Infrared touch frame circuit board, infrared touch frame and infrared touch screen

Abstract

The present application relates to an infrared touch frame circuit board, an infrared touch frame and an infrared touch screen. The infrared touch frame circuit board comprises a master board and a plurality of slave boards; the master board is provided with a signal attenuation circuit; each slave board is provided with a signal restoration circuit; the master board is connected to each slave board by means of a signal bus; via the signal bus, the master board sends to each slave board a control signal for controlling an infrared emitter / receiver to perform scanning; the signal attenuation circuit attenuates the control signal and then sends same to the slave boards, and the slave boards restore, by means of the signal restoration circuits, the control signal into a high-intensity signal for processing; each slave board superimposes an analog signal acquired by the infrared emitter / receiver onto the signal bus, so as to transmit same to the master board; and the master board extracts the analog signals from the signal bus and uses same for performing touch position determination. The technical solution reduces interference influences of control signals on analog signals, thus improving the sampling quality of infrared light signals, improving the infrared scanning frame rate, and enhancing the performance of infrared touch frames.

Description

Infrared touch frame circuit board, infrared touch frame and infrared touch screen Technical Field

[0001] This application relates to the field of infrared touch technology, and in particular to an infrared touch frame circuit board, an infrared touch frame, and an infrared touch screen. Background Technology

[0002] In the infrared touch frame, multiple sets of infrared photocells are arranged around the display screen. The infrared emitters emit infrared light, and the infrared receivers receive the infrared light signals and convert them into analog signals. The intensity of the infrared light signals is adjusted, and then the infrared light signals are sampled by an analog-to-digital converter. The presence of objects blocking the infrared light is determined by whether there are changes in the adjusted and stabilized signals. This determines the touch operation and calculates the corresponding position coordinates to output, thus enabling functions such as clicking, drawing lines, and touching in the infrared touch frame.

[0003] In infrared touch positioning, the quality of the infrared light signal directly affects the A / D sampling results and is reflected in the performance of the infrared touch frame, such as click accuracy, writing precision, and line drawing effect. Since the analog signal converted from the infrared light signal by the infrared receiver is a weak analog electrical signal, while the control signal controlling the infrared light scanning in the touch frame is a strong digital signal, the data packet after A / D sampling of the infrared light signal on the infrared touch frame circuit board and connecting lines contains interference signals from the control signal. This affects the quality of the analog signal obtained from A / D sampling of the infrared light signal, thus impacting the performance of the infrared touch frame and the infrared touchscreen. Summary of the Invention

[0004] The purpose of this application is to address one of the aforementioned technical deficiencies by providing an infrared touch frame circuit board, an infrared touch frame, and an infrared touch screen to reduce signal crosstalk and improve the performance of the infrared touch frame circuit board.

[0005] An infrared touch frame circuit board includes: a main board and multiple slave boards; the main board is provided with a signal attenuation circuit, and the slave boards are provided with a signal restoration circuit; the main board and each slave board are connected via a signal bus.

[0006] The main board sends control signals to each slave board via a signal bus to control the infrared lamps to scan; wherein, the signal attenuation circuit attenuates the control signals before sending them to the slave boards, and the slave boards use a signal restoration circuit to restore the control signals to strong signals for processing;

[0007] The slave board loads the analog signal collected by the infrared lamp onto the signal bus and transmits it to the host board. The host board extracts the analog signal from the signal bus and uses it for touch positioning.

[0008] An infrared touch frame includes: an infrared touch frame circuit board; wherein the circuit board is connected to an infrared lamp array.

[0009] An infrared touchscreen includes: a display screen and an infrared touch frame; wherein the infrared touch frame surrounds the display screen.

[0010] The technical solution of this application first uses a signal attenuation circuit on the main board to attenuate the control signal before sending it to the slave board. When used on the slave board, the signal is restored to a strong signal by a signal restoration circuit before processing. At the same time, the slave board loads the analog signal converted from the infrared light signal onto the signal bus and sends it back to the main board for centralized processing. This enables the simultaneous transmission of control signals and analog signals on the same circuit board or line in the infrared touch frame, reducing the interference of control signals on analog signals, thereby improving the sampling quality of infrared light signals and enhancing the performance of the infrared touch frame and infrared touch screen. In addition, each slave board sends the analog signal back to the main board for centralized touch positioning processing, simplifying the processing flow of infrared light signals on the slave board, reducing the complexity of processing analog signals on each slave board, resulting in faster response speed and improved infrared scanning frame rate.

[0011] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0012] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0013] Figure 1 is a schematic diagram of the structure of an infrared touch frame circuit board card according to an embodiment;

[0014] Figure 2 is a schematic diagram of the infrared touch frame structure of one embodiment;

[0015] Figure 3 is a circuit structure diagram of a circuit board card according to an embodiment;

[0016] Figure 4 is a schematic diagram of the infrared touch frame structure of another embodiment;

[0017] Figure 5 is a timing diagram of the operation of an infrared touch frame circuit board card according to an embodiment;

[0018] Figure 6 is a schematic diagram of an example PWM synchronization signal. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in this application’s specification means the presence of the stated feature, integer, step, or operation, but does not preclude the presence or addition of one or more other features, integers, steps, or operations.

[0021] The infrared touch frame circuit board provided in this application addresses the issue that, in cascaded circuit board applications, the infrared light signal is a weak analog signal, while the control signal for scanning the infrared lights in the touch frame is a strong digital signal. Since the weak analog signal and the strong digital signal coexist on the same circuit board or the same group of signal buses and their timing overlaps, the control signal can easily interfere with the acquisition of the infrared light signal. Therefore, this application employs a technical solution that attenuates the signal strength of the strong digital signal before restoring it on the circuit board. This avoids the control signal affecting the sampling quality of the infrared light signal during transmission on the digital signal bus. Simultaneously, each slave board transmits the analog signal back to the host board for centralized processing, simplifying the circuit structure of the slave boards and improving the stability of the circuit board.

[0022] Referring to Figure 1, which is a schematic diagram of the structure of an infrared touch frame circuit board card according to an embodiment, the circuit board card includes a main board and multiple slave boards 1 to n, where n≥2; wherein the main board and each slave board are connected through a signal bus, for example, the signal bus in the figure may include a digital signal bus and an analog signal bus; the main board is provided with a signal attenuation circuit and a signal restoration circuit.

[0023] The main board sends control signals to each slave board via a digital signal bus to control the infrared lamps for scanning. The infrared lamps include infrared receivers and infrared transmitters. The slave boards are equipped with infrared transmitters or receivers, corresponding to transmitter boards or receiver boards, respectively. The signal attenuation circuit attenuates the control signal, such as attenuating its intensity by a factor of N before transmission. It can then be sent to each slave board via the digital signal bus. When used on the slave board, the signal restoration circuit restores the control signal to a strong signal, such as amplifying its intensity by a factor of M before processing. This signal is used to control the infrared transmitters for emission and the infrared receivers for scanning. The amplification factor of the control signal should at least meet the intensity requirement that the slave board can normally recognize.

[0024] To better reduce the impact of crosstalk, the signal attenuation circuit is located after the control signal generation circuit on the motherboard to attenuate the generated control signal, while the signal restoration circuit is located near the circuit that needs to use the control signal.

[0025] The infrared receiver tubes on the slave board receive infrared light signals. As shown in the figure, the infrared receiver tubes R of each slave board convert the infrared light signals into analog signals and output them. The slave board loads the analog signals onto the analog signal bus and sends them back to the host board. The host board extracts the analog signals from the analog signal bus and then uses them for touch positioning.

[0026] In one embodiment, the control signal is a low-voltage, high-voltage digital signal, and the analog signal is a weak analog electrical signal obtained by converting infrared light signals received by the infrared receiver tube.

[0027] Because the infrared touch frame enables the simultaneous transmission of control signals and analog signals on the same circuit board or line, the analog signal converted from the infrared light signal received by the infrared receiver can be directly transmitted back to the host board via the analog signal bus for A / D sampling. Each slave board shares the analog signal bus, eliminating the need for separate sampling circuits on each slave board. Compared to the conventional approach of performing analog-to-digital conversion on the slave board before sending it to the host board, this embodiment reduces the digital signal conversion process on the slave board, simplifying the infrared light signal processing flow and significantly improving efficiency. The circuit structure complexity of each slave board is reduced. Because the infrared lamp receives a large amount of infrared light signal data, the conversion from digital signal to digital signal takes a long time. After conversion, due to the large amount of data, the transmission from the slave board to the master board via the digital signal bus takes a long time. The long digital signal bus from each slave board to the master board can easily lead to signal attenuation or distortion and increased transmission time. By converting the infrared light signal received by the infrared lamp from analog signal to digital signal on the slave board, the circuit processing flow is simplified. The analog signals of each slave board are processed on the master board, which improves the response speed and increases the frame rate of infrared scanning.

[0028] Referring to Figure 2, which is a schematic diagram of an infrared touch frame structure according to an embodiment, the main board and slave boards are connected via a digital signal bus and an analog signal bus. As shown in the figure, the infrared touch frame circuit board includes slave boards ① to ⑧. The figure shows the connection circuit between the main board and the slave boards. The infrared lamps on the slave boards can be infrared emitting tubes and / or infrared receiving tubes. Generally, each circuit board is equipped with an infrared emitting tube or an infrared receiving tube. When an infrared emitting tube is installed, the slave board is the emitting board; when an infrared receiving tube is installed, the slave board is the receiving board. All slave boards share the analog signal bus. The main board can be connected to the slave boards as a separate circuit board, or it can be integrated into any slave board and share a circuit board with the slave boards. The example shown in the figure is that the main board is integrated into slave board ⑧. If the main board is a separate circuit board, no infrared lamps are installed on the main board.

[0029] In one embodiment, the signal attenuation circuit may include a passive attenuation circuit or an active attenuation circuit, depending on the requirements of this patent.

[0030] In one embodiment, the signal restoration circuit may include a non-inverting amplifier circuit, an inverting amplifier circuit, a transistor amplifier circuit, or a comparator circuit, etc., which may be determined according to the usage requirements of this patent.

[0031] In one embodiment, as shown in Figure 3, which is a circuit structure diagram of a circuit board card according to an embodiment, the figure shows some circuit components of the main board. The main board includes a signal conditioning circuit, an A / D sampling circuit, and a main MCU (Microprocessor Control Unit) connected in sequence. The signal conditioning circuit is connected to the analog signal bus, and the main MCU is connected to the digital signal bus through a signal attenuation circuit. The slave board is provided with a slave MCU, and an infrared emitting tube or an infrared receiving tube is connected to the slave board. The slave MCU is connected to the digital signal bus through a signal restoration circuit.

[0032] Each slave board is configured with a hardware address. The master MCU and each slave MCU can transmit data through address identification. The master MCU can control the slave MCUs on each slave board to perform scanning operations through a digital signal bus.

[0033] For example, the control signal may include scan data. The working principle of the infrared touch frame circuit board card in the above embodiment can be as follows: Before scanning starts, the main MCU of the host board sends the scan data to the slave MCUs of each slave board through the digital signal bus. Each slave MCU receives its own scan data and stores it. When the slave MCU of each slave board performs the scanning of the infrared lamp tube, it reads the scan data and performs the scanning according to the scan data. Typically, the scan data includes the position information of the infrared receiver and infrared emitter connected to the slave board and the corresponding scanning logic, etc.

[0034] In one embodiment, as shown in FIG4, FIG4 is a schematic diagram of an infrared touch frame structure of another embodiment. Only the circuit part related to the embodiment is shown in the figure. In the infrared touch frame, the host board and multiple slave boards include a digital signal bus, an analog signal bus and a synchronization signal bus.

[0035] When multiple slave boards perform infrared scanning on an infrared touch frame, since different slave boards are responsible for infrared lamps at different locations, in order to distinguish the data from different scans, the main MCU of the main board and the slave MCUs of the slave boards communicate using an address recognition method to achieve data transmission between the devices that need to communicate. For example, before scanning begins, the main board sends different scan data to the corresponding slave boards based on the address recognition method. Accordingly, each slave board is configured with a hardware address. Using the hardware address, the firmware of all slave boards can be unified, and it is convenient to upgrade the firmware of the slave boards. Moreover, only one firmware is needed for all slave boards.

[0036] In one embodiment, the operating timing of the infrared touch frame circuit board card of this application is shown in Figure 5. Figure 5 is a timing diagram of the infrared touch frame circuit board card of one embodiment.

[0037] Before scanning begins, the main MCU on the host board sends the scanning data to the slave MCUs on each slave board via the digital signal bus. Each slave MCU receives and stores its own scanning data. After scanning begins, when the slave MCUs on each slave board are scanning the infrared lamps, the main MCU sends a synchronization signal to the slave MCUs via the synchronization signal bus. After receiving the synchronization signal, the slave MCU parses it, reads the stored scanning data, and performs the scan based on the data. The scanning data includes the position information of the infrared receivers and emitters installed on the slave boards, as well as the corresponding scanning logic. The slave boards directly load the analog signals output by the infrared receivers onto the analog signal bus and transmit them to the host board. The signal conditioning circuit detects the analog signal from the analog signal bus and amplifies and conditions it. The A / D sampling circuit performs A / D sampling on the amplified analog signal to obtain a digital signal, which is then sent back to the main MCU. The main MCU analyzes and processes the digital signal to calculate the coordinate position of the touched object, or uploads it to the host computer to calculate the coordinate position of the touched object.

[0038] As in the above embodiment, the master MCU uses a separate synchronization signal bus to transmit synchronization signals to the slave MCU. The synchronization signal bus can be connected between the signal attenuation circuit and the signal restoration circuit. The master MCU attenuates the synchronization signal through the signal attenuation circuit and then restores it through the amplification and restoration circuit before inputting it to the slave MCU, thereby reducing the impact on the analog signal. The slave MCU uses the synchronization signal to control the corresponding infrared lamps to scan.

[0039] In one embodiment, the synchronization signal can be a PWM synchronization signal; wherein the PWM synchronization signal includes a start signal for synchronous scanning and a PWM pulse signal; referring to Figure 6, which is a schematic diagram of an example PWM synchronization signal, the pulse width of the start signal is different from the PWM pulse width of the light switch. As shown in the figure, the pulse width of the start signal is τ1, the PWM pulse width of the light switch is τ2, and the time interval between them is τ3. The time interval τ3 is used as a buffer time to wait for the slave board to complete the parsing of the start signal and the preparation of the scan data, thereby facilitating the synchronous start scanning control of each slave host; wherein, τ1, τ2, and τ3 are set time widths, for example, τ1 = 4us, τ2 = 0.5us, and τ3 = 59.35us; after the master board transmits the PWM synchronization signal to the slave host, the slave host parses the data of the PWM synchronization signal in real time and starts a frame scan when the start signal is detected.

[0040] As in the above embodiments, by designing start signal structures with different pulse widths and using signal analysis techniques, the main board can drive all slave boards to scan using a single PWM synchronization signal, thus avoiding complex control logic.

[0041] In one embodiment, the signal attenuation circuit of the motherboard can have its attenuation factor set before use. For example, the signal attenuation circuit can be set to attenuate the control signal by N times to obtain an attenuated signal. At the same time, the signal restoration circuit of the slave board can also have its amplification factor set before use. For example, the signal restoration circuit can be set to amplify the attenuated signal by M times to obtain a strong signal, thus meeting the usage requirements. The signal attenuation circuit with its attenuation factor set and the signal restoration circuit with its amplification factor set allow the attenuated signal obtained from the control signal and the weak analog signal obtained from the infrared light signal to be transmitted on the same board without interfering with each other.

[0042] To enable the infrared touch frame circuit board to be used in different scenarios, in one embodiment, the attenuation factor of the signal attenuation circuit of the host board can be dynamically set; the host board can obtain the first strength of the control signal, detect the second strength of the analog signal, and then calculate and set the attenuation factor N of the signal attenuation circuit based on the first strength and the second strength.

[0043] Specifically, the maximum strength of the attenuated signal during shared-board transmission can be determined based on the second strength. Combining this maximum attenuated signal strength with the first strength of the control signal, the attenuation factor N of the signal attenuation circuit can be calculated and dynamically set. Simultaneously, the amplification factor of the signal restoration circuit on the slave board can also be dynamically set. Since the slave board needs to achieve a certain strength requirement when using the amplified and restored synchronization signal, the amplification factor M for the signal restoration circuit to amplify the attenuated signal by a factor of M to obtain a strong signal can be calculated and dynamically set based on the actual strength of the attenuated signal and the minimum strength required by the slave board.

[0044] As described in the above embodiments, by dynamically setting the attenuation factor N and the amplification factor M, the infrared touch frame circuit board can be used in different scenarios, ensuring the stability of the transmission of strong digital signals and analog signals on the same board and improving the functionality of the infrared touch frame.

[0045] The following describes embodiments of the infrared touch frame and infrared touch screen.

[0046] The infrared touch frame of this embodiment includes a main board and multiple slave boards, wherein each slave board is connected to an infrared lamp array, and the main board and each slave board can be connected through a signal bus. For example, the signal bus may include a digital signal bus and an analog signal bus, and may also include a synchronization signal bus.

[0047] The infrared touch frame in the above embodiments uses the infrared touch frame circuit board card of any of the above embodiments, which reduces the interference of control signals on analog signals, thereby improving the sampling quality of infrared light signals, simplifying the processing flow of infrared light signals on the slave board, reducing the complexity of processing analog signals on each slave board, and improving the frame rate of infrared scanning.

[0048] The following describes an embodiment of an infrared touchscreen.

[0049] The infrared touchscreen of this embodiment includes a display screen and an infrared touch frame; wherein the infrared touch frame surrounds the display screen. As in the infrared touchscreen of the above embodiment, the use of the infrared touch frame reduces the interference of control signals on analog signals, thereby improving the sampling quality of infrared light signals, simplifying the processing flow of infrared light signals on the slave board, reducing the complexity of analog signal processing on each slave board, resulting in faster response speed and improved infrared scanning frame rate.

[0050] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0051] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An infrared touch frame circuit board, comprising: A main board and multiple slave boards; characterized in that the main board is provided with a signal attenuation circuit, and the slave boards are provided with a signal restoration circuit; the main board and each slave board are connected via a signal bus; The main board sends control signals to each slave board via a signal bus to control the infrared lamps to scan; wherein, the signal attenuation circuit attenuates the control signals before sending them to the slave boards, and the slave boards use a signal restoration circuit to restore the control signals to strong signals for processing; The slave board loads the analog signal collected by the infrared lamp onto the signal bus and transmits it to the host board. The host board extracts the analog signal from the signal bus and uses it for touch positioning.

2. The infrared touch frame circuit board card according to claim 1, characterized in that, The signal bus includes a digital signal bus and an analog signal bus; The main board sends control signals to each slave board via a digital signal bus; wherein, the signal attenuation circuit is connected to the signal restoration circuit via the digital signal bus. The slave board loads analog signals onto the analog signal bus and transmits them to the host board, and the host board extracts the analog signals from the analog signal bus.

3. The infrared touch frame circuit board card according to claim 2, characterized in that, The motherboard also includes: a signal conditioning circuit, an A / D sampling circuit, and a main MCU connected in sequence; wherein, the signal conditioning circuit is connected to the analog signal bus, and the main MCU is connected to the digital signal bus through a signal attenuation circuit; The slave board is also equipped with a slave MCU; wherein the slave MCU is connected to the digital signal bus through a signal restoration circuit.

4. The infrared touch frame circuit board card according to claim 2, characterized in that, The control signal is a low-voltage, high-voltage digital signal, and the control signal includes scan data; wherein, the main board sends the scan data to each slave board through a digital signal bus.

5. The infrared touch frame circuit board card according to claim 4, characterized in that, The infrared lamp tube includes an infrared emitting tube and an infrared receiving tube; The analog signal is a weak analog electrical signal obtained by converting infrared light signals received by the infrared receiver tube.

6. The infrared touch frame circuit board card according to claim 4, characterized in that, The signal bus also includes a synchronization signal bus; The master MCU sends a synchronization signal to each slave MCU via a synchronization signal bus to trigger the infrared lamps to scan using the scanning data.

7. The infrared touch frame circuit board card according to claim 6, characterized in that, The synchronization signal is a PWM synchronization signal; wherein, the PWM synchronization signal includes a start signal for synchronous scanning and a PWM pulse signal.

8. The infrared touch frame circuit board card according to claim 1, characterized in that, The signal attenuation circuit includes a passive attenuation circuit or an active attenuation circuit.

9. The infrared touch frame circuit board card according to claim 2, characterized in that, The signal restoration circuit includes a non-inverting amplifier circuit, an inverting amplifier circuit, a transistor amplifier circuit, or a comparator circuit.

10. An infrared touch frame, characterized in that, include: The infrared touch frame circuit board card according to any one of claims 1-9; wherein the slave board is connected to an infrared lamp array.

11. An infrared touchscreen, characterized in that, include: The display screen and the infrared touch frame as described in claim 10; wherein the infrared touch frame is disposed around the display screen.

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