Processing circuit of touch screen display and method for determining touch event

Abstract

The present application discloses a processing circuit of a touch screen display and a method for determining a touch event. The method comprises: receiving N first channel data respectively output by N receiving channels when the touch screen display is in a screen-on state, and the N receiving channels are respectively coupled to N sensing channels of the touch screen display; for each receiving channel, subtracting the first channel data corresponding to the receiving channel from the reference data from the receiving channel when the touch screen display is in a screen-off state, and dividing the result of the subtraction between the first channel data and the reference data by a normalization factor to generate normalized data corresponding to the receiving channel, and the normalization factor indicates the degree to which the receiving channel is interfered by display noise; and detecting the touch event according to the N normalized data respectively corresponding to the N receiving channels. The method can improve the accuracy of touch detection in high-noise scenarios.

Description

Technical Field

[0001] The present application relates to touch data processing technology, and more particularly to a method for determining a touch event on a touch screen display, and a processing circuit for the touch screen display. Background Art

[0002] With the development of touch sensing technology, portable electronic products with touch screen displays (such as mobile phones, tablet computers and car systems) have become quite common. However, the trend of thin and light design reduces the distance between the touch screen module and the display screen module, making the touch screen more obviously disturbed by the noise of the display screen, and reducing the accuracy of the touch screen in detecting the touch position. For example, compared with liquid crystal displays (LCDs), organic light emitting diode (OLED) displays do not require a backlight layer and a liquid crystal layer, and have a thinner thickness. Although the use of OLED displays can reduce the thickness of mobile phones, it increases the capacitance between the display screen module and the touch screen module. When the OLED display is in the bright screen state and plays a high-noise picture, the display noise will be coupled to the touch sensor of the touch screen through a capacitor with a high capacitance value, causing a misjudgment of the touch position. Summary of the invention

[0003] One of the purposes of the present application is to disclose a method for determining a touch event on a touch screen display and a processing circuit of the touch screen display to solve the above-mentioned problems in the prior art.

[0004] Certain embodiments of the present application disclose a method for determining a touch event on a touch screen display. The method includes: receiving N first channel data respectively output by N receiving channels included in the touch screen display when the touch screen display is in a screen-on state, N is a positive integer greater than 1, and the N receiving channels are respectively coupled to N sensing channels of the touch screen display; for each of the N receiving channels, subtracting the first channel data corresponding to the receiving channel from the reference data from the receiving channel when the touch screen display is in a screen-off state, and dividing the result of the subtraction between the first channel data and the reference data by a normalization factor to generate normalized data corresponding to the receiving channel, wherein the normalization factor indicates the degree to which the receiving channel is interfered by display noise; and detecting the touch event according to the N normalized data respectively corresponding to the N receiving channels.

[0005] Certain embodiments of the present application disclose a processing circuit for a touch screen display. The processing circuit includes N receiving channels and a controller. The N receiving channels are respectively coupled to N sensing channels of the touch screen display. N is a positive integer greater than 1. Each receiving channel is used to output first channel data according to the sensing result from the corresponding sensing channel when the touch screen display is in a screen-on state. The controller is coupled to the N receiving channels to obtain reference data from the receiving channels when the touch screen display is in a screen-off state, and to execute the above method.

[0006] The touch sensing scheme disclosed in the present application can normalize the channel data of the receiving channels according to the similarities between the display noises coupled to different receiving channels, thereby significantly reducing the interference of the display noise on touch detection and reducing the error rate of touch detection in high-noise scenarios. It can also meet the needs of arbitrarily adjusting the touch refresh rate and maintaining a good signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram of an embodiment of a touch screen display of the present application.

[0008] Figure 2 yes Figure 1 A schematic diagram of an embodiment of a touch screen display is shown.

[0009] Figure 3 is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application.

[0010] Figure 4 is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application.

[0011] Figure 5A FIG. 4 is a schematic diagram of an embodiment of a result of detecting a touch event in a high noise scene.

[0012] Figure 5B yes Figure 2 The touch sensing system shown uses Figure 4 Schematic diagram of the changes in multiple gravity indicators generated by the method shown.

[0013] Figure 6 is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application.

[0014] Figure 7 is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application.

[0015] Figure 8is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application. DETAILED DESCRIPTION

[0016] Provided below are a variety of implementations or examples for implementing the different features of the present application. Specific examples of components and configurations will be described below to simplify the present application. Of course, these descriptions are only examples and are not intended to limit the present application. In addition, the present application may reuse component symbols and / or labels in multiple embodiments. This repetition is for the purpose of brevity and clarity and does not represent the relationship between the different embodiments and / or configurations discussed. Furthermore, it should be understood that if an element is described as "connected to" or "coupled to" another element, the element may be directly connected or coupled to the other element, or indirectly connected or coupled to the other element through other elements.

[0017] The touch sensing system can use the receiving channel to receive the sensing results of the touch event from the touch sensor to detect the touch event. In order to reduce the interference of display noise on touch detection, the connection between the touch sensor and the receiving channel is usually disconnected when the display noise is large, so that the display noise will not enter the receiving channel from the touch sensor.

[0018] For example, a switch may be provided between the touch sensor and the receiving channel, which may be selectively turned on according to a horizontal synchronization signal (Hsync). The horizontal synchronization signal is an indication signal for screen refresh, wherein the magnitude of the display noise is related to the screen refresh rate. When the horizontal synchronization signal has a high signal level, the display noise is relatively large. When the horizontal synchronization signal has a low signal level, the display noise is relatively small. Therefore, the switch may be disconnected when the horizontal synchronization signal has a high signal level, so that the relatively large display noise will not (or almost will not) couple from the touch sensor to the receiving channel. When the horizontal synchronization signal is converted from a high signal level to a low signal level and is at a low signal level for a period of time, the display noise has been reduced a lot. Therefore, the switch may be turned on to connect the receiving channel to the touch sensor, so that the receiving channel can receive the sensing result from the touch sensor.

[0019] However, since the above touch detection method requires the use of a horizontal synchronization signal, the host end needs to output a horizontal synchronization signal to the touch chip, increasing the complexity of the touch sensing system. In addition, limited by the screen refresh rate (or horizontal synchronization signal), the above touch detection method is difficult to meet the demand for arbitrarily adjusting the touch refresh rate. Furthermore, the above touch detection method is not suitable for different screens. For example, for a screen with a long display noise duration, the use of the above touch detection method may cause the receiving channel to be disconnected from the touch sensor for too long, greatly reducing the time for the touch sensor's sensing results to be output to the receiving channel, and reducing the signal-to-noise ratio.

[0020] The touch sensing scheme disclosed in the present application can generate normalized data corresponding to different receiving channels according to the similarity between display noises coupled to different receiving channels at the same time without using a horizontal synchronization signal, wherein the components related to display noise in the normalized data corresponding to each receiving channel are substantially the same. Based on the normalized data corresponding to different receiving channels, the touch event on the touch screen display (touchscreen) is judged. The touch sensing scheme disclosed in the present application can not only improve the accuracy of detecting the touch position in a high noise scene, but also reduce the complexity of the touch sensing system, meet the requirements of arbitrarily adjusting the touch refresh rate, and maintain a good signal-to-noise ratio. Further explanation is as follows.

[0021] Figure 1 1 is a schematic diagram of an embodiment of a touch screen display of the present application. In this embodiment, the touch screen display 100 includes a display screen module 102 and a touch sensing system 104. The touch sensing system 104 is used to detect a touch event TE, such as a contact or non-contact operation performed by a finger or a stylus on the touch screen 102. The touch sensing system 104 can be implemented as (but not limited to) a capacitive touch screen, and can include a touch sensor 110 and a processing circuit 120.

[0022] The touch sensor 110 includes N sensing channels SE1-SE N , where N is a positive integer greater than 1. In an embodiment where the touch sensor 110 adopts a self-capacitance sensing solution, each sensing channel can generate a sensing result (ie, N sensing results SR1-SR N In the embodiment of the touch sensor 110 using a mutual-capacitance sensing scheme, each sensing channel can be connected to a corresponding driving channel ( Figure 1 The mutual capacitance between the sensors (not shown) generates sensing results (i.e., N sensing results SR1-SR NIn addition, since the display screen module 102 may be coupled through N coupling capacitors Cg1-Cg N Couple display noise to N sensing channels SE1-SE N Therefore, the N sensing results SR1-SR N The two pixels may carry display noise from the display module 102 .

[0023] The processing circuit 120 is coupled to the touch sensor 110 and is used to process the touch sensor 110 according to the N sensing results SR1-SR N Detect touch event TE. It is worth noting that the N sensing results SR1-SR generated at the same time (or approximately the same time) N The display noises included in each may have a certain degree of similarity. The processing circuit 120 may process the N sensing results SR1-SR N Generate corresponding N normalized data, wherein the components related to the display noise in the N normalized data are the same (or substantially the same) as each other. By processing the N normalized data, the processing circuit 120 can detect the touch event TE when the influence of the display noise on the detection of the touch event TE is reduced.

[0024] In this embodiment, the processing circuit 120 includes N receiving channels 122.1-122.N and a controller 124. The N receiving channels 122.1-122.N are respectively coupled to the N sensing channels SE1-SE N Each receiving channel is used to output first channel data (ie, N first channel data CH1-CH2) according to the sensing result from the corresponding sensing channel when the touch screen display 100 is in the screen-on state. N The controller 124 is coupled to the N receiving channels 122.1-122.N, and is used to obtain reference data (ie, N reference data CH 122.1-122.N) from the receiving channels when the touch screen display 100 is in the off state. 1B -CH NB One of them), and generate N normalized data corresponding to the N receiving channels 122.1-122.N according to the first channel data and reference data corresponding to each of the N receiving channels 122.1-122.N.

[0025] For example, the controller 124 may subtract the first channel data corresponding to each receiving channel from the reference data, and divide the result of the subtraction between the first channel data and the reference data by a normalization factor to generate normalized data corresponding to the receiving channel, wherein the normalization factor indicates the degree to which the receiving channel is interfered by the display noise. Therefore, the components related to the display noise in the N normalized data corresponding to the N receiving channels 122.1-122.N may be the same (or substantially the same) as each other.

[0026] For ease of understanding, an exemplary circuit structure is used below to illustrate the touch sensing scheme disclosed in the present application. However, this is for illustrative purposes. The touch sensing scheme disclosed in the present application can be applied to a touch sensing scheme based on Figure 1 Other embodiments of the circuit structure shown. Figure 2 , which is Figure 1 The touch screen display 200 includes a touch sensing system 204 and a touch sensing system 206. Figure 1 The touch sensing system 204 includes a touch sensor 210 and a processing circuit 220, which can be used as Figure 1 An embodiment of a touch sensor 110 and a processing circuit 120 is shown.

[0027] The touch sensor 210 includes N sensing channels 212.1-212.N for sensing a touch event TE and generating N sensing results SR1-SR N Taking the sensing channel 212.1 as an example, the sensing channel 212.1 can sense the touch event TE according to the driving signal TX to generate the sensing result SR1, wherein the driving signal TX is generated by the driving circuit ( Figure 2 In this embodiment, the N sensing channels 212.1-212.N can be represented by sensing capacitors and can be coupled to the display module 102 through coupling capacitors. For example, the sensing channel 212.1 can be represented by a sensing capacitor C1, wherein the sensing capacitor C1 can be a self-capacitance or a mutual capacitance corresponding to the sensing channel 212.1, and is coupled to the display module 102 through a coupling capacitor Cg1. It is worth noting that since the display noise from the display module 102 can be coupled to the sensing channel 212.1 through the coupling capacitor Cg1, the sensing result SR1 (such as the charge of the capacitor node N1) can change according to the driving signal TX, the touch event TE and the coupling capacitor Cg1.

[0028] The processing circuit 220 includes N receiving channels 222.1-222.N and a controller 224. The N receiving channels 222.1-222.N can be respectively used as Figure 11-122.N. The N receiving channels 222.1-222.N may have the same (or substantially the same) circuit structure. For example, the driving signal for driving the touch sensor 110 may be a frequency modulated vector signal. Therefore, each receiving channel may output first channel data by performing in-phase and quadrature demodulation (IQ demodulation) on the corresponding sensing result, which may indicate the amplitude and phase information corresponding to the sensing result. In this embodiment, the receiving channel 222.1 includes (but is not limited to) a charge amplifier 232, a low-pass filter 234, an analog-to-digital converter (ADC) 236, an in-phase and quadrature demodulation unit 238, a plurality of digital filters 242.1 and 242.2, and a plurality of downsampling units 244.1 and 244.2.

[0029] The charge amplifier 232 is used to amplify the sensing result SR1 to generate an amplified signal SA. The low-pass filter 234 is used to filter the amplified signal SA to generate a filtered signal SF. The analog-to-digital converter 236 is used to convert the filtered signal SF into a digital signal SD. The in-phase and quadrature demodulation unit 238 is used to perform in-phase and quadrature demodulation on the digital signal SD to generate an in-phase signal SI and a quadrature signal SQ. The digital filter 242.1 is used to filter the in-phase signal SI to generate a filtered signal SFI. The digital filter 242.2 is used to filter the quadrature signal SQ to generate a filtered signal SFQ. The downsampling unit 244.1 is used to downsample the filtered signal SFI to generate in-phase data DI (a part of the first channel data CH1). The downsampling unit 244.2 is used to downsample the filtered signal SFQ to generate quadrature data DQ (another part of the first channel data CH1). The in-phase data DI and the quadrature data DQ may reflect the capacitance value of the sensing capacitor C1 (eg, the self-capacitance or mutual capacitance corresponding to the receiving channel 222 . 1 ).

[0030] The controller 224 is coupled to the N receiving channels 222.1-222.N and is configured to generate N first channel data CH1-CH2 outputted by the N receiving channels 222.1-222.N. N , detect the touch event TE. For example, the controller 224 can detect the capacitance value of the sensing capacitor corresponding to each receiving channel according to the in-phase data and the orthogonal data output by each receiving channel, and judge the touch position of the touch event TE on the touch sensor 210 accordingly. In this embodiment, the N first channel data CH1-CH N and N reference data CH 1B -CHNB Therefore, the controller 224 can be implemented as a digital controller.

[0031] Please include Figure 2 See also Figure 3 . Figure 3 is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application. If the results obtained are substantially the same, the steps do not necessarily have to be followed. Figure 3 For example, Figure 3 The method 300 shown may also include other steps. The touch sensing scheme disclosed in the present application may adopt alternative implementations based on the method 300 without departing from the spirit and scope of the present application. For the purpose of illustration, the following collocation Figure 2 The touch screen display 200 is shown to illustrate Figure 3 The method 300 shown in FIG. However, the present application is not limited thereto. The method 300 is applied to Figure 1 A touch screen display 100 as shown is also possible.

[0032] In step 302, N first channel data respectively outputted by N receiving channels of the touch screen display when the touch screen display is in the bright screen state are received, wherein the N receiving channels are respectively coupled to the N sensing channels of the touch screen display. For example, the controller 224 may receive N first channel data CH1-CH2 respectively outputted by N receiving channels 222.1-222.N when the touch screen display 200 is in the bright screen state. N .

[0033] In step 304, for each of the N receiving channels, first channel data corresponding to the receiving channel is subtracted from reference data from the receiving channel when the touch screen display is in a screen-off state.

[0034] In step 306 , a result of subtracting the first channel data corresponding to the receiving channel from the reference data is divided by a normalization factor to generate normalized data corresponding to the receiving channel, wherein the normalization factor indicates the degree to which the receiving channel is interfered by display noise.

[0035] For example, the display noise coupled from the display module 102 to the touch sensor 210 may be different because different coupling paths have different resistances and different coupling capacitances, so that the display noise coupled to the N sensing channels 212.1-212.N has different amplitudes and phases. However, since the display noise coupled to the N sensing channels 212.1-212.N at the same time (or substantially the same time) is the common mode noise generated by the display module 102 (e.g., from the cathode of the display screen) coupling the touch sensor 210, the display noise coupled to the N sensing channels 212.1-212.N at the same time (or substantially the same time) may have a certain degree of similarity. In other words, the N first channel data CH1-CH2 output by the N receiving channels 222.1-222.N N The components related to display noise may have a certain degree of similarity.

[0036] For example, the first channel data CH output by the receiving channel 222.i i It can be expressed by formula (1):

[0037] CH i =S i +N i +k i ×N c (1)

[0038] , where i is any integer between 1 and N, S i Corresponding to the signal component generated by the sensing channel 212.i in response to the touch event TE, N i is the random noise associated with the receive channel 222.i (eg, noise caused by the circuitry included in the receive channel 222.i). i ×N c Can represent the first channel data CH i The component related to display noise in c is the inherent component of the display noise of the display module 102 coupled to the touch sensor 210, k i k is the ratio coefficient of the display noise of the display screen module 102 coupled to the receiving channel 222.i. i It can be used as a normalization factor to indicate the degree to which the receiving channel 222.i is interfered by the display noise.

[0039] For the receiving channel 222.1, the controller 224 can compare the first channel data CH1 with the reference data CH 1B The result of the subtraction is divided by the normalization factor k1 to generate the normalized data NC1 corresponding to the receiving channel 222.1. 1BWhen the touch screen display 200 is in the off state, the reference data CH 1B There is almost no component related to display noise. In addition, the reference data CH 1B It may be data with a small amount of random noise. For example, the controller 224 may receive a plurality of second channel data {CH 12}, which are outputted by the receiving channel 222.1 at multiple time points when the touch screen display 200 is in the off state. The controller 224 can receive the multiple second channel data {CH 12 The average of} is used as the reference data CH 1B , so that the reference data CH 1B The random noise-related components are greatly reduced or almost non-existent. 1B The data may be data not generated in response to the touch event TE. For example, the controller 224 may obtain the reference data CH from the receiving channel 222.1 before the touch event TE occurs or before the touch event occurs. 1B Therefore, the normalized data NC1 can be expressed by formula (2):

[0040] (CH1-CH 1B ) / k1=ΔS1+(N1 / k1)+N c (2)

[0041] , where ΔS1 may correspond to the signal change amount generated by the sensing channel 212 . 1 due to the touch event TE.

[0042] In addition, based on equation (1), the controller 224 can measure the reference data CH in advance. 1B , and before the touch event TE occurs (or before a touch event occurs) when the touch screen display 200 is in a high noise scene, multiple channel data output by the receiving channel 222.1 are calculated to obtain a normalization factor k1 corresponding to the receiving channel 222.1.

[0043] In step 308, the touch event is detected according to the N normalized data corresponding to the N receiving channels. For example, the controller 224 may detect the touch event according to the N normalized data NC1-NC corresponding to the N receiving channels 222.1-222.N. N , detect touch event TE.

[0044] In this embodiment, the controller 224 may convert the N normalized data NC1-NC N The result of pairwise subtraction removes the components related to display noise (i.e., N c), thereby detecting the touch event TE. For example, the controller 224 may calculate the normalized data NC corresponding to the receiving channel 222.i (i is any integer between 1 and N) i The Mth power of the difference between the K normalized data corresponding to the K receiving channels in the N receiving channels 222.1-222.N is respectively generated to generate K calculation results, where K is a positive integer greater than 1 and M is a positive real number. In addition, the controller 224 can generate a channel index of the receiving channel 222.i according to the K calculation results, such as the N channel indexes idx1-idx corresponding to the N receiving channels 222.1-222.N respectively. N Next, the controller 224 may determine whether the touch event TE occurs on the sensing channel 212 . i coupled to the receiving channel 222 . i according to the channel indicator.

[0045] It is worth noting that the components related to display noise in each normalized data are the inherent components of the display noise coupled to the corresponding receiving channel. N By performing relevant processing, the controller 224 can generate a processing result that removes components related to display noise, so as to accurately detect the location where the touch event TE occurs while greatly reducing the interference of the display noise. In addition, according to the detection result of the touch event TE, the controller 224 can further control the operation of the touch display 200.

[0046] For ease of understanding, the following is given Figure 2 The controller 224 shown in FIG. 24 is based on the N normalized data NC1-NC N Different implementations of calculating channel indicators to detect touch events TE. However, the present application is not limited to this. As long as the touch sensing scheme can normalize multiple channel data to reduce components related to display noise to detect touch events, the relevant alternative implementations still belong to the spirit and scope of the present application.

[0047] Figure 4 400 is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application. Figure 3 For the purpose of illustration, the following method 300 is used. Figure 2 The touch screen display 200 is shown to illustrate Figure 4 The method 400 shown in FIG. However, the present application is not limited thereto. The method 400 is applied to Figure 1 A touch screen display 100 as shown is also possible.

[0048] First, in step 402, the touch sensing system 204 can measure N first channel data CH1-CH2 respectively outputted by the N receiving channels 222.1-222.N at a certain moment. N Step 402 can be used as Figure 3 For example, when the touch screen display 200 is in the screen-on state, the N receiving channels 222.1-222.N can receive the N sensing results SR1-SR2 at the same time (or approximately the same time). N , based on which N first channel data CH1-CH N The controller 224 may receive N first channel data CH1-CH2 from the N receiving channels 222.1-222.N at the same time (or substantially the same time). N .

[0049] In step 404, the controller 224 may calculate the normalized data corresponding to each receiving channel. Step 404 may be performed as Figure 3 For example, the controller 224 may calculate the normalized data of each receiving channel using the above equation (2). Figure 2 In the embodiment shown, the channel data output by each receiving channel is vector data including in-phase data and quadrature data. Therefore, the normalized data of the N receiving channels 222.1-222.N can be represented as the vector NC shown below: V .

[0050] NC V =[NC1,NC2,…,NC N ]

[0051] =[(CH1-CH 1B ) / k1,(CH2-CH 2B ) / k2,…,(CH N -CH NB ) / k N ] (3)

[0053] In step 406, the controller 224 may generate a vector NC V Calculate the gravity index corresponding to each receiving channel. Taking receiving channel 222.i (i is any integer between 1 and N) as an example, the gravity index G of receiving channel 222.i i It can be expressed as:

[0054]

[0055] , where n0 and n1 are positive integers less than N, n0 is less than n1, M is a positive real number, and r0 is a non-zero real number. That is, the controller 224 can calculate the normalized data NC corresponding to the receiving channel 222.i i The Mth power of the difference between the K normalized data corresponding to the K receiving channels in the N receiving channels 222.1-222.N is used to generate K calculation results (ie, |NC i -NC n0 | M 、…、|NC i -NC n1 | M ), where K = (n1-n0+1). In addition, the controller 224 may add the K calculation results to the predetermined value |r0| to generate K addition results, and add the reciprocals of the K addition results to generate the gravity index G i , which can be used as Figure 2 The channel indicator idx is shown i implementation method.

[0056] In step 408, the controller 224 may i Determine whether the touch event TE occurs on the sensing channel 212.i. Step 406 and step 408 can be used as Figure 3 For example, when the number of sensing channels touched at the same time is less than a predetermined number, when the gravity indicator G i When the gravity index G is less than the threshold, the controller 224 can determine that the touch event TE occurs on the sensing channel 212.i. i When the value is greater than or equal to the threshold, the controller 224 may determine that the touch event TE does not occur on the sensing channel 212.i. The predetermined number may be (but is not limited to) one fourth or one half of the number of sensing channels of the touch sensor 210.

[0057] The above details of method 400 are for illustrative purposes and are not intended to limit the scope of the present application. For example, the above predetermined value |r0| may be replaced by other suitable negative real numbers. For another example, when the number of sensing channels touched at the same time is greater than the predetermined number, the controller 224 may adjust the gravity indicator G i When it is greater than the threshold, it is determined that the touch event TE occurs on the sensing channel 212.i. For another example, n1 can be set to the number of receiving channels (ie, N) of the processing circuit 220.

[0058] Figure 5A and Figure 5B They represent the results of detecting touch events in high noise scenarios. Figure 2 See also Figure 5A, which is directly adopted Figure 2 The channel data CH shown i and Figure 2 Reference data shown in CH iB The gap between Figure 2 Schematic diagram showing whether the sensing channel 212.i has an indicator of being touched. For the purpose of illustration, in this embodiment, N is equal to 29, and the touch event TE occurs on multiple sensing channels 212.7-212.9. Figure 5A As shown, since the display noise of the display screen module 102 coupled to the touch sensor 210 is relatively large, the component related to the display noise in the first channel data output by the receiving channel is much larger than the signal component generated by the corresponding sensing channel in response to the touch event TE. i -CH iB |Whether it is greater than the threshold value determines the location where the touch event TE occurs.

[0059] Please include Figure 2 See also Figure 5B , which is Figure 2 The touch sensing system 204 shown uses Figure 4 The method 400 shown generates N gravity indicators G1-G N For the purpose of illustration, in this embodiment, N is equal to 29, and the touch event TE occurs on multiple sensing channels 212.7-212.9. Figure 5B As shown, the gravity indexes G7-G9 corresponding to the plurality of sensing channels 212.7-212.9 are significantly lower than the gravity indexes corresponding to other sensing channels. In other words, the controller 224 can perform normalization processing on the channel data to significantly reduce the interference of display noise, thereby accurately determining the location where the touch event TE occurs.

[0060] In some embodiments, multiple normalized data may be divided into multiple groups of normalized data to divide the corresponding multiple sensing channels into multiple groups of sensing channels, so that touch detection is performed on each group of sensing channels respectively. By grouping multiple normalized data for touch detection, the touch sensing scheme disclosed in the present application can shorten the time required for touch detection. Figure 2 See also Figure 6 , which is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application. Method 600 can be used as Figure 3 An embodiment of the method 300 shown in FIG. Figure 4 The method 400 shown in FIG. 4 is substantially the same, and the difference between the two is that the method 600 may be N normalized data NC1-NC N The data are divided into multiple groups of normalized data, and touch events TE are detected accordingly.

[0061] In this embodiment, the method 600 may be performed by Figure 4 In step 402 and step 404, the normalized data corresponding to each receiving channel is calculated. Next, in step 605, the controller 224 can calculate the N normalized data NC1-NC N Divided into P groups GP1-GP P , to respectively group P GP1-GP P For touch detection, where P is a positive integer. For example, in step 606.1, the controller 224 may use the operation of step 406 to calculate the gravity index corresponding to each receiving channel in group GP1. That is, the controller 224 may calculate the gravity index of the receiving channel based on the normalized data corresponding to a receiving channel in group GP1 and the multiple normalized data corresponding to multiple receiving channels in group GP1. Similarly, in step 606.q (q is any integer between 2 and P), the controller 224 may use the operation of step 406 to calculate the gravity index of group GP1. q The gravity index corresponding to each receiving channel in .

[0062] In step 608.1, the controller 224 may use the operation of step 408 to determine whether the touch event TE occurs on the sensing channel corresponding to group GP1. Similarly, in step 608.q (q is any integer between 2 and P), the controller 224 may use the operation of step 408 to determine whether the touch event TE occurs on the sensing channel corresponding to group GP q On the corresponding sensing channel.

[0063] In some embodiments, other methods may be used to generate the channel index idx corresponding to the receiving channel 222.i according to the above K calculation results. i Please include Figure 2 See also Figure 7 , which is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application. Method 700 can be used as Figure 3 An embodiment of the method 300 shown in FIG. Figure 4 The method 400 shown is substantially the same, the difference between the two being the implementation method for generating the channel indicator.

[0064] In this embodiment, the method 700 may be performed by Figure 4 Steps 402 and 404 shown in the figure calculate the normalized data corresponding to each receiving channel, such as the vector NC shown in the above formula (3) V Next, in step 706, the controller 224 may calculate the N normalized data NC1-NC NCalculate the anti-gravity index corresponding to each receiving channel. Taking receiving channel 222.i (i is any integer between 1 and N) as an example, the anti-gravity index IG of receiving channel 222.i i It can be expressed as:

[0065]

[0066] , where n0 and n1 are positive integers less than N, n0 is less than n1, and M is a positive real number. That is, the controller 224 can calculate the normalized data NC corresponding to the receiving channel 222.i i The Mth power of the difference between the K normalized data corresponding to the K receiving channels in the N receiving channels 222.1-222.N is used to generate K calculation results (ie, |NC i -NC n0 | M 、…、|NC i -NC n1 | M ), where K = (n1-n0+1). In addition, the controller 224 may add the K calculation results to generate the anti-gravity index IG i , which can be used as Figure 2 The channel indicator idx is shown i implementation method.

[0067] In step 708, the controller 224 may determine the anti-gravity index IG i Determine whether the touch event TE occurs on the sensing channel 212.i coupled to the receiving channel 222.i. Step 706 and step 708 can be used as Figure 3 For example, when the number of sensing channels touched at the same time is less than a predetermined number, when the anti-gravity indicator IG i When the anti-gravity indicator IG i When the touch event TE is less than or equal to the threshold, the controller 224 may determine that the touch event TE does not occur on the sensing channel 212.i. The predetermined number may be (but is not limited to) one quarter or one half of the number of sensing channels of the touch sensor 210.

[0068] The above details of method 700 are for illustrative purposes and are not intended to limit the scope of the present application. For example, when the number of sensing channels touched at the same time is greater than a predetermined number, the controller 224 may iWhen the touch event TE is less than the threshold, it is determined that the touch event TE occurs on the sensing channel 212.i. For another example, n1 can be set to the number of receiving channels (ie, N) of the processing circuit 220. For another example, the control 224 can set the N normalized data NC1-NC N The data is divided into multiple groups of normalized data, and the operations of step 706 and step 708 are used to perform touch detection on each group of normalized data.

[0069] Please include Figure 2 See also Figure 8 , which is a flow chart of an embodiment of a method for detecting a touch event on a touch screen display of the present application. Method 800 can be used as Figure 3 An embodiment of the method 300 shown in FIG. Figure 4 The method 400 shown is substantially the same, the difference between the two being the implementation method for generating the channel indicator.

[0070] In this embodiment, the method 800 may be performed by Figure 4 Steps 402 and 404 shown in the figure calculate the normalized data corresponding to each receiving channel, such as the vector NC shown in the above formula (3) V Next, in step 806, the controller 224 may calculate the N normalized data NC1-NC N Calculate the group index GN corresponding to the receiving channel 222.i (i is any integer between 1 and N) i , which can be used as Figure 2 The channel indicator idx is shown i implementation method.

[0071] For example, the controller 224 may calculate the normalized data NC corresponding to the receiving channel 222.i i The Mth power of the difference between the K normalized data corresponding to the K receiving channels in the N receiving channels 222.1-222.N is used to generate K calculation results (ie, |NC i -NC n0 | M 、…、|NC i -NC n1 | M ), where K = (n1-n0+1). In addition, the controller 224 may calculate the number of calculation results that are less than the reference value TH among the K calculation results to generate a group index GN i . Group indicator GN i It can be expressed as:

[0072]

[0073] , where n0 and n1 are positive integers less than N, and n0 is less than n1. NB(i,j) can be determined by formula (7):

[0074]

[0075] , that is, when |NC i -NC n0 | M When NB(i,j) is greater than or equal to the reference value TH, NB(i,j) is equal to 0; when |NC i -NC n0 | M When NB(i,j) is less than the reference value TH, NB(i,j) is equal to 1. Therefore, the group index GN i It can indicate the normalized data NC of the receiving channel 222.i i The degree of similarity to the normalized data corresponding to other received channels.

[0076] In step 808, the controller 224 may generate a group index GN i It is determined whether the touch event TE occurs on the sensing channel 212.i coupled to the receiving channel 222.i. For example, when the number of sensing channels touched at the same time is less than a predetermined number, when the group indicator GN i When the touch event TE is greater than the threshold, the controller 224 may determine that the touch event TE does not occur on the sensing channel 212.i. The predetermined number may be (but is not limited to) one fourth or one half of the number of sensing channels of the touch sensor 210.

[0077] In step 810, when it is determined that the touch event TE does not occur in the sensing channel 212.i, the controller 224 may determine that the touch event TE does not occur in the sensing channel 212.j corresponding to when NB(i,j) is equal to 1. In addition, the controller 224 may define the receiving channels involved when NB(i,j) is equal to 1 as the channel set GX i . To calculate the group index GN of the receiving channel 222.1 i For example, when NB(1,2), NB(1,3) and NB(1,4) are all equal to 1, the controller 224.1 can determine that the touch event does not occur on the multiple sensing channels 212.1-212.4, and define a channel set GX1, which includes the multiple sensing channels 212.1-212.4.

[0078] In step 812, the controller 224 may determine whether all the N receiving channels 222.1-222.N have completed the detection. If so, step 814 is executed; otherwise, step 806 is executed. For example, the controller 224 may determine whether all the N receiving channels 222.1-222.N have completed the detection by determining whether the group indicators of the N receiving channels 222.1-222.N have been calculated.

[0079] In step 814, the controller 224 may determine the location where the trigger event TE occurs based on the union of the channel sets corresponding to the N receiving channels 222.1-222.N. For example, the above union may indicate a set of sensing channels that are not touched, and the controller 224 may determine the sensing channels outside the set of sensing channels as the location where the touch event TE occurs. Steps 806 to 814 may be used to implement Figure 3 Step 308 is shown.

[0080] The above details about method 800 are for illustrative purposes and are not intended to limit the scope of the present application. For example, n1 can be set to the number of receiving channels (i.e., N) possessed by the processing circuit 220. For another example, the controller 224 can omit the execution of steps 812 and 814, and determine the location where the touch event TE occurs based on the channel set corresponding to a certain receiving channel. For another example, the controller 224 can omit the execution of steps 810 and 814, and determine whether the corresponding sensing channel is touched based on the group indicators of the N receiving channels 222.1-222.N.

[0081] Please refer again Figure 1 In this embodiment, the controller 124 may include (but not limited to) a memory 126 and a processor 128. The memory 126 may be used to store program instructions. The processor 128 is coupled to the memory 126 and may be used to call the program instructions stored in the memory 126 so that the controller 124 executes the touch sensing scheme disclosed in the present application, for example Figure 3 The method 300 shown, Figure 4 The method 400 shown, Figure 6 The method 600 shown, Figure 7 The method 700 and Figure 8 At least one of the methods 800 shown in FIG. 8A and 8B. Similarly, in some embodiments, Figure 2 The controller 224 shown may include a memory and a processor (not shown), wherein the processor may call program instructions stored in the memory so that the controller 224 executes the touch sensing scheme disclosed in the present application. Figures 1 to 8After the above description, it should be understood that the operation details of the controller 124 / 224 including the memory and the processor to execute the touch sensing scheme disclosed in the present application can be understood, so further description is not repeated here.

[0082] The touch sensing scheme disclosed in the present application can normalize the channel data of the receiving channels according to the similarities between the display noises coupled to different receiving channels, thereby significantly reducing the interference of the display noise on touch detection and reducing the error rate of touch detection in high-noise scenarios. It can also meet the needs of arbitrarily adjusting the touch refresh rate and maintaining a good signal-to-noise ratio.

[0083] The above description briefly presents the features of certain embodiments of the present application, so that those skilled in the art can more fully understand the multiple aspects of the present application. Those skilled in the art should understand that they can easily use the present application as a basis to design or change other processes and structures to achieve the same purpose and / or achieve the same advantages as the embodiments described above. Those skilled in the art should understand that these equivalent embodiments still belong to the spirit and scope of the present application, and they can be variously changed, substituted and modified without departing from the spirit and scope of the present application.

Claims

1. A method for detecting a touch event on a touch screen display, characterized in that: include: Receiving N first channel data respectively output by N receiving channels of the touch screen display when the touch screen display is in a bright screen state, wherein N is a positive integer greater than 1, and the N receiving channels are respectively coupled to the N sensing channels of the touch screen display; For each of the N receiving channels: Subtracting the first channel data output by the receiving channel from the reference data from the same receiving channel when the touch screen display is in a screen-off state; as well as Dividing a result of subtracting the first channel data from the same receiving channel from the reference data by a normalization factor to generate normalized data corresponding to the receiving channel, wherein the normalization factor indicates the degree to which the receiving channel is interfered by display noise; as well as The touch event is detected according to the N normalized data respectively corresponding to the N receiving channels.

2. The method according to claim 1, characterized in that Also includes: Before the touch event occurs, the reference data from the receiving channel is obtained when the touch screen display is in a screen-off state.

3. The method according to claim 1, characterized in that The step of detecting the touch event according to the N normalized data corresponding to the N receiving channels respectively comprises: calculating the Mth power of the difference between the normalized data corresponding to the receiving channel and K normalized data corresponding to K receiving channels among the N receiving channels respectively, to generate K calculation results, wherein K is a positive integer greater than 1, and M is a positive real number; Generating a channel index of the receiving channel according to the K calculation results; and According to the channel indicator, it is determined whether the touch event occurs on the sensing channel coupled to the receiving channel.

4. The method according to claim 3, characterized in that The step of generating the channel index according to the K calculation results comprises: Adding predetermined values ​​to the K calculation results respectively to generate K addition results; and The reciprocals of the K addition results are added together to generate the channel index.

5. The method according to claim 4, characterized in that The predetermined value is a positive real number.

6. The method according to claim 4, characterized in that The step of judging whether the touch event occurs on the sensing channel according to the channel indicator comprises: When the channel index is less than a threshold, determining that the touch event occurs on the sensing channel; and When the channel index is greater than or equal to the threshold, it is determined that the touch event does not occur on the sensing channel.

7. The method according to claim 3, characterized in that The step of generating the channel index according to the K calculation results comprises: The K calculation results are added together to generate the channel index.

8. The method according to claim 7, characterized in that The step of judging whether the touch event occurs on the sensing channel according to the channel indicator comprises: When the channel index is greater than a threshold, determining that the touch event occurs on the sensing channel; and When the channel index is less than or equal to the threshold, it is determined that the touch event does not occur on the sensing channel.

9. The method according to claim 3, characterized in that The step of generating the channel index according to the K calculation results comprises: The number of calculation results that are smaller than a reference value among the K calculation results is calculated to generate the channel index.

10. The method according to claim 9, characterized in that The step of judging whether the touch event occurs on the sensing channel according to the channel indicator comprises: When the channel index is greater than a threshold, it is determined that the touch event does not occur on the sensing channel.

11. The method according to claim 10, characterized in that One of the K calculation results that is smaller than the reference value comes from normalized data corresponding to the receiving channel and normalized data corresponding to another receiving channel different from the receiving channel; The step of detecting the touch event according to the N normalized data respectively corresponding to the N receiving channels further includes: When it is determined that the touch event does not occur in the sensing channel, it is determined that the touch event does not occur in the sensing channel coupled to the other receiving channel.

12. The method according to any one of claims 3 to 11, characterized in that The step of detecting the touch event according to the N normalized data respectively corresponding to the N receiving channels further includes: The N normalized data are divided into P groups, wherein the normalized data and the K normalized data are located in the same group among the P groups.

13. The method according to any one of claims 1 to 11, characterized in that The N first channel data are received at the same time when the touch screen display is in the screen-on state.

14. The method according to any one of claims 1 to 11, characterized in that The step of obtaining the reference data from the receiving channel when the touch screen display is in the screen-off state comprises: receiving a plurality of second channel data respectively outputted by the receiving channel at a plurality of time points when the touch screen display is in the screen-off state; and An average of the plurality of second channel data is used as the reference data.

15. A processing circuit for a touch screen display, characterized in that: include: N receiving channels, respectively coupled to the N sensing channels of the touch screen display, where N is a positive integer greater than 1; Each receiving channel is used to output first channel data according to the sensing result from the corresponding sensing channel when the touch screen display is in a bright screen state; as well as A controller is coupled to the N receiving channels, and is used to obtain reference data from the receiving channels when the touch screen display is in a screen-off state, and to execute the method described in any one of claims 1 to 14 above.

16. The processing circuit according to claim 15, characterized in that The controller includes: a memory for storing program instructions; and A processor, coupled to the memory, is used to call program instructions stored in the memory so that the controller executes the method described in any one of claims 1 to 14.

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