WO2024078276A1

WO2024078276A1 - Touch detection method and apparatus, interactive tablet and storage medium

Info

Publication number: WO2024078276A1
Application number: PCT/CN2023/119734
Authority: WO
Original assignee: 广州显创科技有限公司
Priority date: 2022-10-12
Filing date: 2023-09-19
Publication date: 2024-04-18
Also published as: CN117873338A

Abstract

A touch detection method and apparatus, an interaction tablet and a storage medium, capable of solving the technical problem in related technologies that false detection is prone to occurring in detection of a touch operation by using an optical detection method. Light emitted by a light emitter of an optical detection unit (12, 42) of the interactive tablet covers the surface of a display screen (1, 40) of the interactive tablet and is received by a light receiver of the optical detection unit (12, 42). A first sensor (131) of a touch state detection unit (13, 43) of the interactive tablet is arranged on the side of the display screen (1, 40) facing away from a user. The optical detection unit (12, 42) determines an occlusion data signal according to a light signal currently received and reports same to a processing unit (14, 41); the touch state detection unit (13, 43) performs multi-stage amplification on an original signal collected by the first sensor (131) in real time and when determining that the display screen (1, 40) receives a sensing signal, generates a touch state signal and reports same to the processing unit (14, 41); and the processing unit (14, 41) generates an occlusion state signal according to the occlusion data signal and determines, according to the occlusion state signal and the touch state signal, that a touch operation is received.

Description

Touch detection method, device, interactive tablet and storage medium

This application claims priority to a Chinese patent application filed with the Chinese Patent Office on October 13, 2022, with application number 202211249600.2 and invention name “Touch detection method, device, interactive tablet and storage medium”, the entire contents of which are incorporated by reference in this application.

Technical Field

The embodiments of the present application relate to the field of touch control technology, and in particular to a touch detection method, device, interactive tablet and storage medium.

Background technique

With the development of touch technology, various electronic devices with touch functions have appeared in people's daily lives, such as smart phones, tablet computers, interactive tablets, etc. When using electronic devices, users use touch technology to manipulate the content on the display screen to control the electronic devices. At this time, accurately detecting the user's touch operation on the display screen is the key link in realizing touch technology.

The optical detection method is one of the more commonly used touch detection methods. The principle of the optical detection method is: a light network composed of light is covered on the surface of the display screen. When the display screen receives a touch operation, the touch object will block the light on the surface of the display screen. At this time, the electronic device can detect the touch operation and determine the touch position of the touch operation according to the light blocking situation, and then respond according to the touch position. In the related art, due to the limitation of hardware conditions, the light cannot completely fit the surface of the display screen, that is, the light covered by the surface of the display screen has a certain distance from the surface of the display screen. At this time, no matter whether the touch object actually touches the display screen, as long as the light is blocked, the electronic device will think that the touch operation is detected. In this way, false detection will occur, and the electronic device will make a false response to the falsely detected touch operation.

Summary of the invention

The embodiments of the present application provide a touch detection method, device, interactive tablet and storage medium to solve the technical problem of false detection that is prone to occur when using optical detection methods to detect touch operations in related technologies.

In a first aspect, an embodiment of the present application provides a touch detection method, which is applied to an interactive tablet, wherein the interactive tablet includes a display screen, a processing unit, an optical detection unit, and a touch state detection unit, wherein the optical detection unit includes a light transmitter and a light receiver, wherein each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver, and the touch state detection unit includes at least one first sensor, wherein the first sensor includes a mechanical A sensor or a vibration sensor, wherein the first sensor is arranged on a side of the display screen facing away from the user;

The touch detection method comprises:

The optical detection unit determines a shielding data signal according to the light signal received by the light receiver and reports the shielding state signal to the processing unit;

The touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time, and determines based on the multi-stage amplified signal that when the surface of the display screen receives the sensing signal, generates a touch state signal, and reports the touch state signal to the processing unit;

The processing unit generates an occlusion state signal according to the occlusion data signal, and determines whether the display screen receives a touch operation according to the occlusion state signal and the touch state signal.

In a second aspect, an embodiment of the present application provides a touch detection method, which is applied to an interactive tablet, wherein the interactive tablet includes a display screen, a processing unit, an optical detection unit, and a touch state detection unit, wherein the optical detection unit includes a light transmitter and a light receiver, wherein each light beam emitted by the light transmitter covers a surface of the display screen and is received by the light receiver, and wherein the touch state detection unit includes at least one first sensor, wherein the first sensor includes a mechanical sensor or a vibration sensor, and wherein the first sensor is disposed on a side of the display screen facing away from a user;

The touch detection method comprises:

The optical detection unit determines a shielding data signal according to the light signal received by the light receiver and reports the shielding data signal to the processing unit;

The touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time, and sends the multi-stage amplified signal to the processing unit;

The processing unit generates an occlusion state signal according to the occlusion data signal, generates a touch state signal when determining that the surface of the display screen receives a sensing signal according to the amplified signal, and determines that the display screen receives a touch operation according to the occlusion state signal and the touch state signal.

In a third aspect, an embodiment of the present application further provides a touch detection device, which is applied to an interactive tablet, wherein the interactive tablet comprises a display screen, a processing unit, an optical detection unit, and a touch state detection unit, wherein the optical detection unit comprises a light transmitter and a light receiver, wherein each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver, wherein the touch state detection unit comprises at least one first sensor, wherein the first sensor comprises a mechanical sensor or a vibration sensor, and wherein the first sensor is disposed on a side of the display screen facing away from the user;

The touch detection device comprises:

A first detection module, configured in the optical detection unit, for determining a shielding data signal according to the light signal received by the light receiver and reporting the shielding data signal to the processing unit;

a second detection module, configured in the touch state detection unit, for performing multi-stage amplification on the original signal collected by the first sensor in real time, and determining based on the multi-stage amplified signal that the surface of the display screen receives the sensing signal, generating a touch state signal, and reporting the touch state signal to the processing unit;

A third detection module is configured in the processing unit, and is used to generate the blocking state signal according to the blocking data signal, and determine whether the display screen receives a touch operation according to the blocking state signal and the touch state signal.

In a fourth aspect, an embodiment of the present application provides a touch detection device, which is applied to an interactive tablet, wherein the interactive tablet includes a display screen, a processing unit, an optical detection unit, and a touch state detection unit, wherein the optical detection unit includes a light transmitter and a light receiver, wherein each light beam emitted by the light transmitter covers a surface of the display screen and is received by the light receiver, and wherein the touch state detection unit includes at least one first sensor, wherein the first sensor includes a mechanical sensor or a vibration sensor, and wherein the first sensor is disposed on a side of the display screen facing away from a user;

The touch detection device comprises:

a ninth detection module, configured in the optical detection unit, for determining a shielding data signal according to the light signal received by the light receiver and reporting the shielding data signal to the processing unit;

a tenth detection module, configured in the touch state detection unit, for performing multi-stage amplification on the original signal collected in real time by the first sensor, and sending the multi-stage amplified signal to the processing unit;

An eleventh detection module is configured in the processing unit, and is used to generate the occlusion status signal according to the occlusion data signal, determine according to the amplified signal that a touch status signal is generated when the surface of the display screen receives the sensing signal, and determine that the display screen receives a touch operation according to the occlusion status signal and the touch status signal.

In a fifth aspect, an embodiment of the present application further provides an interactive tablet, comprising a display screen, a processing unit, an optical detection unit and a touch state detection unit, wherein the optical detection unit comprises a light transmitter and a light receiver, wherein each light beam emitted by the light transmitter covers a surface of the display screen and is received by the light receiver, and wherein the touch state detection unit comprises at least one first sensor, wherein the first sensor comprises a mechanical sensor or a vibration sensor, and wherein the first sensor is disposed on a side of the display screen facing away from a user;

The optical detection unit is used to determine the shielding data signal according to the light signal received by the light receiver and report the shielding data signal to the processing unit;

The touch state detection unit is used to perform multi-stage amplification on the original signal collected by the first sensor in real time, and to generate a touch state signal when determining that the surface of the display screen receives the sensing signal based on the multi-stage amplified signal, and report the touch state signal to the processing unit;

The processing unit is used to generate an occlusion state signal according to the occlusion data signal, and determine whether the display screen receives a touch operation according to the touch state signal and the touch state signal.

In a sixth aspect, an embodiment of the present application further provides an interactive tablet, comprising a display screen, a processing unit, an optical detection unit, and a touch state detection unit, wherein the optical detection unit comprises a light emitter and a light receiver, wherein each light emitted by the light emitter covers a surface of the display screen and is received by the light receiver, and the touch state detection unit comprises at least one first sensor, wherein the first sensor comprises a mechanical sensor or a vibration sensor, and the first sensor is disposed on a side of the display screen away from a user;

The touch state detection unit is used to perform multi-stage amplification on the original signal collected by the first sensor in real time, and send the multi-stage amplified signal to the processing unit;

The processing unit is used to generate the occlusion status signal according to the occlusion data signal, determine according to the amplified signal that the surface of the display screen receives the sensing signal and generate a touch status signal, and determine according to the occlusion status signal and the touch status signal that the display screen receives a touch operation.

In the seventh aspect, an embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the touch detection method as described in the first aspect or the touch detection method as described in the second aspect.

In one embodiment of the present application, an optical detection unit detects the reception of light covering the surface of the display screen and reports an occlusion data signal to a processing unit. The touch state detection unit performs multi-stage amplification on the original signal collected in real time by the first sensor set on the back of the display screen, and determines that the surface of the display screen receives the sensing signal based on the multi-stage amplified signal, and reports a touch state signal to the processing unit. The processing unit generates an occlusion state signal according to the occlusion data signal, and determines that the display screen receives a touch operation according to the occlusion state signal and the touch state signal. The technical means solves the technical problem of easy misdetection when using optical detection means to detect touch operations in related technologies. On the basis of optical detection, a first sensor is added, wherein the first sensor is a mechanical sensor or a vibration sensor set on the side of the display screen away from the user, so as to detect the force or vibration generated when the display screen is touched, overcomes the misdetection problem caused by a certain distance between the light and the surface of the display screen, and improves the detection accuracy. In addition, by multi-stage amplification of the original signal collected by the first sensor, it can be ensured that the signal changes caused by the touch operation contacting the display screen with different forces and different speeds can be amplified to a reasonable signal-to-noise ratio, ensuring the accuracy of the touch state signal, thereby further improving the detection accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a touch detection method provided by an embodiment of the present application;

FIG2 is a flow chart of a touch detection method provided by an embodiment of the present application;

FIG3 is a front view of a display screen provided by an embodiment of the present application;

FIG4 is a schematic diagram of the back side of a display screen provided by an embodiment of the present application;

FIG5 is a schematic diagram of a writing trajectory provided by an embodiment of the present application;

FIG6 is a schematic diagram of a writing trajectory provided by an embodiment of the present application;

FIG7 is a flow chart of a touch detection method provided by an embodiment of the present application;

FIG8 is a schematic structural diagram of a touch detection device provided by an embodiment of the present application;

FIG9 is a schematic diagram of the structure of a touch detection device provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of the structure of an interactive tablet provided by an embodiment of the present application.

Detailed ways

The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only the parts related to the present application, rather than all structures, are shown in the accompanying drawings.

In the related art, the optical touch detection system is the main hardware device for implementing the optical detection method. The optical touch detection system is usually composed of a display screen, an optical touch sensor and an optical processing unit, wherein the optical touch sensor is composed of a transmitting part and a receiving part, wherein the transmitting part includes a plurality of light transmitters, and the receiving part includes a plurality of light receivers. The optical touch sensor is installed at the edge of the display screen (such as the transmitting part and the receiving part are symmetrically arranged at the two ends of the display screen, and the transmitting part is arranged at the two edges of the display screen and the receiving part is symmetrically arranged at the other two edges of the display screen). Each light transmitter of the transmitting part works according to a set frequency, that is, a plurality of light rays are emitted according to the set frequency, and each light ray can be received by a corresponding light receiver, and the light network formed by all the emitted and received light rays covers the surface of the display screen, wherein the surface of the display screen can be understood as the surface where the imaging screen is located, and when the user touches the display screen to interact, it mainly touches the surface of the display screen. After each light transmitter and each light receiver work together, the surface of the display screen is scanned by light to scan the touch object contacting the display screen. It can be understood that the type of light emitted by the light transmitter is not currently limited, for example, the light transmitter emits infrared light.

The optical processing unit is used to analyze the light obstruction situation. The optical processing unit can be set inside the electronic device used in the optical touch detection system. The optical processing unit can be a microcontroller unit (MCU) that matches the optical touch sensor. For example, the optical processing unit adopts the 811 system on chip (SOC). When the optical processing unit analyzes the light obstruction situation, it is mainly achieved by analyzing the light energy of the light. It can be understood that when a touch object (an object used by the user to perform touch, such as a touch pen (also recorded as a writing pen, stylus, smart pen, etc.) or a user's finger, etc.) contacts the display screen, the touch object will block multiple light rays covering the surface of the display screen. At this time, since the light is blocked, Therefore, the light energy of the light received by the corresponding light receiver will change, that is, the light energy of the light received by the corresponding light receiver when the light is blocked is less than the light energy of the light received by the light receiver when it is not blocked. At this time, the optical processing unit can analyze the blocking of the light according to the change of the light energy of the light, that is, determine which light is blocked, and then calculate the position of the touch object (generally reflected by two-dimensional coordinates), and can also calculate the width, length and/or area of the touch point (the touch area determined based on the blocked light). In addition, the light processing unit can also determine the time when the touch object is detected, etc. After that, the light processing unit forms touch point data (which can also be recorded as a touch data packet, including the position, width, length, area and/or detection time of the touch object, etc.), and reports the touch point data to the processor of the electronic device so that the processor can make further responses, that is, realize the touch function.

It should be noted that the processors of some electronic devices that use optical touch detection systems have the ability to analyze light obstruction. At this time, the optical processing unit can directly send the signals corresponding to each light currently scanned by the light touch sensor (reflecting light energy) to the processor of the electronic device, and the processor of the electronic device analyzes the light obstruction and calculates the position of the touch object, the time of detection, and the width, length and/or area of the touch point, and generates touch point data for further response. In some cases, when the processor of the electronic device takes on the calculation work of the optical processing unit, the optical touch detection system can also be composed of only a display screen and an optical touch sensor.

Optionally, a USB component is provided between the processor of the electronic device and the optical processing unit, such as a USB hub (USB HUB), a USB switching switch, a USB signal repeater (Redriver), etc. The processor of the electronic device can be used as a human interface device (Human Interface Device, HID). The processor of the electronic device and the optical processing unit communicate through the USB component, so that after the optical processing unit generates touch point data, the touch point data is transmitted to the processor of the electronic device through the USB component.

It can be understood that the optical touch sensor needs to be set in front of the edge of the display screen so that the light network it forms covers the surface of the display screen and ensures that the light transmission is unobstructed when there is no touch. Specifically, the optical touch sensor transmits light through a filter strip (also known as a filter), which is usually made by adding a dye to the raw material and then using an injection molding or casting process. The filter strip can pass the currently used light while filtering out other ambient light, thereby improving the signal-to-noise ratio of the light. Based on this method, when the optical touch sensor covers the light on the surface of the display screen, there is a certain distance between the light and the surface of the display screen, that is, the light touch sensor forms a touch area (that is, the area composed of the light network) in the vertical direction of the surface of the display screen, and the distance between the touch area and the surface is generally greater than 2mm (millimeter), so it cannot be ignored. At this time, when the touch object blocks the light, regardless of whether the touch object actually touches the display screen, the optical processing unit of the optical touch detection system will recognize the touch operation due to the light blocking situation, and then make the electronic device respond to the touch operation. For example, the vertical distance between the touch area and the display screen surface is recorded as H. In the writing scenario, during a writing process, the touch object first contacts the surface of the display screen and then moves away from the surface of the display screen after the writing is completed. Specifically, when writing starts, the touch object contacts the display screen. During the process, the object is first located above the touch area, that is, the vertical distance between the touch object and the surface of the display screen is greater than H. During this process, the optical processing unit will not detect the occlusion, and therefore, will not report the touch point data. Afterwards, when the touch object continues to move toward the display screen, it will first block the light, that is, the vertical distance between the touch object and the surface of the display screen is less than H but greater than 0. During this process, although the touch object has not touched the display screen, occlusion has occurred. Therefore, the optical processing unit will analyze the occlusion and report the touch point data, and the processor of the electronic device will respond based on the touch point data. After blocking the light, the touch object touches the display screen again, that is, the vertical distance between the touch object and the surface of the display screen is 0 or less than 0 (less than 0 means that the force generated when the touch object touches the display screen causes the surface of the display screen to be concave). During this process, the optical processing unit will still report the touch point data, and the processor of the electronic device will respond based on the touch point data. Afterwards, the touch object moves on the surface of the display screen, and the optical processing unit continues to report the touch point data. When writing is completed, the touch pen leaves the surface of the display screen first but still blocks the light, that is, the vertical distance between the touched object and the surface of the display screen is less than H but greater than 0. At this time, the optical processing unit will still report the touch point data, and the processor of the electronic device will respond based on the touch point data. Afterwards, the touch object leaves the touch area, that is, the vertical distance between the touch object and the surface of the display screen is greater than H. At this time, the optical processing unit cannot detect the obstruction, so it will no longer report the touch point data.

Based on the above content, it can be known that when the optical touch detection system detects touch operations based on light obstruction, it is easy to have false detection, especially when the touch object approaches and leaves the display screen, the false detection is more obvious, which causes the electronic device to respond incorrectly. Based on this, the embodiment of the present application provides a touch detection method, device, interactive tablet and storage medium, which comprehensively judges whether the display screen receives the touch operation based on the light obstruction and the force generated by the touch object when the touch object contacts the display screen, effectively avoiding the false detection that is easy to occur during optical detection and improving the detection accuracy of touch operations.

An embodiment of the present application provides a touch detection method, which can be executed by a touch detection device, which can be implemented by software and/or hardware, and which can be composed of two or more physical entities or one physical entity. The touch detection device can be an electronic device with touch function, such as an interactive tablet, a tablet computer, a smart TV, etc.

In one embodiment, the touch detection method is described by taking the touch detection device as an interactive tablet. The interactive tablet is an integrated device that uses touch technology to control the content displayed on the display tablet and realize human-computer interaction, and it integrates one or more functions such as a projector, an electronic whiteboard, a screen, a sound system, a television, and a video conferencing terminal.

In one embodiment, the interactive tablet includes a display screen, a processing unit, an optical detection unit and a touch state detection unit. The optical detection unit includes a light emitter and a light receiver. Each light beam emitted by the light emitter covers the surface of the display screen and is received by the light receiver. The touch state detection unit includes at least one first sensor. The first sensor includes a mechanical sensor or a vibration sensor. The first sensor is arranged on a side of the display screen facing away from the user.

Exemplarily, the interactive tablet is configured with at least one display screen. The size of the display screen is not currently limited. Generally speaking, The display screen is a large-size display screen, wherein the large-size display screen refers to a display screen that is larger than a set size (such as a set size of 40 inches or 44 inches, etc.). The display screen can be a liquid crystal display screen or other types of display screens.

The interactive tablet can detect touch operations acting on the surface of the display screen by optical detection, capacitive detection, electromagnetic detection and/or resistive detection. In one embodiment, the interactive tablet using optical detection is described as an example. Exemplarily, the optical detection unit refers to the device unit required to implement optical detection. The optical detection unit includes a light transmitter and a light receiver, wherein the installation positions of the light transmitter and the light receiver can refer to the installation positions of the light transmitter and the light receiver in the existing optical detection method. The type of light emitted by the light transmitter is not currently limited, such as emitting infrared type light. The light emitted by the light transmitter is received by the light receiver, and the light network formed by each light beam covers the surface of the display screen. It should be noted that the relevant description of the light transmitter and the light receiver can refer to the relevant description of the transmitting part and the receiving part in the optical touch detection system.

The touch state detection unit is used to detect the stress or vibration signal (also called acoustic signal) received on the surface of the display screen, wherein the stress can be understood as the stress (i.e., the force) generated when the touch object touches the display screen, which can be detected by a mechanical sensor, and the vibration signal can be understood as the vibration signal generated by the display screen when the touch object touches the display screen (vibration is achieved by the force generated during contact), which can be detected by a vibration sensor. The touch state detection unit includes at least one first sensor, and the first sensor includes a mechanical sensor or a vibration sensor. The first sensor is used to collect signals caused by the deformation of the display screen caused by the contact of the touch object. In one embodiment, when the first sensor is a mechanical sensor, the mechanical sensor collects stress signals corresponding to the stress on the surface of the display screen. It can be understood that since the stress generated when the touch object touches the display screen can be considered as pressure on the surface of the display screen, the mechanical sensor can also be understood as a pressure sensor. When the first sensor is a vibration sensor, the vibration sensor collects vibration signals on the surface of the display screen. In one embodiment, the first sensor is attached to the back of the glass panel of the display screen to ensure accurate collection of the stress received on the surface of the display screen or the vibration signal generated by the display screen when the touch object touches the display screen. Among them, the glass panel refers to a layer of glass provided in the display screen. When a touch object contacts the display screen, the glass panel receives the pressure (i.e. generates stress) caused by the contact of the touch object or generates vibration (with a small amplitude and does not affect the imaging of the display screen) based on the contact of the touch object. The back side refers to the side of the display screen that is away from the user when imaging, and can also be considered as the plane inside the interactive tablet. It should be noted that the bonding method and bonding position of the first sensor are not currently limited. Generally speaking, the acquisition range of the first sensor (which can be one first sensor or multiple first sensors) covers the entire display screen to ensure that no matter where on the surface of the display screen is touched by the touch object, the signal collected by the first sensor can reflect the operation of the current touch object. Optionally, the first sensor continues to collect data during the operation of the interactive tablet, that is, no matter whether there is a touch object on the surface of the display screen for touch operation, the first sensor will collect signals, but when the touch object is touching the surface of the display screen, the signal collected by the first sensor contains features related to the touch operation of the touch object. In one embodiment, the touch state detection unit also includes a touch detection processing subunit (also referred to as a signal processing unit), and the touch detection The touch detection processing subunit is used to process the signal collected by the first sensor to determine whether the surface of the display screen receives the touch of the touch object, and report the detection result of whether the touch is received to the processing unit of the interactive tablet. Among them, the touch detection processing subunit can be a chip or a processor (such as a microprocessor unit), etc. The touch detection processing subunit is located inside the interactive tablet and is connected to the processing unit of the interactive tablet. It should be noted that a component that ensures accurate signal transmission can also be provided between the touch detection processing subunit and the processing unit of the interactive tablet. It can be understood that in actual applications, if the processing unit of the interactive tablet has the ability to analyze the signal collected by the first sensor to determine whether the surface of the display screen receives the touch, there is no need to set the touch detection processing subunit. At this time, the signal collected by the first sensor is directly sent to the processing unit of the interactive tablet. In one embodiment, the touch state detection unit can also include other contents, such as a multi-stage amplification circuit to amplify the signal collected by the first sensor, so that the touch detection processing subunit processes a signal with more obvious characteristics.

The processing unit may be composed of one or more processors. In one embodiment, the processing unit includes at least a central processing unit (CPU) of the interactive tablet, and may also include a memory of the interactive tablet. The memory stores computer programs. The central processing unit can realize various functions of the interactive tablet by calling the computer programs stored in the memory. It can be understood that the lines used for transmitting signals between the processing unit and the optical detection unit and the touch state detection unit are internal lines of the interactive tablet, which are not explained separately at present. At least one type of operating system is installed in the central processing unit, and the operating system can be an Android system, a Windows system, or a Linux system. The interactive tablet installs at least one application under the operating system. Among them, the application can be an application that comes with the operating system, and an application downloaded from a third-party device or a server is also installed. There is no limitation at present. For example, the interactive tablet is installed with an application for writing, and the application can respond to touch operations when running, that is, draw corresponding writing tracks according to the touch operations. Optionally, the interactive tablet is also equipped with a communication unit, and the interactive tablet realizes the communication function through the communication unit. For example, the interactive tablet communicates data with the server through the communication unit. In addition, the interactive tablet can also be equipped with hardware devices such as speakers and microphones.

Optionally, the optical detection unit may further include an optical processing subunit, which may analyze the light blocking condition based on the light signal received by the light receiver, and generate touch point data to report to the processing unit so that the processing unit responds. Optionally, when the processing unit has the ability to analyze the light blocking condition, the optical processing subunit may only determine the blocked light and notify the processing unit of the currently blocked light, after which the processing unit generates the touch point data, or the optical processing subunit directly sends the light signal received by the light receiver to the processing unit, which analyzes the blocking condition and generates the touch point data.

The processing unit may also determine whether the display screen currently receives a touch operation based on the light shielding detection result obtained by the optical detection unit and the touch object touch detection result obtained by the touch state detection unit.

At this time, Figure 1 is a flow chart of a touch detection method provided by an embodiment of the present application. Referring to Figure 1, the interactive tablet performs the touch detection method including the following steps:

Step 110 : The optical detection unit detects the light signal received by the light receiver to determine the shielding data signal and reports the shielding data signal to the processing unit. Then, step 130 is executed.

Exemplarily, in the optical network formed by the cooperation of the light transmitter and the light receiver, each light has a corresponding number. During the operation of the interactive flat panel, the light receiver and the light transmitter continue to cooperate to continuously scan the surface of the display screen. At this time, the optical processing subunit of the optical detection unit continuously obtains each light signal received by the light receiver and can determine the number corresponding to each light signal. Afterwards, it is determined whether there is a blocked light according to each light signal. If there is a blocked light, the number of the blocked light and the scanning time corresponding to the blocked light are determined. Afterwards, the number of the blocked light and the corresponding scanning time are sent to the processing unit as a blocking data signal. Optionally, the light energy of the blocked light can also be sent to the processing unit. In this case, the optical detection unit will send the blocking data signal to the processing unit only when the blocked light is detected. Among them, the blocking determination method can be: the optical processing subunit calculates the light energy of each light signal received by the light receiver, and then determines whether the light is blocked according to the current light energy of each light signal and the light energy when there is no blocking. It can be understood that when light is blocked, the light energy of the light signal is significantly weakened. Therefore, a light energy weakening amount is preset (the specific value can be set according to actual needs). After the optical processing subunit determines the light energy of the received light signal, it calculates the difference between the light energy when it is not blocked and the light energy currently received. The difference can reflect the change of light energy. After that, the difference is compared with the preset light energy weakening amount. If the difference is greater than or equal to the light energy weakening amount, it is determined that the light corresponding to the difference is blocked. In this way, all blocked light can be found.

Alternatively, the light processing subunit continuously acquires each light signal received by each light receiver, and directly sends the light signal as an occlusion data signal to the processing unit. Alternatively, the light processing subunit continuously acquires each light signal received by each light receiver, and calculates the light energy of each light signal, and then sends the number and light energy of each light signal as an occlusion data signal to the processing unit. In this case, regardless of whether there is occlusion, the optical detection unit sends the occlusion data signal to the processing unit, so that the processing unit determines whether there is occlusion based on the occlusion data signal.

It should be noted that, in combination with the above content, it can be known that the occlusion data signal used in this step is generated based on the received light signal and is provided to the processing unit for processing, such as for the processing unit to determine the touch point data, the number of blocked light rays, the occlusion status signal, etc. It can be understood that in actual applications, in addition to the processing unit determining the relevant parameters related to the occlusion, the optical processing subunit can also determine the relevant parameters related to the occlusion based on the occlusion data signal and report it to the processing unit. At this time, the optical processing subunit no longer reports the occlusion data signal to the processing unit.

Step 120: The touch state detection unit amplifies the original signal collected by the first sensor in real time in multiple stages, and generates a touch state signal when determining that the surface of the display screen receives the sensing signal based on the multi-stage amplified signal, and reports the touch state signal to the processing unit. Execute step 130.

Exemplarily, during the operation of the touch state detection unit, the first sensor continuously collects signals, and the signals collected by the first sensor in real time are currently recorded as raw signals, wherein the raw signals are analog signals. Afterwards, the touch state detection unit analyzes and processes the raw signals to determine whether the surface of the display screen receives stress or whether vibration is generated based on touch. Currently, the signals representing stress or signals related to vibration are recorded as sensing signals, that is, when the surface of the display screen receives the sensing signal, it is considered that there is a touch object contacting the display screen. It can be understood that when the touch object contacts the surface of the display screen, the raw signal collected by the first sensor is significantly changed from the raw signal collected by the first sensor when the touch object does not contact the display screen, and the changed part can be considered as the part corresponding to the sensing signal. For example, when the first sensor is a mechanical sensor, when the touch object contacts the surface of the display screen, due to the stress generated during contact, the pressure received by the glass panel will change, and the raw signal collected by the mechanical sensor will also change (compared with the touch object not contacting the surface of the display screen).

Exemplarily, when the touch state detection unit determines whether the surface of the display screen receives the sensor signal based on the original signal, the original signal is first amplified to make the features related to the sensor signal in the original signal increase significantly. In one embodiment, when different touch objects contact the display screen, the touch speed and strength will be different. Therefore, the features related to the sensor signal in the original signal will have different changes. In order to accurately detect the sensor signal, the touch state detection unit performs multi-stage amplification on the original signal and records the amplified signal as the amplified signal. Among them, the multi-stage amplification is not a simple multiple amplification of the input, but amplifies the signal within the specified frequency range (which can be set in combination with actual conditions), and the signal outside the range is not amplified or the amplification scale is small. The purpose of this is to amplify the signal within the target range where the signal may exist, and the signal outside the range is regarded as noise and is not amplified, so as to achieve the purpose of suppressing noise. After multi-stage amplification, the amplified signal of the original signal at different amplification factors can be obtained. Optionally, the touch state detection unit is pre-set with multiple amplification levels, each amplification level has a corresponding amplification signal, and different amplification factors can be achieved by adjusting the amplification ratio of each amplification level. Optionally, the amplification ratio of each amplification level is preset and will not be changed during the operation of the touch state detection unit.

Exemplarily, the touch state detection unit includes a multi-stage amplification circuit, which performs multi-stage amplification on the original signal collected by the first sensor to obtain a multi-stage amplified signal. After that, the touch detection processing subunit receives the multi-stage amplified signal and determines whether the surface of the display screen receives the sensing signal based on the multi-stage amplified signal. The multi-stage amplification circuit can be designed according to actual needs. For example, the multi-stage amplification circuit uses a logarithmic amplifier to improve the detection sensitivity during amplification. When the number of amplification levels is 1-3, the multi-stage amplification circuit includes three logarithmic amplifiers. After the original signal passes through the first logarithmic amplifier, the amplified signal of the first stage is obtained. The amplified signal of the first stage is sent to the second logarithmic amplifier and the touch detection processing subunit respectively. After the second logarithmic amplifier processes, the amplified signal of the second stage is obtained. The amplified signal of the second stage is sent to the third logarithmic amplifier and the touch detection processing subunit respectively. After the third logarithmic amplifier processes, the amplified signal of the third stage is obtained. The amplified signal of the third stage is sent to the touch detection processing subunit. At this time, the touch detection processing subunit receives the multi-stage The three-stage amplified signal output by the amplifier circuit.

Since the features related to the sensing signal in the amplified signal are also amplified, the touch state detection unit can determine whether the surface of the display screen receives the sensing signal after identifying the features related to the sensing signal based on the multi-level amplified signal. For example, when the touch object contacts the surface of the display screen, due to the stress or vibration generated, the energy of the original signal collected by the first sensor is greater than the energy of the original signal collected by the first sensor when the touch object does not contact the surface of the display screen. Therefore, the energy value can be considered as a feature related to the sensing signal. In addition, other features can be set, and the touch state detection unit combines multiple features to determine whether the surface of the display screen receives the sensing signal.

When it is determined that the sensing signal is received, the touch state detection unit generates a touch state signal and reports the touch state signal to the processing unit, so that the processing unit determines that the touch state detection unit detects that the surface of the display screen is in contact with a touch object. Among them, the touch state signal is used to indicate that the surface of the display screen is currently detected to receive stress or generate vibration, that is, the touch state detection unit believes that a touch object is in contact with the surface of the display screen. It can be understood that the detection result obtained by the touch state detection unit based on the multi-level amplification signal includes two situations: one is that the surface of the display screen receives stress or generates vibration, and the corresponding detection result is to generate a touch state signal. At this time, the touch state signal can be represented by down; the other is that the surface of the display screen does not receive stress or generate vibration, and the touch state detection unit can generate a non-touch state signal to indicate that the surface of the display screen is not currently detected to receive stress or generate vibration (the first sensor includes a mechanical sensor or a vibration sensor, so receiving stress and generating vibration will not occur at the same time), that is, the touch state detection unit believes that there is no touch object in contact with the surface of the display screen, and at this time, the non-touch state signal can be represented by up. Taking the writing scene as an example, when the touch object writes on the surface of the display screen, the touch state detection unit determines that the sensing signal is received based on the real-time multi-level amplification signal, and continuously generates down and reports it to the processing unit. At this time, whether the touch object has just fallen (also called pen drop) and contacted the display screen surface or the touch object has already contacted the display screen surface and is moving on the surface, the touch state detection unit will generate down and report it to the processing unit. Optionally, the touch state detection unit determines that the surface of the current display screen has not received the sensing signal and does not report the corresponding up to the processing unit, or when the touch state detection unit determines that the surface of the display screen has not received the sensing signal, it reports the corresponding up to the processing unit, so that the processing unit determines that the touch state detection unit has not detected that the display screen surface has received stress or has not generated vibration.

In one embodiment, the touch state detection unit performs multi-stage amplification on the original signal, and can select a suitable amplified signal from the multi-stage amplified signal, and determine whether the surface of the display screen receives the sensing signal based on the selected amplified signal. At this time, the touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time, and generates a touch state signal when determining that the surface of the display screen receives the sensing signal based on the multi-stage amplified signal, which may include steps 121-123:

Step 121: The touch state detection unit performs multi-stage amplification on the original signal collected in real time by the first sensor to obtain multi-stage amplified signals.

The amplified signal is still an analog signal.

Step 122: The touch state detection unit selects a first-stage amplified signal from the multi-stage amplified signals.

Exemplarily, the touch state detection unit selects a first-stage amplified signal from the multi-stage amplified signal, and the selected amplified signal can be considered as an effective amplified signal, and an effective amplified signal means that the original signal is reasonably amplified and the details related to the sensing signal are basically retained. The selection process can be implemented by the touch detection processing subunit of the touch state detection unit.

In one embodiment, the touch state detection unit first converts the multi-stage amplified signal into a digital signal, and selects a first-stage amplified signal according to the overflow rate of the digital signal. Wherein, overflow means that when the analog signal is converted into a digital signal, the amplitude of the digital signal is greater than the quantization upper limit (i.e., upper) or less than the quantization lower limit (i.e., lower). For example, when a 10-bit ADC (i.e., analog-to-digital converter) is used for analog-to-digital conversion, the quantization upper limit is 1023 and the quantization lower limit is 0. During analog-to-digital conversion, when the amplitude of a certain signal point is greater than 1023, it can only be represented by 1023, and when the amplitude of a certain signal point is less than 0, it can only be represented by 0. This phenomenon is overflow, that is, overflow occurs due to the limit of the quantization bit number of the ADC. When overflowing, since the amplitude can only be represented by the corresponding quantization upper limit or quantization lower limit, some details in the amplified signal will be lost. Therefore, it is necessary to select a reasonable first-stage amplified signal in combination with the overflow of each stage of the amplified signal. Wherein, the overflow situation can be reflected by the overflow rate, and the overflow rate can reflect the completeness when converted into a digital signal. Each stage of the amplified signal has a corresponding overflow rate. The higher the overflow rate, the more details are lost when the amplified signal is converted into a digital signal. The lower the overflow rate, the less details are lost when the amplified signal is converted into a digital signal. It is understandable that insufficient amplification of the original signal is one reason for the low overflow rate. In this case, although fewer details are lost when the amplified signal is converted into a digital signal, the features related to the sensing signal in the amplified signal will not be significantly amplified. Therefore, the touch state detection unit can combine the overflow rates of the amplified signals at each level and select the amplified signal corresponding to a reasonable overflow rate. The amplified signal under this overflow rate can ensure that the lost details do not affect the signal accuracy, and can also ensure that the features related to the sensing signal are significantly amplified.

In one embodiment, the touch state detection unit may first select at least two amplified signals from the multi-level amplified signals, and then select a first-level amplified signal from the at least two amplified signals. Wherein, the amplification levels of the at least two amplified signals are continuous. It should be noted that the continuous amplification levels do not mean that the values corresponding to the amplification levels are continuous, but that the amplification levels of the at least two selected amplified signals are connected front and back in the multi-level amplification circuit. The specific value of the selected amplification level can be preset according to actual conditions. For example, the amplification level currently selected is 1-3 levels. At this time, the touch state detection unit selects amplified signals corresponding to levels 1, 2 and 3, and selects a certain level of amplified signals from them to detect whether the display screen surface receives the sensor signal. Optionally, if it is not possible to effectively determine whether the display screen surface receives the sensor signal based on the selected amplified signal, the touch state detection unit can reselect at least two amplified signals with different amplification levels (such as selecting amplified signals of levels 4-6), and continue to select a certain level of amplified signals from them to detect whether the display screen surface receives the sensor signal.

In one embodiment, when the overflow rate is used to select the amplified signal, step 122 includes steps 1221 to 1222:

Step 1221: The touch state detection unit determines the overflow rate of each stage of amplified signal.

Exemplarily, when the touch state detection unit performs analog-to-digital conversion on the amplified signal, the obtained digital signal is recorded as a digitized amplified signal. It can be understood that each level of amplified signal has a corresponding digitized amplified signal. Afterwards, the touch state detection unit determines the overflow rate according to the total number of signal points contained in the digitized amplified signal and the total number of overflowed signal points. At this time, step 1221 may include steps 12211-12213:

Step 12211: The touch state detection unit performs analog-to-digital conversion on each stage of the amplified signal to obtain a digitized amplified signal corresponding to each stage of the amplified signal.

In one embodiment, an analog-to-digital converter is used to convert the analog amplified signal into a processable digital amplified signal. The model of the analog-to-digital converter and the number of quantization bits set are not currently limited. At this time, the touch state detection unit may include an analog-to-digital converter, or the touch state detection unit may send the amplified signal to the analog-to-digital converter and receive the digital amplified signal fed back by the analog-to-digital converter.

Step 12212: The touch state detection unit counts the number of signal points whose signal values reach the quantization threshold in each stage of the digital amplified signal.

Exemplarily, the quantization threshold refers to the quantization upper limit and the quantization lower limit, and reaching the quantization threshold may include being greater than or equal to the quantization upper limit and less than or equal to the quantization lower limit. The signal value refers to the amplitude of the signal point during analog-to-digital conversion.

The digital amplified signal is composed of multiple digital signal points, each of which has a corresponding signal value. The total number of signal points is related to the length of the corresponding amplified signal and the sampling frequency during analog-to-digital conversion. Optionally, each time a signal point whose signal value reaches the quantization threshold appears, the touch state detection unit records the signal point, and then the touch state detection unit counts the number of signal points whose signal values reach the quantization threshold in the digital amplified signal.

Step 12213: The touch state detection unit determines the overflow rate of each stage of the digital amplified signal according to the number of signal points whose signal values reach the quantization threshold in each stage of the digital amplified signal and the total number of signal points of each stage of the digital amplified signal.

In one embodiment, the calculation formula of the overflow rate can be expressed as:

Where r represents the overflow rate, data_num represents the signal value of the signal point, sum represents addition, sum(data_num) represents the total number of signal points, data_num<=lower represents that the signal value of the signal point is less than or equal to the quantization lower limit, data_num>=upper represents that the signal value of the signal point is greater than or equal to the quantization upper limit, sum(data_num<=lower, data_num>=upper) represents the number of signal points whose signal value is less than or equal to the quantization lower limit and greater than or equal to the quantization upper limit, that is, the number of signal points that reach the quantization threshold. After sum(data_num<=lower, data_num>=upper) is divided by sum(data_num), the overflow rate can be obtained.

Optionally, an effective digital amplified signal refers to a signal that has been fully amplified and has little loss of details due to overflow. An effective digital amplified signal can amplify to the maximum extent while retaining features related to amplification. In one embodiment, the digital amplified signal that is insufficiently amplified (i.e., the amplification factor corresponding to the amplification level is too small) generally has an overflow rate of 0, i.e., each signal point has not overflowed. The digital amplified signal that is reasonably amplified (i.e., the amplification factor corresponding to the amplification level is reasonable) generally has an overflow rate between 0-10%. When the overflow rate is greater than 10%, it means that the digital amplified signal is over-amplified (i.e., the amplification factor corresponding to the amplification level is too large), and the signal loss is serious (more details are lost). Therefore, the validity of the digital amplified signal can be determined by the overflow rate. For example, a digital amplified signal with an overflow rate between 0-10% is regarded as a valid signal.

In one embodiment, after the touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time to obtain the multi-stage amplified signal, the method may include: the touch state detection unit selects a first number of amplified signals from the multi-stage amplified signal, the first number is at least two, and the first number of amplified signals are amplified signals with continuous amplification stages. After the touch state detection unit determines the overflow rate of each stage of the amplified signal, the method may include: when the touch state detection unit determines that the number of overflow rates exceeding the overflow rate range in the first number of amplified signals exceeds the second number, the first number of amplified signals is reselected, and the number of overflow rates exceeding the overflow rate range in the reselected amplified signals does not exceed the second number.

Exemplarily, when there are many amplification levels, the touch state detection unit can obtain more signals amplified to different degrees. In this way, more data needs to be calculated when calculating the overflow rate of each amplified signal. Therefore, in order to reduce the amount of data calculation, the touch state detection unit can first select a certain number of amplified signals from the multi-level amplified signals, that is, ignore a part of the amplified signals first. At present, the selected number is recorded as the first number, and the first number can be set according to the actual situation. Generally, the first number is at least two. When selecting the first number of amplified signals, it can be to select the first number of amplified signals with a continuous amplification level. At this time, the amplification level of the selected amplified signal can be preset. For example, the currently selected continuous amplification level is 1-3. For example, at this time, the touch state detection unit selects the amplified signals corresponding to level 1, level 2 and level 3. Optionally, when among the overflow rates of the first number of amplified signals, the overflow rate exceeding the second number is not within the overflow rate range, it means that the currently selected amplification level is unreasonable, more details are lost or effective amplification is not performed, wherein when more details are lost, the overflow rate exceeding the second number is higher than the overflow rate range, and when effective amplification is not performed, the overflow rate exceeding the second number is lower than the overflow rate range, that is, after selecting the first number of amplified signals, first determine whether the number of amplified signals above the overflow rate range reaches the second number and determine whether the number of amplified signals below the overflow rate range reaches the second number, and then, if both numbers do not reach the second number, select a certain level of amplified signals from the first number of amplified signals, if the number of amplified signals above the overflow rate range exceeds the second number or the number of amplified signals below the overflow rate range exceeds the second number, reselect the amplified signal corresponding to a more reasonable amplification level, wherein the second number can be set according to actual conditions, such as when the first number is 3, the second number is 2. The overflow rate range can be set according to actual requests. Generally speaking, the amplification within the overflow rate range is The signal is a valid amplified signal. Generally speaking, the reselected amplification levels are also continuous. After reselection, continue to determine whether there are more than the second number of overflow rates in the corresponding overflow rates that are outside the preset overflow rate range (higher than the overflow rate or lower than the overflow rate), and then determine whether it is necessary to continue to reselect the amplified signal. For example, after first selecting the amplified signal of levels 1-3, it is determined that two of the three overflow rates are 0, that is, they are not within the overflow rate range. At this time, it is considered that the amplified signal has not been effectively amplified. Therefore, reselect the amplified signal of levels 4-6, and then determine that two of the three overflow rates are within the overflow rate range, and determine that the amplified signal of levels 4-6 is reasonable. Subsequently, the digital amplified signal of levels 4-6 is used for sensor signal detection.

Step 1222: The touch state detection unit selects a first-level amplified signal that is less than an overflow rate threshold according to the overflow rates of the amplified signals of each level.

Exemplarily, the amplified signal currently selected by the touch state detection unit is a digital amplified signal, and the overflow rate of the digital amplified signal is less than the overflow rate threshold. The overflow rate threshold is a priori value, which can be obtained through experience or experimental statistics, such as being set to 10%. When the overflow rate is less than the overflow rate threshold, it means that the loss caused by the overflow during analog-to-digital conversion is small. Therefore, a digital amplified signal with an overflow rate less than the overflow rate threshold can be selected.

In one embodiment, a digital amplified signal that is less than the overflow rate threshold may also be insufficiently amplified. For example, when the overflow rate is 0, although it is less than the overflow rate threshold, it is not actually effectively amplified. This type of digital amplified signal is not conducive to sensing signal detection. Therefore, the touch state detection unit can select a digital amplified signal that is less than the overflow rate threshold and as close to the overflow rate threshold as possible. At this time, step 1222 specifically includes: the touch state detection unit determines an overflow rate that is less than and closest to the overflow rate threshold among the overflow rates, and uses the digital amplified signal corresponding to the determined overflow rate as the currently selected first-level amplified signal, and the digital amplified signal is a signal obtained after analog-to-digital conversion of the corresponding amplified signal.

Optionally, the touch state detection unit sorts the overflow rates of the digitally amplified signals from small to large, and selects the digitally amplified signal corresponding to the overflow rate that is smaller than the overflow rate threshold and closest to the overflow rate threshold.

Afterwards, execute step 123.

Step 123: The touch state detection unit generates a touch state signal when determining that the surface of the display screen receives the sensing signal according to the signal characteristic parameters of the selected amplified signal.

It can be understood that when the surface of the display screen does not receive the sensor signal, the original signal collected by the first sensor only includes the noise signal. When the surface of the display screen receives the sensor signal, the original signal collected by the first sensor includes the superposition of the noise signal and the sensor signal. At this time, compared with only representing the noise signal, after the sensor signal is superimposed, some parameters of the corresponding digital amplified signal will also change significantly. By capturing this part of the change, it can be determined whether the sensor signal is received. In one embodiment, the touch state detection unit can determine whether the surface of the display screen receives the sensor signal by detecting some parameters in the digital amplified signal that change significantly due to the sensor signal. At present, the parameters that change significantly due to the sensor signal are recorded as signal features. Parameters, in one embodiment, the signal characteristic parameters include peak-to-peak value, energy value and time-frequency point energy ratio. In this case, step 123 may include steps 1231-1232:

Step 1231: The touch state detection unit determines the peak-to-peak value, energy value, and time-frequency energy ratio of the selected amplified signal.

The peak-to-peak value can be understood as the difference between the maximum signal value and the minimum signal value in the digital amplified signal. When the surface of the display screen receives the sensor signal, the peak-to-peak value increases sharply, and then when the surface of the display screen does not receive the sensor signal, the peak-to-peak value changes little. The energy value can be understood as the energy of the digital amplified signal. When the surface of the display screen receives the sensor signal, the energy value becomes larger. When the surface of the display screen does not receive the sensor signal, the energy value is the same as the energy value of the background noise (i.e., the noise signal). The time-frequency point energy ratio can be understood as the ratio of the energy in the set frequency band in the digital amplified signal to the energy of the digital amplified signal in the entire frequency band, wherein the set frequency band is a priori value, and the signal points in the set frequency band are highly correlated with the sensor signal. When the surface of the display screen receives the sensor signal, the time-frequency point energy ratio is large, and when the surface of the display screen does not receive the sensor signal, the time-frequency point energy ratio is small. Based on this, the touch state detection unit calculates the peak-to-peak value, energy value and time-frequency point energy ratio of the currently selected digital amplified signal.

Step 1232: When the touch state detection unit determines that the peak-to-peak value is greater than the peak-to-peak value threshold or the energy value is greater than the energy threshold, and the time-frequency point energy ratio is greater than the ratio threshold, it determines that the surface of the display screen receives the sensing signal and generates a touch state signal.

The peak-to-peak value threshold, energy threshold and proportion threshold can be set according to actual conditions, and respectively represent the minimum values of the peak-to-peak value, energy value and energy proportion of the time-frequency point when the surface of the display screen receives the sensor signal. Optionally, the peak-to-peak value threshold, energy threshold and proportion threshold form a detection threshold sequence.

After the touch state detection unit determines the peak-to-peak value, energy value and time-frequency energy ratio of the currently selected digital amplified signal, it determines whether the peak-to-peak value is greater than the peak-to-peak value threshold or the energy value is greater than the energy value threshold, and whether the time-frequency energy ratio is greater than the ratio threshold, wherein the peak-to-peak value and the energy value are in a relationship of or, that is, one of the two exceeds the threshold, and whether the other exceeds the threshold is not considered at present. When the time-frequency energy ratio is greater than the ratio threshold and the peak-to-peak value or energy value is greater than the corresponding threshold, it is determined that the surface of the display screen receives the sensing signal and generates a touch state signal (ie, down). If the time-frequency energy ratio is greater than the threshold but the peak-to-peak value and the energy value are not greater than the corresponding threshold, or the time-frequency energy ratio is not greater than the corresponding threshold, it is determined that the surface of the display screen does not receive the sensing signal.

It should be noted that when the surface of the display screen does not receive the sensor signal, sudden noise will also cause the peak-to-peak value and energy value to change, causing the two to exceed the corresponding thresholds. For example, when the first sensor is a vibration sensor, when the frame of the display screen receives a hard tap, the glass panel of the display screen will also vibrate. At this time, the original signal collected by the vibration sensor will also reflect the current vibration, and the corresponding peak-to-peak value and energy value of the digital amplified signal may also exceed the corresponding threshold. Therefore, using only the peak-to-peak value and energy value to determine whether the surface of the display screen receives the sensor signal is not accurate. For another example, when the first sensor is a vibration sensor, when the interactive tablet plays music, the original signal collected by the vibration sensor will also reflect the current vibration, and the corresponding digital amplified signal will also exceed the corresponding threshold. The time-frequency energy ratio of the digital amplified signal may also exceed the ratio threshold. Therefore, the accuracy of judging whether the surface of the display screen receives the sensor signal by only using the time-frequency energy ratio is not high. Based on this, the peak-to-peak value or energy value and the time-frequency energy ratio are used in the embodiment to comprehensively judge whether the display screen receives the sensor signal, which can ensure the accuracy of the sensor signal detection.

In one embodiment, when the first sensor collects the original signal, due to the influence of factors such as the circuit in the interactive flat panel and environmental noise, there is a noise signal in the original signal, and the noise signal is not conducive to the detection of the sensor signal. Therefore, after selecting a certain level of digital amplification signal, the sensor signal and the noise signal can be separated first. This process can also be considered as a process of filtering out the noise signal.

Optionally, when filtering out noise signals, an autocorrelation or adaptive method may be used. In this case, the touch state detection unit determines that the surface of the display screen receives the sensing signal according to the signal characteristic parameters of the selected amplified signal and generates the touch state signal before: the touch state detection unit performs an autocorrelation operation on the selected amplified signal to obtain an autocorrelation calculation result; when the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold, the touch state detection unit performs an operation of determining that the display screen receives the sensing signal according to the signal characteristic parameters of the selected amplified signal and generates the touch state signal.

Currently, the selected amplified signal refers to a digital amplified signal. Exemplarily, according to the characteristics of the noise signal, the stationary noise signal can be filtered out by autocorrelation or adaptive means, wherein stationary noise and non-stationary noise are relatively common noises.

The noise signal (also referred to as noise) and the sensing signal are unrelated random signals, so the result of the autocorrelation calculation is very small, while the sensing signal is not a random signal, but a related signal (both related to stress or vibration during touch), so the result of the autocorrelation calculation is very large. At this time, the autocorrelation calculation result of the digitized amplified signal can be used to determine whether the digitized amplified signal is related to the sensing signal.

Currently, the digital amplified signal used is recorded as s[n], n = 0, 1, ..., N, N is the total number of signal points of the digital amplified signal. s[n] represents the signal value of the nth signal point. The noise signal in the digital amplified signal is recorded as w[n], and the external force signal in the digital amplified signal is recorded as a[n]. At this time, s[n] can be expressed as:
s[n]＝a[n]+w[n]，n＝0、1、……、N

The digital amplified signal at time _n1 (which can be understood as the digital amplified signal selected next time) can be expressed as:
s[n+n ₁ ]＝a[n+n ₁ ]+w[n+n ₁ ]，n＝0、1、……、N

Wherein, s[n+n ₁ ] represents the signal value of the nth signal point at time n _1. a[n+n ₁ ] represents the signal value of the sensing signal at the nth signal point at time n _1. w[n+n ₁ ] represents the signal value of the noise signal at the nth signal point at time n ₁ .

When the autocorrelation operation is performed on the digital amplified signal at time n ₁ , the autocorrelation calculation process can be expressed as:

Where R[n] represents the autocorrelation calculation result. Since the noise signal and the sensor signal are uncorrelated, and The values of are approximately equal to zero. At this time, R[n] can be expressed as:

It can be understood that since the autocorrelation calculation result of the noise signal is very small, can be ignored. At this time, R[n] can reflect the autocorrelation calculation result of the sensing signal.

After the touch state detection unit obtains the autocorrelation calculation result, it determines the maximum value of the autocorrelation calculation result, that is, selects the maximum value from the respective correlation calculation results corresponding to n=0, 1, ..., N, and then compares the maximum value with the autocorrelation threshold. Among them, the autocorrelation threshold can be obtained through experimental statistics or derived according to the constant false alarm rate (CFAR). Generally speaking, when the display screen receives the sensor signal, the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold. Therefore, when the touch state detection unit determines that the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold, it can be preliminarily considered that the surface of the display screen receives the sensor signal, that is, the digital amplified signal may be related to the sensor signal, and therefore, it can be performed to determine that the surface of the display screen receives the sensor signal according to the signal characteristic parameters of the selected amplified signal, and generate the touch state signal (that is, judging whether the display screen receives the sensor signal according to the peak-to-peak value, energy value and time-frequency point energy ratio, and receiving the sensor signal, that is, generating the touch state signal). Otherwise, it is determined that the digital amplified signal only contains the noise signal, so the entire digital amplified signal can be filtered out.

In one embodiment, after determining that the surface of the display screen may have received the sensor signal based on the autocorrelation calculation result, the noise signal in the digitized amplified signal can also be filtered out to reduce the interference of the noise signal when determining whether the sensor signal is received based on the signal characteristic parameters later. At this time, when the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold, the touch state detection unit performs the operation of generating a second state signal based on the sensor signal when determining that the surface of the display screen has received the sensor signal based on the selected amplified signal, which may include: when the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold, the touch state detection unit detects a pulse-shaped signal segment in the selected amplified signal; the touch state detection unit performs frequency domain transformation on the signal segment to obtain a frequency domain signal segment; the touch state detection unit selects a sub-frequency domain signal segment within a preset frequency band in the frequency domain signal segment; the touch state detection unit performs time domain transformation on the sub-frequency domain signal segment to obtain an amplified signal with non-stationary noise filtered out, and performs the operation of determining that the surface of the display screen has received the sensor signal based on the signal characteristic parameters of the selected amplified signal. When the sensing signal is generated, a second state signal is generated according to the sensing signal.

Exemplarily, the noise signal currently filtered out is a non-stationary noise signal. When filtering out the noise signal, time-frequency analysis can be used, that is, analyzing the time domain characteristics and frequency domain characteristics of the digital amplified signal. Specifically, for the non-stationary noise signal in the digital amplified signal, it is significantly different from the sensing signal in both the time domain and the frequency domain. The sensing signal is concentrated in the set frequency band in the frequency domain, where the set frequency band is an empirical value, while the non-stationary noise signal may be distributed in the full frequency (that is, all frequency bands of the digital amplified signal in the frequency domain). The sensing signal is generally in the form of a pulse in the time domain (due to stress or vibration), and the non-stationary noise audio is not in the form of a pulse in the time domain and appears continuously. It will not only appear when the touch object touches the surface of the display screen and disappear when the touch leaves the surface of the display screen. Based on the above distinction, the touch state detection unit can filter out the non-stationary noise signal in the digital amplified signal by means of time-frequency analysis.

Exemplarily, during time-frequency analysis, the touch state detection unit first detects the digital amplified signal in the time domain to extract a reasonable signal segment (i.e., a segment of the digital amplified signal). When detecting and extracting, it can be to detect the pulse signal in the digital amplified signal and extract it to obtain the signal segment. At this time, it can be considered that the noise signal detected in the time domain is filtered out. Among them, the pulse signal can also be understood as a pulse signal. Optionally, the touch state detection unit can detect the pulse signal by calculating the signal-to-noise ratio (SNR), the ringing rate (ringing count rate), the short-time energy change value, etc., wherein the ringing rate can be determined by the ratio of the maximum amplitude of the oscillation waveform to the pulse amplitude or the number of oscillation cycles, and the short-time energy change value can be obtained by sliding the window to calculate the energy of the oscillation waveform. For example, a signal with a signal-to-noise ratio higher than a preset signal-to-noise ratio can be considered as a pulse signal, or a signal with a ringing rate higher than a preset ringing rate can be considered as a pulse signal, or a pulse signal is considered to appear when the short-time energy change value is greater than a preset threshold (i.e., a preset short-time energy change value). It can be understood that if the touch state detection unit does not detect a pulse signal in the digitized amplified signal, it can be determined that the digitized amplified signal is irrelevant to the sensing signal, and therefore the entire digitized amplified signal can be filtered out.

After selecting the signal segment in the form of a pulse, the touch state detection unit performs a frequency domain transformation on the signal segment (i.e., converts it into a signal in the frequency domain) to obtain a signal segment in the frequency domain, which is currently recorded as a frequency domain signal segment. The technical means used for frequency domain transformation are not currently limited. Currently, the frequency values at both ends of the preset frequency band in the sensor signal set are recorded as f1 and f2, respectively, and f1 and f2 are empirical values. Exemplarily, after the touch state detection unit obtains the frequency domain signal segment, it obtains the component between f1 and f2, that is, obtains the frequency domain signal segment in the preset frequency band. Currently, the obtained frequency domain signal segment in the preset frequency band is recorded as a sub-frequency domain signal segment, wherein the sub-frequency domain signal segment is highly correlated with the sensor signal. After that, the sub-frequency domain signal segment is transformed in the time domain (i.e., converted into a signal in the time domain) to obtain a signal in the time domain, which can be considered as an amplified signal (currently a digitized amplified signal) that filters out non-stationary noise. In one embodiment, the touch state detection unit filters out non-stationary noise signals (including interference signals) through a time-frequency domain filter. The type of time-frequency domain filter is not currently limited. For example, the phase signal of the digital amplified signal is not involved in the time-frequency analysis. Therefore, an IIR filter can be used as the time-frequency domain filter. To achieve an efficient filtering effect. Among them, the IIR filter is also called the IIR digital filter, which is a more commonly used filter. At this time, the touch state detection unit also includes a time-frequency domain filter, and the digital amplified signal is input into the time-frequency domain filter to obtain a digital amplified signal that filters out non-stationary noise.

In one embodiment, when the surface of the display screen receives a sensing signal, the energy value of the sub-frequency domain signal segment within the preset frequency band is relatively large. Therefore, it is also possible to determine whether the digital amplified signal contains the sensing signal in combination with the energy value. At this time, the touch state detection unit performs a time domain transformation on the sub-frequency domain signal segment to obtain an amplified signal that filters out non-stationary noise, including: when the touch state detection unit determines that the energy value of the sub-frequency domain signal segment is greater than an energy threshold, the sub-frequency domain signal segment is transformed in the time domain to obtain an amplified signal that filters out non-stationary noise.

Exemplarily, after the touch state detection unit extracts the sub-frequency domain signal segment within the preset frequency band, it calculates the energy value of the sub-frequency domain signal segment. If the energy value is greater than a preset energy threshold (which can be set based on experience), it is determined that the sub-frequency domain signal segment is related to the sensing signal. At this time, the sub-frequency domain signal segment can be transformed in the time domain to obtain a digital amplified signal that filters out non-stationary noise.

It should be noted that the touch state detection unit can filter out noise by autocorrelation operation and time-frequency analysis. At this time, the touch state detection unit performs an autocorrelation operation on the selected digital amplified signal. After that, if the maximum value of the autocorrelation calculation result obtained by the autocorrelation operation is greater than the autocorrelation threshold, a time-frequency analysis is performed. During the time-frequency analysis, the energy value of the sub-frequency domain signal segment is greater than the energy threshold, and it is determined that a digital amplified signal related to the sensing signal (a signal in the form of a pulse within the set frequency band) is obtained. At this time, the noise signal is greatly weakened. After that, the touch state detection unit further judges the digital amplified signal with the noise signal removed to determine whether the display screen receives the sensing signal. If the maximum value of the autocorrelation calculation result is not greater than the autocorrelation threshold, the pulse signal segment is not selected, or the energy value of the sub-frequency domain signal segment is not greater than the energy threshold, the digital amplified signal is determined to be a noise signal, and therefore, no subsequent processing is performed.

Step 130: The processing unit generates an occlusion state signal according to the occlusion data signal, and determines whether the display screen receives a touch operation according to the occlusion state signal and the touch state signal.

Exemplarily, after receiving the occlusion data signal, the processing unit analyzes the occlusion data signal to determine whether there is currently blocked light based on the occlusion data signal. If there is blocked light, it is determined that there is a touch object causing occlusion, and an occlusion status signal is generated, wherein the occlusion status signal is used to indicate that light is currently blocked, that is, there is a possibility that the touch object is in contact with the surface of the display screen. In one embodiment, the occlusion status signal includes two types, down and move, where down indicates that the touch object has fallen and just touched the surface of the display screen, and move indicates that the touch object has touched the surface of the display screen and is moving on the surface. It can be understood that the signal corresponding to the occlusion status signal can be recorded as a non-blocking status signal, which is used to indicate that no light is blocked, and the non-blocking status signal can be recorded as up. Taking the writing scene as an example, in a writing process, the processing unit generates at least down, move, move, ..., up.

When the touch object just touches the display screen surface, that is, from up to down (from lifting to putting down the pen), the amount of blocked light will change from 0 to a non-zero value. Therefore, when the processing unit generates up at the previous moment and determines that blocking occurs according to the touch data signal at the current moment, it generates down. When the processing unit generates down or move at the previous moment and determines that blocking occurs according to the touch data signal at the current moment, it generates move. When the processing unit determines that no blocking occurs according to the touch data signal at the current moment, it generates up. Optionally, when the touch object just touches the surface, the change amount of blocked light will change significantly, and when the touch object moves on the display screen surface, that is, from down to move (from pen down to move) or from move to move (continuous movement), the touch object continues to block the light, at this time, the change amount of blocked light is small, and the change amount is less than the change amount from up to down, and when the touch object leaves the display screen surface, that is, from down to up or from move to up, the change amount of blocked light will also change significantly, that is, from a non-zero value to zero, therefore, when the processing unit generates down, move and up, it can be combined with the change amount of blocked light to assist in verifying whether the generated down, move and up are accurate. For example, when generating down, the processing unit determines whether the change amount of the current blocked light is greater than a quantity threshold (the quantity threshold is the minimum value of the change amount of the blocked light when the touch object falls and lifts up), if it is greater than the quantity threshold, then generate down, otherwise, it is considered to be a false blockage, and therefore, no response is made. It should be noted that the down and up signals generated by the processing unit have different specific meanings from the down and up signals sent by the touch status detection unit. In the data structure of the processing unit, they belong to a byte in different data formats and can be effectively distinguished.

Optionally, when the processing unit generates an occlusion state signal (down or move), the occlusion position can also be determined according to the occlusion data signal. Currently, the occlusion position is determined by an existing determination method. The occlusion position can be represented by a two-dimensional coordinate in a two-dimensional coordinate system, which is a coordinate system used by the optical network.

When the processing unit generates an occlusion status signal (down or move), it can be clearly determined that multiple light rays on the surface of the display screen are blocked, but it cannot be determined whether the blocking object is hovering above the screen of the display screen or has touched the display screen. Therefore, the occlusion status signal is only a necessary but not sufficient condition for determining a touch operation. At this time, the processing unit also needs to determine whether a touch operation is received in combination with the detection result reported by the touch status detection unit (touch status signal or non-touch status signal).

Exemplarily, if the processing unit receives a touch status signal when generating an occlusion status signal, it determines that the light is blocked and the surface of the display screen receives the sensing signal, and therefore, it can be determined that the display screen receives a touch operation. Optionally, if the occlusion status signal is down and the touch status signal is down, the processing unit determines that the current touch object has just touched the surface of the display screen; if the occlusion status signal is move and the touch status signal is down, the processing unit determines that the current touch object has already touched the surface of the display screen and moved. At this time, the processing unit can determine the occlusion position as the touch position of the touch operation. Afterwards, the processing unit responds to the touch operation based on the touch position. For example, in a writing scenario, when the processing unit responds to a writing operation, when the processing unit determines that the touch operation is a writing operation (such as when the touch position changes), the processing unit changes the state of the display screen. The state of the display screen is set to the writing state, and the corresponding writing track is displayed according to the touch position. When the touch operation is other touch operations other than writing (such as the touch position has not changed), the processing unit sets the state of the display screen to the touch state, and determines the display content targeted by the touch operation according to the touch position, and then makes a corresponding response. For another example, in a writing scenario, an application with a writing function responds to the writing operation, and the application is currently running and displays the corresponding interface on the display screen. At this time, the processing unit sends the received touch operation and touch position to the application, and the application responds.

It should be noted that the execution timing of step 110 and step 120 is not clearly defined, and the optical detection unit and the touch state detection unit both work in real time so that the processing unit can determine in real time whether a touch operation is detected. In addition, the processing unit can be one, or two or more. When there are two processing units, one of them can be used to calculate the occlusion state signal, and the other can be used to determine whether a touch operation is received by combining the occlusion state signal and the detection result (touch state signal or non-touch state signal) reported by the touch state detection unit.

In the above, the optical detection unit detects the reception of the light covering the surface of the display screen and reports the occlusion data signal to the processing unit, the touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor set on the back of the display screen in real time, and determines based on the multi-stage amplified signal that the surface of the display screen receives the sensing signal, reports the touch state signal to the processing unit, and the processing unit generates an occlusion state signal according to the occlusion data signal, and determines that the display screen receives the touch operation according to the occlusion state signal and the touch state signal. The technical means solves the technical problem of easy misdetection when using optical detection means to detect touch operations in related technologies. On the basis of optical detection, a first sensor is added, wherein the first sensor is a mechanical sensor or a vibration sensor set on the side of the display screen away from the user to detect the force generated when the display screen is touched, overcomes the misdetection problem caused by a certain distance between the light and the surface of the display screen, and improves the detection accuracy. In addition, by multi-stage amplification of the original signal collected by the first sensor, it can be ensured that the signal changes caused by the touch operation contacting the display screen with different forces and different speeds can be amplified to a reasonable signal-to-noise ratio, ensuring the accuracy of the touch state signal, thereby further improving the detection accuracy. Moreover, by judging the validity through the overflow rate, it is possible to select an amplified signal with a reasonable amplification level, ensuring that the signal is reasonably amplified while retaining the characteristics of the signal to the greatest extent. Moreover, by filtering out noise signals through multi-dimensional noise reduction (autocorrelation and time-frequency analysis), the influence of noise signals on the detection results can be reduced, and the detection accuracy can be improved. Moreover, the touch state detection unit determines whether the surface of the display screen receives the sensing signal through multi-dimensional fusion (i.e., through the peak-to-peak value, energy value and energy ratio of the time-frequency point), and then determines whether to generate a touch state signal, which can ensure the accuracy of the sensing signal detection and thus improve the detection accuracy of the touch operation.

In one embodiment of the present application, there is a situation where the processing unit only receives a touch status signal but does not generate an occlusion status signal (i.e., generates a non-occlusion status signal). At this time, the touch detection method also includes: when the processing unit receives the touch status signal and generates a non-occlusion status signal based on the occlusion data signal, determining that the display screen has not received a touch operation.

It is understandable that the touch operation will inevitably block the light. If the processing unit determines that the light is not currently blocked according to the blocking data signal If there is no light, that is, no touching object is close to or in contact with the surface of the display screen, a non-blocking state signal (i.e., up) is generated. At this time, regardless of whether the touch state signal is received, the processing unit considers that no touch operation is detected. At this time, if the processing unit receives the touch state signal but does not generate a blocking state signal (i.e., generates a non-blocking state signal), it can be considered that the sensing signal detected by the touch state signal belongs to noise interference, and therefore, no processing is performed.

As described above, when the processing unit does not generate a non-occluded state signal, it is considered that no touch operation is detected regardless of whether a touch state signal is received, thereby avoiding the influence of the touch operation detection result when the touch state signal is erroneously generated due to noise interference, and ensuring the detection accuracy of the touch operation.

FIG2 is a flow chart of a touch detection method provided by an embodiment of the present application. The touch detection method is based on the above embodiment, and adds a description of the scenario where there is only an occlusion state signal but no touch state signal. Referring to FIG2, the touch detection method includes:

Step 210 : The optical detection unit determines the shielding data signal according to the light signal received by the light receiver and reports the shielding data signal to the processing unit. Then, step 230 is executed.

Step 220: The touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time, and generates a non-touch state signal when it is determined based on the multi-stage amplified signal that the surface of the display screen has not received the sensing signal, and reports the non-touch state signal to the processing unit. Execute step 230.

The touch state detection unit continuously determines whether the surface of the display screen receives the sensing signal, and when it is determined that the sensing signal is received, generates a touch state signal (ie, down) and reports it to the processing unit, and when it is determined that the sensing signal is not received, generates a non-touch state signal (ie, up) and reports it to the processing unit. That is, the touch state detection unit continuously reports the current detection result of the sensing signal to the processing unit.

Exemplarily, the touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time to obtain a multi-stage amplified signal, and then selects a first-stage amplified signal from the multi-stage amplified signal, and generates a non-touch state signal when it is determined that the display screen does not receive the sensor signal according to the selected amplified signal. Among them, the touch state detection unit can select a first-stage amplified signal according to the overflow rate of each stage of the amplified signal. This process can refer to the relevant description of step 122 in the aforementioned embodiment. The touch state detection unit determines the peak-to-peak value, energy value and time-frequency point energy ratio of the selected amplified signal. If the time-frequency point energy ratio is not greater than the ratio threshold, or the peak-to-peak value and energy value are both less than the corresponding threshold, it is determined that the display screen does not receive the sensor signal, and a non-touch state signal (ie up) is generated. Optionally, when the touch state detection unit filters out noise, it first performs a sub-correlation operation on the selected amplified signal, and the maximum value of the autocorrelation calculation result is not greater than the autocorrelation threshold, then it is determined that the surface of the display screen does not receive the sensor signal, and a non-touch state signal is generated. If the touch state detection unit does not select a pulse-shaped signal segment in the selected amplified signal, it also determines that the surface of the display screen does not receive the sensor signal, and generates a non-touch state signal. The touch state detection unit determines that the energy value of the selected pulse signal segment within the preset frequency range is not greater than the energy threshold When the touch signal is not received, it is determined that the surface of the display screen does not receive the sensing signal and a non-touch state signal is generated.

Step 230, when the processing unit generates an occlusion status signal according to the occlusion data signal at the current moment and receives a non-touch status signal, it determines the real-time quantity value of the blocked light at the current moment according to the occlusion data signal, and determines the first quantity change value of the blocked light at the current moment according to the real-time quantity value; if the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, it is determined that the display screen receives a touch operation and the second quantity threshold is greater than the first quantity threshold.

For the processing unit, there are four situations when it detects touch operations: 1. Generate an occlusion state signal and receive a touch state signal; 1. Generate a non-occlusion state signal and receive a touch state signal; 2. Generate a non-occlusion state signal and receive a non-touch state signal; 4. Generate an occlusion state signal and receive a non-touch state signal. The response methods for the first three situations have been described in the previous embodiments. Currently, the fourth situation is described, and the detected touch operation is a moving operation, which means that the touch object needs to move on the surface of the display screen.

Currently, the reason why the processing unit generates an occlusion status signal based on the occlusion data signal and receives a non-touch status signal may be: the touch object blocks the light but does not touch the display screen (such as the touch object hovers above the display screen); or the touch force is too light so that the touch status detection unit fails to detect the sensor signal. For example, when the force of the touch object touching the display screen becomes lighter or the touch speed becomes smaller, the amplitude of the change in the original signal collected by the first sensor is very small, and the sensor signal is easily submerged in the noise signal. At this time, the touch status detection unit is easily misidentified as the surface of the display screen does not receive the sensor signal and generates a non-touch status signal. Therefore, the processing unit needs to further determine whether a touch operation is currently received.

Currently, when the touch object is hovering, the touch object moves very little, and the number of blocked light rays changes very little. However, when the touch object contacts the display screen and moves, the number of blocked light rays changes greatly. Therefore, it is possible to determine whether a touch operation is received by the number of blocked light rays. Specifically, when the processing unit generates an occlusion state signal, it also counts the number of blocked light rays based on the occlusion data signal. In an embodiment, the number of blocked light rays counted at the current moment is recorded as the real-time number value of the blocked light rays. It can be understood that the processing unit can count the real-time number value in real time, and when there is no occlusion (i.e., when a non-occlusion state signal is generated), the real-time number value is zero. Exemplarily, after counting the real-time number value, the absolute value of the difference between the real-time number value at the current moment and the real-time number value at the previous moment is calculated. The difference can reflect the degree of increase or decrease in the number of blocked light rays at the current moment. In an embodiment, the absolute value of the difference is recorded as the first quantity change value. Afterwards, the first quantity change value is compared with the first quantity threshold and the second quantity threshold, wherein the first quantity threshold and the second quantity threshold are quantity thresholds set in combination with actual conditions, the first quantity threshold is less than the second quantity threshold, the first quantity threshold can be understood as the minimum value of the quantity change (absolute value) of the blocked light when the touch object contacts the display surface and moves, and the second quantity threshold can be understood as the minimum value of the quantity change (absolute value) of the blocked light when the touch object just contacts the display surface or just leaves the display surface. When the processing unit generates an occlusion state signal and receives a non-touch state signal, if the first quantity change value is greater than or equal to the first quantity threshold, it indicates that the change in the quantity of the currently blocked light meets the change in quantity when the touch object contacts and moves on the surface of the display screen, that is, the touch object has moved on the surface of the display screen, and the first quantity change value is less than or equal to the second quantity threshold, then it indicates that the touch object has not left the surface of the display screen. Therefore, when the first quantity change value is greater than or equal to the first quantity threshold and less than the second quantity threshold, the processing unit believes that the touch object contacts the surface of the display screen, that is, determines that the touch operation is received.

In one embodiment, after the processing unit determines the real-time quantity value of the blocked light at the current moment according to the occlusion data signal, and determines the first quantity change value of the blocked light at the current moment according to the real-time quantity value, it may also include: if the first quantity change value is less than the first quantity threshold, the processing unit determines that the display screen has not received a touch operation.

Exemplarily, after comparing the first quantity change value with the first quantity threshold and the second quantity threshold, if the first quantity change value is less than the first quantity threshold, it means that the quantity change of the currently blocked light is not sufficient to meet the quantity change when the touch object contacts and moves on the surface of the display screen (the touch object moves very little when hovering, so the first quantity change value is very small). Therefore, the processing unit believes that the touch object has not touched the surface of the display screen, that is, the touch operation has not been received, and gives up responding.

In one embodiment, after the processing unit determines the real-time quantity value of the blocked light at the current moment according to the occlusion data signal, and determines the first quantity change value of the blocked light at the current moment according to the real-time quantity value, it also includes: if the first quantity change value is greater than the second quantity threshold, the processing unit continues to calculate the second quantity change value of the blocked light at the next moment; if the second quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, the processing unit determines that the display screen has received a touch operation; if the second quantity change value is less than the first quantity threshold, the processing unit determines that the display screen has not received a touch operation.

Exemplarily, after comparing the first quantity change value with the first quantity threshold and the second quantity threshold, if the first quantity change value is greater than the second quantity threshold, it means that the current touch object has just touched the surface of the display screen, and therefore, it can be considered that the touch operation is received. Optionally, when the touch object just hovers on the surface of the display screen, the change in the amount of blocked light may also be greater than the second quantity threshold, such as when the touch object is very close to the surface of the display screen, the amount of light blocked by it is equal to or close to the amount of light blocked when the touch object touches the surface of the display screen, and therefore, the processing unit needs to further determine whether the touch object touches the display screen. Among them, when further judging, the processing unit combines the occlusion data signal of the next moment to count the number of blocked light rays at the next moment, and then calculates the absolute value of the difference between the number of blocked light rays at the next moment and the number of blocked light rays at the moment before the next moment (here is the current moment). Currently, for the sake of easy distinction, the absolute value of the difference obtained based on the real-time number value of the blocked light rays at the next moment and the real-time number value of the blocked light rays at the current moment is recorded as the second quantity change value. Then, the second quantity change value is compared with the first quantity threshold and the second quantity threshold respectively. If it is greater than or equal to the first quantity threshold and less than the second quantity threshold, it means that the touch object has moved on the surface of the display screen. Therefore, the processing unit believes that a touch operation has been received. It can be understood that determining that a touch operation has been received is the result obtained by the processing unit at the next moment. For when For the previous moment, the processing unit will not generate a detection result of the touch operation temporarily. If the second quantity change value is less than the first quantity threshold, it means that the touch object is hovering above the surface of the display screen. Therefore, the processing unit determines that no touch operation is received. If the second quantity change value is greater than the second quantity threshold, it means that the light blocked at the current moment may be due to false blocking caused by other factors (non-touch operation). Therefore, the processing unit determines that no touch operation is received. It should be noted that when the touch object leaves the surface of the display screen, the first quantity change value will also be greater than the second quantity threshold. At this time, it can be further determined whether the real-time quantity value of the blocked light at the next moment is zero. If it is zero, it is determined that the touch object has left the display screen. Therefore, the method can also accurately identify the situation where the touch object leaves the display screen, that is, it can identify the situation where the pen is lifted during the writing process.

In one embodiment, there is a situation where the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, but the touch object still does not touch the display screen, such as the touch object hovers on the surface of the display screen and moves. At this time, in order to ensure the detection accuracy of the touch operation, the processing unit can make further judgments. Accordingly, after the touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time and obtains the multi-stage amplified signal, it also includes: the touch state detection unit selects a third number of amplified signals from the multi-stage amplified signal, the third number is at least two, and the third number of amplified signals are amplified signals with continuous amplification levels. If the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, the processing unit determines that the display screen has received a touch operation, which may include: if the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, the processing unit instructs the touch state detection unit to reselect the third number of amplified signals and select a first-level amplified signal from the third number of amplified signals, determines that the surface of the display screen has received the sensing signal according to the selected amplified signal, generates a touch state signal, reports the touch state signal to the processing unit, and the amplification level of the reselected amplified signal is greater than the amplification level of the amplified signal before reselection; the processing unit determines that the display screen has received a touch operation according to the occlusion state signal and the touch state signal.

Exemplarily, during further judgment, in order to ensure that the touch operation is accurately identified, the currently used amplification level can be changed to ensure that the sensing signal is accurately amplified and detected. Specifically, the process of the touch state detection unit selecting the third number of amplified signals from the multi-level amplified signals can refer to the process of the touch state detection unit selecting the first number of amplified signals from the multi-level amplified signals. The third number can be set according to actual conditions, and the third number can be equal to the first number. When the processing unit determines that the first number change value is greater than or equal to the first number threshold and less than or equal to the second number threshold, it instructs the touch state detection unit to reselect the third number of amplified signals from all amplified signals, wherein the reselection process can refer to the relevant description of reselecting the first number of amplified signals in step 120. The amplification level of the reselected amplified signal is generally greater than or partially greater than the amplification level of the previously selected amplified signal, that is, the amplification factor is increased, so that the sensing signal is captured and amplified. Afterwards, the touch state detection unit selects a first-level amplified signal again from each reselected amplified signal, and selects to determine whether the surface of the display screen receives the sensing signal based on the selected amplified signal, and when it is determined that the display screen receives the sensing signal, generates a touch state signal and reports it to the processing unit. At this time, the processing unit can Determine whether a touch operation is received based on the touch state signal and the occlusion state signal. When the touch state detection unit determines that the surface of the display screen does not receive the sensing signal, it generates a non-touch state signal and reports it to the processing unit. At this time, the processing unit can continue to determine whether a touch operation is received based on the non-touch state signal and the occlusion state signal. It is understandable that if the touch state detection unit has reselected all the amplified signals but still has not detected the sensing signal, the processing unit determines that the touch operation is not received.

Optionally, the process of reselecting the amplification level can also be executed when an occlusion state signal is generated but a non-touch state signal is received, that is, the amplified signal corresponding to the different amplification levels is first reselected, and it is determined whether the sensor signal is detected. If all the amplified signals have been reselected but the sensor signal is still not detected, the processing unit calculates the first quantity change value, and determines whether a touch operation is received in combination with the first quantity threshold and the second quantity threshold.

It should be noted that when the touch object leaves the display screen, the touch state detection unit cannot detect the sensing signal. At this time, the touch state detection unit can further determine the energy value of the selected amplified signal, and then compare the currently determined energy value with the energy value of the amplified signal selected at the previous moment to determine whether the energy attenuation of the amplified signal conforms to the attenuation law when the touch object leaves the display screen surface. It can be understood that when the touch object leaves the display screen, the energy of the original signal collected by the first sensor will be greatly attenuated. If the energy attenuation of the amplified signal conforms to the attenuation law when the touch object leaves the display screen, the touch state detection unit generates a non-touch state signal and notifies the processing unit that the energy attenuation of the amplified signal conforms to the attenuation law when the touch object leaves the display screen. If the energy attenuation of the amplified signal does not conform to the attenuation law when the touch object leaves the display screen, it may be that the touch object touches at a slow speed (i.e., moves slowly) or the touch object touches the display screen surface with a very light force. At this time, the touch state detection unit does not generate a touch state signal and notifies the processing unit that the energy attenuation of the amplified signal does not conform to the attenuation law when the touch object leaves the display screen. When the processing unit receives a non-touch state signal and generates an occlusion state signal, if the energy attenuation of the amplified signal sent by the touch state detection unit conforms to the attenuation law when the touch object leaves the display screen, the processing unit determines that no touch operation is received; if the energy attenuation of the amplified signal sent by the touch state detection unit does not conform to the attenuation law when the touch object leaves the display screen, the processing unit calculates a first quantity change value, and determines whether a touch operation is received in combination with the first quantity change value.

As described above, the optical detection unit generates an occlusion data signal according to the received light signal and reports the occlusion data signal to the processing unit. When the touch state detection unit detects that the display screen has not received the sensor signal according to the first sensor set on the side facing away from the glass panel of the display screen, it reports a non-touch state signal to the processing unit. When the processing unit generates an occlusion state signal according to the occlusion data signal and receives the non-touch state signal, the technical means for determining whether the display screen has received a touch operation is combined with the change in the amount of blocked light. This can achieve detection correction. When the force of touching the display screen is light, the touch operation can be further detected by combining the change speed of the touch position or changing the amplification level, thereby improving the detection accuracy of the touch operation. In addition, when the change in the amount of blocked light meets the blocked light when the touch object moves on the surface of the display screen. When the number of changes occurs, it is possible to further determine whether the sensing signal is detected by reselecting the amplification level of the signal, so as to further improve the detection accuracy of the touch operation, and accurately identify the situation where the touched object leaves the touch display screen, thereby improving the detection accuracy of the touch device state during the writing process.

In one embodiment of the present application, there is a short pause (i.e., the touch object is briefly still) from the time the touch object first touches the display screen to the time the control (e.g., movement) is performed. For example, when the touch object writes on the display screen, there is a short pause from the time the pen is put down to the time the writing begins. The short pause will reduce the stress received by the display screen or the vibration generated (i.e., the sensing signal becomes smaller), thereby causing the touch state detection unit to fail to detect the sensing signal and generate a non-touch state signal. At this time, the processing unit will generate an occlusion state signal and receive a non-touch state signal. Furthermore, during the pause period, the first quantity change value will be less than the first quantity threshold, so the processing unit will consider that no touch operation is received. In this case, in order to avoid the influence of the pause period on the touch operation, the touch state detection unit needs to perform additional processing for the pause period when the touch object just contacts the display screen. In one embodiment, when the touch state detection unit determines that the surface of the display screen receives the sensor signal based on the multi-level amplified signal, the touch state signal is generated, and the touch state signal is reported to the processing unit, including: when the touch state detection unit determines that the surface of the display screen receives the sensor signal at the current moment and does not receive the sensor signal at the previous moment based on the multi-level amplified signal, the touch starts and generates the touch state signal, and reports the touch state signal to the processing unit; the touch state detection unit enters a static phase, and the touch state detection unit stops detecting the sensor signal in the static phase and stops reporting the detection result to the processing unit; when the touch state detection unit determines that the duration of the static phase reaches the first duration, the static phase ends, and continues to perform multi-level amplification according to the original signal collected in real time by the first sensor, and when the touch state detection unit determines that the surface of the display screen receives the sensor signal based on the multi-level amplified signal, the touch state signal is generated, and the touch state signal is reported to the processing unit. Correspondingly, the touch detection method further includes: in the static stage, when the processing unit generates an occlusion state signal according to the occlusion data signal and does not receive a detection result reported by the touch state detection unit, determining that the display screen receives a touch operation.

Exemplarily, when the touch state detection unit determines that the surface of the display screen receives a sensing signal at the current moment, it can determine whether the sensing signal is a sensing signal when the touch object just touches the display screen, or a sensing signal when the touch object moves on the display screen. It can be understood that when the touch state detection unit detects a sensing signal at the current moment and does not detect a sensing signal at the previous moment, it can be considered that the touch object did not touch the surface of the display screen at the previous moment, and the touch object touches the surface of the display screen at the current moment, that is, the touch object just touches the display screen at the current moment (that is, the touch starts), at this time, the touch state detection unit generates a touch state signal and reports it to the processing unit, so that the processing unit determines whether a touch operation is detected, and the touch state detection unit enters a static stage.

It should be noted that when the touch object just touches the display screen, the force is relatively large, the sensor signal is relatively obvious, and it is easy to be detected by the touch state detection unit. Therefore, the touch state detection unit can also detect whether the current sensor signal is a sensor signal when the touch object just touches the display screen, or a sensor signal when the touch object moves on the display screen by detecting the energy value of the amplified signal, the energy proportion of the time-frequency point, etc. For example, the energy value when the touch object just touches the display screen is greater than the energy value when it moves, or the touch object The energy proportion of the time-frequency point when just touching the display screen is greater than that of the time-frequency point when moving.

After the touch state detection unit enters the static stage, it will no longer detect the sensing signal, and will not generate the touch state signal and the non-touch state signal. The processing unit will not receive the touch state signal and the non-touch state signal. At this time, the processing unit can also determine that the touch state detection unit has entered the static stage. Optionally, when the processing unit does not receive the detection result reported by the touch state detection unit, if the blocking state signal is generated, it is determined that the touch object continues to block the light after contacting the surface of the display screen, and therefore, it is determined that the touch operation is detected. If the blocking state signal is not generated, it is determined that the touch object does not continue to block the light after contacting the surface of the display screen (such as during the click operation, the touch object leaves the display screen soon after the pen is put down). Therefore, when the processing unit does not generate the blocking state signal, it is determined that the touch operation is not detected. It can be seen that when the processing unit does not receive any signal reported by the touch state detection unit, the detection of the touch operation is realized by relying on the blocking data signal reported by the optical detection unit.

Exemplarily, after the touch state detection unit enters the static phase, it starts timing to determine the duration of the static phase, and then ends the static phase when the duration reaches the first duration. The first duration is the duration of a short pause when the touch object contacts the display screen, which can be an empirical value. When the duration reaches the first duration, it means that the short pause has ended. At this time, the touch state detection unit continues to detect the sensor signal, that is, based on the original signal collected by the current first sensor, it determines again whether the display screen receives the sensor signal, and when it is determined that the display screen receives the sensor signal, it continues to generate a touch state signal and reports it to the processing unit. When it is determined that the display screen does not receive the sensor signal, it continues to generate a non-touch state signal and reports it to the processing unit. At this time, when the processing unit receives the detection result reported by the touch state detection unit again, it can continue to determine whether a touch operation is detected based on the detection result reported by the touch state detection unit and the occlusion data signal reported by the optical detection unit. Optionally, when the sensor signal detected by the touch state detection unit is not the sensor signal when the touch object just contacts the display screen, it will not enter the static phase.

It should be noted that in actual applications, the interactive tablet can select one of the three methods (reselecting the amplified signal, based on the change in the number of blocked light rays, and entering the static stage) for application, or multiple methods can be selected for application. For example, when the processing unit does not receive any signal reported by the touch state detection unit, the optical detection unit is relied on to detect the touch operation. When the processing unit receives a non-touch state signal and generates an occlusion state signal, the touch state detection unit is instructed to reselect the amplified signal. Alternatively, when the processing unit receives a non-touch state signal and generates an occlusion state signal, the touch operation is detected in combination with the change in the number of blocked light rays, and the amplified signal can be reselected during the detection process.

As described above, after the touch state detection unit determines that the surface of the display screen receives the sensor signal at the current moment and does not receive the sensor signal at the previous moment, it enters the static stage. During the static stage, the touch state detection unit no longer reports any detection result. When the processing unit does not receive the detection result reported by the touch state detection unit, it relies on the optical detection unit to detect the touch operation, which can avoid the short pause between the touch object from the pen falling to the movement causing the sensor signal received by the display screen to become hours, the impact on the touch operation detection results, and improved the touch detection accuracy.

The touch detection method provided by the embodiment of the present application is described exemplarily below. FIG. 3 is a schematic diagram of the front of a display screen provided by an embodiment of the present application, and FIG. 4 is a schematic diagram of the back of a display screen provided by an embodiment of the present application. Referring to FIG. 3, an optical detection unit 12 is provided at the edge of the front (image-presenting) side of the display screen 1, and each light emitted by the light emitter of the optical detection unit 12 covers the surface of the display screen 1 and is received by the light receiver of the optical detection unit. Referring to FIG. 4, the back of the display screen 1 corresponds to the part between the display screen 1 and the back shell of the interactive flat panel. The back of the display screen 1 is provided with a first sensor 131 and a processing unit 14 of a touch state detection unit 13, and the touch state detection unit 13 is also provided with a multi-stage amplifier circuit 132 and a signal processing unit (i.e., a touch detection processing subunit) 133. Among them, the multi-stage amplifier circuit is composed of three amplifiers. It should be noted that the first sensor 131 is attached to the back of the glass panel of the display screen, and other devices such as the processing unit 14, the multi-stage amplifier circuit 132 and the signal processing unit 133 are installed inside the interactive flat panel, but may not be attached to the glass panel.

When the user uses a touch pen to write on the display screen, and only the optical detection unit is used to identify the touch operation, the writing trajectory is shown in Figure 5. In Figure 5, the first and second strokes of the character "天" are close to each other. During the user's writing process, the movement of the touch pen leaving the display screen is not obvious. At this time, although the touch pen does not touch the display screen, it still blocks the light. The processing unit will continue to receive the blocking state signal, and determine that the touch operation is detected based on the blocking state signal, and draw the corresponding writing trajectory based on the blocking position.

When the user uses the touch pen to write the same content as in FIG5 on the display screen, the optical detection unit and the touch state detection unit are used to identify the touch operation together. At this time, when the user writes the word "天", between the first stroke and the second stroke, the touch pen leaves the display screen, so the touch state detection unit generates a non-touch state signal. At this time, the processing unit receives the non-touch state signal and generates a blocking state signal. After that, when it is determined that the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, the processing unit instructs the touch state detection unit to reselect a plurality of different levels of amplification signals. If the touch state detection unit still cannot detect the sensing signal after reselection, the processing unit determines that no touch operation is detected. At this time, the writing trajectory is shown in FIG6. Compared with the writing trajectory shown in FIG5, the writing trajectory shown in FIG6 is more consistent with the actual writing of the user.

An embodiment of the present application also provides a touch detection method, which can be executed by a touch detection device. The touch detection device can be implemented by software and/or hardware. The touch detection device can be composed of two or more physical entities, or it can be composed of one physical entity. The touch detection device can be an electronic device with touch function, such as an interactive tablet, a tablet computer, a smart TV, etc. In one embodiment, the touch detection method is described by way of example, taking the touch detection device as an interactive tablet. The interactive tablet includes a display screen, a processing unit, an optical detection unit, and a touch state detection unit. The optical detection unit is a touch state detection unit. The detection unit includes a light transmitter and a light receiver. Each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver. The touch state detection unit includes at least one first sensor. The first sensor includes a mechanical sensor or a vibration sensor. The first sensor is arranged on the side of the display screen facing away from the user.

The difference between the interactive tablet mentioned in this embodiment and the interactive tablet in the above-mentioned embodiment is that, in this embodiment, the touch state detection unit in the interactive tablet performs multi-stage amplification on the original signal collected by the first sensor, and then sends the multi-stage amplified signal to the processing unit, and the processing unit determines to generate a touch state signal or a non-touch state signal according to the multi-stage amplified signal. That is, the touch state detection unit includes the first sensor and the multi-stage amplification circuit, and no longer includes the touch detection processing subunit. Correspondingly, the central processing unit included in the processing unit can have the function of processing the multi-stage amplified signal to detect the sensor signal, or the processing unit also includes a touch detection processing subunit, and the touch detection processing subunit receives the multi-stage amplified signal sent by the touch state detection unit and detects the sensor signal based on the multi-stage amplified signal. In this case, the processing unit may include a touch detection processing subunit and a central processing unit (for generating an occlusion state signal and determining whether a touch operation is received), or includes a touch detection subunit, a central processing unit (for determining whether a touch operation is received) and an optical detection processing subunit (for generating an occlusion state signal). Based on this, FIG. 7 is a flow chart of a touch detection method provided by an embodiment of the present application. Referring to FIG. 7 , the interactive tablet performs the touch detection method including the following steps:

Step 310: The optical detection unit determines a shielding data signal according to the light signal received by the light receiver and reports the shielding data signal to the processing unit.

Step 320: the touch state detection unit performs multi-stage amplification on the original signal collected in real time by the first sensor, and sends the multi-stage amplified signal to the processing unit;

Step 330: The processing unit generates an occlusion state signal according to the occlusion data signal, generates a touch state signal when determining that the surface of the display screen receives the sensing signal according to the amplified signal, and determines that the display screen receives a touch operation according to the occlusion state signal and the touch state signal.

It should be noted that the technical details not described in this embodiment can refer to the relevant description of the previous embodiment, and the only difference is that the content executed by the touch detection processing subunit in the touch state detection unit in the previous embodiment is executed by the processing unit in this embodiment. This embodiment has the same functions and beneficial effects as the previous embodiment, and will not be described in detail at present.

FIG8 is a schematic diagram of the structure of a touch detection device provided by an embodiment of the present application. The touch detection device is applied to an interactive tablet, which includes a display screen, a processing unit, an optical detection unit, and a touch state detection unit. The optical detection unit includes a light transmitter and a light receiver. Each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver. The touch state detection unit includes at least one first sensor, which includes a mechanical sensor or a vibration sensor. The first sensor is arranged on the side of the display screen facing away from the user. Referring to FIG8, the touch detection device includes It includes: a first detection module 401, a second detection module 402, and a third detection module 403.

Among them, the first detection module 401 is configured in the optical detection unit, and is used to determine the occlusion data signal according to the light signal received by the light receiver and report the occlusion data signal to the processing unit; the second detection module 402 is configured in the touch state detection unit, and is used to amplify the original signal collected by the first sensor in real time in multiple stages, and determine based on the multi-stage amplified signal that the surface of the display screen receives the sensing signal, generate a touch state signal, and report the touch state signal to the processing unit; the third detection module 403 is configured in the processing unit, and is used to generate an occlusion state signal according to the occlusion data signal, and determine that the display screen receives a touch operation according to the occlusion state signal and the touch state signal.

In one embodiment, the second detection module 302 includes: a first multi-stage amplification submodule, used to perform multi-stage amplification on the original signal collected by the first sensor in real time to obtain a multi-stage amplified signal; a signal selection submodule, used to select a first-stage amplified signal from the multi-stage amplified signal; a signal generation submodule, used to determine that the surface of the display screen receives the sensing signal according to the signal characteristic parameters of the selected amplified signal, and generate a touch state signal; a signal reporting submodule, used to report the touch state signal to the processing unit.

In one embodiment, the signal selection submodule includes: an overflow rate determination submodule for determining the overflow rate of each stage of amplified signals; and an overflow rate selection submodule for selecting a stage of amplified signals that is less than an overflow rate threshold according to the overflow rates of the amplified signals at each stage.

In one embodiment, the overflow rate determination module includes: an analog-to-digital conversion great-grandson module, which is used to perform analog-to-digital conversion on each stage of the amplified signal to obtain a digitized amplified signal corresponding to each stage of the amplified signal; a statistical great-grandson module, which is used to count the number of signal points in the digitized amplified signal of each stage whose signal value reaches the quantization threshold; and a calculation great-grandson module, which is used to determine the overflow rate of each stage of the digitized amplified signal according to the number of signal points in the digitized amplified signal of each stage whose signal value reaches the quantization threshold and the total number of signal points of the digitized amplified signal of each stage.

In one embodiment, the overflow rate selection module is specifically used to: determine the overflow rate that is less than and closest to the overflow rate threshold among the overflow rates, and use the digitized amplified signal corresponding to the determined overflow rate as the currently selected first-level amplified signal, wherein the digitized amplified signal is a signal obtained after analog-to-digital conversion of the corresponding amplified signal.

In one embodiment, the device further includes: a first selection module, configured in the touch state detection unit, for performing multi-stage amplification on the original signal collected by the first sensor in real time, and after obtaining the multi-stage amplified signals, selecting a first number of amplified signals from the multi-stage amplified signals, wherein the first number is at least two, and the first number of amplified signals are amplified signals with continuous amplification stages; a first reselection module, configured in the touch state detection unit, for determining that when the number of overflow rates higher than the overflow rate range among the first number of amplified signals exceeds the second number, the first number of amplified signals are reselected, and the number of overflow rates exceeding the overflow rate range among the reselected amplified signals does not exceed the second number; or, when the number of overflow rates lower than the overflow rate range among the first number of amplified signals exceeds the second number, the first number of amplified signals are reselected, and the first number of amplified signals are reselected. The number of overflow rates exceeding the overflow rate range in the newly selected amplified signal does not exceed the second number.

In one embodiment, the signal characteristic parameters include peak-to-peak value, energy value and time-frequency point energy ratio, and the signal generation submodule includes: a parameter determination submodule, used to determine the peak-to-peak value, energy value and time-frequency point energy ratio of the selected amplified signal; an external force determination submodule, used to determine that when the peak-to-peak value is greater than the peak-to-peak value threshold or the energy value is greater than the energy threshold, and the time-frequency point energy ratio is greater than the ratio threshold, it is determined that the surface of the display screen receives the sensing signal and generates a touch status signal.

In one embodiment, it also includes: an autocorrelation operation module, configured in the touch state detection unit, for determining that the surface of the display screen receives the sensing signal according to the signal characteristic parameters of the selected amplified signal, before generating the touch state signal, to perform an autocorrelation operation on the selected amplified signal to obtain an autocorrelation calculation result; an operation execution module, configured in the touch state detection unit, for executing an operation of generating a touch state signal according to the selected amplified signal when the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold.

In one embodiment, the operation execution module includes: a pulse detection submodule, which is used to detect a signal segment in the form of a pulse in the selected amplified signal when the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold; a frequency domain transformation submodule, which is used to perform frequency domain transformation on the signal segment to obtain a frequency domain signal segment; a frequency domain selection submodule, which is used to select a sub-frequency domain signal segment within a preset frequency band in the frequency domain signal segment; a time domain transformation submodule, which is used to perform time domain transformation on the sub-frequency domain signal segment to obtain an amplified signal with non-stationary noise filtered out, and execute an operation of determining, based on the signal characteristic parameters of the selected amplified signal, that when the surface of the display screen receives a sensor signal, generating a second state signal based on the sensor signal.

In one embodiment, the time domain transformation module specifically performs a time domain transformation on the sub-frequency domain signal segment when it is determined that the energy value of the sub-frequency domain signal segment is greater than an energy threshold, so as to obtain an amplified signal with non-stationary noise filtered out.

In one embodiment, the device also includes: a fourth detection module, configured in the touch state detection unit, for performing multi-stage amplification on the original signal collected by the first sensor in real time, and when it is determined based on the multi-stage amplified signal that the surface of the display screen has not received the sensing signal, generating a non-touch state signal, and reporting the non-touch state signal to the processing unit; a fifth detection module, configured in the processing unit, for generating an occlusion state signal according to the occlusion data signal at the current moment, and when the non-touch state signal is received, determining the real-time quantity value of the blocked light at the current moment according to the occlusion data signal, and determining the first quantity change value of the blocked light at the current moment according to the real-time quantity value; if the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, it is determined that the display screen has received a touch operation, and the second quantity threshold is greater than the first quantity threshold.

In one embodiment, the device also includes: a sixth detection module, configured in the processing unit, for determining the real-time quantity value of the blocked light at the current moment according to the occlusion data signal, and after determining the first quantity change value of the blocked light at the current moment according to the real-time quantity value, if the first quantity change value is less than the first quantity threshold, the processing unit determines that the display screen has not received a touch operation.

In one embodiment, the device also includes: a quantity calculation module, configured in the processing unit, for determining the real-time quantity value of the blocked light at the current moment according to the occlusion data signal, and after determining the first quantity change value of the blocked light at the current moment according to the real-time quantity value, if the first quantity change value is greater than the second quantity threshold, then continue to calculate the second quantity change value at the next moment; a seventh detection unit, configured in the processing unit, for determining that the display screen has received a touch operation if the second quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold; an eighth detection unit, configured in the processing unit, for determining that the display screen has not received a touch operation if the second quantity change value is less than the first quantity threshold.

In one embodiment, the device further includes: a second selection module, configured in the touch state detection unit, for performing multi-stage amplification on the original signal collected by the first sensor in real time, and after obtaining the multi-stage amplified signals, selecting a third number of amplified signals from the multi-stage amplified signals, the third number is at least two, and the third number of amplified signals are amplified signals with continuous amplification stages; the fifth detection module includes: an occlusion quantity calculation submodule, for generating an occlusion state signal according to the occlusion data signal at the current moment and determining the real-time quantity value of the blocked light at the current moment according to the occlusion data signal when receiving the non-touch state signal, and determining the first number of the blocked light at the current moment according to the real-time quantity value. a signal reselection submodule, for instructing the touch state detection unit to reselect the second number of amplified signals if the first number change value is greater than or equal to the first number threshold and less than or equal to the second number threshold, and selecting a first-level amplified signal from the second number of amplified signals, determining that the surface of the display screen receives the sensing signal according to the selected amplified signal, generating a touch state signal, and reporting the touch state signal to the processing unit, the amplification level of the reselected amplified signal is greater than the amplification level of the amplified signal before the reselection, and the second number threshold is greater than the first number threshold: an operation determination submodule, for determining that the display screen receives a touch operation according to the occlusion state signal and the touch state signal.

In one embodiment, the second detection module 302 includes: a second multi-stage amplification submodule, which is used to perform multi-stage amplification on the original signal collected by the first sensor in real time; a sensor signal detection submodule, which is used to determine that the surface of the display screen receives the sensor signal at the current moment and does not receive the sensor signal at the previous moment based on the multi-stage amplified signal, determine that the touch starts and generates a touch state signal, and reports the touch state signal to the processing unit; a static submodule, which is used to enter the static stage, in which the touch state detection unit stops detecting the sensor signal and stops reporting the detection result to the processing unit; an end submodule, which is used to determine that the static stage ends when the duration of the static stage reaches a first duration, and continue to perform multi-stage amplification based on the original signal collected by the first sensor in real time, and determine that the surface of the display screen receives the sensor signal based on the multi-stage amplified signal, and generate a touch state signal, and report the touch state signal to the central processing unit. The device also includes a seventh detection module, which is configured in the processing unit, and is used to generate an occlusion state signal according to the occlusion data signal in the static stage and does not receive the detection result reported by the touch state detection unit, and determine that the display screen receives a touch operation.

In one embodiment, the device further comprises an eighth detection module, configured in the processing unit, for receiving the touch state When the display screen receives the touch operation, it is determined that the touch operation is not received by the display screen.

A touch detection device provided in one embodiment of the present application is included in an interactive tablet and can be used to execute the touch detection method when the touch state detection unit in the above embodiment generates a touch state signal, and has corresponding functions and beneficial effects.

FIG9 is a schematic diagram of the structure of a touch detection device provided by an embodiment of the present application. The touch detection device is applied to an interactive tablet, which includes a display screen, a processing unit, an optical detection unit, and a touch state detection unit. The optical detection unit includes a light transmitter and a light receiver. Each light emitted by the light transmitter covers the surface of the display screen and is received by the light receiver. The touch state detection unit includes at least one first sensor, which includes a mechanical sensor or a vibration sensor. The first sensor is arranged on the side of the display screen away from the user. Referring to FIG9 , the touch detection device includes: a ninth detection module 404, a tenth detection module 405, and an eleventh detection module 406.

The ninth detection module 404 is configured in the optical detection unit, and is used to determine the occlusion data signal according to the light signal received by the light receiver and report the occlusion data signal to the processing unit; the tenth detection module 405 is configured in the touch state detection unit, and is used to perform multi-stage amplification on the original signal collected by the first sensor in real time, and send the multi-stage amplified signal to the processing unit; the eleventh detection module 406 is configured in the processing unit, and is used to generate an occlusion state signal according to the occlusion data signal, and generate a touch state signal when determining that the surface of the display screen receives the sensing signal according to the amplified signal, and determine that the display screen receives a touch operation according to the occlusion state signal and the touch state signal.

A touch detection device provided in one embodiment of the present application is included in an interactive tablet and can be used to execute the touch detection method when the processing unit generates a touch status signal in the above embodiment, and has corresponding functions and beneficial effects.

It is worth noting that in the embodiment of the above-mentioned touch detection device, the modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be realized; in addition, the specific names of the functional modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

FIG10 is a schematic diagram of the structure of an interactive tablet provided by an embodiment of the present application. As shown in FIG10 , the interactive tablet includes a display 40, a processing unit 41, an optical detection unit 42, and a touch state detection unit 43. The optical detection unit 42 includes a light emitter and a light receiver, and each light emitted by the light emitter covers the surface of the display screen 40 and is received by the light receiver. The touch state detection unit 43 includes at least one first sensor, and the first sensor includes a mechanical sensor or a vibration sensor, and the first sensor is arranged on the side of the display screen 40 away from the user.

The optical detection unit 42 determines the shielding data signal according to the light signal received by the light receiver and reports the shielding data signal to the processing unit; the touch state detection unit 43 performs multi-stage amplification on the original signal collected by the first sensor in real time, and determines based on the multi-stage amplified signal that the surface of the display screen receives the sensing signal, generates a touch state signal, and reports the touch state signal to the processing unit; the processing unit 41 generates a touch state signal according to the shielding data signal The signal generates an occlusion state signal, and determines that the display screen receives a touch operation according to the occlusion state signal and the touch state signal.

Alternatively, the optical detection unit 42 determines the occlusion data signal based on the light signal received by the light receiver and reports the occlusion data signal to the processing unit; the touch state detection unit 43 amplifies the original signal collected by the first sensor in real time in multiple stages, and sends the multiple-stage amplified signals to the processing unit; the processing unit 41 generates an occlusion state signal based on the occlusion data signal, determines based on the amplified signal that a touch state signal is generated when the surface of the display screen receives the sensing signal, and determines based on the occlusion state signal and the touch state signal that the display screen receives a touch operation.

The processing unit 41 may include a processor and a memory; the number of processors may be one or more, and the processor may include a central processing unit, and may also include a microprocessor unit with other functions. The memory, as a computer-readable storage medium, may be used to store software programs, computer executable programs and modules, such as the program instructions/modules corresponding to the processing unit when the interactive tablet executes the touch detection method in the embodiment of the present application. The processor executes various functional applications and data processing of the interactive tablet by running the software programs, instructions and modules stored in the memory. The memory may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory may include a high-speed random access memory and may also include a non-volatile memory. In some instances, the memory may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the interactive tablet via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network and a combination thereof.

The interactive tablet may also include an input device, which may be used to receive input digital or character signals and generate key signal input related to user settings and function control of the interactive tablet. The input device may also be an audio acquisition device such as a microphone. The interactive tablet may also include an output device, which may include an audio playback device such as a speaker. The display screen displays according to the instructions of the processor. The interactive tablet may also include a communication device to realize the communication function.

It should be noted that FIG. 10 only shows the data transmission relationship between the units, and does not show the relative position relationship between the units.

The above-mentioned interactive tablet includes a touch detection device, which can be used to execute the above-mentioned touch detection method and has corresponding functions and beneficial effects.

One embodiment of the present application further provides a storage medium containing computer executable instructions, which, when executed by a computer processor, are used to perform relevant operations in the touch detection method provided in any embodiment of the present application and have corresponding functions and beneficial effects.

Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer programs. Taste.

Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The application is described with reference to the flowchart and/or block diagram of the method, device (system) and computer program product according to the embodiment of the application. It should be understood that each flow and/or box in the flow chart and/or block diagram and the combination of the flow chart and/or box in the flow chart and/or block diagram can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of a computer or other programmable data processing device produce a device for realizing the function specified in one flow chart or multiple flows and/or one box or multiple boxes of a block diagram. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes of the flowchart and/or one or more blocks of the block diagram. These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operating steps are performed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes of the flowchart and/or one or more blocks of the block diagram.

In a typical configuration, a computing device includes one or more processors (CPU), input/output interfaces, network interfaces, and memory. The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and/or non-volatile memory in the form of read-only memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.

Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store signals. Signals can be computer readable instructions, data structures, modules of programs or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store signals that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

A touch detection method, applied to an interactive tablet, characterized in that the interactive tablet comprises a display screen, a processing unit, an optical detection unit and a touch state detection unit, the optical detection unit comprises a light transmitter and a light receiver, each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver, the touch state detection unit comprises at least one first sensor, the first sensor comprises a mechanical sensor or a vibration sensor, and the first sensor is arranged on a side of the display screen away from the user;

The touch detection method comprises:

The optical detection unit determines a shielding data signal according to the light signal received by the light receiver and reports the shielding data signal to the processing unit;

The touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time, and determines based on the multi-stage amplified signal that when the surface of the display screen receives the sensing signal, generates a touch state signal, and reports the touch state signal to the processing unit;

The processing unit generates an occlusion state signal according to the occlusion data signal, and determines whether the display screen receives a touch operation according to the occlusion state signal and the touch state signal.
The touch detection method according to claim 1 is characterized in that the touch state detection unit amplifies the original signal collected by the first sensor in real time in multiple stages, and generates a touch state signal when determining that the surface of the display screen receives the sensing signal based on the multi-stage amplified signal, comprising:

The touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time to obtain multi-stage amplified signals;

The touch state detection unit selects a first-level amplified signal from the multiple-level amplified signals;

The touch state detection unit generates a touch state signal when determining, based on the signal characteristic parameters of the selected amplified signal, that the surface of the display screen receives a sensing signal.
The touch detection method according to claim 2, characterized in that the touch state detection unit selects a first-level amplified signal from the multiple-level amplified signals, comprising:

The touch state detection unit determines an overflow rate of the amplified signal at each level;

The touch state detection unit selects a first-level amplified signal that is less than an overflow rate threshold according to the overflow rates of the amplified signals at each level.
The touch detection method according to claim 3, characterized in that the touch state detection unit determines the overflow rate of the amplified signal at each level, comprising:

The touch state detection unit performs analog-to-digital conversion on each stage of the amplified signal to obtain a digitized amplified signal corresponding to each stage of the amplified signal;

The touch state detection unit counts the number of signal points in each stage of the digital amplified signal whose signal value reaches a quantization threshold;

The touch state detection unit determines the overflow rate of the digital amplified signal at each stage according to the number of signal points whose signal values reach the quantization threshold in the digital amplified signal at each stage and the total number of signal points of the digital amplified signal at each stage.
The touch detection method according to claim 3 is characterized in that the touch state detection unit selects a first-level amplified signal that is less than an overflow rate threshold according to the overflow rate of the amplified signals at each level, comprising:

The touch state detection unit determines the overflow rate that is less than and closest to the overflow rate threshold among the overflow rates, and uses the digitized amplified signal corresponding to the determined overflow rate as the currently selected first-level amplified signal, wherein the digitized amplified signal is a signal obtained after analog-to-digital conversion of the corresponding amplified signal.
The touch detection method according to claim 3 is characterized in that the touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time to obtain the multi-stage amplified signal, and then comprises:

The touch state detection unit selects a first number of amplified signals from the multiple-stage amplified signals, the first number is at least two, and the first number of amplified signals are amplified signals with continuous amplification stages;

After the touch state detection unit determines the overflow rate of the amplified signal at each level, the method includes:

When the touch state detection unit determines that the number of overflow rates exceeding the overflow rate range among the first number of amplified signals exceeds a second number, the first number of amplified signals is reselected, and the number of overflow rates exceeding the overflow rate range among the reselected amplified signals does not exceed the second number.
The touch detection method according to claim 2, characterized in that the signal characteristic parameters include peak-to-peak value, energy value and time-frequency point energy ratio,

The touch state detection unit determines that when the surface of the display screen receives a sensing signal according to the signal characteristic parameter of the selected amplified signal, generating a second state signal according to the sensing signal, including:

The touch state detection unit determines the peak-to-peak value, energy value and time-frequency energy ratio of the selected amplified signal;

When the touch state detection unit determines that the peak-to-peak value is greater than the peak-to-peak value threshold or the energy value is greater than the energy threshold, and the energy proportion of the time-frequency point is greater than the proportion threshold, it determines that the surface of the display screen receives the sensing signal and generates a touch state signal.
The touch detection method according to claim 2 is characterized in that the touch state detection unit determines that when the surface of the display screen receives the sensing signal according to the signal characteristic parameters of the selected amplified signal, before generating the touch state signal, it includes:

The touch state detection unit performs an autocorrelation operation on the selected amplified signal to obtain an autocorrelation calculation result;

When the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold, the touch state detection unit performs the The signal characteristic parameters of the selected amplified signal determine the operation of generating a touch state signal when the surface of the display screen receives the sensing signal.
The touch detection method according to claim 8 is characterized in that when the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold, the touch state detection unit performs an operation of generating a second state signal when determining that the surface of the display screen receives the sensing signal according to the signal characteristic parameter of the selected amplified signal, including:

The touch state detection unit detects a signal segment in the form of a pulse in the selected amplified signal when the maximum value of the autocorrelation calculation result is greater than the autocorrelation threshold;

The touch state detection unit performs frequency domain transformation on the signal segment to obtain a frequency domain signal segment;

The touch state detection unit selects a sub-frequency domain signal segment within a preset frequency band from the frequency domain signal segment;

The touch state detection unit performs a time domain transformation on the sub-frequency domain signal segment to obtain an amplified signal that filters out non-stationary noise, and executes an operation of generating a second state signal when determining, based on the signal characteristic parameters of the selected amplified signal, that the surface of the display screen receives a sensing signal.
The touch detection method according to claim 9, characterized in that the touch state detection unit performs a time domain transformation on the sub-frequency domain signal segment to obtain an amplified signal from which non-stationary noise is filtered, comprising:

When the touch state detection unit determines that the energy value of the sub-frequency domain signal segment is greater than the energy threshold, the sub-frequency domain signal segment is transformed in the time domain to obtain an amplified signal with non-stationary noise filtered out.
The touch detection method according to claim 1, characterized in that after the touch state detection unit amplifies the original signal collected by the first sensor in real time by multiple stages, it also includes:

When the touch state detection unit determines based on the multi-level amplified signal that the surface of the display screen has not received the sensing signal, it generates a non-touch state signal and reports the non-touch state signal to the processing unit;

The touch detection method further includes:

When the processing unit generates an occlusion status signal according to the occlusion data signal at the current moment and receives the non-touch status signal, it determines the real-time quantity value of the blocked light at the current moment according to the occlusion data signal, and determines the first quantity change value of the blocked light at the current moment according to the real-time quantity value; if the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, it is determined that the display screen has received a touch operation, and the second quantity threshold is greater than the first quantity threshold.
The touch detection method according to claim 11 is characterized in that after the processing unit determines the real-time quantity value of the blocked light at the current moment according to the blocking data signal and determines the first quantity change value of the blocked light at the current moment according to the real-time quantity value, it further comprises:

If the first quantity change value is less than the first quantity threshold, the processing unit determines that the display screen has not received to touch operation.
The touch detection method according to claim 11 is characterized in that after the processing unit determines the real-time quantity value of the blocked light at the current moment according to the blocking data signal and determines the first quantity change value of the blocked light at the current moment according to the real-time quantity value, it further comprises:

If the first quantity change value is greater than the second quantity threshold, the processing unit continues to calculate the second quantity change value of the blocked light at the next moment;

If the second quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, the processing unit determines that the display screen receives a touch operation;

If the second quantity change value is smaller than the first quantity threshold, the processing unit determines that the display screen does not receive a touch operation.
The touch detection method according to claim 11, characterized in that after the touch state detection unit amplifies the original signal collected by the first sensor in real time by multiple stages, it also includes:

The touch state detection unit selects a third number of amplified signals from the multi-level amplified signals, the third number is at least two, and the third number of amplified signals are amplified signals with continuous amplification levels;

If the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, the processing unit determines that the display screen receives a touch operation, including:

If the first quantity change value is greater than or equal to the first quantity threshold and less than or equal to the second quantity threshold, the processing unit instructs the touch state detection unit to reselect a third number of amplified signals and select a first-level amplified signal from the third number of amplified signals, determines that the surface of the display screen receives a sensing signal according to the selected amplified signal, generates a touch state signal, and reports the touch state signal to the processing unit, wherein the amplification level of the reselected amplified signal is greater than the amplification level of the amplified signal before the reselection;

The processing unit determines that the display screen receives a touch operation according to the blocking state signal and the touch state signal.
The touch detection method according to claim 1 is characterized in that when the touch state detection unit determines that the surface of the display screen receives the sensing signal based on the multi-level amplified signal, a touch state signal is generated, and reporting the touch state signal to the processing unit comprises:

The touch state detection unit determines, based on the multi-level amplified signal, that the surface of the display screen receives the sensing signal at the current moment and does not receive the sensing signal at the previous moment, determines that the touch starts and generates a touch state signal, and reports the touch state signal to the processing unit;

The touch state detection unit enters a static phase, during which the touch state detection unit stops performing Detection of the sensor signal and stopping reporting the detection result to the processing unit;

When the touch state detection unit determines that the duration of the static phase reaches a first duration, the static phase ends, and continues to perform multi-stage amplification according to the original signal collected in real time by the first sensor, and determines based on the multi-stage amplified signal that the surface of the display screen receives the sensing signal, generates a touch state signal, and reports the touch state signal to the processing unit;

The touch detection method further includes:

In the static stage, when the processing unit generates an occlusion state signal according to the occlusion data signal and does not receive a detection result reported by the touch state detection unit, it determines that the display screen receives a touch operation.
The touch detection method according to claim 1 or 11, characterized in that the touch detection method further comprises:

When the processing unit receives the touch state signal and generates a non-blocking state signal according to the blocking data signal, it is determined that the display screen has not received a touch operation.
A touch detection method is applied to an interactive tablet, characterized in that the interactive tablet comprises a display screen, a processing unit, an optical detection unit and a touch state detection unit, the optical detection unit comprises a light transmitter and a light receiver, each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver, the touch state detection unit comprises at least one first sensor, the first sensor comprises a mechanical sensor or a vibration sensor, and the first sensor is arranged on a side of the display screen away from the user;

The touch detection method comprises:

The optical detection unit determines a shielding data signal according to the light signal received by the light receiver and reports the shielding data signal to the processing unit;

The touch state detection unit performs multi-stage amplification on the original signal collected by the first sensor in real time, and sends the multi-stage amplified signal to the processing unit;

The processing unit generates an occlusion state signal according to the occlusion data signal, generates a touch state signal when determining that the surface of the display screen receives a sensing signal according to the amplified signal, and determines that the display screen receives a touch operation according to the occlusion state signal and the touch state signal.
A touch detection device, applied to an interactive tablet, characterized in that the interactive tablet comprises a display screen, a processing unit, an optical detection unit and a touch state detection unit, the optical detection unit comprises a light transmitter and a light receiver, each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver, the touch state detection unit comprises at least one first sensor, the first sensor comprises a mechanical sensor or a vibration sensor, and the first sensor is arranged on a side of the display screen away from a user;

The touch detection device comprises:

A first detection module, configured in the optical detection unit, for determining a shielding data signal according to the light signal received by the light receiver and reporting the shielding data signal to the processing unit;

a second detection module, configured in the touch state detection unit, for performing multi-stage amplification on the original signal collected by the first sensor in real time, and determining based on the multi-stage amplified signal that the surface of the display screen receives the sensing signal, generating a touch state signal, and reporting the touch state signal to the processing unit;

A third detection module is configured in the processing unit, and is used to generate the blocking state signal according to the blocking data signal, and determine whether the display screen receives a touch operation according to the blocking state signal and the touch state signal.
A touch detection device, applied to an interactive tablet, characterized in that the interactive tablet comprises a display screen, a processing unit, an optical detection unit and a touch state detection unit, the optical detection unit comprises a light transmitter and a light receiver, each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver, the touch state detection unit comprises at least one first sensor, the first sensor comprises a mechanical sensor or a vibration sensor, and the first sensor is arranged on a side of the display screen away from a user;

The touch detection device comprises:

a ninth detection module, configured in the optical detection unit, for determining a shielding data signal according to the light signal received by the light receiver and reporting the shielding data signal to the processing unit;

a tenth detection module, configured in the touch state detection unit, for performing multi-stage amplification on the original signal collected in real time by the first sensor, and sending the multi-stage amplified signal to the processing unit;

An eleventh detection module is configured in the processing unit, and is used to generate the occlusion status signal according to the occlusion data signal, determine according to the amplified signal that a touch status signal is generated when the surface of the display screen receives the sensing signal, and determine that the display screen receives a touch operation according to the occlusion status signal and the touch status signal.
An interactive tablet, characterized in that it comprises a display screen, a processing unit, an optical detection unit and a touch state detection unit, wherein the optical detection unit comprises a light transmitter and a light receiver, each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver, and the touch state detection unit comprises at least one first sensor, wherein the first sensor comprises a mechanical sensor or a vibration sensor, and the first sensor is arranged on a side of the display screen away from a user;

The optical detection unit is used to determine the shielding data signal according to the light signal received by the light receiver and report the shielding data signal to the processing unit;

The touch state detection unit is used to amplify the original signal collected by the first sensor in real time in multiple stages, and determine based on the multi-stage amplified signal that the surface of the display screen receives the sensing signal, generate a touch state signal, and Reporting the touch status signal to the processing unit;

The processing unit is used to generate an occlusion state signal according to the occlusion data signal, and determine whether the display screen receives a touch operation according to the occlusion state signal and the touch state signal.
An interactive tablet, characterized in that it comprises a display screen, a processing unit, an optical detection unit and a touch state detection unit, wherein the optical detection unit comprises a light transmitter and a light receiver, each light beam emitted by the light transmitter covers the surface of the display screen and is received by the light receiver, and the touch state detection unit comprises at least one first sensor, wherein the first sensor comprises a mechanical sensor or a vibration sensor, and the first sensor is arranged on a side of the display screen away from a user;

The optical detection unit is used to determine the shielding data signal according to the light signal received by the light receiver and report the shielding data signal to the processing unit;

The touch state detection unit is used to perform multi-stage amplification on the original signal collected by the first sensor in real time, and send the multi-stage amplified signal to the processing unit;

The processing unit is used to generate the occlusion status signal according to the occlusion data signal, determine according to the amplified signal that the surface of the display screen receives the sensing signal and generate a touch status signal, and determine according to the occlusion status signal and the touch status signal that the display screen receives a touch operation.
A computer-readable storage medium having a computer program stored thereon, characterized in that when the program is executed by a processor, the touch detection method as described in any one of claims 1 to 16 or the touch detection method as described in claim 17 is implemented.