Touch panel and touch input system

Abstract

A touch input system includes a touch panel for sending an uplink signal, and an active stylus for analyzing the uplink signal and communicating with the touch panel in a bidirectional manner according to a timing synchronized with the touch panel. The uplink signal includes a preamble for timing synchronization, a digital information for bidirectional communication between the active stylus and the touch panel, and a cyclic redundancy check for performing a data error detection or an error correction.

Description

TECHNICAL FIELD

[0001] The present application relates to a touch panel and a touch input system, and more particularly to a touch panel and a touch input system for improving the transmission amount of uplink signals within a limited time. BACKGROUND

[0002] With the progress of technology, touch sensing technology continues to improve, in which the touch pen directly input to the touch panel becomes popular because it can simulate the feeling of traditional writing tools and is easy to operate.

[0003] The current way of operating a capacitive touch panel with a touch pen is roughly divided into active touch and passive touch. The input method of active touch is to touch with an active stylus, but the contact time of each touch is very short, so the time for the touch panel and the active stylus to transmit uplink signals is very limited. In order to effectively shorten the occupation time of uplink signals, the amount of data in the uplink signals is greatly reduced in the prior art, thus sacrificing the flexibility of the communication protocol. Or in order to shorten the occupation time of uplink signals, the data to be transmitted is transmitted by an additional communication device, such as using a Bluetooth device, thus also increasing many costs. In this case, how to improve the transmission amount of uplink signals between the touch panel and the active stylus within a limited time has become one of the issues of concern in the industry. SUMMARY

[0004] Therefore, the main purpose of the present application is to provide a touch panel and a touch input system to improve the transmission amount of uplink signals between the touch panel and the active stylus.

[0005] The present application provides a touch panel, comprising: a memory; a sending module; and a touch panel controller; wherein the touch panel controller controls the sending module to send an uplink signal to synchronize timing and bidirectionally communicate with an active stylus; wherein the uplink signal comprises: a preamble stored in the memory for synchronizing timing; a digital information for bidirectional communication between the active stylus and the touch panel; and a cyclic redundancy check for performing a data error detection or an error correction; wherein the uplink signal comprises a plurality of bit data, wherein the plurality of bit data comprises at least four bit data, the preamble comprises at least two bit data, the digital information comprises at least one bit data, and the cyclic redundancy check comprises at least one bit data.

[0006] The present application provides a touch input system, comprising: a touch panel for sending an uplink signal; and an active stylus for analyzing the uplink signal and communicating with the touch panel in a bidirectional manner according to the uplink signal in a synchronized timing; wherein the uplink signal comprises: a preamble for synchronizing timing; a digital information for the active stylus and the touch panel to communicate in a bidirectional manner; and a cyclic redundancy check for performing a data error detection or an error correction; wherein the uplink signal comprises a plurality of bit data, wherein the plurality of bit data comprises at least four bit data, the preamble comprises at least two bit data, the digital information comprises at least one bit data, and the cyclic redundancy check comprises at least one bit data. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 FIG. 1 is a schematic diagram of a touch input system according to an embodiment of the present application.

[0008] Figure 2 FIG. 2 is a flowchart of a method for connecting a touch panel and an active stylus according to an embodiment of the present application.

[0009] Figure 3 FIG. 3 is a schematic diagram of an uplink signal transmitted by using a maximum length sequence code according to the prior art.

[0010] Figure 4 FIG. 4 is a schematic diagram of an uplink signal according to an embodiment of the present application.

[0011] Figure 5 FIG. 5 is a waveform diagram of a maximum length sequence code according to an embodiment of the present application.

[0012] REFERENCE NUMERALS

[0013] 1: touch input system

[0014] 2: flow

[0015] 10: touch panel

[0016] 102: memory

[0017] 104: touch panel controller

[0018] 106: sending module

[0019] 20: active stylus

[0020] 202: active stylus controller

[0021] 204: receiving module DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with the drawings and specific embodiments.

[0023] Referring to Figure 1 , Figure 1 Figure 1 is a schematic diagram of an embodiment of a touch input system 1. The touch input system 1 comprises a touch panel 10 and an active stylus 20. The touch panel 10 comprises a memory 102, a touch panel controller 104, and a sending module 106. The active stylus 20 comprises an active stylus controller 202 and a receiving module 204. When the active stylus 20 contacts the touch panel 10, the touch panel 10 and the active stylus 20 establish a connection to synchronize timing and communicate bidirectionally. Note that the touch input system 1 only represents the necessary elements required to establish a connection to synchronize timing, and the basic architecture is well known in the art, so it is not described in detail.

[0024] The method of establishing a connection between the touch panel 10 and the active stylus 20 in the touch input system 1 can be summarized as a flow 2, as shown in Figure 2 . The flow 2 comprises the following steps:

[0025] Step S200: Start.

[0026] Step S202: The touch panel controller 104 controls the sending module 106 to send an uplink signal at a regular time.

[0027] Step S204: The active stylus controller 202 controls the receiving module 204 to receive the uplink signal.

[0028] Step S206: The active stylus 20 analyzes the uplink signal to synchronize timing with the touch panel 10 and communicate bidirectionally.

[0029] Step S208: End.

[0030] According to the flow 2, in step S202, the touch panel controller 104 must send a synchronization signal in time, and the active stylus 20 can synchronize the timing with the touch panel 10 according to the synchronization signal, so as to establish the connection between the active stylus 20 and the touch panel 10. Therefore, the touch panel controller 104 controls the sending module 106 to send an uplink signal to the active stylus 20. The uplink signal contains a preamble, a digital information and a cycle redundancy check (CRC). The preamble is a predetermined information for synchronizing the timing, and is stored in the storage 102; the digital information is used for the active stylus 20 and the touch panel 10 to communicate with each other; and the cycle redundancy check is used for data error detection or error correction. In detail, the uplink signal sent by the touch panel 10 uses a plurality of pseudo noise codes (PN code) to send by using a direct sequence spread spectrum (DSSS) technology. The pseudo noise code is a maximum length sequence code (MLS code), a Barker code or a nested Barker code.

[0031] In step S204, the active stylus controller 202 controls the receiving module 204 to receive the uplink signal. In step S206, the active stylus 20 analyzes the uplink signal, and according to the preamble in the uplink signal, the active stylus 20 can synchronize the timing with the touch panel 10, so as to establish the connection between the active stylus 20 and the touch panel 10 and communicate with each other.

[0032] Please refer to Figure 3 , Figure 3Figure 1 is a schematic diagram of an uplink signal 3 transmitted using a maximum length sequence code in the prior art. The preamble in the uplink signal 3 contains 3 bits of data, the digital information contains 25 bits of data, and the cyclic redundancy check contains 5 bits of data. That is, the uplink signal 3 contains a total of 33 bits of data. Each bit of data in the uplink signal 3 is transmitted using a set of maximum length sequence codes composed of 31 chips. In general, each chip takes 1 microsecond (µs) to transmit, so a set of maximum length sequence codes takes 31 microseconds to transmit. In this prior art, the uplink signal 3 containing 33 bits of data takes 1023 microseconds (µs) to transmit. However, if the touch panel 10 is an in-cell touch panel, the display function and the touch function need to use a thin film electrode of the in-cell touch panel in time-sharing manner, so the response time allocated to the touch function is very limited. For example, the response time allocated to the touch function of an amorphous in-cell touch panel is about 170 microseconds, and the response time allocated to the touch function of a low temperature poly-silicon (LTPS) in-cell touch panel is about 250 microseconds. The uplink signal 3 in the prior art takes 1023 microseconds, which exceeds the response time 170-250 microseconds allocated to the touch function of the in-cell touch panel, that is, the uplink signal 3 in the prior art is not suitable for use in the synchronization timing and bidirectional communication of the in-cell touch panel and the active stylus.

[0033] To improve the drawback that transmitting the uplink signal 3 takes too long, the present application uses modulation to convert a plurality of bits of data into a plurality of symbol data, and then uses a plurality of pseudo-noise codes to transmit the plurality of symbol data by using direct sequence spread spectrum technology, to solve the above-mentioned drawback.

[0034] In detail, please refer to Figure 4 , Figure 4FIG. 4 is a schematic diagram of an uplink signal 4 according to an embodiment of the present application. The preamble of the uplink signal 4 includes 12 bits of data, the digital information includes 24 bits of data, and the cyclic redundancy check includes 4 bits of data. In other words, the uplink signal 4 includes a total of 40 bits of data. In detail, the touch panel controller 104 modulates the 12 bits of data of the preamble as 3 flag data, the 24 bits of data of the digital information as 6 flag data, and the 4 bits of data of the cyclic redundancy check as 1 flag data. In other words, the touch panel controller 104 modulates every 4 bits of data as 1 flag data. The touch panel controller 104 then transmits the 10 flag data using 10 pseudo-noise codes by using the direct sequence spread spectrum technique. In detail, each flag data of the uplink signal 4 is transmitted using a set of maximum length sequence codes composed of 24 chips, for example, the flag data Symbol_3 is {1, -1, -1, 1, -1, 1, -1, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1, -1, 1, -1, -1, 1, 1, -1}. Generally, each chip takes 1 microsecond to transmit, and thus a set of maximum length sequence codes takes 24 microseconds to transmit. In the embodiment of the present application, the uplink signal 4 including 10 flag data takes 240 microseconds to transmit. Therefore, if the touch panel 10 is a low temperature poly-silicon in-cell touch panel, the response time allocated to the touch function is about 250 microseconds, and thus the response time of the touch panel controller 104 modulating and transmitting the uplink signal 4 is less than 250 microseconds in the embodiment of the present application. Therefore, the problem of long response time in the prior art is overcome.

[0035] For example, please refer to Table 1 below. Table 1 is a schematic diagram of a set of maximum length sequence codes transmitting 1 flag data according to an embodiment of the present application, wherein 1 flag data represents 4 bits of data. The first row {Data_0, Data_1…, Data_F} of Table 1 is the representation of 4 bits of data, and the second row is the corresponding maximum length sequence code of 4 bits of data.

[0036] Table 1

[0037]

[0038] In detail, for example, the maximum length sequence code 0x569A99 corresponding to Data_1 is {-1, 1, -1, 1, -1, 1, 1, -1, 1, -1, -1, 1, 1, 1, -1, -1, 1, -1, -1, 1, 1, -1, -1, 1}, wherein each number represents one chip, -1 represents low potential, and 1 represents high potential. The waveform of Data_1 is shown in FIG. 4. Figure 5 ​

[0039] In one embodiment, each of the plurality of flag data is either a low correlation, a zero correlation, or a high negative correlation. For example, the maximum length sequence code 0x65AA56 corresponding to flag data Data_0 is {-1, 1, 1, -1, -1, 1, -1, 1, 1, -1, 1, -1, 1, -1, 1, -1, -1, 1, -1, 1, -1, 1, 1, -1} and the maximum length sequence code 0x569A99 corresponding to flag data Data_1 is {-1, 1, -1, 1, -1, 1, 1, -1, 1, -1, -1, 1, 1, 1, -1, -1, 1, -1, -1, 1, 1, -1, -1, 1}, the vector inner product of flag data Data_0 and flag data Data_1 is {1, 1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 1, -1, -1, 1, -1, -1, 1, 1, -1, -1, -1, -1}, and the sum of each number of the vector inner product sum {1, 1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 1, -1, -1, 1, -1, -1, 1, 1, -1, -1, -1, -1} is 0, thus flag data Data_0 and flag data Data_1 are zero correlation. It is noted that each of the plurality of flag data can also be a high negative correlation that is orthogonal. For example, the maximum length sequence code 0x9A55A9 corresponding to flag data Data_8 is {1, -1, -1, 1, 1, -1, 1, -1, -1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, -1, -1, 1}, the vector inner product of flag data Data_0 and flag data Data_8 is {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}, and the sum of each number of the vector inner product sum {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1} is -24, thus flag data Data_0 and flag data Data_8 are orthogonal, that is, a high negative correlation.

[0040] In another embodiment, referring to Table 2 below, the preamble of an uplink signal 5 of the present invention contains 12 bits of metadata, the digital information contains 12 bits of metadata, and the cyclic redundancy check (CRC) contains 4 bits of metadata, meaning the uplink signal 4 contains a total of 28 bits of metadata. Specifically, the touch panel controller 104 modulates the 12 bits of metadata of the preamble into 3 flag data, the 12 bits of digital information into 3 flag data, and the 4 bits of CRC into 1 flag data. In other words, the touch panel controller 104 modulates every 4 bits of metadata into 1 flag data. The touch panel controller 104 then uses 7 pseudo-noise codes to transmit 7 flag data using direct sequence spread spectrum (DSS) technology. Specifically, each flag data in the uplink signal 4 is transmitted using a maximum-length sequence code consisting of 22 slices. Generally, each slice takes 1 microsecond to transmit, meaning a maximum-length sequence code takes 22 microseconds to transmit. In this embodiment of the present invention, the uplink signal 5 containing 7 flag data will take 154 microseconds to transmit. Therefore, if the touch panel 10 is an amorphous embedded touch panel, the response time allocated to the touch function is about 170 microseconds. That is to say, in this embodiment of the invention, the response time of the touch panel controller 104 modulating and sending the uplink signal 5 is less than 170 microseconds, thus overcoming the problem of excessively long response time in the prior art.

[0041] Table 2

[0042]

[0043] In another embodiment, referring to Table 2, the preamble of an uplink signal 6 in this invention contains 12 bits of metadata, the digital information contains 16 bits of metadata, and the cyclic redundancy check (CRC) contains 4 bits of metadata, meaning the uplink signal 6 contains a total of 32 bits of metadata. Specifically, the touch panel controller 104 modulates the 12 bits of metadata of the preamble into 3 flag data, the 16 bits of digital information into 4 flag data, and the 4 bits of CRC into 1 flag data. In other words, the touch panel controller 104 modulates every 4 bits of metadata into 1 flag data. The touch panel controller 104 then uses direct sequence spread spectrum technology with 5 pseudo-noise codes composed of 30 slices to transmit the flag data of the 4 bits of digital information and the flag data of the CRC, and 3 pseudo-noise codes composed of 32 slices to transmit the flag data of the 3 bits of preamble. Generally, each slice takes 1 microsecond to transmit. In this embodiment of the invention, the uplink signal 6 containing 8 flag data will take 246 microseconds to transmit. Therefore, if the touch panel 10 is a low-temperature polysilicon embedded touch panel, the response time allocated to the touch function is about 246 microseconds. That is to say, in this embodiment of the invention, the response time of the touch panel controller 104 modulating and sending the uplink signal 6 is less than 250 microseconds, thus overcoming the problem of excessively long response time in the prior art.

[0044] Furthermore, referring to Table 2, the uplink signal of the present invention consists of a plurality of slices, which can be further divided into a plurality of flag data. Each flag data contains a plurality of bits. The ratio of the number of slices of the preamble in the uplink signal to the number of bits contained in each flag data of the preamble is not greater than 12. The ratio of the number of slices of the digital information and the cyclic redundancy check in the uplink signal to the number of bits contained in each flag data of the digital information and the cyclic redundancy check is not greater than 12.

[0045] It should be noted that the touch input system 1 is an embodiment of the present invention. Those skilled in the art can combine, modify, or change the above-described embodiments in accordance with the spirit of the present invention, and are not limited thereto. All the above descriptions, steps, and / or processes (including suggested steps) can be implemented by hardware, software, firmware (i.e., a combination of hardware devices and computer instructions, where the data in the hardware device is read-only software data), electronic systems, or combinations of the above devices. Hardware may include analog circuits, digital circuits, and / or mixed circuits (i.e., microcircuits, microchips, or silicon chips). Electronic systems may include system-on-chip (SoC), system-in-package (SiP), computer-on-module (CoM), and touch input system 1. The process steps and embodiments of the present invention can exist in the form of program code or instructions and be stored in memory 102. The memory 102 may be a computer-readable storage medium, and may include, but is not limited to, read-only memory (ROM), flash memory, random-access memory (RAM), a subscriber identity module (SIM), hard disk, floppy disk, or optical disk read-only memory (CD-ROM / DVD-ROM / BD-ROM). The above processes and embodiments may be compiled into program code or instructions and stored in the memory 102. The touch panel controller 104 may be used to read and execute the program code or instructions stored in the memory 102 to implement all the aforementioned steps and functions.

[0046] In summary, compared to the 1023 microseconds required for uplink signal transmission in existing technologies, which exceeds the 170-250 microsecond response time allocated to touch functions in embedded touch panels, the present invention modulates a complex number of bits of metadata in the uplink signal into a complex number of flag data, and then uses direct sequence spread spectrum technology to transmit the uplink signal using a pseudo-noise code composed of a complex number of slices. This makes the response time for transmitting the uplink signal in the embodiments of the present invention less than 170-250 microseconds, thus overcoming the problem of excessively long response time in existing technologies.

[0047] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several equivalent substitutions or obvious modifications can be made without departing from the concept of the present invention, and all such modifications, achieving the same performance or purpose, should be considered within the scope of protection of the present invention.

Claims

1. A touch panel, characterized in that, include: A memory; One sending module; as well as A touch panel controller; wherein the touch panel controller controls the transmitting module to send an uplink signal to synchronize timing with an active stylus and communicate bidirectionally; wherein the uplink signal includes: A preamble, stored in the memory, is used for timing synchronization; A digital message is used for bidirectional communication between the active stylus and the touch panel; as well as A cyclic redundancy check is used to perform a data error detection or an error correction. The uplink signal contains a complex number of metadata bits, wherein the complex number of metadata bits contains at least four metadata bits, the preamble contains at least two metadata bits, the digital information contains at least one metadata bit, and the cyclic redundancy check contains at least one metadata bit. The complex number of bits of data in the uplink signal are modulated into a complex number of flag data and transmitted using a complex number of pseudo-noise codes with direct sequence spread spectrum technology. Each of the complex number of flag data contains a complex number of bits.

2. The touch panel as described in claim 1, characterized in that: The ratio of the number of slices of the preamble to the number of bits contained in each flag data of the preamble is no greater than 12.

3. The touch panel as described in claim 1, characterized in that: The ratio of the number of slices of the digital information and the multiple slices of the cyclic redundancy check to the number of bits contained in each flag data of the digital information and the cyclic redundancy check is no greater than 12.

4. The touch panel as described in claim 1, characterized in that: The multiple flag data of the preamble are lowly correlated with the multiple flag data of the digital information.

5. The touch panel as described in claim 1, characterized in that: Each of the first half of the plurality of flag data in the digital information is lowly correlated with each other, each of the second half is lowly correlated with each other, and the flag data in the first half and the second half are highly correlated with each other.

6. The touch panel as described in claim 1, characterized in that: The pseudo-noise code is a Barker code or an embedded Barker code.

7. The touch panel as described in claim 1, characterized in that: The touch panel is an embedded touch panel.

8. A touch input system, characterized in that, include: A touch panel is used to send an uplink signal; as well as An active stylus is used to analyze the uplink signal and synchronize the timing with the touch panel and communicate bidirectionally according to the uplink signal. The uplink signal includes: A preamble is used for timing synchronization; A digital message is used for bidirectional communication between the active stylus and the touch panel; as well as A cyclic redundancy check is used to perform a data error detection or an error correction. The uplink signal contains a complex number of metadata bits, wherein the complex number of metadata bits contains at least four metadata bits, the preamble contains at least two metadata bits, the digital information contains at least one metadata bit, and the cyclic redundancy check contains at least one metadata bit. The complex number of bits of data in the uplink signal are modulated into a complex number of flag data and transmitted using a complex number of pseudo-noise codes with direct sequence spread spectrum technology. Each of the complex number of flag data contains a complex number of bits.

9. The touch input system as described in claim 8, characterized in that: The ratio of the number of slices of the preamble to the number of bits contained in each flag data of the preamble is no greater than 12.

10. The touch input system as described in claim 8, characterized in that: The ratio of the number of slices of the digital information and the multiple slices of the cyclic redundancy check to the number of bits contained in each flag data of the digital information and the cyclic redundancy check is no greater than 12.

11. The touch input system as described in claim 8, characterized in that: The multiple flag data of the preamble are lowly correlated with the multiple flag data of the digital information.

12. The touch input system as described in claim 8, characterized in that: Each of the first half of the plurality of flag data in the digital information is lowly correlated with each other, each of the second half is lowly correlated with each other, and the flag data in the first half and the second half are highly correlated with each other.

13. The touch input system as described in claim 8, characterized in that: The pseudo-noise code is a Barker code or an embedded Barker code.

14. The touch input system as described in claim 8, characterized in that: The touch panel is an embedded touch panel.

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