Touch detection circuit and touch detection method thereof

Abstract

A touch detection circuit and a touch detection method thereof are provided. The touch detection circuit coupled to a touch region of a touch panel includes a touch controller and a detection circuit. The touch controller sequentially performs touch detection on the touch region. The detection circuit transmits a first detection signal to a boundary region of the touch region that is not being touch detected to receive a first feedback signal. The detection circuit transmits a second detection signal to a corresponding center region of the touch region that is not being touch detected to receive a second feedback signal. The touch controller compares the first feedback signal with the second feedback signal to generate a capacitance change between the boundary region and the corresponding center region.

Description

Technical Field

[0001] This invention relates to a touch detection circuit, and more specifically to a touch detection circuit and method for determining whether water has come into contact with the metal frame of a smartwatch. Background Technology

[0002] Traditional smartwatches divide the touch panel into multiple areas and perform touch detection on these areas sequentially to receive touch data in a time-division multiplexing manner. For example, a smartwatch's touch panel may be divided into an upper section and a lower section.

[0003] However, when the metal frame of the smartwatch comes into contact with water, the water, being a perfect conductor, will cause grounding, resulting in touch data similar to that of a finger touch and causing touch detection errors. Summary of the Invention

[0004] This invention provides a touch detection circuit with a touch detection method, which determines whether water has touched the metal frame of a smartwatch.

[0005] Embodiments of the present invention provide a touch detection circuit. The touch detection circuit is coupled to a touch panel having multiple touch areas, and each touch area includes multiple boundary areas. The touch detection circuit includes a first detection circuit and a second detection circuit. The first detection circuit selects one of a first signal and a second signal as a first detection signal and transmits the first detection signal to one of the boundary areas of the undetected touch area to receive a first feedback signal. The second detection circuit selects the other of the first signal and the second signal as a second detection signal and transmits the second detection signal to a corresponding central area of ​​the undetected touch area to receive a second feedback signal. The corresponding central area includes all undetected touch areas except for the one of the boundary areas.

[0006] Embodiments of the present invention provide a touch detection method applicable to a touch detection circuit coupled to a touch panel having multiple touch areas, wherein the touch areas include multiple boundary areas. The touch detection circuit includes a first detection circuit and a second detection circuit. The touch detection method includes: the first detection circuit selecting one of a first signal and a second signal as a first detection signal; the first detection circuit transmitting the first detection signal to one of the boundary areas of the undetected touch area to receive a first feedback signal; the second detection circuit selecting the other of the first signal and the second signal as a second detection signal; and the second detection circuit transmitting the second detection signal to a corresponding central area of ​​the undetected touch area to receive a second feedback signal. The corresponding central area includes the undetected touch areas other than the one of the boundary areas.

[0007] Another embodiment of the present invention provides a touch detection circuit. The touch detection circuit is coupled to a touch panel having multiple touch areas, wherein each touch area includes multiple boundary areas. The touch detection circuit includes multiple first detection circuits, multiple second detection circuits, and a third detection circuit. Each of the first detection circuits selects one of a first signal and a second signal as one of a plurality of first detection signals and transmits the first detection signal to one of the boundary areas of the undetected touch area to receive one of a plurality of first feedback signals. Each of the second detection circuits selects another of the first signal and the second signal as one of a plurality of second detection signals and transmits the second detection signal to a corresponding central area of ​​the undetected touch area to receive one of a plurality of second feedback signals. The corresponding central area includes the undetected touch area other than the one in the boundary area. The third detection circuit is coupled to the first detection circuit and the second detection circuits. The first detection circuit and the second detection circuit receive the first signal from the third detection circuit.

[0008] Another embodiment of the present invention provides a touch detection method applicable to a touch detection circuit coupled to a touch panel having multiple touch areas. The touch detection circuit includes multiple first detection circuits, multiple second detection circuits, and a third detection circuit, and the touch areas include multiple boundary areas. The touch detection method includes: each of the first detection circuits selecting one of a first signal and a second signal as one of a plurality of first detection signals; each of the first detection circuits transmitting the first detection signal to one of the boundary areas of the undetected touch area to receive one of a plurality of first feedback signals; each of the second detection circuits selecting the other of the first signal and the second signal as one of a plurality of second detection signals; and each of the second detection circuits transmitting the second detection signal to a corresponding central area of ​​the undetected touch area to receive one of a plurality of second feedback signals. The corresponding central area includes the undetected touch areas other than the boundary areas. The first signal is received from the third detection circuit.

[0009] Based on the above, in an embodiment of the present invention, to address touch detection errors caused by water contacting the metal frame of a smartwatch, an embodiment of the present invention provides a touch detection circuit with a touch detection method. The touch detection method detects water based on the capacitance change between the boundary area and the corresponding center area of ​​the touch panel, thereby improving the reliability of touch detection of the smartwatch without affecting the normal touch detection of the user's finger.

[0010] To make the above features and advantages of the present invention easier to understand, the embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0011] This document includes accompanying drawings to provide a further understanding of the invention, and these drawings are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0012] Figure 1 This is a schematic diagram illustrating a touch detection circuit according to an embodiment of the present invention.

[0013] Figure 2A This is a circuit block diagram illustrating a touch detection circuit according to an embodiment of the present invention.

[0014] Figure 2B This is a circuit block diagram illustrating a touch detection circuit according to an embodiment of the present invention.

[0015] Figure 3A This is a schematic diagram illustrating a touch panel according to an embodiment of the present invention.

[0016] Figure 3B This is a schematic diagram illustrating the detection mechanism according to an embodiment of the present invention.

[0017] Figure 4 This is a schematic diagram illustrating a touch detection circuit according to another embodiment of the present invention.

[0018] Figure 5A This is a circuit block diagram illustrating a touch detection circuit according to another embodiment of the present invention.

[0019] Figure 5B This is a circuit block diagram illustrating a touch detection circuit according to another embodiment of the present invention.

[0020] Figure 6 This is a schematic diagram illustrating a detection mechanism according to another embodiment of the present invention.

[0021] Figure 7 This is a flowchart illustrating a touch detection method according to an embodiment of the present invention.

[0022] Figure 8 This is a flowchart illustrating a touch detection method according to another embodiment of the present invention.

[0023] Figure 9 This is a schematic diagram illustrating a touch detection circuit according to another embodiment of the present invention.

[0024] Figure 10 This is a circuit block diagram illustrating a touch detection circuit according to another embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures:

[0026] 10, 20, 30: Touch detection circuit

[0027] 110, 410_1, 410_2, 410_3, 810: First detection circuit

[0028] 111, 411_1, 411_2, 411_3, 811: First multiplexer

[0029] 112, 412_1, 412_2, 412_3, 812: First operational amplifier

[0030] 113, 422_1, 422_2, 422_3: Second operational amplifier

[0031] 120, 420_1, 420_2, 420_3: Second detection circuit

[0032] 121, 421_1, 421_2, 421_3: Second multiplexer

[0033] 122, 452: Third operational amplifier

[0034] 123: Fourth Operational Amplifier

[0035] 130, 430, 820: Touch controller

[0036] 131, 132, 133, 134, 821: Analog-to-Digital Converters

[0037] 135, 136, 137, 138, 823: Digital back-end circuits

[0038] 139, 439, 825: Processors

[0039] 140, 340, 440_1, 440_2, 440_3, 850: Touch panel

[0040] 431_1, 431_2, 431_3, 432_1, 432_2, 432_3: First Analog-to-Digital Converters

[0041] 435_1, 435_2, 435_3, 436_1, 436_2, 436_3: First digital back-end circuit

[0042] 437: Second Analog-to-Digital Converter

[0043] 438: Second Digital Back-End Circuit

[0044] 450: Third detection circuit

[0045] 451: Third Multiplexer

[0046] 830: Buffer

[0047] 840: Metal frame

[0048] CD1, CD2, CD3, CD4: Capacitors / Equivalent Capacitors

[0049] CD5, CS1, CS2, CS3, CS4, CS5, CS6, CS7, CS8, CS9: Equivalent Capacitors

[0050] D1, D3, D5, D7: First digital signal

[0051] D2, D4, D6, D8: Second digital signal

[0052] DC1, DC3, DC5, DC7: First capacitor data

[0053] DC2, DC4, DC6, DC8: Second capacitor data

[0054] DS1, DS3, DS5, DS7: First detection signal

[0055] DS2, DS4, DS6, DS8: Second detection signals

[0056] DST1, DST2, DST3, DST4, DST5, DST6, DST7, DST8, DST9: Touch digital signals

[0057] FB1, FB3, FB5, FB7: First feedback signals

[0058] FB2, FB4, FB6, FB8: Second feedback signals

[0059] FBT1, FBT1_1, FBT1_2, FBT1_3, FBT2, FBT2_1, FBT2_2, FBT2_3, FBT3: Feedback signals

[0060] LFD: No-load drive signal

[0061] ND: DC voltage signal

[0062] P1, P2, P3, P4, P5, P6, P7, P8, P9: Nodes

[0063] RS1, RS2, RS3, RS4, RS5, RS6, RS7, RS8, RS9: Equivalent Resistor

[0064] S1: First signal / First detection signal

[0065] S2: Second signal / Second detection signal

[0066] S310, S320, S330, S340, S350, S360, S370, S380, S610, S620, S710, S720, S730, S740, S810, S820, S830, S840: Steps

[0067] SP: Sensing pad

[0068] TD1, TD2, TD3, TD4, TD5, TD6, TD7, TD8, TD9: Touch data

[0069] TP1, TP2, TP3, TP4, TP6, TP7, TP10, TP11, TP12, TP13, TP15, TP16, TP19, TP20, TP22, TP23, TP24, TP25, TP28, TP29, TP31, TP32, TP33, TP34: Sensing pads

[0070] TX: Touch detection signal

[0071] TX_AUX: Inverted touch detection signal Detailed Implementation

[0072] The present invention will now be described in detail with reference to embodiments thereof, examples of which are illustrated in the accompanying drawings. The same reference numerals are used as far as possible in the drawings and description to refer to the same or similar parts.

[0073] Reference Figure 1 and Figure 2A The touch detection circuit 10 includes a first detection circuit 110, a second detection circuit 120, and a touch controller 130. The touch detection circuit 10 is coupled to a touch panel having multiple touch areas (e.g., see reference 130). Figure 3A A touch panel 340 (layout configuration) with a touch area is provided and coupled to a metal frame (not shown). The metal frame surrounds the touch panel 340 of the smartwatch (not shown). A first detection circuit 110 is coupled to a touch controller 130, and a second detection circuit 120 is coupled to the touch controller 130.

[0074] The touch controller 130 can sequentially perform touch detection on the touch area using the touch detection signal TX. For example, please refer to... Figure 3A and Figure 3B The sensing pads TP2 to TP33 are divided into an upper portion comprising sensing pads TP1 to TP4, TP6 to TP7, TP19 to TP20, and TP22 to TP25, and a lower portion comprising sensing pads TP10 to TP13, TP15 to TP16, TP28 to TP29, and TP31 to TP34. The touch detection is performed in the following sequence: in steps S310, S330, S350, and S370, touch detection (sensing) is performed on the upper portion and a no-load drive signal LFD is applied to the lower portion; and in steps S320, S340, S360, and S380, touch detection (sensing) is performed on the lower portion and a no-load drive signal LFD is applied to the upper portion. The touch detection signal TX is a time-variant signal, but is not limited thereto. Further details will be explained later. In another embodiment, more detection circuits will not need to sequentially select the touch areas used for normal touch detection.

[0075] The touch controller 130 can sequentially select boundary regions from multiple boundary regions of a touch area that has not been touched. For example, since sensing pads TP15 and TP33 belong to the boundary region of the lower portion that has not been touched in step S330, the touch controller 130 selects sensing pads TP15 and TP33 in step S330. It should be noted that the steps of selecting sensing pads TP15 and TP33 will be implemented by two touch detection circuits 10 according to design requirements, and the subsequent transmission and comparison steps are similar but not limited. In the same manner, the touch controller 130 selects sensing pads TP2 and TP20 in step S340, sensing pads TP12 and TP31 in step S350, sensing pads TP4 and TP23 in step S360, sensing pads TP11 and TP29 in step S370, and sensing pads TP6 and TP24 in step S380. In another embodiment, more detection circuits will not need to sequentially select boundary regions for water detection.

[0076] Next, the first detection circuit 110 selects one of the first signal S1 and the second signal S2 as the first detection signal DS1 and transmits the first detection signal DS1 to the selected boundary area of ​​the touch area that has not been touched to receive the first feedback signal FB1. For example, the first detection circuit 110 selects the first signal S1 as the first detection signal DS1 and transmits the first detection signal DS1 to the selected sensing pads TP15 and TP33 in step S330 and receives the first feedback signal FB1 from the selected sensing pads TP15 and TP33. In step S340, the first detection signal DS1 is transmitted to the sensing pads TP2 and TP20. In step S350, the first detection signal DS1 is transmitted to the sensing pads TP12 and TP31. In step S360, the first detection signal DS1 is transmitted to the sensing pads TP4 and TP23. In step S370, the first detection signal DS1 is transmitted to the sensing pads TP11 and TP29. In step S380, the first detection signal DS1 is transmitted to the sensing pads TP6 and TP24, and the corresponding first feedback signal FB1 is received in steps S340 to S380 respectively.

[0077] The second detection circuit 120 selects the other of the first signal S1 and the second signal S2 as the second detection signal DS2 and transmits the second detection signal DS2 to the corresponding center region of the touch area that has not been touched and receives the second feedback signal FB2. The corresponding center region includes the touch area that has not been touched and is not touched, except for the one in the boundary region. For example, the second detection circuit 120 selects the second signal S2 as the second detection signal DS2 and transmits the second detection signal S2 to the sensing pads TP10, TP11, TP12, TP13, TP16, TP28, TP29, TP31, TP32 and TP34 in step S330 (since these sensing pads belong to the corresponding center region of the lower part that has not been touched and is not touched and is not touched and is in step S330) and receives the second feedback signal FB2 from the sensing pads TP10, TP13, TP16, TP28, TP32 and TP34. In step S340, the second detection circuit 120 transmits the second detection signal S2 to the sensing pads TP1, TP3, TP4, TP6, TP7, TP19, TP22, TP23, TP24, and TP25, and receives the corresponding second feedback signal FB2. Steps S350 to S380 are similar and will not be repeated.

[0078] The touch controller 130 compares the first feedback signal FB1 with the second feedback signal FB2 to generate a capacitance change between the selected boundary region and the corresponding center region. In step S330, the touch controller 130 receives the first feedback signal FB1 and the second feedback signal FB2 from the first detection circuit 110 and the second detection circuit 120, and compares the first feedback signal FB1 with the second feedback signal FB2 (the first feedback signal FB1 and the second feedback signal FB2 together include capacitance change information between the selected boundary region (TP15 and TP33) and the corresponding center region (TP10, TP11, TP12, TP13, TP16, TP28, TP29, TP31, TP32, and TP34)) to generate a capacitance change between the selected boundary region and the corresponding center region in step S330. Further details will be described thereafter, and the comparison operations in steps S340 to S380 will not be repeated.

[0079] Reference Figure 2A The first detection circuit 110 includes a first multiplexer 111, a first operational amplifier 112, and a second operational amplifier 113. The first multiplexer 111 is coupled to the touch panel 140 (equivalent circuit) and selects one of the touch detection signal TX, the first signal S1, and the second signal S2 according to the control signal (not shown) from the touch controller 130, and transmits the selected signal to node P1 of the touch panel 140.

[0080] The first input terminal of the first operational amplifier 112 is coupled to the first multiplexer 111, the second input terminal of the first operational amplifier 112 receives the touch detection signal TX, and the output terminal of the first operational amplifier 112 is coupled to the first input terminal of the first operational amplifier 112.

[0081] The first input terminal of the second operational amplifier 113 is coupled to the first multiplexer 111, the second input terminal of the second operational amplifier 113 receives the first signal S1, and the output terminal of the second operational amplifier 113 is coupled to the first input terminal of the second operational amplifier 113.

[0082] Additionally, the first multiplexer 111 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT1 of the touch detection signal TX, and transmits the first detection signal DS1 to a selected boundary area of ​​the touch area not being touched to receive the first feedback signal FB1. Taking step S330 as an example, the first multiplexer 111 transmits the touch detection signal TX to the upper portion of the touch panel 340 to receive the feedback signal FBT1 from the upper portion of the touch panel 340, and transmits the first detection signal DS1 to the sensing pads TP15 and TP33 to receive the first feedback signal FB1 from the sensing pads TP15 and TP33.

[0083] Reference Figure 2A The second detection circuit 120 includes a second multiplexer 121, a third operational amplifier 122, and a fourth operational amplifier 123. The second multiplexer 121 is coupled to the touch panel 140 (equivalent circuit), and the second multiplexer 121 selects one of the touch detection signal TX, the first signal S1, and the second signal S2 according to the control signal (not shown) from the touch controller 130, and transmits the selected one to node P2 of the touch panel 140.

[0084] The first input terminal of the third operational amplifier 122 is coupled to the second multiplexer 121, the second input terminal of the third operational amplifier 122 receives the touch detection signal TX, and the output terminal of the third operational amplifier 122 is coupled to the first input terminal of the third operational amplifier 122.

[0085] The first input terminal of the fourth operational amplifier 123 is coupled to the second multiplexer 121, the second input terminal of the fourth operational amplifier 123 receives the first signal S1, and the output terminal of the fourth operational amplifier 123 is coupled to the first input terminal of the fourth operational amplifier 123.

[0086] Additionally, the second multiplexer 121 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT2 of the touch detection signal TX, and transmits the second detection signal DS2 to the corresponding center area not being touched to receive the second feedback signal FB2. Taking step S330 as an example, the second multiplexer 121 transmits the touch detection signal TX to the upper portion of the touch panel 340 to receive the feedback signal FBT2 from the upper portion of the touch panel 340, and transmits the second detection signal DS2 to the corresponding center areas (TP10, TP11, TP12, TP13, TP16, TP28, TP29, TP31, TP32, and TP34) of the lower portion to receive the second feedback signal FB2 from the corresponding center areas (TP10, TP11, TP12, TP13, TP16, TP28, TP29, TP31, TP32, and TP34).

[0087] Reference Figure 2A The touch controller 130 includes analog-to-digital converters 131 to 134, digital back-end circuits 135 to 138, and a processor 139. Analog-to-digital converters 131 and 132 are coupled to a first detection circuit 110, and analog-to-digital converters 133 and 134 are coupled to a second detection circuit 120. Analog-to-digital converters 132 and 134 convert a first feedback signal FB1 and a second feedback signal FB2 into a first digital signal D1 and a second digital signal D2, respectively. Analog-to-digital converters 131 and 133 convert the feedback signals FBT1 and FBT2 of the touch detection signal TX into touch digital signals DST1 and DST2.

[0088] Digital back-end circuits 135 and 136 are coupled to analog-to-digital converters 131 and 132, respectively, and digital back-end circuits 137 and 138 are coupled to analog-to-digital converters 133 and 134, respectively. Digital back-end circuits 136 and 138 perform digital signal processing on the first digital signal D1 and the second digital signal D2, respectively, to generate first capacitance data DC1 and second capacitance data DC2. Digital back-end circuits 135 and 137 perform digital signal processing on the touch digital signals DST1 and DST2, respectively, to generate touch data TD1 and TD2. It should be noted that digital signal processing includes digital filtering to reduce noise, but this is not limited to this invention.

[0089] Processor 139 is coupled to digital back-end circuits 135 to 138, and processor 139 calculates the difference between first capacitance data DC1 and second capacitance data DC2 to generate a capacitance change between a selected boundary region and a corresponding center region. The processor also receives touch data TD1 and TD2 to perform normal touch calculations.

[0090] The touch panel 140 (equivalent circuit) includes equivalent resistors RS1 and RS2 and equivalent capacitors CD1, CS1, and CS2. It should be noted that the equivalent resistors RS1 and RS2 and the equivalent capacitors CD1, CS1, and CS2 are only equivalent devices and not actual devices. The equivalent capacitor CD1 between nodes P1 and P2 represents the equivalent capacitor between the boundary region and the corresponding center region of the touch panel 340. Furthermore, the first capacitance data DC1 and the second capacitance data DC2 correspond to the voltages at nodes P1 and P2, respectively.

[0091] It is worth noting that, to generate the capacitance change of capacitor CD1, the first detection signal DS1 and the second detection signal DS2 should be different, and due to the measurable voltage change between nodes P1 and P2, at least one of the first detection signal DS1 and the second detection signal DS2 should be a time-varying signal. In some embodiments shown in Type 1 of Table 1, the first detection signal DS1 is a direct current (DC) voltage signal ND, and the second detection signal DS2 is a no-load drive signal LFD that is in phase with the touch detection signal TX, wherein the touch detection signal can be a time-varying signal used for touch detection, such as a square wave. In other embodiments shown in Type 2 of Table 1, the first detection signal DS1 is the touch detection signal TX, and the second detection signal DS2 is an inverted touch detection signal TX_AUX.

[0092] Table 1

[0093]

[0094] Reference Figure 2A , Figure 3A and Figure 3B Based on all capacitance changes between nodes P1 (representing the boundary region) and P2 (representing the corresponding center region) generated sequentially in steps S330 to S380, processor 139 determines whether water has touched the metal frame of the smartwatch. Specifically, processor 139 determines whether the boundary region of the touch panel 340 is coupled to the metal frame of the smartwatch through water based on the value of the capacitance change. This can be implemented by determining whether the sign of the calculated capacitance change is a positive value greater than a threshold, since capacitance changes caused by water are positive but capacitance changes caused by the user's finger are negative, but this is not a limitation.

[0095] Reference Figure 2B ,and Figure 2A In contrast, there is no path for normal touch detection. In this embodiment, the touch detection circuit 10 performs a determination of whether water has touched the metal frame of the smartwatch without performing normal touch detection. Figure 2B Other details of the operation will be referred to Figure 2AThe aforementioned explanation.

[0096] Reference Figure 4 and Figure 5A The touch detection circuit 20 includes first detection circuits 410_1 to 410_3, second detection circuits 420_1 to 420_3, a touch controller 430, and a third detection circuit 450. The touch detection circuit 20 is coupled to a touch panel having multiple touch areas (e.g., see reference 450). Figure 3A A touch panel 340 (layout configuration) with a touch area is provided, and the touch panel 340 is coupled to a metal frame (not shown). The metal frame surrounds the touch panel 340 of the smartwatch (not shown). First detection circuits 410_1 to 410_3 are coupled to a touch controller 430, second detection circuits 420_1 to 420_3 are coupled to the touch controller 430, and a third detection circuit 450 is coupled to the first detection circuits 410_1 to 410_3, the second detection circuits 420_1 to 420_3, and the touch controller 430.

[0097] The touch controller 430 can sequentially perform touch detection on the touch area using the touch detection signal TX. For example, please refer to... Figure 3A and Figure 3B The sensing pads TP2 to TP33 are divided into an upper portion comprising sensing pads TP1 to TP4, TP6 to TP7, TP19 to TP20, and TP22 to TP25, and a lower portion comprising sensing pads TP10 to TP13, TP15 to TP16, TP28 to TP29, and TP31 to TP34. The touch detection is performed in the following order: In step S610, touch detection (sensing) is performed on the upper portion, and a no-load drive signal LFD is applied to the corresponding central area of ​​the lower portion; in step S620, touch detection (sensing) is performed on the lower portion, and a no-load drive signal LFD is applied to the corresponding central area of ​​the upper portion. The touch detection signal TX is a time-varying signal, but is not limited to any particular type. Further details will be described later. In another embodiment, more detection circuitry will not need to sequentially select the touch areas for normal touch detection.

[0098] Next, the first detection circuits 410_1 to 410_3 receive the first signal S1 from the third detection circuit 450, select one of the first signal S1 and the second signal S2 as the first detection signal DS3, DS5, DS7, and transmit the first detection signal DS3, DS5, DS7 to the boundary area of ​​the touch area that has not been touched to receive the first feedback signal FB3, FB5, FB7. Specifically, in step S610, the first detection circuits 410_1 to 410_3 respectively transmit the first detection signals DS3, DS5, and DS7 to the sensing pads TP11, TP12, TP15, TP29, TP31, and TP33 and receive the first feedback signals FB3, FB5, and FB7 from the sensing pads TP11, TP12, TP15, TP29, TP31, and TP33. In step S620, the first detection signals DS3, DS5, and DS7 are transmitted to the sensing pads TP2, TP4, TP6, TP20, TP23, and TP24 and the first feedback signals FB3, FB5, and FB7 are received from the sensing pads TP2, TP4, TP6, TP20, TP23, and TP24.

[0099] The second detection circuits 420_1 to 420_3 receive the first signal S1 from the third detection circuit 450, select one of the first signal S1 and the second signal S2 as the second detection signal, and transmit the second detection signals DS4, DS6, and DS8 to the corresponding central area of ​​the touch area that has not been touched in the detection process to receive the second feedback signals FB4, FB6, and FB8. Specifically, in step S610, the second detection circuits 420_1 to 420_3 transmit the second detection signals DS4, DS6, and DS8 to the sensing pads TP10, TP13, TP16, TP28, TP32, and TP34 (since these sensing pads belong to the corresponding central area of ​​the lower part that has not been touched in the detection process in step S610) and receive the second feedback signals FB4, FB6, and FB8 from the sensing pads TP10, TP13, TP16, TP28, TP32, and TP34. Similarly, in step S620, the second detection circuits 420_1 to 420_3 transmit the second detection signals DS4, DS6, and DS8 to the sensing pads TP1, TP3, TP7, TP19, TP22, and TP25, and receive the second feedback signals FB4, FB6, and FB8 from the sensing pads TP1, TP3, TP7, TP19, TP22, and TP25.

[0100] The touch controller 430 compares the first feedback signals FB3, FB5 and FB7 with the second feedback signals FB4, FB6 and FB8 to generate the total capacitance change between the boundary region and the corresponding center region. In step S610, the touch controller 430 receives first feedback signals FB3, FB5, and FB7 and second feedback signals FB4, FB6, and FB8 from the first detection circuits 410_1 to 410_3 and the second detection circuits 420_1 to 420_3. In step S610, the first feedback signals FB3, FB5, and FB7 are compared with the second feedback signals FB4, FB6, and FB8 (the first feedback signals FB3, FB5, and FB7 and the second feedback signals FB4, FB6, and FB8 together include capacitance change information between the boundary regions (TP11, TP12, TP15, TP29, TP31, TP33) and the corresponding center regions (TP10, TP13, TP16, TP28, TP32, and TP34). The total capacitance change between the boundary regions and the corresponding center regions is generated through the accumulation operation in step S610. Further details will be described later, and the comparison operation in step S620 will not be repeated.

[0101] Reference Figure 5A The first detection circuit 410_1 includes a first multiplexer 411_1 and a first operational amplifier 412_1; the first detection circuit 410_2 includes a first multiplexer 411_2 and a first operational amplifier 412_2; and the first detection circuit 410_3 includes a first multiplexer 411_3 and a first operational amplifier 412_3. The first multiplexer 411_1 is coupled to the touch panel 440_1 (equivalent circuit), selects one of a touch detection signal TX, a first signal S1, and a second signal S2 according to a control signal (not shown) from the touch controller 430, and transmits the selected signal to node P3 of the touch panel 440_1. The first multiplexers 411_2 and 411_3 are similar and will not be repeated.

[0102] The first input terminal of the first operational amplifier 412_1 is coupled to the first multiplexer 411_1, the second input terminal of the first operational amplifier 412_1 receives the touch detection signal TX, and the output terminal of the first operational amplifier 412_1 is coupled to the first input terminal of the first operational amplifier 412_1. The first operational amplifiers 412_2 and 412_3 are similar and will not be repeated.

[0103] Additionally, the first multiplexer 411_1 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT1_1 of the touch detection signal TX, and transmits the first detection signal DS1 to the corresponding boundary area of ​​the touch area not being touched to receive the first feedback signal FB3. Taking step S610 as an example, the first multiplexer 411_1 transmits the touch detection signal TX to the upper portion of the touch panel 340 to receive the feedback signal FBT1_1 from the upper portion of the touch panel 340, and transmits the first detection signal DS3 to the sensing pads TP15 and TP33 to receive the first feedback signal FB3 from the sensing pads TP15 and TP33. Similarly, the first multiplexer 411_2 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT1_2 of the touch detection signal TX, and transmits the first detection signal DS5 to the sensing pads TP12 and TP31 of the touch area not being touched to receive the first feedback signal FB5. The first multiplexer 411_3 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT1_3 of the touch detection signal TX, and transmits the first detection signal DS7 to the sensing pads TP11 and TP29 of the touch area not being touched to receive the first feedback signal FB7.

[0104] Reference Figure 5A The second detection circuit 420_1 includes a second multiplexer 421_1 and a second operational amplifier 422_1; the second detection circuit 420_2 includes a second multiplexer 421_2 and a second operational amplifier 422_2; and the second detection circuit 420_3 includes a second multiplexer 421_3 and a second operational amplifier 422_3. The second multiplexer 421_1 is coupled to the touch panel 440_1 (equivalent circuit), selects one of the touch detection signal TX, the first signal S1, and the second signal S2 according to the control signal (not shown) from the touch controller 430, and transmits the selected signal to node P4 of the touch panel 440_1. The second multiplexers 421_2 and 421_3 are similar and will not be repeated.

[0105] The first input terminal of the second operational amplifier 422_1 is coupled to the second multiplexer 421_1. The second input terminal of the second operational amplifier 422_1 receives the touch detection signal TX, and the output terminal of the second operational amplifier 422_1 is coupled to the first input terminal of the second operational amplifier 422_1. The second operational amplifiers 422_2 and 422_3 are similar and will not be repeated.

[0106] Additionally, the second multiplexer 421_1 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT2_1 of the touch detection signal TX, and transmits the second detection signal DS4 to the corresponding center area of ​​the touch area not being touched to receive the second feedback signal FB4. Taking step S610 as an example, the second multiplexer 421_1 transmits the touch detection signal TX to the upper portion of the touch panel 340 to receive the feedback signal FBT2_1 from the upper portion of the touch panel 340, and transmits the second detection signal DS4 to the sensing pads TP10, TP13, TP16, TP28, TP32, and TP34 to receive the second feedback signal FB4 from the sensing pads TP10, TP13, TP16, TP28, TP32, and TP34. Similarly, the second multiplexer 421_2 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT2_2 of the touch detection signal TX, and transmits the second detection signal DS6 to the sensing pads TP10, TP13, TP16, TP28, TP32 and TP34 of the touch area not being touched to receive the second feedback signal FB6. The second multiplexer 421_3 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT2_3 of the touch detection signal TX, and transmits the second detection signal DS8 to the sensing pads TP10, TP13, TP16, TP28, TP32 and TP34 of the touch area not being touched to receive the second feedback signal FB8.

[0107] Reference Figure 5A The third detection circuit 450 includes a third multiplexer 451 and a third operational amplifier 452. The third multiplexer 451 is coupled to the first detection circuits 410_1 to 410_3 and the second detection circuits 420_1 to 420_3, and receives first feedback signals FB3, FB5, and FB7 and second feedback signals FB4, FB6, and FB8 from the first detection circuits 410_1 to 410_3 and the second detection circuits 420_1 to 420_3. The first input terminal of the third operational amplifier 452 is coupled to the third multiplexer 451, the second input terminal of the third operational amplifier 452 receives the first signal S1, and the output terminal of the third operational amplifier 452 is coupled to the first input terminal of the third operational amplifier 452. The third multiplexer 451 transmits the first detection signal S1 to the first detection circuits 410_1 to 410_3 and receives the first feedback signals FB3, FB5, and FB7 from the first detection circuits 410_1 to 410_3. The third multiplexer 451 also receives the second feedback signals FB4, FB6, and FB8 from the second detection circuits 420_1 to 420_3. It should be noted that the aforementioned operations of the third multiplexer 451 are performed sequentially in a time-division manner.

[0108] Reference Figure 5A The touch controller 430 includes first analog-to-digital converters 431_1 to 431_3 and 432_1 to 432_3, first digital back-end circuits 435_1 to 435_3 and 436_1 to 436_3, a second analog-to-digital converter 437, a second digital back-end circuit 438, and a processor 439. The first analog-to-digital converters 431_1 to 431_3 are respectively coupled to first detection circuits 410_1 to 410_3, and the first analog-to-digital converters 432_1 to 432_3 are respectively coupled to second detection circuits 420_1 to 420_3. The first analog-to-digital converters 431_1 to 431_3 and 432_1 to 432_3 convert the feedback signals FBT1_1 to FBT1_3 and FBT2_1 to FBT2_3 of the touch detection signal TX into touch digital signals DST3 to DST8.

[0109] The first digital back-end circuits 435_1 to 435_3 are coupled to the first analog-to-digital converters 431_1 to 431_3, respectively, and the first digital back-end circuits 436_1 to 436_3 are coupled to the first analog-to-digital converters 432_1 to 432_3, respectively. The first digital back-end circuits 435_1 to 435_3 and 436_1 to 436_3 perform digital signal processing on the touch digital signals DST3 to DST8 to generate touch data TD3 to TD8. It should be noted that digital signal processing includes digital filtering to reduce noise, but this is not limited to this invention.

[0110] The second analog-to-digital converter 437 is coupled to the third detection circuit 450. It receives the first feedback signals FB3, FB5, FB7 and the second feedback signals FB4, FB6, FB8 from the third operational amplifier 452 of the third detection circuit 450 and converts the first feedback signals FB3, FB5, FB7 and the second feedback signals FB4, FB6, FB8 into the first digital signals D3, D5, D7 and the second digital signals D4, D6, D8 in sequence.

[0111] The second digital back-end circuit 438 is coupled to the second analog-to-digital converter 437, and the second digital back-end circuit 438 receives the first digital signals D3, D5, D7 and the second digital signals D4, D6, D8 and performs digital signal processing on the first digital signals D3, D5, D7 and the second digital signals D4, D6, D8 to generate the first capacitor data DC3, DC5, DC7 and the second capacitor data DC4, DC6, DC8.

[0112] Processor 439 is coupled to the second digital back-end circuit 438, and processor 439 calculates the difference between the sum of the first capacitance data DC3, DC5, and DC7 and the sum of the second capacitance data DC4, DC6, and DC8 to generate the total capacitance change between the boundary region and the corresponding central region. Figure 5A In this embodiment, the processor also receives touch data TD3 to TD8 to perform normal touch calculations.

[0113] The touch panels 440_1, 440_2, and 440_3 (equivalent circuits) include equivalent resistors RS3 to RS8 and equivalent capacitors CD2 to CD4 and CS3 to CS8. It should be noted that the equivalent resistors RS3 to RS8 and equivalent capacitors CD2 to CD4 and CS3 to CS8 are only equivalent components, not actual components. The equivalent capacitor CD2 between nodes P3 and P4, the equivalent capacitor CD3 between nodes P5 and P6, and the equivalent capacitor CD4 between nodes P7 and P8 collectively represent... Figure 6 The equivalent capacitor between the boundary area and the corresponding center area of ​​the touch panel 340. In addition, the first capacitance data DC3, DC5, DC7 and the second capacitance data DC4, DC6, DC8 correspond to the voltages of nodes P3, P5, P7 and the voltages of nodes P4, P6, P8, respectively.

[0114] It is worth noting that, in order to generate capacitance changes in capacitors CD2, CD3, and CD4, the first detection signals DS3, DS5, and DS7 should be different from the second detection signals DS4, DS6, and DS8. Furthermore, due to the measurable voltage changes between nodes P3, P5, and P7 and nodes P4, P6, and P8, either the first detection signal DS3, DS5, and DS7 or the second detection signal DS4, DS6, and DS8 should be time-varying signals. In some embodiments shown in Type 1 of Table 1, the first detection signals DS3, DS5, and DS7 are DC voltage signals ND, and the second detection signals DS4, DS6, and DS8 are no-load drive signals LFD that are in phase with the touch detection signal TX. In other embodiments shown in Type 2 of Table 1, the first detection signal S1 is the touch detection signal TX, and the second detection signal S2 is the inverted touch detection signal TX_AUX.

[0115] Reference Figure 5A and Figure 6Based on all capacitance changes between nodes P3, P5, P7 (representing boundary areas) and nodes P4, P6, P8 (representing corresponding central areas) generated in steps S610 to S620, processor 439 determines whether water has touched the metal frame of the smartwatch. Specifically, processor 439 determines whether the boundary area of ​​the touch panel 340 is coupled to the metal frame of the smartwatch through water based on the value of the capacitance change. This is done by determining whether the sign of the calculated capacitance change is a positive value greater than a threshold, since capacitance changes caused by water are positive but capacitance changes caused by the user's finger are negative. Based on the foregoing, processor 439 determines whether this touch is caused by the user's finger or water on the metal frame.

[0116] Reference Figure 5B ,and Figure 5A In contrast, there is no path for normal touch detection. In this embodiment, the touch detection circuit 20 performs a determination of whether water has touched the metal frame of the smartwatch without performing normal touch detection. Figure 5B Other details of the operation will be referred to Figure 5A The aforementioned explanation.

[0117] Figure 7 A flowchart of a touch detection method according to an embodiment of the present disclosure is shown. The touch detection method is applicable to a touch detection circuit coupled to a touch panel having multiple touch areas. The touch detection circuit includes a first detection circuit and a second detection circuit, and the touch areas include multiple boundary areas. The touch detection method includes the following steps: In step S710, the first detection circuit selects one of a first signal and a second signal as a first detection signal. Next, in step S720, the first detection circuit transmits the first detection signal to one of the boundary areas of the touch area that is not being touched to receive a first feedback signal. In step S730, the second detection circuit selects the other of the first signal and the second signal as a second detection signal and in step S740 transmits the second detection signal to the corresponding center area of ​​the touch area that is not being touched to receive a second feedback signal.

[0118] Figure 8 A flowchart illustrating a touch detection method according to another embodiment of the present disclosure is shown. Figure 8 and Figure 7 Similar, and Figure 8 and Figure 7 The only difference lies in the number of first detection signals and the number of second detection signals. Therefore, steps S810, S820, S830, and S840 will no longer be repeated.

[0119] Reference Figure 9 and Figure 10The touch detection circuit 30 includes a first detection circuit 810, a touch controller 820, a buffer 830, and a metal frame 840. The touch detection circuit 30 is coupled to a touch panel having multiple touch areas (e.g., see reference 840). Figure 3A A touch panel 340 (layout configuration) with a touch area is provided, and the touch panel 340 is coupled to a metal frame 840. The metal frame 840 surrounds the touch panel 340 of the smartwatch (not shown). A first detection circuit 810 and a buffer 830 are coupled to a touch controller 820, and the metal frame 840 is coupled to the buffer 830.

[0120] The touch controller 820 provides a touch detection signal TX and a no-load drive signal LFD to the first detection circuit 810. The first detection circuit 810 alternately sends the touch detection signal TX and the no-load drive signal LFD to the upper and lower portions of the touch panel 340, and the touch detection circuit 30 performs touch detection on the touch areas of the touch panel sequentially using the touch detection signal TX and the no-load drive signal LFD. In this embodiment, the order of touch detection is only performed as steps S310 and S320. In step S310, touch detection (sensing) is performed on the upper portion using the touch detection signal TX, and the no-load drive signal LFD is applied to the lower portion. In step S320, touch detection (sensing) is performed on the lower portion using the touch detection signal TX, and the no-load drive signal LFD is applied to the upper portion. The touch detection signal TX is a time-varying signal, but it is not limited.

[0121] Additionally, a no-load drive signal LFD is applied to the buffer 830, and the buffer 830 provides the buffered no-load drive signal LFD to the metal frame 840 of the smartwatch. The buffered no-load drive signal is then provided to the sensing pad SP of the touch panel 850 (equivalent circuit) through the metal frame 840 of the smartwatch.

[0122] The touch panel 850 (equivalent circuit) includes an equivalent resistor RS9 and equivalent capacitors CD5 and CS9. It should be noted that the equivalent resistor RS9 and equivalent capacitors CD5 and CS9 are only equivalent components, not actual components. The equivalent capacitor CD5 between node P9 and the sensing pad SP represents the equivalent capacitor between the detection position and the metal frame.

[0123] Reference Figure 10 The first detection circuit 810 includes a first multiplexer 811 and a first operational amplifier 812. The first multiplexer 811 is coupled to the touch panel 850 (equivalent circuit) and selects one of the touch detection signal TX and the no-load drive signal LFD according to the control signal (not shown) from the touch controller 820 and transmits the selected one to node P9 of the touch panel 850.

[0124] The first input terminal of the first operational amplifier 812 is coupled to the first multiplexer 811, the second input terminal of the first operational amplifier 812 receives the touch detection signal TX, and the output terminal of the first operational amplifier 812 is coupled to the first input terminal of the first operational amplifier 812.

[0125] Additionally, the first multiplexer 811 transmits the touch detection signal TX to the touch area being touched to receive the feedback signal FBT3 from the touch detection signal TX, and transmits the no-load drive signal LFD to the touch area not being touched. Taking step S310 as an example, the first multiplexer 111 transmits the touch detection signal TX to the upper portion of the touch panel 340 to receive the feedback signal FBT3 from the upper portion of the touch panel 340, and transmits the no-load drive signal LFD to the lower portion of the touch panel 340.

[0126] Reference Figure 10 The touch controller 820 includes an analog-to-digital converter 821, a digital back-end circuit 823, and a processor 825. The analog-to-digital converter 821 is coupled to the first detection circuit 810. The analog-to-digital converter 821 converts the feedback signal FBT3 of the touch detection signal TX into a touch digital signal DST9.

[0127] Digital back-end circuitry 823 is coupled to analog-to-digital converter 821. Digital back-end circuitry 823 performs digital signal processing on the touch digital signal DST9 to generate touch data TD9. It should be noted that digital signal processing includes digital filtering to reduce noise, but is not limited to this.

[0128] The processor 825 is coupled to the digital back-end circuit 823, and the processor 825 receives touch data TD9 to perform normal touch calculations.

[0129] In this embodiment, since a buffered, no-load drive signal LFD, in phase with the touch detection signal TX, is applied to the sensing pad SP, the equivalent capacitor CD5 between node P9 (representing the equivalent capacitor between the detection position and the metal frame) and the sensing pad SP should be ignored. That is, the touch data TD9 is unaffected regardless of whether water comes into contact with the smartwatch's metal frame. This demonstrates the benefit of reducing touch detection errors caused by water and saving computational resources without additional front-end and back-end circuitry.

[0130] Based on the above, in embodiments of the present invention, to address touch detection errors caused by water contacting the metal frame of a smartwatch, embodiments of the present invention provide a touch detection circuit with a touch detection method. This touch detection method detects water based on the capacitance change between the boundary area and the corresponding center area of ​​the touch panel, thereby improving the reliability of touch detection in the smartwatch. Even if water contacts the metal frame of the smartwatch, it does not affect normal touch detection of the user's finger. In another embodiment, by providing a no-load drive signal to the sensing pad of the touch panel via the metal frame, whether water contacts the metal frame can be ignored, thereby improving the reliability of touch detection while saving layout area and computing resources.

[0131] It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope or spirit of the invention. In view of the foregoing, this invention is intended to cover modifications and variations of the invention that fall within the scope of the foregoing claims and their equivalents.

Claims

1. A touch detection circuit coupled to a touch panel having multiple touch areas, wherein the touch areas include multiple boundary areas, the touch detection circuit comprising: A first detection circuit is configured to select one of a first signal and a second signal as a first detection signal and transmit the first detection signal to one of the plurality of boundary regions of the touch area that is not touched and is not detected in the touch area to receive a first feedback signal. as well as The second detection circuit is configured to select the other of the first signal and the second signal as the second detection signal and transmit the second detection signal to the corresponding central region of the undetected touch area to receive a second feedback signal, wherein the corresponding central region includes the undetected touch area other than one of the plurality of boundary regions.

2. The touch detection circuit according to claim 1, wherein the touch detection circuit further includes a touch controller coupled to the first detection circuit and the second detection circuit, wherein the touch controller selects one of the boundary regions of the undetected touch area, and compares the first feedback signal with the second feedback signal to generate a capacitance change between the selected boundary region and the corresponding center region.

3. The touch detection circuit according to claim 2, wherein the touch controller comprises: Multiple analog-to-digital converters are coupled to the first detection circuit and the second detection circuit respectively, and are configured to convert the first feedback signal and the second feedback signal into a first digital signal and a second digital signal, and to convert the feedback signal of the touch detection signal into a touch digital signal. Multiple digital back-end circuits, respectively coupled to the multiple analog-to-digital converters, are configured to perform digital signal processing on the first digital signal and the second digital signal to generate first capacitance data and second capacitance data, and to perform the digital signal processing on the touch digital signal to generate multiple touch data. as well as A processor, coupled to the plurality of digital back-end circuits, is configured to calculate the difference between the first capacitance data and the second capacitance data to generate the capacitance change between the selected boundary region and the corresponding central region.

4. The touch detection circuit according to claim 2, wherein the first detection circuit comprises: A first multiplexer, coupled to the touch panel, is configured to select one of a touch detection signal, the first signal, and the second signal, and transmit the one of the touch detection signal, the first signal, and the second signal to the touch panel; A first operational amplifier, wherein a first input terminal of the first operational amplifier is coupled to the first multiplexer, a second input terminal of the first operational amplifier receives the touch detection signal, and an output terminal of the first operational amplifier is coupled to the first input terminal of the first operational amplifier; as well as A second operational amplifier has its first input terminal coupled to the first multiplexer, its second input terminal receiving the first signal, and its output terminal coupled to the first input terminal. The first multiplexer transmits the touch detection signal to the touch area that is being touched in the touch area to receive a feedback signal of the touch detection signal, and transmits the first detection signal to the selected boundary area of ​​the touch area that is not being touched to receive the first feedback signal.

5. The touch detection circuit according to claim 2, wherein the second detection circuit comprises: A second multiplexer, coupled to the touch panel, is configured to select one of a touch detection signal, the first signal, and the second signal, and transmit the one of the touch detection signal, the first signal, and the second signal to the touch panel; A third operational amplifier, wherein the first input terminal of the third operational amplifier is coupled to the second multiplexer, the second input terminal of the third operational amplifier receives the touch detection signal, and the output terminal of the third operational amplifier is coupled to the first input terminal of the third operational amplifier; as well as A fourth operational amplifier, wherein the first input terminal of the fourth operational amplifier is coupled to the second multiplexer, the second input terminal of the fourth operational amplifier receives the first signal, and the output terminal of the fourth operational amplifier is coupled to the first input terminal of the fourth operational amplifier. The second multiplexer transmits the touch detection signal to the touch area being touched in the touch area to receive the feedback signal of the touch detection signal, and transmits the second detection signal to the corresponding central area to receive the second feedback signal.

6. The touch detection circuit according to claim 1, wherein the first signal is a DC voltage signal, and the second signal is a no-load drive signal in phase with the touch detection signal.

7. The touch detection circuit according to claim 1, wherein the first signal is a touch detection signal and the second signal is an inverted touch detection signal.

8. A touch detection method, applicable to a touch detection circuit coupled to a touch panel having multiple touch areas, wherein the touch detection circuit includes a first detection circuit and a second detection circuit, and the touch areas include multiple boundary areas, the touch detection method comprising: The first detection circuit selects one of the first signal and the second signal as the first detection signal; The first detection circuit transmits the first detection signal to one of the plurality of boundary regions of the touch area that is not touched and is not detected in the touch area to receive the first feedback signal. The second detection circuit selects the other of the first signal and the second signal as the second detection signal; as well as The second detection circuit transmits the second detection signal to the corresponding center area of ​​the undetected touch area to receive the second feedback signal. The corresponding central region includes touch areas that are not detected by touch, except for one of the plurality of boundary regions.

9. The touch detection method according to claim 8, further comprising: Select one of the plurality of boundary regions of the touch area that was not detected by touch; as well as The first feedback signal is compared with the second feedback signal to generate the capacitance change between the selected boundary region and the corresponding center region.

10. The touch detection method according to claim 9, further comprising: The first feedback signal and the second feedback signal are converted into a first digital signal and a second digital signal, respectively. Digital signal processing is performed on the first digital signal and the second digital signal to generate first capacitance data and second capacitance data; as well as The difference between the first capacitance data and the second capacitance data is calculated to generate the capacitance change between the selected boundary region and the corresponding center region.

11. The touch detection method according to claim 9, further comprising: The touch detection signal is transmitted to the touch area that is being touched in the touch area to receive the feedback signal of the touch detection signal; the first detection signal is transmitted to the selected boundary area of ​​the touch area that is not being touched to receive the first feedback signal; and the second detection signal is transmitted to the corresponding center area to receive the second feedback signal.

12. A touch detection circuit coupled to a touch panel having multiple touch areas, wherein the touch areas include multiple boundary areas, the touch detection circuit comprising: A plurality of first detection circuits, each of which is configured to select one of a first signal and a second signal as one of a plurality of first detection signals and transmit the one of the plurality of first detection signals to one of a plurality of boundary regions of the un-touch-detected touch area in the touch area to receive one of a plurality of first feedback signals; A plurality of second detection circuits, each of the second detection circuits being configured to select one of the first signal and the second signal as one of a plurality of second detection signals and transmit the one of the plurality of second detection signals to a corresponding central region of the undetected touch area to receive one of a plurality of second feedback signals, wherein the corresponding central region includes the undetected touch area other than the plurality of boundary regions; as well as The third detection circuit is coupled to the first detection circuit and the second detection circuit. The first detection circuit and the second detection circuit receive the first signal from the third detection circuit.

13. The touch detection circuit of claim 12, wherein the touch detection circuit further comprises a touch controller coupled to the first detection circuit, the second detection circuit and the third detection circuit, wherein the touch controller performs touch detection on the touch area by means of a plurality of touch detection signals, and compares the first feedback signal with the second feedback signal to generate a total capacitance change between the plurality of boundary areas and the corresponding center area.

14. The touch detection circuit according to claim 13, wherein the touch controller comprises: Multiple first analog-to-digital converters are respectively coupled to the first detection circuit and the second detection circuit, and are configured to convert multiple feedback signals of the touch detection signal into multiple touch digital signals; Multiple first digital back-end circuits, each coupled to the first analog-to-digital converter, are configured to perform digital signal processing on the touch digital signal to generate multiple touch data; A second analog-to-digital converter, coupled to the third detection circuit, is configured to convert the first feedback signal and the second feedback signal into a plurality of first digital signals and a plurality of second digital signals. A second digital back-end circuit, coupled to the second analog-to-digital converter, is configured to perform digital signal processing on the plurality of first digital signals and the plurality of second digital signals to generate a plurality of first capacitor data and a plurality of second capacitor data. as well as The processor, coupled to the second digital back-end circuit, is configured to calculate the difference between the sum of the plurality of first capacitance data and the sum of the plurality of second capacitance data to generate the total capacitance change between the plurality of boundary regions and the corresponding central region.

15. The touch detection circuit according to claim 13, wherein the first detection circuit comprises: A plurality of first multiplexers are coupled to the touch panel, each of the first multiplexers being configured to select one of the touch detection signal, the first signal, and the second signal and transmit the one of the touch detection signal, the first signal, and the second signal to the touch panel; as well as A plurality of first operational amplifiers are provided, wherein a first input terminal of each of the first operational amplifiers is coupled to a corresponding first multiplexer in the first multiplexer, a second input terminal of each of the first operational amplifiers receives one of the touch detection signals, and an output terminal of each of the first operational amplifiers is coupled to a first input terminal of each of the first operational amplifiers. The first multiplexer transmits the touch detection signal to the touch area being touched in the touch area to receive multiple feedback signals of the touch detection signal, and transmits the first detection signal to the multiple boundary areas to receive the first feedback signal.

16. The touch detection circuit according to claim 13, wherein the second detection circuit comprises: A plurality of second multiplexers are coupled to the touch panel, each of the second multiplexers being configured to select one of the touch detection signal, the first signal, and the second signal and transmit the one of the touch detection signal, the first signal, and the second signal to the touch panel; as well as A plurality of second operational amplifiers are provided, each of which has a first input terminal coupled to a corresponding second multiplexer in the second multiplexer. Each of the second operational amplifiers has a second input terminal receiving one of the touch detection signals, and each of the second operational amplifiers has an output terminal coupled to the first input terminal of each of the second operational amplifiers. The second multiplexer transmits the touch detection signal to the touch area being touched in the touch area to receive multiple feedback signals of the touch detection signal, and transmits the second detection signal to the corresponding central area to receive the second feedback signal.

17. The touch detection circuit according to claim 13, wherein the third detection circuit comprises: A third multiplexer, coupled to the first detection circuit and the second detection circuit, is configured to receive the first feedback signal and the second feedback signal; as well as A third operational amplifier, wherein the first input terminal of the third operational amplifier is coupled to the third multiplexer, the second input terminal of the third operational amplifier receives the first signal, and the output terminal of the third operational amplifier is coupled to the first input terminal of the third operational amplifier. The third multiplexer transmits the first signal to the first detection circuit to receive the first feedback signal from the first detection circuit, and transmits the first signal to the second detection circuit to receive the second feedback signal from the second detection circuit.

18. The touch detection circuit according to claim 12, wherein the first signal is a DC voltage signal, and the second signal is a no-load drive signal in phase with the touch detection signal.

19. The touch detection circuit according to claim 12, wherein the first signal is a touch detection signal and the second signal is an inverted touch detection signal.

20. A touch detection method, applicable to a touch detection circuit coupled to a touch panel having multiple touch areas, wherein the touch detection circuit includes multiple first detection circuits, multiple second detection circuits, and a third detection circuit, and the touch areas include multiple boundary areas, the touch detection method comprising: Each of the first detection circuits selects one of the first signal and the second signal as one of a plurality of first detection signals; Each of the first detection circuits transmits one of the plurality of first detection signals to one of the plurality of boundary regions of the undetected touch area in the touch area to receive one of the plurality of first feedback signals; Each of the second detection circuits selects the first signal and another of the second signals as one of a plurality of second detection signals; as well as Each of the second detection circuits transmits one of the plurality of second detection signals to the corresponding central region of the undetected touch area to receive one of the plurality of second feedback signals, wherein the corresponding central region includes the undetected touch area excluding the plurality of boundary regions. The first signal is received from the third detection circuit.

21. The touch detection method according to claim 20, further comprising: Touch detection is performed on the touch area using multiple touch detection signals; as well as The first feedback signal is compared with the second feedback signal to generate the total capacitance change between the plurality of boundary regions and the corresponding central region.

22. The touch detection method according to claim 21, further comprising: The first feedback signal and the second feedback signal are converted into a plurality of first digital signals and a plurality of second digital signals; Digital signal processing is performed on the plurality of first digital signals and the plurality of second digital signals to generate a plurality of first capacitance data and a plurality of second capacitance data; as well as The difference between the sum of the plurality of first capacitance data and the sum of the plurality of second capacitance data is calculated to generate the total capacitance change between the plurality of boundary regions and the corresponding central region.

23. The touch detection method according to claim 21, further comprising: The touch detection signal is transmitted to the touch area being touched in the touch area to receive multiple feedback signals of the touch detection signal; The plurality of first detection signals are transmitted to the boundary region to receive the first feedback signal; as well as The plurality of second detection signals are transmitted to the corresponding central region to receive the second feedback signal.

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