Circuit board for infrared touch frame, and infrared touch frame and infrared touch screen

Abstract

The present application relates to a circuit board for an infrared touch frame, and an infrared touch frame and an infrared touch screen. The circuit board comprises: a master board and a plurality of slave boards, wherein an analog signal bus and a digital signal bus are connected between the master board and the slave boards; the master board issues, to each slave board and by means of the digital signal bus, scanning data for controlling an infrared lamp tube; each slave board controls, on the basis of the scanning data, the infrared lamp tube connected to the slave board to perform a scanning operation; the slave board loads, onto the analog signal bus, an analog electrical signal of an infrared light signal that is received by the infrared lamp tube, and transmits the analog electrical signal to the master board; and the master board detects the analog electrical signal from the analog signal bus, and converts the analog electrical signal into a digital signal, which is used for calculating a coordinate position of a touch object. The technical solution simplifies a circuit processing flow, and analog electrical signals output by slave boards are concentrated on a master board for processing, so that the response speed is high, thereby increasing the frame rate of infrared scanning.

Description

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

[0001] The present 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 Art

[0002] The infrared touch frame performs touch positioning and recognition through the emission and reception of infrared lamps. The infrared lamps are installed on the circuit board, as shown in Figure 1. Figure 1 is a schematic diagram of the circuit board connection of an example infrared touch frame. In order to match different lengths and widths, the infrared touch frame is usually composed of multiple circuit boards connected in series through data lines and power lines. The main board is equipped with a main MCU, which can control each slave board. The slave board can be connected to the infrared transmitting tube and / or the infrared receiving tube to transmit and scan the infrared light signal under the control of the main board. In some scenarios, if the slave board is only connected to the infrared receiving tube, it is also called a receiving board, and if it is only connected to the infrared transmitting tube, it is also called a transmitting board.

[0003] During infrared scanning, the mainboard controls the infrared emitting tube of the transmitting board to emit infrared light signals. The infrared receiving tube of the slave board receives the infrared light signals and performs photoelectric conversion to obtain analog electrical signals. The analog electrical signals are amplified and A / D sampled to obtain digital signals. The digital signals are then sent to the main MCU of the mainboard via data lines, and the coordinates of the touched object are calculated. The main MCU of the mainboard is also used to control the working status of each circuit board.

[0004] In the above technical solution, each slave board amplifies and performs A / D sampling on the analog electrical signal obtained by the photoelectric conversion of the infrared receiving tube, and then transmits it to the main board through the data line for processing, which affects the response speed of the infrared touch positioning calculation and reduces the infrared scanning frame rate. Summary of the Invention

[0005] The purpose of this application is to solve one of the above-mentioned technical defects and provide an infrared touch frame circuit board, an infrared touch frame, an infrared touch screen and an electronic device to improve the response speed and the scanning frame rate.

[0006] An infrared touch frame circuit board includes: a main board and multiple slave boards, wherein an analog signal bus and a digital signal bus are connected between the main board and the slave boards, and each slave board communicates data with the main board through the analog signal bus and the digital signal bus;

[0007] The main board sends scanning data for controlling the infrared lamp to each slave board through a digital signal bus; each slave board controls the infrared lamp connected to the slave board to perform scanning according to the scanning data;

[0008] The slave board loads the analog electrical signal corresponding to the infrared light signal received by the infrared lamp onto the analog signal bus and transmits it to the master board;

[0009] The mainboard detects the analog electrical signal from the analog signal bus and converts the analog electrical signal into a digital signal; wherein the digital signal is used to calculate the coordinate position of the touch object.

[0010] In one embodiment, the master board transmits a synchronization signal to each slave board to set at least one of the slave boards to a receiving state; and sequentially sets the other slave boards that are not on the same side as the slave board in the receiving state to a transmitting state.

[0011] In one embodiment, the master board transmits a synchronization signal to each slave board to set at least one infrared receiving tube on one of the slave boards to a receiving state, and to set at least one infrared transmitting tube on other slave boards that are not on the same side as the slave board in the receiving state to a transmitting state.

[0012] In one embodiment, the master board transmits the synchronization signal to the slave board via the digital signal bus or the analog signal bus.

[0013] In one embodiment, before scanning begins, the master board transmits scan data to the slave board via the digital signal bus;

[0014] After scanning starts, the master board and the slave board transmit the synchronization signal via the analog signal bus.

[0015] In one embodiment, before scanning begins, the host board also verifies the scan data with the slave board via the digital signal bus; after the scan data is verified, the host board and the slave board stop communicating via the digital signal bus.

[0016] In one embodiment, before scanning begins, after verification of scan data is completed, the master board transmits the synchronization signal to the slave board via the analog signal bus.

[0017] In one embodiment, the master board attenuates the synchronization signal and transmits the attenuated synchronization signal to the slave board.

[0018] In one embodiment, the slave board receives the attenuated synchronization signal and amplifies and restores the attenuated synchronization signal.

[0019] In one embodiment, upon power-up, the host board verifies scan data with the slave board via the digital signal bus;

[0020] If the verification fails, the master board re-sends the complete scan data to the slave board via the digital signal bus.

[0021] In one embodiment, a synchronization signal bus is connected between the master board and the slave boards; the master board transmits synchronization signals to each slave board via the synchronization signal bus.

[0022] In one embodiment, the synchronization signal is a PWM synchronization signal; wherein the PWM synchronization signal is provided with a start signal of a synchronous scan and a PWM pulse signal, and the pulse width of the start signal is different from the pulse width of the PWM pulse signal for switching the lamp;

[0023] The master board sends a PWM synchronization signal to each slave board. The slave board analyzes the data of the PWM synchronization signal in real time and identifies the start signal. According to the start signal, the infrared transmitting tube of the slave board is triggered to transmit or the infrared receiving tube is controlled to scan.

[0024] In one embodiment, a buffered time interval is set between the start signal and the PWM pulse signal.

[0025] In one embodiment, the main board is provided with a signal conditioning circuit, an A / D sampling circuit and a main MCU connected in sequence;

[0026] The signal conditioning circuit is connected to the analog signal bus; and the main MCU is also connected to the digital signal bus.

[0027] In one embodiment, the signal conditioning circuit is used to detect an analog electrical signal from an analog signal bus and perform amplification and conditioning;

[0028] The A / D sampling circuit is used to perform A / D sampling on the amplified analog electrical signal to obtain a digital signal, and transmit the digital signal to the main MCU through a set protocol.

[0029] In one embodiment, the slave board includes: a slave MCU; the slave MCU controls an infrared transmitting tube and an infrared receiving tube;

[0030] The infrared emitting tube and the infrared receiving tube are arranged at intervals, the infrared emitting tube is connected to the slave MCU, the infrared receiving tube is connected to the analog signal bus, and the slave MCU is also connected to the digital signal bus.

[0031] In one embodiment, the master MCU and each slave MCU perform data transmission based on address identification; wherein each slave board is configured with a hardware address.

[0032] In one embodiment, the master MCU verifies the scan data of the slave boards to which it belongs with each slave MCU through the digital signal bus, and sends a synchronization signal to the slave MCU when the scan data of each slave board is normal, thereby controlling the infrared transmitting tube of the slave board to transmit or the infrared receiving tube to scan.

[0033] In one embodiment, when the master MCU detects that the scan data of the slave board is abnormal, it sends the scan data to the slave MCU of the corresponding slave board;

[0034] The scanning data is received from the MCU and saved.

[0035] In one embodiment, a signal attenuation circuit is further provided on the main board, and a signal amplification and restoration circuit is further provided on the slave board. One end of the signal attenuation circuit is connected to the main MCU, and the other end is connected to the signal amplification and restoration circuit through the analog signal bus. The signal amplification and restoration circuit is connected to the slave MCU.

[0036] In one embodiment, the master MCU outputs the synchronization signal to the signal attenuation circuit, the signal attenuation circuit attenuates the synchronization signal, the analog signal bus transmits the attenuated synchronization signal to the signal amplification and restoration circuit, the signal amplification and restoration circuit restores the attenuated synchronization signal and outputs it to the slave MCU.

[0037] An infrared touch frame comprises: the infrared touch frame circuit board; wherein the slave board is connected to an infrared lamp array.

[0038] An infrared touch screen comprises: a display screen and the infrared touch frame; wherein the infrared touch frame is arranged around the display screen.

[0039] The above-mentioned infrared touch frame circuit board, infrared touch frame and infrared touch screen reduce the processing steps of converting into digital signals on the slave board, simplify the circuit processing process, and the analog electrical signals output by each slave board are concentrated on the host board for processing, which has a fast response speed and improves the frame rate of infrared scanning; further, through the transmission of scanning data and the synchronization signal control mechanism, it can avoid the excessive amount of scanning control signal data transmitted between the host board and the slave board during scanning, thereby meeting the requirements of high-speed scanning.

[0040] Additional aspects and advantages of the present application will be given in part in the following description, which will become apparent from the following description, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0042] FIG1 is a schematic diagram of circuit board connections of an exemplary infrared touch frame;

[0043] FIG2 is a timing diagram of the operation of a circuit board of a conventional infrared touch frame;

[0044] FIG3 is a schematic structural diagram of an infrared touch frame circuit board according to an embodiment;

[0045] FIG4 is a schematic structural diagram of an infrared touch frame circuit board according to another embodiment;

[0046] FIG5 is a timing diagram of the operation of an embodiment;

[0047] FIG6 is a schematic diagram of an example PWM synchronization signal;

[0048] FIG7 is a circuit structure diagram of a mainboard according to an embodiment;

[0049] FIG8 is a circuit diagram of a slave board according to an embodiment;

[0050] FIG9 is a circuit structure diagram of a slave board according to another embodiment;

[0051] FIG10 is a circuit structure diagram of a slave board according to another embodiment;

[0052] FIG11 is a circuit structure diagram of a motherboard according to another embodiment;

[0053] FIG12 is a schematic diagram of an example structure of an infrared touch frame;

[0054] FIG13 is a schematic diagram of an exemplary infrared touch screen structure. DETAILED DESCRIPTION

[0055] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and are not to be construed as limiting the present application.

[0056] Those skilled in the art will understand that, unless otherwise stated, the singular forms "a," "an," "the," and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of this application refers to the presence of the stated features, integers, steps, and operations, but does not preclude the presence or addition of one or more other features, integers, steps, and operations.

[0057] The technical solution of this application is an improvement to the circuit board of an infrared touch frame. In a conventional infrared touch frame, it includes a main control board and a scanning board controlled by the main control board. The main control board is provided with a controller, which is usually an MCU (Microprocessor Control Unit), while the scanning board mainly contains logic circuits and an LED array. As shown in Figure 2, Figure 2 is an operating timing diagram of the circuit board of a conventional infrared touch frame. After the infrared receiving tube R connected to the scanning board receives the infrared light signal, it outputs an analog electrical signal through photoelectric conversion. The analog electrical signal is amplified by the relevant circuit and then A / D sampling is performed to obtain a digital signal of the infrared light signal. The digital signal is then sent to the main control board via a data line. The controller on the main control board calculates the coordinate position of the touched object.

[0058] Since each slave board needs to be equipped with related circuits to amplify the analog electrical signals and perform A / D sampling processing, the overall circuit processing flow is relatively complicated. In addition, since the data line is responsible for controlling the status of each slave board and transmitting digital signals at the same time, the response speed is affected and the frame rate of infrared scanning is easily affected.

[0059] Accordingly, the present application provides an infrared touch frame circuit board, as shown in Figure 3, which is a schematic diagram of the structure of an infrared touch frame circuit board of an embodiment, which mainly includes: a main board and multiple slave boards. The example in the figure includes slave boards ① to ⑧, wherein the slave boards are respectively connected to infrared lamps; an analog signal bus is connected between the main board and the slave boards, and each slave board shares the analog signal bus. The main board and each slave board are also connected through a digital signal bus; exemplarily, the digital signal bus can be an IIC (Inter-Integrated Circuit) data signal bus, which can transmit IIC signals.

[0060] The master board can be connected to the slave board as a separate circuit board, or it can be integrated into any slave board and share a circuit board card with the slave board. As shown in FIG3 , the master board is integrated into the slave board ⑧. If the master board is a separate circuit board card, the infrared lamp is not provided on the master board.

[0061] During the scanning process, the infrared lamp of the slave board receives the infrared light signal and converts the infrared light signal into an analog electrical signal. The slave board loads the analog electrical signal onto the analog signal bus and transmits it back to the main board. The main board detects the analog electrical signal of each slave board from the analog signal bus and converts the analog electrical signal into a digital signal. The main board calculates the corresponding touch object coordinates based on these digital signals, or the main board transmits the digital signal to the host computer (such as an Android mainboard or a Windows mainboard, etc.), which calculates the touch object coordinates.

[0062] Regarding the bus connection between the host board and the slave board, as shown in Figures 3 and 4, Figure 4 is a schematic diagram of the structure of the infrared touch frame circuit board of another embodiment; the host board can transmit synchronization signals to the slave board through a digital signal bus or an analog signal bus. In addition, a separate synchronization signal bus can also be set to transmit synchronization signals. As shown in Figure 4, a synchronization signal bus is connected between the host board and the slave board, and the host board transmits synchronization signals to each slave board through the synchronization signal bus.

[0063] In one embodiment, regarding the use of the digital signal bus and the analog signal bus, before scanning begins, the host board transmits scanning data to the slave board via the digital signal bus; after scanning begins, the host board and the slave board transmit synchronization signals via the analog signal bus.

[0064] In this embodiment, before scanning begins, the main board first sends scanning data to each slave board through the digital signal bus. Each slave board receives its own scanning data and stores it. When performing infrared lamp scanning, each slave board reads the scanning data and performs scanning based on the scanning data. Typically, the scanning data includes the position information of the infrared receiving lamp and infrared transmitting lamp connected to the slave board, as well as the corresponding scanning logic, etc.

[0065] After scanning begins, the master board sends a synchronization signal to each slave board via the analog signal bus to control the corresponding slave board to scan. Specifically, after receiving the synchronization signal sent by the master board, the slave board triggers the start of scanning according to the synchronization signal, reads the scan data stored in itself, and after completing the preparation, controls the working status of the connected infrared receiving tube and infrared transmitting tube according to the synchronization signal.

[0066] In the aforementioned scheme for controlling the slave boards from the master board, after scanning begins, the master board only needs to send a synchronization signal to each slave board to complete scanning control. The small amount of synchronization signal data ensures scanning speed while also ensuring that each slave board can complete precise scanning control. Therefore, after scanning begins, the master board does not need to send different scanning data based on the different scanning conditions of each slave board. This reduces the workload required of the master board and also avoids excessive amounts of scanning control signal data transmitted between the master board and slave boards during scanning, thereby meeting the requirements of high-speed scanning.

[0067] At the same time, after the scan starts, the slave board loads the analog electrical signal output by the infrared lamp when receiving the infrared light signal onto the analog signal bus. If the synchronization signal is transmitted using the digital signal bus, the digital signal bus will cause significant interference to the infrared light signal received by the infrared lamp transmitted on the analog signal bus. Because the synchronization signal and the infrared signal received by the infrared lamp are transmitted at the same time, interference cannot be avoided by adjusting the timing. Therefore, an analog signal bus is used between the master board and the slave board to transmit the synchronization signal to avoid interference.

[0068] In one embodiment, before scanning begins, the host board also verifies the scan data with the slave board via the digital signal bus. After the scan data is verified, communication between the host board and the slave board via the digital signal bus is stopped. Specifically, from the start of scanning to the end of scanning, the digital signal bus between the host board and the slave board stops transmitting signals.

[0069] When the mainboard is powered on, it verifies the scan data with the slave board via the digital signal bus. If the verification passes, the slave board's scan data is available. The slave board reads the scan data and completes scan preparation. The mainboard sends a synchronization signal to trigger the slave board to execute the scan process. If the verification fails, the mainboard resends the complete scan data to the slave board via the digital signal bus. The slave board receives the scan data and completes scan preparation. The mainboard sends a synchronization signal to trigger the slave board to execute the scan process.

[0070] For example, at the time of shipment, the master board has already sent scan data to the slave board. Each subsequent power-up will verify the master board's data with the slave board via a digital signal bus. If the slave board's scan data is normal, the master board determines that the slave board's scan data is valid. If the verified scan data is abnormal, the master board will resend the scan data to the slave board. Furthermore, after each slave board completes a firmware upgrade, the master board will also need to resend scan data to the slave board, which will then receive and store the scan data.

[0071] As in the solution of the above embodiment, the availability of the scan data can be ensured through the verification process, so that the slave board can be in a normal working state when performing the scan, thereby avoiding scan failure.

[0072] In one embodiment, in a scheme where a master board controls the working states of slave boards, the master board transmits a synchronization signal to each slave board to place at least one of the slave boards in a receiving state, and sequentially places the other slave boards located on a different side of the receiving slave board into a transmitting state. At any given moment, only one slave board is in a receiving state, while the other slave boards are in a state of neither transmitting nor receiving. If a slave board is located on the same side as the slave board selected as the receiving board, the slave board neither transmits nor receives during its receiving cycle.

[0073] Because the slave boards are connected to both infrared transmitters and receivers, each slave board can both transmit and receive infrared light signals. Therefore, the master board can use synchronization signals to poll one of the slave boards in a receiving state. At the same moment in the polling cycle, one slave board is put into the transmitting state while the others are put into a non-transmitting and non-receiving state. For group scanning, multiple infrared receivers are activated in groups to receive simultaneously. The infrared receivers of each slave board are then periodically controlled to scan the infrared light signals. This allows for cross-axis scanning, where infrared light is distributed from the X-axis to the Y-axis, making the light distribution more uniform and achieving higher precision.

[0074] For example, in the circuit board structure shown in Figure 3, starting with slave board 1, slave board 1 is set to the receiving state. Slave boards 2 through 7 are then sequentially set to the transmitting state. The infrared emitting diodes on slave boards 2 through 7 transmit in sequence. During the period when slave board 1 is in the receiving state, slave board 8 is neither transmitting nor receiving because it is on the same edge as slave board 1. After the infrared receiving diode connected to slave board 1 has completed scanning, slave board 2 is selected and set to the receiving state. The remaining slave boards are then sequentially set to the transmitting state. This cycle continues, periodically scanning the infrared receiving diodes.

[0075] In one embodiment, the main board can transmit synchronization signals to each slave board to turn on at least one infrared receiving tube connected to one of the receiving boards and turn on at least one infrared transmitting tube connected to one of the transmitting boards.

[0076] Specifically, an infrared transmitting tube or an infrared receiving tube is connected to the slave board, and a synchronization signal is sent to each slave board through the main board to control its working state. When one of the slave receiving boards is set to the receiving state, the infrared receiving tube connected thereto can be controlled to receive infrared light signals. At the same time, according to the scanning requirements, at least one slave board is set to the transmitting state, and the infrared transmitting tube connected thereto can be controlled to transmit infrared light signals, thereby realizing a non-cross-axis scanning mode. At this time, there is no infrared light from the X-axis to the Y-axis in the infrared touch frame.

[0077] For example, in the circuit board structure shown in Figure 3, assuming that slave boards ②, ③, ④, and ⑤ are transmitting boards, and slave boards ⑥, ⑦, ⑧, and ① are receiving boards, any receiving board can be set to a receiving state according to the scanning order and start scanning in sequence. At the same time, the corresponding transmitting board can be set to a transmitting state to control some or all infrared transmitting tubes to transmit infrared light signals, and the infrared receiving tubes can be scanned periodically in this cycle.

[0078] In one embodiment, when controlling the operating states of the slave boards, the master board can transmit synchronization signals to each slave board to place at least one slave board in a receiving state and the other slave boards in a transmitting state. At the same time, at least one slave board is placed in a receiving state and another slave board is placed in a transmitting state, while the other slave boards are placed in a non-transmitting and non-receiving state. If a slave board is located on the same side as a slave board selected as a receiving board, the slave board neither transmits nor receives during the receiving cycle of the receiving board.

[0079] For example, in the circuit board structure shown in Figure 3, assume that at a certain moment, the infrared receiver tube group (composed of multiple infrared receiver tubes) is distributed across slave boards ② and ③. At this time, slave boards ①, ⑧, ⑦, ⑥, ⑤, and ④ are sequentially set to the transmitting state. Placing the infrared receiver tubes of the infrared receiver tube group across the slave boards allows for more flexible lighting layout, without being restricted to the number of infrared receiver tubes being an integer multiple of the sampling channels.

[0080] In one embodiment, the working timing of the infrared touch frame circuit board of the present application is shown in Figure 5. Figure 5 is a working timing diagram of an embodiment. The main board and each slave board transmit scanning data through a digital signal bus, transmit synchronization signals through a digital signal bus, an analog signal bus or a separate synchronization signal bus, and return analog electrical signals through the analog signal bus.

[0081] For example, when multiple slave boards of an infrared touch frame perform infrared scanning, since different slave boards are responsible for infrared lamps at different positions, in order to distinguish the data of different scans, when the main board and the slave board communicate, the data transmission between the devices that need to communicate is realized based on the address recognition method. For example, before the scan starts, the main board sends different scan data to the corresponding slave boards through the digital signal bus based on the address recognition method; accordingly, each slave board is configured with a hardware address. The use of the hardware address can unify the firmware of all slave boards, and facilitate the firmware upgrade of the slave boards. For all slave boards, only one firmware is needed.

[0082] During the scanning process, the slave board loads the analog electrical signal of the infrared lamp onto the analog signal bus and transmits it back to the host board. The host board detects the analog electrical signal from the analog signal bus and converts it into a digital signal. The host board calculates the coordinate position of the touched object or uploads it to the host computer for calculation.

[0083] As in the solution of the above-mentioned embodiment, each slave board shares a common analog signal bus, directly loading analog electrical signals onto the analog signal bus and transmitting them back to the master board for conversion into digital signals. This reduces the processing steps for converting the signals into digital signals on the slave board. At the same time, due to the large amount of data received by the infrared light tubes, converting the analog signals into digital signals takes a long time. After conversion to digital signals, due to the large amount of data, it takes a long time for the slave board to transmit the converted data to the master board via the digital signal bus. The long digital signal bus from each slave board to the master board can easily lead to signal attenuation or distortion, and increase the time consumption. By avoiding the conversion of the infrared light signals received by the infrared light tubes from analog signals into digital signals on the slave board, the circuit processing flow is simplified. The analog electrical signals of each slave board are centrally processed on the master board, resulting in a fast response speed and an improved infrared scanning frame rate.

[0084] In one embodiment, the synchronization signal used by the main board can be a PWM synchronization signal. To ensure that the slave boards scan from the beginning in each frame scan, a start signal for the synchronization scan and a PWM pulse signal are set in the PWM synchronization signal. The pulse width of the start signal is different from the pulse width of the PWM pulse signal for switching the light on and off. The main board sends the PWM synchronization signal to each slave board. The slave board parses the data of the PWM synchronization signal in real time and identifies the start signal. Based on the start signal, the slave board triggers the infrared transmitting tube of the slave board to transmit or controls the infrared receiving tube to scan. Preferably, a buffered time interval is set between the start signal and the PWM pulse signal.

[0085] Refer to Figure 6, which is a schematic diagram of an example PWM synchronization signal, wherein the pulse width of the start signal is different from the PWM pulse width of the switch lamp. As shown in the figure, the pulse width of the start signal is τ1, the PWM pulse width of the switch lamp is τ2, and the time interval between the two is τ3. The time interval τ3 is used to wait for the slave board to complete the start signal analysis and complete the buffer time for scanning data preparation, thereby facilitating the synchronous start of scanning control of each slave host; wherein τ1, τ2, and τ3 are set time widths. In the example of Figure 6, τ1 = 4us, τ2 = 0.5us, and τ3 = 59.35us; after the host 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 recognized.

[0086] As in the above embodiment, if there is no start signal, the synchronization signal cannot be correctly parsed when the slave board is hot-plugged. With the start signal, each frame of the signal can be accurately parsed regardless of whether the slave board is offline. All slave boards will use the start signal of the synchronization signal as a reference for subsequent data parsing.

[0087] In one embodiment, the master board transmits a synchronization signal to the slave board via an analog signal bus. The synchronization signal may be a low voltage difference or low current signal. The master board first attenuates the synchronization signal and then transmits the attenuated synchronization signal to the slave board. The slave board receives the attenuated synchronization signal and amplifies and restores it.

[0088] For example, since the synchronization signal uses a PWM synchronization signal, and in order to ensure that the PWM synchronization signal is transmitted using an analog signal bus during the scanning process to avoid affecting the analog signal generated by the infrared light received by the infrared lamp, the PWM synchronization signal output by the main board can be first attenuated or converted into a signal suitable for analog signal bus transmission on the main board, and then transmitted to the slave board through the analog signal bus, and then amplified or converted on the slave board before use.

[0089] As in the solution of the above embodiment, by attenuation and amplification processing, the influence of the PWM synchronization signal as a strong digital signal on the analog signal is avoided, and the stability of transmission can be improved.

[0090] In order to make the hardware structure of the host board and the slave board of the infrared touch frame circuit board of the present application clearer, several embodiments are described below.

[0091] In one embodiment, a main board is provided with a signal conditioning circuit, an A / D sampling circuit and a main MCU connected in sequence; wherein the signal conditioning circuit is connected to an analog signal bus, and the main MCU is also connected to the digital signal bus; further, the signal conditioning circuit is used to detect an analog electrical signal from the analog signal bus and amplify and condition it; the A / D sampling circuit is used to perform A / D sampling on the amplified analog electrical signal to obtain a digital signal, and transmit it to the main MCU through a set protocol.

[0092] As shown in Figure 7, Figure 7 is a circuit structure diagram of a mainboard of an embodiment, showing the circuit elements of the mainboard part. The mainboard in the figure is provided with 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 also connected to the digital signal bus. Furthermore, the main MCU is connected to the analog signal bus through a signal attenuation circuit. If a separate synchronous signal bus is used to transmit the synchronous signal, the main MCU is connected to the synchronous signal bus through a signal attenuation circuit. For the analog signal bus, it can include multiple parallel signal channels. When the infrared receiving tube adopts a group scanning mode, since there will be multiple infrared receiving tubes outputting analog electrical signals at the same time, each signal channel can transmit each analog electrical signal to the mainboard at the same time.

[0093] Regarding the working principle of the main board, the signal conditioning circuit can be used to detect the analog electrical signal from the analog signal bus and amplify and condition it; the A / D sampling circuit can be used to perform A / D sampling on the amplified analog electrical signal to obtain a digital signal and transmit it back to the main MCU. The main MCU analyzes and processes the A / D sampling data to calculate the coordinate position of the touch object or upload it to the host computer; the main MCU outputs the synchronization signal to the signal attenuation circuit, the signal attenuation circuit attenuates the synchronization signal, and then transmits the attenuated synchronization signal to the slave board through the analog signal bus.

[0094] In one embodiment, a slave board includes: a slave MCU; the slave MCU controls an infrared emitting tube and an infrared receiving tube; wherein the infrared emitting tube and the infrared receiving tube are arranged at intervals, the external emitting tube is connected to the slave MCU, the infrared receiving tube is connected to the analog signal bus, and the slave MCU is also connected to the digital signal bus; further, the master MCU and each slave MCU perform data transmission based on address recognition, and each slave board is configured with a hardware address.

[0095] As shown in Figure 8, Figure 8 is a circuit structure diagram of a slave board according to an embodiment. The slave board includes: a slave MCU, a switch array connecting each infrared emitting tube and infrared receiving tube; wherein the infrared emitting tube and the infrared receiving tube are arranged at intervals, the switch array is connected to the slave MCU, the infrared receiving tube is connected to the analog signal bus through the switch array, and the slave MCU is also connected to the digital signal bus; further, the slave MCU is connected to the analog signal bus through a signal amplification and restoration circuit. If a separate synchronization signal bus is used to transmit the synchronization signal, the slave MCU is connected to the synchronization signal bus through the signal amplification and restoration circuit.

[0096] In the circuit structure shown in FIG8 , the infrared emitting tube array T1, T2, ... T k And infrared receiving tube array R1, R2, ... R kDistributed in an interval manner and connected to the switch arrays P1, P2, ... P 2k ; Infrared emitting tube array T1, T2, ... T k Through the switch array P1, P2, ... P k Connected to slave MCU, switch array P1, P2, ... P k The switch control signals c1, c2, ... c output from the MCU k To control the on or off; the main MCU transmits the attenuated synchronization signal to the signal amplification and restoration circuit through the analog signal bus (or synchronization signal bus), and the signal amplification and restoration circuit outputs the synchronization signal to the slave MCU, and the slave MCU outputs the switch control signal according to the synchronization signal to turn on the infrared emission tube array T1, T2, ... T k Connected to the power line, thus emitting infrared light signals. Infrared receiving tube array R1, R2, ... R k Through the switch array P k+1 , P k+2 , ... P 2k Connected to the analog signal bus, the switch control signal c output from the MCU k+1 , c k+2 , ...c 2k To control the on or off; the output analog electrical signals m1, m2, ... m k After being loaded onto the analog signal bus, the mainboard can directly detect the analog electrical signal from the analog signal bus.

[0097] In one embodiment, as shown in FIG9 , FIG9 is a circuit structure diagram of a slave board of another embodiment, showing circuit elements of the slave board portion. The slave board is a receiving board, which includes a slave MCU and a switch array connected to each infrared receiving tube; wherein the switch array is connected to the slave MCU and is connected to an analog signal bus, and the slave MCU is connected to a digital signal bus.

[0098] In the circuit structure shown in FIG9 , the infrared receiving tube array R1, R2, ... R k Through the switch array P1, P2, ... P k Connected to the analog signal bus, and the switch array P1, P2, ... P k The switch control signals c1, c2, ... c output from the MCU k To control the on or off; the master MCU transmits the attenuated synchronization signal to the signal amplification and restoration circuit through the analog signal bus (or synchronization signal bus), and the signal amplification and restoration circuit outputs the synchronization signal to the slave MCU, and the slave MCU outputs the switch control signal according to the synchronization signal, and outputs the analog electrical signals m1, m2, ... m kAfter being loaded onto the analog signal bus, the mainboard can directly detect the analog electrical signal from the analog signal bus.

[0099] In one embodiment, as shown in FIG10 , FIG10 is a circuit structure diagram of a slave board of another embodiment, showing circuit elements of the slave board portion. The slave board is a transmitting board, which includes a slave MCU and a switch array connected to each infrared transmitting tube; wherein the switch array is connected to the slave MCU, and the slave MCU is connected to a digital signal bus and an analog signal bus.

[0100] In the circuit structure shown in FIG10 , the infrared emitting tube array T1, T2, ... T k , respectively through the switch array P1, P2, ... P k Connected to the main MCU, switch array P1, P2, ... P k The switch control signals c1, c2, ... c output from the MCU k To control the on or off; the main MCU transmits the attenuated synchronization signal to the signal amplification and restoration circuit through the analog signal bus (or synchronization signal bus), and the signal amplification and restoration circuit outputs the synchronization signal to the slave MCU, and the slave MCU outputs the switch control signal according to the synchronization signal to turn on the infrared emission tube array T1, T2, ... T k Turn on to emit infrared light signal.

[0101] In one embodiment, as shown in FIG11 , FIG11 is a circuit structure diagram of a mainboard according to another embodiment, showing circuit elements of the mainboard. In the circuit structure shown in FIG11 , the mainboard can be integrated into a slave board. The mainboard is provided with infrared emitting tubes and / or infrared receiving tubes, and the infrared emitting tube arrays T1, T2, ..., T k , respectively through the switch array P1, P2, ... P k Connected to the main MCU, switch array P1, P2, ... P k The switch control signals c1, c2, ... c output by the main MCU k To control the on or off; the infrared emitting tube array T1, T2, ... T k If a slave board is selected and set to receive state, the infrared receiving tube array R1, R2, ... R k , respectively through the switch array P k+1 , P k+2 , ... P 2k Connected to the analog signal bus, and the switch array P k+1 , P k+2 , ... P 2k The switch control signal c output by the main MCU k+1 , c k+2, ...c 2k To control the on or off; the output analog electrical signals m1, m2, ... m k The signal is loaded onto the analog signal bus, and the signal conditioning circuit amplifies the detected analog electrical signal and outputs the analog electrical signal m to the A / D sampling circuit. The A / D sampling circuit samples it to obtain a digital signal Q and transmits it back to the main MCU for analysis and processing or uploading to the host computer; the main MCU transmits the attenuated synchronization signal to the signal amplification and restoration circuit of the slave board through the analog signal bus (or synchronization signal bus).

[0102] As in the above-described embodiment, scanning data is transmitted between the master MCU and each slave MCU via a digital signal bus, synchronization signals are transmitted via a digital signal bus, an analog signal bus, or a separate synchronization signal bus, and analog electrical signals are returned via the analog signal bus. Each slave board reduces the circuit design required to convert analog electrical signals into digital signals, simplifying the circuit structure and processing flow. The analog electrical signals from each slave board are quickly and directly transmitted back to the circuit structure of the master board for processing, significantly improving processing response speed and thereby increasing the frame rate of infrared scanning.

[0103] In one embodiment, based on the hardware structure of the host board and the slave board of the infrared touch frame circuit board of each embodiment above, the control logic for signal transmission between the master MCU and the slave MCU may specifically include the following:

[0104] During initial use, the master MCU initializes the complete scanning data when it is powered on, reads the address and number of each online slave MCU, and sends the scanning data to each slave MCU through the digital signal bus. The scanning data is used to provide the slave MCU with relevant data and related scanning logic for controlling infrared emission and reception scanning. The corresponding scanning data of the slave MCU is saved. When the slave MCU receives the synchronization signal from the master MCU, it calls the corresponding scanning data to control the infrared transmitting tube of the slave board to transmit or control the infrared receiving tube to scan. For example, when leaving the factory, the master MCU sends scanning data to the slave MCU.

[0105] In daily use, when the machine is powered on, the master MCU first reads the checksum calculated by the slave MCU through the digital signal bus and performs a checksum. Since the position of the infrared lamp controlled by each slave board is different, its scanning task is also different. Therefore, when the main board is powered on, the master MCU uses IIC communication to check with the slave MCU to determine whether the scanning data of each slave board is normal. If it is abnormal, such as the lack of scanning data in the slave MCU, the master MCU sends the scanning data to the slave MCU of the corresponding slave board. After receiving the scanning data, the slave MCU saves it. If the scanning data is normal, it is ready to start scanning. The slave MCU controls the infrared receiving tube or infrared transmitting tube on the slave board based on the scanning data and synchronization signal.

[0106] For example, each time the power is turned on, the master MCU will verify the slave MCU through the digital signal bus. If the scan data on the slave MCU is normal, the master MCU will not send the scan data to the slave MCU. If the scan data is abnormal, the master MCU will resend the scan data to the slave MCU; or after each slave MCU completes the firmware upgrade, the master MCU will resend the scan data to the slave MCU.

[0107] The scanning process is driven by the master MCU, which controls the scanning of each slave MCU through a synchronization signal. The synchronization signal can be a PWM synchronization signal. The slave MCU performs GPIO output according to the PWM synchronization signal and the scanning data, and selects the infrared transmitting tube for transmission or the infrared receiving tube for reception based on this.

[0108] Before scanning begins, the master MCU first performs a verification or sends corresponding scanning data to each slave MCU via a digital signal bus. The scanning data includes the position information of the infrared receiving and infrared transmitting lamps connected to the slave MCU, as well as the corresponding scanning logic. After receiving the synchronization signal sent by the master MCU, the slave MCU begins scanning control based on the synchronization signal and scanning data. The slave MCU interprets the control information of the synchronization signal and controls the connected infrared receiving and infrared transmitting lamps to operate at the appropriate timing.

[0109] After the scan starts, the master MCU only needs to send a PWM synchronization signal to each slave MCU to complete the scan control. The small amount of synchronization signal data ensures the scanning speed while also ensuring accurate scanning control of each slave MCU. For example, after the scan starts, the master MCU does not need to send different scanning data and corresponding scan control signals for different scanning conditions of each slave MCU, which reduces the workload of the master MCU and the amount of scan control signal data communicated between the master MCU and the slave MCU during scanning, thereby achieving high-speed scanning.

[0110] For the analysis and processing of PWM synchronization signals, the MCU receives the PWM synchronization signal sent by the main MCU, first determines the pulse width τ1 to identify the start signal, and after determining the start signal, counts the buffer time interval τ3 set between the start signal and the PWM pulse signal. After the MCU determines the PWM pulse signal, it starts scanning control according to the prepared scanning data, parses the control information of the infrared receiving tube and the infrared transmitting tube, and executes the scanning task until a scanning cycle ends.

[0111] As in the above-mentioned embodiment, the master MCU controls each slave MCU via a single synchronization signal, achieving complex scanning objectives with a simple control method, resulting in high reliability and fast scanning speed. This also reduces the use of logic components, allowing a single MCU to control the scanning status of the transmitting and receiving lamps on a single slave board. This provides high reliability, and a single PWM synchronization signal can drive all slave boards for synchronized scanning, eliminating complex control logic.

[0112] An embodiment of the infrared touch frame is described below.

[0113] The infrared touch frame provided in this application primarily comprises the infrared touch frame circuit board of any of the aforementioned embodiments, and an infrared lamp array connecting the master board and the slave board. As shown in Figure 12, which is a schematic diagram of an exemplary infrared touch frame structure, partially illustrates the structure. In the structure illustrated in the figure, the infrared lamp array comprises an infrared emitting tube array and an infrared receiving tube array, with the infrared emitting tubes and the infrared receiving tubes arranged in an alternate arrangement.

[0114] When in use, the main board can put the slave board connected to one of the slave boards into the receiving state through polling, and put the other slave boards into the transmitting state in turn; using the group scanning method, taking slave board ⑧ as an example, the slave board ⑧ is put into the receiving state. At this time, the upper side (slave board ④ and slave board ⑤), the left side (slave board ⑥ and slave board ⑦) and the right side (slave board ② and slave board ③) are put into the transmitting state in turn. Each slave board is connected to k = 20 infrared transmitting tubes and k = 20 infrared receiving tubes; the corresponding infrared receiving tubes are numbered 1 to 20, and the sampling rate is 100%. Using 5 infrared receiving tubes as a group for scanning, the analog signal bus has 5 signal channels (i.e., 5 independent buses). First, turn on the infrared receiving tubes numbered 1, 2, 3, 4, and 5 to receive the infrared light signal and output 5 analog electrical signals to the analog signal bus for transmission to the main board. Next, turn on the infrared receiving tubes numbered 6, 7, 8, 9, and 10, and so on, to complete the scanning of 20 infrared receiving tubes. Then select slave board ① as the receiving state and use the same method to scan all 20 infrared receiving tubes. The infrared receiving tubes are scanned periodically in this cycle.

[0115] The infrared touch frame of the above embodiment simplifies the circuit processing flow, has a fast response speed, and improves the frame rate of infrared scanning. Through the transmission of scanning data and the synchronization signal control mechanism, it can avoid excessive amount of scanning control signal data transmitted between the host board and the slave board during scanning, thus meeting the requirements of high-speed scanning.

[0116] An embodiment of an infrared touch screen is described below.

[0117] The infrared touch screen provided by the present application is shown in Figure 13. Figure 13 is a schematic diagram of an example infrared touch screen structure, which shows a partial structure, which mainly includes a display screen and an infrared touch frame arranged around the display screen. It can be used on various terminal devices. The display screen can display the picture content. At the same time, the infrared touch frame has a touch positioning function, so that the terminal device used can have a touch function.

[0118] The infrared touch screen of the above embodiment simplifies the circuit processing flow, has a fast response speed, and improves the frame rate of infrared scanning. Through the transmission of scanning data and the synchronization signal control mechanism, it can avoid the excessive amount of scanning control signal data transmitted between the host board and the slave board during scanning, thereby meeting the requirements of high-speed scanning.

[0119] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0120] The above description is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An infrared touch frame circuit board, comprising: A master board and multiple slave boards, wherein an analog signal bus and a digital signal bus are connected between the master board and the slave boards, and each slave board communicates data with the master board via the analog signal bus and the digital signal bus; The main board sends scanning data for controlling the infrared lamp to each slave board through a digital signal bus; each slave board controls the infrared lamp connected to the slave board to perform scanning according to the scanning data; The slave board loads the analog electrical signal corresponding to the infrared light signal received by the infrared lamp onto the analog signal bus and transmits it to the master board; The mainboard detects the analog electrical signal from the analog signal bus and converts the analog electrical signal into a digital signal; wherein the digital signal is used to calculate the coordinate position of the touch object.

2. The infrared touch frame circuit board according to claim 1, characterized in that: The master board transmits a synchronization signal to each slave board to set at least one of the slave boards to a receiving state; and sequentially sets the other slave boards that are not on the same side as the slave board in the receiving state to a transmitting state.

3. The infrared touch frame circuit board according to claim 2, characterized in that: The master board transmits a synchronization signal to each slave board to set at least one infrared receiving tube on one of the slave boards to a receiving state, and to set at least one infrared transmitting tube on another slave board that is not on the same side as the slave board in the receiving state to a transmitting state.

4. The infrared touch frame circuit board according to claim 2, characterized in that: The master board transmits the synchronization signal to the slave board through the digital signal bus or the analog signal bus.

5. The infrared touch frame circuit board according to claim 2, characterized in that: Before scanning begins, the master board transmits scan data to the slave board via the digital signal bus; After scanning starts, the master board and the slave board transmit the synchronization signal via the analog signal bus.

6. The infrared touch frame circuit board according to claim 5, characterized in that: Before scanning begins, the host board also verifies the scan data with the slave board via the digital signal bus; after the scan data is verified, the host board and the slave board stop communicating via the digital signal bus.

7. The infrared touch frame circuit board according to claim 6, characterized in that: Before scanning begins, when verification of scan data is completed, the master board transmits the synchronization signal to the slave board via the analog signal bus.

8. The infrared touch frame circuit board according to claim 2, characterized in that: The master board performs attenuation processing on the synchronization signal and transmits the attenuated synchronization signal to the slave board.

9. The infrared touch frame circuit board according to claim 8, characterized in that: The slave board receives the attenuated synchronization signal and performs amplification and restoration processing on the attenuated synchronization signal.

10. The infrared touch frame circuit board according to claim 1, characterized in that: When powered on, the master board verifies scan data with the slave board via the digital signal bus; If the verification fails, the master board re-sends the complete scan data to the slave board via the digital signal bus.

11. The infrared touch frame circuit board according to claim 2, characterized in that: A synchronization signal bus is connected between the master board and the slave boards; the master board transmits synchronization signals to each slave board via the synchronization signal bus.

12. The infrared touch frame circuit board according to claim 2, characterized in that: The synchronization signal is a PWM synchronization signal; wherein the PWM synchronization signal is provided with a start signal of a synchronous scan and a PWM pulse signal, and the pulse width of the start signal is different from the pulse width of the PWM pulse signal for switching the lamp; The master board sends a PWM synchronization signal to each slave board. The slave board analyzes the data of the PWM synchronization signal in real time and identifies the start signal. According to the start signal, the infrared transmitting tube of the slave board is triggered to transmit or the infrared receiving tube is controlled to scan.

13. The infrared touch frame circuit board according to claim 12, characterized in that: A buffer time interval is set between the start signal and the PWM pulse signal.

14. The infrared touch frame circuit board according to claim 1, characterized in that: The main board is provided with a signal conditioning circuit, an A / D sampling circuit and a main MCU connected in sequence; The signal conditioning circuit is connected to the analog signal bus; and the main MCU is also connected to the digital signal bus.

15. The infrared touch frame circuit board according to claim 14, characterized in that: The signal conditioning circuit is used to detect analog electrical signals from the analog signal bus and perform amplification and conditioning; The A / D sampling circuit is used to perform A / D sampling on the amplified analog electrical signal to obtain a digital signal, and transmit the digital signal to the main MCU through a set protocol.

16. The infrared touch frame circuit board according to claim 14, characterized in that: The slave board includes: a slave MCU; the slave MCU controls the infrared transmitting tube and the infrared receiving tube; The infrared emitting tube and the infrared receiving tube are arranged at intervals, the infrared emitting tube is connected to the slave MCU, the infrared receiving tube is connected to the analog signal bus, and the slave MCU is also connected to the digital signal bus.

17. The infrared touch frame circuit board according to claim 16, characterized in that: The master MCU and each slave MCU perform data transmission based on an address identification method; wherein each slave board is configured with a hardware address.

18. The infrared touch frame circuit board according to claim 16, characterized in that: The master MCU verifies the scan data of the slave boards with each slave MCU through the digital signal bus, and sends a synchronization signal to the slave MCU when the scan data of each slave board is normal, controlling the infrared transmitting tube of the slave board to transmit or the infrared receiving tube to scan.

19. The infrared touch frame circuit board according to claim 16, characterized in that: When the master MCU detects that the scanning data of the slave board is abnormal, it sends the scanning data to the slave MCU of the corresponding slave board; The scanning data is received from the MCU and saved.

20. The infrared touch frame circuit board according to claim 16, characterized in that: The host board is also provided with a signal attenuation circuit, and the slave board is also provided with a signal amplification and restoration circuit. One end of the signal attenuation circuit is connected to the master MCU, and the other end is connected to the signal amplification and restoration circuit through the analog signal bus. The signal amplification and restoration circuit is connected to the slave MCU.

21. The infrared touch frame circuit board according to claim 20, characterized in that: The master MCU outputs the synchronization signal to the signal attenuation circuit, the signal attenuation circuit attenuates the synchronization signal, the analog signal bus transmits the attenuated synchronization signal to the signal amplification and restoration circuit, the signal amplification and restoration circuit restores the attenuated synchronization signal and outputs it to the slave MCU.

22. An infrared touch frame, characterized in that: include: The infrared touch frame circuit board according to any one of claims 1 to 21; wherein the slave board is connected to an infrared lamp array.

23. An infrared touch screen, characterized in that: include: A display screen and the infrared touch frame according to claim 22; wherein the infrared touch frame is arranged around the display screen.

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