CN213934849U - Infrared signal processing circuit and infrared touch screen - Google Patents
Infrared signal processing circuit and infrared touch screen Download PDFInfo
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- CN213934849U CN213934849U CN202023009971.2U CN202023009971U CN213934849U CN 213934849 U CN213934849 U CN 213934849U CN 202023009971 U CN202023009971 U CN 202023009971U CN 213934849 U CN213934849 U CN 213934849U
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Abstract
The utility model relates to an infrared signal processing circuit and infrared touch-sensitive screen, include: the infrared light receiving circuit, the first high-pass filter circuit, the first voltage amplifier, the second high-pass filter circuit and the second voltage amplifier. A high-pass filter with high cut-off frequency is formed by adding a resistance to the ground after a blocking capacitor of the existing infrared signal processing circuit, so that the time of the signal reaching the peak value is accelerated.
Description
Technical Field
The utility model relates to an infrared technology field especially relates to an infrared signal processing circuit and infrared touch screen.
Background
Referring to fig. 1, a prior art infrared signal processing circuit includes: the device comprises a photosensitive diode, a first blocking capacitor, a first analog switch, a first voltage amplifier, a second blocking capacitor, a second analog switch and a second voltage amplifier, wherein the first voltage amplifier is used for converting the output current of the first blocking capacitor into voltage and realizing voltage amplification, and the second voltage amplifier is used for converting the output current of the second blocking capacitor into voltage and realizing voltage amplification. In the infrared signal processing circuit in the prior art, the blocking capacitor can be theoretically equivalent to a high-pass circuit with the cutoff frequency of 0, and at this time, due to the existence of a low-frequency signal, the time for the signal to reach the peak value is longer, so that the scanning time of the whole circuit is longer.
Disclosure of Invention
The embodiment of the utility model provides an infrared signal processing circuit and infrared touch screen can effectively solve the technical problem that signal reached peak time overlength among the prior art infrared signal processing circuit, has effectively shortened the holistic scanning time of circuit.
To achieve the above object, one embodiment of the present invention provides an infrared signal circuit, including: the infrared light receiving circuit, first high pass filter circuit, first voltage amplifier, second high pass filter circuit and second voltage amplifier, infrared light circuit with first high pass filter circuit is connected, first high pass filter circuit is connected with first voltage amplifier, first voltage amplifier with the second high pass filter circuit is connected, the second high pass filter circuit with the second voltage amplifier is connected, its characterized in that, wherein:
the first high-pass filter circuit includes: first electric capacity, first resistance and reference voltage source port, the one end of first electric capacity with infrared light receiving circuit's output is connected, the other end of first electric capacity with first resistance is connected, first resistance with the terminal that first electric capacity is connected does first high pass filter circuit's output, the other end of first resistance with the reference voltage source port is connected.
Preferably, the second high-pass filter circuit includes: a second capacitor and a second resistor;
one end of the second capacitor is connected with the output end of the first voltage amplifier, the other end of the second capacitor is connected with one end of the second resistor, the connecting end is the output end of the second high-pass filter circuit, and the other end of the second resistor is grounded.
Specifically, the infrared light receiving circuit includes: first voltage source port, infrared receiving diode and third resistance, wherein: the first voltage source port is connected with the cathode of the infrared receiving diode; the anode of the infrared receiving diode is connected with one end of the third resistor; the other end of the third resistor is grounded.
Further, the circuit further comprises a first analog switch and a second analog switch, wherein one end of the first analog switch is connected with the output end of the first high-pass filter circuit, and the other end of the first analog switch is connected with the reference voltage source port; one end of the second analog switch is connected with the output end of the second high-pass filter circuit, and the other end of the second analog switch is grounded.
Specifically, the first voltage amplifier includes: first operational amplifier, fourth resistance, fifth resistance, sixth resistance and third electric capacity, wherein: one end of the fourth resistor is connected with the output end of the first high-pass filter circuit, and the other end of the fourth resistor is connected with the positive phase input end of the first operational amplifier; the fifth resistor is connected with the third capacitor in parallel, one end of the fifth resistor is connected with the inverting input end of the first operational amplifier, and the other end of the fifth resistor is connected with the output end of the first operational amplifier; one end of the sixth resistor is connected with the inverting input end of the first operational amplifier, and the other end of the sixth resistor is connected with the reference voltage source port;
the second voltage amplifier includes: second operational amplifier, seventh resistance, eighth resistance, ninth resistance and fourth electric capacity, wherein: one end of the seventh resistor is connected with the output end of the second high-pass filter circuit, and the other end of the seventh resistor is connected with the positive-phase input end of the second operational amplifier; the eighth resistor is connected in parallel with the fourth capacitor, and one end of the eighth resistor is connected with the inverting input end of the second operational amplifier, and the other end of the eighth resistor is connected with the output end of the second operational amplifier; and one end of the ninth resistor is connected with the inverting input end of the second operational amplifier, and the other end of the ninth resistor is grounded.
Another embodiment of the utility model provides another infrared signal processing circuit, include: the infrared light receiving circuit is connected with the first high-pass filter circuit, the first high-pass filter circuit is connected with the first voltage amplifier, the output end of the first voltage amplifier is connected with the non-inverting input end of the second voltage amplifier, and the second high-pass filter circuit is connected with the inverting input end of the second voltage amplifier, wherein:
the first high-pass filter circuit includes: first electric capacity, first resistance and reference voltage source port, the one end of first electric capacity with infrared light receiving circuit's output is connected, the other end of first electric capacity with first resistance is connected, the second resistance with the terminal that first electric capacity is connected does first high pass filter circuit's output, the other end of second resistance with the reference voltage source port is connected.
Further, the second high-pass filter circuit includes: a second resistor, a third capacitor and a fourth capacitor; the third capacitor is connected with the fourth capacitor in parallel, one end of the third capacitor is connected with one end of the second resistor, and the other end of the third capacitor is grounded; the other end of the second resistor is connected with the inverting input end of the second voltage amplifier.
The infrared light receiving circuit, the first voltage amplifier and the second voltage amplifier in this embodiment have the same structure as the previous embodiment, and are not described again.
The utility model also provides an infrared touch screen, it adopts foretell infrared signal processing circuit.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a circuit diagram of a prior art IR signal processing circuit;
fig. 2 is a circuit diagram of an infrared signal processing circuit according to a first embodiment of the present invention;
fig. 3 is a circuit diagram of an infrared signal processing circuit according to a second embodiment of the present invention;
fig. 4 is a circuit diagram of an infrared signal processing circuit according to a third embodiment of the present invention;
fig. 5 is a timing diagram of the filtering signal output of the present invention.
Detailed Description
In order to make the technical solutions in the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall belong to the protection scope of the present invention.
Fig. 1 is a circuit diagram of the prior art mid-infrared signal processing circuit of the present invention. As shown in fig. 1, the related art infrared signal processing circuit includes: the infrared light receiving circuit comprises an infrared light receiving circuit, a first blocking capacitor, a first analog switch, a first voltage amplifier, a second blocking capacitor, a second analog switch and a second voltage amplifier, wherein the first voltage amplifier is used for converting output current of the first blocking capacitor into voltage and realizing voltage amplification, and the second voltage amplifier is used for converting output current of the second blocking capacitor into voltage and realizing voltage amplification. In the infrared signal processing circuit in the prior art, the blocking capacitor can be theoretically equivalent to a high-pass circuit with a cutoff frequency of 0, at this time, due to the existence of a low-frequency signal, the time for the signal to reach a peak value is longer, and further, the scanning time of the whole circuit is prolonged, the time sequence diagram of the circuit is shown in fig. 5, and as can be seen from fig. 5, the rising of the output signal is slower after passing through the blocking capacitor.
First embodiment
In order to shorten the time that the signal reaches the peak value, the utility model discloses a circuit structure of infrared signal processing circuit is proposed in the first embodiment, as shown in fig. 2, it all connects a resistance to ground at the output of current first, second stopping electric capacity, and this resistance and first, second stopping electric capacity constitute high pass filter, specifically:
the infrared signal processing circuit of the present embodiment includes: the infrared light receiving circuit is connected with the first high-pass filter circuit, the first high-pass filter circuit is connected with the first voltage amplifier, the first voltage amplifier is connected with the second high-pass filter circuit, and the second high-pass filter circuit is connected with the second voltage amplifier.
As shown in fig. 2, the first high-pass filter circuit includes: the infrared light receiving circuit comprises a first capacitor C1, a first resistor R6 and a reference voltage source port Vref, wherein one end of the first capacitor C1 is connected with the output end of the infrared light receiving circuit, the other end of the first capacitor C1 is connected with one end of the first resistor R6, a terminal of the first resistor R6 connected with the first capacitor C1 is the output end of the first high-pass filter circuit, and the other end of the first resistor R6 is connected with the reference voltage source port Vref.
Further, the second high-pass filter circuit includes: one end of a second capacitor C2, one end of a second resistor R5 and one end of a second capacitor C2 are connected with the output end of the first voltage amplifier, the other end of the second capacitor C2 is connected with a second resistor R5, the terminal of the second resistor R5 connected with the second capacitor C2 is the output end of the second high-pass filter circuit, and the other end of the second resistor R5 is grounded.
Further, the infrared light receiving circuit includes: a first voltage source port VCC, an infrared receiving diode REV1, and a third resistor RX1, wherein: the first voltage source port VCC is connected with the cathode of the infrared receiving diode REV 1; the anode of the infrared receiving diode REV1 is connected to one end of the third resistor RX1, and the other end of the third resistor RX1 is grounded.
Further, as shown in fig. 2, the infrared signal processing circuit further includes a first analog switch and a second analog switch, where the analog switch is a switch circuit controlled by a corresponding control circuit CTRL, one end of the first analog switch is connected to the output end of the first high-pass filter circuit, and the other end of the first analog switch is connected to the reference voltage source port Vref; one end of the second analog switch is connected with the output end of the second high-pass filter circuit, and the other end of the second analog switch is grounded.
Specifically, the first voltage amplifier includes: a first operational amplifier U1A, a fourth resistor R1, a fifth resistor R3, a sixth resistor R8 and a third capacitor C4, wherein: one end of the fourth resistor R1 is connected with the output end of the first high-pass filter circuit, and the other end is connected with the non-inverting input end of the first operational amplifier U1A; the fifth resistor R3 is connected in parallel with the third capacitor C4, and has one end connected to the inverting input terminal of the first operational amplifier U1A and the other end connected to the output terminal of the first operational amplifier U1A; one end of the sixth resistor R8 is connected to the inverting input terminal of the first operational amplifier U1A, and the other end is connected to the reference voltage source port Vref.
The second voltage amplifier includes: a second operational amplifier U1B, a seventh resistor R2, an eighth resistor R4, a ninth resistor R9 and a fourth capacitor C5, wherein: one end of the seventh resistor R2 is connected with the output end of the second high-pass filter circuit, and the other end of the seventh resistor R2 is connected with the non-inverting input end of the second operational amplifier U1B; the eighth resistor R4 is connected in parallel with the fourth capacitor C5, and one end of the eighth resistor R4 is connected to the inverting input terminal of the second operational amplifier U1B, and the other end of the eighth resistor R4 is connected to the output terminal of the second operational amplifier U1B; one end of the ninth resistor R9 is connected to the inverting input terminal of the second operational amplifier U1B, and the other end of the ninth resistor R9 is grounded.
With the circuit, after the first blocking capacitor of the prior art is added to the ground resistor to form a high-pass filter, the rising edge of the signal becomes steep and the time for the signal to reach the peak value is shortened as can be seen from the timing diagram of fig. 5.
Second embodiment
Fig. 3 is a circuit diagram of an infrared signal processing circuit according to a second embodiment of the present invention.
Compared with the prior art, the improvement point is that the first analog switch and the second analog switch are removed, and the resistors are added to the ground after the first blocking capacitor and the second blocking capacitor to form two high-pass filters, so that the time of the signal reaching the peak value is further shortened, and the other circuit components are the same as those of the first embodiment and are not repeated.
Third embodiment
Fig. 4 is a circuit diagram of an infrared signal processing circuit according to a third embodiment of the present invention.
A third embodiment is a further improvement of the second high-pass filter circuit on the basis of the second embodiment. The output end of the first voltage amplifier U1A is connected to the non-inverting input end of the second voltage amplifier U1B, and the second high-pass filter circuit is connected to the inverting input end of the second voltage amplifier U1B, wherein: the second high-pass filter circuit includes: a second resistor R8, a third capacitor C8 and a fourth capacitor C9; the third capacitor C8 is connected in parallel with the fourth capacitor C9, one end of the third capacitor C8 is connected with one end of the second resistor R8, and the other end of the third capacitor C8 is grounded; the other end of the second resistor R8 is connected to the inverting input of the second voltage amplifier U1B. The rest of the circuit components are the same as those in the second embodiment, and are not described again.
Fig. 5 shows a comparison of signal waveforms of the prior art and the first embodiment of the present invention. As can be seen from figure 5, the utility model discloses a mode that increases to ground resistance at blocking capacitor output constitutes high pass filter, constitutes the higher high pass filter of cutoff frequency, has changed the rising edge of signal for the speed of signal arrival peak value.
Further, the utility model also discloses an infrared touch screen, it includes above-mentioned infrared signal processing circuit.
It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
Claims (10)
1. An infrared signal processing circuit comprising: the infrared light receiving circuit is connected with the first high-pass filter circuit, the first high-pass filter circuit is connected with the first voltage amplifier, the first voltage amplifier is connected with the second high-pass filter circuit, and the second high-pass filter circuit is connected with the second voltage amplifier, wherein:
the first high-pass filter circuit includes: first electric capacity, first resistance and reference voltage source port, the one end of first electric capacity with infrared light receiving circuit's output is connected, the other end of first electric capacity with first resistance is connected, first resistance with the terminal that first electric capacity is connected does first high pass filter circuit's output, the other end of first resistance with the reference voltage source port is connected.
2. The infrared signal processing circuit of claim 1, wherein the second high pass filter circuit comprises: a second capacitor and a second resistor;
one end of the second capacitor is connected with the output end of the first voltage amplifier, the other end of the second capacitor is connected with one end of the second resistor, the connecting end is the output end of the second high-pass filter circuit, and the other end of the second resistor is grounded.
3. The infrared signal processing circuit according to claim 1 or 2, wherein the infrared light receiving circuit comprises: a first voltage source port, a photodiode, and a third resistor, wherein:
the first voltage source port is connected with the cathode of the photosensitive diode;
the anode of the photosensitive diode is connected with one end of the third resistor;
the other end of the third resistor is grounded.
4. The infrared signal processing circuit of claim 3, further comprising a first analog switch and a second analog switch, wherein one end of the first analog switch is connected to the output of the first high pass filter circuit and the other end of the first analog switch is connected to the reference voltage source port; one end of the second analog switch is connected with the output end of the second high-pass filter circuit, and the other end of the second analog switch is grounded.
5. The infrared signal processing circuit of claim 4,
the first voltage amplifier includes: first operational amplifier, fourth resistance, fifth resistance, sixth resistance and third electric capacity, wherein:
one end of the fourth resistor is connected with the output end of the first high-pass filter circuit, and the other end of the fourth resistor is connected with the positive phase input end of the first operational amplifier;
the fifth resistor is connected with the third capacitor in parallel, one end of the fifth resistor is connected with the inverting input end of the first operational amplifier, and the other end of the fifth resistor is connected with the output end of the first operational amplifier;
one end of the sixth resistor is connected with the inverting input end of the first operational amplifier, and the other end of the sixth resistor is connected with the reference voltage source port;
the second voltage amplifier includes: second operational amplifier, seventh resistance, eighth resistance, ninth resistance and fourth electric capacity, wherein:
one end of the seventh resistor is connected with the output end of the second high-pass filter circuit, and the other end of the seventh resistor is connected with the positive-phase input end of the second operational amplifier;
the eighth resistor is connected in parallel with the fourth capacitor, and one end of the eighth resistor is connected with the inverting input end of the second operational amplifier, and the other end of the eighth resistor is connected with the output end of the second operational amplifier;
and one end of the ninth resistor is connected with the inverting input end of the second operational amplifier, and the other end of the ninth resistor is grounded.
6. An infrared signal processing circuit comprising: the infrared light receiving circuit is connected with the first high-pass filter circuit, the first high-pass filter circuit is connected with the first voltage amplifier, the output end of the first voltage amplifier is connected with the non-inverting input end of the second voltage amplifier, and the second high-pass filter circuit is connected with the inverting input end of the second voltage amplifier, wherein:
the first high-pass filter circuit includes: first electric capacity, first resistance and reference voltage source port, the one end of first electric capacity with infrared light receiving circuit's output is connected, the other end of first electric capacity with first resistance is connected, first resistance with the terminal that first electric capacity is connected does first high pass filter circuit's output, the other end of first resistance with the reference voltage source port is connected.
7. The infrared signal processing circuit of claim 6, wherein the second high pass filter circuit comprises: a second resistor, a third capacitor and a fourth capacitor;
the third capacitor is connected with the fourth capacitor in parallel, one end of the third capacitor is connected with one end of the second resistor, and the other end of the third capacitor is grounded; the other end of the second resistor is connected with the inverting input end of the second voltage amplifier.
8. The infrared signal processing circuit as claimed in claim 6 or 7, wherein the infrared light receiving circuit comprises: first voltage source port, infrared receiving diode and third resistance, wherein:
the first voltage source port is connected with the cathode of the infrared receiving diode;
the anode of the infrared receiving diode is connected with one end of the third resistor;
the other end of the third resistor is grounded.
9. The infrared signal processing circuit of claim 8,
the first voltage amplifier includes: first operational amplifier, fourth resistance, fifth resistance, sixth resistance and third electric capacity, wherein:
one end of the fourth resistor is connected with the output end of the first high-pass filter circuit, and the other end of the fourth resistor is connected with the positive phase input end of the first operational amplifier;
the fifth resistor is connected with the third capacitor in parallel, one end of the fifth resistor is connected with the inverting input end of the first operational amplifier, and the other end of the fifth resistor is connected with the output end of the first operational amplifier;
one end of the sixth resistor is connected with the inverting input end of the first operational amplifier, and the other end of the sixth resistor is connected with the reference voltage source port;
the second voltage amplifier includes: second operational amplifier, seventh resistance, eighth resistance, ninth resistance and fourth electric capacity, wherein:
one end of the seventh resistor is connected with the output end of the second high-pass filter circuit, and the other end of the seventh resistor is connected with the positive-phase input end of the second operational amplifier;
the eighth resistor is connected in parallel with the fourth capacitor, and one end of the eighth resistor is connected with the inverting input end of the second operational amplifier, and the other end of the eighth resistor is connected with the output end of the second operational amplifier;
and one end of the ninth resistor is connected with the inverting input end of the second operational amplifier, and the other end of the ninth resistor is grounded.
10. An infrared touch screen characterized by comprising the infrared signal processing circuit according to any one of claims 1 to 9.
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CN202023009971.2U CN213934849U (en) | 2020-12-14 | 2020-12-14 | Infrared signal processing circuit and infrared touch screen |
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CN202023009971.2U CN213934849U (en) | 2020-12-14 | 2020-12-14 | Infrared signal processing circuit and infrared touch screen |
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