Disc type pulley touch detection method applied to FPC (Flexible Printed Circuit)

Abstract

The invention belongs to the technical field of touch key detection, and particularly relates to a disc type pulley touch detection method applied to an FPC (Flexible Printed Circuit). Comprising the following steps: performing register initialization and double-frequency-point frequency hopping touch scanning to obtain a touch maximum value, a touch intermediate value and a touch minimum value of each key; taking the difference between the touch maximum value and the touch minimum value as a noise value of each key; comparing the noise values according to a preset noise judgment condition so as to judge whether the touch detection system is in a noise environment at present, and correspondingly setting or clearing a noise flag bit; selecting the touch intermediate value or the touch minimum value as a current effective touch value according to the noise flag bit; under the condition that no effective touch exists and the touch change is stable, the touch reference value of each key is slowly updated in a weighting mode; according to the invention, the problems of unstable pressing and sensitivity deviation of a touch pulley system are solved.

Description

Technical Field

[0001] This invention belongs to the field of touch button detection technology, and specifically relates to a disc-type pulley touch detection method applied to FPC flexible circuit boards. Background Technology

[0002] In recent years, capacitive touch button detection technology has developed rapidly worldwide, and touch buttons are gradually replacing traditional mechanical buttons, becoming a new choice in various button application fields. Compared with mechanical buttons, capacitive touch buttons only require a light touch of the finger to achieve sensitive and fast control response, while also having the advantages of no physical wear and strong sealing, making them suitable for a wider range of scenarios.

[0003] With the continuous expansion and deepening of touch interaction, basic touch button solutions are no longer sufficient to meet market demands in core application areas such as home appliances and automobiles. The market demand for touch interaction solutions that can achieve fine-tuning, such as scroll wheel touch and slider touch, is growing rapidly.

[0004] Most existing touch detection solutions use a single button to achieve one level adjustment; or they use a button board: using springs, conductive foam, or other media to connect the PCB board and the panel, with one PAD corresponding to one button, and the buttons are cascaded to form a pulley or slider effect.

[0005] However, the existing technology has the following main technical defects: 1) Current touch implementation methods are all implemented on rigid PCB circuit boards, which are highly limited, lack flexibility, and are not suitable for touch products with small space and structure; 2) The touch panel of the product must not have any components, otherwise it will affect the touch panel's fit and touch sensitivity. Display devices and ICs need to be arranged on both sides, increasing SMT costs; 3) Most methods of connecting the control board to the main control board require plug-in terminals, which limits the structural installation; 4) Using multiple cascaded buttons to achieve a scroll wheel effect results in poor scrolling performance and easy button loss. When a finger touches between two buttons, button jitter occurs, and the buttons may skip during relevant reliability tests. Summary of the Invention

[0006] The purpose of this invention is to provide a disc-type pulley touch detection method for FPC flexible circuit boards. Under the condition of meeting the sensitivity requirements, this invention adopts a dual-frequency point four-threshold detection method, which solves the problem of unstable tapping when the pulley system is sliding and is easy to pass relevant reliability tests.

[0007] To address the aforementioned technical problems, this invention provides a disc-type pulley touch detection method for FPC flexible circuit boards, comprising: By initializing the registers and performing dual-frequency hopping touch scanning, and by performing multiple sampling and filtering processes, the maximum touch value, the intermediate touch value, and the minimum touch value of each button are obtained. The noise value for each button is determined by the difference between the maximum and minimum touch values. The noise values ​​are compared according to preset noise judgment conditions to determine whether the touch detection system is currently in a noisy environment, and the noise flag is set or cleared accordingly. Based on the noise flag, the intermediate or minimum touch value is selected as the current valid touch value; under the condition that there is no valid touch and the touch change is stable, the touch reference value of each button is slowly updated in a weighted manner. Based on the noise flag bit, the preset threshold for each button is dynamically adjusted to form four judgment thresholds, including the maximum effective value of touch sliding, single key threshold, combination key threshold and minimum touch sliding value. By calculating the difference between the touch midpoint value of each button and the corresponding baseline value, and introducing a preset redundancy range, the button with the largest difference is determined as the reference point for touch position determination. Based on the reference point, the historical touch level recorded by the touch detection system, the difference between each button, and four judgment thresholds, a preset state judgment logic is executed to determine and output the current touch level. The state determination logic includes: When the historical gear position is a combination key gear position related to the reference point, the first determination sub-process is executed; the first determination sub-process includes: determining whether the difference between the other key constituting the combination key gear position and its corresponding minimum touch sliding value is greater than the minimum value; if yes, the combination key gear position is maintained; if no, the second determination sub-process is executed. When the historical gear position is a single-key gear position related to the reference point, a second determination sub-process is executed; the second determination sub-process includes: determining whether the difference of the reference point is greater than a single-key determination threshold; if yes, determining to maintain the single-key gear position corresponding to the historical gear position; if no, determining to be a no-touch gear position; wherein the single-key determination threshold is the single-key threshold corresponding to the reference point minus a preset redundancy amount; the preset redundancy amount is half of a preset noise threshold; When the historical gear state is a no-touch gear, a third determination sub-process is executed. The third determination sub-process includes: determining whether the difference between adjacent keys related to the reference point is greater than its corresponding combination key threshold; if yes, it is determined to be a combination key gear formed by the reference point and the adjacent key; if no, it is determined whether the difference between the adjacent keys is greater than its minimum touch sliding value, and whether the sum of the difference between the reference point and the difference between the adjacent keys is greater than the sum of their combination key thresholds; if yes, it is determined to be the corresponding combination key gear; determining whether the difference between the reference point is greater than its single key threshold; if yes, it is determined to be the single key gear corresponding to the reference point; if none of the above conditions are met, it is determined to be a no-touch gear.

[0008] Preferably, the dual-frequency hopping touch scanning, and the multiple sampling and filtering processes, include: scanning the four touch buttons in a circular layout using two different touch detection frequencies, obtaining the touch value of each button at the two different frequency points, and sampling it three times, marking it as the maximum value, minimum value and median value respectively, and averaging and first-order filtering the three data with the corresponding value from the previous sampling to obtain the maximum touch value, median touch value and minimum touch value of each button; wherein the touch detection frequencies are normally distributed and uniformly distributed, respectively.

[0009] Preferably, the preset noise determination conditions include: The noise flag position is activated when: in two consecutive scans, the number of buttons with noise values ​​greater than a preset noise threshold exceeds half of the total number of buttons, or in two consecutive scans, the noise value of the same button is greater than a preset noise threshold. In this case, the touch detection system is considered to be in a noisy environment and the noise flag position is activated. The noise flag is cleared when: if the noise value of all buttons is less than the preset noise threshold for 100 consecutive times without any buttons, or if the noise value of all buttons is less than the preset noise threshold for 300 consecutive times with buttons, the touch detection system is considered to be in a noise-free environment and the noise flag is cleared.

[0010] Preferably, if the touch detection system is in a noisy environment, the current valid touch value is the minimum value; if the touch detection system is not in a noisy environment, the current valid touch value is the intermediate value. The update of the touch reference value for each button must simultaneously meet the following conditions: Condition 1: The touch jitter value is less than a preset noise threshold; the touch jitter value is the difference between the current valid touch value and the previous valid touch value; Condition 2: There is currently no button pressed and no trend of button pressing, that is, the touch jitter value is less than the preset minimum touch change amount; After the above two conditions are met, the touch reference value is refreshed after a 1-second delay, and the touch reference value is updated according to the weighted formula "new touch reference value = original touch reference value × 3 / 4 + current effective touch value × 1 / 4".

[0011] Preferably, the preset threshold for each button is dynamically adjusted to form four judgment thresholds, including: When the noise flag indicates a non-noise environment, 120%, 70%, 30%, and 20% of the preset thresholds are taken as the maximum effective value of touch sliding, the single key threshold, the combination key threshold, and the minimum touch sliding value, respectively. When the noise flag indicates a noisy environment, 130%, 80%, 40%, and 30% of the preset thresholds are taken as the maximum effective value of touch sliding, the single key threshold, the combination key threshold, and the minimum touch sliding value, respectively.

[0012] Preferably, it also includes an anomaly protection step: if the difference between any key and the maximum effective value of the touch swipe is greater than the maximum effective value and lasts for a certain period of time, the system protection is triggered, and all touch outputs are reset.

[0013] Preferably, the touch settings include: four single-key settings corresponding to four independent touch buttons, four combination key settings corresponding to four adjacent touch buttons being triggered simultaneously, and one no-touch setting, for a total of nine button states.

[0014] Preferably, before executing the state determination logic, a validity verification step is also included: calculating the difference between the maximum and minimum touch values ​​of all buttons in the current scanning cycle; if the difference is less than twice the preset noise threshold, the touch is determined to be valid, and the state determination logic is executed; otherwise, the determination is abandoned.

[0015] The present invention also provides a disc-type pulley touch detection system for FPC flexible circuit boards, comprising: The touch-sensitive pulley consists of four touch buttons arranged in a disc-like layout, and is used to enable touch input for products with irregular shapes via a flexible circuit board. The processing control module is configured to execute a disc-type pulley touch detection method for FPC flexible circuit boards as described above.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention can be applied to products with irregularly shaped touch structures, minimizing restrictions on product appearance. It achieves eight levels of touch adjustment using only four buttons, supporting both sliding and tapping touches, both of which are stable and jitter-free. It supports 2mm air-to-touch operation, allowing for single-panel layout of components with the panel directly covering the components, reducing the cost of flexible circuit boards (SMTs). While meeting sensitivity requirements, it employs a dual-frequency, four-threshold detection method, combined with historical level guidance, effectively solving the recognition jitter problem at button boundaries during sliding. This achieves smooth transitions and stable locking between touch points, ensuring accurate tapping. It also resolves the instability issue of tapping during sliding in pulley systems and more easily meets EMI / CS certification requirements. Attached Figure Description

[0017] Figure 1 This is a flowchart of a touch detection method for a touch button provided by the present invention.

[0018] Figure 2 This is a flowchart of the touch wheel sliding positioning and single-key positioning method provided by the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0020] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a disc-type pulley touch detection method applied to FPC flexible circuit boards, specifically including the following steps: Step 301: Initialize the registers used by the touch button module to provide a basic state.

[0021] Step 302: Two different touch detection frequencies are used for touch scanning, with normal and uniform distributions respectively. This frequency hopping method can effectively reduce the impact of strong interference at fixed frequencies on the original touch data, and at the same time reduce the radiation interference generated to the outside.

[0022] Step 303: Take the touch value of a touch button at different frequencies, sample it three times, and mark it as the maximum value, minimum value and median value respectively.

[0023] Step 304: Average the maximum, median, and minimum touch values ​​obtained from the two different touch detection frequencies with the previous values, perform first-order filtering, and obtain new median and minimum values ​​for subsequent button state determination.

[0024] Step 305: Noise Assessment. The maximum and minimum touch values ​​at the two frequency points are calculated separately, and the difference between them is recorded as the noise value. This noise value is then compared with the noise value obtained beforehand using the touch calibration software.

[0025] The noise value and noise determination criteria are set as follows: ① If the number of buttons whose noise value exceeds the preset noise value exceeds 1 / 2 of the total number of buttons in two consecutive instances, the system is considered to be in a noisy environment, and the noise flag position is activated.

[0026] ② If the noise value of the same button exceeds the preset noise value twice in a row, the system is considered to be in a noisy environment, and the noise flag position is activated.

[0027] ③ If, under no-button conditions, the noise value of all buttons is less than the preset noise value for 100 consecutive presses, the system is considered to be in a noise-free environment, and the noise flag is cleared to 0.

[0028] ④ If the noise value of all buttons is less than the preset noise value after 300 consecutive key presses, the system is considered to be in a noise-free environment, and the noise flag is cleared to 0.

[0029] Step 306: Baseline Value Update. If the system is not in a noisy environment, the touch value uses the median value; if the system is in a noisy environment, the touch value uses the minimum value. Obtain the difference between the current touch value and the previous touch value, and record it as the touch jitter value. The baseline value update must meet the following two conditions: 1) The touch jitter value is less than the preset noise value; 2) There is currently no button pressed and no trend of button pressing (the touch jitter value is less than the preset minimum touch change).

[0030] After meeting the above two conditions, the baseline value is refreshed after a 1-second delay to ensure the stability of the touch scroll wheel effect during reliability testing. The new baseline value is 3 / 4 of the original baseline value plus 1 / 4 of the existing touch value, allowing the baseline value to update slowly and maintaining the stability of the entire touch system.

[0031] Step 307: Calculation of Four Thresholds. First, obtain the threshold for each button using the touch debugging software. Then, consider the following two cases based on whether the system is in a noisy environment: 1) In a non-noisy environment: 120%, 70%, 30%, and 20% of the threshold are recorded as the maximum effective touch sliding value, single-key threshold, combination key threshold, and minimum touch sliding value, respectively. 2) In a noisy environment: 130%, 80%, 40%, and 30% of the threshold are recorded as the maximum effective touch sliding value, single-key threshold, combination key threshold, and minimum touch sliding value, respectively.

[0032] Step 308: Key Count Determination. First, determine whether it is a single key press, a combination key press, or a trend of three or more key presses. If a single key or combination key press is detected, proceed to step 309; if three or more key presses are detected or no key presses are detected, proceed to step 302.

[0033] Step 309: Key Locking and Initial Judgment. Scan all keys, subtract the median touch value of each of the two frequency points from the corresponding base value to obtain the difference. Subtract half of the preset noise value from the obtained difference, denoted as differenceData_comp[cnt], to create a redundant interval for touch position determination, which can avoid jitter at the junction of combination keys. Obtain the key with the largest touch difference and mark it as diffMaxPoint. The maximum touch difference is denoted as diffDataMax. At the same time, calculate the difference between the maximum touch value and the minimum touch value, denoted as tk_differ. If tk_differ is less than twice the preset noise value, the touch is determined to be valid, and the process jumps to step 310. If tk_differ is greater than or equal to twice the preset noise value, the process jumps to step 302.

[0034] Step 310: Position Calculation. Label the four buttons forming the pulley as TK1, TK2, TK3, and TK4. The eight positions of the pulley are TK1, TK1+TK2, TK2, TK2+TK3, TK3, TK3+TK4, TK4, and TK4+TK1. TK1 corresponds to position 1, TK1+TK2 to position 2, TK2 to position 3, TK2+TK3 to position 4, TK3 to position 5, TK3+TK4 to position 6, TK4 to position 7, and TK4+TK1 to position 8. No button corresponds to position 0. The button with the largest maximum difference has been determined in step 309. If diffMaxPoint is TK1, the previous position state associated with TK1 could only be one of four states: 0 (no button), 1 (TK1), 2 (TK1+TK2), or 8 (TK4+TK1). First, determine if the current position is 8. If it is 8, jump to step 311; otherwise, jump to step 313.

[0035] Step 311: Calculate whether the difference TK4 value differData_comp[4] is greater than the minimum touch swipe value. If it is greater than the minimum touch swipe value, obtain position 8; otherwise, jump to step 312.

[0036] Step 312: Obtain position 0.

[0037] Step 313: Determine if the current position is 2. If it is 2, proceed to step 314; otherwise, proceed to step 315.

[0038] Step 314: Calculate whether the difference TK2 value differData_comp[2] is greater than the minimum touch swipe value. If it is greater than the minimum touch swipe value, obtain position 2; otherwise, jump to step 312.

[0039] Step 315: Determine if the current position is 1. If it is 1, proceed to step 316; otherwise, proceed to step 317.

[0040] Step 316: Calculate whether the TK1 difference value differData_comp[1] is greater than (TK1 single-key threshold - 1 / 2 preset noise value). If it is greater than (TK1 single-key threshold - 1 / 2 preset noise value), then obtain position 1; otherwise, jump to step 312.

[0041] Step 317: Determine if the current position is 0. If it is 0, it means no key is pressed or the previous key has been released. Only when the current key is 0 can the system continue to detect whether the next key is pressed, ensuring that there is no jitter when sliding the key, whether it is a single key or a combination key, thus improving the reliability of the scroll wheel detection system. If the current position is 0, proceed to step 318; otherwise, proceed to step 319.

[0042] Step 318: Determine whether the TK1 difference value differData_comp[1] is less than (TK1 single key threshold - 1 / 2 preset noise value). The purpose is to determine whether the TK1 key has a tendency to be released. If it is less than (TK1 single key threshold - 1 / 2 preset noise value), then jump to step 320; otherwise, jump to step 319.

[0043] Step 319: Exit this position determination and proceed to step 325.

[0044] Step 320: Determine whether the TK4 difference value differData_comp[4] is greater than the TK4 key combination threshold. If it is greater than the TK4 key combination threshold, obtain position 8; otherwise, jump to step 321.

[0045] Step 321: Determine whether the TK4 difference value differData_comp[4] is greater than the minimum threshold for TK4 touch swipe, and whether the sum of the TK4 difference value and the TK1 difference value (differData_comp[4] + differData_comp[1]) is greater than the sum of the TK4 key combination threshold and the TK1 key combination threshold. If both conditions are met, obtain position 8; otherwise, proceed to step 322.

[0046] Step 322: Determine whether the difference value differData_comp[2] of TK2 is greater than the TK2 key threshold. If it is greater than the TK2 key threshold, obtain position 2; otherwise, jump to step 323.

[0047] Step 323: Determine whether the difference value of TK2, differData_comp[2], is greater than the minimum threshold value of TK2 touch swipe, and whether the sum of the differences between TK1 and TK2 (differData_comp[1] + differData_comp[2]) is greater than the sum of the threshold values ​​of TK1 and TK2 combination keys. If both conditions are met, obtain position 2; otherwise, proceed to step 324.

[0048] Step 324: Determine whether the difference value differData_comp[1] of TK1 is greater than the TK1 single-key threshold. If it is greater than the TK1 single-key threshold, obtain position 1; otherwise, jump to step 319.

[0049] Step 325: Determine whether the difference value of all buttons, differData_comp[cnt], is greater than the maximum valid value of touch sliding. If a button's difference value is greater than the maximum valid value of touch sliding for 1 minute, the protection mechanism is triggered, all touch outputs are cleared to 0, and the process jumps to step 302.

[0050] In summary, the improved four-threshold filtering algorithm and dual-frequency point determination method for touch button presses in this invention can perfectly solve the problems of unstable touch and sensitivity deviation in touch roller systems, and can also pass relevant reliability tests in strong magnetic interference scenarios.

[0051] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A disc-type pulley touch detection method applied to FPC flexible circuit boards, characterized in that, include: By initializing the registers and performing dual-frequency hopping touch scanning, and by performing multiple sampling and filtering processes, the maximum touch value, the intermediate touch value, and the minimum touch value of each button are obtained. The difference between the maximum and minimum touch values ​​is used as the noise value for each button. Based on preset noise judgment conditions, the noise values ​​are compared to determine whether the touch detection system is currently in a noisy environment, and the noise flag is set or cleared accordingly. Based on the noise flag, the intermediate or minimum touch value is selected as the current valid touch value; Under the condition that there is no effective touch and the touch changes are stable, the touch reference value of each button is slowly updated in a weighted manner; Based on the noise flag bit, the preset threshold for each button is dynamically adjusted to form four judgment thresholds, including the maximum effective value of touch sliding, single key threshold, combination key threshold and minimum touch sliding value. By calculating the difference between the touch midpoint value of each button and the corresponding baseline value, and introducing a preset redundancy range, the button with the largest difference is determined as the reference point for touch position determination. Based on the reference point, the historical touch level recorded by the touch detection system, the difference between each button, and four judgment thresholds, a preset state judgment logic is executed to determine and output the current touch level. The state determination logic includes: When the historical gear position is a combination key gear position related to the reference point, the first determination sub-process is executed; the first determination sub-process includes: determining whether the difference between the other key constituting the combination key gear position and its corresponding minimum touch sliding value is greater than the minimum value; if yes, the combination key gear position is maintained; if no, the second determination sub-process is executed. When the historical gear position is a single-key gear position related to the reference point, a second determination sub-process is executed; the second determination sub-process includes: determining whether the difference of the reference point is greater than a single-key determination threshold; if yes, determining to maintain the single-key gear position corresponding to the historical gear position; if no, determining to be a no-touch gear position; wherein the single-key determination threshold is the single-key threshold corresponding to the reference point minus a preset redundancy amount; the preset redundancy amount is half of a preset noise threshold; When the historical gear state is a no-touch gear, a third determination sub-process is executed; the third determination sub-process includes: determining whether the difference between adjacent keys related to the reference point is greater than its corresponding combination key threshold; if yes, it is determined to be a combination key gear formed by the reference point and the adjacent key; if no, it is determined whether the difference between the adjacent keys is greater than its minimum touch sliding value, and whether the sum of the difference between the reference point and the difference between the adjacent keys is greater than the sum of their combination key thresholds; if yes, it is determined to be the corresponding combination key gear; determining whether the difference between the reference point is greater than its single key threshold; if yes, it is determined to be the single key gear corresponding to the reference point; if none of the above conditions are met, it is determined to be a no-touch gear.

2. The disc-type pulley touch detection method for FPC flexible circuit boards as described in claim 1, characterized in that, The dual-frequency hopping touch scanning, and the multiple sampling and filtering processes, include: scanning the four touch buttons in a circular layout using two different touch detection frequencies, obtaining the touch value of each button at the two different frequency points, and sampling it three times, marking it as the maximum value, minimum value and median value respectively. The three data are then averaged and first-order filtered with the corresponding value from the previous sampling to obtain the maximum touch value, median touch value and minimum touch value of each button; wherein the touch detection frequencies are normally distributed and uniformly distributed, respectively.

3. The disc-type pulley touch detection method for FPC flexible circuit boards as described in claim 1, characterized in that, The preset noise determination conditions include: The noise flag position is activated when: in two consecutive scans, the number of buttons with noise values ​​greater than a preset noise threshold exceeds half of the total number of buttons, or in two consecutive scans, the noise value of the same button is greater than a preset noise threshold. In this case, the touch detection system is considered to be in a noisy environment and the noise flag position is activated. The noise flag is cleared when: if the noise value of all buttons is less than the preset noise threshold for 100 consecutive times without any buttons, or if the noise value of all buttons is less than the preset noise threshold for 300 consecutive times with buttons, the touch detection system is considered to be in a noise-free environment and the noise flag is cleared.

4. The disc-type pulley touch detection method for FPC flexible circuit boards as described in claim 1, characterized in that, If the touch detection system is in a noisy environment, the minimum value is used for the current valid touch value; if the touch detection system is not in a noisy environment, the intermediate value is used for the current valid touch value. The update of the touch reference value for each button must simultaneously meet the following conditions: Condition 1: The touch jitter value is less than a preset noise threshold; the touch jitter value is the difference between the current valid touch value and the previous valid touch value; Condition 2: There is currently no button pressed and no trend of button pressing, that is, the touch jitter value is less than the preset minimum touch change amount; After the above two conditions are met, the touch reference value is refreshed after a 1-second delay, and the touch reference value is updated according to the weighted formula "new touch reference value = original touch reference value × 3 / 4 + current effective touch value × 1 / 4".

5. The disc-type pulley touch detection method for FPC flexible circuit boards as described in claim 1, characterized in that, The preset threshold for each button is dynamically adjusted to form four judgment thresholds, including: When the noise flag indicates a non-noise environment, 120%, 70%, 30%, and 20% of the preset thresholds are taken as the maximum effective value of touch sliding, the single key threshold, the combination key threshold, and the minimum touch sliding value, respectively. When the noise flag indicates a noisy environment, 130%, 80%, 40%, and 30% of the preset thresholds are taken as the maximum effective value of touch sliding, the single key threshold, the combination key threshold, and the minimum touch sliding value, respectively.

6. The disc-type pulley touch detection method for FPC flexible circuit boards as described in claim 1, characterized in that, It also includes an anomaly protection step: if the difference between any key and the maximum effective value of the touch swipe is greater than the maximum effective value and lasts for a certain period of time, the system protection is triggered, and all touch outputs are reset.

7. The disc-type pulley touch detection method for FPC flexible circuit boards as described in claim 1, characterized in that, The touch settings include: four single-key settings corresponding to four independent touch buttons, four combination key settings corresponding to four adjacent touch buttons being triggered simultaneously, and one no-touch setting, for a total of nine button states.

8. The disc-type pulley touch detection method for FPC flexible circuit boards as described in claim 1, characterized in that, Before executing the state determination logic, a validity verification step is also included: calculate the difference between the maximum and minimum touch values ​​of all buttons in the current scanning cycle. If the difference is less than twice the preset noise threshold, the touch is determined to be valid, so as to execute the state determination logic. Otherwise, this judgment will be abandoned.

9. A disc-type pulley touch detection system for FPC flexible circuit boards, characterized in that, include: The touch-sensitive pulley consists of four touch buttons arranged in a disc-like layout, and is used to enable touch input for products with irregular shapes via a flexible circuit board. The processing control module is configured to perform a disc-type pulley touch detection method for FPC flexible circuit boards as described in any one of claims 1 to 8.

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