Capacitance detection method and capacitance detection device

Abstract

The application provides a capacitance detection method for a capacitance detection device, which comprises the following steps: obtaining a first capacitance measurement value of a detection channel in a first working mode in a first environment state and a second capacitance measurement value of the detection channel in a second working mode in the first environment state; obtaining a third capacitance measurement value of the detection channel in the first working mode in a second environment state and a fourth capacitance measurement value of the detection channel in the second working mode in the second environment state; and determining a capacitance measurement change value of a bypass channel and a capacitance measurement change value of the detection channel according to the obtained capacitance measurement values, and determining a compensated capacitance measurement value of the detection channel. By using the technical scheme, the change of the parasitic capacitance caused by the change of the environment can be corrected, so that the touch capacitance detection precision is ensured, and misjudgment is avoided. The application further provides a capacitance detection device.

Description

Technical Field

[0001] This application relates to the field of touch detection, and more particularly to a capacitance detection method and a capacitance detection device. Background Technology

[0002] A capacitive sensor is a device that converts the measured physical or mechanical quantity into a change in capacitance. Due to its advantages such as simple structure, stable performance, and high sensitivity, capacitive sensors are widely used in industrial and consumer electronics products, such as for measuring pressure, displacement, acceleration, thickness, and liquid level.

[0003] The basic working principle of a capacitive sensor: A capacitance detection circuit converts the change in the sensor's capacitance into an electrical signal output. By measuring the magnitude of this electrical signal, the magnitude of the measured quantity can be determined. Summary of the Invention

[0004] Some embodiments of this application provide a capacitance detection method and a capacitance detection device. The following describes this application from multiple aspects, and the embodiments and beneficial effects of the following aspects can be referred to each other.

[0005] In a first aspect, embodiments of this application provide a capacitance detection method for a capacitance detection device. The method includes: acquiring a first capacitance measurement value of a detection channel in a first operating mode under a first environmental state, and a second capacitance measurement value in a second operating mode under the same first environmental state. The first operating mode is that the detection channel and a bypass channel are disconnected; the second operating mode is that the detection channel and the bypass channel are connected. The detection channel includes a detection channel trace, one end of which is connected to the capacitance detection device, and the other end of which is connected to the capacitor to be detected. The bypass channel includes a bypass channel trace, one end of which is connected to the capacitance detection device. The other end of the channel trace is floated; the third capacitance measurement value of the detection channel in the first working mode under the second environmental state and the fourth capacitance measurement value in the second working mode under the second environmental state are acquired, wherein the environmental parameters of the second environmental state are different from those of the first environmental state; the capacitance measurement change value of the bypass channel is determined based on the difference between the second capacitance measurement value and the first capacitance measurement value, and the difference between the fourth capacitance measurement value and the third capacitance measurement value; the capacitance measurement change value of the detection channel is determined based on the first capacitance measurement value and the third capacitance measurement value; the capacitance measurement change value of the compensated detection channel is determined based on the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel.

[0006] The capacitance detection method provided by the first aspect of this application can correct capacitance changes caused by environmental changes, thereby ensuring capacitance detection accuracy and avoiding misjudgment.

[0007] In some embodiments, determining the capacitance measurement change value of the bypass channel based on the difference between the second capacitance measurement value and the first capacitance measurement value, and the difference between the fourth capacitance measurement value and the third capacitance measurement value, includes: determining a first capacitance measurement difference value as the difference between the second capacitance measurement value and the first capacitance measurement value, and determining a second capacitance measurement difference value as the difference between the fourth capacitance measurement value and the third capacitance measurement value; and determining the capacitance measurement change value of the bypass channel based on the first capacitance measurement difference value and the second capacitance measurement difference value. This improves calculation speed while ensuring the accuracy of the first capacitance measurement difference value and the second capacitance measurement difference value.

[0008] In some implementations, determining the capacitance change value of the bypass channel based on the first capacitance measurement difference and the second capacitance measurement difference includes: determining the capacitance change value of the bypass channel based on the difference between the second capacitance measurement difference and the first capacitance measurement difference. This improves calculation speed while ensuring the accuracy of the capacitance change value of the bypass channel.

[0009] In some implementations, determining the capacitance change value of the detection channel based on the first capacitance measurement value and the third capacitance measurement value includes: determining the capacitance change value of the detection channel based on the difference between the third capacitance measurement value and the first capacitance measurement value. This improves the calculation speed while ensuring the accuracy of the capacitance change value of the detection channel.

[0010] In some implementations, the compensated capacitance measurement value of the detection channel is determined based on the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel. This includes: determining a compensation coefficient based on the ratio of the capacitance measurement change value of the detection channel to the capacitance measurement change value of the bypass channel; and determining the compensated capacitance measurement value of the detection channel based on the product of the compensation coefficient and the capacitance measurement change value of the bypass channel. This can correct for capacitance changes caused by environmental variations, improve capacitance detection accuracy, and avoid misjudgments.

[0011] In some implementations, the compensated capacitance measurement value of the detection channel is determined based on the product of the compensation coefficient and the capacitance measurement change value of the bypass channel. This includes determining the compensated capacitance measurement value of the detection channel based on the difference between the third capacitance measurement value and the product. This allows for more accurate compensation for capacitance changes caused by environmental variations, improving capacitance detection accuracy and avoiding misjudgments.

[0012] Secondly, embodiments of this application provide a capacitance detection device, comprising: a detection capacitance sensor for acquiring a first capacitance measurement value of a detection channel in a first operating mode under a first environmental state and a third capacitance measurement value in the same first operating mode under a second environmental state; a bypass capacitance sensor for acquiring a second capacitance measurement value of the detection channel in a second operating mode under the same first environmental state and a fourth capacitance measurement value therein; and a digital processing unit for determining a capacitance measurement change value of the bypass channel based on the difference between the second and first capacitance measurement values ​​and the difference between the fourth and third capacitance measurement values, determining a capacitance measurement change value of the detection channel based on the first and third capacitance measurement values, and determining a compensated capacitance measurement value of the detection channel based on the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel. This device can correct for capacitance changes caused by environmental variations, thereby ensuring capacitance detection accuracy and avoiding misjudgments. Attached Figure Description

[0013] Figure 1 This illustrates application scenarios of the capacitance detection device provided according to some embodiments of this application.

[0014] Figure 2(a) shows a schematic diagram of a capacitance detection device provided according to some embodiments of the present application in a first operating mode.

[0015] Figure 2(b) shows a schematic diagram of the capacitance detection device provided according to some embodiments of the present application in a second operating mode.

[0016] Figure 3 A flowchart of a capacitance detection method provided according to some embodiments of this application is shown.

[0017] Figure 4 A flowchart illustrating the determination of capacitance measurement changes in a bypass channel according to some embodiments of this application is shown.

[0018] Figure 5 A flowchart illustrating the determination of the capacitance measurement value of the compensated detection channel according to some embodiments of this application is shown.

[0019] Figure 6 This diagram shows a block diagram of a capacitance detection device according to some embodiments of the present application;

[0020] Figure 7 This diagram illustrates a block diagram of a SoC (System on Chip) according to some embodiments of this application. Detailed Implementation

[0021] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0022] Figure 1 The following illustrations show application scenarios of the capacitance detection device provided according to some embodiments of this application. The capacitance detection device is described as an example of a touch sensor.

[0023] like Figure 1 As shown, the touch sensor employs a self-capacitance structure, including a touch electrode. In other embodiments, the touch sensor may also employ a mutual capacitance structure; this is not specifically limited here, and those skilled in the art can choose the specific type of touch sensor as needed.

[0024] A parasitic capacitance C0 is formed between the touch plate and the reference ground. When a finger approaches the touch plate, a variable capacitance ΔC is formed between the finger and the touch plate. Since the human body has a relatively large capacitance, its potential is equivalent to ground. Therefore, during the process of the finger approaching the touch plate, the capacitance C from the touch plate to ground... x It includes two parts: parasitic capacitance C0 and variable capacitance ΔC, that is, C x =C0 + ΔC. By detecting the magnitude of ΔC, it can be determined whether a finger has touched the object and the location of the touch.

[0025] Touch sensors can be specifically applied to wearable devices (e.g.) Figure 1 Watches (300 or bracelets), mobile phones (200, such as...) Figure 1 Electronic devices with touchscreens, such as tablets, laptops, ultra-mobile personal computers (UMPCs), handheld computers, netbooks, personal digital assistants (PDAs), and virtual reality devices, are not specifically limited to these categories in this application.

[0026] Figure 2(a) shows a schematic diagram of a capacitance detection device provided according to some embodiments of this application in a first operating mode. As shown in Figure 2(a), the capacitance detection device 100 is presented in the form of a chip. In other embodiments, the capacitance detection device 100 may also be in other forms, such as circuits, which are not specifically limited here, as long as they can achieve the function of capacitance detection. The capacitance detection device 100 can be used to detect the capacitance value of a capacitor 400 to be detected. In this embodiment, the capacitor 400 to be detected is the capacitance in a touch sensor (e.g., a SAR touch sensor).

[0027] As shown in Figure 2(a), the touch sensor employs a self-capacitance structure, including a touch electrode. A parasitic capacitance C0 is formed between the touch electrode and the reference ground. When a finger approaches the touch electrode, a variable capacitance ΔC is formed between the finger and the touch electrode. Since the human body has a relatively large capacitance, its potential is equivalent to ground. Therefore, during the process of the finger approaching the touch electrode, the capacitance C from the touch electrode to ground... x It includes two parts: parasitic capacitance C0 and variable capacitance ΔC, that is,

[0028] C x =C0+ΔC (1)

[0029] However, when the capacitance detection device 100 is used to detect the capacitance C of the touch plate... x During testing, wiring is inevitably required, as shown in Figure 2(a). The testing channel includes testing channel wiring 1, one end of which is connected to the capacitance detection device 100, and the other end is connected to the capacitor 400 to be tested. Therefore, the actual capacitance C of the testing channel... senor Including the capacitor C of the touch plate x And the capacitor C of the detection channel trace 1 trace1 Two parts, namely,

[0030] C sensor =C x +C trace1 (2)

[0031] From the above formulas (1) and (2), it can be seen that the capacitance C of the detection channel is... senor It is affected by the proximity of objects (such as a human body or a conductor) (i.e., the variable capacitance ΔC). However, it is also susceptible to environmental changes such as temperature and humidity (i.e., the parasitic capacitance C0 between the touch plate and the reference ground and the capacitance C of the detection channel trace 1 caused by environmental changes). trace1 (Changes in capacitance C0 and capacitance C of detection channel trace 1 caused by environmental changes). trace1 When the change in capacitance is equivalent to the change in variable capacitance ΔC caused by an object (human body or conductor) approaching the touch plate, it will cause misjudgment (for example, a finger does not touch the screen, but is misjudged as having touched it, and then the screen lights up).

[0032] Therefore, to minimize the impact of environmental changes (temperature, humidity, etc.) on the capacitance detection value of the detection channel and ensure capacitance detection accuracy, especially to avoid misjudgments caused by environmental changes, this application proposes a capacitance detection device 100 and a capacitance detection method applied to the capacitance detection device 100, which can suppress capacitance changes caused by environmental changes. In other words, according to the capacitance detection device 100 and capacitance detection method of this application, capacitance changes caused by environmental changes can be corrected.

[0033] As shown in Figure 2(a), the capacitance detection device 100 includes: a detection channel pin CS, a bypass channel pin CP of the detection channel, a controllable connection channel (e.g., a connecting line connecting the detection channel pin CS and the bypass channel pin CP) for connecting the detection channel and the bypass channel, a capacitance digital conversion unit (e.g., a Capacitor Digital Conversion, CDC), and a data processing unit. The detection channel pin CS is used to connect to the detection channel trace 1, and the bypass channel pin CP is used to connect to the bypass channel trace 2. In some possible embodiments, at least a portion of the bypass channel trace 2 is parallel to the detection channel trace 1, thereby ensuring that the surrounding conditions of the bypass channel and the detection channel are as consistent as possible, improving compensation accuracy, and thus ensuring the detection accuracy of the capacitance detection device 100. In this embodiment, the detection channel trace 1 and the bypass channel trace 2 are identical and parallel to each other to eliminate the influence of other variables on the bypass channel detection result.

[0034] The capacitance-to-digital converter (CPC) is connected to both the detection channel pin CS and the data processing unit, and the bypass channel pin CP can also be connected via a connection channel. It converts the capacitance 400 to be detected into a digital value, which is then transmitted to the data processing unit. The data processing unit processes the data output from the CPC to obtain a compensated capacitance measurement value.

[0035] By controlling the opening and closing of the connection channel, the bypass channel and the detection channel are kept in a disconnected and connected state, respectively. In some embodiments, a switch SW is provided on the connection channel. The switch SW is controlled to open and close by a signal from a control unit (not shown in the figure, but may be a control unit located in the capacitor-to-digital converter unit), thereby opening and closing the connection channel, and thus keeping the bypass channel and the detection channel in a disconnected and connected state, respectively. The switch SW can be implemented using a circuit including a transistor.

[0036] As shown in Figure 2(a), when the switch SW is open, the bypass channel and the detection channel are disconnected. That is, in the first working mode, the detection channel is connected to the capacitor-to-digital converter unit, and the bypass channel is not connected to the capacitor-to-digital converter unit.

[0037] Figure 2(b) shows a schematic diagram of the capacitance detection device provided according to some embodiments of the present application in a second operating mode. As shown in Figure 2(b), when the switch SW is closed, the detection channel and the bypass channel are connected, that is, in the second operating mode, both the detection channel and the bypass channel are connected to the capacitance digital conversion unit, and the detection channel pin CS and the bypass channel pin CP are short-circuited.

[0038] As described above, the switch SW is located outside the capacitor-to-digital converter unit. It is understood that in some embodiments, the switch SW or its equivalent may also be located inside the capacitor-to-digital converter unit, and the connection channel between the detection channel and the bypass channel is also located inside the capacitor-to-digital converter unit.

[0039] By controlling the disconnection and connection of the connection channel, the detection mode can be switched between the first working mode and the second working mode. This allows the capacitance measurement values ​​of the detection channel corresponding to different working modes under different environmental conditions to be obtained. This determines the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel, and then determines the compensation coefficient to compensate for the capacitance value measured after environmental changes, thereby improving the detection accuracy of the capacitance detection device 100.

[0040] For example, in a first environmental state, a first capacitance measurement value of the detection channel in a first operating mode and a second capacitance measurement value in a second operating mode are acquired; in a second environmental state, a third capacitance measurement value of the detection channel in the first operating mode and a fourth capacitance measurement value in the second operating mode are acquired, wherein the environmental parameters of the first and second environmental states are different, for example, at least one of temperature, humidity, and air pressure changes. Then, based on the first, second, third, and fourth capacitance measurement values, the capacitance measurement change value of the bypass channel is determined; based on the first and third capacitance measurement values, the capacitance measurement change value of the detection channel is determined. Then, based on the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel, the compensated capacitance measurement value of the detection channel is determined. Thus, the change in capacitance measurement value of the detection channel caused by environmental changes can be compensated, thereby improving the accuracy of the capacitance detection device 100 and avoiding misjudgment.

[0041] Figure 3 A flowchart of a capacitance detection method according to some embodiments of this application is shown. The following is in conjunction with… Figure 3 The capacitance detection method using the capacitance detection device of this application is described in detail.

[0042] This application provides a capacitance detection method, including the following steps:

[0043] Step S1: Obtain the first capacitance measurement value of the detection channel in the first operating mode under the first environmental state and the second capacitance measurement value after switching the first operating mode to the second operating mode. As mentioned above, refer to... Figure 1 As shown in Figure 2, in the first operating mode, the detection channel and the bypass channel are disconnected; in the second operating mode, the detection channel and the bypass channel are connected. The detection channel includes detection channel trace 1, one end of which is connected to a capacitance detection device (e.g., Figure 1And the other end of the detection channel trace 1 (and the detection channel pin CS in Figure 2) is connected to the capacitor to be detected 400 (e.g. Figure 1 The bypass channel is connected to the touch plate in the middle. The bypass channel is placed side by side with the detection channel. The bypass channel includes bypass channel trace 2. One end of bypass channel trace 2 is connected to the capacitance detection device (e.g., Figure 1 It is connected to the bypass channel pin (CP) in Figure 2, and the other end of the bypass channel trace is floating.

[0044] For example, in the first environmental state, reference Figure 1 When switch SW is open, the detection channel performs detection and acquires the first capacitance measurement value in the first operating mode. At this time, the detection channel is connected to the capacitance digital conversion unit of the capacitance detection device 100, while the bypass channel is not connected to the capacitance digital conversion unit of the capacitance detection device 100. Therefore, the first capacitance measurement value is equal to the sum of the capacitance of the capacitor to be detected 400 and the capacitance of the detection channel trace 1.

[0045] C sensor-E1-M1 =C x-E1 +C trace1-E1 (3)

[0046] In formula (3), C sensor-E1-M1 To detect the first capacitance measurement value of the detection channel under the first operating mode M1 in the first environmental state E1; C x-E1 The capacitance of the capacitor to be tested 400 in the first environmental state E1; C trace1-E1 To detect the capacitance of channel trace 1 in the first environmental state E1.

[0047] Referring to Figure 2, when switch SW is closed, the system switches from the first operating mode to the second operating mode. The detection channel performs detection and acquires the second capacitance measurement value in the second operating mode. At this time, both the detection channel and the bypass channel are connected to the capacitance digital conversion unit of the capacitance detection device 100. The detection channel pin CS and the bypass channel pin CP are short-circuited. Therefore, the second capacitance measurement value is equal to the sum of the capacitance of the capacitor to be detected 400, the capacitance of the detection channel trace 1, and the capacitance of the bypass channel trace 2.

[0048] C sensor-E1-M2 =C x-E1 +C trace1-E1 +C trace2-E1 (4)

[0049] In formula (4), C sensor-E1-M2 To measure the second capacitance value of the detection channel under the second operating mode M2 ​​in the first environmental state E1; C x-E1 The capacitance of the capacitor to be tested 400 in the first environmental state E1; C trace1-E1 To detect the capacitance of channel trace 1 in the first environmental state E1; Ctrace2-E1 The capacitor of bypass channel line 2 in the first environmental state E1.

[0050] Step S2: Obtain the third capacitance measurement value of the detection channel in the first working mode under the second environmental state and the fourth capacitance measurement value after switching the first working mode to the second working mode. The environmental parameters of the second environmental state differ from those of the first environmental state. "Environmental parameters" can be understood as physical quantities that reflect the environmental state, such as temperature, humidity, and air pressure, thereby correcting for capacitance changes caused by at least one of temperature, humidity, and air pressure, and improving capacitance detection accuracy.

[0051] For example, in a second environmental state (e.g., the temperature in the second environmental state is 25°C, the temperature in the first environmental state is 15°C, and other environmental parameters remain unchanged), refer to Figure 1 When switch SW is open, the detection channel performs detection and acquires the third capacitance measurement value in the first operating mode. At this time, the detection channel is connected to the capacitance digital conversion unit of the capacitance detection device 100, while the bypass channel is not connected to the capacitance digital conversion unit of the capacitance detection device 100. Therefore, the third capacitance measurement value is equal to the sum of the capacitance to be detected and the capacitance of the detection channel trace 1.

[0052] C sensor-E2-M1 =C x-E2 +C trace1-E2 (5)

[0053] In formula (5), C sensor-E2-M1 To measure the third capacitance value of the detection channel in the first operating mode M1 under the second environmental state E2; C x-E2 The capacitance of the capacitor to be tested 400 in the second environmental state E2; C trace1-E2 To detect the capacitance of channel trace 1 in the second environmental state E2.

[0054] Referring to Figure 2, when switch SW is closed, the system switches from the first operating mode to the second operating mode. The detection channel performs detection and acquires the fourth capacitance measurement value in the second operating mode. At this time, both the detection channel and the bypass channel are connected to the capacitance digital conversion unit of the capacitance detection device 100. The detection channel pin CS and the bypass channel pin CP are short-circuited, therefore the fourth capacitance measurement value C is obtained. sensor-E2-M2 It equals the sum of the capacitance of the capacitor under test, the capacitance of detection channel trace 1, and the capacitance of bypass channel trace 2, i.e.

[0055] C sensor-E2-M2＝ C x-E2 +C trace1-E2 +C trace2-E2 (6)

[0056] In formula (6), Csensor-E1-M2 To measure the fourth capacitance value of the detection channel in the second operating mode M2 ​​under the second environmental state E2; C x-E2 The capacitance of the capacitor to be tested 400 in the second environmental state E2; C trace1-E2 To detect the capacitance of channel trace 1 in the second environmental state E2; C trace2-E2 The capacitor for bypass channel trace 2 in the second environmental state E2.

[0057] Step S3: Determine the capacitance change value of the bypass channel based on the difference between the second capacitance measurement value and the first capacitance measurement value and the difference between the fourth capacitance measurement value and the third capacitance measurement value.

[0058] Figure 4 A flowchart illustrating the determination of capacitance measurement changes in a bypass channel according to some embodiments of this application is shown below. Figure 4 This section details the steps for determining the capacitance change value of the bypass channel.

[0059] It should be noted that the capacitance change value of the bypass channel can be understood as the capacitance change value of bypass channel trace 2. The following example uses the first environmental state as the initial environmental state.

[0060] Step S31 involves determining a first capacitance measurement difference, which is the difference between the second capacitance measurement value and the first capacitance measurement value, and a second capacitance measurement difference, which is the difference between the fourth capacitance measurement value and the third capacitance measurement value. This improves calculation speed while ensuring the accuracy of both the first and second capacitance measurement differences.

[0061] From formulas (4)-(3), we know that the difference in the first capacitance measurement = the second capacitance measurement value - the first capacitance measurement value = C sensor-E1-M2 -C sensor-E1-M1 =(C x-E1 +C trace1-E1 +C trace2-E1 )-(C x-E1 +C trace1-E1 ) = C trace2-E1 (7)

[0062] From formulas (6)-(5), we know that the difference in the second capacitance measurement = the fourth capacitance measurement value - the third capacitance measurement value = C sensor-E2-M2 -C sensor-E2-M1 =(C x-E2 +C trace1-E2 +C trace2-E2 )-(C x-E2 +C trace1-E2 ) = C trace2-E2 (8)

[0063] Step S32: Based on the difference between the first and second capacitance measurements, determine the capacitance measurement change value of the bypass channel. This improves the calculation speed while ensuring the accuracy of the capacitance measurement change value of the bypass channel.

[0064] In some possible embodiments, the change in capacitance measurement of the bypass channel can be determined based on the difference between the second capacitance measurement difference and the first capacitance measurement difference.

[0065] From formulas (7) and (8), it can be seen that the capacitance change value of the bypass channel, that is, the capacitance change value ΔC of the bypass channel trace, is... trace2-E1-E2 =Difference in second capacitance measurement - Difference in first capacitance measurement = C trace2-E2 -C trace2-E1 =(C sensor-E2-M2 -C sensor-E2-M1 )-C sensor-E1-M2 -C sensor-E1-M1 (9),

[0066] In formula (9), ΔC trace2-E1-E2 The capacitance change of the bypass channel trace 2 as it changes from the first environmental state E1 to the second environmental state E2 is the measured capacitance change of the bypass channel trace.

[0067] Step S4: Based on the third capacitance measurement value and the first capacitance measurement value, determine the capacitance measurement change value of the detection channel. This improves the calculation speed while ensuring the accuracy of the capacitance measurement change value of the detection channel.

[0068] In some possible embodiments, the change in capacitance measurement of the detection channel can be determined based on the difference between the third capacitance measurement and the first capacitance measurement.

[0069] From formulas (3) and (5), it can be seen that the capacitance change value ΔC of the detection channel is... sensor-E1-E2 =Third capacitor measurement value - First capacitor measurement value = C sensor-E2 -C sensor-E1 =(C x-E2 +C trace1-E2 )-(C x-E1 +C trace1-E1 )=(C x-E2 -C x-E1 )+(C trace1-E2 -C trace1-E1 )=ΔC x-E1-E2 +ΔC trace1-E1-E2 (10)

[0070] In formula (10), ΔC x-E1-E2 The capacitor 400 to be detected changes from the first environmental state E1 to the second environmental state E2 (e.g. Figure 1The capacitance change of the touch plate (in the middle); ΔC trace1-E1-E2 The capacitance change value of the detection channel trace 1 is measured when the environment changes from the first environmental state E1 to the second environmental state E2.

[0071] Step S5: Determine the compensation coefficient based on the capacitance change values ​​of the detection channel and the bypass channel. This improves calculation speed while ensuring the accuracy of the compensation coefficient.

[0072] In some possible embodiments, the compensation coefficient can be determined based on the ratio of the capacitance measurement change of the detection channel to the capacitance measurement change of the bypass channel.

[0073] Compensation coefficient K = (Change in capacitance measurement of the detection channel / Change in capacitance measurement of the bypass channel) = ΔC sensor-E1-E2 / ΔC trace2-E1-E2 (11)

[0074] Step S6: Based on the compensation coefficient and the capacitance change value of the bypass channel, the third capacitance measurement value is compensated to determine the compensated capacitance measurement value of the detection channel. By compensating the third capacitance measurement value, capacitance changes caused by environmental variations can be corrected, improving capacitance detection accuracy and avoiding misjudgments.

[0075] Figure 5 A flowchart illustrating the determination of the capacitance measurement value of the compensated detection channel according to some embodiments of this application is shown below. Figure 5 This section details the steps for determining the capacitance measurement value of the compensated detection channel.

[0076] Step S61: Determine the compensation value based on the product of the compensation coefficient and the capacitance change value of the bypass channel.

[0077] That is, the compensation value C comp = Compensation coefficient × Change in capacitance of bypass channel = K × ΔC trace2-E1-E2 (12)

[0078] Step S62: Based on the compensation value, compensate the third capacitance measurement value to determine the compensated capacitance measurement value of the detection channel. This allows for more accurate compensation of capacitance changes caused by environmental variations, improving capacitance detection accuracy and avoiding misjudgments.

[0079] In some possible embodiments, the compensated capacitance measurement of the detection channel can be determined by the difference between the third capacitance measurement and the compensated value.

[0080] From formulas (11) and (12), we know that the capacitance measurement value of the compensated detection channel = the third capacitance measurement value - the compensation value = C sensor-E2-M1 -Ccomp =C sensor-E2-M1 -K×ΔC trace2-E1-E2 =C sensor-E2-M1 -ΔC sensor-E1-E2 / ΔC trace2-E1-E2 ×ΔC trace2-E1-E2 =C sensor-E2-M1 -ΔC sensor-E1-E2 =C sensor-E1-M1

[0081] As can be seen from the above formula, the third capacitance measurement value, after compensation, is equal to the first capacitance measurement value. This can correct the parasitic capacitance changes caused by environmental changes, improve the accuracy of touch capacitance measurement, ensure capacitance detection accuracy, and avoid misjudgment.

[0082] In addition to the method for determining the capacitance measurement value of the compensated detection channel in the above embodiments, this application also provides a method for determining the capacitance measurement value of the compensated detection channel, wherein the capacitance measurement value of the compensated detection channel is a function of the first capacitance measurement value and the second capacitance measurement value, that is, the capacitance measurement value of the compensated detection channel = f(C sensor-E1-M1 C sensor-E1-M2 ).

[0083] In some possible embodiments, the compensated capacitance measurement value of the detection channel satisfies a linear relationship with the first capacitance measurement value and the second capacitance measurement value, that is, the compensated capacitance measurement value of the detection channel = K1 × C sensor-E1-M1 -K2×C sensor-E1-M2 = (K1-K2)×C x-E1-M1 +(K1-K2)×C trace1-E1-M1 -K2×C trace2-E1-M1 (13)

[0084] In formula (13), K1 is the first compensation coefficient; K2 is the second compensation coefficient.

[0085] In the capacitor to be tested, the capacitance is 400 (e.g.) Figure 1 When the change in capacitance of the touch plate in the circuit with environmental factors (such as temperature) is approximately proportional to the change in capacitance of detection channel trace 1 and bypass channel trace 2 with environmental factors (such as temperature), the compensated capacitance measurement value of the detection channel can be determined by selecting appropriate first and second compensation coefficients.

[0086] Figure 6This diagram illustrates a block diagram of a capacitance detection device according to some embodiments of the present application. The capacitance detection device 100 includes: a capacitance detection sensor 110, a bypass capacitance sensor 120, and a digital processing unit 130. The capacitance detection sensor 110 is used to acquire a first capacitance measurement value of a detection channel in a first operating mode under a first environmental state and a third capacitance measurement value in the same first operating mode under a second environmental state.

[0087] The bypass capacitance sensor 120 is used to acquire the second capacitance measurement value of the detection channel in the second working mode under the first environmental state and the fourth capacitance measurement value in the second working mode under the second environmental state.

[0088] The digital processing unit 130 is configured to determine the capacitance measurement change value of the bypass channel based on the difference between the second capacitance measurement value and the first capacitance measurement value, and the difference between the fourth capacitance measurement value and the third capacitance measurement value; determine the capacitance measurement change value of the detection channel based on the first capacitance measurement value and the third capacitance measurement value; and determine the compensated capacitance measurement value of the detection channel based on the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel.

[0089] Figure 7 This diagram illustrates a block diagram of a System-on-Chip (SoC) according to some embodiments of this application. Figure 7 In the diagram, similar components share the same reference numerals. Additionally, dashed boxes are an optional feature for more advanced SoCs. Figure 7 In this embodiment, SoC 1500 includes: an interconnect unit 1550 coupled to an application processor 1515; a system proxy unit 1570; a bus controller unit 1580; an integrated memory controller unit 1540; a group or one or more coprocessors 1520, which may include integrated graphics logic, an image processor, an audio processor, and a video processor; a static random access memory (SRAM) unit 1530; and a direct memory access (DMA) unit 1560. In one embodiment, the coprocessor 1520 includes a dedicated processor, such as, for example, a network or communication processor, a compression engine, a GPGPU, a high-throughput MIC processor, or an embedded processor, etc.

[0090] The capacitance detection method and capacitance detection device provided in this application can correct capacitance changes caused by environmental changes, thereby ensuring capacitance detection accuracy and avoiding misjudgment.

[0091] The various embodiments of the mechanisms disclosed in this application can be implemented in hardware, software, firmware, or a combination of these implementation methods. Embodiments of this application can be implemented as computer programs or program code executable on a programmable system, the programmable system including at least one processor, a storage system (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device.

[0092] Program code can be applied to input instructions to execute the functions described in this application and generate output information. The output information can be applied to one or more output devices in a known manner. For the purposes of this application, the processing system includes any system having a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application-specific integrated circuit (ASIC), or a microprocessor.

[0093] The program code can be implemented using a high-level procedural language or an object-oriented programming language to communicate with the processing system. Assembly language or machine language can also be used when needed. In fact, the mechanisms described in this application are not limited to any particular programming language. In either case, the language can be a compiled language or an interpreted language.

[0094] In some cases, the disclosed embodiments may be implemented in hardware, firmware, software, or any combination thereof. The disclosed embodiments may also be implemented as instructions carried or stored thereon on one or more temporary or non-temporary machine-readable (e.g., computer-readable) storage media, which may be read and executed by one or more processors. For example, the instructions may be distributed via a network or through other computer-readable media. Therefore, machine-readable media may include any mechanism for storing or transmitting information in a machine-readable (e.g., computer-readable) form, including but not limited to floppy disks, optical disks, CD-ROMs, magneto-optical disks, read-only memory (ROM), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic cards or optical cards, flash memory, or tangible machine-readable storage for transmitting information (e.g., carrier waves, infrared signals, digital signals, etc.) using the Internet in the form of electrical, optical, acoustic, or other propagation signals. Therefore, machine-readable media include any type of machine-readable medium suitable for storing or transmitting electronic instructions or information in a machine-readable (e.g., computer-readable) form.

[0095] In the accompanying drawings, some structural or methodological features may be shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be necessary. Rather, in some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. Furthermore, the inclusion of structural or methodological features in a particular figure does not imply that such features are required in all embodiments, and in some embodiments, these features may be omitted or may be combined with other features.

[0096] It should be noted that all units / modules mentioned in the device embodiments of this application are logical units / modules. Physically, a logical unit / module can be a physical unit / module, a part of a physical unit / module, or a combination of multiple physical units / modules. The physical implementation of these logical units / modules themselves is not the most important factor; the combination of functions implemented by these logical units / modules is the key to solving the technical problems proposed in this application. Furthermore, to highlight the innovative aspects of this application, the above-described device embodiments of this application have not introduced units / modules that are not closely related to solving the technical problems proposed in this application. This does not mean that the above-described device embodiments do not contain other units / modules.

[0097] It should be noted that in the examples and description of this patent, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0098] All methods and implementations of this application can be implemented in the form of software, magnetic files, firmware, etc.

[0099] Program code can be applied to input instructions to perform the functions described herein and generate output information. The output information can be applied to one or more output devices in a known manner. For the purposes of this application, the processing system includes any system having a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application-specific integrated circuit (ASIC), or a microprocessor.

[0100] The program code can be implemented using a high-level procedural language or an object-oriented programming language to communicate with the processing system. Assembly language or machine language can also be used when needed. In fact, the mechanisms described in this paper are not limited to any particular programming language. In either case, the language can be a compiled language or an interpreted language.

[0101] One or more aspects of at least one embodiment can be implemented by representational instructions stored on a computer-readable storage medium, the instructions representing various logics in a processor, which, when read by a machine, cause the machine to create logic for performing the techniques described herein. These representations, referred to as “IP Cores,” can be stored on tangible computer-readable storage media and provided to multiple customers or production facilities for loading into manufacturing machines that actually manufacture the logic or processor.

[0102] In some cases, an instruction translator can be used to translate instructions from a source instruction set to a target instruction set. For example, an instruction translator can transform (e.g., using static binary transformation, including dynamically compiled dynamic binary transformation), morph, emulate, or otherwise translate instructions into one or more other instructions that will be processed by the IP core. Instruction translators can be implemented in software, hardware, firmware, or a combination thereof. Instruction translators can be on-processor, off-processor, or partially on-processor and partially off-processor.

[0103] Although this application has been illustrated and described with reference to certain preferred embodiments thereof, those skilled in the art should understand that various changes in form and detail may be made thereto without departing from the spirit and scope of this application.

Claims

1. A capacitance detection method for a capacitance detection device, characterized by, The method comprises: obtaining a first capacitance measurement value of a detection channel in a first working mode in a first environment state, and a second capacitance measurement value of the detection channel in a second working mode in the first environment state, wherein the first working mode is that the detection channel and a bypass channel are in a disconnected state; the second working mode is that the detection channel and the bypass channel are in a connected state; the detection channel comprises a detection channel trace, one end of the detection channel trace is connected with the capacitance detection device, and the other end of the detection channel trace is connected with a to-be-detected capacitance; the bypass channel comprises a bypass channel trace, one end of the bypass channel trace is connected with the capacitance detection device, and the other end of the bypass channel trace is floating; obtaining a third capacitance measurement value of the detection channel in the first working mode in a second environment state, and a fourth capacitance measurement value of the detection channel in the second working mode in the second environment state, wherein the second environment state is different from the first environment state in an environmental parameter; determining a capacitance measurement change value of the bypass channel according to a difference between the second capacitance measurement value and the first capacitance measurement value, and a difference between the fourth capacitance measurement value and the third capacitance measurement value; determining a capacitance measurement change value of the detection channel according to the first capacitance measurement value and the third capacitance measurement value; determining a compensated capacitance measurement value of the detection channel according to the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel.

2. The method of claim 1, wherein, The method comprises: determining a first capacitance measurement difference value as a difference between the second capacitance measurement value and the first capacitance measurement value, and determining a second capacitance measurement difference value as a difference between the fourth capacitance measurement value and the third capacitance measurement value; determining the capacitance measurement change value of the bypass channel according to the first capacitance measurement difference value and the second capacitance measurement difference value.

3. The method of claim 2, wherein, The method comprises: determining the capacitance measurement change value of the bypass channel according to a difference between the second capacitance measurement difference value and the first capacitance measurement difference value.

4. The method of claim 1, wherein, The method comprises: determining the capacitance measurement change value of the detection channel according to a difference between the third capacitance measurement value and the first capacitance measurement value.

5. The method of claim 1, wherein, The method comprises: determining a compensation coefficient according to a ratio of the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel; determining the compensated capacitance measurement value of the detection channel according to a product of the compensation coefficient and the capacitance measurement change value of the bypass channel.

6. The method of claim 5, wherein, determining a compensated capacitance measurement value of the detection channel according to a product of the compensation coefficient and a capacitance measurement change value of the bypass channel, including: determining a compensated capacitance measurement value of the detection channel according to a difference between the third capacitance measurement value and the product.

7. A capacitance detection device, characterized by, including: a detection capacitance sensor for obtaining a first capacitance measurement value of a detection channel in a first working mode in a first environmental state and a third capacitance measurement value in the first working mode in a second environmental state; wherein the first working mode is that the detection channel and a bypass channel are in a disconnected state; the second working mode is that the detection channel and the bypass channel are in a connected state; the detection channel includes a detection channel trace, one end of the detection channel trace is connected with the capacitance detection device, the other end of the detection channel trace is connected with a to-be-detected capacitance; the bypass channel includes a bypass channel trace, one end of the bypass channel trace is connected with the capacitance detection device, the other end of the bypass channel trace is floating; a bypass capacitance sensor for obtaining a second capacitance measurement value of the detection channel in a second working mode in the first environmental state and a fourth capacitance measurement value in the second working mode in the second environmental state; a digital processing unit for determining a capacitance measurement change value of the bypass channel according to a difference between the second capacitance measurement value and the first capacitance measurement value and a difference between the fourth capacitance measurement value and the third capacitance measurement value, determining a capacitance measurement change value of the detection channel according to the first capacitance measurement value and the third capacitance measurement value, and determining a compensated capacitance measurement value of the detection channel according to the capacitance measurement change value of the detection channel and the capacitance measurement change value of the bypass channel.

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