Touch sensing device and power management method thereof

Abstract

A touch sensing device and a power management method thereof are provided. The touch sensing device includes a touch panel, a power supply and a capacitor circuit. The power supply is used to provide a driving voltage to the touch panel during a plurality of first sub-periods of an uplink signal transmitting period, and stop to provide the driving voltage to the touch pad during a plurality of second sub-periods of the uplink signal transmitting period. The capacitor circuit obtains a recycle energy according to discharge charges flowing from the touch panel during the second sub-periods of the uplink signal transmitting period.

Description

[Technical Field]

[0001] The present invention relates to a touch sensing device and a power management method thereof, and more particularly to a touch sensing device and a power management method thereof that can save power consumption. [Previous Technology]

[0002] In modern electronic devices, human-computer interaction via touch mechanisms has become an important function. In conventional touch sensing devices, the touch sensing device needs to generate uplink signals to communicate with the stylus. The uplink signal consists of multiple pulses and needs to be generated by repeatedly charging and discharging the touch panel. These repeated charging and discharging operations cause meaningless loss of electrical energy, resulting in energy waste. [Summary of the Invention]

[0003] The present invention provides a touch sensing device and a power management method thereof, which can effectively reduce the power consumption required by the touch sensing device.

[0004] The touch sensing device of the present invention includes a touch panel, a power supply, and a capacitor circuit. The power supply is coupled to the touch panel to provide a driving voltage to the touch panel during a plurality of first sub-periods of uplink signal transmission and to stop providing the driving voltage to the touch panel during a plurality of second sub-periods of uplink signal transmission. The capacitor circuit is coupled to the touch panel to recover electrical energy based on the discharge charge flowing out of the touch panel during the second sub-periods of uplink signal transmission.

[0005] The power management method of the present invention includes: providing a drive voltage to a touch panel by a power supply during a plurality of first sub-periods of uplink signal transmission, and ceasing to provide the drive voltage to the touch panel during a plurality of second sub-periods of uplink signal transmission. During the second sub-periods of uplink signal transmission, a capacitor circuit recovers electrical energy based on the discharge charge flowing out of the touch panel.

[0006] Based on the above, the touch sensing device of the present invention provides the generated discharge charge to the capacitor circuit when the voltage of the uplink signal is pulled low, and enables the capacitor circuit to recover electrical energy based on the discharge charge flowing out of the touch panel. In this way, the electrical energy of the discharge charge is not wasted, effectively saving the power consumption required by the touch sensing device.

Implementation Method

[0007] Please refer to FIG1, which illustrates a schematic diagram of a touch sensing device according to an embodiment of the present invention. The touch sensing device 100 includes a touch panel TP, a power supply 110, and a capacitor circuit 120. In this embodiment, the touch panel TP and the reference ground terminal GND can be regarded as an equivalent capacitor CTP. The touch panel TP is coupled to the power supply 110 through a transmission line W1, and the transmission line W1 has a transmission resistance RW. On the other hand, the capacitor circuit 120 is also coupled to the touch panel TP through the transmission line W1.

[0008] The touch panel TP in the touch sensing device 100 can sense the presence of the stylus by transmitting an uplink signal to the stylus during uplink signal transmission, and further communicate with the stylus. In this embodiment of the invention, during uplink signal transmission, the power supply 110 can provide a driving voltage to the touch panel TP during multiple first sub-periods. Furthermore, during multiple second sub-periods of the uplink signal transmission period, the power supply 110 can stop providing a driving voltage to the touch panel TP, and instead, the capacitor circuit 120 can receive the discharge charge flowing out of the touch panel TP through the transmission line W1, and recover electrical energy based on the received discharge charge.

[0009] In the above description, the plurality of first sub-periods occur alternately with the plurality of second sub-periods. In each first sub-period, the touch panel TP can receive an uplink signal as a first voltage, and in each second sub-period, the touch panel TP can receive and transmit an uplink signal as a second voltage, wherein the first voltage is greater than the second voltage.

[0010] As can be seen from the above description, in the touch sensing device 100 of this embodiment, during uplink signal transmission, the discharge charge generated when the uplink signal is pulled down from a first voltage to a second voltage can flow to the capacitor circuit, and energy can be recovered through the capacitor circuit. In this way, the power consumption of the touch sensing device 100 can be effectively reduced, achieving the effect of energy saving.

[0011] Please refer to FIG2, which illustrates a schematic diagram of the operation flow of the touch sensing device according to an embodiment of the present invention. In a frame (FR), the operation mode of the touch sensing device can be switched between multiple periods, including the uplink signal transmission period (UPL), the idle period (IDL), the downlink signal reception period (DNL), and the touch sensing period (TD). Specifically, during the first uplink signal transmission period (UPL) in FIG2, the touch panel can transmit the uplink signal US1; during the downlink signal reception period (DNL), the touch panel can receive the downlink reception signal DS1; during the touch sensing period (TD), the touch panel can transmit the touch sensing drive signal TDS1; and during the second uplink signal transmission period (UPL) in FIG2, the touch panel can transmit the uplink signal US1 again.

[0012] In this embodiment, the uplink signal US1 can be a pulse width modulation signal, transitioning between a first voltage V1 and a second voltage V2. The downlink receive signal DS1 can be a DC voltage signal. The touch sensing drive signal TDS1 can be a pulse signal with a fixed duty cycle. Furthermore, during the idle period IDL, the voltage on the touch panel can be maintained equal to a DC voltage, for example, equal to the ground voltage.

[0013] Please refer to Figures 2 and 3 simultaneously. Figure 3 is an enlarged schematic diagram of the uplink signal in the embodiment of Figure 2. The uplink signal transmission period UPL includes multiple first sub-periods T1 and multiple second sub-periods T2. Figure 3 will only show a portion of the first sub-periods T1 and a portion of the second sub-periods T2 for illustration. The first sub-periods T1 and the second sub-periods T2 are interleaved. In the first sub-period T1, the uplink signal US1 is equal to a relatively high first voltage V1. In the second sub-period T2, the uplink signal US1 is equal to a relatively low second voltage V2.

[0014] In the first sub-period T1, the touch panel can receive a driving voltage to charge, thereby raising the voltage of the uplink signal US1 to a first voltage V1. In the second sub-period T2, the touch panel can stop receiving the driving voltage and begin discharging to lower the voltage of the uplink signal US1 to a second voltage V2.

[0015] Please refer to FIG4 below, which illustrates a schematic diagram of a touch sensing device according to another embodiment of the present invention. The touch sensing device 400 includes a touch panel TP, a power supply 410, a capacitor circuit 420, and a charge transfer circuit 430. The power supply 410 and the capacitor circuit 420 are coupled to the touch panel TP via a transmission line W1. The power supply 410 includes a power supply switch SW1, wherein the power supply switch SW1 is coupled between a drive power supply 411 and the touch panel TP. The drive power supply 411 is used to generate a drive voltage VD. The power supply switch SW1 is turned on during each of the first sub-periods of the uplink signal transmission period, and the drive voltage VD generated by the drive power supply 411 can be transmitted to the touch panel TP via the transmission line W1 to charge the equivalent capacitance CTP on the touch panel TP.

[0016] Furthermore, during each of the second sub-periods of the uplink signal transmission, the power supply switch SW1 can be turned off. The power supply 410 also stops supplying the drive voltage VD to the touch panel TP.

[0017] In this embodiment, the capacitor circuit 420 is, for example, a charge pump circuit, and the plurality of capacitors C1 to C3 in the capacitor circuit 420 can be flying capacitors coupled to the charge pump circuit. During each of the second sub-periods of the uplink signal transmission, the equivalent capacitance CTP discharges and generates a discharge current Idis. The discharge current Idis can flow to the capacitor circuit 420, and the discharge current Idis charges at least one of the capacitors C1 to C3 in the capacitor circuit 420 to recover electrical energy.

[0018] In this embodiment, the capacitor circuit 420 can generate an offset power supply VSH. The capacitor circuit 420 can generate a charging current Id1 from the recovered electrical energy stored in the capacitor circuit 420 according to the offset power supply VSH to charge the energy storage capacitor CPM on the charge transfer circuit 430.

[0019] In some embodiments of the present invention, the voltage generated by the offset power supply VSH can be dynamically adjusted.

[0020] In this embodiment, the charge transfer circuit 430 can receive the stored electrical energy in the energy storage capacitor CPM and use it as operating power for the application circuits in the touch sensing device 100 to perform other functions. In this way, the recovered electrical energy stored in the capacitor circuit 420 can be recycled and reused, improving the efficiency of power use.

[0021] It is worth noting that the charge transfer circuit 430 in this embodiment of the invention can be a power management circuit. It can allocate the stored energy in the energy storage capacitor CPM to any circuit of the electronic device corresponding to the touch sensing device, and provide auxiliary power to the corresponding circuit.

[0022] It is worth noting that in this embodiment, the capacitor circuit 420 is a voltage pump circuit, which can be used to provide the voltage required for the display panel of the electronic device to display images. Therefore, when the display panel of the electronic device enters a dark screen state, the voltage generating circuit 430 will be idle and will not perform any operation. In this case, the capacitors C1 to C3 on the capacitor circuit 420 can be unused and can be used as a medium for storing and recovering electrical energy. That is to say, in this embodiment of the invention, the capacitors C1 to C3 on the capacitor circuit 420 can be constructed using existing components, without the need for additional components, which can reduce the required circuit cost.

[0023] It is worth mentioning that in other embodiments of the present invention, other capacitors can be provided in the capacitor circuit 420, or idle capacitors inside the capacitor circuit 420 can be used as a medium for storing and recovering electrical energy.

[0024] Please refer to FIG5A, which illustrates a schematic diagram of a touch sensing device according to another embodiment of the present invention. The touch sensing device 501 includes a touch panel TP, a power supply 410, and a charge transfer circuit 430. In this embodiment, the charge transfer circuit 430 can serve as a capacitor circuit and is coupled to the touch panel TP and the power supply 410. Continuing from the embodiment of FIG4, during each of the second sub-periods of the uplink signal transmission period, the discharge charge generated by the discharge of the equivalent capacitor CTP can directly charge the energy storage capacitor CPM on the charge transfer circuit 430, thereby recovering electrical energy. The charge transfer circuit 430 can be coupled to an application circuit (not shown) and provides the recovered electrical energy as part of the operating power required for the operation of the application circuit.

[0025] Referring again to FIG5B, FIG5B illustrates a schematic diagram of a touch sensing device according to another embodiment of the present invention. The touch sensing device 502 includes a touch panel TP, a power supply 410, a capacitor circuit 420, and an application circuit 510. In this embodiment, the capacitor circuit 420 can provide a charging current to charge the application circuit 510 based on the stored recycled electrical energy, thereby providing part of the operating power required for the application circuit 510 to operate.

[0026] Please refer to FIG6 below, which illustrates a flowchart of a power management method according to an embodiment of the present invention. The power management method of FIG6 is applicable to a touch sensing device. In step S610, the power supply provides a driving voltage to the touch panel during a plurality of first sub-periods of uplink signal transmission, and stops providing the driving voltage to the touch panel during a plurality of second sub-periods of uplink signal transmission. Furthermore, in step S620, the capacitor circuit can recover electrical energy based on the discharge charge flowing out of the touch panel during the second sub-period of uplink signal transmission.

[0027] The implementation details of the above steps have been described in detail in the aforementioned embodiments, and will not be repeated here.

[0028] In summary, the touch sensing device of the present invention provides a capacitor circuit to generate recovered electrical energy based on the discharge charge when the touch panel generates a discharge current during uplink signal transmission. Accordingly, the electrical energy consumed during the discharge operation of the touch panel is not wasted, and the power consumption required by the touch sensing device can be effectively reduced, achieving energy saving. [Simplified Explanation of the Diagram]

[0029] Figure 1 is a schematic diagram of a touch sensing device according to an embodiment of the present invention. Figure 2 is a schematic diagram of the operation flow of the touch sensing device according to an embodiment of the present invention. Figure 3 is an enlarged schematic diagram of the uplink signal of the embodiment of Figure 2. Figure 4 is a schematic diagram of a touch sensing device according to another embodiment of the present invention. Figures 5A and 5B are schematic diagrams of touch sensing devices according to different embodiments of the present invention. Figure 6 is a flowchart of a power management method according to an embodiment of the present invention.

Claims

1. A touch sensing device, comprising: One touch panel; A power supply, coupled to the touch panel, for providing a driving voltage to the touch panel during a plurality of first sub-periods of an uplink signal transmission, and ceasing to provide the driving voltage to the touch panel during a plurality of second sub-periods of the uplink signal transmission; and a capacitor circuit, coupled to the touch panel, for recovering electrical energy based on a discharge charge flowing out of the touch panel during the second sub-periods of the uplink signal transmission.

2. The touch sensing device as claimed in claim 1, wherein the first sub-periods are interleaved with the second sub-periods.

3. The touch sensing device as claimed in claim 1, wherein the touch panel generates an uplink signal as a first voltage during each of the first sub-periods and pulls the uplink signal down to a second voltage during each of the second sub-periods.

4. The touch sensing device as claimed in claim 1, wherein the power supply comprises: A switch is coupled between a power supply and the touch panel, wherein the switch is turned on during each of the first sub-periods to provide the drive voltage generated by the power supply to the touch panel, and wherein the switch is turned off during each of the second sub-periods.

5. The touch sensing device as claimed in claim 1, wherein the capacitive circuit is coupled to a charge transfer circuit, the touch sensing device further comprising: An application circuit is coupled to the charge transfer circuit to receive the recovered electrical energy as operating power.

6. The touch sensing device as claimed in claim 1, wherein the capacitor circuit is a charge transfer circuit that receives the discharged charge to obtain the recovered electrical energy, and the touch sensing device further comprises: An application circuit is coupled to the charge transfer circuit to receive the recovered electrical energy as operating power.

7. The touch sensing device as claimed in claim 1, wherein the capacitor circuit is further coupled to: an offset power supply for superimposing a voltage on the capacitor circuit to generate an adjusted voltage, and providing the adjusted voltage to charge an energy storage capacitor.

8. The touch sensing device as described in claim 7, further comprising: An application circuit, coupled to the capacitor circuit, receives the stored electrical energy of the energy storage capacitor as part of the operating electrical energy.

9. The touch sensing device as claimed in claim 1, wherein the capacitor circuit provides at least one capacitor as a medium for storing the recovered electrical energy, the at least one capacitor being an external or internal idle capacitor.

10. The touch sensing device as claimed in claim 9, wherein the at least one capacitor is an idle capacitor when the display panel corresponding to the touch sensing device enters a dark screen state.

11. A power management method applicable to a touch sensing device, comprising: A power supply provides a driving voltage to a touch panel during a plurality of first sub-periods of an uplink signal transmission, and stops providing the driving voltage to the touch panel during a plurality of second sub-periods of the uplink signal transmission; and a capacitor circuit recovers electrical energy based on a discharge charge flowing out of the touch panel during the second sub-periods of the uplink signal transmission.

12. The power management method as claimed in claim 11, wherein the first sub-periods are interleaved with the second sub-periods.

13. The power management method as described in claim 11 further includes: The touch panel generates an uplink signal of a first voltage during each of the first sub-periods, and pulls the uplink signal down to a second voltage during each of the second sub-periods.

14. The power management method of claim 11, wherein the steps of causing the power supply to provide the driving voltage to the touch panel during the first sub-periods of the uplink signal transmission period and stopping the supply of the driving voltage to the touch panel during the second sub-periods of the uplink signal transmission period include: A switch is installed between a power supply and the touch panel; The switch is turned on during each of the first sub-periods so that the drive voltage generated by the drive power supply is provided to the touch panel; and the switch is turned off during each of the second sub-periods.

15. The power management method as described in claim 11 further includes: This capacitor circuit is coupled to a charge transfer circuit; The touch sensing device further includes an application circuit, which is coupled to the charge transfer circuit to receive the recovered electrical energy as operating power.

16. The power management method as described in claim 11 further includes: Make the capacitor circuit a charge transfer circuit; make the charge transfer circuit receive the recovered electrical energy; The touch sensing device further includes an application circuit that receives the recovered electrical energy as operating power.

17. The power management method as described in claim 11 further includes: An offset power supply is provided to be superimposed on the voltage on the capacitor circuit to generate an adjusted voltage; And to provide the adjusted voltage to charge an energy storage capacitor.

18. The power management method as described in claim 17 further includes: The stored energy of the energy storage capacitor is supplied to an application circuit as part of the operating power of the application circuit.

19. The power management method as described in claim 11, further comprising: The capacitor circuit provides at least one capacitor as a medium for storing the recovered electrical energy, wherein the at least one capacitor is an external capacitor or an internal idle capacitor.

20. The power management method as described in claim 19 further includes: When the display panel corresponding to the touch sensing device enters a dark screen state, the at least one capacitor is an idle capacitor.

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