阅读说明：本技术 多媒体电子白板超声波信号处理电路 (Ultrasonic signal processing circuit of multimedia electronic whiteboard ) 是由 周隆金 梁小龙 孙国兵 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种多媒体电子白板超声波信号处理电路。所述多媒体电子白板超声波信号处理电路包括：包括发送电路及接收电路；所述发送电路发送超声波控制信号,所述接收电路接收所述超声波控制信号；所述超声波控制信号经所述放大子电路降噪放大,所述峰值检测子电路检测经所述放大子电路降噪放大的超声波控制信号,并提取所述超声波控制信号的最大电压值传给所述控制子电路,所述控制子电路依据所述最大电压值获取对所述超声波的增益补偿量,所述增益补偿子电路依据所述增益补偿量对所述超声波控制信号进行增益补偿。本发明具有定位准确、实时性高及交互性好的优点。(The invention discloses an ultrasonic signal processing circuit of a multimedia electronic whiteboard. The multimedia electronic whiteboard ultrasonic signal processing circuit comprises: comprises a transmitting circuit and a receiving circuit; the transmitting circuit transmits an ultrasonic control signal, and the receiving circuit receives the ultrasonic control signal; the ultrasonic control signal is subjected to noise reduction and amplification through the amplification sub-circuit, the peak detection sub-circuit detects the ultrasonic control signal subjected to noise reduction and amplification through the amplification sub-circuit, the maximum voltage value of the ultrasonic control signal is extracted and transmitted to the control sub-circuit, the control sub-circuit obtains the gain compensation amount of the ultrasonic wave according to the maximum voltage value, and the gain compensation sub-circuit performs gain compensation on the ultrasonic control signal according to the gain compensation amount. The invention has the advantages of accurate positioning, high real-time performance and good interactivity.)

1. The ultrasonic signal processing circuit of the multimedia electronic whiteboard is characterized by comprising a sending circuit and a receiving circuit; the transmitting circuit transmits an ultrasonic control signal, and the receiving circuit receives the ultrasonic control signal; the receiving circuit comprises a receiving probe, a control sub-circuit, an amplification sub-circuit, a peak value detection sub-circuit and a gain compensation sub-circuit; the receiving probe is electrically connected with the amplifying sub-circuit; the receiving probe, the amplifying sub-circuit, the peak detection sub-circuit and the gain compensation sub-circuit are respectively electrically connected with the control sub-circuit; the ultrasonic control signal is subjected to noise reduction and amplification through the amplification sub-circuit, the peak detection sub-circuit detects the ultrasonic control signal subjected to noise reduction and amplification through the amplification sub-circuit, the maximum voltage value of the ultrasonic control signal is extracted and transmitted to the control sub-circuit, the control sub-circuit obtains the gain compensation amount of the ultrasonic wave according to the maximum voltage value, and the gain compensation sub-circuit performs gain compensation on the ultrasonic control signal according to the gain compensation amount.

2. The ultrasonic signal processing circuit of the multimedia electronic whiteboard of claim 1, wherein the peak detection sub-circuit comprises a first operational amplifier, a second operational amplifier, a first capacitor, a first diode and a first resistor; the positive input end of the first operational amplifier is electrically connected with the amplification sub-circuit, the negative input end of the first operational amplifier is electrically connected with the first end of the first diode, the first end of the first resistor, the positive input end of the second operational amplifier and the first end of the first capacitor, the output end of the first operational amplifier is electrically connected with the second end of the first diode, the second end of the first resistor is grounded, the second end of the first capacitor is grounded, the negative input end of the second operational amplifier is electrically connected with the output end of the second operational amplifier, and the output end of the second operational amplifier is electrically connected with the control sub-circuit.

3. The multimedia electronic whiteboard ultrasonic signal processing circuit according to claim 1 or 2, wherein the amplifying sub-circuit comprises a first amplifying unit and a second amplifying unit; the first amplification unit is used for carrying out primary amplification on the ultrasonic control signal, and the second amplification unit is used for carrying out secondary amplification on the ultrasonic control signal.

4. The multimedia electronic whiteboard ultrasonic signal processing circuit according to claim 3, wherein the gain compensation circuit comprises a digital potentiometer, a gain controlled amplifying unit and a control voltage forming unit; the digital potentiometer is electrically connected with the gain controlled amplifying unit, and the gain controlled amplifying unit is electrically connected with the control voltage forming unit.

5. The multimedia electronic whiteboard ultrasonic signal processing circuit of claim 4, wherein the receiving circuit further comprises a temperature compensation sub-circuit; the temperature compensation sub-circuit is electrically connected with the control sub-circuit.

6. The multimedia electronic whiteboard ultrasonic signal processing circuit of claim 5, wherein the gain-controlled amplifying unit comprises a third amplifier and a fourth amplifier, a second capacitor, a second resistor and a third resistor; the positive input end of the third amplifier is electrically connected with the peak detection sub-circuit, the negative input end of the third amplifier is electrically connected with the first end of the second capacitor, the second end of the second capacitor is electrically connected with the output end of the third amplifier and the first end of the second resistor, the second end of the second resistor is electrically connected with the negative input end of the fourth amplifier and the first end of the third resistor, the second end of the third resistor is electrically connected with the output end of the third amplifier, and the positive input end of the fourth amplifier is electrically connected with the control sub-circuit.

7. The multimedia electronic whiteboard ultrasonic signal processing circuit of claim 6, wherein the digital potentiometer is a dual-channel digital potentiometer.

8. The multimedia electronic whiteboard ultrasonic signal processing circuit of claim 6, wherein the temperature compensation sub-circuit comprises a temperature sensor and a fourth resistor; the first end of the temperature sensor is electrically connected with the first end of the fourth resistor, the second end of the temperature sensor is electrically connected with the second end of the fourth resistor and the control sub-circuit, and the third end of the temperature sensor is grounded.

9. A method, characterized in that the multimedia electronic whiteboard ultrasonic signal processing circuit of claim 8, the method comprising:

sending an ultrasonic control signal;

receiving the ultrasonic control signal;

carrying out noise reduction and amplification on the ultrasonic control signal;

extracting a maximum voltage value according to the ultrasonic control signal subjected to noise reduction and amplification;

acquiring a distance value between the signal pen and the ultrasonic receiving head according to the maximum voltage value;

acquiring gain compensation quantity of the ultrasonic control signal according to the distance value;

and performing gain compensation on the ultrasonic control signal according to the gain compensation amount.

Technical Field

The invention relates to the technical field of electronic whiteboards, in particular to a multimedia electronic whiteboard ultrasonic signal processing circuit.

Background

In the technical field of electronic whiteboards, an interactive electronic whiteboard is an electronic product which has strong interactivity and can write, project, operate a computer and record writing contents, the interactive electronic whiteboard can replace the traditional blackboard and projection screen, and a wide screen display technology and an electronic whiteboard control technology are combined to form novel computer interactive input and output equipment, so that the interactive electronic whiteboard is particularly suitable for teaching and office meetings and has strong interactivity. With the development of network technology, interactive electronic whiteboards are developing towards multifunction, remote monitoring, intellectualization, ultra-wide screen and precision.

However, the interactive electronic whiteboard in the prior art still has the defects of inaccurate positioning and low real-time performance. Therefore, the invention provides an interactive electronic whiteboard processing circuit with accurate positioning and high real-time performance, which is a problem to be solved urgently by the technical personnel in the field.

Disclosure of Invention

The invention solves the technical problem of providing an interactive multimedia electronic whiteboard ultrasonic signal processing circuit which can accurately position and has high real-time performance.

In one aspect, the present invention discloses a multimedia electronic whiteboard ultrasonic signal processing circuit, including: a transmission circuit and a reception circuit; the transmitting circuit transmits an ultrasonic control signal, and the receiving circuit receives the ultrasonic control signal; the receiving circuit comprises a receiving probe, a control sub-circuit, an amplification sub-circuit, a peak value detection sub-circuit and a gain compensation sub-circuit; the receiving probe, the amplifying sub-circuit, the peak detection sub-circuit and the gain compensation sub-circuit are respectively electrically connected with the control sub-circuit; the receiving probe is electrically connected with the amplifying sub-circuit; the ultrasonic control signal is subjected to noise reduction and amplification through the amplification sub-circuit, the peak detection sub-circuit detects the ultrasonic control signal subjected to noise reduction and amplification through the amplification sub-circuit, the maximum voltage value of the ultrasonic control signal is extracted and transmitted to the control sub-circuit, the control sub-circuit obtains the gain compensation amount of the ultrasonic wave according to the maximum voltage value, and the gain compensation sub-circuit performs gain compensation on the ultrasonic control signal according to the gain compensation amount.

Preferably, the peak detection sub-circuit comprises a first operational amplifier, a second operational amplifier, a first capacitor, a first diode and a first resistor; the positive input end of the first operational amplifier is electrically connected with the amplification sub-circuit, the negative input end of the first operational amplifier is electrically connected with the first end of the first diode, the first end of the first resistor, the positive input end of the second operational amplifier and the first end of the first capacitor, the output end of the first operational amplifier is electrically connected with the second end of the first diode, the second end of the first resistor is grounded, the second end of the first capacitor is grounded, the negative input end of the second operational amplifier is electrically connected with the output end of the second operational amplifier, and the output end of the second operational amplifier is electrically connected with the control sub-circuit.

Preferably, the amplifying sub-circuit comprises a first amplifying unit and a second amplifying unit; the first amplification unit is used for carrying out primary amplification on the ultrasonic control signal, and the second amplification unit is used for carrying out secondary amplification on the ultrasonic control signal.

Preferably, the gain compensation circuit comprises a digital potentiometer, a gain controlled amplification unit and a control voltage forming unit; the digital potentiometer is electrically connected with the gain controlled amplifying unit, and the gain controlled amplifying unit is electrically connected with the control voltage forming unit.

Preferably, the receiving circuit further comprises a temperature compensation sub-circuit; the temperature compensation sub-circuit is electrically connected with the control sub-circuit.

Preferably, the gain-controlled amplifying unit includes a third amplifier and a fourth amplifier, a second capacitor, a second resistor and a third resistor; the positive input end of the third amplifier is electrically connected with the peak detection sub-circuit, the negative input end of the third amplifier is electrically connected with the first end of the second capacitor, the second end of the second capacitor is electrically connected with the output end of the third amplifier and the first end of the second resistor, the second end of the second resistor is electrically connected with the negative input end of the fourth amplifier and the first end of the third resistor, the second end of the third resistor is electrically connected with the output end of the third amplifier, and the positive input end of the fourth amplifier is electrically connected with the control sub-circuit.

Preferably, the digital potentiometer is a dual-channel digital potentiometer.

Preferably, the temperature compensation sub-circuit comprises a temperature sensor and a fourth resistor; the first end of the temperature sensor is electrically connected with the first end of the fourth resistor, the second end of the temperature sensor is electrically connected with the second end of the fourth resistor and the control sub-circuit, and the third end of the temperature sensor is grounded.

On the other hand, the invention also discloses a method which comprises a multimedia electronic whiteboard ultrasonic signal processing circuit used for improving the real-time performance and the positioning accuracy, and the method comprises the following steps:

sending an ultrasonic control signal;

receiving the ultrasonic control signal;

carrying out noise reduction and amplification on the ultrasonic control signal;

extracting a maximum voltage value according to the ultrasonic control signal subjected to noise reduction and amplification;

acquiring a distance value between the signal pen and the ultrasonic receiving head according to the maximum voltage value;

acquiring gain compensation quantity of the ultrasonic control signal according to the distance value;

and performing gain compensation on the ultrasonic control signal according to the gain compensation amount.

The ultrasonic signal processing circuit of the multimedia electronic whiteboard has the following beneficial effects: the multimedia electronic whiteboard ultrasonic signal processing circuit comprises a sending circuit and a receiving circuit; the transmitting circuit transmits an ultrasonic control signal, and the receiving circuit receives the ultrasonic control signal; the receiving circuit comprises a receiving probe, a control sub-circuit, an amplification sub-circuit, a peak value detection sub-circuit and a gain compensation sub-circuit; the receiving probe is electrically connected with the amplifying sub-circuit; the receiving probe, the amplifying sub-circuit, the peak detection sub-circuit and the gain compensation sub-circuit are respectively electrically connected with the control sub-circuit; the receiving probe receives the ultrasonic signal, and the ultrasonic control signal is subjected to noise reduction and amplification by the amplification sub-circuit, so that clutter is reduced, and the control accuracy is improved; the peak detection sub-circuit detects the ultrasonic control signal subjected to noise reduction and amplification by the amplification sub-circuit, extracts the maximum voltage value of the ultrasonic control signal and transmits the maximum voltage value to the control sub-circuit, the control sub-circuit obtains the gain compensation amount of the ultrasonic wave according to the maximum voltage value, and the gain compensation sub-circuit performs gain compensation on the ultrasonic control signal according to the gain compensation amount. Therefore, the ultrasonic control signal of the shaping circuit is kept unchanged, the error is reduced, and the positioning accuracy and the real-time performance are improved. Therefore, the invention has the advantages of accurate positioning, high real-time performance and good interactivity.

Drawings

Fig. 1 is a schematic block diagram of an ultrasonic signal processing circuit of a multimedia electronic whiteboard according to an embodiment of the present invention.

Fig. 2 is a circuit diagram of a peak detection sub-circuit of the multimedia electronic whiteboard ultrasonic signal processing circuit according to the embodiment of the present invention.

Fig. 3 is a circuit diagram of an amplifying sub-circuit of the multimedia electronic whiteboard ultrasonic signal processing circuit according to the embodiment of the present invention.

Fig. 4 is a circuit diagram of a gain-controlled amplifying sub-circuit of the multimedia electronic whiteboard ultrasonic signal processing circuit according to the embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples. It should be noted that, if not conflicting, the embodiments of the present invention and the features of the embodiments may be combined with each other within the scope of protection of the present invention.