Method and circuit for improving light resistance of infrared touch frame

Abstract

The invention discloses a method and circuit for improving the light resistance of an infrared touch frame, the circuit comprises a D1, an R1, a Q1, a Q2 and a C1, the negative electrode of the D1 is electrically connected to a Vcc1, one end of the R1 is electrically connected to the Vcc1, the other end of the R1 is electrically connected to the positive electrode of the D1, the b electrode of the Q1 is electrically connected to the positive electrode of the D1, the c electrode of the Q1 is electrically connected to a Vcc2, the D electrode of the Q2 is electrically connected to the e electrode of the Q1, the S electrode of the Q2 is grounded, and the C1 is grounded. And one end of the C1 is electrically connected to the e pole of the Q1. The invention relates to the field of improving the light resistance of an infrared touch frame, in particular to a method and circuit for improving the light resistance of the infrared touch frame.

Description

Technical Field

[0001] The present invention relates to the field of improving the light resistance of an infrared touch frame, and in particular to a method and a circuit for improving the light resistance of an infrared touch frame. Background Art

[0002] The infrared touch frame is a touch device that uses infrared touch sensing technology. The infrared touch frame forms an infrared detection network on the screen surface through infrared emitting and receiving sensing elements. When an object touches the screen, it will change the infrared on the contact point, which is converted into the touch coordinate position to achieve operation response.

[0003] In the infrared touch frame, the infrared receiving tube can receive both the infrared light emitted by the infrared transmitting tube and the external ambient light. The interference signal caused by the ambient light will seriously affect the performance of the infrared touch frame. Figure 1 shown.

[0004] At present, the method for processing the light interference of the infrared touch frame is to treat the ambient light as a DC signal and filter out the ambient light interference by means of capacitor isolation. This method effectively filters out the ambient light interference to a certain extent and suppresses the amplification of the effective infrared signal to a great extent, because the anti-light circuit is generally in the front-stage amplifier circuit, and the front-stage input signal is very weak. If the amplification factor is too small, it is not conducive to the extraction of the rear-stage signal. If the front-stage amplification factor is too large, it is difficult to adapt to various intensities of ambient light, and the effective signal is easily submerged by the ambient light signal.

[0005] In the original circuit, the size of the first-level signal AIN0 is not only affected by the intensity of the induced light, but also greatly affected by the resistor R2. As an emitter-follower circuit, it mainly plays the role of current amplification and current-to-voltage conversion. Summary of the invention

[0006] The technical problem to be solved by the present invention is that generally the anti-light circuit is in the front-stage amplifier circuit, and the front-stage input signal is very weak. If the amplification factor is too small, it is not conducive to the extraction of the rear-stage signal. If the front-stage amplification factor is too large, it is difficult to adapt to various intensities of ambient light, and the effective signal is easily submerged by the ambient light signal.

[0007] To solve the above problems, the technical solution adopted by the present invention is as follows: The present invention is a circuit for improving the light resistance of an infrared touch frame, comprising D1, R1, Q1, Q2 and C1, the cathode of D1 is electrically connected to Vcc1, one end of R1 is electrically connected to Vcc1, the other end of R1 is electrically connected to the anode of D1, the b pole of Q1 is electrically connected to the anode of D1, the c pole of Q1 is electrically connected to Vcc2, the D pole of Q2 is electrically connected to the e pole of Q1, the S pole of Q2 is grounded, and one end of C1 is electrically connected to the e pole of Q1.

[0008] Furthermore, the G pole of Q2 inputs a DAC signal.

[0009] Furthermore, Q2 is selected from MOSFET or triode.

[0010] Furthermore, a resistor may be connected in series between the D pole of Q2 and the e pole of Q1.

[0011] The present invention is a method for improving the light resistance of an infrared touch frame, comprising the following steps:

[0012] Step 1: Vcc1 and Vcc2 are powered on to provide power to D1, R1 and Q1;

[0013] Step 2: The G pole of Q2 is connected to the external control DAC signal;

[0014] Step 3, by controlling and adjusting the conduction voltage drop of Q2, the gain of the first-stage current signal is adjusted;

[0015] Step 4. Since the controller will continuously collect signal conditions, the software can judge the current ambient light status through the signal conditions, such as strong light, normal light, and weak light. According to different lighting conditions, it outputs the appropriate DAC value and controls the pre-stage amplification factor, thereby improving the adaptability of the entire system to ambient light.

[0016] The beneficial effects achieved by the present invention using the above structure are as follows: the original front-stage anti-light circuit is not adjustable by firmware, and cannot be adaptively adjusted according to various ambient light conditions, which will greatly affect the performance. The present design adaptively filters out ambient light, greatly improves the anti-light performance of the infrared touch frame, and reduces the impact of ambient light on the infrared touch frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the existing infrared signal anti-light method;

[0018] Figure 2 A circuit diagram of embodiment 1 of the present invention is provided;

[0019] Figure 3 A circuit diagram of Embodiment 2 of the present invention is provided;

[0020] Figure 4 The circuit diagram of Embodiment 3 of the present invention is proposed. DETAILED DESCRIPTION

[0021] Example 1

[0022] As the instruction manual Figure 2As shown, the present invention is a circuit for improving the light resistance of an infrared touch frame, comprising D1, R1, Q1, Q2 and C1, the cathode of D1 is electrically connected to Vcc1, one end of R1 is electrically connected to Vcc1, the other end of R1 is electrically connected to the anode of D1, the b pole of Q1 is electrically connected to the anode of D1, the c pole of Q1 is electrically connected to Vcc2, the D pole of Q2 is electrically connected to the e pole of Q1, the S pole of Q2 is grounded, and one end of C1 is electrically connected to the e pole of Q1.

[0023] The G pole of Q2 inputs the DAC signal. Q2 uses MOSFET.

[0024] The present invention is a method for improving the light resistance of an infrared touch frame, comprising the following steps:

[0025] Step 1: Vcc1 and Vcc2 are powered on to provide power to D1, R1 and Q1;

[0026] Step 2: The G pole of Q2 is connected to the external control DAC signal;

[0027] Step 3, by controlling and adjusting the conduction voltage drop of Q2, the gain of the first-stage current signal is adjusted;

[0028] Step 4. Since the controller will continuously collect signal conditions, the software can judge the current ambient light status through the signal conditions, such as strong light, normal light, and weak light. According to different lighting conditions, it outputs the appropriate DAC value and controls the pre-stage amplification factor, thereby improving the adaptability of the entire system to ambient light.

[0029] Example 2

[0030] As the instruction manual Figure 3 As shown, the present invention is a circuit for improving the light resistance of an infrared touch frame, comprising D1, R1, Q1, Q2 and C1, the cathode of D1 is electrically connected to Vcc1, one end of R1 is electrically connected to Vcc1, the other end of R1 is electrically connected to the anode of D1, the b pole of Q1 is electrically connected to the anode of D1, the c pole of Q1 is electrically connected to Vcc2, the D pole of Q2 is electrically connected to the e pole of Q1, the S pole of Q2 is grounded, and one end of C1 is electrically connected to the e pole of Q1.

[0031] The G pole of Q2 inputs the DAC signal. Q2 uses MOSFET. A resistor R2 is connected in series between the D pole of Q2 and the e pole of Q1.

[0032] The present invention is a method for improving the light resistance of an infrared touch frame, comprising the following steps:

[0033] Step 1: Vcc1 and Vcc2 are powered on to provide power to D1, R1 and Q1;

[0034] Step 2: The G pole of Q2 is connected to the external control DAC signal;

[0035] Step 3, by controlling and adjusting the conduction voltage drop of Q2, the gain of the first-stage current signal is adjusted;

[0036] Step 4. Since the controller will continuously collect signal conditions, the software can judge the current ambient light status through the signal conditions, such as strong light, normal light, and weak light. According to different lighting conditions, it outputs the appropriate DAC value and controls the pre-stage amplification factor, thereby improving the adaptability of the entire system to ambient light.

[0037] Example 3

[0038] As the instruction manual Figure 4 As shown, the present invention is a circuit for improving the light resistance of an infrared touch frame, comprising D1, R1, Q1, Q2 and C1, the cathode of D1 is electrically connected to Vcc1, one end of R1 is electrically connected to Vcc1, the other end of R1 is electrically connected to the anode of D1, the b pole of Q1 is electrically connected to the anode of D1, the c pole of Q1 is electrically connected to Vcc2, the c pole of Q2 is electrically connected to the e pole of Q1, the e pole of Q2 is grounded, and one end of C1 is electrically connected to the e pole of Q1.

[0039] The b-pole of Q2 inputs the DAC signal. Q2 uses a triode.

[0040] The present invention is a method for improving the light resistance of an infrared touch frame, comprising the following steps:

[0041] Step 1: Vcc1 and Vcc2 are powered on to provide power to D1, R1 and Q1;

[0042] Step 2: The b-pole of Q2 is connected to the external control DAC signal;

[0043] Step 3, by controlling and adjusting the conduction voltage drop of Q2, the gain of the first-stage current signal is adjusted;

[0044] Step 4. Since the controller will continuously collect signal conditions, the software can judge the current ambient light status through the signal conditions, such as strong light, normal light, and weak light. According to different lighting conditions, it outputs the appropriate DAC value and controls the pre-stage amplification factor, thereby improving the adaptability of the entire system to ambient light.

[0045] It should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A circuit for improving the light resistance of an infrared touch frame, characterized in that: It includes D1, R1, Q1, Q2 and C1, the negative pole of D1 is electrically connected to Vcc1, one end of R1 is electrically connected to Vcc1, the other end of R1 is electrically connected to the positive pole of D1, the b pole of Q1 is electrically connected to the positive pole of D1, the c pole of Q1 is electrically connected to Vcc2, the D pole of Q2 is electrically connected to the e pole of Q1, the S pole of Q2 is grounded, and one end of C1 is electrically connected to the e pole of Q1.

2. The circuit for improving the light resistance of an infrared touch frame according to claim 1, characterized in that: The G pole of Q2 inputs the DAC signal.

3. The circuit for improving the light resistance of an infrared touch frame according to claim 2, characterized in that: The Q2 is selected from MOSFET or triode.

4. The circuit for improving the light resistance of an infrared touch frame according to claim 3, characterized in that: A resistor may be connected in series between the D pole of Q2 and the e pole of Q1.

5. A method for improving the light resistance of an infrared touch frame, characterized in that: The steps include: Step 1: Vcc1 and Vcc2 are powered on to provide power to D1, R1 and Q1; Step 2: The G pole of Q2 is connected to the external control DAC signal; Step 3, by controlling and adjusting the conduction voltage drop of Q2, the gain of the first-stage current signal is adjusted; Step 4. Since the controller will continuously collect signal conditions, the software can judge the current ambient light status through the signal conditions, such as strong light, normal light, and weak light. According to different lighting conditions, it outputs the appropriate DAC value and controls the pre-stage amplification factor, thereby improving the adaptability of the entire system to ambient light.

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