Capacitive sensing device operation method

Abstract

The present invention relates to a method for operating a capacitive sensing device, which includes: calculating a change in the detection data compared to the detection data received in the previous data frame; performing a comparison operation based on the detection data and a stored baseline value to determine whether a proximity event occurs. When a proximity event occurs, a pair of proximity baseline value update procedures are selected to update the baseline value based on the range of the change, so that the problem of the capacitive sensing device being unable to update the baseline value in a timely manner and possibly misjudging the capacitive sensing device can be effectively avoided when an object is close to the capacitive sensing device for a long time.

Description

Technical Field

[0001] The present invention relates to an operating method of a sensing device, and more particularly to an operating method for updating a baseline value of a capacitance sensing device in real time. Background Art

[0002] Many electronic devices on the market are equipped with proximity sensors, which are used to detect whether an object is close to the electronic device, so that the electronic device can make corresponding judgments or controls. It is common to use a light sensing device to form a proximity sensor. However, the light sensor relies on the light emitting component to emit light and measures the intensity of the received reflected light to determine whether the object is close. Therefore, it can only sense objects in the light emitting direction of the light emitting component, which is still limited in application.

[0003] Alternatively, a proximity sensor can be constructed through a capacitive sensing device. The principle is to determine whether the user's object is close to the electronic device based on the capacitance sensed by a sensing electrode when the object is close to the capacitive sensing device. In this way, not only can objects approaching the electronic device from all directions be sensed, but since the dielectric constants of the human body and other materials are different, the proximity sensor constructed by the capacitive sensing device can also distinguish whether the person approaching the electronic device is a human body. Therefore, if the user approaches the electronic device, the transmission power of the electronic device's radio frequency circuit can be reduced to control the specific absorption rate (SAR) within the specification to avoid affecting human health.

[0004] Generally speaking, a capacitive sensing device will compare the capacitance sensed by the sensing electrode with a baseline value (Baseline) to determine whether a proximity event has occurred. As environmental conditions such as temperature and humidity change, the capacitance sensed by the sensing electrode will naturally be different, so the baseline value should be dynamically adjusted with environmental conditions to ensure that the capacitive sensing device can correctly determine whether an object is approaching. In the prior art, the method of adjusting the baseline value generally uses the capacitance sensed by the sensing electrode when no proximity event occurs to update the baseline value; conversely, in the case of a proximity event, the prior art will determine that the capacitance sensed by the sensing electrode is mainly due to the proximity of an object, and therefore will completely or partially freeze the update of the baseline value when a proximity event occurs.

[0005] However, when an object is close to the capacitive sensing device for a long time, the above-mentioned prior art will fail to update the baseline value in a timely manner, which may cause the capacitive sensing device to misjudge and fail to correctly exit the proximity event or fail to judge the occurrence of the proximity event again. For example, when a user holds the electronic device close to the face for a continuous call and the surrounding environment changes drastically (such as walking from a hot outdoor environment to an air-conditioned room), the prior art will completely or partially freeze the update of the baseline value during this process, which may cause the capacitive sensing device to misjudge in the future.

[0006] Based on the above problems, the present invention provides an operation method for updating the baseline value of a capacitance sensing device in real time, which can improve the matching degree between the baseline value of the capacitance sensing device and the environmental conditions, so as to further increase the accuracy of determining proximity events. Summary of the invention

[0007] An object of the present invention is to provide an operating method of a capacitive sensing device, which can continuously update the baseline value using several proximity baseline value update procedures when a proximity event occurs, so as to improve the matching degree between the baseline value of the capacitive sensing device and the environmental conditions, thereby effectively increasing the judgment accuracy of the proximity event.

[0008] The present invention includes a capacitance sensing device operation method, which is implemented by a signal processing circuit, a baseline processing circuit and a proximity sensing circuit. The capacitance sensing device operation method includes: receiving a detection data by the signal processing circuit; calculating a change amount of the detection data compared with the detection data received in the previous data frame by the baseline processing circuit; performing a comparison operation by the proximity sensing circuit based on the detection data and a stored baseline value to determine whether a proximity event occurs; wherein, when a proximity event occurs, the baseline processing circuit selects a pair of proximity baseline value update procedures to update the baseline value according to the range of the change amount; when the proximity event does not occur, the baseline processing circuit updates the baseline value according to a non-proximity baseline value update; and the baseline processing circuit outputs the updated baseline value to the proximity sensing circuit.

[0009] The present invention includes another capacitance sensing device operation method, which is different from the above operation method in that when a proximity event does not occur, the baseline processing circuit selects one of several non-proximity baseline value update procedures to update the baseline value according to the range of the change. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 :It is a block diagram of a capacitive sensing device according to an embodiment of the present invention;

[0011] Figure 2 :It is an operation flow chart of an embodiment of the present invention; and

[0012] Figure 3 : It is an operation flow chart of another embodiment of the present invention.

[0013]

Figure number comparison

[0014] 10 Capacitive sensing device

[0015] 12 Sensing circuit

[0016] 14 Analog-to-digital conversion circuit

[0017] 16 Signal processing circuit

[0018] 18 Baseline processing circuit

[0019] 20 Proximity sensing circuit

[0020] V SEN Sensor signal

[0021] S D Digital signal

[0022] Raw detection data

[0023] B Baseline value

[0024] ProX Proximity Signal

[0025] S10 Steps for receiving detection data

[0026] S20 Calculation of change steps

[0027] S30 Proximity event determination steps

[0028] S40 Steps for determining the range of the change

[0029] S51 First proximity baseline value updating step

[0030] S52 Second proximity baseline value updating step

[0031] S60 Steps for determining the range of change

[0032] S70 Non-proximal baseline value update steps

[0033] S71 First non-proximal baseline value updating step

[0034] S72 Second non-proximal baseline value updating step DETAILED DESCRIPTION

[0035] In order to further understand and appreciate the structural features and effects of the present invention, a preferred embodiment and detailed description are provided as follows:

[0036] Certain words are used in the specification and claims to refer to specific components. However, those with ordinary knowledge in the technical field of the present invention should understand that manufacturers may use different terms to refer to the same component. Moreover, the specification and claims do not use the difference in name as a way to distinguish components, but use the overall technical difference of the components as the criterion for distinction. The word "including" mentioned throughout the specification and claims is an open term and should be interpreted as "including but not limited to". Furthermore, the word "coupled" here includes any direct and indirect connection means. Therefore, if the text describes a first device coupled to a second device, it means that the first device can be directly connected to the second device, or can be indirectly connected to the second device through other devices or other connection means.

[0037] In view of the fact that the existing capacitive sensing device will completely or partially freeze the update of the baseline value when a proximity event occurs, which may cause the conventional capacitive sensing device to misjudge, the present invention proposes a capacitive sensing device operation method to solve this problem. The following will further explain the characteristics of the capacitive sensing device operation method disclosed in the present invention and the capacitive sensing device architecture used therein:

[0038] First, please refer to FIG. 1, which is a block diagram of a capacitive sensing device 10 used in conjunction with the capacitive sensing device operating method of an embodiment of the present invention. As shown in the figure, the capacitive sensing device 10 includes a sensing circuit 12, an analog-to-digital conversion circuit 14, a signal processing circuit 16, a baseline processing circuit 18, and a proximity sensing circuit 20. The sensing circuit 12 is provided with a sensing electrode, which is equivalent to a capacitor, and its equivalent capacitance changes as an object approaches the sensing electrode. The object may be a human body, a desktop, or a stylus, etc. Therefore, the equivalent capacitance of the sensing electrode is used to sense whether the object is close to the capacitive sensing device. The sensing circuit 12 can input a signal to the sensing electrode to generate a sensing signal V corresponding to the equivalent capacitance of the sensing electrode. SEN .

[0039] The analog-to-digital conversion circuit 14 is coupled to the sensing circuit 12 and receives the sensing signal V SEN , and convert the analog sensing signal V SEN The output is a digital signal S D The signal processing circuit 16 is coupled to the analog-to-digital conversion circuit 14 to receive the digital signal S D , and according to the digital signal S D Generate a detection data Raw. In detail, the detection data Raw can be the digital signal S D , the digital signal S D Alternatively, the detection data Raw may also be a digital signal S generated by a plurality of sensing data frames (dataframe)D The average value or weighted average value is used, but the present invention is not limited thereto.

[0040] The baseline processing circuit 18 is coupled to the signal processing circuit 16 to receive the detection data Raw and adjust a baseline value B accordingly. The proximity sensing circuit 20 is coupled to the signal processing circuit 16 and the baseline processing circuit 18 to receive the detection data Raw and the baseline value B respectively, and then determines whether an object is close to the capacitive sensing device according to the comparison operation result of the detection data Raw and the baseline value B, and can generate a proximity signal ProX to indicate whether a proximity event occurs.

[0041] Please refer to FIG. 2 , after the capacitive sensing device 10 used in the capacitive sensing device operating method according to the embodiment of the present invention is described in detail below:

[0042] First, the baseline processing circuit 18 and the proximity sensing circuit 20 receive the detection data Raw[n] ( S10 ).

[0043] The baseline processing circuit 18 calculates the variation of the detection data Raw[n] (S20), that is, subtracts the detection data Raw[n-1] received in the previous data frame from the latest detection data Raw[n] to obtain a variation value Diff[n] as shown in the following formula:

[0044] Diff[n]=Raw[n]-Raw[n-1]

[0045] At this time, the baseline processing circuit 18 has not yet completed the update of the baseline value B, so the baseline value B[n-1] provided by the baseline processing circuit 18 in the previous data frame is stored in the proximity sensing circuit 20. The proximity sensing circuit 20 determines whether there is an object approaching the capacitive sensing device based on the comparison operation result of the detection data Raw[n] and the baseline value B[n-1] (S30). For example, generally speaking, the proximity sensing circuit 20 will default to a threshold value THD. When the difference between the detection data Raw[n] and the baseline value B[n-1] is greater than the threshold value THD (i.e., Raw[n]-B[n-1]>THD), it can be determined that an object is close to the capacitive sensing device, and then a proximity signal ProX of a first level (e.g., a high level) is output to indicate that a proximity event has occurred. Conversely, when the difference between the detection data Raw[n] and the baseline value B[n-1] is not greater than the threshold value (i.e., Raw[n]-B[n-1]≤THD), it is determined that no object is close to the capacitive sensing device, and then a proximity signal ProX of a second level (e.g., a low level) is output to indicate that no proximity event has occurred.

[0046] The operations of the baseline processing circuit 18 and the proximity sensing circuit 20 can be performed simultaneously or sequentially, and the order of operations is not limited. In addition, the proximity sensing circuit 20 can output the proximity signal ProX to the baseline processing circuit 18, so that the baseline processing circuit 18 can identify whether a proximity event occurs. However, the baseline processing circuit 18 can also directly obtain a signal from an electronic device provided for the capacitive sensing device 10 to identify whether a proximity event occurs, so the present invention is not limited to this.

[0047] Next, when a proximity event occurs, the baseline processing circuit 18 selects a pair of baseline values ​​B[n-1] from two or more proximity baseline value update procedures according to the range of the variation value Diff[n] generated by the above operation to update (S40). Specifically, in the present embodiment, a first proximity baseline value update S51 and a second proximity baseline value update S52 are included. The baseline processing circuit 18 is provided with a predetermined range [THp(+), THp(-)], wherein the upper threshold value THp(+) is greater than the lower threshold value THp(-), the upper threshold value THp(+) is generally a positive number, and the lower threshold value THp(-) is generally a negative value, and the size of the upper and lower threshold values ​​can be adjusted according to actual needs after experimental statistics. The baseline processing circuit 18 determines whether to use the first proximity baseline value update S51 or the second proximity baseline value update S52 to update the baseline value B[n-1] according to whether the variation value Diff[n] falls within the predetermined range [THp(+), THp(-)].

[0048] If the variation value Diff[n] falls within the predetermined range [THp(+), THp(-)] (i.e., THp(-)≤Diff[n]≤THp(+)), the baseline processing circuit 18 updates the baseline value B[n-1] with the first approximate baseline value update S51. The first approximate baseline value update S51 can be shown as follows:

[0049] B[n]=B[n-1]+β×Diff[n]

[0050] Since the variation value Diff[n] falls within the predetermined range, the variation of the detected data can be considered to be mainly caused by environmental conditions, so the coefficient β should be set larger and can be close to 1 in some embodiments.

[0051] On the contrary, if the variation value Diff[n] exceeds the predetermined range [THp(+), THp(-)] (i.e., THp(-)>Diff[n]; or Diff[n]>THp(+)), the baseline processing circuit 18 updates the baseline value B[n-1] with the second proximate baseline value update S52. The second proximate baseline value update S52 can be shown as follows:

[0052] B[n]=Gp×Raw[n]+(1-Gp)×Diff[n]

[0053] Since the change value Diff[n] has exceeded the predetermined range at this time, the change of the detection data can be regarded as caused by the environmental conditions and the proximity of the object. By controlling the size of an adjustment coefficient Gp, the influence of the detection data Raw[n] on the updated baseline value B[n] can be controlled. A person with ordinary knowledge in the art can know from the above description that in some embodiments of the present invention, the baseline value B[n-1] can be updated by the second close baseline value update S52 when the change value Diff[n] is less than the lower threshold value THp(-), and the baseline value B[n-1] can be updated by a third close baseline value update when the change value Diff[n] is greater than the upper threshold value THp(+). Therefore, when a proximity event occurs, the present invention allows the baseline processing circuit to select a pair of baseline values ​​from several close baseline value update procedures according to the range of the change value generated by the above operation, and is not limited to the first and second close baseline value updates S51 and S52 listed in this embodiment.

[0054] On the other hand, when the proximity event does not occur, the baseline processing circuit 18 updates the baseline value B[n-1] according to a non-proximity baseline value update S70. The non-proximity baseline value update S70 can be shown as follows:

[0055] B[n]=Gn×Raw[n]+(1-Gn)×Diff[n]

[0056] At this time, no proximity event has occurred. Although the change in the detection data can be considered to be mainly caused by environmental conditions, there may be many causes of noise in the environment, which may be different from environmental conditions such as temperature or humidity, which will have a continuous and consistent impact on the detection data Raw[n]. Therefore, the impact of the detection data Raw[n] on the updated baseline value B[n] can still be controlled by controlling the size of an adjustment coefficient Gn. Among them, the adjustment coefficient Gn can be preferably designed between 1 / 2 and 1 / 256, and the adjustment coefficient Gn is preferably greater than the adjustment coefficient Gp of the second proximity baseline value update S52.

[0057] After completing the first proximity baseline value update S51, the second proximity baseline value update S52 or the non-proximity baseline value update S70, the baseline processing circuit 18 outputs the updated baseline value B[n] to the proximity sensing circuit 20 so that the proximity sensing circuit 20 can determine whether there is an object approaching the capacitive sensing device in the next data frame.

[0058] In summary, by using the capacitive sensing device operating method of the above embodiment of the present invention, when a proximity event occurs, a pair of baseline values ​​can be selected from several proximity baseline value update procedures according to the range of the change amount of the detection data. Accordingly, the capacitive sensing device operating method of the embodiment of the present invention does not need to freeze the update of the baseline value, and can effectively avoid the problem that the capacitive sensing device may misjudge due to the inability to update the baseline value in a timely manner when an object is close to the capacitive sensing device for a long time.

[0059] Among them, when the change amount of the detection data is small, the change of the detection data can be regarded as mainly caused by the environmental conditions, so a higher weight can be used to update the baseline value with the detection data, as shown in the example of the first proximity baseline value update S51; relatively, when the change amount of the detection data is large, the change of the detection data can be regarded as caused by both the environmental conditions and the object approaching, so a lower weight can be used to update the baseline value with the detection data, as shown in the example of the second proximity baseline value update S52. In this way, the operating method of the capacitive sensing device of the embodiment of the present invention can take into account the characteristics of updating the baseline value in real time, and will not excessively include the change of the detection data caused by the object approaching into the updated baseline value, so it can effectively improve the matching degree between the baseline value of the capacitive sensing device and the environmental conditions, so as to further increase the accuracy of the judgment of the proximity event.

[0060] Please refer to FIG. 3 for another embodiment of the capacitive sensing device operation method of the present invention. The difference from the above embodiment is that when the proximity event does not occur, the baseline processing circuit 18 still selects a pair of baseline values ​​B[n-1] from two or more non-proximity baseline value update procedures according to the range of the change value Diff[n] generated by the above operation to update (S60). In detail, the present embodiment includes a first non-proximity baseline value update S71 and a second non-proximity baseline value update S72. The baseline processing circuit 18 is provided with a predetermined range [THn(+), THn(-)], wherein the upper threshold value THp(+) is greater than the lower threshold value THp(-), the upper threshold value THp(+) is generally a positive number, and the lower threshold value THp(-) is generally a negative value, and the size of the upper and lower threshold values ​​can be adjusted according to actual needs after experimental statistics. The baseline processing circuit 18 determines whether to use the first non-proximal baseline value update S71 or the second non-proximal baseline value update S72 to update the baseline value B[n-1] according to whether the variation value Diff[n] falls within the predetermined range [THn(+), THn(-)].

[0061] If the variation value Diff[n] falls within the predetermined range [THn(+), THn(-)] (i.e., THn(-)≤Diff[n]≤THn(+)), the baseline processing circuit 18 updates the baseline value B[n-1] with a first non-proximal baseline value update S71. The first non-proximal baseline value update S71 may be similar to the aforementioned non-proximal baseline value update S70, as shown in the following formula:

[0062] B[n]=Gn×Raw[n]+(1-Gn)×Diff[n]

[0063] The adjustment coefficient Gn can also be preferably designed to be between 1 / 2 and 1 / 256. By controlling the size of the adjustment coefficient Gn, unnecessary noise in the environment can be properly filtered out.

[0064] On the contrary, if the variation value Diff[n] exceeds the predetermined range [THn(+), THn(-)] (i.e., THn(-)>Diff[n]; or Diff[n]>THn(+)), the baseline processing circuit 18 updates with a second non-proximal baseline value update S72. The second non-proximal baseline value update S72 can be shown as follows:

[0065] B[n]=B[n-1]+α×Diff[n]

[0066] Since the variation value Diff[n] has exceeded the predetermined range at this time, although the proximity sensing circuit 20 determines that no proximity event has occurred, the variation of the detection data with an excessive amplitude can be regarded as not mainly caused by environmental conditions, so the coefficient α can be close to 0. A person skilled in the art can understand from the above description that in some embodiments of the present invention, the baseline value B[n-1] can be updated by a second non-proximity baseline value update S72 when the variation value Diff[n] is less than the lower threshold value THn(-), and the baseline value B[n-1] can be updated by a third non-proximity baseline value update when the variation value Diff[n] is greater than the upper threshold value THn(+). Therefore, when the proximity event has not occurred, the present invention can allow the baseline processing circuit to select a pair of baseline values ​​from several non-proximity baseline value update procedures according to the range of the variation value generated by the above operation, and is not limited to the first and second non-proximity baseline value updates S71 and S72 listed in this embodiment.

[0067] It is worth noting that in both the first proximal baseline value update S51 and the first non-proximal baseline value update S71, the change of the detected data is considered to be mainly caused by environmental conditions, so the first proximal baseline value update S51 method described above can also be applied to the first non-proximal baseline value update S71; similarly, the first non-proximal baseline value update S71 described above can also be applied to the first proximal baseline value update S51. On the other hand, in the second proximal baseline value update S52 and the second non-proximal baseline value update S72, the change of the detected data is considered not to be caused only by environmental conditions, so the second proximal baseline value update S52 method described above can also be applied to the second non-proximal baseline value update S72; similarly, the second non-proximal baseline value update S72 described above can also be applied to the second proximal baseline value update S52. In addition, although the filtering operations listed in the aforementioned embodiments of the present invention are all infinite impulse response filters (IIR), the present invention can also be replaced with finite impulse response filters (FIR) operations or other noise reduction algorithms depending on the application scenario.

[0068] Compared to the conventional capacitive sensing device which completely or partially freezes the updating of the baseline value when a proximity event occurs, which may result in the possibility of misjudgment of the conventional capacitive sensing device, the present invention provides an operating method for updating the baseline value of a capacitive sensing device in real time, which can continuously update the baseline value using several proximity baseline value updating procedures when a proximity event occurs, so as to improve the matching degree between the baseline value of the capacitive sensing device and the environmental conditions, thereby further increasing the judgment accuracy of the proximity event.

[0069] The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent changes and modifications to the shape, structure, characteristics and spirit described in the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for operating a capacitive sensing device, characterized in that: The method is implemented by a signal processing circuit, a baseline processing circuit and a proximity sensing circuit. The method comprises: The signal processing circuit receives a detection data; Calculating a change in the detection data compared to the detection data received in the previous data frame using the baseline processing circuit; The proximity sensing circuit performs a comparison operation based on the detection data and a stored baseline value to determine whether a proximity event occurs; Wherein, when a proximity event occurs, the baseline processing circuit selects one of several proximity baseline value update procedures to update the baseline value according to the range of the variation, wherein the proximity baseline value update procedure includes a first proximity baseline value update and a second proximity baseline value update, and the baseline processing circuit is provided with a predetermined range. If the variation falls within the predetermined range, the baseline processing circuit updates the baseline value with the first proximity baseline value update; if the variation exceeds the predetermined range, the baseline processing circuit updates the baseline value with the second proximity baseline value update; The baseline processing circuit updates the baseline value according to a non-proximity baseline value update when a proximity event does not occur; and The baseline processing circuit outputs the updated baseline value to the proximity sensing circuit.

2. The method for operating a capacitance sensing device according to claim 1, wherein: The first close baseline value is updated as shown below: B[n]=B[n-1]+β×Diff[n] Wherein B[n] is the updated baseline value, B[n-1] is the baseline value stored by the proximity sensing circuit, Diff[n] is the change, and β is a coefficient.

3. The method for operating a capacitance sensing device according to claim 1, wherein: The second close baseline value is updated as shown in the following formula: B[n]=Gp×Raw[n]+(1-Gp)×Diff[n] Wherein B[n] is the updated baseline value, Raw[n] is the detection data, Diff[n] is the change amount, and Gp is ​​an adjustment coefficient.

4. The method for operating a capacitance sensing device as claimed in claim 3, wherein: The non-proximal baseline value is updated as follows: B[n]=Gn×Raw[n]+(1-Gn)×Diff[n] Wherein, Gn is another adjustment coefficient, and the other adjustment coefficient Gn is greater than the adjustment coefficient Gp updated by the second proximate baseline value.

5. The method for operating a capacitance sensing device as claimed in claim 4, wherein: in, The other adjustment coefficient Gn is designed to be between 1 / 2 and 1 / 256.

6. A method for operating a capacitive sensing device, characterized in that: The method is implemented by a signal processing circuit, a baseline processing circuit and a proximity sensing circuit. The method comprises: The signal processing circuit receives a detection data; Calculating a change in the detection data compared to the detection data received in the previous data frame using the baseline processing circuit; The proximity sensing circuit performs a comparison operation based on the detection data and a stored baseline value to determine whether a proximity event occurs; Wherein, when a proximity event occurs, the baseline processing circuit selects one of several proximity baseline value update procedures to update the baseline value according to the range of the variation, wherein the proximity baseline value update procedure includes a first proximity baseline value update and a second proximity baseline value update, and the baseline processing circuit is provided with a predetermined range. If the variation falls within the predetermined range, the baseline processing circuit updates the baseline value with the first proximity baseline value update; if the variation exceeds the predetermined range, the baseline processing circuit updates the baseline value with the second proximity baseline value update; When the proximity event does not occur, the baseline processing circuit selects one of several non-proximity baseline value updating procedures to update the baseline value according to the range of the change amount; and The baseline processing circuit outputs the updated baseline value to the proximity sensing circuit.

7. The method for operating a capacitance sensing device according to claim 6, wherein: The non-proximal baseline value update procedure includes a first non-proximal baseline value update and a second non-proximal baseline value update. The baseline processing circuit is provided with another predetermined range. If the change amount falls within the other predetermined range, the baseline processing circuit updates the baseline value with the first non-proximal baseline value update; if the change amount exceeds the other predetermined range, the baseline processing circuit updates the baseline value with the second non-proximal baseline value update.

8. The method for operating a capacitance sensing device as claimed in claim 7, wherein: The first close baseline value is updated as shown below: B[n]=B[n-1]+β×Diff[n] Wherein B[n] is the updated baseline value, B[n-1] is the baseline value stored by the proximity sensing circuit, Diff[n] is the change, and β is a coefficient.

9. The method for operating a capacitance sensing device according to claim 7, wherein: The second close baseline value is updated as shown in the following formula: B[n]=Gp×Raw[n]+(1-Gp)×Diff[n] Wherein B[n] is the updated baseline value, Raw[n] is the detection data, Diff[n] is the change amount, and Gp is ​​an adjustment coefficient.

10. The method for operating a capacitance sensing device according to claim 9, wherein: The first non-proximal baseline value is updated as follows: B[n]=Gn×Raw[n]+(1-Gn)×Diff[n] Wherein, Gn is another adjustment coefficient, and the other adjustment coefficient Gn is greater than the adjustment coefficient Gp updated by the second proximate baseline value.

11. The method for operating a capacitance sensing device according to claim 10, wherein: in, The other adjustment coefficient Gn is designed to be between 1 / 2 and 1 / 256.

12. The method for operating a capacitance sensing device according to claim 7, wherein: The second non-proximal baseline value is updated as follows: B[n]=B[n-1]+α×Diff[n] Wherein B[n] is the updated baseline value, B[n-1] is the baseline value stored by the proximity sensing circuit, Diff[n] is the change, and α is a coefficient.

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