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

Abstract

The present disclosure provides an infrared touch frame circuit board, an infrared touch frame and an infrared touch screen. The specific implementation scheme of the infrared touch frame circuit board is: it includes a main board and multiple slave boards, the main board is connected in series with the slave board through a scan data bus and a slave resistor corresponding to the slave board in sequence, and the main board is connected to the slave board through a synchronous scan signal bus; the main board is used to determine the address information of the slave board based on the slave resistor corresponding to the slave board, and based on the address information, sends the scan data to the slave board through the scan data bus; the main board is also used to send a synchronous scan signal to each slave board through the synchronous scan signal bus; the slave board is used to receive the scan data, and when the synchronous scan signal is received, the infrared lamp in the slave board is controlled to perform scanning according to the scan data. The technical solution of the present disclosure is adopted to reduce the connection pins between the host and the slave.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, in particular to the field of touch detection. The present disclosure specifically relates to an infrared touch frame circuit board, an infrared touch frame and an infrared touch screen. Background Art

[0002] The infrared touch frame of a large touch screen can be made of multiple boards, and each board can have both a transmitting lamp and a receiving lamp. During scanning, a main MCU controller controls each board to perform a scanning operation of transmitting or receiving. Logic devices are set in each board to implement the logic of scanning control. However, due to structural factors, the connector on the board has a pin number requirement, and it is impossible to connect a main MCU to many boards. Summary of the invention

[0003] The present disclosure provides an infrared touch frame circuit board, an infrared touch frame and an infrared touch screen.

[0004] According to one aspect of the present disclosure, there is provided an infrared touch frame circuit board, comprising:

[0005] It includes a main board and a plurality of slave boards, wherein the main board is connected in series with the slave boards through a scan data bus and slave resistors corresponding to the slave boards in sequence, and the main board is connected with the slave boards through a synchronous scan signal bus;

[0006] The host board is used to determine the address information of the slave board based on the slave resistance corresponding to the slave board, and send the scan data to the slave board through the scan data bus based on the address information;

[0007] The main board is also used to send a synchronous scanning signal to each of the slave boards through the synchronous scanning signal bus;

[0008] The slave board is used to receive the scanning data, and when receiving the synchronous scanning signal, controls the infrared lamp in the slave board to perform scanning according to the scanning data.

[0009] According to another aspect of the present disclosure, an infrared touch frame is provided, comprising: the infrared touch frame circuit board according to any one of the embodiments of the present disclosure, and an infrared lamp array connecting a main board and a plurality of slave boards in the infrared touch frame circuit board.

[0010] According to another aspect of the present disclosure, an infrared touch screen is provided, comprising: a display screen and the infrared touch frame described in any one of the embodiments of the present disclosure, wherein the infrared touch frame is arranged around the display screen.

[0011] According to the technology disclosed in the present invention, the infrared touch frame circuit board includes a main board and a plurality of slave boards, the main board is connected in series with the slave board through a scan data bus and a slave resistor corresponding to the slave board in sequence, and the main board is connected to the slave board through a synchronous scan signal bus. In this way, the main board can determine the address information of the slave board through the slave resistor corresponding to the slave board, and the main board sends corresponding scan data to each slave board through the scan data bus based on the address information of each slave board. Subsequently, the main board can send a synchronous scan signal to each slave board through the synchronous scan signal bus, so that each slave board responds to the synchronous scan signal synchronously, and controls the infrared lamp in the slave board to perform scanning according to the corresponding scan data. Moreover, the connection line between the main board and each slave board is simple, and it is not necessary to occupy too many pins of the main board, so that the scan data can be accurately sent to each slave board, so that the synchronous scan can be realized by sending the synchronous scan signal through only one synchronous scan signal bus in the future.

[0012] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure.

[0014] Figure 1 is a schematic diagram of an infrared touch frame circuit board according to an embodiment of the present disclosure;

[0015] Figure 2 is a schematic diagram of an infrared touch frame circuit board according to another embodiment of the present disclosure;

[0016] Figure 3 is a schematic diagram of an infrared touch frame circuit board according to another embodiment of the present disclosure;

[0017] Figure 4 is a schematic diagram of a PWM synchronous scanning signal according to an embodiment of the present disclosure;

[0018] Figure 5 Schematic diagram of an infrared touch frame structure according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope of the present disclosure. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0020] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, but does not exclude the presence or addition of one or more other features, integers, steps, operations.

[0021] Figure 1 Schematic diagram of an infrared touch frame circuit board according to an embodiment of the present disclosure. Figure 2 Schematic diagram of an infrared touch frame circuit board according to another embodiment of the present disclosure.

[0022] like Figure 1 As shown, in the infrared touch frame, multiple groups of infrared tube pairs are arranged around, and many infrared emitting lamps and / or infrared receiving lamps are distributed on the boards that are spliced ​​end to end. Since the length of a single PCB is limited, the boards are connected by connectors and spliced ​​into longer sides. Among them, the multiple boards are the main board and the multiple slave boards. If only an infrared emitting lamp array is set on a board, this board is generally called an infrared emitting board. If only an infrared receiving lamp array is set on a board, this board is generally called an infrared receiving board. In some cases, the infrared tube array on a board is provided with both infrared emitting lamps and infrared receiving lamps, depending on the suitability for different overall technical solutions. As Figure 2 As shown, each board controls the infrared emitting lamp, infrared receiving lamp and / or the row and column matrix of the infrared receiving lamp through the shift register and the decoder. By controlling the shift register and the decoder, each infrared emitting lamp or infrared receiving lamp can be precisely controlled. Then, the infrared signal received by the infrared receiving lamp is sampled, and it is judged whether there is an object blocking the infrared light according to whether the signal after adjustment and stabilization changes. In this way, the touch operation is judged, and the corresponding position coordinates are output, so as to realize the touch, writing and other functions of the infrared touch frame.

[0023] like Figure 2 As shown, each board generally has 6 to 8 columns of infrared emitting lamps and / or infrared receiving lamps. Each column of infrared emitting lamps or infrared receiving lamps requires a pin to control, and also requires a pin for clearing or other functions. Figure 1 As shown in the figure, it shows the connection relationship between boards. Since each board is connected through a connection terminal, if the control pins and other functional pins for the infrared transmitting lamp or infrared receiving lamp and / or infrared receiving lamp array are directly controlled by the microprocessor (MCU), the number of pins of the connection terminal is insufficient. Figure 2As shown, for each board in the infrared touch frame, the control circuit controls the shift register and the decoder through the controller, and uses Q0, Q1...Qn of the shift register as the row control signal, which uses the serial bus CLK (clock signal), DATA (data signal), and MR (clear signal). The decoder is used as a column control chip, and uses Y0, Y1...Yn as the column control signal, which uses the parallel lines A0\A1\A2 (address lines) and EN (enable lines) to reduce the total number of control lines from the microprocessor (MCU) to each board to meet the requirements of the limit on the number of pins of the connection terminals. Since each board must be equipped with a shift register and a decoder at the same time to reduce the number of pins of the connection terminals between boards, the requirements of the existing connection terminals are met, but the cost is high and the control is complicated.

[0024] Figure 3 Schematic diagram of an infrared touch frame circuit board according to another embodiment of the present disclosure.

[0025] like Figure 3 As shown, the infrared touch frame circuit board includes a main board and multiple slave boards. The example in the figure includes slave boards ① to ⑦. A plurality of infrared lamps are arranged on the main board and each slave board. The infrared lamp can be an infrared transmitting tube and / or an infrared receiving tube. The main board is connected in series with the slave board through a scanning data bus and a slave resistor corresponding to the slave board in sequence. For example, a scanning data bus is set, the main board is connected to the scanning data bus, and each slave board is connected to the scanning data bus through a slave resistor. Exemplarily, the scanning data bus can be an IIC (Inter-Integrated Circuit) data signal bus, which can transmit an IIC signal.

[0026] The slave resistors corresponding to the slave boards are different from each other, so that the slave resistors are actually used to identify the address information of the slave boards.

[0027] At the same time, the main board is also connected to each slave board through a synchronous scanning signal bus to transmit synchronous scanning signals to each slave board. For example, a synchronous scanning signal bus is set, the main board is connected to the synchronous scanning signal bus, and each slave board is also connected to the synchronous scanning signal bus.

[0028] The host board can be connected to the slave board as a separate circuit board, or can be integrated into any slave board and share a circuit board card with the slave board. If the host board is a separate circuit board card, the infrared lamp tube may not be set on the host board.

[0029] During the operation of the infrared touch frame circuit board, the host board determines the address information of each slave board based on the slave resistance corresponding to each slave board, and sends the corresponding scanning data to each slave board through the scanning data bus based on the address information corresponding to each slave board. Then, the host board sends a synchronous scanning signal to each slave board through the synchronous scanning signal bus. The slave board receives the scanning data, and when receiving the synchronous scanning signal, controls the infrared lamp in the slave board to perform scanning according to the scanning data to obtain touch data.

[0030] The main board may send the scan data corresponding to each slave board to each slave board in sequence.

[0031] In this embodiment, before scanning begins, the host board sends corresponding scanning data to each slave board through the scanning data bus and the slave electrical group of each slave board. Each slave board receives its own scanning data and stores it. When performing the scanning of the infrared lamp tube, each slave board reads the scanning data and performs scanning according to the scanning data. Generally, the scanning data includes the position information of the infrared receiving lamp and the infrared transmitting lamp in the slave board and the corresponding scanning logic, etc.

[0032] After the scanning starts, the main board sends a synchronous scanning signal to each slave board through the synchronous scanning data bus to trigger each slave board to control the infrared lamp in the slave board to scan based on the scanning data stored therein. Specifically, after receiving the synchronous scanning signal sent by the main board, the slave board starts scanning according to the synchronous scanning signal trigger, reads the scanning data stored by itself, and after completing the preparation, controls the working state of the connected infrared receiving tube and infrared transmitting tube according to the synchronous scanning signal.

[0033] According to the above embodiment, the main board is connected to each slave board through different pull-up resistors, the connection line is simple, and it is not necessary to occupy too many pins of the main board, so that the scanning data can be accurately distributed to each slave board. In this way, later, a synchronous scanning signal is sent to each slave board through a synchronous scanning signal line, and each slave board can realize synchronous scanning. The data volume of the synchronous scanning signal is small, so as to ensure the scanning speed while ensuring that each slave board can complete accurate scanning control. Therefore, after the scanning starts, the main board does not need to send different scanning data for different scanning conditions of each slave board, which reduces the workload requirements of the main board on the one hand, and also avoids the excessive amount of scanning control signal data transmitted between the main board and the slave board during scanning, so as to meet the requirements of high-speed scanning.

[0034] In some embodiments, each slave board can send the touch data obtained by each slave board to the host board by scanning the data bus, and the host board calculates the coordinate position of the touch object based on the touch data provided by each slave board. In some embodiments, the touch data can be an analog signal, and the host board converts the analog signal into a digital signal, and then calculates the data signal to obtain the coordinate position of the touch object.

[0035] In some embodiments, the synchronous scanning signal may be an analog signal. After the scanning starts, the slave board loads the analog electrical signal output by the infrared lamp tube receiving the infrared light signal onto the analog signal bus. If the synchronous scanning signal is transmitted using a digital signal, the touch data transmitted on the scanning data bus will cause significant interference to the infrared light signal received by the infrared lamp tube transmitted on the synchronous scanning signal bus. Because the synchronous scanning signal and the infrared signal received by the infrared lamp tube are transmitted at the same time, interference cannot be avoided by adjusting the timing. Therefore, using an analog signal bus between the host board and the slave board to transmit the synchronous scanning signal can avoid interference.

[0036] In some embodiments, before scanning begins, the host board may also verify the scan data with the slave board via the scan data bus.

[0037] When the host board is powered on, the host board verifies the scan data with the slave board through the scan data bus. If the verification is successful, it means that the scan data of the current slave board is available. The slave board reads the scan data and completes the scan preparation. The host board sends a synchronous scan signal through the synchronous scan signal bus to trigger each slave board to synchronously execute the scan process. If the verification fails, the host board re-sends the corresponding scan data to the slave board through the scan data bus. The slave board receives the scan data and completes the scan preparation. The host board sends a synchronous scan signal to trigger each slave board to synchronously execute the scan process.

[0038] For example, when the machine is shipped from the factory, the main board has already sent the scan data to the slave board; each time the machine is powered on, the main board will verify the data with the slave board through the scan data bus. If the scan data on the slave board is normal, the main board will determine that the scan data of the slave board is available. If the scan data is abnormal, the main board will send the scan data to the slave board again. In addition, after the firmware upgrade of each slave board is completed, the main board also needs to send the scan data to each slave board again, and the slave board will receive the scan data and save it.

[0039] 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 the scan failure.

[0040] In some embodiments, the synchronous scanning signal used for the main board can be a PWM signal. The PWM signal is provided with a start signal of the synchronous scanning and a PWM pulse signal, so that each slave board can synchronously trigger the scanning process from the start signal. The pulse width of the start signal is different from the pulse width of the PWM pulse signal.

[0041] The main board sends a PWM signal to each slave board, and each slave board receives the PWM signal. In response to the start signal in the PWM signal, each slave board is synchronously triggered to start controlling the infrared transmitting tube in the slave board to transmit signals or the infrared receiving tube to receive signals based on the PWM pulse signal in the PWM signal and the corresponding scanning data.

[0042] In some embodiments, a buffered time interval is set between the start signal and the PWM pulse signal.

[0043] refer to Figure 4 As shown, Figure 4 This is an example of a PWM synchronous scanning signal diagram, where the pulse width of the start signal is different from the PWM pulse width of the switch lamp (infrared 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 the buffer time to complete the scan data preparation, so as to facilitate the synchronization of each slave host to start scanning control. Among them, τ1, τ2, τ3 are the set time widths. Figure 4 In the example, τ1=4us, τ2=0.5us, τ3=59.35us; after the host board transmits the PWM synchronous scanning signal to the slave host, the slave host parses the data of the PWM synchronous scanning signal in real time and starts a frame scan when the start signal is recognized.

[0044] As in the above embodiment, if there is no start signal, when the slave board is hot-plugged, the synchronous scanning signal cannot be correctly parsed; after the start signal is provided, regardless of whether the slave board is offline in the middle, each frame signal can be accurately parsed, and all slave boards will use the start signal of the synchronous scanning signal as a reference for subsequent data parsing.

[0045] In one embodiment, the main board transmits a synchronous scanning signal to the slave board through an analog signal bus. The synchronous scanning signal can be a low voltage difference or low current signal. The main board first attenuates the synchronous scanning signal and then transmits the attenuated synchronous scanning signal to the slave board; the slave board receives the attenuated synchronous scanning signal and amplifies and restores it.

[0046] For example, since the synchronous scanning signal adopts the PWM synchronous scanning signal, and in order to ensure that the PWM synchronous scanning signal is transmitted using the 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 synchronous scanning 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.

[0047] As in the solution of the above embodiment, by attenuation and amplification processing, the influence of the PWM synchronous scanning signal as a strong digital signal on the analog signal is avoided, and the stability of transmission can be improved.

[0048] In order to make the hardware structure of the host board and the slave board of the infrared touch frame circuit board in this application clearer, several embodiments are described below.

[0049] In one embodiment, a main board is provided with a signal conditioning circuit, an A / D sampling circuit and a main MCU which are 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.

[0050] In some embodiments, for the scheme of the main board controlling the working state of the slave board, the main board is used to send corresponding scanning data to each slave board based on the address information of each slave board, so that at least one slave board is set to a receiving state, and other slave boards that are not on the same side as the slave board in the receiving state are set to a transmitting state. In this way, at the same time, only one slave board on the same side of the infrared touch frame is set to a receiving state, while the other slave boards are set to a transmitting state or 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, it neither transmits nor receives during the receiving cycle of the slave board.

[0051] In some embodiments, the receiving state is that at least one infrared receiving tube in the corresponding slave board is in a state of allowing operation (allowing connection state), and all infrared transmitting tubes in the corresponding slave board are in a state of prohibiting operation (prohibiting emission state). The transmitting state is that all infrared receiving tubes in the corresponding slave board are in a state of prohibiting operation (prohibiting connection state), and at least one infrared transmitting tube in the corresponding slave board is in a state of allowing operation (allowing emission state).

[0052] Since the slave boards are connected to both infrared transmitting tubes and infrared receiving tubes, each slave board can transmit and receive infrared light signals. Therefore, the master board can set one of the slave boards to the receiving state by scanning data, and at the same time, set one slave board to the transmitting state, while setting the other slave boards to neither transmit nor receive. If group scanning is performed, multiple infrared receiving tubes are turned on in groups to receive at the same time; then the infrared receiving tubes of each slave board are periodically controlled to scan the infrared light signal; in this way, cross-axis scanning can be achieved, that is, there is infrared light from the X-axis to the Y-axis, making the light part more uniform and more accurate.

[0053] For example, Figure 3 In the circuit board structure shown, starting from slave board ①, slave board ① is set to the receiving state, and slave boards ② to ⑦ are set to the transmitting state in turn, and the infrared transmitting tubes on slave boards ② to ⑦ transmit in turn. During the period when slave board ① is in the receiving state, if slave board ⑧ is integrated into the main board, since slave board ⑧ and slave board ① are on the same side, slave board ⑧ neither transmits nor receives. After the infrared receiving tube connected to slave board ① is scanned, slave board ② is selected to be set to the receiving state, and the other slave boards are set to the transmitting state in turn; the infrared receiving tubes are scanned periodically in this cycle.

[0054] In one embodiment, the main board can transmit scanning data to each slave board, set at least one infrared receiving tube connected to one of the receiving boards to an on state (a state allowing work), and set at least one infrared transmitting tube connected to one of the transmitting boards to an transmitting state (a state allowing work).

[0055] Specifically, an infrared transmitting tube or an infrared receiving tube is connected to the slave board, and scanning data is sent to each slave board through the main board to control its working state. One of the slave receiving boards is set to the receiving state, and the infrared receiving tube connected to it 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 to it can be controlled to emit 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.

[0056] For example, Figure 3 In the circuit board structure shown, it is assumed that slave boards ②, ③, ④ and ⑤ are transmitting boards, and slave boards ⑥, ⑦, ⑧ (integrated in the main board) and ① are receiving boards. Any receiving board can be set to a receiving state according to the scanning sequence, and scanning can be started in sequence. At the same time, the corresponding transmitting board is set to a transmitting state to control several or all infrared transmitting tubes to transmit infrared light signals, and the infrared receiving tubes are scanned periodically in this way.

[0057] In one embodiment, when the main board controls the working state of the slave board, the main board can transmit a synchronous scanning signal to each slave board to set at least one of the slave boards to a receiving state and the other slave boards to a transmitting state in sequence, and at the same time, at least one slave board is set to a receiving state and another slave board is set to a transmitting state, while the other slave boards are set to a state of neither transmitting nor receiving. If a slave board and a slave board selected as a receiving board are located on the same side, the slave board neither transmits nor receives during the receiving cycle of the receiving board.

[0058] For example, Figure 3 In the circuit board structure shown, it is assumed that the infrared receiving tube group (composed of multiple infrared receiving lamps) is distributed across slave board ② and slave board ③ at a certain moment. At this time, slave board ①, slave board ⑧, slave board ⑦, slave board ⑥, slave board ⑤, and slave board ④ are set to the transmitting state in sequence. The infrared receiving lamps of the infrared receiving tube group are arranged across the slave boards, and the lamp arrangement is more flexible, and is not limited to the number of infrared receiving lamps being an integer multiple of the sampling channels.

[0059] According to the technology disclosed in the present invention, the infrared touch frame circuit board includes a main board and a plurality of slave boards, the main board is connected in series with the slave board through a scan data bus and a slave resistor corresponding to the slave board in sequence, and the main board is connected to the slave board through a synchronous scan signal bus. In this way, the main board can determine the address information of the slave board through the slave resistor corresponding to the slave board, and the main board sends corresponding scan data to each slave board through the scan data bus based on the address information of each slave board. Subsequently, the main board can send a synchronous scan signal to each slave board through the synchronous scan signal bus, so that each slave board responds to the synchronous scan signal synchronously, and controls the infrared lamp in the slave board to perform scanning according to the corresponding scan data. Moreover, the connection line between the main board and each slave board is simple, and it is not necessary to occupy too many pins of the main board, so that the scan data can be accurately sent to each slave board, so that the synchronous scan can be realized by sending the synchronous scan signal through only one synchronous scan signal bus in the future.

[0060] 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:

[0061] During initial use, the master MCU will first initialize the complete scan data when it is powered on, and read the address of each online slave MCU through the pull-up resistor of each online slave MCU pulled up to the scan data bus (IIC bus). Then, the scan data is sent to each slave MCU through the scan data bus. The scan data is used to provide the slave MCU with relevant data and related scan logic for controlling infrared emission and reception scanning, and the slave MCU saves the corresponding scan data. When the slave MCU receives the synchronous scan signal from the master MCU, it calls the corresponding scan data to control the infrared transmitting tube of the slave board to transmit or control the infrared receiving tube to perform synchronous scanning. For example, when the production is shipped or the scan data is updated, the master MCU can accurately identify the address of each slave MUC through the pull-up resistor of each slave MCU on the scan data bus, so as to accurately send the corresponding scan data to the corresponding slave MCU.

[0062] In daily use, when the machine is powered on, the master MCU first reads the check value calculated by the slave MCU through the digital signal bus and performs the check. Since the position of the infrared lamp controlled by each slave board is different, its scanning task is also different. Therefore, when the host 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 scanning data is sent 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 according to the scanning data and the synchronous scanning signal.

[0063] For example, each time the power is turned on, the master MCU will verify with the slave MCU through the scan data 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.

[0064] The scanning process is driven by the main MCU, which controls the scanning of each slave MCU through a synchronous scanning signal. The synchronous scanning signal can use a PWM synchronous scanning signal. The slave MCU performs GPIO output according to the PWM synchronous scanning signal and the scanning data, and selects the infrared transmitting tube for transmission or the infrared receiving tube for reception based on this.

[0065] Before scanning begins, the master MCU first performs a check, or issues corresponding scanning data to each slave MCU through the scanning data bus and pull-up resistor. The scanning data includes the position information of the infrared receiving lamp and infrared transmitting lamp connected to the slave MCU, as well as the corresponding scanning logic. After the slave MCU receives the synchronous scanning signal sent by the master MCU, the slave MCU starts scanning control according to the synchronous scanning signal and scanning data, interprets the control information of the synchronous scanning signal, and controls the connected infrared receiving lamp and infrared transmitting lamp to work at the appropriate timing.

[0066] After the scan starts, the master MCU only needs to send a PWM synchronous scan signal to each slave MCU to complete the scan control. The synchronous scan signal has a small amount of data, thereby ensuring the scan speed while ensuring accurate scan control of each slave MCU. For example, after the scan starts, the master MCU does not need to send different scan data and corresponding scan control signals for different scan conditions of each slave MCU, thereby reducing 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.

[0067] For the analysis and processing of PWM synchronous scanning signals, the MCU receives the PWM synchronous scanning 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.

[0068] As in the above-mentioned embodiment, the master MCU is connected to each slave MCU only through an IIC bus and different pull-up resistors. The connection line is simple and does not occupy too many pins of the master MCU, so that the scan data can be accurately distributed to each slave MCU. In this way, subsequently, a synchronous scan signal is sent to each slave MCU through a synchronous scan signal line, and each slave MCU can realize synchronous scanning. The complex scanning purpose is achieved by using a simple control method, with high reliability and fast scanning speed. At the same time, the use of logic devices is reduced, and the function of controlling the scanning state of the transmitting lamp and the receiving lamp on a single slave board can be realized on a single MCU, with high reliability. All slave boards can be driven to perform synchronous scanning through a PWM synchronous scan signal, avoiding complex control logic.

[0069] An embodiment of the infrared touch frame is described below.

[0070] The infrared touch frame provided by the present application mainly includes the infrared touch frame circuit board of any of the above embodiments, and an infrared lamp array connecting the host board and the slave board. Figure 5 As shown, Figure 5 This is a schematic diagram of an infrared touch frame structure of an example, showing a partial structure. In the structure shown in the figure, the infrared lamp tube array includes an infrared transmitting tube array and an infrared receiving tube array, and the infrared transmitting tubes and the infrared receiving tubes are arranged at intervals.

[0071] When in use, the host board can set the slave board connected to one of the slave boards to the receiving state through polling, and set the other slave boards to the transmitting state in turn; adopting the group scanning method, taking the slave board ⑧ as an example, the slave board ⑧ is set to the receiving state, at this time, the top (slave board ④ and slave board ⑤), the left (slave board ⑥ and slave board ⑦) and the right (slave board ② and slave board ③) are set to the transmitting state in turn, and each slave board is respectively connected to k=20 infrared transmitting tubes and k=20 infrared receiving tubes; the corresponding numbers of the infrared receiving tubes are 1 to 20, and the group scanning method is adopted. Use 5 infrared receiving tubes as a group for scanning, then 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 infrared light signals, output 5 analog electrical signals to the analog signal bus and transmit them 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 20 infrared receiving tubes. In this way, the infrared receiving tubes are scanned periodically.

[0072] As in the infrared touch frame of the above-mentioned embodiment, the circuit processing flow is simplified, the response speed is fast, and the frame rate of infrared scanning is improved; through the transmission of scanning data and the synchronous scanning signal control mechanism, the amount of scanning control signal data transmitted between the host board and the slave board during scanning can be avoided to be too large, thereby meeting the requirements of high-speed scanning.

[0073] An embodiment of the infrared touch screen is described below.

[0074] The infrared touch screen provided by this application is Figure 5 As shown, Figure 5 This 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.

[0075] The infrared touch screen in the above-mentioned 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 synchronous scanning signal control mechanism, it can avoid 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.

[0076] The electronic device as in the above embodiment may be various tablet terminals, such as an educational tablet terminal, a conference tablet terminal and other tablet terminals, etc.; since the infrared touch screen of the above embodiment is used, it may have better touch performance.

[0077] 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 those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0078] The above description is only a partial implementation method 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, characterized in that: It includes a main board and a plurality of slave boards, wherein the main board is connected in series with the slave boards through a scan data bus and slave resistors corresponding to the slave boards in sequence, and the main board is connected with the slave boards through a synchronous scan signal bus; The host board is used to determine the address information of the slave board based on the slave resistance corresponding to the slave board, and send the scan data to the slave board through the scan data bus based on the address information; The main board is also used to send a synchronous scanning signal to each of the slave boards through the synchronous scanning signal bus; The slave board is used to receive the scanning data, and when receiving the synchronous scanning signal, controls the infrared lamp in the slave board to perform scanning according to the scanning data; The main board attenuates the synchronous scanning signal first, and then transmits the attenuated synchronous scanning signal to the slave board; the slave board receives the attenuated synchronous scanning signal and amplifies and restores it.

2. The infrared touch frame circuit board according to claim 1, characterized in that: The synchronous scanning signal is a PWM signal; wherein the PWM signal is provided with a synchronous scanning start signal and a PWM pulse signal, and the pulse width of the start signal is different from the pulse width of the PWM pulse signal; The main board is used to send the PWM signal to each slave board, and each slave board is used to receive the PWM signal. Based on the start signal in the PWM signal, each slave board is synchronously triggered to start controlling the infrared transmitting tube in the slave board to transmit signals or control the infrared receiving tube to receive signals based on the PWM pulse signal in the PWM signal and the corresponding scanning data.

3. The infrared touch frame circuit board according to claim 2, characterized in that: A buffer time interval is set between the start signal and the PWM pulse signal.

4. The infrared touch frame circuit board according to claim 1, characterized in that: The host board is used to send the corresponding scanning data to each of the slave boards based on the address information of each of the slave boards, so as to set at least one of the slave boards to a receiving state, and to set other slave boards that are not on the same side as the slave board in the receiving state to a transmitting state.

5. The infrared touch frame circuit board according to claim 4, characterized in that: The receiving state is that at least one infrared receiving tube in the corresponding slave board is in a state where it is allowed to work, and all the infrared transmitting tubes in the corresponding slave board are in a state where it is prohibited to work; The emission state is that all the infrared receiving tubes in the corresponding slave board are in a state of being prohibited from working, and at least one infrared transmitting tube in the corresponding slave board is in a state of being allowed to work.

6. The infrared touch frame circuit board according to claim 1, characterized in that: The slave board is also used to load the touch data obtained by the scanning operation into the scanning data bus, so that the touch data is transmitted to the host board; The main board is further used to calculate the coordinate position of the touch object based on the touch data provided by each of the slave boards.

7. The infrared touch frame circuit board according to claim 1, characterized in that: The main board is used for verifying the scan data with each of the slave boards through the scan data bus based on the address information of each of the slave boards when the main board is powered on; The host board is also used for re-sending the corresponding scanning data to the slave board that failed the verification through the scanning data bus when any of the slave boards fails the verification.

8. The infrared touch frame circuit board according to any one of claims 1 to 7, characterized in that: The slave resistors corresponding to the slave boards are different.

9. An infrared touch frame, characterized in that: include: The infrared touch frame circuit board according to any one of claims 1 to 8, and an infrared lamp array connecting a main board and a plurality of slave boards in the infrared touch frame circuit board.

10. An infrared touch screen, characterized in that: The invention comprises a display screen and the infrared touch frame as claimed in claim 9, wherein the infrared touch frame is arranged around the display screen.

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