Infrared touch frame and infrared touch screen

Abstract

The present application relates to an infrared touch frame and an infrared touch screen. The infrared touch frame comprises a master board and a plurality of slave boards, wherein the master board is in cascade connection with the slave boards by means of a connecting line, the master board is connected to the slave boards by means of a digital signal bus, and the master board is connected to the slave boards by means of an analog signal bus. A signal attenuation circuit is provided on the master board, and a signal restoration circuit is provided on each slave board, wherein the signal attenuation circuit is connected to the signal restoration circuit by means of the digital signal bus. The master board outputs a strong digital signal to the signal attenuation circuit for attenuation and transmits, by means of the digital signal bus, the strong digital signal to the signal restoration circuit on the slave board for restoration to a strong digital signal for use; and the slave boards transmit, by means of the analog signal bus, weak analog signals back to the master board for centralized processing. By means of the technical solution, the interference of strong digital signals on weak analog signals is reduced, the complexity of processing an analog signal by means of each slave board is reduced, the response speed is high, and the performance of an infrared touch frame is improved.

Description

Infrared touch frame and infrared touch screen Technical Field

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

[0002] In some circuit boards, it is often necessary to connect with other circuit boards. Signals of different strengths are transmitted and processed between circuit boards. These signals of different strengths may overlap in timing on the same circuit board or connecting line. Weak signals are easily interfered with by strong signals. Since this cannot be avoided in timing, it directly affects the quality of weak signals, causing them to contain interference signal components, which can easily affect the performance of the circuit board.

[0003] In an infrared touch frame, positioning is achieved by emitting and receiving infrared light signals through multiple sets of infrared diodes arranged on circuit boards distributed around the frame. Since infrared light signals are weak analog signals, while the control signals for scanning the infrared lights in the touch frame are strong digital signals, the data packets after A / D sampling of the infrared light signals on the circuit boards and signal buses of the infrared touch frame contain interference signal components from the control signals. This affects the quality of A / D sampling and thus the performance of the infrared touch frame.

[0004] Utility Model Content

[0005] The purpose of this application is to address one of the aforementioned technical deficiencies by providing an infrared touch frame and an infrared touch screen, thereby reducing interference from control signals on the sampling signals of infrared light signals and improving the performance of the infrared touch frame circuit board.

[0006] An infrared touch frame includes a main board and multiple slave boards, wherein the main board and each slave board are cascaded together via connecting cables; the main board and slave boards are connected via a digital signal bus, and the main board and slave boards are also connected via an analog signal bus.

[0007] The main board is equipped with a signal attenuation circuit, and the slave board is equipped with a signal restoration circuit; the signal attenuation circuit and the signal restoration circuit are connected through a digital signal bus.

[0008] The main board outputs a strong digital signal to the signal attenuation circuit for attenuation, and then transmits it to the signal restoration circuit on the slave board through the digital signal bus to restore it into a strong digital signal before use.

[0009] The slave board transmits weak analog signals back to the host board via the analog signal bus for centralized processing.

[0010] An infrared touchscreen includes: a display screen and an infrared touch frame; wherein the infrared touch frame surrounds the display screen.

[0011] The technical solution of this application has the following beneficial effects:

[0012] (1) The strong digital signal is first attenuated into a weak analog signal for transmission, thereby reducing the intersection of the strong digital signal and the weak analog signal on the transmission line, thus reducing the interference of the strong digital signal on the weak analog signal.

[0013] (2) Each slave board sends the analog signal back to the host board and then performs the touch positioning process in a centralized manner. This simplifies the processing flow of infrared light signals on the slave board, reduces the complexity of processing analog signals on each slave board, increases the response speed, improves the frame rate of infrared scanning, and enhances the performance of the infrared touch frame.

[0014] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0015] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0016] Figure 1 is a structural block diagram of an infrared touch frame according to an embodiment;

[0017] Figure 2 is a schematic diagram of the circuit board structure of an infrared touch frame according to an embodiment;

[0018] Figure 3 is a circuit diagram of the main board and slave board in one embodiment;

[0019] Figure 4 is a structural block diagram of an infrared touch frame according to another embodiment;

[0020] Figure 5 is a circuit diagram of the main board and slave board in another embodiment;

[0021] Figure 6 is a schematic diagram of an example PWM synchronization signal. Detailed Implementation

[0022] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0023] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in this application’s specification means the presence of the stated feature, integer, step, or operation, but does not preclude the presence or addition of one or more other features, integers, steps, or operations.

[0024] In the infrared touch frame, the analog electrical signal converted from the infrared light signal is a weak analog signal, while the control signal that controls the infrared light in the touch frame to scan is a strong digital signal. The weak analog signal and the strong digital signal exist on the same circuit board or analog signal bus and have overlapping timing, which leads to signal crosstalk and affects the sampling quality of the infrared light signal.

[0025] Accordingly, this application provides an infrared touch frame, as shown in Figure 1. Figure 1 is a structural block diagram of an embodiment of an infrared touch frame, including a main board and multiple slave boards. The main board and each slave board are cascaded together via connecting lines and connected via a signal bus, which includes a digital signal bus and an analog signal line connection. As shown in Figure 1, the infrared touch frame includes slave boards ① to ⑧, wherein the slave boards are connected to infrared lamps; the main board and the slave boards are connected by a digital signal bus and an analog signal bus, and each slave board shares the analog signal bus. The main board can be connected to the slave boards as a separate circuit board, or it can be integrated into any slave board and share a circuit board card with the slave boards. In the example shown in the figure, the main board is integrated on slave board ⑧. If the main board is a separate circuit board card, no infrared lamps are provided on the main board.

[0026] In a specific implementation, the slave board may include a receiver board and a transmitter board; the transmitter board is connected to an infrared emitting tube, and the receiver board is connected to an infrared receiving tube. The master board is connected to the receiver board and the transmitter board through a digital signal bus, and the master board is connected to each receiver board through an analog signal bus.

[0027] Referring to Figure 2, which is a schematic diagram of the circuit board structure of an infrared touch frame according to an embodiment, the main board and slave boards 1 to n (n≥2) are cascaded. The main board is provided with a signal attenuation circuit, and the slave boards are provided with a signal restoration circuit. The signal attenuation circuit and the signal restoration circuit are connected through a digital signal bus. For example, the signal attenuation circuit may include a passive attenuation circuit or an active attenuation circuit; the signal restoration circuit may include a non-inverting amplifier circuit, an inverting amplifier circuit, a transistor amplifier circuit, or a comparator circuit, etc.

[0028] In the application, the motherboard outputs a strong digital signal to the signal attenuation circuit for attenuation, and then transmits it to the signal restoration circuit on the slave board via the digital signal bus to restore it to a strong digital signal for use. For example, the strong digital signal can be the control signal for the motherboard to control the infrared lamps on the slave board to scan. Specifically, the signal attenuation circuit attenuates the strong digital signal by N times to obtain an attenuated digital signal, which is transmitted to the slave board via the digital signal bus. The signal restoration circuit amplifies the attenuated digital signal by M times to obtain a strong digital signal that can be used by the slave board.

[0029] The technical solution of the above embodiment is applicable to situations where strong digital signals and weak analog signals coexist in the infrared touch frame circuit board and signal bus. On the same circuit board or signal bus, weak analog signals are easily interfered with by strong digital signals, causing the weak analog signals to contain interference signal components when performing AD sampling. In this embodiment, the infrared touch frame first attenuates the signal strength of the strong digital signal and then restores it during use, avoiding the influence of the control signal on the sampling quality of the weak analog signal when it is transmitted on the circuit board or signal bus, thus improving the stability of the infrared touch frame.

[0030] In practice, the aforementioned weak analog signal can be an analog electrical signal. The infrared receiving tube connected to the receiving board receives the infrared light signal emitted by the infrared emitting tube and converts the infrared light signal into an analog electrical signal. The receiving board then transmits the analog electrical signal back to the host board for centralized processing via the analog signal bus.

[0031] As in the above embodiment, each receiving board shares an analog signal bus. Each receiving board converts the collected infrared light signal into a weak analog signal and directly loads it onto the analog signal bus to be sent back to the host board for centralized amplification and A / D sampling processing. This reduces the need for amplification and digital signal conversion processing circuits on the slave board, reduces the complexity of the slave board's circuit structure, improves response speed, and increases the frame rate of infrared scanning.

[0032] In one embodiment, the structure of the main board and slave board of the infrared touch frame is shown in Figure 3. Figure 3 is a circuit structure diagram of the main board and slave board of an embodiment. The figure shows some circuit components. The main board is connected in sequence to a signal conditioning circuit, an A / D sampling circuit, a main MCU (Microprocessor Control Unit), and a signal attenuation circuit. The signal conditioning circuit is connected to the analog signal bus, and the main MCU is connected to the digital signal bus through the signal attenuation circuit. The transmitter board and receiver board are provided with a slave MCU and a signal restoration circuit. The slave MCU is connected to the digital signal bus through the signal restoration circuit.

[0033] For example, an analog signal bus can include multiple parallel signal channels. When the infrared receiver tubes use a group scanning method, since multiple infrared receiver tubes output analog electrical signals at the same time, each signal channel can simultaneously transmit the analog signals to the host board. The slave MCU can control the connected infrared transmitters and receivers to perform scanning operations. Data transmission between the master MCU and the slave MCU is based on address recognition, and each slave board is configured with a hardware address.

[0034] Before scanning begins, the main MCU on the motherboard sends the scan data, which serves as the control signal, to the slave MCUs on each slave board via the digital signal bus. Each slave MCU receives and stores its own scan data. When the receiving MCU on each slave board performs the scanning of the infrared lamps, it reads the scan data and performs the scanning based on the scan data.

[0035] The scanning data mainly includes the position information of the infrared receiver connected to the receiver board and the infrared transmitter connected to the transmitter board, as well as the corresponding scanning logic.

[0036] After scanning begins, the infrared receiver tube on the receiving board receives the infrared light signal, converts it into an analog signal, loads it onto the analog signal bus, and aggregates it onto the main board. The signal conditioning circuit on the main board detects the analog signal from the analog signal bus and amplifies and conditions it. The A / D sampling circuit performs A / D sampling on the amplified analog signal to obtain a digital signal, which is then sent back to the main MCU. The main MCU analyzes and processes the digital signal to calculate the coordinate position of the touched object, or uploads it to the host computer, etc.

[0037] In one embodiment, as shown in Figure 4, which is a structural block diagram of an infrared touch frame according to another embodiment, only the circuit parts related to the embodiment are shown in the figure. In the infrared touch frame, the host board and multiple slave boards include a digital signal bus, an analog signal bus, and a synchronization signal bus. The synchronization signal bus is connected between the signal attenuation circuit of the host board and the signal restoration circuit of the slave board, and is used by the host board to transmit a synchronization signal that triggers infrared scanning to the slave board.

[0038] In this embodiment, the main board transmits the synchronization signal controlling the infrared lamp to the slave board through the synchronization signal bus, so as to trigger the slave board to scan the infrared lamp.

[0039] As shown in Figure 5, which is a circuit structure diagram of the main board and slave board in another embodiment, only the circuit parts related to the embodiment are shown in the figure. Specifically, the main board controls the infrared lamps of the receiving board to perform scanning through a synchronization signal. After the main MCU sends the scanning data to the slave MCUs of each slave board for storage, each slave MCU waits for the synchronization signal sent by the main MCU. When the slave MCU of the transmitting board receives the synchronization signal, it parses the synchronization signal and controls the infrared emitting tube to emit infrared light signals according to the scanning data. When the slave MCU of the receiving board receives the synchronization signal, it parses the synchronization signal and controls the infrared receiving tube to scan according to the scanning data. When sending the synchronization signal, the synchronization signal is first attenuated by a signal attenuation circuit and then restored by a signal restoration circuit.

[0040] In one embodiment, the synchronization signal used by the motherboard can be a PWM synchronization signal; the PWM synchronization signal includes a start signal for synchronous scanning and a PWM pulse signal; referring to Figure 6, which is a schematic diagram of an example PWM synchronization signal, the pulse width of the start signal is different from the PWM pulse width of the light switch. As shown in the figure, the pulse width of the start signal is τ1, the PWM pulse width of the light switch is τ2, and the time interval between them is τ3. The time interval τ3 is used as a buffer time to wait for the slave board to complete the start signal parsing and the scan data preparation, thereby facilitating the synchronous start scan control of each slave host; where τ1, τ2, and τ3 are set time widths, for example, τ1 = 4us, τ2 = 0.5us, and τ3 = 59.35us; after the motherboard transmits the PWM synchronization signal to the slave host, the slave host parses the data of the PWM synchronization signal in real time and starts a frame scan when the start signal is detected.

[0041] As in the above embodiment, a single PWM synchronization signal can drive all slave boards to perform synchronous scanning, avoiding complex control logic.

[0042] The following describes an embodiment of an infrared touchscreen.

[0043] The infrared touchscreen of this embodiment includes a display screen and an infrared touch frame; the infrared touch frame surrounds the display screen. As in the infrared touchscreen of the above embodiment, the infrared touch frame of the aforementioned embodiment attenuates strong digital signals into weak analog signals before transmission, thereby reducing the intersection of strong digital signals and weak analog signals on the transmission line, thus reducing interference between strong digital signals and weak analog signals. Each slave board sends analog signals back to the master board for centralized touch positioning processing, simplifying the processing flow of infrared light signals on the slave boards, reducing the complexity of analog signal processing on each slave board, resulting in faster response speed, improved infrared scanning frame rate, and enhanced performance of the infrared touch frame.

[0044] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0045] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An infrared touch frame, comprising a main board and multiple slave boards, wherein the main board and each slave board are cascaded via connecting cables; characterized in that, The main board and the slave board are connected via a digital signal bus, and the main board and the slave board are connected via an analog signal bus. The host board is equipped with a signal attenuation circuit, and the slave board is equipped with a signal restoration circuit; The signal attenuation circuit and the signal restoration circuit are connected via a digital signal bus; The main board outputs a strong digital signal to the signal attenuation circuit for attenuation, and then transmits it to the signal restoration circuit on the slave board through the digital signal bus to restore it into a strong digital signal before use. The slave board transmits weak analog signals back to the host board via the analog signal bus for centralized processing.

2. The infrared touch frame according to claim 1, characterized in that, The strong digital signal is the control signal of the main board to control the infrared lamps of the slave board to scan, and the weak analog signal is the analog electrical signal converted from the infrared light signal collected by the slave board.

3. The infrared touch frame according to claim 1, characterized in that, The motherboard also includes a signal conditioning circuit, an A / D sampling circuit, and a main MCU connected in sequence; wherein, the signal conditioning circuit is connected to the analog signal bus, and the main MCU is connected to the digital signal bus through a signal attenuation circuit.

4. The infrared touch frame according to claim 3, characterized in that, The slave board is also equipped with a slave MCU; wherein the slave MCU is connected to the digital signal bus through a signal restoration circuit.

5. The infrared touch frame according to claim 1, characterized in that, The signal attenuation circuit includes a passive attenuation circuit or an active attenuation circuit; the signal restoration circuit includes a non-inverting amplifier circuit, an inverting amplifier circuit, a transistor amplifier circuit, or a comparator circuit.

6. The infrared touch frame according to claim 1, characterized in that, The slave board includes a receiver board and a transmitter board; wherein, the master board is connected to each receiver board and transmitter board via a digital signal bus, and the master board is connected to each receiver board via an analog signal bus.

7. The infrared touch frame according to any one of claims 1 to 6, characterized in that, The signal bus also includes a synchronization signal bus connected between the signal attenuation circuit of the main board and the signal restoration circuit of the slave board, used by the main board to transmit a synchronization signal that triggers infrared scanning to the slave board.

8. The infrared touch frame according to claim 7, characterized in that, The main board transmits the synchronization signal controlling the infrared lamp to the slave board through the synchronization signal bus, thereby triggering the slave board to scan the infrared lamp.

9. The infrared touch frame according to claim 8, characterized in that, The synchronization signal is a PWM synchronization signal; wherein, the PWM synchronization signal includes a start signal for synchronous scanning and a PWM pulse signal.

10. An infrared touchscreen, characterized in that, include: The display screen and the infrared touch frame as described in claim 9; wherein the infrared touch frame is disposed around the display screen.

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