Display apparatus and control method thereof

Abstract

A display apparatus and a control method thereof are provided. The display device comprises a plurality of display area substrates, a common mode voltage generator and at least one alternating current voltage generator. Display area substrates are arranged in a display panel, wherein each display area substrate receives a gate line signal, a source line signal, and a common mode voltage. The common-mode voltage generator is coupled to the display area substrates and is used for generating common-mode voltage to each display area substrate. The AC voltage generator is coupled to the common-mode voltage generator and is used for generating an adjusting voltage to the common-mode voltage according to driving current information of a plurality of source drivers of the display device, and the adjusting voltage has an AC voltage level.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a display apparatus and a control method thereof, and more particularly, to a display apparatus capable of reducing radiation on a display panel caused by gate line signals and source line signals and a control method thereof. BACKGROUND

[0002] Reference is made to Figure 1A and Figure 1B wherein Figure 1A a schematic diagram of a display apparatus of the related art is shown, Figure 1B a waveform diagram of a display apparatus is shown. Figure 1A The display apparatus 100 includes a display panel 110 and a driver integrated circuit (IC) 120. A plurality of display area substrates 111~115 are arranged in the display panel 110. The display area substrates 111 and 114 arranged in the same row commonly receive the same gate line signal G1; the display area substrate 113 receives the gate line signal G2; the display area substrates 112 and 115 arranged in the same row commonly receive the same gate line signal G3. On the other hand, the display area substrates 111 and 112 arranged in the same column commonly receive the same source line signal SC1; the display area substrate 113 receives the source line signal SC2; the display area substrates 114 and 115 arranged in the same column commonly receive the source line signal SC3.

[0003] The driver IC 120 provides a plurality of common mode voltages RX to each of the display area substrates 111~115. In each of the display area substrates 111~115, there is a parasitic capacitance between any two terminals that receive the common mode voltage RX, receive each of the gate line signals G1~G3, and receive each of the source line signals SC1~SC3. That is, referring to Figure 1B , although the driver IC 120 provides the common mode voltage RX_OP having a DC (direct current) voltage level, the common mode voltage RX received by each of the display area substrates 111~115 can be interfered by a transition state of the gate line signal Gx and the source line signal SCx. Here, the gate line signal Gx can be one of the gate line signals G1~G3, and the source line signal SCx can be one of the source line signals SC1~SC3. As such, a positive pulse can be generated on the common mode voltage RX via a rising state of the gate line signal Gx or the source line signal SCx, and a negative pulse can be generated on the common mode voltage RX via a falling state of the gate line signal Gx or the source line signal SCx. Radiation on the display panel 110 can occur from the rising edge and the falling edge, and electromagnetic interference (EMI) can occur on the display apparatus 100. SUMMARY

[0004] The disclosure provides a plurality of display apparatuses and control methods thereof for reducing radiation on a display panel caused by gate line signals and source line signals.

[0005] A display device includes multiple display area substrates, a common-mode voltage generator, and at least one AC voltage generator. The display area substrates are arranged in a display panel, wherein each display area substrate receives a gate line signal, a source line signal, and a common-mode voltage. The common-mode voltage generator is coupled to the display area substrates and is configured to generate a common-mode voltage for each display area substrate. The AC voltage generator is coupled to the common-mode voltage generator and is configured to generate an adjustment voltage to the common-mode voltage based on drive current information from multiple source drivers of the display device, wherein the adjustment voltage has an AC voltage level.

[0006] A display device includes multiple display area substrates, a common-mode voltage generator, and at least one AC voltage generator. The display area substrates are arranged in a display panel, wherein each display area substrate receives a gate line signal, a source line signal, and a common-mode voltage. The common-mode voltage generator is coupled to the display area substrates and is configured to generate a common-mode voltage for each display area substrate. The AC voltage generator is coupled to the common-mode voltage generator and is configured to generate an adjustment voltage for the common-mode voltage based on a transition state of a corresponding gate line signal, wherein the adjustment voltage has an AC voltage level.

[0007] A control method for a display device includes: arranging multiple display area substrates in a display panel, wherein each display area substrate receives a gate line signal, a source line signal, and a common-mode voltage; providing a common-mode voltage generator for generating a common-mode voltage to each display area substrate; and providing at least one AC voltage generator for generating an adjustment voltage to the common-mode voltage via the AC voltage generator based on driving current information of multiple source drivers of the display device or based on a transition state of a corresponding gate line signal, wherein the adjustment voltage has an AC voltage level.

[0008] Based on the above, the display device of the present disclosure provides an AC voltage generator to generate an adjustment voltage based on the drive current information of multiple source drivers, and to compensate for the common-mode voltage by applying the adjustment voltage to the common-mode voltage. In this way, radiation from the display area of ​​the display device caused by source and gate line signals can be reduced, and EMI on the display device can be correspondingly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A A schematic diagram showing a display device in the related art.

[0010] Figure 1B Show Figure 1A The waveform diagram of the display device.

[0011] Figure 2A A schematic diagram illustrating a display device according to an embodiment of the present disclosure.

[0012] Figure 2B a waveform diagram of the display device according to an embodiment of the present disclosure. Figure 2A a waveform diagram of the display device according to an embodiment of the present disclosure.

[0013] Figure 2C a schematic diagram of the AC voltage generator 220 according to an embodiment of the present disclosure. Figure 2A a schematic diagram of the AC voltage generator 220 according to an embodiment of the present disclosure.

[0014] Figure 3A a schematic diagram of the display device according to another embodiment of the present disclosure.

[0015] Figure 3B a waveform diagram of the display device 300 according to an embodiment of the present disclosure. Figure 3A a waveform diagram of the display device according to an embodiment of the present disclosure.

[0016] Figure 4 a waveform diagram of the display device according to another embodiment of the present disclosure.

[0017] Figure 5 a schematic diagram of the layout of the display device according to an embodiment of the present disclosure.

[0018] Figure 6 a flowchart of the control method of the display device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] Reference is made to Figure 2A , which shows a schematic diagram of a display device according to an embodiment of the present disclosure. The display device 200 includes a common-mode voltage generator 210 and an AC voltage generator 220. In the present embodiment, the display device 200 further includes a display panel 110 as shown in Figure 1A , and a plurality of source drivers SD1-SD3. The common-mode voltage generator 210 generates a common-mode voltage RX_OP having a direct current voltage level. An output terminal of the AC voltage generator 220 is coupled to an output terminal of the common-mode voltage generator 210. The AC voltage generator 220 generates an adjustment voltage ACRX and transmits the adjustment voltage ACRX to the common-mode voltage RX_OP. The adjustment voltage ACRX can be combined with the common-mode voltage RX_OP to generate common-mode voltages RX1-RX3, and each of the common-mode voltages RX1-RX3 can be transmitted to each display area substrate 111-115 as shown in Figure 1A .

[0020] In this embodiment, the AC voltage generator 220 generates the adjustment voltage ACRX based on driving current information from the source drivers SD1-SD3 of the display device 200. The driving current information includes source current information Id1 and drain current information Id2. In this embodiment, the source current information Id1 and drain current information Id2 can be obtained from the source drivers SD1-SD3. The AC voltage generator 220 can obtain the source current information Id1 and drain current information Id2 from the current transmitter of each source driver SD1-SD3.

[0021] In detail, let's take source driver SD3 as an example. Source driver SD3 includes a current conveyor 241. Current conveyor 241 may include transistors T1 and T2. Transistor T1 functions as a pull-up transistor and is coupled between a power supply terminal VCC and the output terminal of source driver SD3. Transistor T2 functions as a pull-down transistor and is coupled between a reference ground terminal GND and the output terminal of source driver SD3. AC voltage generator 220 is coupled to the control terminals of transistors T1 and T2 and obtains source current information Id1 and drain current information Id2 based on the drive signals of transistors T1 and T2.

[0022] In practice, the AC voltage generator 220 is coupled to the current conveyors of the source drivers SD1-SD3. The AC voltage generator 220 can obtain source current information Id1 based on the driving signals of the pull-up transistors of the current conveyors, and obtain drain current information Id2 based on the driving signals of the pull-down transistors of the current conveyors.

[0023] Please refer to Figure 2A and Figure 2B ,in Figure 2B Showing the Figure 2A Waveform diagram of the display device of the embodiment. Figure 2A In this example, source line signal SC1 is used as an example. When source line signal SC1 transitions from a low voltage level to a high voltage level, the pull-up transistor of the current conveyor of source driver SD1 may be turned on. AC voltage generator 220 may receive source current information Id1 and generate a negative pulse PS1 on regulated voltage ACRX during time period TP1. Conversely, when source line signal SC1 transitions from a high voltage level to a low voltage level, the pull-down transistor of the current conveyor of source driver SD1 may be turned on. AC voltage generator 220 may receive drain current information Id2 and generate a positive pulse PS2 on regulated voltage ACRX during time period TP2.

[0024] As can be seen, AC voltage generator 220 provides a regulated voltage ACRX having negative pulses PS1 and positive pulses PS2, which is combined with common-mode voltage RX_OP generated by common-mode voltage generator 210 to generate common-mode voltage RX1 received by each display region substrate. In this way, interference from common-mode voltage RX_OP can be compensated for by the negative pulses PS1 and positive pulses PS2 of regulated voltage ACRX. This reduces radiation from the display panel and EMI from display device 200.

[0025] It should be noted that in some embodiments, since the AC voltage generator 220 is coupled to a plurality of source drivers SD1-SD3, the AC voltage generator 220 can determine whether to generate a positive pulse PS2 or a negative pulse PS1 on the regulated voltage ACRX by comparing the drain current information Id2 with the source current information Id1. Specifically, if the drain current information Id2 is greater than the source current information Id1, the AC voltage generator 220 may generate a positive pulse PS2 on the regulated voltage ACRX. If the drain current information Id2 is less than the source current information Id1, the AC voltage generator 220 may generate a negative pulse PS1 on the regulated voltage ACRX. Furthermore, if the drain current information Id2 is equal to the source current information Id1, the AC voltage generator 220 may set the regulated voltage ACRX to maintain a constant voltage level.

[0026] Please refer to Figure 2C , which shows that according to the present disclosure Figure 2A FIG2 is a schematic diagram of an AC voltage generator 220 according to an embodiment of the present invention. The AC voltage generator 220 may include current sources IS1 and IS2. The current source IS1 is coupled between a power supply terminal VCC and an output terminal of the AC voltage generator 220. The current source IS2 is coupled between the output terminal of the AC voltage generator 220 and a reference ground terminal GND. The current source IS1 can be controlled by drain current information Id2 and is used to provide a source current to the output terminal of the AC voltage generator 220. The current source IS2 can be controlled by source current information Id1 and is used to draw a drain current from the output terminal of the AC voltage generator 220. The output terminal of the AC voltage generator 220 is used to generate a regulated voltage ACRX.

[0027] In this embodiment, if the source current generated by current source IS1 is greater than the drain current generated by current source IS2, the voltage level of the regulated voltage ACRX may be pulled up to generate a positive pulse on the regulated voltage ACRX. If the source current generated by current source IS1 is less than the drain current generated by current source IS2, the voltage level of the regulated voltage ACRX may be pulled down to generate a negative pulse on the regulated voltage ACRX. Furthermore, if the source current generated by current source IS1 is equal to the drain current generated by current source IS2, the voltage level of the regulated voltage ACRX is maintained at a constant level.

[0028] Please refer toFigure 3A FIG. 3 shows a schematic diagram of a display device according to another embodiment of the present disclosure. The display device 300 includes a common-mode voltage generator 310, an alternating voltage generator 320, source drivers SD1-SD3, an LV (low voltage) conversion register 340, a logic circuit 350, and a plurality of switches 331-333. In this embodiment, the display device 300 can further include a display panel 110 as shown in Figure 1A The common-mode voltage generator 310 generates a common-mode voltage RX_OP having a direct current voltage level. The output terminal of the alternating voltage generator 320 is coupled to the output terminal of the common-mode voltage generator 310. The alternating voltage generator 320 generates an adjustment voltage ACRX and transmits the adjustment voltage ACRX to the common-mode voltage RX_OP. The adjustment voltage ACRX can be combined with the common-mode voltage RX_OP to generate common-mode voltages RX1-RX3, and each of the common-mode voltages RX1-RX3 can be transmitted to each of the display area substrates 111-115 as shown in Figure 1A FIG. 1, respectively, through the switches 331-333.

[0029] On the other hand, the input terminals of the source drivers SD1-SD3 are coupled to the LV conversion register 340. The LV conversion register 340 is used to store a plurality of display data corresponding to the source drivers SD1-SD3, convert each of the display data to each of the source drivers SD1-SD3, and output each of the display data to the corresponding source driver SD1-SD3.

[0030] Unlike the display device 200 in Figure 2A , the alternating voltage generator 320 of this embodiment is coupled to the logic circuit 350. The logic circuit 350 is coupled to the LV conversion register 340. The logic circuit 350 receives a plurality of input data (display data) of the source drivers SD1-SD3. The logic circuit 350 sums the input data to obtain summed data, and calculates the difference of the summed data at different time periods to obtain driving current information.

[0031] Please refer to Figure 3A and Figure 3B , wherein Figure 3B shows Figure 3AA waveform diagram of the display device 300 is shown in the embodiment. The logic circuit 350 can sum the input data of the source drivers SD1~SD3 to obtain summed data, and calculate the difference of the summed data to obtain the drive current information IDI. The difference of the drive current information IDI can be +n corresponding to the rising state of the source line signal SCx. In addition, the difference of the drive current information IDI can be -n corresponding to the falling state of the source line signal SCx, where n is a positive number. Here, the source line signal SCx can be a combined signal of the source line signals outputted by the source drivers SD1~SD3. In the embodiment, the difference of the drive current information IDI is a digital code.

[0032] In response to the drive current information IDI, the AC voltage generator 320 can generate the adjustment voltage ACRX according to the difference of the drive current information IDI. The AC voltage generator 320 can generate the adjustment voltage ACRX with a negative pulse corresponding to the drive current information IDI with the difference of +n, and generate the adjustment voltage ACRX with a positive pulse corresponding to the drive current information IDI with the difference of -n. If the difference of the drive current information IDI is 0, the AC voltage generator 320 keeps the voltage level of the adjustment voltage ACRX unchanged.

[0033] Please refer to Figure 4 , which shows a waveform diagram of a display device according to another embodiment of the present disclosure. In Figure 4 , the AC voltage generator of the display device can be coupled to the gate line drivers of the display device. The AC voltage generator can generate the adjustment voltage ACRX according to the transition state of each gate line signal Gx of the display device. The AC voltage generator can generate the adjustment voltage ACRX with a negative pulse PS1 corresponding to the rising edge of the gate line signal Gx, and generate the adjustment voltage ACRX with a positive pulse PS2 corresponding to the falling edge of the gate line signal Gx. Via applying the adjustment voltage ACRX on the common mode voltage generated by the common mode voltage generator of the display device, the common mode voltage RX received by each display area substrate can be compensated. The compensated common mode voltage RX can be substantially maintained at a constant voltage level, and the radiation on the display device can be reduced.

[0034] The circuit structure regarding the embodiment can refer to FIG. 2. In the embodiment, the AC voltage generator 220 can be further coupled to the gate line drivers of the display device 200. The AC voltage generator 220 can obtain the transition state of each gate line driver via receiving the drive current information of the gate line drivers. The drive current information of the gate line drivers can be obtained via the same scheme as the drive current information of the source drivers in the embodiment, which will not be described herein again. Figure 2A and Figure 3A The scheme of obtaining the drive current information of the source drivers in the embodiment is the same as that of the gate line drivers, which will not be described herein again.

[0035] Please refer to Figure 5Fig. 5 shows a schematic diagram illustrating a layout of a display device according to an embodiment of the present disclosure. In this embodiment, a plurality of AC voltage generators 521-52N can be arranged in the display device 500. The output terminals of the AC voltage generators 521-52N are coupled to the output terminal of the common mode voltage generator 510. The common mode voltage generator 510 is controlled by an enable signal EN. The AC voltage generators 521-52N can be separately arranged in the display device 500. In this embodiment, each of the AC voltage generators 521-52N can be independently controlled. In addition, the number of the AC voltage generators 521-52N can be determined by a designer according to the actual application state of the display device 500, which is not limited here. Furthermore, in some embodiments, a first portion of the AC voltage generators 521-52N can be configured to generate the adjustment voltage according to the driving current information of the source drivers, while a second portion of the AC voltage generators 521-52N can be configured to generate the adjustment voltage according to the driving current information of the gate drivers. In other embodiments, each of the AC voltage generators 521-52N can be configured to generate the adjustment voltage according to the driving current information of the source drivers and the gate drivers.

[0036] Referring to Figure 6 Fig. 6 shows a flowchart illustrating a control method of a display device according to an embodiment of the present disclosure. In step S610, a plurality of display area substrates are arranged in a display panel, wherein each of the display area substrates receives a gate line signal, a source line signal and a common mode voltage. In step S620, a common mode voltage generator is provided to generate the common mode voltage to each of the display area substrates. In step S630, at least one AC voltage generator is provided to generate an adjustment voltage to the common mode voltage via the AC voltage generator according to the driving current information of a plurality of source drivers of the display device or according to the transition state of a corresponding gate line signal, wherein the adjustment voltage has an AC voltage level.

[0037] The detailed operations of steps S610-S630 have been described in the above embodiments, which will not be repeated here.

[0038] In summary, the display device of the present disclosure provides an AC voltage generator to generate an adjustment voltage according to the driving current information of the source drivers and / or the gate drivers. By applying the adjustment voltage to the common mode voltage, the peak voltage on the common mode voltage can be compensated, and the radiation on the display device can be accordingly reduced. In this way, the EMI tolerance of the display device can be enhanced.

Claims

1. A display apparatus, comprising: a plurality of display area substrates arranged in a display panel, wherein each of the display area substrates receives a gate line signal, a source line signal and a common voltage; a common voltage generator coupled to the display area substrates for generating the common voltage to each of the display area substrates; and at least one alternating voltage generator coupled to the common voltage generator for generating an adjustment voltage to the common voltage according to driving current information of a plurality of source drivers of the display apparatus, wherein the adjustment voltage has an alternating voltage level.

2. The display apparatus of claim 1, wherein the alternating voltage generator generates a positive pulse on the adjustment voltage when a sink current information of the driving current information is greater than a source current information of the driving current information, and generates a negative pulse on the adjustment voltage when the sink current information is less than the source current information.

3. The display apparatus of claim 2, wherein the alternating voltage generator comprises: a first current source coupled between a power supply terminal and an output terminal of the alternating voltage generator, and providing a source current to the output terminal of the alternating voltage generator according to the sink current information; and a second current source coupled between a reference ground terminal and the output terminal of the alternating voltage generator, and sinking a sink current from the output terminal of the alternating voltage generator according to the source current information.

4. The display apparatus of claim 2, wherein the alternating voltage generator is further coupled to a plurality of current transmitters of the source drivers, and acquires the source current information and the sink current information according to driving signals of the current transmitters.

5. The display apparatus of claim 4, wherein each of the current transmitters comprises: a first transistor coupled between a power supply terminal and an output terminal of each of the current transmitters, and controlled by a first driving signal; and a second transistor coupled between a reference ground terminal and the output terminal of each of the current transmitters, and controlled by a second driving signal, wherein the alternating voltage generator acquires the source current information according to the first driving signals of all of the source drivers, and acquires the sink current information according to the second driving signals of all of the source drivers.

6. The display apparatus of claim 1, further comprising: a logic circuit coupled to the source drivers, wherein the logic circuit receives a plurality of input data of the source drivers, calculates a sum of the input data to obtain summed data, and calculates a difference of the summed data in different time periods to obtain the driving current information.

7. The display apparatus of claim 6, wherein the logic circuit subtracts a second summed data in a second time period from a first summed data in a first time period to calculate the difference, wherein the first time period is earlier than the second time period. ​ ​ ​ 8. The display device of claim 7 , wherein if the difference is a negative value, the AC voltage generator generates a negative pulse on the adjusted voltage according to the driving current information, and if the difference is a positive value, the AC voltage generator generates a positive pulse on the adjusted voltage according to the driving current information. 9 . The display device as claimed in claim 1 , wherein the AC voltage generator further generates the adjustment voltage according to a transient state of a corresponding gate line signal.

10. The display device of claim 9, wherein the AC voltage generator generates a negative pulse on the adjustment voltage if the corresponding gate line signal transitions from a first voltage to a second voltage, wherein the first voltage is less than the second voltage. 11 . The display device of claim 10 , wherein the AC voltage generator generates a positive pulse on the adjustment voltage if the corresponding gate line signal transitions from the first voltage to the second voltage.

12. A display device comprising: A plurality of display area substrates are arranged in the display panel, wherein each of the display area substrates receives a gate line signal, a source line signal and a common mode voltage; a common mode voltage generator coupled to the display area substrate for generating the common mode voltage to each of the display area substrates; as well as At least one AC voltage generator is coupled to the common mode voltage generator and is configured to generate an adjustment voltage to the common mode voltage according to a transition state of a corresponding gate line signal, wherein the adjustment voltage has an AC voltage level.

13. A method for controlling a display device, comprising: Arranging a plurality of display area substrates in the display panel, wherein each of the display area substrates receives a gate line signal, a source line signal and a common mode voltage; Providing a common mode voltage generator for generating the common mode voltage to each of the display area substrates; as well as At least one AC voltage generator is provided for generating an adjustment voltage to the common mode voltage according to driving current information of multiple source drivers of the display device or according to a transition state of a corresponding gate line signal via the AC voltage generator, wherein the adjustment voltage has an AC voltage level.

14. The control method according to claim 13, further comprising: When the drain current information of the driving current information is greater than the source current information of the driving current information, generating a positive pulse on the adjustment voltage via the AC voltage generator; as well as When the drain current information is less than the source current information, a negative pulse is generated on the adjustment voltage.

15. The control method according to claim 14, further comprising: coupling the AC voltage generator to a plurality of current conveyors of the source driver; as well as The source current information and the drain current information are acquired according to a driving signal of the current conveyor.

16. The control method according to claim 13, further comprising: receiving a plurality of input data of the source driver via a logic circuit; as well as The sum of the input data is calculated to obtain sum data, and the difference of the sum data in different time periods is calculated through the logic circuit to obtain the driving current information.

17. The control method of claim 16, further comprising: subtracting second summation data of a second time period from first summation data of a first time period to calculate the difference, wherein the first time period is earlier than the second time period.

18. The control method of claim 17, further comprising: generating a negative pulse on the adjustment voltage via the AC voltage generator based on the drive current information if the difference is negative; and generating a positive pulse on the adjustment voltage via the AC voltage generator based on the drive current information if the difference is positive.

19. The control method of claim 13, further comprising: generating a negative pulse on the adjustment voltage via the AC voltage generator if the corresponding gate line signal transitions from a first voltage to a second voltage, wherein the first voltage is less than the second voltage.

20. The control method of claim 19, further comprising: generating a positive pulse on the adjustment voltage via the AC voltage generator if the corresponding gate line signal transitions from the second voltage to the first voltage. ​

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