Noise detection method and applicable touch display device thereof

Abstract

The invention provides a noise detection method and a touch display device applicable to the noise detection method. Charging noise introduced by finger pressing can be separated. The noise detection method includes the following steps. A noise detection action is performed on the plurality of touch sensing channels to obtain first noise information. And obtaining a touched state of each touch sensing channel. When the touched state of the touch sensing channel is a pressed state, noise information corresponding to the touch sensing channel is removed, and second noise information is obtained; and calculating the first noise information and the second noise information to obtain noise information without the influence of the charging noise and the charging noise.

Description

Technical Field

[0001] This invention relates to a detection method, and more particularly to a noise detection method and a touch display device to which it is applicable. Background Technology

[0002] Generally, touch display devices perform noise detection at specific intervals. Based on the noise intensity, the touch display device determines whether to adjust the frequency band of the touch sensing operation and thereby improves the signal quality of the operation.

[0003] However, during noise detection, when a finger presses (including clicks or swipes) on the touch display device, additional noise (including charging noise) is introduced into the touch display device due to the newly added conductive path between the finger and the device. Therefore, the touch display device may misjudge the noise intensity. Consequently, the touch display device cannot accurately detect its own background noise, thus affecting the judgment criteria for adjusting frequency bands. Summary of the Invention

[0004] This invention provides a noise detection method applicable to touch display devices, which can separate charging noise introduced by finger pressing, thereby improving the accuracy of noise detection.

[0005] The noise detection method of this invention includes the following steps: Performing noise detection on multiple touch sensing channels to obtain first noise information; obtaining the touch-controlled state of each touch sensing channel; when the touch-controlled state of each touch sensing channel is a pressed state, removing the noise information corresponding to this touch sensing channel and obtaining second noise information; calculating the first noise information and the second noise information to obtain noise information unaffected by charging noise and charging noise.

[0006] This invention also provides a touch display device. The touch display device includes a touch display panel and a controller. The touch display panel includes a plurality of touch sensing channels. The controller is coupled to the touch display panel and the plurality of touch sensing channels. The controller performs noise detection on the plurality of touch sensing channels to obtain first noise information. The controller obtains the touched state of each touch sensing channel. When the touched state of each touch sensing channel is a pressed state, the controller removes the noise information corresponding to that touch sensing channel and obtains second noise information. The controller calculates the first noise information and the second noise information to obtain noise information unaffected by charging noise and charging noise.

[0007] Based on the above, the noise detection method and the applicable touch display device of this invention remove noise information obtained by the touch sensing channel based on the pressed state of each touch sensing channel, thereby separating the noise information detected by finger pressing from all noise information. Thus, the noise detection method can separate the charging noise introduced by finger pressing from the execution result of the noise detection action, thereby improving the accuracy of noise detection.

[0008] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0009] Figure 1 This is a circuit block diagram of a touch display device according to an embodiment of the present invention;

[0010] Figure 2 This is a flowchart of a noise detection method according to an embodiment of the present invention;

[0011] Figure 3 This is a flowchart of a noise detection method according to another embodiment of the present invention;

[0012] Figure 4 Based on the present invention Figure 3 The embodiment shows a schematic diagram of the operation of recording charging noise and displaying noise;

[0013] Figures 5A to 5B Based on the present invention Figure 3 The embodiment shows a schematic diagram of the display noise being adjusted before and after noise detection;

[0014] Figures 6A to 6C Based on the present invention Figure 3 The embodiment shows a schematic diagram of the operation during the adjustment of noise detection.

[0015] Explanation of icon numbers

[0016] 100: Touch display device;

[0017] 110: Controller;

[0018] 120: Touch display panel;

[0019] 121~12N, 1231~1233: Touch sensing channels;

[0020] FN-1~FN+1: Chart frame period;

[0021] FG: finger;

[0022] Hsync: Horizontal synchronization signal;

[0023] MC, RXSC, TXSC: During touch detection;

[0024] NL: During noise detection;

[0025] P1: Indicator;

[0026] S210~S240, S310~S380: Steps;

[0027] SG1~SG2: ​​During touch sensing;

[0028] TE: Enable signal;

[0029] V1~V2: Voltage values;

[0030] Vsync: Vertical synchronization signal;

[0031] X, Y: Direction. Detailed Implementation

[0032] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same component reference numerals are used in the drawings and description to denote the same or similar parts.

[0033] Figure 1 This is a circuit block diagram of a touch display device according to an embodiment of the present invention. (Reference) Figure 1 The touch display device 100 can eliminate noise caused by external factors (e.g., charging noise introduced by finger pressing and / or display noise introduced by screen content) and detect valid noise (e.g., background noise of the touch display device 100 itself). The touch display device 100 can perform touch algorithms based on valid noise to accurately avoid, compensate for or eliminate noise interference with touch information, and thereby realize touch function.

[0034] The touch display device 100 includes a controller 110 and a touch display panel 120. The touch display panel 120 includes a plurality of touch sensing channels 121-12N, where N is a positive integer. These touch sensing channels 121-12N are arranged sequentially in the Y direction and include a plurality of touch sensing electrodes. That is, the plurality of touch sensing electrodes can be arranged in a matrix. The plurality of touch sensing channels 121-12N are used to perform mutual capacitive touch detection and / or self-capacitive touch detection to output corresponding touch data to the controller 110.

[0035] The controller 110 is coupled to the touch display panel 120 and also coupled to a plurality of touch sensing channels 121-12N disposed in the touch display panel 120 and a display layer (not shown). The controller 110 is used to drive the pixel circuits shared by the multiple pixel circuits in the display layer (not shown) to realize the display function. The controller 110 is also used to drive the plurality of touch sensing channels 121-12N to realize the touch function. The controller 110 may be, for example, a display driver integrated circuit (DDIC) or a touch and display driver integration circuit (TDDI).

[0036] Figure 2 This is a flowchart illustrating a noise detection method according to an embodiment of the present invention. (See reference) Figure 1 as well as Figure 2 The touch display device 100 executes steps S210-S230 within a specific cycle via the controller 110 to perform a noise detection method. The cycle may be, for example, a noise detection period operating during touch sensing, and staggered from the touch detection period within the touch sensing period. The touch detection period may be, for example, the period during which multiple touch sensing channels 121-12N perform touch detection actions to output touch data.

[0037] In step S210, the controller 110 performs noise detection on the multiple touch sensing channels 121~12N to obtain noise information (i.e., first noise information) of the multiple touch sensing channels respectively. The noise detection action instructs the multiple touch sensing channels 121~12N to be driven so as to output multiple data as the first noise information respectively.

[0038] In step S220, the controller 110 obtains the touched state of each touch sensing channel 121-12N. The touched state may be, for example, the result of touch data calculation during touch detection. The touched state may be, for example, a pressed state, indicating that finger FG is pressing the corresponding touch sensing channel 1231-1233. Alternatively, the touched state may be, for example, an unpressed state, indicating that no finger FG is pressing the corresponding touch sensing channel (including touch sensing channels 121-122 and 12N).

[0039] In step S230, when any of the touch sensing channels 121-12N is in a pressed state, the controller 110 removes the noise information corresponding to these touch sensing channels 121-12N and obtains second noise information. Specifically, the controller 110 accesses the noise information provided by one or more touch sensing channels (e.g., touch sensing channels 1231-1233) in a pressed state, and removes the noise information from the first noise information of the plurality of touch sensing channels in step S210. The removed noise information includes charging noise introduced by pressing the finger FG.

[0040] In step S240, when the device is not pressed, the controller 110 treats the first noise information as noise information unaffected by charging noise. When the device is pressed, it calculates the first noise information and the second noise information to obtain noise information unaffected by charging noise and charging noise. In this way, the touch display device 100 can separate different noise information (including charging noise and other noise) and improve the accuracy of the touch function.

[0041] Figure 3 This is a flowchart illustrating a noise detection method according to another embodiment of the present invention. (See reference) Figure 1 as well as Figure 3 The touch display device 100 executes steps S310 to S380 via the controller 110 to perform the noise detection method.

[0042] In step S310, the controller 110 initializes the noise detection action to set the range and frequency band of the noise detection action. The range may be, for example, all touch display areas of the touch display panel 120. The frequency band may be, for example, various frequency points from the first frequency to the second frequency.

[0043] In step S320, the controller 110 performs noise detection on all touch sensing channels 121~12N to obtain noise information of each touch sensing channel 121~12N as first noise information. The controller 110 also stores the touched state (including pressed state and / or unpressed state) of each touch sensing channel 121~12N.

[0044] In step S330, the controller 110 obtains the touch-sensitive state of each touch sensing channel 121-12N and determines whether each touch sensing channel 121-12N is pressed. When there is a pressed touch sensing channel (e.g., touch sensing channels 1231-1233) on the touch display panel 120, it indicates that the first noise information contains charging noise introduced by the finger FG pressing the touch display panel 120. The controller 110 continues with steps S341-S342. Otherwise, the controller 110 continues with step S342.

[0045] In step S341, the controller 110 removes the noise information corresponding to the touch sensing channels (e.g., touch sensing channels 1231-1233) that are in a pressed state from the first noise information, and obtains the second noise information based on the remaining noise information. The first noise information is all the noise collected by the touch sensing channels 121-12N, that is, the noise information affected by charging noise, including background noise, charging noise, and display noise caused by the display layer. The second noise information is the other noise after removing the charging noise, that is, the noise information unaffected by charging noise, including background noise and display noise.

[0046] In step S342, the controller 110 detects the display noise of the touch sensing channels 121~12N corresponding to the current screen. In some scenarios, the controller 110 can calculate the display noise of the current screen based on the noise information of the touch sensing channels 121~12N corresponding to the screen without updates and the noise information of the touch sensing channels 121~12N corresponding to the current screen.

[0047] Please refer to the above. Figure 4 , Figure 4 Based on the present invention Figure 3 A schematic diagram illustrating noise information recorded during charging is shown in the embodiment. Figure 4 In the diagram, the horizontal axis represents the frequency points, and the vertical axis represents the noise energy.

[0048] like Figure 4 As shown, the noise energy of the first noise information can be represented by the average of the noise information corresponding to all touch sensing channels 121-12N at each frequency point. At frequency points 8-10, charging noise is introduced into the touch display panel 120 because the finger FG presses the touch sensing channels 1231-1233. Thus, the noise energy of the first noise information at index P1 (i.e., frequency points 8-10) is higher than the noise energy at other neighboring frequency points. At frequency points 20-23 and 31-32, other reasons besides finger FG pressing cause the noise energy of the first noise information to be higher than the noise energy at other neighboring frequency points. Other reasons are not within the scope of discussion in this embodiment, so related discussions are omitted.

[0049] The difference between the first noise information and the second noise information is the interference caused by charging noise. Thus, the controller 110 calculates the charging noise based on the difference between the first noise information and the second noise information.

[0050] Back Figure 3In step S350, the controller 110 determines, based on the display noise obtained in step S342, whether the display data difference between adjacent data lines is greater than a threshold, in order to determine whether the touch display panel 120 displays a specific pattern that interferes with the noise value. The multiple data lines are multiple metal lines disposed in the display layer and used to transmit display data to multiple pixel circuits. The display data difference is the difference between the display data of two adjacent data lines, indicating the grayscale difference between adjacent display areas. When the display data difference is greater than the threshold, for example, when the display data has a black-and-white boundary pattern, the display data of the corresponding multiple data lines has a large voltage difference. Thus, the parasitic capacitance between the display layer and the cathode layer will cause additional display noise and affect the noise value.

[0051] In step S360, when the difference in displayed data between multiple adjacent data lines exceeds a threshold, the controller 110 adjusts the noise detection period. In this way, the controller 110 can stagger the execution period of the noise detection action from the period of displaying a specific pattern, thereby avoiding noise interference caused by the difference in displayed data. The controller 110 then executes step S342 again.

[0052] On the other hand, when the difference in displayed data between multiple data lines is not greater than the threshold, it indicates that the grayscale difference between multiple adjacent display areas is within a reasonable range and will not cause excessive display noise. Controller 110 continues step S370.

[0053] In step S370, when the device is not pressed, the controller 110 uses the first noise information as noise information unaffected by charging noise. When the device is pressed, it calculates the first noise information and the second noise information to obtain noise information unaffected by charging noise and charging noise. Furthermore, the controller 110 also records display noise that does not exceed a threshold value in step S350.

[0054] In step S380, the controller 110 reports the calculated noise information (including charging noise, display noise, and background noise) to the touch module (not shown). The touch module performs a touch algorithm based on the charging noise, display noise, and background noise to accurately avoid, compensate for, or eliminate noise interference with the touch information.

[0055] Figures 5A to 5B Based on the present invention Figure 3 The embodiment illustrates the operation of the display noise before and after adjustment during noise detection. (Reference) Figure 3 as well as Figures 5A to 5B ,exist Figures 5A to 5B In the diagram, the horizontal axis represents the frequency points, and the vertical axis represents the noise energy.

[0056] like Figure 5AAs shown, before adjustment during noise detection, the excessive grayscale difference in the displayed data causes parasitic capacitance to be generated in multiple data lines in the display layer relative to the shared cathode layer, thus introducing display noise. Consequently, in the energy distribution of the display noise, the noise energy at each frequency point is raised away from the minimum energy (i.e., 0), resulting in significant noise energy. In other words, display data differences exceeding a threshold are introduced into the display noise, causing noise distortion.

[0057] On the other hand, such as Figure 5B As shown, after adjustment during noise detection, since the display noise has avoided display data with excessive grayscale differences, the display noise energy distribution simply includes the display noise of the touch display panel 120 itself. Thus, apart from the frequency points corresponding to the display data and multiple frequency points corresponding to the harmonics of the display data, the display noise does not have significant noise energy.

[0058] Figures 6A to 6C Based on the present invention Figure 3 A schematic diagram illustrating the actions during noise detection is shown in the embodiment. (Reference) Figure 3 as well as Figures 6A to 6C The controller 110 operates in multiple frame cycles FN-1 to FN+1, and examples illustrate the details of how to adjust the noise detection process during step S360. Figures 6A to 6C In the diagram, the horizontal axis represents time, and the vertical axis represents voltage.

[0059] like Figure 6A As shown, controller 110 begins operation in a single frame cycle (e.g., frame cycle FN) based on the first falling edge of enable signal TE. Controller 110 terminates operation in this frame cycle FN based on the second falling edge of enable signal TE. Enable signal TE may, for example, switch between a first voltage value V1 and a second voltage value V2. The first voltage value V1 may, for example, be a high logic level. The second voltage value V2 may, for example, be a low logic level.

[0060] Each frame cycle (e.g., frame cycle FN) includes one or more touch sensing periods SG1-SG2. During each touch sensing period SG1-SG2 of frame cycle FN, controller 110 applies a vertical synchronization signal Vsync and a horizontal synchronization signal Hsync to a plurality of touch sensing channels 121-12N to enable these touch sensing channels 121-12N to perform touch detection and noise detection operations. The vertical synchronization signal Vsync and the horizontal synchronization signal Hsync may, for example, switch between a first voltage value V1 and a second voltage value V2.

[0061] Specifically, during the frame period FN, multiple touch sensing channels 121-12N operate in the touch sensing period SG1 according to a first time length following the rising or falling edge of the vertical synchronization signal Vsync, to generate corresponding touch data and noise information. The multiple touch sensing channels 121-12N also operate in the touch sensing period SG2 according to a second time length following the rising or falling edge of the vertical synchronization signal Vsync, to generate corresponding touch data and noise information. The second time length is longer than the first time length. Each time length can be, for example, multiple pulse lengths of the horizontal synchronization signal Hsync.

[0062] During each touch sensing period (e.g., touch sensing period SG1), the controller 110 uses the horizontal synchronization signal Hsync as a frequency signal. Based on multiple pulses of the horizontal synchronization signal Hsync, the controller 110 sequentially performs multiple touch detection actions and noise detection actions on the multiple touch sensing channels 121~12N during multiple touch detection periods MC, RXSC, and TXSC, and during a noise detection period NL.

[0063] During touch detection (MC), controller 110 performs mutual capacitance touch detection on multiple touch sensing channels 121-12N to obtain touch data in mutual capacitance mode. During touch detection (RXSC and TXSC), controller 110 performs self-capacitive touch detection on multiple touch sensing channels 121-12N to obtain touch data from multiple receiving electrodes in self-capacitive mode. During noise detection (NL), controller 110 performs noise detection on multiple touch sensing channels 121-12N to obtain multiple noise information. Thus, based on... Figure 3 In the operations of steps S310 to S360, within the same frame period FN, the controller 110 acquires multiple first noise information detected during different touch sensing periods SG1 to SG2.

[0064] like Figure 6A As shown, taking touch sensing period SG1 as an example, when the difference in displayed data between multiple adjacent data lines exceeds a threshold, controller 110 adjusts the noise detection period NL in period SG1. Specifically, during the noise detection operation, controller 110 marks the time point when the difference in displayed data occurs. This time point may overlap with the noise detection period NL. Controller 110 changes the weight value corresponding to the first noise information obtained in the noise detection period NL. That is, controller 110 reduces or ignores the first noise information obtained in the noise detection period NL of touch sensing period SG1. Thus, controller 110 prioritizes the first noise information obtained in touch sensing period SG2 as valid noise.

[0065] Or, such as Figure 6B As shown, when the difference in displayed data between multiple adjacent data lines exceeds a threshold, the controller 110 delays the noise detection period NL at the start time point of the touch sensing period SG1. Thus, the noise detection period NL can be staggered from the time period used to display a specific pattern (e.g., a black-and-white boundary pattern). In this embodiment, the delay time length of the start time point of the noise detection period NL is equal to the pulse length of the horizontal synchronization signal Hsync. The delay time length does not overlap with other touch sensing periods SG2.

[0066] Or, such as Figure 6C As shown, when the difference in displayed data between multiple adjacent data lines exceeds a threshold, the controller 110 changes the execution order of the noise detection period NL within the touch sensing period SG1. Thus, the noise detection period NL can be staggered from the time period used to display a specific pattern (e.g., a black-and-white boundary pattern). In this embodiment, the changed execution order within the touch sensing period SG1 sequentially includes the noise detection action within the noise detection period NL, and multiple touch detection actions within the multiple touch detection periods MC, RXSC, and TXSC, respectively.

[0067] In summary, the noise detection method and the applicable touch display device of this invention can separate charging noise introduced by finger pressing by calculating a portion of the noise information output by the touch sensing channel in the pressed state. By adjusting the noise detection period, the noise detection method can also avoid display noise introduced by excessive grayscale differences in the displayed data. Thus, the noise detection method can distinguish between charging noise introduced by finger pressing, display noise introduced by the screen content, and background noise of the touch display panel itself to obtain effective noise, thereby improving the accuracy of noise detection and subsequent touch functions.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A noise detection method, applicable to touch display devices, characterized in that, The noise detection method includes: Noise detection is performed on multiple touch sensing channels to obtain initial noise information; Obtain the touch-controlled state of each of the aforementioned touch sensing channels; When the touch-sensitive state of each of the touch sensing channels is a pressed state, the noise information corresponding to each of the touch sensing channels is removed, and second noise information is obtained; and The first noise information and the second noise information are calculated to obtain noise information without the influence of charging noise, as well as charging noise.

2. The noise detection method according to claim 1, characterized in that, The first noise information includes display noise, charging noise, and background noise, and the second noise information includes display noise and background noise.

3. The noise detection method according to claim 1, characterized in that, The steps of performing the noise detection operation on the plurality of touch sensing channels to obtain the plurality of noise information respectively include: During each touch sensing period of the frame cycle, a vertical synchronization signal and a horizontal synchronization signal are applied to the plurality of touch sensing channels; and The noise detection action is performed during the noise detection period in each of the aforementioned touch sensing periods.

4. The noise detection method according to claim 3, characterized in that, Also includes: Detect display noise of the multiple touch sensing channels corresponding to the current screen; as well as Based on the display noise corresponding to the current screen, determine whether the display data difference between multiple adjacent data lines is greater than a threshold in order to adjust the noise detection period.

5. The noise detection method according to claim 4, characterized in that, Also includes: When the difference in the displayed data is greater than the threshold, the start time point of the noise detection period in each of the touch sensing periods is delayed.

6. The noise detection method according to claim 5, characterized in that, The delay time length of the starting time point during the noise detection period is equal to the length of multiple pulses of the horizontal synchronization signal.

7. The noise detection method according to claim 4, characterized in that, Also includes: When the difference in the displayed data is greater than the threshold, the weight value corresponding to the first noise information obtained during the noise detection is changed.

8. The noise detection method according to claim 4, characterized in that, Also includes: During each of the aforementioned touch sensing periods, multiple touch detection actions and noise detection actions are sequentially performed on the plurality of touch sensing channels; as well as When the difference in the displayed data is greater than the threshold, the execution order of the noise detection period in each of the touch sensing periods is changed.

9. A touch display device, characterized in that, include: The touch display panel includes multiple touch sensing channels; as well as The controller, coupled to the touch display panel and the plurality of touch sensing channels, is used to: Noise detection is performed on multiple touch sensing channels to obtain initial noise information; Obtain the touch-controlled state of each of the aforementioned touch sensing channels; When the touch-sensitive state of each of the touch sensing channels is a pressed state, the noise information corresponding to each of the touch sensing channels is removed, and second noise information is obtained; as well as The first noise information and the second noise information are calculated to obtain noise information without the influence of charging noise, as well as charging noise.

10. The touch display device according to claim 9, characterized in that, The first noise information includes display noise, charging noise, and background noise, and the second noise information includes display noise and background noise.

11. The touch display device according to claim 9, characterized in that, The controller is also used for: During each touch sensing period of the frame cycle, a vertical synchronization signal and a horizontal synchronization signal are applied to the plurality of touch sensing channels; as well as The noise detection action is performed during the noise detection period in each of the aforementioned touch sensing periods.

12. The touch display device according to claim 11, characterized in that, The controller is also used for: Detect display noise of the multiple touch sensing channels corresponding to the current screen; as well as Based on the display noise corresponding to the current screen, determine whether the display data difference between multiple adjacent data lines is greater than a threshold in order to adjust the noise detection period.

13. The touch display device according to claim 12, characterized in that, The controller is also used for: When the difference in the displayed data is greater than the threshold, the start time point of the noise detection period in each of the touch sensing periods is delayed.

14. The touch display device according to claim 13, characterized in that, The delay time length of the starting time point during the noise detection period is equal to the length of multiple pulses of the horizontal synchronization signal.

15. The touch display device according to claim 12, characterized in that, The controller is also used for: When the difference in the displayed data is greater than the threshold, the weight value corresponding to the first noise information obtained during the noise detection is changed.

16. The touch display device according to claim 12, characterized in that, The controller is also used for: During each of the aforementioned touch sensing periods, multiple touch detection actions and noise detection actions are sequentially performed on the plurality of touch sensing channels; as well as When the difference in the displayed data is greater than the threshold, the execution order of the noise detection period in each of the touch sensing periods is changed.

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