CN210627166U - Infrared touch screen and signal gain adjusting circuit thereof - Google Patents
Infrared touch screen and signal gain adjusting circuit thereof Download PDFInfo
- Publication number
- CN210627166U CN210627166U CN201921806787.5U CN201921806787U CN210627166U CN 210627166 U CN210627166 U CN 210627166U CN 201921806787 U CN201921806787 U CN 201921806787U CN 210627166 U CN210627166 U CN 210627166U
- Authority
- CN
- China
- Prior art keywords
- resistor
- signal
- circuit
- array
- analog switch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
The utility model discloses an infrared touch-sensitive screen and signal gain control circuit thereof. The signal gain adjustment circuit includes: the resistor array comprises a plurality of resistors with different resistance values; a signal amplification circuit; the resistor array is connected with the signal amplification circuit, at least one resistor in the resistor array is connected into the signal amplification circuit, and the amplification factor of the signal amplification circuit is determined by the resistance value of the resistor connected into the resistor array; and the analog switch unit is provided with a selection control port and is used for controlling the resistor accessed to the signal amplification circuit in the resistor array according to a selection instruction output by the controller. The method adopts general materials to realize the automatic adjustment of the gain amplitude of the infrared pair tube, has good use performance, does not need to increase excessive cost, and is simple in realization method and reliable in performance.
Description
Technical Field
The utility model relates to a large-scale display device technical field, in particular to infrared touch-sensitive screen and signal gain control circuit thereof.
Background
The infrared touch screen is an interactive device which utilizes infrared geminate transistors arranged in a touch screen frame to realize detection of a user touch position. The specific principle is as follows: and detecting the shielding condition of the infrared signal to determine the current position of the user on the touch screen.
In the existing infrared touch screen, the signal gain multiple of the infrared touch signal is a parameter which is set by solidification before leaving a factory. The signal gain will remain constant throughout the life of the complete product.
However, the infrared gain signal solidified in this way cannot adapt to a variable infrared touch frame application environment, resulting in poor environmental adaptability of the product. For example, when the lamp is used outdoors and exposed to strong light, the problems of breaking points, writing and pulling lines and the like are likely to be caused.
And as time goes on, an automatic adjusting mechanism cannot be set, the problem that signals are weakened due to aging of infrared geminate transistors is solved, and the service life of the touch frame is greatly shortened.
In order to overcome the defects of the solidified infrared gain signals, some existing infrared touch screens adopt a programmable resistor mode to adjust the gain. However, when using a programming resistor, a special interface must be used to control the programming resistor, increasing the cost of the main controller of the infrared touch screen. Moreover, the use of programmable resistors also leads to increased costs.
Therefore, it is desirable to provide a suitable gain signal adjustment mechanism to solve various problems of the existing infrared touch screen.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing an infrared touch-sensitive screen and signal gain control circuit thereof can solve and has the contradiction between the signal gain control of infrared touch-sensitive screen and the cost of manufacture among the prior art.
In a first aspect, an embodiment of the present invention provides a signal gain adjustment circuit for infrared pair transistors. Wherein the signal gain adjustment circuit comprises:
the resistor array comprises a plurality of resistors with different resistance values;
a signal amplification circuit; the resistor array is connected with the signal amplification circuit, at least one resistor in the resistor array is connected into the signal amplification circuit, and the amplification factor of the signal amplification circuit is determined by the resistance value of the resistor connected into the resistor array;
and the analog switch unit is provided with a selection control port and is used for controlling the resistor accessed to the signal amplification circuit in the resistor array according to a selection instruction output by the controller.
Furthermore, the analog switch unit is an analog switch chip integrated with multiple channels; each path of analog switch is connected with one resistor in the resistor array, and the resistors connected into the signal amplification circuit are controlled by the on and off of the analog switches.
Further, the analog switch chip is 74HC 4052; the analog switch chip comprises two groups of bidirectional analog switches, and each group of bidirectional analog switches comprises 4 switches; and the selection control port of the analog switch chip is used for being connected with the GPIO port of the controller.
Further, the resistor array comprises four first to fourth array resistors with different resistance values;
the first array resistor, the second array resistor, the third array resistor, the fourth array resistor and the analog switch chip are respectively connected with four independent input/output pins of one group of bidirectional analog switches of the analog switch chip.
Further, the signal amplification circuit comprises an operational amplifier, a first resistor, a second resistor and a third resistor;
the positive phase input end of the operational amplifier is connected with the signal input end through a first resistor, the negative phase input end of the operational amplifier is connected with one end of the second resistor and one end of the third resistor, the other end of the second resistor is grounded, and the other end of the third resistor is connected with the output end of the operational amplifier;
the resistor array and the analog switch chip are connected in series between one end of the second resistor and the other end of the third resistor.
Further, a common input/output pin of the analog switch chip is connected with the other end of the third resistor.
Further, the signal amplification circuit further comprises a first capacitor, and the first capacitor is connected to a power supply circuit of the operational amplifier.
Further, the signal amplification circuit further comprises a fourth resistor; the fourth resistor is connected with the output end of the operational amplifier.
In a second aspect, an embodiment of the present invention provides an infrared touch screen. This infrared touch-sensitive screen includes: the touch screen comprises a screen body and an infrared pair tube circuit for detecting touch actions; the infrared pair tube circuit comprises the signal gain adjusting circuit, and is used for adjusting the gain of the infrared touch signal applied to the screen body by the user.
The embodiment of the utility model provides a signal gain control circuit adopts general material to realize the automatically regulated of infrared geminate transistors gain amplitude, does not need the cost that increases the controller when having good performance, and implementation method is simple and the dependable performance.
The signal gain adjusting circuit can enhance the use adaptability, prolong the service cycle of products, simultaneously not excessively increase the manufacturing cost, and has good application prospect.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without any creative effort.
Fig. 1 is a schematic diagram of a typical infrared pair tube circuit.
Fig. 2 is a schematic diagram of a signal gain adjustment circuit according to an embodiment of the present invention.
Fig. 3 is a schematic circuit diagram of a signal gain adjustment circuit according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
It is to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification 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.
It should be further understood that the term "and/or" as used in the specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.
Referring to fig. 1, fig. 1 shows a typical infrared pair transistor circuit. The infrared pair tube circuit mainly comprises three parts, namely an infrared pair tube 10, a signal conditioning circuit 20 for processing touch signals acquired by the infrared pair tube, and a power supply circuit 30 for supplying power.
The infrared pair tube 10 is generally composed of an infrared transmitting tube and an infrared receiving tube disposed opposite to each other. When a user performs touch operation on the infrared touch screen, the infrared rays of the infrared transmitting tube can be shielded, and the infrared receiving tube can acquire and obtain corresponding touch signals corresponding to shielding conditions.
The signal conditioning circuit 20 belongs to a circuit module for signal processing, and is configured to process an input signal and output the processed signal to a processor.
Under the influence of the actual application environment, the touch signals originally acquired by the infrared pair transistors 10 are weak and cannot be directly provided to a processor or the like for corresponding logic calculation. Therefore, a series of signal processing processes such as amplification and analog-to-digital conversion of the originally acquired touch signal by the signal conditioning circuit 20 are required.
Specifically, the signal conditioning circuit 20 may be any type or structure of signal processing circuit, and only needs to be able to meet the needs of practical use. It may be formed of a plurality of discrete electronic components or may be a chip integrated on a silicon wafer.
The power supply circuit 30 is a circuit module for providing stable power supply voltage and bias voltage to ensure normal operation of the infrared pair transistor circuit.
In signal conditioning circuit 20, can include like the utility model discloses the signal gain control circuit that provides to the realization is to the automatically regulated of infrared gain signal, satisfies the user demand under the different application environment.
Referring to fig. 2, the signal gain adjusting circuit may include: a resistor array 21, a signal amplification circuit 22, and an analog switch unit 23.
The resistor array is a circuit array composed of a plurality of resistors with different resistance values. Thus, the resistance value between the two ends of the resistor array can be changed according to the actual requirement.
In the present embodiment, the resistor array 21 is connected to the signal amplification circuit 22. At least one resistor in the resistor array 21 is connected to the signal amplification circuit.
Therefore, according to the resistance value of the resistor of the signal amplifying circuit accessed by the resistor array, the amplification factor of the amplifying circuit can be correspondingly changed, and the technical effect of adjustable signal gain is achieved.
The analog switch unit 23 is a functional unit integrating a plurality of analog switches and control components, and can adjust the resistance value that is finally presented in the signal amplification circuit across the resistor array by the closing and opening of the analog switches.
The analog switching unit 23 is a controlled electronic component. The signal amplification circuit is provided with a selection control port for controlling the resistor connected to the signal amplification circuit in the resistor array according to a selection instruction output by the controller, so that the amplification times of the signal amplification circuit can be adjusted.
In some embodiments, the analog switch unit 23 may be an analog switch chip integrated with multiple channels. Each path of analog switch is connected with one resistor in the resistor array, and the connection of the resistors specifically connected into the signal amplification circuit or the connection mode of the resistors is controlled by the disconnection and the connection of the analog switch.
In operation, the analog switch chip 22 may select a resistor in the resistor array to be coupled to the signal amplifier circuit according to a control signal from the controller. Therefore, different resistors in the resistor array are controlled to be connected into the signal amplifier circuit through the control signal, so that the resistor bridged between the inverting input end and the output end of the operational amplifier can be changed, and further, the signal amplification factor is changed to realize the adjustment of the signal gain.
Fig. 3 is a schematic circuit diagram of a signal gain adjustment circuit according to an embodiment of the present invention. As shown in fig. 3, the signal amplification circuit may include: an operational amplifier U1, a first resistor R1, a second resistor R2 and a third resistor R3.
The non-inverting input terminal + of the operational amplifier is connected to the signal input terminal MB through the first resistor R1, and the inverting input terminal-of the operational amplifier is connected to one end of the second resistor R2 and one end of the third resistor R3.
The other end of the second resistor R2 is grounded, and the other end of the third resistor R3 is connected to the output terminal out of the operational amplifier.
The resistor array 21 and the analog switch chip 22 are connected in series between one end of the second resistor and the other end of the third resistor, and are connected to the signal amplifier circuit 22.
In some embodiments, the signal amplification circuit may further include a fourth resistor R4. The fourth resistor R4 is connected to the output terminal of the operational amplifier, and the amplified signal is output from the output terminal of the signal amplifying circuit to the subsequent functional circuit via the fourth resistor R4.
Specifically, as shown in fig. 3, in the present embodiment, an analog switch chip of model 74HC4052 may be used. 74HC4052 is a two-out-of-four analog switch chip with common enable input control bits. Each group of multiplexing switches has four independent input/outputs (X0 to X3 and Y0 to Y3), a common input/output (X and Y) and select inputs (a and B). The selection input end of the analog switch chip is used as a selection control port and can receive a selection instruction to realize the control of the analog switch.
Preferably, the selection input end can be connected with a general GPIO port of the controller, no additional hardware equipment is needed, the cost can be effectively simplified, and the difficulty in implementation is reduced.
In some embodiments, as shown in fig. 3, the resistor array may include first through fourth array resistors (RG1, RG2, RG3, RG4) adapted to the analog switch chip.
One end of each of the first to fourth array resistors is connected to four independent input/output pins (e.g., X0 to X3) of one of the bidirectional analog switches of the analog switch chip, and the other end is connected to the signal amplification circuit. The corresponding common input/output terminal (e.g., X) of the analog switch chip is connected to the other terminal of the third resistor R3.
Of course, as shown in fig. 3, since 74HC4052 has two sets of independent multi-way analog switches, the other set of multi-way analog switches may also adopt similar connection forms, respectively connected to the fifth to eighth arrays of resistors, to realize the resistance adjustment of the other components.
In some embodiments, as shown in fig. 3, the operational amplifier U1 may be powered by a single power supply. That is, the first power supply terminal V + of the operational amplifier U1 is connected to the power supply terminal vcc, and the second power supply terminal V-is grounded.
The first power supply terminal V + of the operational amplifier U1 is also grounded through the first capacitor C1, which can perform a smoothing filtering function.
Similarly, the analog switch chip may also adopt the same power supply structure as the operational amplifier U1, and play a role of smoothing filtering through the second capacitor C2. Of course, the power supply terminals for supplying power to the operational amplifier U1 and the analog switch chip may be the same or different, and are determined according to the needs of the actual situation.
Further, the embodiment of the utility model provides a still provide an infrared touch screen. The signal gain adjusting circuit provided by the above embodiment can be applied to the infrared touch screen, and the signal gain of the infrared touch screen can be adjusted in a low-cost and general-purpose device manner.
The manufactured infrared touch screen has better adaptability, can meet the requirements of various different application environments, effectively prolongs the service cycle of the infrared touch screen, does not increase cost burden excessively, can be controlled by using the conventional universal control port, and has good application prospect.
To sum up, the embodiment of the utility model provides an infrared geminate transistor circuit adopts general material (zener diode and integrated fortune to put), through reasonable circuit design, and the effectual detected signal who solves infrared touch-sensitive screen is unstable, receives the problem of external disturbance influence easily.
The embodiments are described in a progressive manner in the specification, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.
It is further noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, 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 phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Claims (10)
1. A signal gain adjustment circuit, the signal gain adjustment circuit comprising:
the resistor array comprises a plurality of resistors with different resistance values;
a signal amplification circuit; the resistor array is connected with the signal amplification circuit, at least one resistor in the resistor array is connected into the signal amplification circuit, and the amplification factor of the signal amplification circuit is determined by the resistance value of the resistor connected into the resistor array;
and the analog switch unit is provided with a selection control port and is used for controlling the resistor accessed to the signal amplification circuit in the resistor array according to a selection instruction output by the controller.
2. The signal gain adjustment circuit of claim 1, wherein the analog switch unit is an analog switch chip integrated with multiple channels;
each path of analog switch is connected with one resistor in the resistor array, and the resistors connected into the signal amplification circuit are controlled by the on and off of the analog switches.
3. The signal gain adjustment circuit of claim 2, wherein the analog switch chip is 74HC 4052; the analog switch chip comprises two groups of bidirectional analog switches, and each group of bidirectional analog switches comprises 4 switches; and the selection control port of the analog switch chip is used for being connected with the GPIO port of the controller.
4. The signal gain adjustment circuit of claim 3, wherein the resistor array comprises four first to fourth array resistors having different resistance values;
the first array resistor, the second array resistor, the third array resistor, the fourth array resistor and the analog switch chip are respectively connected with four independent input/output pins of one group of bidirectional analog switches of the analog switch chip.
5. The signal gain adjustment circuit of claim 4, wherein four independent input/output pins of another set of bidirectional analog switches of the analog switch chip are respectively connected with the fifth to eighth array resistors.
6. The signal gain adjustment circuit of claim 4, wherein the signal amplification circuit comprises an operational amplifier, a first resistor, a second resistor, and a third resistor;
the positive phase input end of the operational amplifier is connected with the signal input end through a first resistor, the negative phase input end of the operational amplifier is connected with one end of the second resistor and one end of the third resistor, the other end of the second resistor is grounded, and the other end of the third resistor is connected with the output end of the operational amplifier;
the resistor array and the analog switch chip are connected in series between one end of the second resistor and the other end of the third resistor.
7. The signal gain adjustment circuit of claim 6, wherein a common input/output pin of the analog switch chip is connected to the other end of the third resistor.
8. The signal gain adjustment circuit of claim 6, wherein the signal amplification circuit further comprises a first capacitor connected to a supply circuit of the operational amplifier.
9. The signal gain adjustment circuit of claim 6, wherein the signal amplification circuit further comprises a fourth resistor; the fourth resistor is connected with the output end of the operational amplifier.
10. An infrared touch screen, comprising: the touch screen comprises a screen body and an infrared pair tube circuit for detecting touch actions; the infrared pair transistor circuit comprises the signal gain adjusting circuit as claimed in any one of claims 1 to 9, for adjusting the gain of the infrared touch signal generated by the touch action applied to the screen body by the user.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921806787.5U CN210627166U (en) | 2019-10-25 | 2019-10-25 | Infrared touch screen and signal gain adjusting circuit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921806787.5U CN210627166U (en) | 2019-10-25 | 2019-10-25 | Infrared touch screen and signal gain adjusting circuit thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210627166U true CN210627166U (en) | 2020-05-26 |
Family
ID=70751201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921806787.5U Active CN210627166U (en) | 2019-10-25 | 2019-10-25 | Infrared touch screen and signal gain adjusting circuit thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210627166U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113552969A (en) * | 2021-07-27 | 2021-10-26 | 高创(苏州)电子有限公司 | Infrared transmitter, receiver, touch device and touch display device |
| CN113934314A (en) * | 2020-07-13 | 2022-01-14 | 深圳市天英联合教育股份有限公司 | Signal gain adjusting circuit and system of infrared touch screen |
| WO2024041509A1 (en) * | 2022-08-26 | 2024-02-29 | 广州众远智慧科技有限公司 | Signal strength adjustment circuit, infrared touch-control apparatus and electronic device |
| WO2024060622A1 (en) * | 2022-09-21 | 2024-03-28 | 国创能源互联网创新中心(广东)有限公司 | Controller and control system for frequency converter, and electrical device |
-
2019
- 2019-10-25 CN CN201921806787.5U patent/CN210627166U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113934314A (en) * | 2020-07-13 | 2022-01-14 | 深圳市天英联合教育股份有限公司 | Signal gain adjusting circuit and system of infrared touch screen |
| CN113552969A (en) * | 2021-07-27 | 2021-10-26 | 高创(苏州)电子有限公司 | Infrared transmitter, receiver, touch device and touch display device |
| WO2024041509A1 (en) * | 2022-08-26 | 2024-02-29 | 广州众远智慧科技有限公司 | Signal strength adjustment circuit, infrared touch-control apparatus and electronic device |
| WO2024060622A1 (en) * | 2022-09-21 | 2024-03-28 | 国创能源互联网创新中心(广东)有限公司 | Controller and control system for frequency converter, and electrical device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN210627166U (en) | Infrared touch screen and signal gain adjusting circuit thereof | |
| AU2014212834B2 (en) | Programmable interface circuit for coupling field devices to process controllers | |
| EP0337396B1 (en) | Two-wire detection system having self-diagnosis means | |
| CN100489550C (en) | Voltage-applied current measuring instrument and current buffer with switch used therefor | |
| US5909660A (en) | Signal conditioning module for sensing multiform field voltage signals | |
| US4197471A (en) | Circuit for interfacing between an external signal and control apparatus | |
| CN108321762A (en) | A kind of short-circuit protection circuit | |
| WO2017113550A1 (en) | Operational amplifier, driver interface, measuring and control device, driver circuit and driver | |
| CN208112210U (en) | A kind of short-circuit protection circuit | |
| JPH05107292A (en) | Disconnection detector | |
| US8314679B2 (en) | Monitoring system and input device thereof | |
| US8319600B2 (en) | Monitoring system and input device thereof | |
| US8283937B2 (en) | Monitoring system and input and output device | |
| WO2023216578A1 (en) | Magnetic switch having filtering function | |
| CN218412767U (en) | Broken wire self-checking circuit based on Hall sensor | |
| CN207782765U (en) | Key detection circuit integrated with ambient brightness detection | |
| CN205691645U (en) | A kind of signal detection system | |
| CN109782660B (en) | Control circuit and device compatible with voltage-type and current-type analog input | |
| US20110175446A1 (en) | Monitoring system and input device thereof | |
| CN220671526U (en) | Input detection circuit compatible with resistance type current-mode voltage type | |
| CN207263857U (en) | capacitive load discharge control system | |
| CN206164917U (en) | Current detection and feedback circuit , switching power supply , LED drive circuit | |
| CN112636740B (en) | Signal input mode control circuit and method | |
| US8310091B2 (en) | Monitoring system and input and output device thereof | |
| CN221059605U (en) | Airflow detection chip, circuit, assembly and electronic atomization device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |