The present disclosure relates to the field of display technologies and, in particular, to a source driving circuit, a driving method, and a display device.
Display panels usually display pictures in a progressive scanning manner. During a display period of one frame, a control chip is required to progressively scan all pixel units in a display area.
As a frame rate of the display panel increases, a charging time for each row of sub-pixel units becomes shorter. Meeting a preset charging requirement for each pixel unit has become a key issue in a design of the display panel.
It should be noted that the information disclosed in the Background above is only for enhancing the understanding of the background of the present disclosure and thus, may include information that does not constitute prior art known to those of ordinary skill in the art.
According to an aspect of the present disclosure, there is provided a source driving circuit including a buffer amplifier configured to generate a driving signal from an original driving signal. The buffer amplifier includes a first amplifier and a second amplifier. A high-level terminal of the first amplifier is coupled to a first power signal terminal, a low-level terminal of the first amplifier is coupled to a second power signal terminal, and an output terminal of the first amplifier is configured to output a positive polarity driving signal. A high-level terminal of the second amplifier is coupled to a third power signal terminal, a low-level terminal of the second amplifier is coupled to a fourth power signal terminal, and an output terminal of the second amplifier is configured to output a negative polarity driving signal. A voltage of the second power signal terminal is less than a voltage of the third power signal terminal.
In an exemplary embodiment of the present disclosure, a voltage of the first power signal terminal is a voltage of an analog power signal; a voltage of the fourth power signal terminal is a ground voltage; the voltage of the second power signal terminal is less than a voltage of a half-value analog power signal; and the voltage of the third power signal terminal is greater than the voltage of a half-value analog power signal.
In an exemplary embodiment of the present disclosure, the buffer amplifier further includes a switching assembly; the low-level terminal of the first amplifier is coupled to either the second power signal terminal or a fifth power signal terminal through the switching assembly; the high-level terminal of the second amplifier is coupled to either the third power signal terminal or the fifth power signal terminal through the switching assembly; the switching assembly is configured to couple the low-level terminal of the first amplifier to the second power signal terminal and couple the high-level terminal of the second amplifier to the third power signal terminal in a first driving state, and to couple the low-level terminal of the first amplifier to the fifth power signal terminal and couple the high-level terminal of the second amplifier to the fifth power signal terminal in a second driving state.
In an exemplary embodiment of the present disclosure, a voltage of the fifth power signal terminal is equal to the voltage of the half-value analog power signal.
In an exemplary embodiment of the present disclosure, the source driving circuit further includes a detection circuit, an arithmetic circuit, and a control circuit. The detection circuit is configured to detect a potential of an effective pulse signal for each row in the original driving signal in real time; the arithmetic circuit is coupled to the detection circuit and is configured to calculate a potential difference between the effective pulse signal for a current row and the effective pulse signal for a previous row in real time based on the potential of the effective pulse signal for each row; the control circuit is coupled to the arithmetic circuit and the switching assembly and is configured to send a control signal to the switching assembly based on the potential difference between the effective pulse signal for current row and the effective pulse signal for previous row to control a driving state of the switching assembly; wherein, when the potential difference between the effective pulse signal for the current row and the effective pulse signal for the previous row is greater than a preset value, the switching assembly is controlled to operate in the first driving state during at least a portion of a period of the current row; and when the potential difference between the effective pulse signal for the current row and the effective pulse signal for the previous row is less than the preset value, the switching assembly is controlled to operate in the second driving state during a drive period of the current row.
In an exemplary embodiment of the present disclosure, the switching assembly includes a first switching unit, a second switching unit, a third switching unit, and a fourth switching unit. The first switching unit is coupled to the low-level terminal of the first amplifier, the second power signal terminal, and a first control terminal, and is configured to connect the low-level terminal of the first amplifier with the second power signal terminal in response to a signal of the first control terminal; the second switching unit is coupled to the high-level terminal of the second amplifier, the third power signal terminal, and the first control terminal, and is configured to connect the high-level terminal of the second amplifier with the third power signal terminal in response to the signal of the first control terminal; the third switching unit is coupled to the low-level terminal of the first amplifier, the fifth power signal terminal, and a second control terminal, and is configured to connect the low-level terminal of the first amplifier with the fifth power signal terminal in response to a signal of the second control terminal; and the fourth switching unit is coupled to the high-level terminal of the second amplifier, the fifth power signal terminal, and the second control terminal, and is configured to connect the high-level terminal of the second amplifier with the fifth power signal terminal in response to the signal of the second control terminal.
In an exemplary embodiment of the present disclosure, the first switching unit includes a first switching transistor having a first terminal coupled to the low-level terminal of the first amplifier, a second terminal coupled to the second power signal terminal, and a control terminal coupled to the first control terminal;
the second switching unit includes a second switching transistor having a first terminal coupled to the high-level terminal of the second amplifier, a second terminal coupled to the third power signal terminal, and a control terminal coupled to the first control terminal;
the third switching unit includes a third switching transistor having a first terminal coupled to the low-level terminal of the first amplifier, a second terminal coupled to the fifth power signal terminal, and a control terminal coupled to the second control terminal; and
the fourth switching unit includes a fourth switching transistor having a first terminal coupled to the high-level terminal of the second amplifier, a second terminal coupled to the fifth power signal terminal, and a control terminal coupled to the second control terminal.
In an exemplary embodiment of the present disclosure, the first switching transistor, the second switching transistor, the third switching transistor, and the fourth switching transistor are N-type transistors or P-type transistors.
According to another aspect of the present disclosure, there is provided a driving method of a source driving circuit, for driving the source driving circuit described above, and the method includes:
outputting the positive polarity driving signal by the first amplifier in a positive drive phase;
outputting the negative polarity driving signal by the second amplifier in a negative drive phase.
In an exemplary embodiment of the present disclosure, the source driving circuit further includes a switching assembly, and the method further includes:
by the switching assembly:
connecting the low-level terminal of the first amplifier with the second power signal terminal and connecting the high-level terminal of the second amplifier with the third power signal terminal in a first driving state; and
connecting the low-level terminal of the first amplifier with a fifth power signal terminal and connecting the high-level terminal of the second amplifier with the fifth power signal terminal in a second driving state.
In an exemplary embodiment of the present disclosure, the source driving circuit further includes a detection circuit, an arithmetic circuit, and a control circuit, and the method further includes:
detecting by the detection circuit a potential of an effective pulse signal for each row in the original driving signal in real time;
calculating by the arithmetic circuit a potential difference between the effective pulse signal for a current row and the effective pulse signal for a previous row in real time based on the potential of the effective pulse signal for each row;
sending by the control circuit a control signal to the switching assembly based on the potential difference between the effective pulse signal for the current row and the effective pulse signal for the previous row to control a driving state of the switching assembly;
wherein, when the potential difference between the effective pulse signal for the current row and the effective pulse signal for the previous row is greater than a preset value, the switching assembly is controlled to operate in the first driving state during at least a portion of a period of the current row; and
when the potential difference between the effective pulse signal for the current row and the effective pulse signal for the previous row is less than the preset value, the switching assembly is controlled to operate in the second driving state during a driving period of the current row.
According to another aspect of the present disclosure, there is provided a display device including the source driving circuit described above.
It should be noted that the above general description and the following detailed description are merely exemplary and explanatory and should not be construed as limiting the present disclosure.
The accompanying drawings, which are incorporated into and constitute a part of the specification, show embodiments consistent with the present disclosure, and are used to explain the principles of the present disclosure together with the specification. It is understood that the drawings in the following description show only some of the embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art based on these drawings without any creative effort.
Exemplary embodiments will now be described more fully with reference to the drawings. However, the exemplary embodiments can be implemented in various forms, and should not be construed as being limited to the examples set forth herein; rather, these embodiments are provided to make the present disclosure more comprehensive and complete, and fully convey the ideas of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings indicate the same or similar structures, and thus the detailed description thereof will be omitted.
Although relative terms are used in this specification, such as “upper” and “lower”, to describe the relative relationship between one component and another component shown in the drawings, these terms are used in this specification only for convenience, for example, in the direction shown in the examples of the drawings. It can be understood that if the device shown is turned upside down, the component described as “upper” will become the “lower” component. Other relative terms, such as “high”, “low”, “top”, “bottom”, “left”, “right”, etc., have similar meanings. When a structure is said to be “on” another structure, it may indicate that the structure is integrally formed on the other structure, or that the structure is “directly” provided on the other structure, or that the structure is provided on the other structure “indirectly” through another structure.
The terms “a”, “an”, “the”, and “said” are used to indicate the presence of one or more elements/components, etc.; the terms “include/including” and “have/having” are used to represent an open-ended sense of inclusion and mean that there may be additional elements/components, etc., in addition to the listed elements/components, etc.
In the related art, as the frame rate of the display panel increases, a charging time for each row of sub-pixel units becomes increasingly shorter, and due to a voltage drop caused by a resistance and a parasitic capacitance of data lines, charging voltages for the sub-pixel units on a side away from the source driving circuit cannot meet the preset requirement, which finally causes a uneven display of the display panel.
In view of the above technical problems, and based on that a reference power supply for the source driving circuit is provided by an analog power signal AVDD, the voltage of the driving signal can be increased by increasing the voltage of the analog power signal AVDD in the related art to solve the above technical problems. However, after the analog power signal AVDD is increased, a potential difference between effective pulses for adjacent rows in the driving signal will be increased. For example, in an example where the first row displays at 255 gray-scale and the second row displays at 0 gray-scale, when the voltage of the analog power signal AVDD is 18V, the voltage of the effective pulse for the first row is 16V and the voltage of the effective pulse for the second row is 8V; and when the voltage of the analog power signal AVDD is 20V, the voltage of the effective pulse for the first row is 18V and the voltage of the effective pulse for the second row is 9V. Understandably, a former voltage difference (8V) of the effective pulses for adjacent rows is smaller than a latter voltage difference (9V) of the effective pulses for adjacent rows.
Since it also takes time for the buffer amplifier to convert the signal, and the greater the voltage difference between the pulse signals for the adjacent rows in the original driving signal, the longer the time required for the buffer amplifier to convert the signal. Therefore, the increase in the voltage of the analog power signal AVDD will cause an increase in the time for the source driving circuit to output the driving signal. As a result, the data signal cannot reach the preset voltage within a time interval between the adjacent effective pulses.
In view of the above problems, an exemplary embodiment of the present disclosure provides a source driving circuit.
A voltage of the first power signal terminal AVDD can be the voltage of the analog power signal AVDD, the voltage of the second power signal terminal HAVDD− can be less than a voltage of a half-value analog power signal HAVDD, the voltage of the third power signal terminal HAVDD+ can be greater than the voltage of the half-value analog power signal HAVDD, and a voltage of the fourth power signal terminal can be a voltage of the ground terminal. The voltage of the second power signal terminal HAVDD− is in between the voltage of the first power signal terminal AVDD and the voltage of the fourth power signal terminal VSS; the voltage of the third power signal terminal HAVDD+ is in between the voltage of the first power signal terminal AVDD and the voltage of the fourth power signal terminal VSS.
The present disclosure provides a source driving circuit. On one hand, the source driving circuit provided by the present disclosure can increase the voltage of the output driving signal by increasing the voltage of the analog power signal AVDD, thereby solving the technical problem of insufficient charging of the sub-pixel units; on the other hand, the source driving circuit provided by the present disclosure increases a changing rate of the output voltage of the amplifier and reduces the generation time of the driving signal by increasing the voltage difference between the high-level terminal and the low-level terminal of each of the first amplifier and the second amplifier, thereby solving the technical problem of excessive generation time of the driving signal caused by the increase of the analog power signal AVDD. In addition, in the positive polarity driving and the negative polarity driving, gamma voltages at 0 gray-scale correspond to the voltages of the second power signal terminal HAVDD− and the third power signal terminal HAVDD+, respectively, and by setting the level of the second power signal terminal to be lower than the level of the third power signal terminal, the voltage at 0 gray-scale in the positive polarity driving can be reduced and the voltage at 0 gray-scale in the negative polarity driving can be increased. That is, a target voltage drop is increased when the data signal transitions to 0 gray-scale, thereby increasing the rate of the data signal voltage drop and thus further reducing the time in which the data signal transitions to 0 gray-scale.
In this exemplary embodiment, the source driving circuit is provided with two power signal terminals: the second power signal terminal HAVDD− and the third power signal terminal HAVDD+. Although such arrangement can improve the display effect, it also increases power consumption of the source driving circuit. When the voltage difference between the effective pulses for the adjacent rows in the driving signal is small, the above-mentioned technical problem that “the data signal cannot reach the preset voltage within the time interval between the adjacent effective pulses” does not exist.
In this exemplary embodiment,
In an exemplary embodiment, as shown in
The present exemplary embodiment also provides a driving method for a source driving circuit, which is used for driving the source driving circuit described above.
in step S1, outputting the positive polarity driving signal by the first amplifier in a positive driving phase; and
in step S2, outputting the negative polarity driving signal by the second amplifier in a negative driving phase.
In this exemplary embodiment, the source driving circuit further includes a switching assembly, and the method further includes:
by the switching assembly:
connecting the low-level terminal of the first amplifier with the second power signal terminal and connecting the high-level terminal of the second amplifier with the third power signal terminal in the first driving state; and
connecting the low-level terminal of the first amplifier with the fifth power signal terminal and connecting the high-level terminal of the second amplifier with the fifth power signal terminal in the second driving state.
In this exemplary embodiment, the source driving circuit further includes a detection circuit, an arithmetic circuit, and a control circuit, and the method further includes:
detecting by the detection circuit a potential of effective pulse signal for each row in the original driving signal in real time;
calculating by the arithmetic circuit a potential difference between the effective pulse signal for a current row and the effective pulse signal for a previous row in real time based on the potential of the effective pulse signal for each row; and
sending by the control circuit a control signal to the switching assembly based on the potential difference between the effective pulse signal for the current row and the effective pulse signal for the previous row to control the driving state of the switching assembly,
wherein when the potential difference between the effective pulse signal for the current row and the effective pulse signal for the previous row is greater than a preset value, the switching assembly is controlled to operate in the first driving state during at least a portion of a period of the current row, and
when the potential difference between the effective pulse signal for the current row and the effective pulse signal for the previous row is less than the preset value, the switching assembly is controlled to operate in the second driving state during a driving period of the current row.
The driving method for the source driving circuit provided by the present disclosure has the same technical features and operating principles as those for the source driving circuit described above, which have been described in detail and will not be repeated here.
The exemplary embodiment of the present disclosure also provides a display device including the source driving circuit described above.
The display device provided by the present disclosure has the same technical features and operating principles as those for the source driving circuit described above, which have been described in detail and will not be repeated here.
The display device can include, but is not limited to, a display device such as a TV, a mobile phone, a VR display device, and a laptop.
The present disclosure provides a source driving circuit, a driving method, and a display device. The source driving circuit includes a buffer amplifier configured to generate a driving signal from an original driving signal. The buffer amplifier includes a first amplifier and a second amplifier. A high-level terminal of the first amplifier is coupled to a first power signal terminal, a low-level terminal of the first amplifier is coupled to a second power signal terminal, and an output terminal of the first amplifier is configured to output a positive polarity driving signal; a high-level terminal of the second amplifier is coupled to a third power signal terminal, a low-level terminal of the second amplifier is coupled to a fourth power signal terminal, and an output terminal of the second amplifier is configured to output a negative polarity driving signal. A voltage of the second power signal terminal is less than a voltage of the third power signal terminal. On one hand, the source driving circuit provided by the present disclosure can increase the voltage of the output driving signal by increasing the voltage of the analog power signal AVDD, thereby solving the technical problem of insufficient charging of the sub-pixel units. On the other hand, the source driving circuit provided by the present disclosure increases a changing rate of the output voltage of the amplifier and reduces the generation time of the driving signal by increasing the voltage difference between the high-level terminals and the low-level terminals of the first amplifier and the second amplifier, thereby solving the technical problem of excessive generation time of the driving signal due to the increase of the analog power signal AVDD. In addition, by setting the level of the second power signal terminal to be lower than the level of the third power signal terminal, a positive driving voltage at 0 gray-scale can be reduced and a negative driving voltage at 0 gray-scale can be increased. That is, a target voltage drop is increased when the data signal transitions to the 0 gray-scale, thereby increasing the rate of the data signal voltage drop and thus further reducing time in which the data signal transitions to the 0 gray-scale.
Other embodiments of the present disclosure will be apparent to those skilled in the art after considering the specification and practicing the technical solutions disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present disclosure which follow the general principles of the present disclosure and include common knowledge or conventional technical measures in the art that are not disclosed in the present disclosure. The specification and embodiments are merely illustrative, and the real scope and spirit of the present disclosure is defined by the appended claims.
It should be understood that the present disclosure is not limited to the precise structures that have been described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.
This application is a national phase application under 35 U.S.C. § 371 of International Patent Application No. PCT/CN2019/107364 filed on Sep. 23, 2019, the contents of which are incorporated by reference in their entirety herein.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2019/107364 | 9/23/2019 | WO | 00 |