Based on this and in the same way, if a pulse signal (such as a second pulse signal) is input through the TDR module at this time, a corresponding reflection signal (such as a second reflection signal) will be formed at the fracture position, thereby identifying whether the folding screen exists cracks, and further identify the size and location of the cracks, etc., so as to improve the quality inspection of the folding screen before leaving the factory and ensure the user experience.

In a possible implementation, the TDR module includes a transmitting circuit and a receiving circuit, and the transmitting circuit and the receiving circuit are respectively connected to the first end of the first conductive layer; the transmitting circuit, for transmitting the first pulse signal to the first conductive layer; the receiving circuit for receiving the first reflected signal transmitted by the first conductive layer; and, based on the first pulse signal and The amplitude difference between the first reflected signals determines the bending angle of the folding screen.

In the embodiment of the present application, the TDR module may include a transmitting circuit and a receiving circuit, wherein the transmitting circuit and the receiving circuit may share a port (or called an interface) and be connected to a metal line in a balanced transmission line (for example, an upper metal line, that is, The starting end (for example, the first port) of the first conductive layer) is connected. In this way, as mentioned above, the first pulse signal can be transmitted to the upper metal line in the balanced transmission line through the transmitting circuit in the TDR module. When the folding screen is bent, the first pulse signal transmitted back by the upper metal line can be received through the receiving circuit in the TDR module. The first reflection signal, and based on the amplitude difference between the first pulse signal and the first reflection signal, quickly and accurately determines the bending angle of the folding screen, providing effective support for the suspension function of the folding machine. Optionally, in general, the greater the amplitude difference between the first pulse signal and the first reflection signal, the greater the degree of bending of the folding screen (that is, the smaller the bending angle).

In a possible implementation, the receiving circuit is further configured to: receive the second reflection signal transmitted by the first conductive layer; based on the relationship between the first pulse signal and the second reflection signal The amplitude difference of the first pulse signal is determined to determine the crack size of the folding screen, and the crack position of the folding screen is determined based on the time difference between transmitting the first pulse signal and receiving the second reflection signal.

In the embodiment of the present application, correspondingly, when a crack occurs on the folding screen, the second reflection signal transmitted back by the upper metal line can be received through the receiving circuit in the TDR module, and based on the combination of the first pulse signal and the second reflection signal, The amplitude difference between them can quickly and accurately determine the crack size of the folding screen. Generally speaking, the greater the amplitude difference between the first pulse signal and the second reflection signal, the more obvious the crack in the folding screen is (for example, the larger the crack area and the deeper the crack). And, the receiving circuit can also determine the crack position of the folding screen based on the time difference between transmitting the first pulse signal and receiving the second reflection signal. Generally, the larger the time difference, the farther the crack position is from the origin of the balanced transmission line. The starting end (that is, the end where the first pulse signal is input). In this way, it is possible to accurately and efficiently identify whether there are cracks in the folding screen, and further identify the size and location of the cracks, etc., so as to improve the quality inspection of the folding screen before leaving the factory and ensure the user experience.

In a possible implementation, the amplitudes of the first reflected signal and the second reflected signal are smaller than the amplitude of the first pulse signal; the phase of the first reflected signal is different from that of the first pulse signal. The phases of the signals are opposite, and the phase of the second reflected signal is the same as the phase of the first pulse signal.

In this embodiment of the present application, the amplitudes of the first reflection signal and the second reflection signal are smaller than the amplitude of the first pulse signal. Therefore, the amplitudes between the first reflection signal/the second reflection signal and the first pulse signal can be determined. The difference in values can be quickly and accurately analyzed to calculate the bending angle/crack size of the folding screen. Moreover, it can be seen from the impedance change characteristics of the balanced transmission line that when the folding screen is bent, the dielectric layer in the balanced transmission line will be compressed and thinned in the bending area, causing the impedance value of the balanced transmission line in the bending area to decrease, thus forming a third The phase of a reflected signal is opposite to the phase of the input first pulse signal (that is, the phase difference is 180°). However, when a crack occurs in a folding screen, the upper metal line and/or the lower metal line in the balanced transmission line will also have corresponding fracture traces at the crack location (for example, it can be understood as an open circuit), causing the impedance value of the balanced transmission line at the crack location to increase. , so the phase of the second reflected signal formed is the same as the phase of the input first pulse signal. In this way, based on the different phases of the reflected signals, it can be accurately identified whether the current folding screen is bent or cracked.

In a possible implementation, the first conductive layer includes a first metal layer, a second metal layer and a third metal layer stacked in sequence, and the material of the first metal layer and the third metal layer is Ti, the material of the second metal layer is Al; the second conductive layer includes a fourth metal layer, a fifth metal layer and a sixth metal layer stacked in sequence; the fourth metal layer and the sixth metal layer The material of the layer is ITO, and the material of the fifth metal layer is Ag.

In the embodiment of the present application, the upper metal line (such as the first conductive layer) in the balanced transmission line can be made of Ti Al Ti metal, and the lower metal line (such as the second conductive layer) can be made of a composite transparent conductive film ITO/Ag/ITO. , to improve the conductive properties and provide effective guarantee for the solutions of realizing the bending angle identification and crack detection of the folding screen through the balanced transmission line in the embodiment of this application.

In a possible implementation, the second end of the first conductive layer and the second end of the second conductive layer are respectively connected to two ends of a balancing resistor, and the resistance of the balancing resistor is equal to that of the balancing resistor. The impedance values of transmission lines are equal.

In the embodiment of the present application, a balancing resistor may be connected to the ends of the upper and lower metal lines in the balanced transmission line (for example, the second end of the first conductive layer and the second end of the second conductive layer). The resistance of the balancing resistor is the same as the balance The impedance values of the transmission lines are equal, so that the characteristic impedance of the balanced transmission line can be completely balanced, improving the anti-interference ability and detection sensitivity, and ensuring the user experience. It should be understood that the impedance value of the balanced transmission line described here is the original impedance value of the balanced transmission line when the folding screen is not bent and no cracks occur.

In a possible implementation, the impedance value of the balanced transmission line satisfies the following formula:

Wherein, Z is the impedance value of the balanced transmission line, Er is the dielectric constant of the dielectric layer, H is the thickness of the dielectric layer, and W is the wiring of the first conductive layer and the second conductive layer. Width, T is the wiring thickness of the first conductive layer and the second conductive layer; Ln is the natural logarithm.

In the embodiment of the present application, it can be known from the characteristic impedance formula of the balanced transmission line that when the folding screen is bent, the dielectric layer in the bending area of the balanced transmission line will be squeezed, and its thickness H will become smaller, so that the balanced transmission line will The impedance value Z in the bending area is bound to decrease. Based on this, under the incident first pulse signal, the bending area will form a corresponding first reflection signal and transmit it back to the incident end (i.e., the TDR module), thereby quickly and accurately identifying the bending angle of the folding screen.

In a possible implementation, the folding screen includes a sequentially stacked optical organic coating (ie, optical coating (OC) layer), a touch layer (Touch On Encapsulation, TOE) on the encapsulation layer, Thin film encapsulate (TFE) layer, second gate insulating layer, first gate insulating layer and polyimide (polyimide, PI) substrate; the balanced transmission line is embedded in the TFE layer, the a second gate insulating layer and the first gate insulating layer.

In the embodiment of the present application, the folding screen includes a multi-layer structure. In the embodiment of the present application, the folding screen can be prepared directly in the process of preparing the folding screen. , the balanced transmission line is conveniently laid in the stack (for example, the balanced transmission line can be embedded in the TFE layer, the second gate insulating layer and the first gate insulating layer), and the process is simple. In this way, embodiments of the present application can achieve efficient and accurate folding and bending angle identification and folding screen crack detection without increasing the thickness, weight, manufacturing cost and man-hours of the entire machine.

In the second aspect, embodiments of the present application provide a folding screen assistance method, which is applied to folding screens; the folding screen includes a balanced transmission line and a time domain reflection technology TDR module; the balanced transmission line includes a first conductive layer stacked in sequence, dielectric layer and second conductive layer; the first end of the first conductive layer is connected to the TDR module, and the first end of the second conductive layer is grounded; the method includes: receiving the The first pulse signal emitted by the TDR module; when the folding screen is bent, the thickness of the bending area of the dielectric layer is reduced from the first thickness to the second thickness, through the first conductive layer, based on the The first pulse signal forms a corresponding first reflection signal, and the first reflection signal is transmitted to the TDR module; through the TDR module, based on the first pulse signal and the first reflection signal, it is determined that the The bending angle of the foldable screen.

In a possible implementation, when the folding screen cracks, the first conductive layer and/or the second conductive layer breaks, and the method further includes: through the first conductive layer, A corresponding second reflection signal is formed based on the first pulse signal, and the second reflection signal is transmitted to the TDR module; through the TDR module, based on the first pulse signal and the second reflection signal, Determine the crack size and crack location of the folding screen.

In a possible implementation, the TDR module includes a transmitting circuit and a receiving circuit, and the transmitting circuit and the receiving circuit are respectively connected to the first end of the first conductive layer; The TDR module determines the bending angle of the folding screen based on the first pulse signal and the first reflection signal, including: transmitting the first pulse signal to the first conductive layer through the transmitting circuit ; Receive the first reflection signal transmitted by the first conductive layer through the receiving circuit; and, based on the amplitude difference between the first pulse signal and the first reflection signal, determine the folding The bending angle of the screen.

In a possible implementation, determining the bending angle of the folding screen based on the first pulse signal and the first reflection signal through the TDR module includes: receiving the first conductive The second reflection signal transmitted by the layer; determining the crack size of the folding screen based on the amplitude difference between the first pulse signal and the second reflection signal, and based on transmitting the first pulse signal and The time difference between receiving the second reflected signals determines the crack position of the folding screen.

In a third aspect, embodiments of the present application provide a method for manufacturing a folding screen auxiliary device. The method includes: etching to form a trench on a substrate; depositing a second conductive layer at the bottom of the trench; The orthographic projection of the second conductive layer on the substrate is smaller than the orthographic projection of the trench on the substrate; in a direction perpendicular to the substrate, the thickness of the second conductive layer is smaller than the trench The thickness of the trench; a dielectric layer is deposited on the remaining portion of the trench; a first conductive layer is deposited on the dielectric layer; the orthographic projection of the first conductive layer on the substrate is smaller than the dielectric layer where the Orthographic projection on the substrate.

In a possible implementation, the substrate includes a second gate insulating layer, a first gate insulating layer and a polyimide PI substrate that are stacked in sequence.

In a possible implementation, depositing a first conductive layer on the dielectric layer includes: sequentially depositing a third metal layer, a second metal layer and a first metal layer on the dielectric layer; the first The material of the metal layer and the third metal layer is Ti, and the material of the second metal layer is Al.

In a possible implementation, depositing the second conductive layer at the bottom of the trench includes: sequentially depositing a sixth metal layer, a fifth metal layer and a fourth metal layer at the bottom of the trench; The fourth metal layer and the sixth metal layer are made of ITO, and the fifth metal layer is made of Ag.

In a possible implementation, the first end of the first conductive layer is connected to the transmitting circuit and the receiving circuit in the time domain reflectometry TDR module respectively, and the first end of the second conductive layer is connected to ground; The second end of the first conductive layer and the second end of the second conductive layer are respectively connected to both ends of the balancing resistor. The resistance of the balancing resistor is consistent with the first conductive layer, the dielectric layer and the second conductive layer. The impedance values of the balanced transmission lines are equal.

In the fourth aspect, embodiments of the present application provide a folding screen auxiliary device, which is applied to folding screens. The device includes the balanced transmission line and the TDR module described in any one of the above first aspects.

In a fifth aspect, embodiments of the present application provide an electronic device, which includes a folding screen. The folding screen includes the folding screen auxiliary device described in any one of the above first aspects, for realizing the second aspect. The folding screen auxiliary method described in any one of the above.

In a sixth aspect, embodiments of the present application provide an electronic device. The electronic device includes a processor, and the processor is configured to support the electronic device to perform corresponding functions in any of the folding screen assistance methods provided in the second aspect. The electronic device may also include a memory coupled to the processor that stores necessary program instructions and data for the electronic device. The electronic device may also include a communication interface for the electronic device to communicate with other devices or communication networks.

In a seventh aspect, embodiments of the present application provide a computer-readable storage medium that stores a computer program. When the computer program is executed by a processor, it implements any one of the above-mentioned methods in the second aspect. Folding screen auxiliary method process.

In an eighth aspect, embodiments of the present application provide a computer program. The computer program includes instructions. When the computer program is executed by a computer, the computer can execute the folding screen assistance method process described in any one of the above second aspects. .

In a ninth aspect, embodiments of the present application provide a chip. The chip includes a processor and a communication interface. The processor is configured to call and run instructions from the communication interface. When the processor executes the instructions, the chip Execute the folding screen auxiliary method process described in any one of the above second aspects.

In a tenth aspect, embodiments of the present application provide a chip system. The chip system includes the folding screen auxiliary device described in any one of the above first aspects, and is used to implement any one of the folding screen auxiliary devices provided in the above second aspect. The functions involved in the method flow. In a possible design, the chip system further includes a memory, and the memory is used to store program instructions and data necessary for a floating-point number processing method. The chip system may be composed of chips, or may include chips and other discrete devices.

Description of drawings

Figure 1 is a schematic diagram of a folding screen provided by an embodiment of the present application.

Figure 2 is a schematic structural diagram of a balanced transmission line provided by an embodiment of the present application.

FIG. 3 is a schematic diagram of a set of folding screens in a bent state according to an embodiment of the present application.

FIG. 4 is a schematic diagram of impedance changes of a balanced transmission line provided by an embodiment of the present application.

Figure 5 is a schematic diagram of a folding screen bending angle identification solution provided by an embodiment of the present application.

Figure 6 is a schematic diagram of another folding screen bending angle identification solution provided by an embodiment of the present application.

FIG. 7 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

Figure 8 is a schematic structural diagram of a folding screen auxiliary device provided by an embodiment of the present application.

Figure 9 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

Figures 10a-10c are schematic diagrams of a set of folding screens in a flat state according to an embodiment of the present application.

11a-11c are schematic diagrams of a set of folding screens in a bent state according to an embodiment of the present application.

Figures 12a-12c are schematic diagrams of a set of folding screens in a cracked state according to an embodiment of the present application.

Figure 13 is a schematic flowchart of a manufacturing method of a folding screen auxiliary device provided by an embodiment of the present application.

Figures 14a-14f are schematic diagrams of the manufacturing process of a set of folding screen auxiliary devices provided by embodiments of the present application.

Figure 15 is a schematic flowchart of a folding screen assistance method provided by an embodiment of the present application.

Detailed ways

The embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

The terms “first”, “second”, etc. in the description, claims, and drawings of this application are used to distinguish different objects, rather than describing a specific sequence. Furthermore, the terms "including" and "having" 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 optionally also includes steps or units that are not listed, or optionally also includes Other steps or units inherent to such processes, methods, products or devices. It should be noted that when an element is referred to as being "coupled" or "connected" to another element or elements, it can mean that one element is directly connected to the other or multiple elements, or it can be indirectly connected to the other element or elements. One or more components.

It should be understood that in this application, "at least one (item)" refers to one or more, and "plurality" refers to two or more. "And/or" is used to describe the relationship between associated objects, indicating that there can be three relationships. For example, "A and/or B" can mean: only A exists, only B exists, and A and B exist simultaneously. , where A and B can be singular or plural. The character "/" generally indicates that the related objects are in an "or" relationship. “At least one of the following” or similar expressions thereof refers to any combination of these items, including any combination of a single item (items) or a plurality of items (items). For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c" ”, where a, b, c can be single or multiple.

Reference herein to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

The terms "component", "module", "system", etc. used in this specification are used to refer to computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to, a process, a processor, an object, an executable file, a thread of execution, a program and/or a computer running on a processor. Through the illustration, both applications running on the processor and the processor may be components. One or more components can reside in a process and/or thread of execution and a component can be localized on one computer and/or distributed between 2 or more computers. Additionally, these components can execute from various computer-readable media having various data structures stored thereon. A component may, for example, be based on having one or more data groupings Signals (eg, data from two components interacting with a local system, a distributed system, and/or another component across a network, such as the Internet that interacts with other systems via signals) are communicated through local and/or remote processes.

First, some terms used in this application are explained to facilitate understanding by those skilled in the art.

(1) Folding screen, or it can also be called "flexible screen". Please refer to Figure 1. Figure 1 is a schematic diagram of a folding screen provided by an embodiment of the present application. As shown in Figure 1, screen A can be used when the folding screen mobile phone is fully folded (for example, the bending angle is 0°), and screen B can be used when the folding screen mobile phone is unfolded (for example, the bending angle is 180°). Use the screen. The structure of the folding part of the folding screen mostly uses hinges. Moreover, most of the folding screen mobile phones currently on the market use self-developed pseudo-vertebral precision hinges to achieve free hovering at multiple angles and are adapted to hovering for movie viewing and hovering. Selfie and other functions, for example, users can hover the phone on the desktop when watching a movie, eliminating the need for a phone stand. At this time, the upper part of the phone can display the movie screen, and the lower part can be used for volume adjustment, fast forward/rewind and send barrages, etc. Among them, the recognition of different hovering states, that is, the recognition of different bending angles of the folding screen, can assist the folding screen to achieve different hovering functions. For example, when the folding screen mobile phone recognizes that the bending angle is about 90°, the folding screen mobile phone You can automatically switch the playback page of screen B to the upper half of the screen, etc., to improve the user experience.

(2) Balanced transmission line. Please refer to Figure 2. Figure 2 is a schematic structural diagram of a balanced transmission line provided by an embodiment of the present application. As shown in Figure 2, a balanced transmission line is mainly composed of two parallel lines (for example, the upper metal line and the lower metal line in Figure 2. Generally, the upper metal line can be a signal line, and the lower metal line can be a ground line, or On the contrary, the embodiment of the present application does not specifically limit this), the two parallel lines may be coupled through a dielectric layer (such as a planarization layer (PLN)). This is also called a differential pair or differential line, and is also called a coupled transmission line. In some embodiments of the present application, balanced transmission lines can be embedded in the manufacturing process of the display panel (panel). For example, please refer to FIG. 3 , which is a schematic diagram of a set of folding screens in a bending state according to an embodiment of the present application. As shown in Figure 3, when the folding screen is bent, the organic dielectric layer (such as the PLN soft layer) in the balanced transmission line in the screen is squeezed in the bending area, and its thickness is reduced (that is, between the upper and lower metal lines). (the spacing is reduced), thereby causing the impedance value of the balanced transmission line in the bend area to change. For example, as shown in (a) and (b) in Figure 3, when the bending angle is different, the degree of squeezing of the dielectric layer is also different, that is, the thickness of the dielectric layer is reduced to a different extent, and the resulting impedance change will also be Different (for example, as shown in (a) and (b) in Figure 3, with different bending angles, the impedance values of the bending area can be Z1 and Z2 respectively). In this way, embodiments of the present application can quickly, conveniently and accurately identify the bending angle of the folding screen based on the impedance change, while controlling manufacturing costs and man-hours. Further, please refer to FIG. 4 , which is a schematic diagram of impedance changes of a balanced transmission line provided by an embodiment of the present application. As shown in Figure 4, when the thickness of a certain area of the dielectric layer is reduced (that is, the spacing between the upper and lower metal lines is reduced), the impedance value of the balanced transmission line in this area is significantly reduced (for example, as shown in Figure 4, it is reduced from 50Ω to 30Ω), so that the bending angle of the foldable screen can be identified. Moreover, when a crack occurs in the folding screen, the upper metal wire and/or the lower metal wire in the balanced transmission line in the screen will also break at the corresponding location of the crack. As shown in Figure 4, in the fracture area of the upper metal line (equivalent to the open circuit area), the impedance value of the balanced transmission line will increase significantly, and then it can be identified whether there is a crack in the folding screen, and further identify the size and location of the crack, thereby Complete quality inspection before leaving the factory to ensure user experience.

(3) Time domain reflectometry (TDR) is an application of radar detection technology. In the early days, it was mainly used in the communication industry to detect the breakpoint position of communication cables, so it was also called a "cable detector". A time domain reflectometry is an electronic instrument that uses time domain reflectometry to characterize and locate faults in metallic cables (e.g., twisted pair or coaxial cable). It can also be used to locate discontinuities in connectors, printed circuit boards, or any other electrical paths. Based on the time domain reflection technology and the above-mentioned impedance change principle of the balanced transmission line, in some embodiments of the present application, a transient excitation signal (i.e., pulse signal) can be input at one end of the upper metal line, and the signal can be stable in a uniform medium. Propagates forward at a constant speed until the end of the upper metal wire, and no reflected signal (ie, reflected wave) is generated during this period. However, as mentioned above, when the level When the impedance value of the bending area or crack area of the transmission line changes, the upper metal line will form a corresponding reflection signal in the bending area or crack area and transmit it back. Subsequently, the current fold can be identified based on the phase and amplitude of the reflection signal. The bending angle or crack situation of the screen, etc., please refer to the description in subsequent embodiments for details, and will not be described in detail here.

(4) Integrated circuit (IC) chip is a chip made by placing an integrated circuit formed by a large number of microelectronic components (such as transistors, resistors, capacitors, etc.) on a plastic base. Almost all the chips you see today can be called IC chips. In some embodiments of the present application, TDR-related circuits can be integrated on an IC chip (such as a display driver integrated circuit (DDIC)) and connected to a balanced transmission line for transmitting pulse signals to it and receiving corresponding The reflected signal is received, and the bending angle or crack situation is analyzed and calculated based on the received reflected signal. Optionally, the signal transmitting and receiving ports on the IC chip can be the same, and are connected to one end of the upper metal line in the balanced transmission line.

(5) Plasma enhanced chemical vapor deposition (PECVD). With the help of microwave or radio frequency, the gas containing the atoms that make up the film is locally formed into a plasma. The plasma is very chemically active and can easily react, thereby depositing the desired film on the substrate. In the PECVD process, because the high-speed moving electrons in the plasma collide with the neutral reaction gas molecules, the neutral reaction gas molecules will become fragments or be in an activated state and are prone to reactions. A good SiOx or SiNx film can be obtained by keeping the substrate temperature around 350°C.

(6) Sputter coating technology (sputter) applies high voltage to both ends of the vacuum environment electrode to generate a DC glow discharge, which ionizes the introduced process gas. Positive ions bombard the target at high speed under the action of the electric field, and the escaping target atoms and molecules are deposited onto the surface of the coated substrate.

First, in order to facilitate understanding of the embodiments of the present application, the technical problems specifically to be solved by the present application are further analyzed and proposed. The embodiments of this application exemplify the following several common solutions for identifying the bending angle of a folding machine.

Please refer to Figure 5. Figure 5 is a schematic diagram of a folding screen bending angle identification solution provided by an embodiment of the present application. As shown in Figure 5, most common folding angle recognition solutions use Hall sensors or flexible pressure sensors. Taking the flexible pressure sensor as an example, the flexible pressure sensor 22 is connected to the main and secondary screens 21 of the folding machine respectively. When folding occurs, the flexible pressure sensor 22 is connected to the main and secondary screens 21 of the folding machine. The pressure signal of the pressure sensor 22 will change, and the folding angle θ can be determined based on the change value of the pressure signal. However, the flexible pressure sensor or Hall sensor is an external sensor, which easily increases the thickness of the entire device (generally the overall thickness of a flexible pressure sensor is about 200um-300um), which also increases the manufacturing cost, and the process is complex, resulting in long manufacturing hours. .

Please refer to FIG. 6 , which is a schematic diagram of another folding screen bending angle recognition solution provided by an embodiment of the present application. As shown in Figure 6, an antenna can also be attached to the bending area of the folding screen. When folding occurs, the antenna follows the bending, and its antenna voltage standing wave ratio changes. By reading the numerical change of the standing wave ratio, Identify the bending angle of the foldable screen. However, this solution is still an external plug-in type and requires an external film antenna, which increases the thickness of the entire device. Generally, in order to ensure that the radio frequency parameters of a film antenna meet the requirements, the overall thickness of the conductive layer and protective layer is greater than 200um, and the width is greater than 500um. above. Moreover, the radio frequency antenna has an open antenna structure, which is susceptible to interference and the readings cannot be very accurate. Similarly, additional antennas will increase the cost, and the process is complicated, resulting in long manufacturing hours.

In addition, common solutions include arranging serpentine traces at the edge of the screen in the bending area, and using flexible stretching of the substrate to change the characteristics of the serpentine traces to identify the bend angle. Obviously, the detection wiring needs to be a serpentine wiring to improve the sensitivity, so it occupies a large area, and the panel has poor basic ductility. Its nature determines that its sensing sensitivity is not high, and it is susceptible to interference and affects the sensing accuracy.

Alternatively, capacitive plates can be arranged on the edge of the folding screen, and the deformation of the air layer in the patterned barrier structure can be used to drive changes in capacitance, thereby identifying the bending angle. It should be noted that this solution uses a capacitor structure, and the capacitor The plate needs a certain area to produce enough capacitance change for detection. Otherwise, the capacitance change is small and the identification is inaccurate. Therefore, the metal layer area of this solution is large and it is difficult to achieve the effect of an extremely narrow frame. The actual substrate metal layer width is generally larger than 1000um. At the same time, the open capacitor structure is easily affected by electromagnetic interference and affects detection accuracy.

Therefore, in order to solve the problem that the current folding screen bending angle identification technology does not meet actual needs, the technical problems actually to be solved by this application include the following aspects: embedding a balanced transmission line inside the folding screen, based on the fact that when the folding screen is bent, the balanced transmission line Impedance value changes in the bending area and time domain reflection technology are used to detect the bending angle of the folding screen, thereby achieving lightweight, low-cost, efficient and accurate folding screen bending angle identification to ensure user experience.

Please refer to FIG. 7 , which is a schematic structural diagram of an electronic device provided by an embodiment of the present application. The technical solutions of the embodiments of the present application may be implemented in the structure shown as an example in Figure 7 or a similar structure. The following is a detailed description of the embodiment of the present application, taking the electronic device 100 shown in FIG. 7 as an example. It should be understood that the structure illustrated in the embodiment of the present application does not constitute a specific limitation on the electronic device 100 . In some possible embodiments, the electronic device 100 may have more or fewer components than shown in the figures, or some components may be combined, or some components may be separated, or may be arranged differently. The various components shown in the figures may be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and/or application specific integrated circuits.

The electronic device 100 may include: a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, and a mobile communication module 150 , antenna system 151, wireless communication module 160, audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone interface 170D, sensor module 180, button 190, motor 191, indicator 192, camera 193, display screen 194, and user Identification module (subscriber identification module, SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyro sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, and ambient light. Sensor 180L, bone conduction sensor 180M, etc.

The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (application processor, AP), a modem processor, a graphics processing unit (GPU), and an image signal processor. (image signal processor, ISP), controller, memory, video codec, digital signal processor (digital signal processor, DSP), baseband processor, and/or neural-network processing unit (NPU) wait. Among them, different processing units can be independent devices or integrated in one or more processors.

The controller may be the nerve center and command center of the electronic device 100 . The controller can generate operation control signals based on the instruction operation code and timing signals to complete the control of fetching and executing instructions.

The processor 110 may also be provided with a memory for storing instructions and data. In some embodiments, the memory in processor 110 is cache memory. This memory may hold instructions or data that have been recently used or recycled by processor 110 . If the processor 110 needs to use the instruction or data again, it can be directly called from the memory, which avoids repeated access, reduces the waiting time of the processor 110, and thus improves the efficiency of the system.

In some embodiments, processor 110 may include one or more interfaces. Interfaces may include integrated circuit (inter-integrated circuit, I2C) interface, integrated circuit built-in audio (inter-integrated circuit sound, I2S) interface, pulse code modulation (PCM) interface, universal asynchronous receiver and transmitter (universal asynchronous receiver/transmitter (UART) interface, mobile industry processor interface (MIPI), general-purpose input/output (GPIO) interface, user identification module (subscriber) identity module, SIM) interface, and/or universal serial bus (universal serial bus, USB) interface, etc.

It can be understood that the interface connection relationships between the modules illustrated in the embodiment of the present invention are only schematic illustrations and do not constitute a structural limitation of the electronic device 100 . In other embodiments of the present application, the electronic device 100 may also adopt different interface connection methods in the above embodiments, or a combination of multiple interface connection methods.

The charging management module 140 is used to receive charging input from the charger. Among them, the charger can be a wireless charger or a wired charger.

The power management module 141 is used to connect the battery 142, the charging management module 140 and the processor 110. The power management module 141 receives input from the battery 142 and/or the charging management module 140, and supplies power to the processor 110, internal memory 121, external memory, display screen 194, camera 193, wireless communication module 160, etc.

The wireless communication function of the electronic device 100 can be implemented through the antenna system 151, the mobile communication module 150, the wireless communication module 160, the modem processor and the baseband processor, etc.

The electronic device 100 implements display functions through a GPU, a display screen 194, an application processor, and the like. The GPU is an image processing microprocessor and is connected to the display screen 194 and the application processor. GPUs are used to perform mathematical and geometric calculations for graphics rendering. Processor 110 may include one or more GPUs that execute program instructions to generate or alter display information.

The display screen 194 is used to display images, videos, etc. Display 194 includes a display panel. The display panel can use a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active matrix organic light emitting diode or an active matrix organic light emitting diode (active-matrix organic light emitting diode). emitting diode (AMOLED), flexible light-emitting diode (FLED), Miniled, MicroLed, Micro-oLed, quantum dot light emitting diode (QLED), etc. In some embodiments of the present application, the display screen 194 may be a folding screen, and a balanced transmission line may be embedded in the display screen 194. The balanced transmission line may be connected to a display driver chip (display driver integrated circuit, DDIC) in the electronic device 100. , used to receive the pulse signal emitted by the DDIC, and used to form a reflected signal corresponding to the pulse signal when the folding screen is bent or cracked, and transmit the reflected signal to the DDIC. DDIC can receive the reflected signal and identify the bending angle or cracks of the folding screen based on this, etc., which will not be described in detail here. Optionally, the electronic device 100 may include 1 or N display screens 194, such as a main screen and a secondary screen in a folding screen, where N is a positive integer greater than 1.

The electronic device 100 can implement the shooting function through an ISP, a camera 193, a video codec, a GPU, a display screen 194, an application processor, and the like. In some embodiments, electronic device 100 may include one or more cameras 193 .

The ISP is used to process the data fed back by the camera 193. For example, when taking a photo, the shutter is opened, the light is transmitted to the camera sensor through the lens, the optical signal is converted into an electrical signal, and the camera sensor passes the electrical signal to the ISP for processing, and converts it into an image visible to the naked eye. ISP can also perform algorithm optimization on image noise, brightness, and contrast. ISP can also optimize the exposure, color temperature and other parameters of the shooting scene. In some embodiments, the ISP may be provided in the camera 193.

Camera 193 is used to capture still images or video. The object passes through the lens to produce an optical image that is projected onto the photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, and then passes the electrical signal to the ISP to convert it into a digital image signal. ISP outputs digital image signals to DSP for processing. DSP converts digital image signals into standard RGB, YUV and other format image signals. The camera 193 may be located on the front of the electronic device, such as above the touch screen, or may be located at other locations, such as the back of the electronic device.

Digital signal processors are used to process digital signals. In addition to digital image signals, they can also process other digital signals. For example, when the electronic device 100 selects a frequency point, the digital signal processor is used to perform Fourier transform on the frequency point energy.

Video codecs are used to compress or decompress digital video. The electronic device 100 may support one or more video encoding decoder. In this way, the electronic device 100 can play or record videos in multiple encoding formats, such as moving picture experts group (moving picture experts group, MPEG) 1, MPEG2, MPEG3, MPEG4, etc.

NPU is a neural network (NN) computing processor. By drawing on the structure of biological neural networks, such as the transmission mode between neurons in the human brain, it can quickly process input information and can continuously learn by itself. Intelligent cognitive applications of the electronic device 100 can be implemented through the NPU, such as image recognition, face recognition, speech recognition, text understanding, etc.

The external memory interface 120 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the electronic device 100. The external memory card communicates with the processor 110 through the external memory interface 120 to implement the data storage function. Such as saving music, videos, etc. files in external memory card.

Internal memory 121 may be used to store computer executable program code, which includes instructions. The processor 110 executes instructions stored in the internal memory 121 to execute various functional applications and data processing of the electronic device 100 . The internal memory 121 may include a program storage area and a data storage area. Among them, the stored program area can store the operating system, at least one application required for the function (such as communication function, face recognition function, folding screen bending angle recognition function, video recording function, video playback function, camera function, etc.). The storage data area may store data created during use of the electronic device 100 and the like. In addition, the internal memory 121 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc.

The electronic device 100 can implement audio functions through the audio module 170, the speaker 170A, the receiver 170B, the microphone 170C, the headphone interface 170D, and the application processor. Such as music playback, recording, etc.

The audio module 170 is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signals.

Speaker 170A, also called "speaker", is used to convert audio electrical signals into sound signals.

Receiver 170B, also called "earpiece", is used to convert audio electrical signals into sound signals.

Microphone 170C, also called "microphone" or "microphone", is used to convert sound signals into electrical signals.

The headphone interface 170D is used to connect wired headphones. The headphone interface 170D may be a USB interface 130, or may be a 3.5mm open mobile terminal platform (OMTP) standard interface, or a Cellular Telecommunications Industry Association of the USA (CTIA) standard interface.

The pressure sensor 180A is used to sense pressure signals and can convert the pressure signals into electrical signals. In some embodiments, pressure sensor 180A may be disposed on display screen 194 . There are many types of pressure sensors 180A, such as resistive pressure sensors, inductive pressure sensors, capacitive pressure sensors, etc.

The gyro sensor 180B may be used to determine the motion posture of the electronic device 100 . In some embodiments, the angular velocity of electronic device 100 about three axes (ie, x, y, and z axes) may be determined by gyro sensor 180B.

Proximity light sensor 180G may include, for example, a light emitting diode (LED) and a light detector, such as a photodiode. The light emitting diode may be an infrared light emitting diode.

The ambient light sensor 180L is used to sense ambient light brightness. The electronic device 100 can adaptively adjust the brightness of the display screen 194 according to the perceived ambient light brightness. The ambient light sensor 180L can also be used to automatically adjust the white balance when taking pictures.

Fingerprint sensor 180H is used to collect fingerprints. The electronic device 100 can use the collected fingerprint characteristics to achieve fingerprint unlocking, access to application locks, fingerprint photography, fingerprint answering of incoming calls, etc. The fingerprint sensor 180H can be disposed below the touch screen. The electronic device 100 can receive the user's touch operation on the area corresponding to the fingerprint sensor on the touch screen. The electronic device 100 can respond to the touch operation and collect the fingerprint of the user's finger. information to implement related functions.

Temperature sensor 180J is used to detect temperature. In some embodiments, the electronic device 100 utilizes the temperature detected by the temperature sensor 180J to execute the temperature processing strategy.

Touch sensor 180K, also called "touch panel". The touch sensor 180K can be disposed on the display screen 194. The touch sensor 180K and the display screen 194 form a touch screen, which is also called a "touch screen". The touch sensor 180K is used to detect a touch operation on or near the touch sensor 180K. The touch sensor can pass the detected touch operation to the application processor to determine the touch event type. Visual output related to the touch operation may be provided through display screen 194 . In other embodiments, the touch sensor 180K may also be disposed on the surface of the electronic device 100 at a location different from that of the display screen 194 .

The buttons 190 include a power button, a volume button, etc. Key 190 may be a mechanical key. It can also be a touch button. The electronic device 100 may receive key inputs and generate key signal inputs related to user settings and function control of the electronic device 100 .

The indicator 192 may be an indicator light, which may be used to indicate charging status, power changes, or may be used to indicate messages, missed calls, notifications, etc.

The SIM card interface 195 is used to connect a SIM card. The SIM card can be connected to or separated from the electronic device 100 by inserting it into the SIM card interface 195 or pulling it out from the SIM card interface 195 . In some embodiments, the electronic device 100 uses an eSIM, that is, an embedded SIM card. The eSIM card can be embedded in the electronic device 100 and cannot be separated from the electronic device 100 .

The electronic device 100 may be a smartphone, a smart wearable device, a tablet computer, a smart home, etc. with the above functions, which are not specifically limited in the embodiments of the present application.

Please refer to FIG. 8 , which is a schematic structural diagram of a folding screen auxiliary device provided by an embodiment of the present application. This folding screen auxiliary device can be applied to the folding screen in the electronic device 100 shown in Figure 7. As shown in Figure 8, the device includes a balanced transmission line, which includes a first conductive layer 101 and a dielectric layer 103 stacked in sequence. and second conductive layer 102. Optionally, the first end of the first conductive layer 101 can be connected to the TDR module 104, and the first end of the second conductive layer 102 can be grounded. The first conductive layer 101 and the second conductive layer 102 are the upper metal line (signal line) and the lower metal line (ground line) in the balanced transmission line shown in FIG. 2 or FIG. 3 .

First, based on the structure of the above balanced transmission line, the impedance value of the balanced transmission line satisfies the following formula (1):

Z is the impedance value of the balanced transmission line, Er is the dielectric constant of the dielectric layer 103, H is the thickness of the dielectric layer 103 (ie, the distance between the first conductive layer 101 and the second conductive layer 102), and W is the first conductive layer. 101 and the trace width of the second conductive layer 102, T is the trace thickness of the first conductive layer 101 and the second conductive layer 102; Ln is the natural logarithm.

Specifically, the TDR module 104 may include a transmitting circuit 1041 and a receiving circuit 1042 (not shown in FIG. 8 ). The ports of the transmitting circuit 1041 and the receiving circuit 1042 may be the same, and the ports of the transmitting circuit 1041 and the receiving circuit 1042 may be the same as those of the first conductive layer 101 . One end (e.g. the starting end) is connected.

The transmitting circuit 1041 is used to transmit the first pulse signal to the first conductive layer 101 . Optionally, the first pulse signal may only include a waveform of one cycle.

The first conductive layer 101 is used to receive the first pulse signal transmitted by the transmitting circuit 1041.

Optionally, when the folding screen is bent (for example, the bending state 1 shown in FIG. 3 above), the dielectric layer 103 in the bending area will be squeezed, causing the thickness of the dielectric layer 103 in the bending area to change from The first thickness is reduced to the second thickness (that is, the distance between the first conductive layer 101 and the second conductive layer 102 is reduced). It can be seen from the above formula (1) that when the thickness of the dielectric layer 103 in the bending area decreases, the impedance value Z of the balanced transmission line in the bending area will decrease accordingly. Therefore, when the folding screen is bent, the first conductive layer 101 is also used to form a corresponding first reflection signal in the bending area based on the first pulse signal, and to transmit the first reflection signal to the receiving circuit 1042.

Correspondingly, when the folding screen is bent, the receiving circuit 1042 is used to receive the first reflection transmitted by the first conductive layer 101 signal; and, based on the amplitude difference between the first pulse signal and the first reflection signal, determine the bending angle of the folding screen. Generally, the amplitude of the first reflection signal is smaller than the amplitude of the first pulse signal. The greater the amplitude difference between the first pulse signal and the first reflection signal, the greater the degree of bending of the folding screen (i.e., the degree of bending). The smaller the folding angle is).

Optionally, when a crack occurs in the folding screen, the first conductive layer 101 and/or the second conductive layer 102 in the balanced transmission line in the screen will also be affected, and a break will occur in the crack area, that is, an open circuit. Obviously, when the break occurs The impedance value Z of the position-balanced transmission line will increase significantly. Therefore, when a crack occurs in the folding screen, the first conductive layer 101 is also used to form a corresponding second reflection signal at the crack position based on the first pulse signal, and transmit the second reflection signal to the receiving circuit 1042.

Correspondingly, when the folding screen cracks, the receiving circuit 1042 is used to receive the second reflection signal transmitted by the first conductive layer 101; based on the amplitude difference between the first pulse signal and the second reflection signal, determine the folding screen The size of the crack, and the crack position of the folding screen is determined based on the time difference between transmitting the first pulse signal and receiving the second reflection signal. Generally, the amplitude of the second reflection signal is smaller than the amplitude of the first pulse signal. The greater the amplitude difference between the first pulse signal and the second reflection signal, the more obvious the crack in the folding screen is (for example, the larger the crack area is) The larger, the deeper the fracture). In addition, generally speaking, the larger the time difference is, the farther the crack position is from the first end of the first conductive layer 101 (ie, the input end of the first pulse signal).

It should be noted that from the above-mentioned bending state and the different impedance value change characteristics caused by the occurrence of cracks, it can be seen that the phase of the first reflected signal is opposite to the phase of the first pulse signal (that is, the phase difference is 180°), and the phase of the second reflected signal is 180°. The phase is the same as the phase of the first pulse signal. In this way, based on the phase difference of the reflected signal, the receiving circuit 1042 can quickly and accurately identify whether the current folding screen is bent or cracked, so as to further identify the bending angle or analyze the crack size and crack location, etc.

Optionally, the second end (for example, an end) of the first conductive layer 101 and the second end of the second conductive layer 102 can be connected to two ends of a balancing resistor respectively. The resistance of the balancing resistor is generally the same as that of the balanced transmission line. The impedance values are equal, so that the characteristic impedance of the balanced transmission line can be completely balanced. On the basis that the balanced transmission line is not susceptible to external electromagnetic interference, the anti-interference ability and detection sensitivity are further improved, ensuring the folding screen bending angle identification in this application. and the accuracy of crack detection, thereby ensuring the user’s experience.

Please refer to FIG. 9 , which is a schematic structural diagram of an electronic device provided by an embodiment of the present application. The electronic device 100 may be, for example, the electronic device 100 shown in FIG. 7 , including a folding screen. As shown in FIG. 9 , balanced transmission lines, specifically including balanced transmission line 1 and balanced transmission line 2 , can be embedded in the upper and lower edges of the folding screen of the electronic device 100 . Among them, the starting ends of the balanced transmission line 1 and the balanced transmission line 2 (for example, the first end of the first conductive layer 101 mentioned above) can be respectively connected to the TDR signal transmitting/receiving port 1 and the TDR signal transmitting/receiving port 2 in the DDIC to respectively Receive the pulse signal transmitted by DDIC and transmit the corresponding reflected signal to DDIC. Correspondingly, the DDIC can be integrated with the TDR module 104 shown in Figure 8, which can include two transmitting circuits and a receiving circuit for transmitting the first pulse signal to the balanced transmission line 1 and the balanced transmission line 2 respectively, and receiving the balanced transmission line 1 and 2 respectively. The transmission line 1 and the balanced transmission line 2 transmit back the corresponding first reflected signal or the second reflected signal. Therefore, the DDIC can combine the first reflection signal or the second reflection signal corresponding to the balanced transmission line 1 and the balanced transmission line 2 to more accurately calculate the bending angle of the folding screen in the electronic device 100 or the crack situation of the folding screen (for example, taking The average of the two calculation results, etc.).

Optionally, in order to further reduce the production cost, the electronic device 100 can also be provided with only balanced transmission line 1 or balanced transmission line 2. Correspondingly, the DDIC can also be provided with only one transmitting circuit and one receiving circuit, etc., in the embodiment of the present application There is no specific limit on this.

Further, as shown in FIG. 9 , the DDIC also includes a chip on flex (or, chip on film, COF). Among them, COF is mainly a die soft film construction technology that fixes integrated circuits (such as DDIC) on flexible circuit boards. No further details will be given here.

In addition, it should be noted that the COF, DDIC, etc. shown in Figure 9 are actually arranged under the folding screen. In order to clearly introduce and illustrate their structure, the embodiment of the present application shows that the COF, DDIC, etc. are exemplified from under the screen. "Flip" it out.

Below, a folding screen auxiliary device and related methods provided by this application will be described in detail through the folding screen in different states.

Please refer to Figures 10a-10c. Figures 10a-10c are schematic diagrams of a set of folding screens in a flat state according to an embodiment of the present application.

As shown in Figure 10a, when the folding screen is in a flat state (not bent), the dielectric layer in the balanced transmission line (taking the PLN soft layer as an example in Figure 10a) is not squeezed, and the characteristic impedance of each point along the balanced transmission line is The values are uniformly distributed and constant. Please also refer to Figure 10b. Figure 10b is the equivalent circuit of the balanced transmission line when the folding screen is in the flat state. As shown in Figure 10b, the resistance R, inductance L, conductance G and capacitance C at each point on the balanced transmission line are all equal. The impedance value formed by it is equal to the resistance of the trim resistor connected at the end, which is 50Ω.

Please refer to Figure 10c. When the folding screen is in the flat state, a transient excitation signal (such as the above-mentioned first pulse signal) is input at the starting end, that is, the incident wave in Figure 10c. This incident wave will propagate at a uniform speed in the uniform medium until At the end, no reflected waves will be generated. It should be noted that the incident wave in Figure 10c only includes a waveform of one period. Only this incident wave propagates forward in the balanced transmission line. The dotted line represents the scene of the same incident wave propagating forward at different times. The following The same applies to the above embodiments and will not be explained again.

Please refer to Figures 11a-11c. Figures 11a-11c are schematic diagrams of a set of folding screens in a bent state according to embodiments of the present application.

As shown in Figure 11a, when the folding screen is bent, the dielectric layer in the balanced transmission line (taking the PLN soft layer as an example in Figure 11a) is squeezed, and its thickness in the bent area is reduced. Please also refer to Figure 11b. Figure 11b is the equivalent circuit of the balanced transmission line when the folding screen is bent. As shown in Figure 11b, the conductance and capacitance of the balanced transmission line change in the bending area, which are G' and C' respectively. The impedance value Z of the balanced transmission line in the bend area decreases accordingly.

Please refer to Figure 11c. When the folding screen is in a bent state, a transient excitation signal (such as the above-mentioned first pulse signal) is input at the starting end, that is, the incident wave in Figure 11c. When the incident wave propagates to the bending area (i.e. When the impedance value changes), a corresponding reflected wave (such as the above-mentioned first reflected signal) will be formed, and the reflected wave has a negative polarity (that is, the phase is opposite to that of the incident wave). The amplitude of the reflected wave may be X, and the more the impedance value of the balanced transmission line decreases, the greater the amplitude of the reflected wave.

As shown in Figure 11c, the received reflected wave can be superimposed with the incident wave to form a result signal. If the amplitude of the incident wave is 1, the amplitude of the result signal is 1-X, and subsequent steps can be based on the amplitude of the result signal. 1-X, calculate the current bending angle of the folding screen.

Please refer to Figures 12a-12c. Figures 12a-12c are schematic diagrams of a set of folding screens provided by embodiments of the present application in a cracked state.

As shown in Figure 12a, when there is a crack in the folding screen, the upper metal line and/or the lower metal line in the balanced transmission line will also be broken to a certain extent (the upper metal line is broken in Figure 12a as an example). Please also refer to Figure 12b. Figure 12b is the equivalent circuit of the balanced transmission line when there is a crack in the folding screen. As shown in Figure 12b, the resistance and inductance of the balanced transmission line at the crack position change, respectively, R' and L'. Balanced The impedance value Z of the transmission line in the fracture area increases accordingly.

Please refer to Figure 12c. When there is a crack in the folding screen, a transient excitation signal (such as the above-mentioned first pulse signal) is input at the starting end, that is, the incident wave in Figure 12c. When the incident wave propagates to the crack position (that is, the impedance value changes node), it will form into a corresponding reflected wave (such as the above-mentioned second reflected signal), and the reflected wave has a positive polarity (that is, the phase of the incident wave is the same). The amplitude of the reflected wave may be Y, and the more the impedance value of the balanced transmission line decreases, the greater the amplitude of the reflected wave.

As shown in Figure 12c, the received reflected wave can be superimposed with the incident wave to form a result signal. If the amplitude of the incident wave is 1, then the amplitude of the result signal is 1+Y, and subsequent steps can be based on the amplitude of the result signal. 1+Y, calculate the current crack severity of the folding screen, and calculate the crack position based on the return time of the reflected wave (for example, the time difference between transmitting the incident wave and receiving the reflected wave).

Please refer to FIG. 13 , which is a schematic flowchart of a manufacturing method of a folding screen auxiliary device provided by an embodiment of the present application. The identification of bending angles and cracks based on time domain reflection technology provided by this application is mainly realized through the structure of a balanced transmission line (also called a microstrip balanced transmission line or a microstrip signal line) embedded inside the panel, in which the lower metal The lines use source/drain (SD) wiring Ti/Al/Ti (titanium/aluminum/titanium) metal, the intermediate dielectric layer uses PLN or pixel definition layer (PDL) organic matter, and the upper metal The lines use anode ITO/AG/ITO (indium tin oxide/silver/indium tin oxide) or the metal wiring of the touch layer (Touch On Encapsulation, TOE) above the packaging layer. Among them, the SD trace is the metal plating trace connecting the source and drain of the pixel drive MOS tube on the panel, usually Ti/Al/Ti; TOE is the touch layer made on the packaging layer, which is used to realize touch Functional plating. As shown in Figure 13, the method includes the following steps S1301 to S1304.

Step S1301, etching is performed on the substrate to form a trench.

Specifically, please refer to Figures 14a to 14f. Figures 14a to 14f are schematic diagrams of the manufacturing process of a set of folding screen auxiliary devices provided by embodiments of the present application. As shown in Figure 14a, the substrate can mainly include gate insulation 2 (GI2) & interlayer dielectric (ILD) [03], barrier layer (barrier) & GI1 [ 02], polyimide (polyimide, PI) substrate (substrate) [01].

Optionally, the preparation process of the substrate may include the following steps S1 to S12:

Step S1: Prepare a glass substrate. After cleaning the glass substrate, perform PI coating and curing to form the PI substrate [01] shown in Figure 14a. Its thickness can be 10±1um.

Step S2, use PECVD technology to deposit a barrier and a-Si (amorphous silicon) film layer on the PI substrate [01]. The barrier is a SiO2 film layer with a thickness of 650nm and a-Si thickness of 5nm. Subsequently, it can Absorbs laser lift off (LLO) energy to prevent damage to thin film transistor (TFT).

Step S3, continue to coat the PI substrate [01], the thickness can also be 10±1um.

Step S4, use PECVD technology to deposit a buffer and insulation layer (buffer) on the PI substrate [01]. The buffer layer is a composite film layer of SiNx and SiO2. The thickness can be 200nm and 350nm respectively, which can be used for subsequent excimer laser annealing (excimer The laser annealing (ELA) process provides thermal insulation.

Step S5, use PECVD to deposit an amorphous silicon layer, and perform dehydrogenation treatment (the temperature can be about 450°C, the duration can be about 2 hours), and then the ELA process is performed to realize the conversion of amorphous silicon to polycrystalline silicon.

Step S6: Expose, develop and etch the polysilicon to realize patterning of TFT channels and wiring.

Step S7, use PECVD to deposit a GI1 film layer. The material is a SiO2 film layer, the thickness can be 120 nm, and it functions as a gate insulating layer. At this point, barrier&GI1[02] shown in Figure 14a is obtained.

Step S8, use Sputter technology to deposit the gate1 (gate of the thin film transistor) film layer. The material is Mo (molybdenum) metal, and the thickness can be 220nm. Then, exposure, development and etching are performed to form the gate and capacitor electrode patterns, which can serve as TFT gate and the bottom electrode of the capacitor.

Step S9, use PECVD to deposit a GI2 film layer, the material is a SiNx film layer, the thickness can be 130nm, and it functions as a capacitor dielectric layer.

Step S10, use Sputter technology to deposit the gate2 film layer. The material is Mo metal and the thickness can be 220nm. Then, exposure, development and etching are performed to form the upper electrode of the Cst (storage capacitor) capacitor.

Step S11, use PECVD technology to deposit ILD. ILD is a composite film layer, with a SiO2 film layer below and a thickness of 300nm, and a SiNx film layer above and a thickness of 200nm. Then carry out hydrogenation treatment (the temperature can be about 350°C and the duration can be about 2 hours) to repair the dangling bonds on the polysilicon surface. At this point, GI2&ILD[03] shown in Figure 14a is obtained.

Step S12, after ILD deposition, a dry etching process is used to etch the ILD via holes in the pixel area (array area, AA) to form a crack dam [05] to prevent the expansion of laser cutting cracks as shown in Figure 14a. The isolation cracks extend into the display area. At this point, the substrate in step S1301 is obtained. Optionally, as shown in Figure 14a, laser cutting can be used to segment the panel. Generally speaking, this laser cutting technology is mostly performed after the entire Panel process is completed to separate the entire panel (including multiple small panels). panel individual) is divided into multiple independent individual units.

Optionally, etching (that is, performing a groove process) on the substrate as shown in Figure 14a forms a trench [04]. The specific position and depth of the trench [04] can be shown in Figure 14a, where the depth of the trench [04] can be 1-1.5um, the bottom width of the trench [04] can be 10-15um, and the trench [04] can be 10-15um. 04] The distance between the bottom edge and the edge of the substrate can be 200-250nm.

Step S1302, deposit a second conductive layer at the bottom of the trench.

Specifically, after the trench [04] is formed, SD traces are deposited at the bottom of the trench [04]. The material is Ti/Al/Ti metal to form the second conductive layer [06] as shown in Figure 14b (i.e., balanced lower metal line in the transmission line) and the remainder of the trench [07]. Among them, the thickness of each metal layer of Ti/Al/Ti in the second conductive layer [06] can be 50/650/50nm. As shown in Figure 14b, the trace width of the second conductive layer [06] is about 8-10um.

Step S1303, deposit and form a dielectric layer on the remaining portion of the trench.

Specifically, as shown in Figure 14c, after the second conductive layer [06] is prepared, PLN can be coated and patterned to form a dam (dam) that blocks the overflow of the ink jet printing layer (ink jet printer dam, IJP). )[09] and [10] and AA area structure. At the same time, as shown in Figure 14c, PLN can be filled into the remaining part of the trench [07], thereby forming a dielectric layer between the upper and lower metal lines in the balanced transmission line [08].

Step S1304, deposit a first conductive layer on the dielectric layer.

Specifically, as shown in Figure 14d, after the dielectric layer [08] is prepared, ITO/AG/ITO metal can be deposited on the dielectric layer [08] to form the first conductive layer [11] (i.e., the first conductive layer [11] in the balanced transmission line). upper metal line, that is, the light-emitting anode) to form an upper electrode in the TDR capacitor area (or you can also use TOE TxRx wiring as the upper electrode). Among them, the thickness of each metal layer of ITO/AG/ITO in the first conductive layer [11] can be 7/100/7nm. As shown in Figure 14d, the trace width of the first conductive layer [11] is about 8-10um.

At this point, the production of the balanced transmission line has been completed during the normal lamination process of the panel. No additional steps and processes are required. The process is simple, the cost is low, and the thickness and weight of the entire machine are not increased. Moreover, as mentioned above, the line width of the upper and lower metal lines in the balanced transmission line is only 8-10um, which does not affect the extremely narrow frame of the screen.

Optionally, after completing the preparation of the first conductive layer [11], the PDL/pixel support layer (pixel spacer, PS) coating and patterning can be continued to form a pixel definition area and a PS support area in the AA area, and at the edge Position complete IJP dam pattern. Subsequently, the preparation of the TFE encapsulation layer can be continued to form a TPE layer [12] as shown in Figure 14e, where the TPE layer [12] can include a chemical vapor deposition layer (Chemical Vapor Deposition, CVD) 1, IJP, and CVD2, which The thickness of each layer can be 0.8-1um, 8-10um, and 0.7-0.9um respectively. Further, after the TPE layer [12] is completed, continue to prepare as shown in Figure 14e TOE layer [13], and complete the preparation of TOE TxRx [14] shown in Figure 14e. As shown in Figure 14f, the OC layer [15] is finally coated, and the panel process and structure are now complete.

In summary, the embodiments of the present application provide a solution based on balanced transmission lines and using the principle of time domain reflection to identify the bending angle of a folding screen, that is, cracks in the screen. Compared with the traditional solution that adds external sensors (such as Hall sensors or flexible pressure sensors) or antenna patches to identify the bending angle of the folding screen, thereby increasing the thickness, weight and manufacturing cost of the entire machine, this solution In the application embodiment, a balanced transmission line can be directly embedded in the stack during the preparation of the folding screen. Subsequently, based on the time domain reflection technology and the impedance value change characteristics of the balanced transmission line, the bending angle of the folding screen can be quickly and accurately detected. It has strong anti-interference ability, high detection sensitivity, does not increase the thickness and weight of the whole machine, has low cost and simple process, and meets the actual needs of users to a great extent.

Please refer to Figure 15. Figure 15 is a schematic flowchart of a folding screen assistance method provided by an embodiment of the present application. This folding screen assistance method can be applied to an electronic device (such as the electronic device 100 shown as an example in Figure 7 or Figure 9). The electronic device includes a folding screen, and the folding screen includes a balanced transmission line and a time domain reflection technology TDR module; balanced The transmission line includes a first conductive layer, a dielectric layer and a second conductive layer stacked in sequence; the first end of the first conductive layer is connected to the TDR module, and the first end of the second conductive layer is connected to the ground. The folding screen assistance method may include the following steps S1501 to S1504.

Step S1501: Receive the first pulse signal transmitted by the TDR module through the first conductive layer.

Step S1502: When the folding screen is bent, the thickness of the bending area of the dielectric layer is reduced from the first thickness to the second thickness, and a corresponding first reflection signal is formed based on the first pulse signal through the first conductive layer, and the first reflection signal is transmitted. One reflects the signal to the TDR module.

Step S1503: Determine the bending angle of the folding screen based on the first pulse signal and the first reflection signal through the TDR module.

Optionally, for the folding screen assistance method, reference may be made to the description of the corresponding embodiments in FIGS. 7 to 14f mentioned above, which will not be described again here.

Optionally, each method process in the battery-assisted method described in the embodiments of this application can be implemented based on software, hardware, or a combination thereof. Among them, the hardware implementation may include logic circuits, algorithm circuits or analog circuits, etc. Implementation in software may include program instructions, which may be regarded as a software product that is stored in a memory and may be run by a processor to implement related functions.

Embodiments of the present application also provide a computer-readable storage medium, wherein the computer-readable storage medium can store a program. When the program is executed by a processor, the processor can perform any of the steps described in the above method embodiments. Some or all of the steps of a.

An embodiment of the present application also provides a computer program. The computer program includes instructions. When the computer program is executed by a multi-core processor, the processor can execute some or all of the steps described in any of the above method embodiments. .

In the above embodiments, the description of each embodiment has its own emphasis. If there is no detailed description in a certain embodiment, you may See related descriptions of other embodiments. It should be noted that for the sake of simple description, the foregoing method embodiments are expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence. Because according to this application, certain steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily necessary for this application.

In the several embodiments provided in this application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the above units is only a logical function division. In actual implementation, there may be other divisions. For example, multiple units or components may be combined or integrated. to another system, or some features can be ignored, or not implemented. On the other hand, the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the devices or units may be in electrical or other forms.

The units described above as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or software functional units.

If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or contributes to the existing technology, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to cause a computer device (which can be a personal computer, a server or a network device, etc., specifically a processor in a computer device) to execute all or part of the steps of the above methods in various embodiments of the present application. Among them, the aforementioned storage media can include: U disk, mobile hard disk, magnetic disk, optical disk, read-only memory (read-only memory, ROM), double-rate synchronous dynamic random access memory (double data rate, DDR), flash memory ( Flash) or random access memory (RAM) and other media that can store program code.

As mentioned above, the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still make the foregoing technical solutions. The technical solutions described in each embodiment may be modified, or some of the technical features may be equivalently replaced; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions in each embodiment of the present application.

Claims

A folding screen auxiliary device, characterized in that it is applied to folding screens; the device includes a balanced transmission line, the balanced transmission line includes a first conductive layer, a dielectric layer and a second conductive layer stacked in sequence; the first conductive layer The first end is connected to the time domain reflection technology TDR module, and the first end of the second conductive layer is grounded;

The first conductive layer is used to receive the first pulse signal transmitted by the TDR module;

When the folding screen is bent, the thickness of the bending area of the dielectric layer is reduced from the first thickness to the second thickness, and the first conductive layer is also used to form a corresponding first thickness based on the first pulse signal. Reflect the signal and transmit the first reflected signal to the TDR module;

The TDR module is used to determine the bending angle of the folding screen based on the first pulse signal and the first reflection signal.
The device according to claim 1, wherein when the folding screen cracks, the first conductive layer and/or the second conductive layer breaks, and the first conductive layer is also used for Form a corresponding second reflection signal based on the first pulse signal, and transmit the second reflection signal to the TDR module;

The TDR module is also used to determine the crack size and crack position of the folding screen based on the first pulse signal and the second reflection signal.
The device according to claim 2, wherein the TDR module includes a transmitting circuit and a receiving circuit, and the transmitting circuit and the receiving circuit are respectively connected to the first end of the first conductive layer;

The transmitting circuit is used to transmit the first pulse signal to the first conductive layer;

The receiving circuit is configured to receive the first reflection signal transmitted by the first conductive layer; and, based on the amplitude difference between the first pulse signal and the first reflection signal, determine the folding The bending angle of the screen.
The device according to claim 3, characterized in that the receiving circuit is also used to:

receiving the second reflected signal transmitted by the first conductive layer;

Determine the crack size of the folding screen based on the amplitude difference between the first pulse signal and the second reflection signal, and based on the difference between the emission of the first pulse signal and the reception of the second reflection signal. time difference to determine the crack position of the folding screen.
The device according to claim 4, wherein the amplitude of the first reflected signal and the second reflected signal is smaller than the amplitude of the first pulse signal; the phase of the first reflected signal is different from the amplitude of the first reflected signal. The phase of the first pulse signal is opposite, and the phase of the second reflected signal is the same as the phase of the first pulse signal.
The device according to any one of claims 1 to 5, wherein the first conductive layer includes a first metal layer, a second metal layer and a third metal layer stacked in sequence, and the first metal layer and The material of the third metal layer is Ti, and the material of the second metal layer is Al; the second conductive layer includes a fourth metal layer, a fifth metal layer and a sixth metal layer stacked in sequence; The material of the fourth metal layer and the sixth metal layer is ITO, and the material of the fifth metal layer is Ag.
The device according to any one of claims 1-6, wherein the second end of the first conductive layer and the The second end of the second conductive layer is respectively connected to both ends of the balancing resistor, and the resistance value of the balancing resistor is equal to the impedance value of the balanced transmission line.
The device according to claim 7, characterized in that the impedance value of the balanced transmission line satisfies the following formula:

Wherein, Z is the impedance value of the balanced transmission line, Er is the dielectric constant of the dielectric layer, H is the thickness of the dielectric layer, and W is the wiring of the first conductive layer and the second conductive layer. Width, T is the wiring thickness of the first conductive layer and the second conductive layer; Ln is the natural logarithm.
The device according to any one of claims 1 to 8, characterized in that the folding screen includes a sequentially stacked optical organic coating, a touch TOE layer on the encapsulation layer, a thin film encapsulation TFE layer, and a second gate electrode. Insulating layer, first gate insulating layer and polyimide PI substrate; the balanced transmission line is embedded in the TFE layer, the second gate insulating layer and the first gate insulating layer.
A method of manufacturing a folding screen auxiliary device, characterized in that the method includes:

Etch the substrate to form trenches;

Deposit a second conductive layer at the bottom of the trench; the orthographic projection of the second conductive layer on the substrate is smaller than the orthographic projection of the trench on the substrate; in a direction perpendicular to the substrate on, the thickness of the second conductive layer is smaller than the thickness of the trench;

Deposit and form a dielectric layer on the remaining portion of the trench;

A first conductive layer is deposited on the dielectric layer; the orthographic projection of the first conductive layer on the substrate is smaller than the orthographic projection of the dielectric layer on the substrate.
The method of claim 10, wherein the substrate includes a second gate insulating layer, a first gate insulating layer and a polyimide PI substrate that are stacked in sequence.
The method according to claim 10 or 11, characterized in that depositing a first conductive layer on the dielectric layer includes:

A third metal layer, a second metal layer and a first metal layer are sequentially deposited on the dielectric layer; the material of the first metal layer and the third metal layer is Ti, and the material of the second metal layer is Al.
The method according to any one of claims 10-12, wherein depositing a second conductive layer at the bottom of the trench includes:

A sixth metal layer, a fifth metal layer and a fourth metal layer are sequentially deposited at the bottom of the trench; the material of the fourth metal layer and the sixth metal layer is ITO, and the material of the fifth metal layer is ITO. Ag.
The method according to any one of claims 10 to 13, characterized in that the first end of the first conductive layer is respectively connected to the transmitting circuit and the receiving circuit in the time domain reflection technology TDR module, and the second conductive layer The first end of the layer is grounded; the second end of the first conductive layer and the second end of the second conductive layer are respectively connected to both ends of the balancing resistor, and the resistance of the balancing resistor is the same as that of the first conductive layer. The impedance values of the balanced transmission lines composed of the second conductive layer, the dielectric layer and the second conductive layer are equal.
The device according to claim 14, characterized in that the impedance value of the balanced transmission line satisfies the following formula:

Wherein, Z is the impedance value of the balanced transmission line, Er is the dielectric constant of the dielectric layer, H is the thickness of the dielectric layer, and W is the wiring of the first conductive layer and the second conductive layer. Width, T is the wiring thickness of the first conductive layer and the second conductive layer; Ln is the natural logarithm.
A folding screen auxiliary device, characterized in that it is applied to folding screens, and the device includes a balanced transmission line and a TDR module as described in any one of claims 1 to 9 above.
An electronic device, characterized in that the electronic device includes a folding screen, and the folding screen includes the device as described in any one of claims 1 to 9 above.