A multi-chip cascaded touch screen scanning synchronization device, method and touch screen structure

Abstract

The present invention discloses a multi-chip cascaded touch screen scanning synchronization device, method and touch screen structure. The multi-chip cascaded touch screen scanning synchronization device includes a plurality of touch control chips and a central control unit. Every two touch control chips cooperate to control a selected sub-touch screen area, and both ends of each TX channel in the sub-touch screen area are simultaneously excited by two touch control chips to achieve synchronization of scanning waveforms. The central control unit is used to receive scanning data from the touch control chips and execute tasks according to the scanning data. The present invention can greatly expand the area of the touch screen, thereby achieving efficient scanning and synchronization of the touch screen, and the scanning time only needs to increase the scanning time of one driving channel.

Description

Technical Field

[0001] The present invention relates to the technical fields of touch screen technology and multi-chip cascading technology, and particularly to a multi-chip cascading touch screen scanning synchronization device, method and touch screen structure. Background Art

[0002] In recent years, large-size touch screens have been increasingly widely used in fields such as commerce, information service terminals, interactive entertainment, and smart homes. However, as the area of the touch screen increases, the demand for hardware resources such as the storage space, channel number, and processing speed of the touch control chip also increases accordingly. Increasing the hardware resources of the touch control chip not only leads to an increase in the chip area and a decrease in the yield rate, but also brings the problem of an increase in the scanning time, thereby affecting the response speed and overall performance of the touch screen.

[0003] Although a single high-performance touch control chip can meet the requirements of a large-size touch screen, its high cost and complex manufacturing process limit its large-scale application. In addition, single-chip sequential scanning or multi-chip cascading sequential scanning are both prone to performance bottlenecks when processing large-area touch screens, resulting in an extended response time and affecting the user experience. Therefore, how to reduce the cost of the touch screen module through optimized design while ensuring the performance of the touch screen has become an urgent problem to be solved. Summary of the Invention

[0004] The object of the present invention is to provide a multi-chip cascading touch screen scanning synchronization device, method and touch screen structure, which can achieve a large-scale expansion of the touch screen area, thereby achieving efficient scanning and synchronization of the touch screen, and the scanning time only needs to increase the scanning time of one driving channel.

[0005] To solve the above technical problems, the present invention provides a multi-chip cascading touch screen scanning synchronization device, including: a plurality of touch control chips and a central control unit;

[0006] Every two of the touch control chips cooperate to control a selected sub-touch screen area, and both ends of each TX channel in the sub-touch screen area are simultaneously excited by the two touch control chips;

[0007] The central control unit is configured to receive scanning data from the touch control chips and execute tasks according to the scanning data.

[0008] Further, the touch control chip includes a TXBUS bus and an RXBUS bus; the TXBUS bus is used to drive the TX electrodes connected to the TX channels; the RXBUS bus is used to sense the RX electrodes connected to the RX channels.

[0009] Further, the plurality of touch control chips include a first touch control chip, a second touch control chip, a third touch control chip, and a fourth touch control chip;

[0010] The TXBUS bus of the first touch chip is used to connect one end of the TX channel in the first sub-touch screen area, and the RXBUS bus of the first touch chip is used to connect part of the RX channels in the first sub-touch screen area;

[0011] The TXBUS bus of the second touch chip is used to connect the other end of the TX channel in the first sub-touch screen area, and the RXBUS bus of the second touch chip is used to connect the remaining RX channels in the first sub-touch screen area;

[0012] The TXBUS bus of the third touch chip is used to connect one end of the TX channel in the second sub-touch screen area, and the RXBUS bus of the third touch chip is used to connect part of the RX channels in the second sub-touch screen area;

[0013] The TXBUS bus of the fourth touch chip is used to connect the other end of the TX channel in the second sub-touch screen area, and the RXBUS bus of the fourth touch chip is used to connect the remaining RX channels in the second sub-touch screen area;

[0014] The first touch chip and the second touch chip are synchronized via a first synchronization bus; the third touch chip and the fourth touch chip are synchronized via a second synchronization bus; and the first touch chip and the third touch chip are synchronized via a third synchronization bus.

[0015] Furthermore, both the first synchronization bus and the second synchronization bus include a plurality of first GPIO pins, a portion of which are used for nanosecond level scanning phase synchronization, and another portion of which are used for microsecond level workflow synchronization.

[0016] Furthermore, the third synchronous bus includes a plurality of second GPIO pins for time-sharing scanning of TX channels adjacent to the first sub-touch screen area and the second sub-touch screen area.

[0017] Furthermore, the first touch control chip, the second touch control chip, the third touch control chip and the fourth touch control chip are all connected to the central control unit via a REPORTBUS bus.

[0018] Furthermore, the task includes at least one of coordinate calculation, finger ID tracking and gesture recognition.

[0019] In addition, the present invention also provides a touch screen structure, which includes the multi-chip cascaded touch screen scanning synchronization device as described above, and further includes a plurality of TX channels and a plurality of RX channels; the TX channels and the RX channels are arranged in an interleaved manner to form a touch screen area; the touch screen area is divided into a plurality of independent sub-touch screen areas by physical disconnection or non-physical contact; both ends of each TX channel in the sub-touch screen area are simultaneously excited by two touch control chips respectively.

[0020] Further, a dividing line is provided on the touch screen area, and according to the dividing line, the touch screen area is divided into a first sub-touch screen area and a second sub-touch screen area; the plurality of touch control chips include a first touch control chip, a second touch control chip, a third touch control chip, and a fourth touch control chip;

[0021] Both ends of the TX channels located in the first area are respectively connected to the relatively arranged first touch control chip and the second touch control chip; one end of some of the RX channels located in the first area is connected to the first touch control chip, and one end of some of the RX channels located in the first area is connected to the second touch control chip; one end of some of the RX channels located in the second area is connected to the third touch control chip, and one end of some of the RX channels located in the second area is connected to the fourth touch control chip.

[0022] Further, there is a predetermined distance between the first sub-touch screen area and the second sub-touch screen area, and the range of the predetermined distance is between 10μm - 50μm.

[0023] In addition, the present invention also provides a multi-chip cascaded touch screen scanning synchronization method, which uses the multi-chip cascaded touch screen scanning synchronization device as described above, or uses the touch screen structure as described above, and specifically includes the following:

[0024] Disconnect the touch screen structure to form a plurality of sub-touch screen areas, and every two touch control chips cooperate to control a selected sub-touch screen area to achieve the synchronization of scanning waveforms and the time-sharing scanning strategy, and obtain scanning data;

[0025] The central control unit coordinates the work of the touch control chips according to the scanning data.

[0026] Further, the step of disconnecting the touch screen structure to form a plurality of sub-touch screen areas, and every two touch control chips cooperate to control a selected sub-touch screen area to achieve the synchronization of scanning waveforms and the time-sharing scanning strategy specifically includes:

[0027] Disconnect the touch screen structure to form a first sub-touch screen area and a second sub-touch screen area; both ends of each TX channel in each of the sub-touch screen areas are simultaneously excited by two of the touch control chips; perform time-division scanning on the TX channels at the junction of the first sub-touch screen area and the second sub-touch screen area.

[0028] Further, the performing time-division scanning on the TX channels at the junction of the first sub-touch screen area and the second sub-touch screen area specifically includes: the terminal TX channels adjacent to the second sub-touch screen area in the first sub-touch screen area are scanned within a time period T1, and the head TX channels adjacent to the first sub-touch screen area in the second sub-touch screen area are scanned within a time period T2.

[0029] Further, when the terminal TX channels in the first sub-touch screen area need to achieve synchronization of the scanning waveforms, after the first touch control chip is started, the terminal TX channels are configured and then enter a waiting state, waiting for the second touch control chip to be started; after the second touch control chip is started, the terminal TX channels are configured and the first touch control chip is notified to prepare for synchronization through a first synchronization bus; after receiving the synchronization signal, the first touch control chip triggers the scanning of the terminal TX channels, and at the same time, also achieves nanosecond-level scanning synchronization with the second touch control chip through the first synchronization bus.

[0030] Further, when the head TX channels in the second sub-touch screen area need to achieve synchronization of the scanning waveforms, the first touch control chip notifies a third touch control chip to prepare for synchronization of the head TX channels through a third synchronization bus; the third touch control chip configures the head TX channels and then enters a waiting state, waiting for the fourth touch control chip to be started; after the fourth touch control chip is started, the head TX channels are configured and the third touch control chip is notified to prepare for synchronization through a second synchronization bus; after receiving the synchronization signal, the third touch control chip waits for the first touch control chip to complete the scanning notification of the terminal TX channels, and after receiving the scanning notification, the third touch control chip triggers the scanning of the head TX channels, and at the same time, also achieves nanosecond-level scanning synchronization with the fourth touch control chip through the second synchronization bus.

[0031] Further, when the remaining TX channels in the first sub-touch screen area and the second sub-touch screen area need to achieve synchronization of the scanning waveforms, after the scanning of the terminal TX channels in the first sub-touch screen area is completed, the first touch control chip synchronizes with the second touch control chip through the first synchronization bus to scan the remaining TX channels in the first sub-touch screen area; wherein, after each scanning is completed, the second touch control chip notifies the first touch control chip to prepare for the scanning of the next TX channel through the first synchronization bus;

[0032] After the scanning of the first-end TX channels in the second sub-touch screen area is completed, the third touch control chip synchronizes with the fourth touch control chip to scan the remaining TX channels in the second sub-touch screen area through the second synchronization bus; wherein, after each scanning is completed, the fourth touch control chip notifies the third touch control chip to prepare for the scanning of the next TX channel through the second synchronization bus.

[0033] Further, the central control unit coordinates the work of the touch control chips according to the scanning data, specifically including: the central control unit receives the scanning data reported by the touch control chips and performs task processing; if there is a touch control chip that has not reported the scanning data, the central control unit will reset and restart all the touch control chips in sequence, that is, perform an initialization operation.

[0034] Through the above technical solution, the present invention has the following beneficial effects:

[0035] In this embodiment, by jointly controlling a selected sub-touch screen area by every two touch control chips, and both ends of each TX channel in the sub-touch screen area are simultaneously excited by two touch control chips to achieve the synchronization of the scanning waveforms; the central control unit is used to receive the scanning data from the touch control chips and execute tasks according to the scanning data. It can achieve a large expansion of the touch screen area, thereby achieving efficient scanning and synchronization of the touch screen, and the scanning time only needs to increase the scanning time of one driving channel (i.e., the TX channel).

[0036] In addition, the present invention divides the touch screen structure into multiple independent parts, namely sub-touch screen areas, through physical disconnection or non-physical contact design, and each part is controlled by a separate touch control chip, realizing the synchronization of the scanning waveforms and the improvement of the overall scanning efficiency.

[0037] In addition, for the TX channels at the junction of the upper and lower parts, that is, the first sub-touch screen area and the second sub-touch screen area, the present invention adopts a time-sharing scanning strategy to effectively avoid signal interference and ensure the accuracy and stability of the scanning.

[0038] Therefore, the present invention can expand the area of the touch screen by several times, such as four times, and compared with the traditional single large-channel chip or multi-chip cascade sequential scanning method, the overall scanning time is significantly shortened. It reserves sufficient time resources for the execution of subsequent communication processing, coordinate calculation of the central control unit, finger ID tracking, gesture recognition and other advanced algorithms; making the present invention have a wide range of application prospects in the fields of large touch screens, multi-zone touch screens and electronic devices that require high-precision touch operations. Description of the Drawings

[0039] Figure 1 It is a schematic diagram of the overall structure of a touch screen managed by a touch control chip in the prior art;

[0040] Figure 2 This is a schematic diagram of the overall structure of a multi-chip cascaded touch screen scanning synchronization device in an embodiment of the present invention;

[0041] Figure 3 This is a flowchart of a multi-chip cascaded touch screen scanning synchronization method in an embodiment of the present invention. Detailed implementation manners

[0042] The following will describe in more detail a multi-chip cascaded touch screen scanning synchronization device, method and touch screen structure of the present invention with reference to the accompanying drawings, in which the preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation to the present invention.

[0043] In the following paragraphs, the present invention will be described more specifically by way of example with reference to the accompanying drawings. The advantages and features of the present invention will be clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0044] Taking the diamond-shaped bridging electrode as an example, Figure 1 and Figure 2 The dotted parts in are TX electrodes or RX electrodes that are omitted and not shown. Among them, each TX channel is responsible for driving one or more TX electrodes, and each RX channel is usually connected to one RX electrode. Figure 1 shows the structure of a 27.5-inch touch screen that can be managed by a single touch chip. Figure 2 shows the structure of a 55-inch touch screen realized by cascading 4 touch chips. Although the screen area in this embodiment is increased by 4 times, the scanning time only increases by the scanning time of one TX relative to the 27.5-inch touch screen. Among them, the increased scanning time of one TX is caused by the time-division scanning of the two TXs at the ends and the beginnings of the upper and lower regions (i.e., the first sub-touch screen region and the second sub-touch screen region).

[0045] As Figure 2 shown, an embodiment of the present invention provides a multi-chip cascaded touch screen scanning synchronization device, including: a plurality of touch chips and a central control unit.

[0046] More specifically, every two of the touch chips cooperate to control a selected sub-touch screen region, and both ends of each TX channel in the sub-touch screen region are simultaneously excited by the two touch chips to achieve synchronization of the scanning waveforms, that is, the synchronous excitation technology. As the electrodes grow, the impedance increases, thereby enhancing the driving ability and avoiding interference.

[0047] The central control unit is configured to receive the scan data from the touch chip and execute tasks according to the scan data.

[0048] Among them, the central control unit (MCU) can adopt a product with the model number GD32F407. The touch chip can be various touch chips with the scan phase synchronization function.

[0049] In this embodiment, the central control unit coordinates the scan timings of the touch chips through the main touch chip to ensure the synchronization and interference-free of the scan process.

[0050] In this embodiment, the touch chip includes a TXBUS bus and an RXBUS bus; the TXBUS bus is used to drive the TX electrodes connected to the TX channels; the RXBUS bus is used to sense (or detect) the RX electrodes connected to the RX channels.

[0051] Taking four touch chips and two sub-touch screen areas as an example, continue to refer to Figure 2 As shown, the multiple touch chips include a first touch chip TC1, a second touch chip TC2, a third touch chip TC3, and a fourth touch chip TC4.

[0052] Specifically, the TXBUS bus of the first touch chip TC1 is used to connect one end of the TX channels in the first sub-touch screen area, and the RXBUS bus of the first touch chip TC1 is used to connect some of the RX channels in the first sub-touch screen area; the TXBUS bus of the second touch chip TC2 is used to connect the other end of the TX channels in the first sub-touch screen area, and the RXBUS bus of the second touch chip TC2 is used to connect the remaining RX channels in the first sub-touch screen area; the TXBUS bus of the third touch chip TC3 is used to connect one end of the TX channels in the second sub-touch screen area, and the RXBUS bus of the third touch chip TC3 is used to connect some of the RX channels in the second sub-touch screen area; the TXBUS bus of the fourth touch chip TC4 is used to connect the other end of the TX channels in the second sub-touch screen area, and the RXBUS bus of the fourth touch chip TC4 is used to connect the remaining RX channels in the second sub-touch screen area.

[0053] Among them, the first touch chip TC1 and the second touch chip TC2 are synchronized through the first synchronization bus SYNCBUS12; the third touch chip TC3 and the fourth touch chip TC4 are synchronized through the second synchronization bus SYNCBUS34; the first touch chip TC1 and the third touch chip TC3 are synchronized through the third synchronization bus SYNCBUS13.

[0054] In this embodiment, multiple touch chips can coordinate their own and other touch chips' scanning timings through GPIO pins to ensure synchronous scanning and data reporting. Specifically, the first synchronization bus SYNCBUS12 and the second synchronization bus SYNCBUS34 both include multiple first GPIO pins, some of which are used for nanosecond-level scanning phase synchronization, and some of which are used for microsecond-level workflow synchronization.

[0055] Further, the third synchronization bus SYNCBUS13 includes multiple second GPIO pins for time-division scanning of the TX channels adjacent to the first sub-touch screen area and the second sub-touch screen area.

[0056] In one embodiment, the first touch chip TC1, the second touch chip TC2, the third touch chip TC3, and the fourth touch chip TC4 are all connected to the central control unit through the REPORTBUS bus.

[0057] In this embodiment, the tasks include at least one of coordinate calculation, finger ID tracking, and gesture recognition.

[0058] In addition, this embodiment also proposes a touch screen structure, including the multi-chip cascaded touch screen scanning synchronization device as described above, and further including multiple TX channels and multiple RX channels.

[0059] Specifically, the TX channels and the RX channels are arranged in a staggered grid-like structure to form a touch screen area; the touch screen area is divided into multiple independent sub-touch screen areas by physical disconnection or non-physical contact; both ends of each TX channel in the sub-touch screen area are simultaneously excited by two touch chips.

[0060] In one embodiment, the touch chips are respectively arranged at both ends of the TX channels; both ends of the TX channels are respectively connected to the oppositely arranged touch chips; both ends of the RX channels are respectively connected to the adjacent touch chips, and the adjacent touch chips are located on the same side of the TX channels. This layout allows the touch chips to control and detect the TX channels and RX channels connected to them, realizing the scanning and touch detection functions of the touch screen. In a capacitive touch screen, the TX channels are responsible for sending signals, while the RX channels are responsible for receiving signals. The touch chip determines the touch position by controlling the signals sent by the TX channels and detecting the signal changes received by the RX channels.

[0061] In a specific embodiment, taking two sub-touch screen areas and four touch chips as an example, specifically, a dividing line is provided on the touch screen area, and according to the dividing line, the touch screen area is divided into a first sub-touch screen area and a second sub-touch screen area; the multiple touch chips include a first touch chip TC1, a second touch chip TC2, a third touch chip TC3, and a fourth touch chip TC4.

[0062] Specifically, both ends of the TX channel located in the first area are respectively connected to the relatively arranged first touch chip TC1 and the second touch chip TC2; one end of some of the RX channels located in the first area is connected to the first touch chip TC1, and one end of some of the other RX channels located in the first area is connected to the second touch chip TC2; one end of some of the RX channels located in the second area is connected to the third touch chip TC3, and one end of some of the other RX channels located in the second area is connected to the fourth touch chip TC4.

[0063] Preferably, there is a predetermined distance between the first sub-touch screen area and the second sub-touch screen area, and the range of the predetermined distance is between 10 μm and 50 μm. In this embodiment, precise microfabrication technology is used to perform precise physical disconnection processing on the production of the touch screen sensor (i.e., the touch screen structure), or the touch screen sensor is designed to be in a disconnected state in advance. Specifically, the length of the driving channel (i.e., the TX channel) is twice the length that can be managed by a single touch chip, and the number and length of the sensing channels (i.e., the RX channels) are both twice the number that can be managed by a single touch chip. The touch screen sensing channels can be split into two by precise microfabrication technology or designed to be in a disconnected state. The disconnection width can be strictly controlled between 10 μm and 50 μm to ensure that effective capacitive signal coupling can still be maintained between the two parts after physical disconnection. The length and the manageable number of the driving channels are also correspondingly set to be twice.

[0064] Continue to refer to Figure 2 As shown, in a specific embodiment, at the dividing line (Separator), the touch screen structure is divided into as Figure 2The upper and lower parts shown, namely the first sub-touch screen area and the second sub-touch screen area described above. In the upper part, that is, in the first sub-touch screen area, for the TX electrodes, the left end of the same TX electrode is driven by the TXBUS1 bus of the first touch chip TC1. The TXBUS1 bus consists of 48 TX channels of the first touch chip TC1. The right end of the same TX electrode is driven by the TXBUS2 bus of the second touch chip TC2. The TXBUS2 bus consists of 48 TX channels of the second touch chip TC2. For the RX channels, 72 RX electrodes on the left side of the upper part are managed by the RXBUS1 bus of the first touch chip TC1. The RXBUS1 bus consists of 72 RX channels of the first touch chip TC1. 72 RX electrodes on the right side of the upper part are managed by the RXBUS2 bus of TC2. The RXBUS2 bus consists of 72 RX channels of the second touch chip TC2. When synchronization is required, the first touch chip TC1 and the second touch chip TC2 are synchronized through the first synchronization bus SYNCBUS12. The first synchronization bus SYNCBUS12 includes 4 GPIO pins, two of which are used for nanosecond-level scanning phase synchronization of the touch chip scanning module; the other two are used for microsecond-level workflow synchronization, and the synchronization protocol can be implemented through two-wire protocols such as I2C and custom protocols such as mutual detection of level states.

[0065] In the lower part, that is, in the second sub-touch screen area, for the TX electrodes, the left end of the same TX electrode is driven by the TXBUS3 bus of the third touch chip TC3. The TXBUS3 bus consists of 48 TX channels of the third touch chip TC3. The right end of the same TX electrode is driven by the TXBUS4 bus of the fourth touch chip TC4. The TXBUS4 bus consists of 48 TX channels of the fourth touch chip TC4. For the RX channels, 72 RX channels on the left side of the lower part are managed by the RXBUS3 bus of the third touch chip TC3. The RXBUS3 bus consists of 72 RX channels of the third touch chip TC3. 72 RX channels on the right side of the lower part are managed by the RXBUS4 bus of the fourth touch chip TC4. The RXBUS4 bus consists of 72 RX channels of the fourth touch chip TC4. When synchronization is required, the third touch chip TC3 and the fourth touch chip TC4 are synchronized through the second synchronization bus SYNCBUS34. The second synchronization bus SYNCBUS34 includes 4 GPIO pins, two of which are used for nanosecond-level scanning phase synchronization of the touch chip scanning module, and the other two are used for microsecond-level workflow synchronization, and the synchronization protocol can be implemented through two-wire protocols such as I2C and custom protocols such as mutual detection of level states.

[0066] When the upper and lower parts need to be synchronized, the upper and lower parts are synchronized through the third synchronization bus SYNCBUS13 between the first touch chip TC1 and the third touch chip TC3. The third synchronization bus SYNCBUS13 includes two GPIO pins, which are mainly used for time-sharing scanning of two adjacent TX electrodes of the upper and lower parts, that is, Figure 2 The TX48 electrode in the upper part and the TX1 electrode in the lower part are shown in the figure to avoid noise interference during scanning, which is called the time-sharing scanning strategy in this article. The time-sharing scanning strategy can effectively avoid signal interference and ensure the accuracy and stability of scanning.

[0067] Each touch chip reports the scan data to the central control unit (MCU) through the REPORTBUS bus: the first touch chip TC1 reports data through the REPORTBUS1 bus; the second touch chip TC2 reports data through the REPORTBUS2 bus; the third touch chip TC3 reports data through the REPORTBUS3 bus; the fourth touch chip TC4 reports data through the REPORTBUS4 bus.

[0068] In this embodiment, each REPORTBUS includes an interrupt pin, a reset pin and a communication bus, and the communication bus may include I2C, SPI or a serial port.

[0069] In summary, this embodiment achieves a substantial expansion of the touch screen area and a significant improvement in the scanning synchronization performance through an innovative touch screen sensor design method and an efficient scanning synchronization strategy, which makes this embodiment have a wide range of application prospects in the fields of large touch screens, multi-partition touch screens, and electronic devices requiring high-precision touch operations.

[0070] This embodiment has the following advantages:

[0071] Achieve efficient scanning and synchronization: The time-sharing scanning strategy and synchronous excitation technology are used to ensure the precise synchronization of the scanning waveform. At the same time, the overall scanning time only increases the scanning time of one drive channel, which significantly shortens the scanning time compared to the traditional multi-chip cascade sequential scanning method.

[0072] Improve scanning accuracy and stability: The time-sharing scanning strategy effectively avoids signal interference in the TX channel at the junction of the upper and lower parts, ensures scanning accuracy and stability, and improves the user experience of the touch screen.

[0073] Optimize performance and reserve time resources: The shortened scanning time reserves sufficient time resources for the execution of subsequent advanced algorithms such as communication processing, coordinate calculation of the central control unit, finger ID tracking, and gesture recognition, providing better support for the advanced functions of the touch screen.

[0074] Wide application prospects: This embodiment has wide application prospects in the fields of large touchscreens, multi-zone touchscreens, and electronic devices that require high-precision touch operations, and can meet the requirements of high-precision and high-efficiency touch operations in different scenarios and needs.

[0075] In addition, as shown in Figure 3 Another embodiment of the present invention also proposes a multi-chip cascaded touchscreen scanning synchronization method, which uses the multi-chip cascaded touchscreen scanning synchronization device as described above, or uses the touchscreen structure as described above, and specifically includes the following steps:

[0076] S1. Disconnect the touchscreen structure to form multiple sub-touchscreen areas. Every two touch control chips cooperate to control a selected sub-touchscreen area to achieve synchronization of scanning waveforms and a time-sharing scanning strategy, and obtain scanning data;

[0077] S2. The central control unit coordinates the work of the touch control chips according to the scanning data.

[0078] In this embodiment, the central control unit only controls the power-on sequence of the touch control chips, receives scanning data, calculates coordinates, matches finger IDs, and prevents other abnormalities such as the touch control chips from crashing, and does not directly coordinate the scanning timing. The scanning timing is synchronized by the four touch control chips in this embodiment through a synchronization bus.

[0079] In step S1, the disconnection of the touchscreen structure to form multiple sub-touchscreen areas, and every two touch control chips cooperate to control a selected sub-touchscreen area to achieve synchronization of scanning waveforms and a time-sharing scanning strategy specifically includes: disconnecting the touchscreen structure to form a first sub-touchscreen area and a second sub-touchscreen area; both ends of each TX channel in each sub-touchscreen area are simultaneously excited by two of the touch control chips; the TX channels at the junction of the first sub-touchscreen area and the second sub-touchscreen area are scanned in a time-sharing manner.

[0080] In this embodiment, the time-sharing scanning of the TX channels at the junction of the first sub-touchscreen area and the second sub-touchscreen area specifically includes: the end TX channels adjacent to the second sub-touchscreen area in the first sub-touchscreen area are scanned in time period T1, and the start TX channels adjacent to the first sub-touchscreen area in the second sub-touchscreen area are scanned in time period T2.

[0081] In a specific example, when the terminal TX channels in the first sub-touch screen area need to achieve synchronization of the scanning waveforms, after the first touch control chip TC1 is started, the terminal TX channels are configured, and then it enters a waiting state, waiting for the second touch control chip TC2 to be started; after the second touch control chip TC2 is started, the terminal TX channels are configured, and the first touch control chip TC1 is notified to prepare for synchronization through the first synchronization bus SYNCBUS12; after receiving the synchronization signal, the first touch control chip TC1 triggers the scanning of the terminal TX channels. At the same time, nanosecond-level scanning synchronization with the second touch control chip TC2 is also achieved through the first synchronization bus SYNCBUS12.

[0082] In this embodiment, since the scanning modules of the touch control chips usually have the function of synchronizing the scanning waveforms (phases), multiple chips can be synchronized in terms of the scanning waveforms (i.e., the phases of the scanning signals). Specifically, when both the main chip (host) and the slave chip (slave) enable this synchronization function, the slave chip will be ready first. When the host issues a scanning trigger signal, through two general-purpose input / output (GPIO) pins, the main and slave chips will work together to complete a synchronized waveform scan. In this way, multiple chips can perform touch control scans in a coordinated manner, improving the stability and response speed of the touch control system.

[0083] In a specific example, when the first-end TX channels in the second sub-touch screen area need to achieve synchronization of the scanning waveforms, the first touch control chip TC1 notifies the third touch control chip TC3 to prepare for the synchronization of the first-end TX channels through the third synchronization bus SYNCBUS13; the third touch control chip configures the first-end TX channels, and then enters a waiting state, waiting for the fourth touch control chip TC4 to be started; after the fourth touch control chip TC4 is started, the first-end TX channels are configured, and the third touch control chip TC3 is notified to prepare for synchronization through the second synchronization bus SYNCBUS34; after receiving the synchronization signal, the third touch control chip TC3 waits for the first touch control chip TC1 to complete the scanning notification of the terminal TX channels. After receiving the scanning notification, the third touch control chip TC3 triggers the scanning of the first-end TX channels. At the same time, nanosecond-level scanning synchronization with the fourth touch control chip TC4 is also achieved through the second synchronization bus SYNCBUS34.

[0084] In a specific example, when the remaining TX channels in the first sub-touch screen area and the second sub-touch screen area need to achieve synchronization of the scanning waveforms, after the scanning of the last TX channel in the first sub-touch screen area is completed, the first touch control chip TC1 synchronizes the scanning of the remaining TX channels in the first sub-touch screen area with the second touch control chip TC2 through the first synchronization bus SYNCBUS12. Among them, after each scanning is completed, the second touch control chip TC2 notifies the first touch control chip TC1 to prepare for the scanning of the next TX channel through the first synchronization bus SYNCBUS12. After the scanning of the first TX channel in the second sub-touch screen area is completed, the third touch control chip TC3 synchronizes the scanning of the remaining TX channels in the second sub-touch screen area with the fourth touch control chip TC4 through the second synchronization bus SYNCBUS34. Among them, after each scanning is completed, the fourth touch control chip TC4 notifies the third touch control chip TC3 to prepare for the scanning of the next TX channel through the second synchronization bus SYNCBUS34.

[0085] In step S2, the central control unit coordinates the work of the touch control chips according to the scanning data, which specifically includes: the central control unit receives the scanning data reported by the touch control chips and performs task processing; if there is a touch control chip that has not reported the scanning data, the central control unit will reset and restart all the touch control chips in sequence, that is, the initialization operation. In a specific embodiment, when it is detected that a certain touch control chip appears abnormal, the main touch control chip starts a redundant processing mechanism, resets all the touch control chips, and re-adjusts the scanning timing to ensure the normal operation of the system.

[0086] In this embodiment, initialization and configuration: the MCU resets and starts the first touch control chip TC1, the second touch control chip TC2, the third touch control chip TC3, and the fourth touch control chip TC4 in sequence; after the first touch control chip TC1 is started, it configures the TX48 channels and enters the waiting state, waiting for the second touch control chip TC2 to be started.

[0087] Synchronization of the upper half of the TX48 channels: After the second touch control chip TC2 is started, it configures the TX48 channels and notifies the first touch control chip TC1 to prepare for synchronization through the process synchronization pin of the first synchronization bus SYNCBUS12. After the first touch control chip TC1 receives the synchronization signal, it triggers the scanning of the TX48 channels and realizes nanosecond-level scanning synchronization with the second touch control chip TC2 through the phase synchronization pin of the first synchronization bus SYNCBUS12.

[0088] Synchronization of the lower half TX1 channel: TC1 notifies TC3 through SYNCBUS13 and prepares to synchronize the lower half TX1. The third touch chip TC3 configures the TX1 channel and enters a waiting state, waiting for the fourth touch chip TC4 to start. After the fourth touch chip TC4 starts, it configures the TX1 channel and notifies the third touch chip TC3 to prepare for synchronization through the process synchronization pin of the second synchronization bus SYNCBUS34. After receiving the synchronization signal, the third touch chip TC3 waits for the first touch chip TC1 to complete the scan notification of the TX48 channel. After receiving the notification, the third touch chip TC3 triggers the scan of the TX1 channel, and at the same time achieves nanosecond scanning synchronization with the fourth touch chip TC4 through the phase synchronization pin of the second synchronization bus SYNCBUS34.

[0089] Synchronization of other channels in the upper and lower parts: After the scanning of the TX48 channel in the upper part is completed, the first touch chip TC1 continues to scan the TX1 to TX47 channels in the upper part synchronously with the second touch chip TC2 through the first synchronization bus SYNCBUS12. In this process, the first touch chip TC1 and the second touch chip TC2 achieve nanosecond synchronization through the phase synchronization pin of the first synchronization bus SYNCBUS12, and achieve microsecond synchronization through the process synchronization pin. After each scan is completed, the second touch chip TC2 notifies the first touch chip TC1 through the process synchronization pin to prepare for the next TX channel scan. After the scanning of the TX1 channel in the lower part is completed, the third touch chip TC3 continues to scan the TX2 to TX48 channels in the lower part synchronously with the fourth touch chip TC4 through the second synchronization bus SYNCBUS34. In this process, the third touch chip TC3 and the fourth touch chip TC4 achieve nanosecond synchronization through the phase synchronization pin of the second synchronization bus SYNCBUS34, and achieve microsecond synchronization through the process synchronization pin. After each scan is completed, the fourth touch chip TC4 notifies the third touch chip TC3 through the process synchronization pin to prepare for the next TX channel scan. Simultaneous scanning of the upper and lower parts: Except for the TX48 channel in the upper part and the TX1 channel in the lower part, which need to be scanned in time, the other parts can be scanned at the same time. The touch chips in the upper and lower parts can achieve synchronous scanning under the coordination of the phase synchronization and process synchronization pins to avoid mutual interference.

[0090] When the upper part is synchronized, the first touch chip TC1 is the host and the second touch chip TC2 is the slave. When the lower part is synchronized, the third touch chip TC3 is the host and the fourth touch chip TC4 is the slave. When the upper and lower parts are synchronized, the first touch chip TC1 is the host and the third touch chip TC3 is the slave.

[0091] Data reporting: The first touch chip TC1, the second touch chip TC2, the third touch chip TC3, and the fourth touch chip TC4 sequentially report the scanned data to the MCU via their respective synchronization buses REPORTBUS. The MCU must receive the data reports from the 4 touch chips within one cycle. If a touch chip fails to report data within one cycle, the MCU will reset and restart the first touch chip TC1, the second touch chip TC2, the third touch chip TC3, and the fourth touch chip TC4 in sequence to ensure the normal operation of the system.

[0092] Therefore, in this embodiment, through the optimized synchronization timing and process, the efficient and accurate scanning and data processing of the large-size touch screen are ensured. It can not only avoid the interference between adjacent electrodes but also make full use of the synchronization mechanism to achieve efficient touch detection.

[0093] In summary, a multi-chip cascaded touch screen scanning synchronization device, method, and touch screen structure proposed by the present invention have the following advantages:

[0094] In this embodiment, every two touch chips are used to jointly control a selected sub-touch screen area, and both ends of each TX channel in the sub-touch screen area are simultaneously excited by two touch chips to achieve the synchronization of the scanning waveform; the central control unit is used to receive the scanned data from the touch chips and execute tasks according to the scanned data. It can achieve a large-scale expansion of the touch screen area, thereby achieving efficient scanning and synchronization of the touch screen, and the scanning time only needs to increase the scanning time of one driving channel.

[0095] In addition, the present invention divides the touch screen structure into multiple independent parts, namely sub-touch screen areas, through physical disconnection or non-physical contact design, and each part is controlled by a separate touch chip, realizing the synchronization of the scanning waveform and the improvement of the overall scanning efficiency.

[0096] In addition, for the TX channels at the junction of the upper and lower parts of the present invention, a time-sharing scanning strategy is adopted to effectively avoid signal interference and ensure the accuracy and stability of scanning.

[0097] Therefore, the present invention can expand the area of the touch screen by several times, and compared with the traditional single large-channel chip or multi-chip cascaded sequential scanning method, the overall scanning time is significantly shortened. It reserves sufficient time resources for the execution of subsequent high-level algorithms such as communication processing, coordinate calculation of the central control unit, finger ID tracking, and gesture recognition; making the present invention have a wide range of application prospects in the fields of large touch screens, multi-zone touch screens, and electronic devices that require high-precision touch operations.

[0098] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A multi-chip cascade touch screen scanning synchronization device, characterized in that: include: Multiple touch chips and central control unit; Every two of the touch control chips cooperatively control a selected sub-touch screen area, and both ends of each TX channel in the sub-touch screen area are simultaneously stimulated by the two touch control chips; The central control unit is used to receive the scan data from the touch chip and perform tasks according to the scan data; The touch control chips are connected to each other via a synchronous bus, and the synchronous bus is used to transmit a synchronous signal; one of the multiple touch control chips is set as a master touch chip, and the other touch control chips are set as slave touch chips; the master touch chip is used to generate the synchronous signal and send the synchronous signal to the slave touch chip via the synchronous bus; the slave touch chip performs synchronous scanning according to the received synchronous signal; The synchronization bus includes multiple first GPIO pins and multiple second GPIO pins; a part of the first GPIO pins are used for nanosecond scanning phase synchronization, and another part of the first GPIO pins are used for microsecond workflow synchronization; and multiple second GPIO pins are used for time-sharing scanning of TX channels adjacent to the first sub-touch screen area and the second sub-touch screen area.

2. The multi-chip cascade touch screen scanning synchronization device as claimed in claim 1, characterized in that: The touch control chip includes a TXBUS bus and an RXBUS bus; the TXBUS bus is used to drive the TX electrode connected to the TX channel; the RXBUS bus is used to sense the RX electrode connected to the RX channel.

3. The multi-chip cascade touch screen scanning synchronization device as claimed in claim 2, characterized in that: The plurality of touch control chips include a first touch control chip, a second touch control chip, a third touch control chip and a fourth touch control chip; The TXBUS bus of the first touch chip is used to connect one end of the TX channel in the first sub-touch screen area, and the RXBUS bus of the first touch chip is used to connect part of the RX channels in the first sub-touch screen area; The TXBUS bus of the second touch chip is used to connect the other end of the TX channel in the first sub-touch screen area, and the RXBUS bus of the second touch chip is used to connect the remaining RX channels in the first sub-touch screen area; The TXBUS bus of the third touch chip is used to connect one end of the TX channel in the second sub-touch screen area, and the RXBUS bus of the third touch chip is used to connect part of the RX channels in the second sub-touch screen area; The TXBUS bus of the fourth touch chip is used to connect the other end of the TX channel in the second sub-touch screen area, and the RXBUS bus of the fourth touch chip is used to connect the remaining RX channels in the second sub-touch screen area; The first touch chip and the second touch chip are synchronized via a first synchronization bus; the third touch chip and the fourth touch chip are synchronized via a second synchronization bus; and the first touch chip and the third touch chip are synchronized via a third synchronization bus.

4. The multi-chip cascade touch screen scanning synchronization device as claimed in claim 3, characterized in that: The first synchronization bus and the second synchronization bus both include a plurality of the first GPIO pins, a portion of the first GPIO pins are used for nanosecond level scanning phase synchronization, and another portion of the first GPIO pins are used for microsecond level workflow synchronization.

5. The multi-chip cascade touch screen scanning synchronization device as claimed in claim 3, characterized in that: The third synchronous bus includes a plurality of the second GPIO pins, which are used for time-sharing scanning of TX channels adjacent to the first sub-touch screen area and the second sub-touch screen area.

6. The multi-chip cascade touch screen scanning synchronization device as claimed in claim 4, characterized in that: The first touch control chip, the second touch control chip, the third touch control chip and the fourth touch control chip are all connected to the central control unit via a REPORTBUS bus.

7. The multi-chip cascade touch screen scanning synchronization device as claimed in claim 1, characterized in that: The task includes at least one of coordinate calculation, finger ID tracking and gesture recognition.

8. A touch screen structure, comprising the multi-chip cascade touch screen scanning synchronization device according to any one of claims 1 to 7, characterized in that: It also includes multiple TX channels and multiple RX channels; the TX channels and the RX channels are arranged alternately to form a touch screen area; the touch screen area is divided into multiple independent sub-touch screen areas by physical disconnection or non-physical contact; both ends of each TX channel in the sub-touch screen area are simultaneously stimulated by two touch chips.

9. The touch screen structure according to claim 8, characterized in that: A dividing line is provided on the touch screen area, and the touch screen area is divided into a first sub-touch screen area and a second sub-touch screen area according to the dividing line; the plurality of touch control chips include a first touch control chip, a second touch control chip, a third touch control chip and a fourth touch control chip; Both ends of the TX channels located in the first area are respectively connected to the first touch chip and the second touch chip that are oppositely arranged; one end of some of the RX channels located in the first area is connected to the first touch chip, and one end of other RX channels located in the first area is connected to the second touch chip; the other end of some of the RX channels located in the second area is connected to the third touch chip, and one end of other RX channels located in the second area is connected to the fourth touch chip.

10. The touch screen structure according to claim 9, characterized in that: There is a predetermined distance between the first sub touch screen area and the second sub touch screen area, and the predetermined distance ranges from 10 μm to 50 μm.

11. A multi-chip cascade touch screen scanning synchronization method, using the multi-chip cascade touch screen scanning synchronization device as described in any one of claims 1 to 7, or using the touch screen structure as described in any one of claims 8 to 10, characterized in that: The details include: The touch screen structure is disconnected to form multiple sub-touch screen areas, and each two touch chips cooperate to control a selected sub-touch screen area to achieve synchronization of scanning waveforms and time-sharing scanning strategy, and obtain scanning data; The central control unit coordinates the operation of the touch control chip according to the scanning data.

12. The multi-chip cascade touch screen scanning synchronization method according to claim 11, characterized in that: The disconnected touch screen structure forms multiple sub-touch screen areas, and each two touch control chips collaboratively control a selected sub-touch screen area to achieve synchronization of scanning waveforms and time-sharing scanning strategies, specifically including: The touch screen structure is disconnected to form a first sub-touch screen area and a second sub-touch screen area; both ends of each TX channel in each sub-touch screen area are stimulated simultaneously by two touch control chips; and the TX channel at the junction of the first sub-touch screen area and the second sub-touch screen area is scanned in time division.

13. The multi-chip cascade touch screen scanning synchronization method according to claim 12, characterized in that: The time-sharing scanning of the TX channel at the junction of the first sub-touch screen area and the second sub-touch screen area specifically includes: scanning the end TX channel adjacent to the second sub-touch screen area in the first sub-touch screen area within a time period T1, and scanning the head end TX channel adjacent to the first sub-touch screen area in the second sub-touch screen area within a time period T2.

14. The multi-chip cascade touch screen scanning synchronization method according to claim 13, characterized in that: When the terminal TX channel in the first sub-touch screen area needs to realize synchronization of the scanning waveform, after the first touch chip is started, the terminal TX channel is configured, and then enters a waiting state, waiting for the second touch chip to start; after the second touch chip is started, the terminal TX channel is configured, and the first touch chip is notified to prepare for synchronization through the first synchronization bus; after receiving the synchronization signal, the first touch chip triggers the scanning of the terminal TX channel, and at the same time, realizes nanosecond scanning synchronization with the second touch chip through the first synchronization bus.

15. The multi-chip cascade touch screen scanning synchronization method according to claim 13, characterized in that: When the head-end TX channel in the second sub-touch screen area needs to realize synchronization of the scanning waveform, the first touch chip notifies the third touch chip through the third synchronization bus to prepare for the synchronization of the head-end TX channel; the third touch chip configures the head-end TX channel, and then enters a waiting state, waiting for the fourth touch chip to start; after the fourth touch chip is started, the head-end TX channel is configured, and the third touch chip is notified through the second synchronization bus to prepare for synchronization; after receiving the synchronization signal, the third touch chip waits for the first touch chip to complete the scanning notification of the terminal TX channel, and after receiving the scanning notification, the third touch chip triggers the scanning of the head-end TX channel, and at the same time, realizes nanosecond scanning synchronization with the fourth touch chip through the second synchronization bus.

16. The multi-chip cascade touch screen scanning synchronization method according to claim 13, characterized in that: When the remaining TX channels in the first sub-touch screen area and the second sub-touch screen area need to realize synchronization of scanning waveforms, after the terminal TX channel in the first sub-touch screen area is scanned, the first touch chip scans the remaining TX channels in the first sub-touch screen area synchronously with the second touch chip through the first synchronization bus; wherein, after each scan is completed, the second touch chip notifies the first touch chip through the first synchronization bus to prepare for scanning the next TX channel; After the scanning of the head-end TX channel in the second sub-touch screen area is completed, the third touch chip scans the remaining TX channels in the second sub-touch screen area synchronously with the fourth touch chip through the second synchronization bus; wherein, after each scanning is completed, the fourth touch chip notifies the third touch chip through the second synchronization bus to prepare for scanning the next TX channel.

17. The multi-chip cascade touch screen scanning synchronization method according to claim 11, characterized in that: The central control unit coordinates the work of the touch chip according to the scanning data, specifically including: the central control unit receives the scanning data reported by the touch chip and performs task processing; if there is a touch chip that does not report the scanning data, the central control unit will reset and restart all the touch chips in turn, that is, the initialization operation.

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