Sensing device

Abstract

The invention relates to a sensing device which obtains a first filtering signal through a first filtering element according to a sensing reference signal corresponding to a sensing signal and obtains a second filtering signal through a second filtering element according to an analog reference signal. And a noise compensation signal is generated according to the first filtering signal and the second filtering signal, so that an analog front-end circuit receives the sensing signal and the noise compensation signal, and the noise of the sensing signal can be reduced by compensating the sensing signal.

Description

Technical Field

[0001] The present invention relates to an electronic device, in particular to a sensing device which compensates a sensing signal, thereby reducing a noise of the sensing signal. Background Art

[0002] With the development of consumer electronic devices, consumer electronic devices will have a variety of sensing functions, such as touch sensing and proximity sensing. Generally, consumer electronic devices with touch sensing functions use a touch panel with a display panel to provide users with an input signal to the consumer electronic device through the touch sensing of the touch panel on the display screen of the display panel. Therefore, the display panel matched with the touch panel may include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), electroluminescent displays (ELDs), electrophoretic displays (EPDs), and organic light-emitting devices (OLEDs) and other display devices. The touch panel allows the user to press or contact with the touch panel by means of fingers, pens, etc., so that the sensing device on the touch panel senses the user's touch position and generates corresponding input information in combination with the screen information.

[0003] In the circuit design of the sensing device, since most circuit elements nowadays are semiconductor elements, and with the changes in the process and even the materials, in the consumer electronic device, other circuit elements will cause the sensing device to be subjected to noise, or even interfere with the sensing result. For example, when the user operates the consumer electronic device with a touch device, and the multiple semiconductor switch elements connected between the display panel and the driving element are switched, these switches are usually affected by the difference between the voltage of the data line and the voltage output by the driver, resulting in the possibility of charge sharing between the various switch elements, thereby causing the display panel to generate noise to other circuit elements, or when data is transmitted between a system chip (SoC) of the consumer electronic device and a display device according to the MIPIDSI standard, a data channel stops for a period due to an idle period or a stop state of data transmission, thereby causing the display panel to generate power noise, or noise associated with data transmission, thereby affecting the sensing device on the consumer electronic device.

[0004] Based on the above problems, the present invention provides a sensing device, which is coupled to a sensing circuit and an analog front-end circuit by a noise compensation circuit, and the noise compensation circuit generates a first filter signal according to a sensing reference signal corresponding to a sensing signal of the sensing circuit, and generates a second filter signal according to an analog reference signal, and generates a noise compensation signal according to the first and second filter signals. Therefore, the analog front end can receive the sensing signal and the noise compensation signal respectively, and compensate the sensing signal according to the noise compensation signal to reduce a noise of the sensing signal. Summary of the invention

[0005] An object of the present invention is to provide a sensing device, which reduces a noise of the sensing signal by setting a noise compensation circuit in the sensing device and generating a noise compensation signal, thereby inputting the noise compensation signal together with a sensing signal into an analog front-end circuit, so that the analog front-end circuit compensates the sensing signal according to the noise compensation signal.

[0006] In view of the above-mentioned purpose, the present invention provides a sensing device, which includes an analog front-end circuit, a sensing circuit and a noise compensation circuit, wherein the noise compensation circuit is respectively coupled to the sensing circuit and the analog front-end circuit, and the analog front-end circuit includes a first filtering element, a second filtering element and an operation unit. The first filtering element generates a first filtering signal according to a sensing reference signal corresponding to the sensing signal, and the second filtering element generates a second filtering signal according to an analog reference signal. Therefore, the operation unit generates a noise compensation signal according to the first filtering signal and the second filtering signal, and the analog front-end circuit compensates the sensing signal according to the noise compensation signal to reduce a noise of the sensing signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 :It is a block diagram of the sensing device of the present invention; Figure 2 : It is a schematic diagram of signal transmission of the sensing device of the first embodiment of the present invention; Figure 3A : It is a schematic diagram of signal transmission of a sensing device according to a second embodiment of the present invention; Figure 3B : It is a schematic diagram of signal transmission of a sensing device according to a third embodiment of the present invention; Figure 3C : It is a schematic diagram of signal transmission of a sensing device according to a fourth embodiment of the present invention; Figure 3D : It is a schematic diagram of signal transmission of a sensing device according to a fifth embodiment of the present invention; Figure 4A : It is a schematic diagram of signal transmission of a sensing device according to a sixth embodiment of the present invention; Figure 4B :It is a first schematic diagram of a first bandpass filter element of the present invention; Figure 4C : It is a second schematic diagram of the first bandpass filter element of the present invention; Figure 4D : It is a third schematic diagram of the first bandpass filter element of the present invention; Figure 5 : It is a schematic diagram of signal transmission of a sensing device according to a seventh embodiment of the present invention; Figure 6 : It is a schematic diagram of signal transmission of a sensing device according to an eighth embodiment of the present invention; Figure 7 : It is a schematic diagram of signal transmission of a sensing device according to a ninth embodiment of the present invention; Fig. 8A : It is a schematic diagram of signal transmission of a sensing device according to the tenth embodiment of the present invention; Figure 8B :It is a first schematic diagram of the band-stop filter element of the present invention; Figure 8C :It is a second schematic diagram of the band-stop filter element of the present invention; Fig. 9 : It is a schematic diagram of signal transmission of a sensing device according to the eleventh embodiment of the present invention; Fig.10 : It is a schematic diagram of signal transmission of a sensing device according to a twelfth embodiment of the present invention; Fig.11 : It is a schematic diagram of signal transmission of a sensing device according to the thirteenth embodiment of the present invention; Fig.12 : It is a schematic diagram of signal transmission of a sensing device according to a fourteenth embodiment of the present invention; Fig.13 : It is a schematic diagram of signal transmission of a sensing device according to a fifteenth embodiment of the present invention; Fig.14 : It is a schematic diagram of signal transmission of a sensing device according to a sixteenth embodiment of the present invention; Fig.15 : It is a signal transmission schematic diagram of a sensing device according to a seventeenth embodiment of the present invention; Fig.16 : It is a schematic diagram of signal transmission of a sensing device according to the eighteenth embodiment of the present invention; Fig.17 : It is a schematic diagram of signal transmission of a sensing device according to the nineteenth embodiment of the present invention; Fig.18 : It is a schematic diagram of signal transmission of a sensing device according to the twentieth embodiment of the present invention; and Fig.19: It is a signal transmission schematic diagram of the sensing device according to the twenty-first embodiment of the present invention.

Figure number comparison

[0008] 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:

[0009] 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 the same component may be referred to by different nouns. Moreover, the specification and claims do not use the difference in name as a way to distinguish components, but use the difference in the overall technology 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.

[0010] In view of the problem that conventional sensing devices have to withstand noise during the signal processing process, the present invention proposes a sensing device, which generates a first filter signal according to a sensing reference signal corresponding to a sensing signal of a sensing circuit and generates a second filter signal according to an analog reference signal through a noise compensation circuit, thereby generating a noise compensation signal, so that an analog front-end circuit of the sensing device compensates the sensing signal according to the noise compensation signal, thereby allowing the present invention to reduce the noise borne during the signal processing process.

[0011] Hereinafter, the present invention will be described in detail by illustrating various embodiments of the present invention with reference to the drawings. However, the concept of the present invention may be embodied in many different forms and should not be construed as being limited to the exemplary embodiments described herein.

[0012] First, see Figure 1, which is a block diagram of the sensing device of the present invention. As shown in the figure, a sensing device 10 of the present embodiment includes an analog front-end circuit 12, a sensing circuit 14 and a noise compensation circuit 16. The sensing circuit 14 and the noise compensation circuit 16 are both coupled to the analog front-end circuit 12, and the noise compensation circuit 16 is further coupled to the sensing circuit 14. The sensing circuit 14 generates a sensing signal SS to the analog front-end circuit 12, and the noise compensation circuit 16 generates a noise compensation signal CS to the analog front-end circuit 12. The sensing signal SS includes a first noise N1, and the noise compensation signal CS includes a second noise N2. The analog front-end circuit 12 compensates the sensing signal SS according to the noise compensation signal CS, thereby eliminating the first noise N1 in the sensing signal SS, and an output signal OUT of the analog front-end device 12 presents a signal waveform with a slowed noise. Details are described below.

[0013] See also Figure 2 , which is a signal transmission schematic diagram of the first embodiment of the present invention. As shown in the figure, the sensing circuit 14 of the present embodiment includes a capacitive sensing element 142, and a corresponding sensing reference signal S1. The noise compensation circuit 16 of the present embodiment includes a first filter element 162, a second filter element 164 and an operation element 166, wherein the capacitive sensing element 142 is coupled to the analog front-end circuit 12 via a sensing end 102 of the sensing device 10, and a first end of the first filter element 162 is coupled to the capacitive sensing element 142 via a non-sensing end 104 of the sensing device 10 and receives the sensing reference signal S1. A second end of the first filter element 162 is coupled to the operation element 166, a first end of the second filter element 164 receives an analog reference signal S2, and a second end of the second filter element 164 is coupled to the operation element 166. In one embodiment, the operation element 166 can be coupled to the second end of the first filter element 162 and the second end of the second filter element 164. The potential of the analog reference signal S2 corresponds to the operating voltage of the analog front-end circuit 12, and the sensing reference signal S1 further corresponds to the noise received by the sensing device 10, for example, the noise from the display panel (not shown). The sensing device 10 can generate the corresponding noise compensation signal CS by means of the noise compensation circuit 16 and its first filter element 162 and the second filter element 164, which is used to compensate the first noise N1 of the sensing signal SS received by the analog front-end circuit 12, and maintain the operating voltage characteristics of the analog front-end circuit 12, thereby improving the signal-to-noise ratio (SNR) of the sensing circuit 14.

[0014] See also Figure 2The first filter element 162 generates a first filter signal FS1 according to the sensing reference signal S1, the second filter element 164 generates a second filter signal FS2 according to the analog reference signal S2, and the operation element 166 generates the noise compensation signal CS according to the first filter signal FS1 and the second filter signal FS2. Since the cutoff frequencies of the first filter element 162 and the second filter element 164 are different, the noise compensation signal CS generated by the operation element 166 according to the first filter signal FS1 and the second filter signal FS2 also corresponds to different cutoff frequencies. In this way, the analog front-end circuit 12 can eliminate the noise of the sensing signal SS according to the noise compensation signal CS, so that the output signal OUT generated by the analog front-end circuit 12 presents a noise slowdown.

[0015] In addition, the sensing circuit 14 of the present embodiment is further coupled to a first reference power supply NS, which supplies the sensing reference signal S1 to the sensing circuit 14. Therefore, the first end of the first filtering element 162 is coupled between the sensing circuit 14 and the first reference power supply NS, thereby obtaining the sensing reference signal S1 to generate the first filtering signal FS1; and the noise compensation circuit 16 of the present embodiment is further coupled to a second reference power supply RS, which supplies the analog reference signal S2 to the noise compensation circuit 16. Therefore, the first end of the second filtering element 164 is coupled to the second reference power supply RS, thereby obtaining the analog reference signal S2 to generate the second filtering signal FS2, wherein the first reference power supply NS and the second reference power supply RS are respectively coupled to the ground. Furthermore, the analog front-end circuit 12 of the present embodiment includes an amplifier circuit 122 as an example, but the present invention is not limited thereto. The analog front-end circuit 12 can be adjusted according to usage requirements, for example: a modulation circuit is further provided to modulate the bandwidth or the duty cycle, wherein the amplifier circuit 122 receives the sensing signal SS and the noise compensation signal CS. Since the first noise N1 of the sensing signal SS can be offset and compensated by the second noise N2 of the noise compensation signal CS, the first noise N1 is reduced, and therefore the signal waveform of the output signal OUT of the analog front-end circuit 12 is slower and smoother, thereby reducing the proportion of noise in the overall signal. Therefore, the present invention can improve the signal-to-noise ratio of the sensing signal SS.

[0016] like Figure 3AAs shown in the signal transmission diagram of the second embodiment of the present invention, it further reveals that the application embodiment of the first filter element 162 is a first high-pass filter element 162A, and the application embodiment of the second filter element 164 is a second low-pass filter element 164A. The cut-off frequency of the first high-pass filter element 162A is greater than the cut-off frequency of the second low-pass filter element 164A. For example, the cut-off frequency of the first high-pass filter element 162A is 10MHz, that is, it cuts off signals below 10MHz, and the cut-off frequency of the second low-pass filter element 164A is 1kHz, that is, it cuts off signals above 1kHz. In this embodiment, the noise compensation signal CS generated according to the first filter signal FS1 and the second filter signal FS2 is a high-frequency noise reference voltage signal, thereby eliminating the high-frequency noise of the sensing signal SS. At the same time, the operating voltage characteristics of the analog front-end circuit 12 can be maintained through the noise compensation signal CS.

[0017] like Figure 3B 1, a signal transmission schematic diagram of the third embodiment of the present invention further discloses that the first high-pass filter element 162A is implemented by using a filter capacitor 162A' for signal filtering, and the second low-pass filter element 164A is implemented by using a resistor 164A' for signal filtering. Therefore, a first end of the filter capacitor 162A' is coupled between the capacitive sensing element 142 and the first reference power source NS, a second end of the filter capacitor 162A' is coupled to the operational element 166, and a first end of the resistor 164A' is coupled to the operational element 166. The second reference power source RS is coupled to receive the analog reference signal S2. A second end of the resistor 164A' is coupled to the operation element 166. In an exemplary embodiment, the operation element 166 may be a second end of the filter capacitor 162A' coupled to the second end of the resistor 164A'. The equivalent circuit from the second reference power source RS to the operation element 166 is a low-pass filter element, and the equivalent circuit from the non-sensing end 104 to the operation element 166 is a high-pass filter element. The filtering method has been disclosed in Figure 2 and Figure 3A The embodiments of the present invention are described below and therefore will not be described in detail.

[0018] like Figure 3CAs shown, the signal transmission schematic diagram of the fourth embodiment of the present invention further reveals that the embodiment of the second low-pass filter element 164A is to adopt an operational amplifier 164A", wherein a positive input terminal of the operational amplifier 164A" is coupled to the analog reference signal S2, which is equivalent to the first terminal of the second low-pass filter element 164A being coupled to the second reference power supply RS and receiving the analog reference signal S2, and a negative input terminal of the operational amplifier 164A" is coupled to an output terminal of the operational amplifier 164A", thereby coupling the output terminal through the negative input terminal of the operational amplifier 164A", so that the negative input terminal and the output terminal of the operational amplifier 164A" are short-circuited to be used as a buffer element. In addition, the short-circuit coupling between the negative input terminal and the output terminal of the operational amplifier 164A" allows the operational amplifier 164A" to be equivalent to a low-pass filter element by adjusting the bandwidth when used as the buffer element, but the present invention is not limited to this. The operational amplifier 164A" can also be equivalent to a high-pass filter element by adjusting the bandwidth.

[0019] like Figure 3D FIG. 1 is a schematic diagram of signal transmission according to a fifth embodiment of the present invention, wherein Figure 3C and Figure 3D The difference is Figure 3D The embodiment further provides a first current conversion element 167 and a second current conversion element 168, whereby the first high-pass filter element 162A uses the filter capacitor 162A' and the first current conversion element 167, that is, correspondingly generates a first filter current FI1, which is different from the first filter signal FS1. Similarly, the second low-pass filter element 164A uses the operational amplifier 164A" and the second current conversion element 168, that is, correspondingly generates a second filter current FI2, which is different from the second filter signal FS2. Similarly, after receiving the first filter current FI1 and the second filter current FI2, the operational element 166 generates the noise compensation signal CS according to the first filter current FI1 and the second filter current FI2, and transmits it to the analog front-end circuit 12 to compensate the sensing signal SS.

[0020] In the above embodiment, the first filter element 162 and the second filter element 164 are respectively the first high-pass filter element 162A and the second low-pass filter element 164A. In the next embodiment, the first filter element 162 and the second filter element 164 are respectively the first band-pass filter element 162B and the second low-pass filter element 164A, as described in detail as follows:

[0021] See also Figure 4A , which is a signal transmission schematic diagram of the sixth embodiment of the present invention. Figure 3A and Figure 4A The difference is Figure 3AThe first filter element 162 and the second filter element 164 are respectively implemented as the first high-pass filter element 162A and the second low-pass filter element 164A. Figure 4A The first filter element 162 and the second filter element 164 of the embodiment are respectively using the first band-pass filter element 162B and the second low-pass filter element 164A. Moreover, the first high-pass filter element 162A has a cut-off frequency, the first band-pass filter element 162B has two cut-off frequencies, and the two cut-off frequencies of the first band-pass filter element 162B are greater than the cut-off frequency of the second low-pass filter element 164A. For example, the first band-pass filter element 162B is 1MHz and 3KHz, and the transmission signal with a pass frequency of 1MHz and 3KHz is passed, and the cut-off frequency of the second low-pass filter element 164A is 1KHz, so the two cut-off frequencies of the first band-pass filter element 162B are both higher than the cut-off frequency of the second low-pass filter element 164A. Thus, the frequency corresponding to the noise compensation signal CS of this embodiment is different from the noise compensation signal CS of the previous embodiment.

[0022] like FIG. 4B to FIG. 4D , which are the first schematic diagram to the third schematic diagram of the first bandpass filter element 162B, which disclose that the first bandpass filter element 162B includes a plurality of capacitors and a plurality of resistors, for example: a first capacitor C1, a second capacitor C2, a first resistor R1 and a second resistor R2, as shown in FIG. Figure 4B As shown, in the present embodiment, a first end of the first resistor R1 is coupled to a first end of the first band-pass filter element 162B, and a second end of the first resistor R1 is coupled to a first end of the first capacitor C1 and a first end of the second capacitor C2, and a second end of the first capacitor C1 is coupled to ground, a second end of the second capacitor C2 is coupled to a second end of the first band-pass filter element 162B, and coupled to a first end of the second resistor R2, and a second end of the second resistor R2 is coupled to ground.

[0023] like Figure 4C As shown, in the present embodiment, the first end of the first capacitor C1 is coupled to the first end of the first band-pass filter element 162B, the second end of the first capacitor C1 is coupled to the first end of the first resistor R1 and the first end of the second resistor R2, the second end of the first resistor R1 is coupled to the ground, the second end of the second resistor R2 is coupled to the second end of the first band-pass filter element 162B and the first end of the second capacitor C2, and the second end of the second capacitor C2 is coupled to the ground.

[0024] like Figure 4DAs shown, the embodiment of the first band-pass filter element 162B of the present embodiment further includes a first operational amplifier OP1, wherein the first end of the first capacitor C1 is coupled to the first end of the first band-pass filter element 162B, the second end of the first capacitor C1 is coupled to the first end of the first resistor R1, the second end of the first resistor R1 is coupled to a negative input end of the first operational amplifier OP1, the first end of the second resistor R2 and the first end of the second capacitor C2, the second end of the first band-pass filter element 162B is coupled to an output end of the first operational amplifier OP1, the second end of the second resistor R2 and the second end of the second capacitor C2, and a positive input end of the first operational amplifier OP1 is coupled to ground.

[0025] From the above FIG. 4B to FIG. 4D It can be known that the first bandpass filter element 162B can be implemented by the above three schematic diagrams.

[0026] See also Figure 5 , which is a signal transmission schematic diagram of the seventh embodiment of the present invention. Figure 4A and Figure 5 The difference is Figure 4A The first filter element 162 and the second filter element 164 are respectively implemented as the first band-pass filter element 162B and the second low-pass filter element 164A. Figure 5 The first filter element 162 and the second filter element 164 of the embodiment respectively adopt the first high-pass filter element 162A and a second band-pass filter element 164B. The first high-pass filter element 162A of the present embodiment is the same as the first high-pass filter element 162A of the first embodiment, and the second band-pass filter element 164B of the present embodiment is the same as the first band-pass filter element 162B of the sixth embodiment, so the detailed connection relationship between the first high-pass filter element 162A and the second band-pass filter element 164B of the present embodiment is not repeated. The first high-pass filter element 162A of the present embodiment generates the first filter signal FS1 according to the sensing reference signal S1, and the second band-pass filter element 164B generates the second filter signal FS2 according to the analog reference signal S2. The operation element 166 generates the noise compensation signal CS to the analog front-end circuit 12 according to the first filter signal FS1 and the second filter signal FS2.

[0027] like Figure 6, which is a schematic diagram of signal transmission of the eighth embodiment of the present invention. As shown in the figure, the first filter element 162 and the second filter element 164 of this embodiment are changed to use the first band-pass filter element 162B and a second band-pass filter element 164B, which are different from the first high-pass filter element 162A and a second band-pass filter element 164B of the previous embodiment. As shown in the figure, since the first band-pass filter element 162B and the second band-pass filter element 164B both include two cut-off frequencies, the two cut-off frequencies of the first band-pass filter element 162B are both greater than or both less than the two cut-off frequencies of the second band-pass filter element 164B. For example, the two cut-off frequencies of the first band-pass filter element 162B are 10 MHz and 1 MHz, i.e., signals with frequencies between 10 MHz and 1 MHz are allowed to pass through, and the two cut-off frequencies of the second band-pass filter element 164B are 3 KHz and 100 Hz, i.e., signals with frequencies between 3 KHz and 100 Hz are allowed to pass through, or the two cut-off frequencies of the second band-pass filter element 164B are 10 MHz and 1 MHz, i.e., signals with frequencies between 10 MHz and 1 MHz are allowed to pass through, and the two cut-off frequencies of the first band-pass filter element 162B are 3 KHz and 100 Hz, i.e., signals with frequencies between 3 KHz and 100 Hz are allowed to pass through. Thus, the operational element 166 generates the corresponding noise compensation signal CS according to the first filter signal FS1 and the second filter signal FS2 generated by the first bandpass filter element 162B and a second bandpass filter element 164B, which corresponds to the cutoff frequency of the first bandpass filter element 162B and a second bandpass filter element 164B.

[0028] like Figure 7 , which is a schematic diagram of signal transmission according to the ninth embodiment of the present invention. Figure 6 and Figure 7 The difference is Figure 6 An embodiment of the first filter element 162 is the first bandpass filter element 162B, Figure 7 The embodiment of the first filter element 162 is a first low-pass filter element 162C, especially the first low-pass filter element 162C and the second band-pass filter element 164B of this embodiment, equivalent to Figure 4A The first band-pass filter element 162B and the second low-pass filter element 164A are replaced with each other in the embodiment. Therefore, the cut-off frequency of the first low-pass filter element 162C of this embodiment is lower than the cut-off frequency of the second band-pass filter element 164B. The generation method of the noise compensation signal CS is equivalent to Figure 4A The embodiments of the present invention are described below and therefore will not be described in detail.

[0029] like Fig. 8A , which is a schematic diagram of signal transmission according to the tenth embodiment of the present invention. Figure 7 and Fig. 8A The difference is Figure 7 The embodiment of the first filter element 162 is to use the first low-pass filter element 162C, Fig. 8A An embodiment of the first filter element 162 is to use a first band-stop filter element 162D, which corresponds to two cut-off frequencies and blocks the signal between the two cut-off frequencies, that is, the first filter signal FS1 generated by the first band-stop filter element 162D is not a signal between the two cut-off frequencies, and the two cut-off frequencies of the second filter signal FS2 generated by the second band-pass filter element 164B are between the two cut-off frequencies of the first band-stop filter element 162D. For example: the two cut-off frequencies of the first band-stop filter element 162D are 3MHz and 10kHz, so the first band-stop filter element 162D blocks the signal with a frequency between 3MHz and 10kHz, that is, the first filter signal FS1 is a signal with a frequency greater than 3MHz and less than 10kHz, and the two cut-off frequencies of the second band-pass filter element 164B are 1MHz and 30kHz, that is, the second filter signal FS2 is a signal with a frequency between 1MHz and 30kHz. The noise compensation signal CS generated by the operational element 166 corresponds to the two cutoff frequencies of the first band-stop filter element 162D and the two cutoff frequencies of the second band-pass filter element 164B.

[0030] Further reading Figure 8B and Figure 8C , which are the first schematic diagram and the second schematic diagram of the first band-stop filter element 162D of the present invention, which disclose that the first band-stop filter element 162D includes a plurality of resistors and a plurality of capacitors, for example: Figure 8B As shown, the first band-stop filter element 162D includes a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a third resistor R3, a fourth resistor R4 and a fifth resistor R5. A first end of the third capacitor C3 and a first end of the third resistor R3 are coupled to a first end of the first band-stop filter element 162D, a second end of the third capacitor C3 is coupled to a first end of the fourth capacitor C4 and a first end of the fifth resistor R5, a second end of the fifth resistor R5 is coupled to ground, a second end of the third resistor R3 is coupled to a first end of the fourth resistor R4 and a first end of the fifth capacitor C5, a second end of the fifth capacitor C5 is coupled to ground, and a second end of the fourth resistor R4 and a second end of the fourth capacitor C4 are coupled to a second end of the first band-stop filter element 162D.

[0031] like Figure 8C As shown, compared with Figure 8BThe fourth resistor R4 and the fourth capacitor C4 are replaced by a second operational amplifier OP2, a third operational amplifier OP3 and a fourth operational amplifier OP4, wherein the negative input terminals of the second operational amplifier OP2 and the third operational amplifier OP3 are both coupled to the output terminals of the second operational amplifier OP2 and the third operational amplifier OP3, and the positive input terminals of the second operational amplifier OP2 and the third operational amplifier OP3 are respectively coupled to the second terminal of the third resistor R3 and the second terminal of the third capacitor C3, and are respectively coupled to the first terminal of the fifth capacitor C5 and the first terminal of the fifth resistor R5, and ...5, and the second operational amplifier OP2 and the third operational amplifier OP3 are respectively coupled to the second terminal of the third resistor R3 and the second terminal of the third capacitor C3, and the second operational amplifier OP2 and the third operational amplifier The output terminals of OP2 and the third operational amplifier OP3 are further coupled to a first terminal of a sixth resistor R6 and a first terminal of a seventh resistor R7, respectively, and a second terminal of the sixth resistor R6 and a second terminal of the seventh resistor R7 are coupled to a negative input terminal of the fourth operational amplifier OP4. A positive input terminal of the fourth operational amplifier OP4 is coupled to ground. A first terminal and a second terminal of an eighth resistor R8 are coupled between a negative input terminal and an output terminal of the fourth operational amplifier OP4. The output terminal of the fourth operational amplifier OP4 is further coupled to the second terminal of the first band-stop filter element 162D. The remaining connection relationships are the same as those in FIG. Figure 8B A first schematic diagram of the first band-stop filter element 162D is shown.

[0032] like Fig. 9 , which is a schematic diagram of signal transmission according to the eleventh embodiment of the present invention. Fig. 8A and Fig. 9 The difference is Fig. 8A The embodiment of the first filter element 162 and the second filter element 164 is to use the first band-stop filter element 162D and the second band-pass filter element 164B. Fig. 9 The embodiment of the first filter element 162 and the second filter element 164 is to use the first bandpass filter element 162B and a second high-pass filter element 164C, which is equivalent to Figure 5 The first high-pass filter element 162A and the second band-pass filter element 164B are exchanged in the embodiment, so they are not described in detail.

[0033] like Fig.10 , which is a schematic diagram of signal transmission according to the twelfth embodiment of the present invention. Fig. 9 and Fig.10 The difference is Fig. 9 An embodiment of the second filter element 164 is the second high-pass filter element 164C, Fig.10 The second filter element 164 is a second band-stop filter element 164D, which is equivalent to Fig. 8AThe first band-stop filter element 162D and the second band-pass filter element 164B are exchanged in the embodiment, so they are not described in detail.

[0034] The above-described embodiment discloses that the first end of the first filter element 162 is coupled to the non-sensing end 104, that is, the first filter element 162 is disposed in the internal circuit of the sensing device 10; however, the present invention is not limited thereto. Fig.11 As shown, the present invention further discloses another sensing device 20, wherein a first filter element 162 is an external circuit disposed in the sensing device 20, that is, the sensing device 20 is coupled to the sensing circuit 14 and the first filter element 162, and the first end of the first filter element 162 is directly coupled between the capacitive sensing element 142 of the sensing circuit 14 and the first reference power supply NS, and the capacitive sensing element 142 is further coupled to the sensing end 102 to couple to the analog front-end circuit 12, and the second end of the first filter element 162 is coupled to the non-sensing end 104 of the sensing device 20 to couple to the operational element 166, thereby providing a noise compensation signal CS to the analog front-end circuit 12, as described in detail below.

[0035] See also Fig.11 The first filter element 162 of the present embodiment is an external circuit disposed in the sensing device 20, and the second filter element 164 is still disposed in the internal circuit of the sensing device 20. Therefore, the noise compensation circuit 16 of the present embodiment includes the second filter element 164 and the operation element 166. The first filter element 162 generates the first filter signal FS1 according to the sensing reference signal S1 and inputs the first filter signal FS1 to the operation element 166 from the non-sensing end 104, and the second filter signal FS2 generated by the second filter element 164 according to the analog reference signal S2 is still transmitted to the operation element 166 through the internal circuit of the sensing device 20, so that the operation element 166 generates the noise compensation signal CS to the analog front-end circuit 12 according to the first filter signal FS1 and the second filter signal FS2, so that the analog front-end circuit 12 compensates the sensing signal SS from the sensing circuit 14 according to the noise compensation signal CS, thereby generating an output signal OUT with a relatively slow and smooth waveform.

[0036] like Figures 12 to 19 As shown, it is the fourteenth embodiment to the twenty-first embodiment of the present invention, which is Fig.11 The signal transmission diagram of the sensing device 20 is shown in FIG. Fig.11 To illustrate the signal transmission embodiment of the first filter element 162 and the second filter element 164, it is equivalent to Figure 2The signal transmission embodiment of the first filter element 162 and the second filter element 164 changes the setting position of the first filter element 162 to the external circuit of the sensing device 10, and Figure 3A , Figure 4A , Figure 5 , Figure 6 , Figure 7 , Fig. 8A , Figures 9 and 10 An embodiment similar to Figures 12 to 19 , the difference lies in the different setting position of the first filter element 162, so it is not repeated here. Similarly, the sensing device 20 can also generate the corresponding noise compensation signal CS through the first filter element 162, the second filter element 164 and the operating element 166, thereby compensating the first noise N1 of the sensing signal SS received by the analog front-end circuit 12, maintaining the operating voltage characteristics of the analog front-end circuit 12, and improving the signal-to-noise ratio of the sensing circuit 14.

[0037] In summary, the present invention is a sensing device, which includes an analog front-end circuit, a sensing circuit and a noise compensation circuit, wherein the noise compensation circuit includes a first filter element, a second filter element and an operation element, the first filter element is coupled between the sensing circuit and a corresponding sensing reference signal, the second filter element is coupled to an analog reference signal corresponding to the analog front-end circuit, thereby generating a first filter signal and a second filter signal to the operation element respectively, and the operation element generates a noise compensation signal to the analog front-end circuit accordingly, so that the analog front-end circuit compensates the sensing signal transmitted from the sensing circuit to the analog front-end circuit according to the noise compensation signal, thereby reducing a noise of the sensing signal, thereby making the signal waveform of the output signal of the analog front-end circuit slower and smoother, and maintaining the operating voltage characteristics of the analog front-end circuit, and improving the signal-to-noise ratio of the sensing circuit.

[0038] The order of execution of each step in the above embodiment does not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0039] 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 sensing device, characterized in that: It contains: A sensing circuit generates a sensing signal; an analog front-end circuit coupled to the sensing circuit and receiving the sensing signal; and A noise compensation circuit is coupled to the sensing circuit and the analog front-end circuit. The noise compensation circuit includes a first filter element, a second filter element and an operation element. The first filter element generates a first filter signal according to a sensing reference signal corresponding to the sensing signal. The second filter element generates a second filter signal according to an analog reference signal. The operation unit generates a noise compensation signal according to the first filter signal and the second filter signal. The analog front-end circuit compensates the sensing signal according to the noise compensation signal.

2. The sensing device according to claim 1, characterized in that in, The first filter element and the second filter element have different cutoff frequencies.

3. The sensing device according to claim 1, characterized in that in, A first end of the first filter element is coupled between the sensing circuit and a first reference power source, and the first reference power source supplies the sensing reference signal to the sensing circuit. A second end of the first filter element is coupled to the operational element. A first end of the second filter element is coupled to a second reference voltage source, and the second reference voltage source supplies the analog reference signal to the noise compensation circuit. A second end of the second filter element is coupled to the operational element, and the operational element is further coupled to the analog front-end circuit.

4. The sensing device according to claim 3, characterized in that It further comprises a sensing end and a non-sensing end, the sensing circuit is coupled to the analog front-end circuit via the sensing end, and the first end of the first filter element is coupled between the sensing circuit and the sensing reference signal via the non-sensing end.

5. The sensing device according to claim 1, wherein: The analog reference signal corresponds to an operating voltage of the analog front-end circuit.

6. The sensing device according to claim 1, wherein: The first filter element is a first high-pass filter and the second filter element is a second low-pass filter, and a first cut-off frequency of the first filter element is greater than a second cut-off frequency of the second filter element.

7. The sensing device according to claim 1, characterized in that: The first filter element is a first low-pass filter and the second filter element is a second high-pass filter, and a first cut-off frequency of the first filter element is less than a second cut-off frequency of the second filter element.

8. The sensing device according to claim 1, wherein: The first filter element and the second filter element are bandpass filters, and a first cutoff frequency and a second cutoff frequency of the first filter element are greater than or less than a third cutoff frequency and a fourth cutoff frequency of the second filter element.

9. The sensing device according to claim 1, wherein: The first filter element is a first band-pass filter, the second filter element is a second low-pass filter, and a first cut-off frequency and a second cut-off frequency of the first filter element are greater than a third cut-off frequency of the second filter element.

10. The sensing device according to claim 1, wherein: The first filter element is a first bandpass filter, the second filter element is a second high-pass filter, and a first cutoff frequency and a second cutoff frequency of the first filter element are smaller than a third cutoff frequency of the second filter element.

11. The sensing device according to claim 1, characterized in that: The first filter element is a first band-stop filter, and the second filter element is a second band-pass filter. A first cut-off frequency of the first filter element is less than a third cut-off frequency of the second filter element, and a second cut-off frequency of the first filter element is greater than a fourth cut-off frequency of the second filter element.

12. The sensing device according to claim 1, wherein: The first filter element is a first bandpass filter, and the second filter element is a second bandstop filter, a first cutoff frequency of the first filter element is greater than a third cutoff frequency of the second filter element, and a second cutoff frequency of the first filter element is less than a fourth cutoff frequency of the second filter element.

13. The sensing device according to claim 1, wherein: The analog front-end circuit includes an amplifier circuit. The amplifier circuit receives the sensing signal and the noise compensation signal and compensates the sensing signal according to the noise compensation signal to reduce a noise of the sensing signal.

14. A sensing device, characterized in that: The sensing device is coupled to a sensing circuit and a first filter element. The sensing circuit generates a sensing signal. The first filter element is coupled to the sensing circuit and generates a first filter signal according to a sensing reference signal corresponding to the sensing signal. The sensing device comprises: an analog front-end circuit coupled to the sensing circuit and receiving the sensing signal; a second filtering element, generating a second filtering signal according to an analog reference signal corresponding to the analog front-end circuit; and An operation element is coupled to the first filter element, the second filter element and the analog front-end circuit. The operation unit generates a noise compensation signal according to the first filter signal and the second filter signal. The analog front-end circuit compensates the sensing signal according to the noise compensation signal.

15. The sensing device according to claim 14, characterized in that in, The first filter element and the second filter element have different cutoff frequencies.

16. The sensing device according to claim 14, characterized in that in, A first end of the first filter element is coupled between the sensing circuit and a first reference power source, the first reference power source supplies the sensing reference signal to the sensing circuit, a second end of the first filter element is coupled to the operational element, a first end of the second filter element is coupled to a second reference voltage source, the second reference voltage source supplies the analog reference signal to the second filter element, a second end of the second filter element is coupled to the operational element, and the operational element is further coupled to the analog front-end circuit.

17. The sensing device according to claim 16, characterized in that It further comprises a sensing end and a non-sensing end, the sensing circuit is coupled to the analog front-end circuit via the sensing end, and the second end of the first filtering element is coupled to the operation element via the non-sensing end.

18. The sensing device according to claim 14, characterized in that The analog reference signal corresponds to an operating voltage of the analog front-end circuit.

19. The sensing device according to claim 14, wherein: The first filter element is a first high-pass filter and the second filter element is a second low-pass filter, and a first cut-off frequency of the first filter element is greater than a second cut-off frequency of the second filter element.

20. The sensing device according to claim 14, wherein: The first filter element is a first low-pass filter and the second filter element is a second high-pass filter, and a first cut-off frequency of the first filter element is less than a second cut-off frequency of the second filter element.

21. The sensing device according to claim 14, characterized in that The first filter element and the second filter element are bandpass filters, and a first cutoff frequency and a second cutoff frequency of the first filter element are greater than or less than a third cutoff frequency and a fourth cutoff frequency of the second filter element.

22. The sensing device according to claim 14, wherein: The first filter element is a first band-pass filter, the second filter element is a second low-pass filter, and a first cut-off frequency and a second cut-off frequency of the first filter element are greater than a third cut-off frequency of the second filter element.

23. The sensing device according to claim 14, characterized in that The first filter element is a first bandpass filter, the second filter element is a second high-pass filter, and a first cutoff frequency and a second cutoff frequency of the first filter element are smaller than a third cutoff frequency of the second filter element.

24. The sensing device according to claim 14, characterized in that The first filter element is a first band-stop filter, and the second filter element is a second band-pass filter. A first cut-off frequency of the first filter element is less than a third cut-off frequency of the second filter element, and a second cut-off frequency of the first filter element is greater than a fourth cut-off frequency of the second filter element.

25. The sensing device according to claim 14, wherein: The first filter element is a first bandpass filter, and the second filter element is a second bandstop filter, a first cutoff frequency of the first filter element is greater than a third cutoff frequency of the second filter element, and a second cutoff frequency of the first filter element is less than a fourth cutoff frequency of the second filter element.

26. The sensing device according to claim 14, wherein: The analog front-end circuit includes an amplifier circuit. The amplifier circuit receives the sensing signal and the noise compensation signal and compensates the sensing signal according to the noise compensation signal to reduce a noise of the sensing signal.

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