Touch display device and operation method thereof

Abstract

The invention provides a touch display device and an operation method thereof. The touch display device comprises a signal receiver, an analog-to-digital converter, a signal transmitter and a processor. The signal receiver receives a downlink signal from the active stylus. The downlink signal comprises an analog touch signal. The analog-to-digital converter converts the analog touch signal into sampling data. When the touch display device is in a low-frequency operation mode, the processor reduces the carrier frequency of the downlink signal provided by the active stylus through the signal transmitter and the uplink signal. The processor reduces the sampling frequency of the analog-to-digital converter and performs touch sensing according to the sampling data.

Description

Technical Field

[0001] The present invention relates to a touch display technology and a touch pen application technology, and in particular to a touch display device and an operation method thereof. Background Art

[0002] The integration of a display panel and a touch panel into a touch display device is a common application at present. On the other hand, the touch display device communicates with a supported active stylus and obtains a touch signal from the downlink of the active stylus to determine the touch position of the active stylus on the touch display device. However, when the active stylus is enabled, both the touch display device and the active stylus consume a large amount of power due to the normal communication. Summary of the invention

[0003] The present invention is directed to a touch display device and an operating method thereof, which reduces the power consumption of the touch display device and an active touch pen by adjusting a signal carrier frequency and a sampling frequency of an analog-to-digital converter, thereby saving power.

[0004] According to an embodiment of the present invention, a touch display device includes a signal receiver, an analog-to-digital converter, a signal transmitter, and a processor. The signal receiver receives a downlink signal from an active stylus, wherein the downlink signal includes an analog touch signal. An analog-to-digital converter (ADC) is coupled to the signal receiver. The ADC converts the analog touch signal into sampled data. The signal transmitter sends an uplink signal to the active stylus. The carrier frequency of the downlink signal provided by the active stylus is adjusted based on the uplink signal. The processor is coupled to the analog-to-digital converter and the signal transmitter. When the touch display device is in a low-frequency operating mode, the processor reduces the carrier frequency of the downlink signal provided by the active stylus through the signal transmitter and the uplink signal. The processor reduces the sampling frequency of the analog-to-digital converter and performs touch sensing based on the sampled data.

[0005] According to an embodiment of the present invention, an operating method of a touch display device comprises the following steps: obtaining a downlink signal from the active stylus, wherein the downlink signal comprises an analog touch signal; converting the analog touch signal into sampling data based on an analog-to-digital converter, and performing touch sensing based on the sampling data; in a low-frequency operation mode of the touch display device, lowering the carrier frequency of the downlink signal provided by the active stylus through an uplink signal; and reducing the sampling frequency of the analog-to-digital converter, and performing touch sensing based on the sampling data.

[0006] Based on the above, the touch display device, touch display system and operation method thereof described in the embodiment of the present invention is that when the touch display device enters the low-frequency operation mode from the high-frequency operation mode, the processor in the touch display device first reduces the carrier frequency of the downlink signal provided by the active stylus through the uplink signal, thereby reducing the power consumption of the active stylus. On the other hand, the processor also dynamically adjusts the sampling frequency of the ADC, and determines whether the signal-to-noise ratio (SNR) in the sampled data provided by the ADC is applicable or higher than that required by the touch display system, thereby selectively reducing the sampling frequency of the ADC to save the power consumption of the ADC and subsequent digital circuits in operation, thereby making the touch display device as a whole more power-saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram of a touch display system according to an embodiment of the present invention;

[0008] Figure 2A and Figure 2B It is the waveform diagram of each signal in the touch display system;

[0009] Figure 3 is a flow chart of an operating method of a touch display device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0010] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0011] Figure 1 1 is a schematic diagram of a touch display system according to an embodiment of the present invention. The touch display system includes a touch display device 100 and an active stylus 105. The touch display device 100 mainly includes a signal receiver 110 (e.g., an analog front end circuit), an analog-to-digital converter (ADC) 120, a processor 130, and a signal transmitter 140. The active stylus 105 includes a receiving circuit 106 and a transmitting circuit 107.

[0012] The receiving circuit 106 can obtain the uplink signal in the uplink 104 from the signal transmitter 140 of the touch display device 100. When the touch display device 100 is just started, the processor 130 can send an uplink signal through the signal transmitter 140 to set the carrier frequency of the downlink signal of the active stylus 105 to a first carrier frequency value (e.g., 400kHz) as the default carrier frequency of the downlink signal. Alternatively, the transmission circuit 107 in the active stylus 105 has the default carrier frequency of the downlink signal in the downlink 102 when it is started. In this embodiment, the communication protocol of the active stylus 105 usually uses the highest frequency carrier frequency in the downlink signal as the default carrier frequency (here, it is assumed to be 400kHz).

[0013] The signal receiver 110 of the touch display device 100 receives a downlink signal from the active stylus 105. The downlink signal includes an analog touch signal. An analog-to-digital converter (ADC) 120 is coupled to the signal receiver 110. The ADC 120 converts the analog touch signal into sampled data.

[0014] The signal transmitter 140 is controlled by the processor 130. The signal transmitter 140 sends an uplink signal to the active stylus 105. The carrier frequency of the downlink signal provided by the active stylus 105 may be adjusted based on the uplink signal.

[0015] The processor 130 is coupled to the ADC 120 and the signal transmitter 140. The processor 130 includes a touch signal processor 132, a signal-to-noise ratio adjuster 134, and a timing controller 136. The touch signal processor 132 is coupled to the ADC 120. The touch signal processor 132 receives the sampled data provided by the ADC 120 after sampling, and performs touch sensing. The "touch sensing" described in this embodiment refers to determining the position of the active stylus 105 on the touch screen of the touch display device 100 through the touch signal in the sampled data.

[0016] The signal-to-noise ratio adjuster 134 is coupled to the touch signal processor 132. The signal-to-noise ratio adjuster 134 calculates the signal-to-noise ratio of the sampled data according to the sampled data, and compares the signal-to-noise ratio with the initial signal-to-noise ratio range to generate a comparison result. The timing controller 136 is coupled to the signal-to-noise ratio adjuster 134. The timing controller 136 provides an uplink carrier frequency adjustment signal to the signal transmitter 140 based on the aforementioned comparison result, and adjusts the sampling frequency of the ADC 120. Figure 1 The operations of the components in the touch display system may refer to the descriptions of other embodiments.

[0017] Figure 2A and Figure 2B is a waveform diagram of each signal in the touch display system. Please also refer to Figure 1 and Figure 2AIn part (a), in the high-frequency operation mode of the touch display device 100, the processor 130 may send an uplink signal through the signal transmitter 140 to set the carrier frequency of the downlink signal of the active stylus 105 to a first carrier frequency value (e.g., 400 kHz), and set the sampling frequency of the ADC 120 to a first sampling frequency value, that is, Figure 2A The frequency of the sampling signal in part (a) is 1.6 MHz. Specifically, assuming that the carrier frequency is 400 kHz and the number of sampling points sampled by the ADC 120 in the unit period TP1 is greater than or equal to 4 (e.g., there are 4 enabled sampling pulses in the period SH1), the signal-to-noise ratio (SNR) requirement of the overall touch display system for touch sensing can be met. This SNR is set as the initial SNR, and the sampling frequency of the ADC 120 needs to be set to be greater than or equal to 1.6 MHz.

[0018] In the embodiment of the present invention, when the processor 130 sends an uplink signal through the signal transmitter 140 to reduce the carrier frequency of the downlink signal of the active stylus 105, the sampling frequency or sampling data processing of the ADC 120 is dynamically adjusted to save the power consumption of the touch display system. In addition, it is necessary to consider whether the signal-to-noise ratio of the sampled data after being sampled by the ADC 120 meets the SNR requirement of the overall touch display system.

[0019] See also Figure 1 and Figure 2A In part (b), when the touch display device 100 enters the low frequency operation mode from the high frequency operation mode, the processor 130 sends an uplink signal through the signal transmitter 140 to adjust the carrier frequency of the downlink signal of the active stylus 105 from the first carrier frequency value (e.g., 400kHz) to the second carrier frequency value (e.g., 200kHz). The first carrier frequency value (400kHz) of this embodiment is higher than the second carrier frequency value (200kHz). After adjusting the carrier frequency of the downlink signal, the processor 130 obtains the sampled data based on the ADC 120.

[0020] The processor 130 can dynamically reduce the sampling frequency of the ADC 120. For example, when the carrier frequency of the downlink signal of the active stylus 105 is set to the second carrier frequency value (200kHz), if the sampling frequency of the ADC 120 remains unchanged and remains at 1.6MHz as when the first carrier frequency value (e.g., 400kHz), the sampling points sampled in the unit time period TP2 will increase to 8. When the processor 130 dynamically reduces the sampling frequency of the ADC 120, the sampling points sampled in the unit time period TP2 is greater than or equal to 4 (e.g., the sampling point is equal to 6), so that the signal-to-noise ratio of the sampled data can meet the SNR requirements of the overall touch display system. The processor 130 of the present embodiment can set the sampling frequency of the sampling signal in the ADC 120 to the second sampling frequency value (e.g., 800kHz), the sampling points sampled in the unit period TP2 are still equal to 4, and the periods SH1 and SH2 also have 4 enabled sampling pulses, so that the signal-to-noise ratio of the sampled data can meet the SNR requirements of the overall touch display system. In this way, when the SNR after reducing the sampling frequency of the ADC 120 still meets the SNR requirements of the overall touch display system, the power consumption of the ADC 120 can be reduced, and the power consumption of the back-end digital circuit can also be reduced. In other words, the processor 130 of the present embodiment dynamically reduces the sampling frequency of the ADC 120 according to the signal-to-noise ratio of the sampled data provided by the ADC 120, and performs touch sensing according to the sampled data.

[0021] Figure 2A Part (b) is achieved by reducing the frequency of the sampling signal in ADC 120. Figure 2B The sampling data processing times are reduced, for example, the processor 130 performs sampling data processing only once at two sampling points, as shown by arrow 205. When the carrier frequency of the downlink signal in the active stylus 105 is set to the second carrier frequency value (200kHz) and the sampling frequency sampled in the unit time period TP3 remains unchanged, the sampling point is equal to 8, and the processor 130 can be adjusted to perform sampling data processing 4 times.

[0022] Figure 3 is a flow chart of an operation method of a touch display device 100 according to an embodiment of the present invention. Figure 1 and Figure 3 In step S302, the operation method starts. In step S305, Figure 1The processor 130 determines the transmission carrier frequency of the initial downlink signal (e.g., the first carrier frequency value / 400kHz) and the sampling frequency of the ADC 120 (e.g., the first sampling frequency value / 1.6MHz) to obtain sampling data and perform touch sensing. In step S310, the processor 130 determines whether to enter the low-frequency operation mode. The low-frequency operation mode can be set by the user through the touch display device 100, or the touch display device 100 automatically enters after running for a preset period of time, or enters due to other situations that require frequency reduction. The application of this embodiment can determine how to make the touch display device 100 enter the low-frequency operation mode from the high-frequency operation mode according to its needs.

[0023] In step S320 , the processor 130 lowers the carrier frequency of the downlink signal of the active stylus 105 through the uplink signal, for example, from a first carrier frequency value (eg, 400 kHz) to a second carrier frequency value (eg, 200 kHz).

[0024] In steps S330 to S360 , the processor 130 determines whether to reduce the sampling frequency of the ADC 120 according to the signal-to-noise ratio of the sampled data, and performs touch sensing according to the sampled data.

[0025] In step S330 , the ADC 120 samples the touch signal in the downlink signal to obtain sampled data, and the processor 130 obtains a signal-to-noise ratio of the sampled data.

[0026] In step S340, the processor 130 determines whether the signal-to-noise ratio of the sampled data is higher than the signal-to-noise ratio of the initial sampled data. The initial signal-to-noise ratio may be a single initial signal-to-noise ratio value or an initial signal-to-noise ratio range with an upper limit and a lower limit.

[0027] When the signal-to-noise ratio of the sampled data is higher than the signal-to-noise ratio range of the initial sampled data, step S340 is yes, indicating that the signal-to-noise ratio of the sampled data is higher than the requirement of the touch display system, so the process proceeds from step S340 to step S350, and the present embodiment reduces the sampling frequency of the ADC 120, for example, from the first sampling frequency value (1.6 MHz) to the second sampling frequency value (800 kHz). After reducing the sampling frequency of the ADC 120, the process returns from step S350 to step S330.

[0028] When the SNR of the sampled data is within the initial SNR range, it means that step S340 is no, and then the process proceeds to step S360, the ADC 120 does not adjust the sampling frequency and samples the downlink signal to provide sampled data, and the processor 130 performs touch sensing based on the sampled data.

[0029] In summary, the touch display device, touch display system and operation method thereof described in the embodiment of the present invention is that when the touch display device enters the low-frequency operation mode from the high-frequency operation mode, the processor in the touch display device first lowers the carrier frequency of the downlink signal of the active stylus through the uplink signal. The processor dynamically adjusts the sampling frequency of the ADC and determines whether the signal-to-noise ratio (SNR) in the sampled data provided by the ADC is higher than that required by the touch display system, thereby reducing the sampling frequency of the ADC or the number of sampling data to save the power consumption of the ADC and subsequent digital circuits during operation, thereby making the touch display device as a whole more power-saving.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A touch display device, characterized in that: include: A signal receiver, receiving a downlink signal from an active stylus, wherein the downlink signal includes an analog touch signal; an analog-to-digital converter, coupled to the signal receiver, and converting the analog touch signal into sampled data; a signal transmitter that sends an uplink signal to the active stylus, wherein a carrier frequency of the downlink signal provided by the active stylus is adjusted based on the uplink signal; as well as a processor, coupled to the analog-to-digital converter and the signal transmitter, Wherein, when the touch display device is in a low-frequency operation mode, the processor reduces the carrier frequency of the downlink signal provided by the active stylus through the signal transmitter and the uplink signal. The processor reduces the sampling frequency of the analog-to-digital converter and performs touch sensing according to the sampling data.

2. The touch display device according to claim 1, characterized in that: In the high-frequency operation mode of the touch display device, the processor sets the carrier frequency of the downlink signal provided by the active stylus to a first carrier frequency value through the signal transmitter and the uplink signal, and sets the sampling frequency of the analog-to-digital converter to a first sampling frequency value.

3. The touch display device according to claim 2, characterized in that: When the touch display device enters the low-frequency operating mode from the high-frequency operating mode, the processor adjusts the carrier frequency of the downlink signal provided by the active stylus from the first carrier frequency value to the second carrier frequency value through the signal transmitter and the uplink signal, wherein the first carrier frequency value is higher than the second carrier frequency value.

4. The touch display device according to claim 1, characterized in that: The processor dynamically determines whether to adjust the sampling frequency of the analog-to-digital converter according to the signal-to-noise ratio of the sampled data.

5. The touch display device according to claim 1, characterized in that: The processor reduces the data processing times of the analog-to-digital converter to reduce the sampling frequency of the analog-to-digital converter.

6. The touch display device according to claim 1, characterized in that: The processor comprises: A touch signal processor, coupled to the analog-to-digital converter, receives the sampled data sampled by the analog-to-digital converter; a signal-to-noise ratio adjuster coupled to the touch signal processor, calculating a signal-to-noise ratio of the sampled data according to the sampled data, and comparing the signal-to-noise ratio with an initial signal-to-noise ratio range to generate a comparison result; and The timing controller is coupled to the signal-to-noise ratio adjuster, and provides an uplink carrier frequency adjustment signal to the signal transmitter based on the comparison result, and adjusts the sampling frequency of the analog-to-digital converter.

7. The touch display device according to claim 1, characterized in that: The signal-to-noise ratio of the touch display device in the low-frequency operation mode is greater than or equal to the signal-to-noise ratio in the high-frequency operation mode.

8. A method for operating a touch display device, characterized in that: include: Obtaining a downlink signal from an active stylus, wherein the downlink signal comprises an analog touch signal; Converting the analog touch signal into sampled data based on an analog-to-digital converter, and performing touch sensing based on the sampled data; In a low frequency operation mode of the touch display device, the carrier frequency of the downlink signal provided by the active stylus is reduced by an uplink signal; and The sampling frequency of the analog-to-digital converter is reduced, and touch sensing is performed according to the sampled data.

9. The operating method according to claim 8, characterized in that: Also includes: In the high frequency operation mode of the touch display device, the carrier frequency of the downlink signal provided by the active stylus is set to a first carrier frequency value through the uplink signal, and the sampling frequency of the analog-to-digital converter is set to a first sampling frequency value.

10. The operating method according to claim 9, characterized in that: In the low-frequency operation mode of the touch display device, the step of reducing the carrier frequency of the downlink signal provided by the active stylus through the uplink signal includes: The carrier frequency of the downlink signal provided by the active stylus is adjusted from the first carrier frequency value to a second carrier frequency value through the uplink signal, wherein the first carrier frequency value is higher than the second carrier frequency value.

11. The operating method according to claim 8, characterized in that: The step of reducing the sampling frequency of the analog-to-digital converter comprises: Whether to adjust the sampling frequency of the analog-to-digital converter is dynamically determined according to the signal-to-noise ratio of the sampled data.

12. The operating method according to claim 8, characterized in that: The signal-to-noise ratio of the touch display device in the low-frequency operation mode is greater than or equal to the signal-to-noise ratio in the high-frequency operation mode.

13. The operating method according to claim 8, characterized in that: The data processing times of the analog-to-digital converter are reduced to lower the sampling frequency of the analog-to-digital converter.

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