CN218568017U

CN218568017U - Sampling circuit of infrared touch frame, infrared touch screen and terminal equipment

Info

Publication number: CN218568017U
Application number: CN202222199821.5U
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Guangzhou Zhongyuan Intelligent Technology Co ltd
Current assignee: Guangzhou Zhongyuan Intelligent Technology Co ltd
Priority date: 2022-08-19
Filing date: 2022-08-19
Publication date: 2023-03-03
Anticipated expiration: 2032-08-19

Abstract

The embodiment of the application provides a sampling circuit of an infrared touch frame, an infrared touch screen and a terminal device, wherein the sampling circuit of the infrared touch frame comprises a plurality of infrared signal receiving channels, a plurality of filter circuits, a plurality of amplifying circuits, a plurality of signal holding circuits and a microprocessor; each infrared signal receiving channel is connected with the input end of one filter circuit, and the output end of each filter circuit is connected with the input end of one amplifying circuit; the signal holding circuit comprises an input end, an output end and a driving end; the output end of each amplifying circuit is connected with the input end of one signal holding circuit, the output end of each signal holding circuit is connected with one signal input end of the microprocessor, and the driving end of each signal holding circuit is connected with the control output end of the microprocessor, so that the infrared signal sampling efficiency is improved.

Description

Sampling circuit of infrared touch frame, infrared touch screen and terminal equipment

Technical Field

The embodiment of the application relates to the technical field of signal processing, in particular to a sampling circuit of an infrared touch frame, an infrared touch screen and a terminal device.

Background

The working principle of the infrared touch frame is that a plurality of paths of infrared signals are received, analog-to-digital conversion and touch algorithm processing are carried out on the plurality of paths of infrared signals through a microprocessor, and the coordinate position of a touch point is obtained. The infrared signals need to be sampled before the microprocessor acquires the plurality of infrared signals.

In the prior art, for received multiple paths of infrared signals, one path of infrared signals in the multiple paths of infrared signals is sequentially selected through an analog switch to be amplified, and then the amplified signals are input to a microprocessor. However, only one path of infrared signal is sampled at a time, so that the sampling speed is low and the efficiency is low.

SUMMERY OF THE UTILITY MODEL

In order to overcome the problems in the related art, the application provides a sampling circuit of an infrared touch frame, an infrared touch screen and a terminal device, which can improve the efficiency of infrared signal sampling.

According to a first aspect of the embodiments of the present application, a sampling circuit of an infrared touch frame is provided, which includes a plurality of infrared signal receiving channels, a plurality of filter circuits, a plurality of amplifying circuits, a plurality of signal holding circuits, and a microprocessor;

each infrared signal receiving channel is connected with the input end of one filter circuit, and the output end of each filter circuit is connected with the input end of one amplifying circuit; the signal holding circuit comprises an input end, an output end and a driving end; the output end of each amplifying circuit is connected with the input end of one signal holding circuit, the output end of each signal holding circuit is connected with one signal input end of the microprocessor, and the driving end of each signal holding circuit is connected with the control output end of the microprocessor.

According to a second aspect of the embodiment of the application, an infrared touch screen is provided, which comprises a display screen and an infrared touch frame, wherein the infrared touch frame is arranged around the display screen;

the sampling circuit of infrared touch frame includes: the device comprises a plurality of infrared signal receiving channels, a plurality of filter circuits, a plurality of amplifying circuits, a plurality of signal holding circuits and a microprocessor;

According to a third aspect of embodiments of the present application, there is provided a terminal device, including: an infrared touch screen; the infrared touch screen comprises a display screen and an infrared touch frame;

The embodiment of the application realizes sampling of a plurality of paths of infrared signals after amplification processing through mutual matching of the plurality of filter circuits, the plurality of amplification circuits and the plurality of signal holding circuits, and improves the sampling speed and efficiency of the infrared signals. Meanwhile, after the infrared signals are processed by the signal holding circuit, the signals are stable, and the sampling precision of the infrared signals is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

For a better understanding and an implementation, the present invention is described in detail below with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application 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 of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic circuit diagram of a sampling circuit of an infrared touch frame according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a circuit configuration of a signal holding circuit according to an embodiment of the present application;

fig. 3 is a schematic circuit diagram of a signal holding circuit according to another embodiment of the present application;

FIG. 4 is a schematic circuit diagram of a signal holding circuit according to yet another embodiment of the present application;

fig. 5 is a schematic structural diagram of an infrared touch screen according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

It should be understood that the embodiments described are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated.

In the description of the present application, it is to be understood that the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not necessarily used to describe a particular order or sequence, nor are they to be construed as indicating or implying relative importance. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The word "if as used herein may be interpreted as" at 8230; \8230when "or" when 8230; \8230when "or" in response to a determination ". Further, in the description of the present application, "a plurality" means two or more unless otherwise specified. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

Please refer to fig. 1, which is a schematic circuit structure diagram of a sampling circuit of an infrared touch frame according to an embodiment of the present application. The sampling circuit of the infrared touch frame of the embodiment of the application is applied to various infrared touch screens and is mainly used for improving the sampling efficiency of infrared signals.

Specifically, the sampling circuit of the infrared touch frame in the embodiment of the present application includes a plurality of infrared signal receiving channels 100, a plurality of filter circuits 200, a plurality of amplifying circuits 300, a plurality of signal holding circuits 400, and a microprocessor 500;

each infrared signal receiving channel 100 is connected with the input end of one filter circuit 200, and the output end of each filter circuit 200 is connected with the input end of one amplifying circuit 300; signal holding circuit 400 includes an input terminal, an output terminal, and a drive terminal; the output terminal of each amplifying circuit 300 is connected to the input terminal of one signal holding circuit 400, the output terminal of each signal holding circuit 400 is connected to one signal input terminal of the microprocessor 500, and the driving terminal of each signal holding circuit 400 is connected to the control output terminal of the microprocessor 500.

The infrared touch frame is provided with a plurality of infrared transmitting tubes and a plurality of infrared receiving tubes, the infrared transmitting tubes and the infrared receiving tubes are in one-to-one correspondence to form infrared matrixes which are crossed horizontally and vertically, the infrared transmitting tubes transmit infrared signals, and the infrared receiving tubes receive the corresponding infrared signals. Each infrared signal receiving channel 100 is connected to an infrared receiving tube for receiving the infrared signal output by the infrared receiving tube. The microprocessor 500 may be any processor that performs infrared signal acquisition, and in the present embodiment, the microprocessor 500 is of the type MC68VZ328.

The infrared signal is received through the infrared signal receiving channel 100, and the infrared signal is input to the filter circuit 200 for filtering. The infrared signal is subjected to noise filtering by the filter circuit 200, so that the filtered infrared signal is stable and has strong anti-interference capability. The filtered infrared signal is input to an amplifying circuit 300 for amplification; because the received infrared signal is weak and there is a certain distortion and loss in the transmission process, the infrared signal is amplified by the amplifying circuit 300 with adjustable gain in a certain range, so that the infrared signal is enhanced. Since the infrared signal is changed in the sampling process, the sampling time is required to be as short as possible, the collected infrared signal can be stored through the signal holding circuit 400 and is kept for a certain time, and therefore the sampling precision of the infrared signal is guaranteed. The microprocessor 500 is used for performing analog-to-digital conversion on the infrared signal to obtain the coordinate position of the touch point.

The sampling after the multichannel infrared signals are amplified simultaneously is realized through the mutual cooperation of the plurality of filter circuits 200, the amplifying circuit 300 and the plurality of signal holding circuits 400, and the sampling speed and the efficiency of the infrared signals are improved. Meanwhile, after the infrared signal is processed by the signal holding circuit 400, the signal is stable, and the sampling precision of the infrared signal is improved.

In one embodiment, the filter circuit 200 includes an inductor having low-pass and high-pass characteristics, which can suppress high-frequency noise in the infrared signal, thereby having a filtering effect. In an alternative embodiment, the filter circuit 200 may include a single or multiple inductors connected in series.

In another embodiment, the filter circuit 200 includes a magnetic bead, which is equivalent to a resistor and an inductor connected in series, and can suppress high-frequency noise in the infrared signal, thereby having a filtering effect. In an alternative embodiment, the filter circuit 200 may comprise a single or a series of multiple beads.

In another embodiment, the filter circuit 200 includes a capacitor having the characteristics of passing high frequency and blocking low frequency, and can suppress low frequency noise in the infrared signal, thereby performing a filtering function.

In one embodiment, the amplifying circuit 300 includes a plurality of cascaded operational amplifiers, so as to amplify the infrared signal in multiple stages, thereby enhancing the infrared signal.

In one embodiment, the operational amplifier is an active filter amplifier or a programmable gain amplifier, and the amplifying circuit 300 may be formed by cascading a plurality of active filter amplifiers, a plurality of programmable gain amplifiers, or an active filter amplifier and a programmable gain amplifier in a spaced cascade. The active filter amplifier is an operational amplifier used for dynamically inhibiting harmonic waves and compensating reactive power, and can compensate harmonic waves with variable sizes and frequencies and variable reactive power. The program control gain amplifier is an operational amplifier which generates different feedback coefficients according to different control signals so as to change the closed-loop gain.

In one embodiment, referring to fig. 2, the signal holding circuit 400 includes a first analog switch S1 and a first holding capacitor C1; the input end of the first analog switch S1 is connected with the output end of the amplifying circuit 300, and the output end of the first analog switch S1 is connected with the signal input end of the microprocessor 500; the driving end of the first analog switch S1 is connected to the control output end of the microprocessor 500; two ends of the first holding capacitor C1 are respectively connected with the output end of the first analog switch S1 and the ground end.

Specifically, when the circuit is in a sampling state, the driving end of the first analog switch S1 is at a high level, so that the first analog switch S1 is turned on, and the first holding capacitor C1 is charged; when the circuit is in the hold state, the driving terminal of the first analog switch S1 is at a low level, so that the first analog switch S1 is turned off, and since the signal input terminal of the microprocessor 500 is at a high impedance, the first holding capacitor C1 discharges slowly, so that the infrared signal is kept at a signal level value at the turn-off instant.

In another embodiment, referring to fig. 3, the signal holding circuit 400 includes a first operational amplifier A1, a second operational amplifier A2, a second analog switch S2, a first resistor R1, a second resistor R2, a third resistor R3, and a second holding capacitor C2;

the non-inverting input end of the first operational amplifier A1 is connected with the output end of the amplifying circuit 300, the inverting input end of the first operational amplifier A1 is connected with the signal input end of the microprocessor 500, and the output end of the first operational amplifier A1 is connected with the input end of the second analog switch S2; the output end of the second analog switch S2 is connected with the first end of the first resistor R1, and the driving end of the second analog switch S2 is connected with the control output end of the microprocessor 500; the second end of the first resistor R1 is connected with the first end of the second resistor R2 and the first end of the second holding capacitor C2; a second end of the second holding capacitor C2 is connected to ground, a second end of the second resistor R2 is connected to a non-inverting input terminal of the second operational amplifier A2, and an inverting input terminal of the second operational amplifier A2 is connected to a signal input terminal of the microprocessor 500 through a third resistor R3.

Specifically, when the circuit is in a sampling state, the driving end of the second analog switch S2 is at a high level, so that the second analog switch S2 is turned on, and the second holding capacitor C2 is charged; when the circuit is in a holding state, the driving end of the second analog switch S2 is at a low level, so that the second analog switch S2 is turned off, and since the input ends of the first resistor R1, the second resistor R2 and the second operational amplifier A2 are all high impedance, the second holding capacitor C2 discharges slowly, so that the infrared signal is kept at a signal level value at the moment of turning off.

In another embodiment, referring to fig. 4, the signal holding circuit 400 includes a third operational amplifier A3, a fourth operational amplifier A4, a third analog switch S3 and a third holding capacitor C3;

the non-inverting input terminal of the third operational amplifier A3 is connected to the output terminal of the amplifying circuit 300, and the inverting input terminal of the third operational amplifier A3 is connected to the output terminal of the third operational amplifier A3 and the input terminal of the third analog switch S3; the output end of the third analog switch S3 is connected with the non-inverting input end of the fourth operational amplifier A4, and the driving end of the third analog switch S3 is connected with the control output end of the microprocessor 500; the inverting input terminal of the fourth operational amplifier A4 is connected to the output terminal of the fourth operational amplifier A4 and the signal input terminal of the microprocessor 500, and two terminals of the third holding capacitor C3 are respectively connected to the non-inverting input terminal and the ground terminal of the fourth operational amplifier A4.

Specifically, when the circuit is in a sampling state, the driving end of the third analog switch S3 is at a high level, so that the third analog switch S3 is turned on, and the third holding capacitor C3 is charged; when the circuit is in a hold state, the driving terminal of the third analog switch S3 is at a low level, so that the third analog switch S3 is turned off, and since the input terminal of the fourth operational amplifier A4 is at a high impedance, the third holding capacitor C3 discharges slowly, so that the infrared signal is maintained at a signal level value at the moment of turning off.

In one embodiment, microprocessor 500 includes an analog-to-digital converter that includes several input channels, one input channel being connected to each signal holding circuit 400.

Specifically, each input channel of the analog-to-digital converter can convert one infrared signal into a corresponding digital signal, thereby improving the resource utilization rate of the microprocessor 500.

Referring to fig. 5, an embodiment of the present application further provides an infrared touch screen 10, which includes a display screen 101 and an infrared touch frame 102, where the infrared touch frame 102 is disposed around the display screen 101, a sampling circuit 103 of the infrared touch frame is disposed in the infrared touch frame 102, and a structure of the sampling circuit 103 of the infrared touch screen is completely the same as that described above, and is not described herein again.

Referring to fig. 6, an embodiment of the present application further provides a terminal device 700, which includes an infrared touch screen 701; the structure of the infrared touch screen 701 is completely the same as that described above, and is not described in detail here.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. The utility model provides a sampling circuit of infrared touch frame which characterized in that: the infrared signal receiving device comprises a plurality of infrared signal receiving channels, a plurality of filter circuits, a plurality of amplifying circuits, a plurality of signal holding circuits and a microprocessor;

2. The sampling circuit of the infrared touch frame of claim 1, wherein:

the signal holding circuit comprises a first analog switch and a first holding capacitor;

the input end of the first analog switch is connected with the output end of the amplifying circuit, and the output end of the first analog switch is connected with the signal input end of the microprocessor; the driving end of the first analog switch is connected with the control output end of the microprocessor; and two ends of the first holding capacitor are respectively connected with the output end of the first analog switch and the ground end.

3. The sampling circuit of the infrared touch frame of claim 1, wherein:

the signal holding circuit comprises a first operational amplifier, a second analog switch, a first resistor, a second resistor, a third resistor and a second holding capacitor;

the non-inverting input end of the first operational amplifier is connected with the output end of the amplifying circuit, the inverting input end of the first operational amplifier is connected with the signal input end of the microprocessor, and the output end of the first operational amplifier is connected with the input end of the second analog switch; the output end of the second analog switch is connected with the first end of the first resistor, and the driving end of the second analog switch is connected with the control output end of the microprocessor; the second end of the first resistor is connected with the first end of the second resistor and the first end of the second holding capacitor; a second end of the second holding capacitor is connected to ground, a second end of the second resistor is connected to a non-inverting input terminal of the second operational amplifier, and an inverting input terminal of the second operational amplifier is connected to a signal input terminal of the microprocessor via the third resistor.

4. The sampling circuit of the infrared touch frame of claim 1, wherein:

the signal holding circuit comprises a third operational amplifier, a fourth operational amplifier, a third analog switch and a third holding capacitor;

the non-inverting input end of the third operational amplifier is connected with the output end of the amplifying circuit, and the inverting input end of the third operational amplifier is connected with the output end of the third operational amplifier and the input end of the third analog switch; the output end of the third analog switch is connected with the non-inverting input end of the fourth operational amplifier, and the driving end of the third analog switch is connected with the control output end of the microprocessor; and the inverting input end of the fourth operational amplifier is connected with the output end of the fourth operational amplifier and the signal input end of the microprocessor, and two ends of the third holding capacitor are respectively connected with the non-inverting input end of the fourth operational amplifier and the ground end.

5. The infrared touch frame sampling circuit of any one of claims 1 to 4, wherein each of the filter circuits comprises a capacitor, an inductor, or a magnetic bead.

6. The sampling circuit of the infrared touch frame of any one of claims 1 to 4, wherein: the microprocessor comprises an analog-to-digital converter, the analog-to-digital converter comprises a plurality of input channels, and the output end of each signal holding circuit is connected with one input channel.

7. The sampling circuit of the infrared touch frame of any one of claims 1 to 4, wherein: the amplifying circuit comprises a plurality of cascaded operational amplifiers.

8. The sampling circuit of the infrared touch frame of claim 7, wherein: the operational amplifier is an active filter amplifier or a program control gain amplifier.

9. An infrared touch screen, comprising: the infrared touch frame is arranged around the display screen in a surrounding manner;

the sampling circuit of the infrared touch frame comprises: the device comprises a plurality of infrared signal receiving channels, a plurality of filter circuits, a plurality of amplifying circuits, a plurality of signal holding circuits and a microprocessor;

10. A terminal device, comprising: an infrared touch screen; the infrared touch screen comprises a display screen and an infrared touch frame;