TWI514244B - Proximity sensing method and apparatus based on a capacitive touch display and communication terminal using thereof - Google Patents

Description

Short-distance sensing method and device based on capacitive touch screen and communication terminal

The present invention relates to the field of communications technologies, and in particular, to a proximity sensing method and apparatus based on a capacitive touch screen and a communication terminal.

At present, when a smart phone with a touch screen is used to make or receive a call, the touch screen often comes into contact with the human body. If the touch screen is not turned off, the system may malfunction. Therefore, a smart phone with a touch screen often has a proximity sensing function, so that when a person's face or other parts are detected to be close to the handset or the touch screen position during the call or answering call, the touch is turned off. Control the screen, or ignore the touch screen detection results to prevent human touch and cause misuse.

In the prior art, the above-mentioned proximity sensing function can be implemented in two ways. One way is to install a proximity sensor on the mobile phone. The sensor uses infrared to detect whether there is a human body or an object approaching. If the human body approaches a certain distance, the touch screen is locked. Another way is to use the touch screen to achieve close proximity sensing.

Please refer to Fig. 1. When a part of the human body, such as a human face, is close to the touch screen, the face and the plurality of electrodes (S-1~Sn) in the touch screen form a capacitor (C1~Cn). By detecting these capacitors (C1~Cn), the distance between the human body and the touch screen can be measured. However, since the human body and the touch screen are not in direct contact, these capacitors (C1~Cn) are relatively small, and are generally an order of magnitude smaller than those measured when directly touching, so the measurement results are not accurate enough. This makes the detection method less reliable.

In order to improve the detection accuracy, the commonly used method is to accumulate the data (D1~Dn) of the detection results of the plurality of electrodes on all or a specific area of the touch screen as above, and use the accumulated value to determine the distance, if the accumulated value When a certain threshold is reached, it is judged that the human body is close to the touch screen. Using the accumulated value will increase the detection data by a multiple, improve the detection accuracy, but at the same time, it will increase the noise.

Since the detected data is related, its amplitude is directly accumulated. It is assumed that the accumulated amplitude is D1+D2+...+Dn, and their noises are N1~Nn respectively. Since the noise is random and has no correlation, the noise is unknown. The cumulative amount is This value is larger than any of N1~Nn, so the noise amplitude will also increase.

It can be seen that the method of accumulating the detection results of the plurality of electrodes can improve the detection accuracy, but also increases the noise, so that the signal-to-noise ratio is not high enough, resulting in a small effective detection distance. In order to detect the proximity of the human body to the touch screen in time, it is necessary to further improve the effective detection distance of the touch screen detection.

In view of this, embodiments of the present invention provide a proximity sensing method and apparatus based on a capacitive touch screen and a communication terminal to improve an effective detection distance of the capacitive touch screen.

A first aspect of the present invention provides a proximity sensing method based on a capacitive touch screen, comprising: shorting N electrodes in a capacitive touch screen and connecting with a detecting circuit, wherein N is greater than or equal to 2; The detecting circuit detects the N electrodes; and calculates a distance between the capacitive touch screen and a nearby human body or object according to the detection result.

A second aspect of the present invention provides a proximity sensing device based on a capacitive touch screen, comprising: a connection module, configured to short-circuit N electrodes in the capacitive touch screen and connect with the detecting circuit, N The detection module is configured to detect the N electrodes by using a detection circuit, and the calculation module is configured to calculate a distance between the capacitive touch screen and a nearby human body or object according to the detection result of the detection module. .

The third embodiment of the present invention provides a communication terminal, including: a display screen, a capacitive touch screen attached to the display screen, a detecting circuit connected to the capacitive touch screen, and a processor, The processor is configured to control the N electrodes in the capacitive touch screen to be short-circuited with each other and connected to the detecting circuit when the communication terminal is in a call state, where N is greater than or equal to 2; Detecting the N electrodes; the processor is further configured to calculate a distance between the capacitive touch screen and a nearby human body or object according to the detection result of the detecting circuit.

In the embodiment of the present invention, the N electrodes in the capacitive touch screen are short-circuited to each other and connected to the detecting circuit, and then the distance detecting method is adopted, so that the detecting data of the N electrodes can be accumulated to improve the detection precision. At the same time, the detection noise is the same as the noise when detecting any one of the electrodes, and the noise is reduced compared with the prior art, and the signal-to-noise ratio is correspondingly improved, thereby effectively improving the effective detection distance of the capacitive touch screen.

S1-Sn‧‧‧ electrodes

C1-Cn‧‧‧ capacitor

101‧‧‧The N electrodes in the capacitive touch screen are shorted to each other and connected to the detection circuit, N is greater than or equal to 2

102‧‧‧Detecting the N electrodes by the detecting circuit

103‧‧‧ Calculate the distance between the capacitive touch screen and the nearby human body or object based on the test results

201‧‧‧Connecting module

202‧‧‧Test module

203‧‧‧Computation Module

401‧‧‧ display screen

402‧‧‧Capacitive touch screen

403‧‧‧Detection circuit

404‧‧‧ processor

1 is a schematic diagram of forming a plurality of capacitors by a plurality of electrodes in a proximity human body and a touch screen; FIG. 2 is a flowchart of a proximity sensing method based on a capacitive touch screen according to an embodiment of the present invention; FIG. 4 is a structural diagram of a proximity sensing device based on a capacitive touch screen according to an embodiment of the present invention; FIG. 4 is a schematic diagram of a proximity sensing device based on a capacitive touch screen according to an embodiment of the present invention; A schematic diagram of a communication terminal provided by an embodiment of the invention.

The embodiment of the invention provides a short-distance sensing method based on a capacitive touch screen, which can improve the signal-to-noise ratio of the detected data when detecting the distance of the human body by using the capacitive touch screen, thereby effectively improving the capacitive touch screen. Effective detection of distance. Embodiments of the present invention also provide corresponding Device and communication terminal. The details are described below separately.

Embodiment 1

Referring to FIG. 2, an embodiment of the present invention provides a proximity sensing method based on a capacitive touch screen. The method includes: 101. shorting N electrodes in a capacitive touch screen to each other, and detecting Circuit connection, N is greater than or equal to 2.

In the prior art, the N electrodes in the capacitive touch screen of the communication terminal are isolated from each other. During the detection process, each of the electrodes is separately detected by one or more detection circuits, and each detection is performed at each moment. The circuit detects only one electrode, and finally accumulates the data of each electrode detected.

In the embodiment of the present invention, when detecting, a certain area on the capacitive touch screen, for example, N electrodes in a region opposite to the close human body part, are short-circuited to each other, so that the N electrodes and the same detection are performed. Circuit connection. As shown in FIG. 3, each of the N electrodes S1-Sn can be connected to the input end of the detecting circuit by a wire to realize short-circuiting between the N electrodes and connection with the detecting circuit, and N is greater than or equal to 2.

Optionally, as shown in FIG. 3, a switch may be disposed in a connection line between each electrode and the detecting circuit, that is, the N electrodes are respectively connected to the input end of the detecting circuit through N switches; The detection can be performed by closing the N switches, connecting the control electrodes to the detection circuit, and shorting between the electrodes; when the N switches are off, other operations are performed. These switches can be controlled by software or hardware and can ultimately be controlled by the processor of the communication terminal.

102. The N electrodes are detected by the detecting circuit.

Since the N electrodes are connected to the detection circuit at the same time, when the detection circuit performs detection, the detection data of the N electrodes can be obtained at one time. Assuming that the capacitances of the N electrodes and the close human body parts are respectively C1-Cn, then the total capacitance C=C1+C2+...+Cn. The detection data in this step is D=D1+D2+...+Dn; D1-Dn is the detection data obtained when the N electrodes are respectively detected, and D is the cumulative sum. It can be seen that, in the present embodiment, the obtained detection data and the prior art respectively have the same effect of detecting and re-accumulating each electrode.

However, it is worth noting that the noise of the detected data in this embodiment will be smaller than in the prior art. It is assumed that the same detection circuit is used to detect N electrodes in the prior art, and the noise of the N detection data is M1-Mn, respectively, and the total noise is Because M1=M2=...Mn. In the technical solution of the embodiment of the present invention, the detection result is obtained only by detecting the detection circuit once, and the noise of the detection data is M1. It can be seen that the noise of the final detection data in the embodiment of the present invention is reduced compared with the noise of the final detection data in the prior art. Times.

If in the prior art, different N detection circuits are used to detect N electrodes, and the noises M1-Mn of the N detection data are not equal to each other, the noise of the detection data in the prior art is detected. No longer equal But still with Close. It is assumed that in the embodiment of the present invention, one of the N detecting circuits is used to detect N short-circuited electrodes at a time, and the noise of the detected data should be one of M1-Mn, still far Less noise than the detection data in the prior art , reduce the multiple and Close.

103. Calculate a distance between the capacitive touch screen and a nearby human body or object according to the detection result.

In this step, the distance between the capacitive touch screen and the nearby human body or object is calculated according to the detection data obtained by detecting the electrode. The calculation method is the same as the prior art, and will not be repeated herein. However, it should be noted that, as compared with the prior art, the amplitude of the detected data is unchanged, and the noise is reduced by about Times, that is, the signal to noise ratio is increased by about Times. Therefore, the embodiment of the invention has higher detection precision and detection distance, and the effective detection detection distance can even reach the detection method in the prior art. Times.

Optionally, after 103, the method further includes: turning off the capacitive touch screen when the detection distance is greater than or equal to a set threshold.

In summary, the embodiment of the present invention provides a proximity sensing method based on a capacitive touch screen, which uses N electrodes in a capacitive touch screen to be shorted to each other and connected to a detection circuit, and then performs distance detection. The technical solution can realize the accumulation of the detection data of the N electrodes to improve the detection precision, and at the same time, the detection noise is the same as the noise when the single electrode is separately detected, and the noise is reduced compared with the prior art, and the corresponding improvement is improved. The signal-to-noise ratio can effectively increase the effective detection distance of the capacitive touch screen, so that the human body or object can be detected closer to the capacitive touch screen at a greater distance.

Embodiment 2

Referring to FIG. 4, an embodiment of the present invention provides a capacitor based The proximity sensing device of the touch screen comprises: a connection module 201, which is used for shorting the N electrodes in the capacitive touch screen and connecting with the detecting circuit, N is greater than or equal to 2; the detecting module 202. The device is configured to detect the N electrodes by using the detecting circuit. The calculating module 203 is configured to calculate a distance between the capacitive touch screen and a nearby human body or object according to the detection result.

Optionally, the method further includes: closing the module, when the distance calculated by the computing module is greater than or equal to a set threshold, turning off the capacitive touch screen.

In one embodiment, the N electrodes are respectively connected to the input end of the detecting circuit through N switches; the connecting module is specifically configured to close the N switches to make the capacitive touch screen The N electrodes are shorted to each other and connected to the detection circuit.

For a more detailed description, please refer to the description in the first embodiment.

In summary, the embodiment of the present invention provides a proximity sensing device based on a capacitive touch screen, which uses N electrodes in a capacitive touch screen to be shorted to each other and connected to a detecting circuit, and then performs distance detection. The technical solution can realize the accumulation of the detection data of the N electrodes to improve the detection precision, and at the same time, the detection noise is the same as the noise when the single electrode is separately detected, and the noise is reduced compared with the prior art, and the corresponding improvement is improved. The signal-to-noise ratio can effectively increase the effective detection distance of the capacitive touch screen, so that the human body or object can be detected closer to the capacitive touch screen at a greater distance.

Embodiment 3

Referring to FIG. 5, a communication terminal includes a display screen 401, a capacitive touch screen 402 attached to the display screen, and a detection circuit connected to the capacitive touch screen 402. 403. The processor 404 is configured to: when detecting that the communication terminal is in a call state, control the N electrodes in the capacitive touch screen 402 to be shorted and connected to each other. The detecting circuit 403 is connected, N is greater than or equal to 2; the detecting circuit 403 is configured to detect the N electrodes; and the processor 404 is further configured to calculate a capacitive touch screen according to the detection result of the detecting circuit. The distance from a nearby human body or object.

Optionally, the processor 404 is further configured to turn off the capacitive touch screen when the distance is greater than or equal to a set threshold.

In one embodiment, the N electrodes are respectively connected to the input end of the detecting circuit through N switches; the processor 404 is specifically configured to detect the N switches when the communication terminal is in a call state. closure.

The communication terminal may be a common device such as a mobile phone, a tablet computer or a notebook computer, but is not limited thereto, and may be other devices with a capacitive touch screen, such as a paging communication device, a wearable communication device, etc. . All types of communication terminals using the technical solution of the present invention, which have a capacitive touch screen, should be covered by the protection of the present invention. Within the scope.

In summary, the embodiment of the present invention provides a communication terminal including a capacitive touch screen, which adopts a technical solution of short-circuiting N electrodes in a capacitive touch screen and connecting with a detection circuit, and then performing distance detection. The detection data of the N electrodes can be accumulated to improve the detection precision, and at the same time, the detection noise is the same as the noise when the single electrode is separately detected, and the noise is reduced compared with the prior art, and the signal noise is correspondingly improved. Therefore, the effective detection distance of the capacitive touch screen can be effectively improved, so that the human body or the object is detected closer to the capacitive touch screen at a greater distance.

A person skilled in the art can understand that all or part of the steps of the foregoing embodiments may be implemented by hardware, or may be implemented by a program instruction related hardware, and the program may be stored in a computer readable storage medium. The storage medium may include: read only memory, random read memory, magnetic disk or optical disc.

The short-distance sensing method and apparatus based on the capacitive touch screen and the communication terminal provided by the embodiments of the present invention are described in detail above, but the description of the above embodiments is only used to help understand the method and core idea of the present invention. It should not be construed as limiting the invention. Those skilled in the art will be able to devise variations or alternatives within the scope of the present invention within the scope of the present invention.

101‧‧‧The N electrodes in the capacitive touch screen are shorted to each other and connected to the detection circuit, N is greater than or equal to 2

102‧‧‧Detecting the N electrodes by the detecting circuit

103‧‧‧ Calculate the distance between the capacitive touch screen and the nearby human body or object based on the test results

Claims (10)

A proximity sensing method based on a capacitive touch screen includes: shorting N rows or N columns of electrodes in a capacitive touch screen and connecting with a detecting circuit, N is greater than or equal to 2; The detecting circuit detects the N rows or N columns of electrodes; and calculates the distance between the capacitive touch screen and a nearby human body or object according to the detection result. The proximity sensing method based on the capacitive touch screen of claim 1, wherein the capacitive touch screen is turned off when the distance is greater than or equal to a set threshold. The proximity sensing method of the capacitive touch screen according to claim 1, wherein the N rows or N columns of electrodes are respectively connected to the input end of the detecting circuit through N switches; the capacitive touch screen The N rows or N columns of electrodes are shorted to each other, and the connection with the detecting circuit includes: closing the N switches, so that the N rows or N columns of electrodes in the capacitive touch screen are shorted to each other, and The detection circuit is connected. A proximity sensing device based on a capacitive touch screen comprises: a connection module for shorting N rows or N columns of electrodes in a capacitive touch screen and connecting with the detecting circuit, N is greater than or equal to 2; a detection module for detecting the N rows or N columns of electrodes through the detection circuit; and a calculation module for calculating the capacitive touch screen and the nearby human body according to the detection result of the detection module Or the distance of the object. The proximity sensing device of the capacitive touch screen according to claim 4, further comprising a closing module, configured to turn off the capacitive touch when the distance calculated by the computing module is greater than or equal to a set threshold Screen. The proximity sensing device of the capacitive touch screen according to claim 4, wherein the N rows or N columns of electrodes are respectively connected to the input end of the detecting circuit through N switches; the connecting module is specifically used for The N switches are closed, so that the N rows or N columns of electrodes in the capacitive touch screen are shorted to each other and connected to the detecting circuit. A communication terminal includes: a display screen, a capacitive touch screen attached to the display screen, a detecting circuit connected to the capacitive touch screen, and a processor, wherein: the processing The device is configured to detect that the N rows or N columns of the capacitive touch screen are shorted to each other and connected to the detecting circuit when the communication terminal is in a call state, and N is greater than or equal to 2; the detecting circuit is configured to The N-row or N-column electrodes are detected; and the processor is further configured to calculate a distance between the capacitive touch screen and a nearby human body or object according to the detection result of the detection circuit. The communication terminal of claim 7, wherein the processor is further configured to turn off the capacitive touch screen when the distance is greater than or equal to a set threshold. The communication terminal according to claim 7, wherein: the N rows or N columns of electrodes respectively pass the N switches and the detection power The input end of the road is connected; and the processor is specifically configured to control the N switches to be closed when the communication terminal is in a call state. The communication terminal of any one of claims 7 to 9, wherein the communication terminal can be a mobile phone, a tablet or a notebook.