Patent Application
20200402438
The present disclosure relates to the field of display, and more particularly, to a shift register and a method of driving the same, a gate driving circuit and a display apparatus.
Gate On Array (GOA) is a technology which integrates a gate driving circuit on a thin film transistor substrate. Each GOA unit serves as a shift register to sequentially transfer a scanning signal to a next GOA unit, to cause switches of the thin film transistor substrate to be turned on progressively, and complete input of data signals to pixel units.
Dual-VDD direct-current GOA architecture has been widely used in conventional GOA products due to its stable de-noising capability.
According to an embodiment of the present disclosure, there is provided a shift register. The shift register comprises:
In some embodiments, the control circuit comprises:
In some embodiments, the adjustment sub-circuit comprises:
In some embodiments, the first control signal terminal is coupled to the second power supply signal terminal, and the second control signal terminal is coupled to the first power supply signal terminal.
In some embodiments, the first control signal terminal and the second control signal terminal are coupled to each other.
In some embodiments, the first control sub-circuit comprises a third transistor and a fourth transistor, and the second control sub-circuit comprises a fifth transistor and a sixth transistor, wherein
In some embodiments, the first control sub-circuit comprises a third transistor, a fourth transistor, a seventh transistor, and an eighth transistor, and the second control sub-circuit comprises a fifth transistor, a sixth transistor, a ninth transistor and a tenth transistor, wherein
In some embodiments, the pull-down circuit comprises an eleventh transistor, a twelfth transistor, a thirteenth transistor, and a fourteenth transistor, wherein
In some embodiments, the pull-down circuit comprises an eleventh transistor, a twelfth transistor, a thirteenth transistor, a fourteenth transistor, a fifteenth transistor, and a sixteenth transistor, wherein
In some embodiments, the reset circuit comprises a seventeenth transistor and an eighteenth transistor, wherein,
In some embodiments, the reset circuit comprises a seventeenth transistor having a control electrode coupled to the first reset signal terminal, a first electrode coupled to the pull-up node, and a second electrode coupled to the reference signal terminal.
In some embodiments, the reset circuit comprises a seventeenth transistor, a nineteenth transistor, and a twentieth transistor, wherein
In some embodiments, the reset circuit comprises a seventeenth transistor and a nineteenth transistor, wherein
In some embodiments, the input circuit comprises a twenty-first transistor having a control electrode coupled to a signal input terminal, a first electrode coupled to the signal input terminal, and a second electrode coupled to the pull-up node.
In some embodiments, the output circuit comprises a twenty-second transistor and a capacitor, wherein
In some embodiments, the output circuit comprises a twenty-second transistor, a twenty-third transistor, and a capacitor, wherein
According to another embodiment of the present disclosure, there is provided a gate driving circuit, comprising a plurality of cascaded shift registers described above.
According to yet another embodiment of the present disclosure, there is provided a display apparatus comprising the gate driving circuit described above.
According to still another embodiment of the present disclosure, there is provided a method of driving the shift register described above, comprising:
In some embodiments, the first control signal received at the first control signal terminal is the second power supply signal received at the second power supply signal terminal, and the second control signal received at the second control signal terminal is the first power supply signal received at the first power supply signal terminal.
In some embodiments, the first control signal received at the first control signal terminal and the second control signal received at the second control signal terminal are both a third reset signal.
In some embodiments, an effective level of the third reset signal occurs before the start of each frame.
In some embodiments, an effective level of the third reset signal occurs in response to transition of the first power supply signal or the second power supply signal.
In order to make the purposes, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the embodiments described are a part of the embodiments of the present disclosure instead of all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without contributing any creative work are within the protection scope of the present disclosure. It should be illustrated that throughout the accompanying drawings, the same elements are represented by the same or similar reference signs. In the following description, some specific embodiments are for illustrative purposes only and are not to be construed as limiting the present disclosure, but merely examples of the embodiments of the present disclosure. The conventional structure or construction will be omitted when it may cause confusion with the understanding of the present disclosure. It should be illustrated that shapes and dimensions of components in the figures do not reflect true sizes and proportions, but only illustrate contents of the embodiments of the present disclosure.
Unless otherwise defined, technical terms or scientific terms used in the embodiments of the present disclosure should be of ordinary meanings to those skilled in the art. “First”, “second” and similar words used in the embodiments of the present disclosure do not represent any order, quantity or importance, but are merely used to distinguish between different constituent parts.
Furthermore, in the description of the embodiments of the present disclosure, the term “coupled with” or “coupled to” may mean that two components are directly coupled, or that two components are coupled via one or more other components. In addition, the two components may be connected or coupled by wire or wirelessly.
In addition, in the description of the embodiments of the present disclosure, terms “first level” and “second level” are only used to distinguish magnitudes of the two levels from each other. For example, description is made below by taking the “first level” being a low level and the “second level” being a high level as an example. It may be understood by those skilled in the art that the present disclosure is not limited thereto.
The transistors used in the embodiments of the present disclosure may each be a thin film transistor or a field effect transistor or other devices having the same characteristics. In one embodiment, the thin film transistors used in the embodiments of the present disclosure may be oxide semiconductor transistors. Since a source and a drain of the thin film transistor used herein are symmetrical, the source and the drain thereof may be interchanged. In the embodiments of the present disclosure, one of the source and the drain is referred to as a first electrode, and the other of the source and the drain is referred to as a second electrode. In the following example, N-type thin film transistors are taken as an example for description. It may be understood by those skilled in the art that the embodiments of the present disclosure may obviously be applied to a case of P-type thin film transistors.
The shift register and the method of driving the same, the gate driving circuit and the display apparatus according to the embodiments of the present disclosure may enable at least one of a first pull-down node and a second pull-down node to be reset to a level at a reference signal terminal more quickly than the conventional technology when a first power supply signal and a second power supply signal are switched, thereby preventing the slow charging of one of the first pull-down node and the second pull-down node from affecting the charging of a pull-up node.
As shown in
The shift register 100 may comprise an output circuit 102. The output circuit 102 may be coupled to a first signal output terminal OUT and a clock signal terminal CLK, and may be configured to transmit a clock signal received at the clock signal terminal CLK to the first signal output terminal OUT in response to a potential at the pull-up node PU.
The shift register 100 may comprise a control circuit 103. The control circuit 103 may be coupled to the pull-up node PU, a reference signal terminal VGL, a first power supply signal terminal VDDo, a second power supply signal terminal VDDe, a first control signal terminal CON1 and a second control signal terminal CON2, and may be configured to transmit a reference signal received at the reference signal terminal VGL to a first pull-down node PD1 and/or second pull-down node PD2 under control of a first control signal received at the first control signal terminal CON1 and a second control signal received at the second control signal terminal CON2 in response to the potential at the pull-up node PU.
In one embodiment, the reference signal received at the reference signal terminal VGL may always be maintained at a first level, a first power supply signal received at the first power supply signal terminal VDDo and a second power supply signal received at the second power supply signal terminal VDDe may be signals which are switched between the first level and a second level, for example, periodic pulse signals. This enables the first power supply signal to be at the first level and enables the second power supply signal to be at the second level during a first time period; and enables the first power supply signal to be at the second level and enables the second power supply signal to be at the first level during a second time period. The first power supply signal and the second power supply signal may have the same period and the same amplitude, but have opposite phases. The periods of the first power supply signal and the second power supply signal may be, for example, 2 seconds, or any suitable time. According to the present disclosure, switching of the two power supply signals means that while one power supply signal changes from the first level to the second level, the other power supply signal changes from the second level to the first level.
In one embodiment, the first control signal terminal CON1 may be coupled to the second power supply signal terminal VDDe, and the second control signal terminal CON2 may be coupled to the first power supply signal terminal VDDo. This enables the first control signal received at the first control signal terminal CON1 to be the second power supply signal received at the second power supply signal terminal VDDe, and enables the second control signal received at the second control signal terminal CON2 to be the first power supply signal received at the first power supply signal terminal VDDo.
In one embodiment, the first control signal terminal CON1 and the second control signal terminal CON2 may be coupled to receive the same signal (for example, a third reset signal), which enables the first control signal received at the first control signal terminal CON1 and the second control signal received at the second control signal terminal CON2 to be both the third reset signal. The third reset signal is used to reset the first pull-down node PD1 and the second pull-down node PD2, for example, pull down the first pull-down node PD1 and the second pull-down node PD2 to a low level. In some embodiments, an effective level of the third reset signal may occur before the start of each frame. In some other embodiments, the effective level of the third reset signal may occur in response to transition of the first power supply signal or the second power supply signal. For example, this enables the third reset signal to trigger the resetting of the first pull-down node PD1 and the second pull-down node PD2 before the start of each frame, or may trigger the resetting of the first pull-down node PD1 and the second pull-down node PD2 in response to the transition (at, for example, a rising edge or a falling edge) of the first power supply signal or the second power supply signal. That is, a period of the third reset signal may be the same as that of the first power supply signal or the second power supply signal, or may be the same as a period of the frame.
The shift register 100 may comprise a pull-down circuit 104. The pull-down circuit 104 may be coupled to the first pull-down node PD1 and the second pull-down node PD2, and may be configured to transmit the reference signal at the reference signal terminal VGL to the pull-up node PU in response to the potentials at the first pull-down node PD1 and the second pull-down node PD2.
The shift register 100 may comprise a reset circuit 105. The reset circuit 105 may be coupled to a first reset signal terminal RESET, the reference signal terminal VGL and the pull-up node PU, and may be configured to transmit the reference signal at the reference signal terminal VGL to the pull-up node PU under control of a first reset signal received at the first reset signal terminal RESET.
The shift register according to the present disclosure may enable at least one of the first pull-down node and the second pull-down node to be quickly reset to the level (for example, the first level) at the reference signal terminal when the first power supply signal and the second power supply signal are switched, thereby preventing the slow charging of a certain one of the first pull-down node and the second pull-down node from affecting the charging of the pull-up node.
Similarly to
As shown in
The first control sub-circuit 1031 is coupled to the first power supply signal terminal VDDo, the pull-up node PU and the first pull-down node PD1. The first control sub-circuit 1031 may control the potential at the first pull-down node PD1 based on the first power supply signal received at the first power supply signal terminal VDDo in response to the potential at the pull-up node PU.
The second control sub-circuit 1032 is coupled to the second power supply signal terminal VDDe, the pull-up node PU and the second pull-down node PD2. The second control sub-circuit 1032 may control the potential at the second pull-down node PD2 based on the second power supply signal received at the second power supply signal terminal VDDe in response to the potential at the pull-up node PU.
The adjustment sub-circuit 1033 is coupled to the first control signal terminal CON1, the second control signal terminal CON2, the first pull-down node PD1, the second pull-down node PD2, and the reference signal terminal VGL. The adjustment sub-circuit 1033 may transmit the reference signal received at the reference signal terminal VGL to the first pull-down node PD1 under control of the first control signal received at the first control signal terminal CON1, and transmit the reference signal received at the reference signal terminal VGL to the second pull-down node PD2 under control of the second control signal received at the second control signal terminal CON2.
As shown in
The shift register 200 may further comprise an output circuit 202. The output circuit 202 may comprise a twenty-second transistor M22 and a capacitor C1. The twenty-second transistor M22 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the clock signal terminal CLK, and a second electrode coupled to the first signal output terminal OUT. The capacitor C1 has a first terminal coupled to the pull-up node PU, and a second terminal coupled to the first signal output terminal OUT.
The shift register 200 may further comprise a control circuit 203. The control circuit 203 may comprise a first control sub-circuit, a second control sub-circuit, and an adjustment sub-circuit. The first control sub-circuit may comprise a third transistor M3 and a fourth transistor M4. The second control sub-circuit may comprise a fifth transistor M5 and a sixth transistor M6. The adjustment sub-circuit may comprise a first transistor M1 and a second transistor M2. The third transistor M3 has a control electrode coupled to the first power supply signal terminal VDDo, a first electrode coupled to the first power supply signal terminal VDDo, and a second electrode coupled to the first pull-down node PD1. The fifth transistor M5 has a control electrode coupled to the second power supply signal terminal VDDe, a first electrode coupled to the second power supply signal terminal VDDe, and a second electrode coupled to the second pull-down node PD2. The fourth transistor M4 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the first pull-down node PD1, and a second electrode coupled to the reference signal terminal VGL. The sixth transistor M6 has a control electrode coupled to the pull-up node PD1, a first electrode coupled to the second pull-down node PD2, and a second electrode coupled to the reference signal terminal VGL. The first transistor M1 has a control electrode coupled to the first control signal terminal CON1, a first electrode coupled to the first pull-down node PD1, and a second electrode coupled to the reference signal terminal VGL. The second transistor M2 has a control electrode coupled to the second control signal terminal CON2, a first electrode coupled to the second pull-down node PD2, and a second electrode coupled to the reference signal terminal VGL.
The shift register 200 may further comprise a pull-down circuit 204. The pull-down circuit 204 may comprise an eleventh transistor M11, a twelfth transistor M12, a thirteenth transistor M13, and a fourteenth transistor M14. The eleventh transistor M11 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The twelfth transistor M12 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The thirteenth transistor M13 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL. The fourteenth transistor M14 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL.
The shift register 200 may further comprise a reset circuit 205. The reset circuit 205 may comprise a seventeenth transistor M17 and an eighteenth transistor M18. The seventeenth transistor M17 has a control electrode coupled to the first reset signal terminal RESET, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The eighteenth transistor M18 has a control electrode coupled to the first reset signal terminal RESET, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL.
As shown in
The shift register 300 may further comprise an output circuit 302. The output circuit 302 may comprise a twenty-second transistor M22 and a capacitor C1. The twenty-second transistor M22 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the clock signal terminal CLK, and a second electrode coupled to the first signal output terminal OUT. The capacitor C1 has a first terminal coupled to the pull-up node PU, and a second terminal coupled to the first signal output terminal OUT.
The shift register 300 may further comprise a control circuit 303. The control circuit 303 may comprise a first control sub-circuit, a second control sub-circuit, and an adjustment sub-circuit. The first control sub-circuit may comprise a third transistor M3, a fourth transistor M4, a seventh transistor M7, and an eighth transistor M8. The second control sub-circuit may comprise a fifth transistor M5, a sixth transistor M6, a ninth transistor M9, and a tenth transistor M10. The adjustment sub-circuit may comprise a first transistor M1 and a second transistor M2. The third transistor M3 has a control electrode coupled to the first power supply signal terminal VDDo, a first electrode coupled to the first power supply signal terminal VDDo, and a second electrode coupled to a first electrode of the fourth transistor M4. The fifth transistor M5 has a control electrode coupled to the second power supply signal terminal VDDe, a first electrode coupled to the second power supply signal terminal VDDe, and a second electrode coupled to a first electrode of the sixth transistor M6. The fourth transistor M4 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second electrode of the third transistor M3, and a second electrode coupled to the reference signal terminal VGL. The sixth transistor M6 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second electrode of the fifth transistor M5, and a second electrode coupled to the reference signal terminal VGL. The first transistor M1 has a control electrode coupled to the first control signal terminal CON1, a first electrode coupled to the first pull-down node PD1, and a second electrode coupled to the reference signal terminal VGL. The second transistor M2 has a control electrode coupled to the second control signal terminal CON2, a first electrode coupled to the second pull-down node PD2, and a second electrode coupled to the reference signal terminal VGL. The seventh transistor M7 has a control electrode coupled to the second electrode of the third transistor M3, a first electrode coupled to the first power supply signal terminal VDDo, and a second electrode coupled to the first pull-down node PD1. The ninth transistor M9 has a control electrode coupled to the second electrode of the fifth transistor M5, a first electrode coupled to the second power supply signal terminal VDDe, and a second electrode coupled to the second pull-down node PD2. The eighth transistor M8 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the first pull-down node PD1, and a second electrode coupled to the reference signal terminal VGL. The tenth transistor M10 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second pull-down node PD2, and a second electrode coupled to the reference signal terminal VGL.
The shift register 300 may further comprise a pull-down circuit 304. The pull-down circuit 304 may comprise an eleventh transistor M11, a twelfth transistor M12, a thirteenth transistor M13, and a fourteenth transistor M14. The eleventh transistor M11 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The twelfth transistor M12 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The thirteenth transistor M13 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL. The fourteenth transistor M14 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL.
The shift register 300 may further comprise a reset circuit 305. The reset circuit 305 may comprise a seventeenth transistor M17. The seventeenth transistor M17 has a control electrode coupled to the first reset signal terminal RESET, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL.
As shown in
The shift register 400 may further comprise an output circuit 402. The output circuit 402 may comprise a twenty-second transistor M22 and a capacitor C1. The twenty-second transistor M22 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the clock signal terminal CLK, and a second electrode coupled to the first signal output terminal OUT. The capacitor C1 has a first terminal coupled to the pull-up node PU, and a second terminal coupled to the first signal output terminal OUT.
The shift register 400 may further comprise a control circuit 403. The control circuit 403 may comprise a first control sub-circuit, a second control sub-circuit, and an adjustment sub-circuit. The first control sub-circuit may comprise a third transistor M3, a fourth transistor M4, a seventh transistor M7, and an eighth transistor M8. The second control sub-circuit may comprise a fifth transistor M5, a sixth transistor M6, a ninth transistor M9, and a tenth transistor M10. The adjustment sub-circuit may comprise a first transistor M1 and a second transistor M2. The third transistor M3 has a control electrode coupled to the first power supply signal terminal VDDo, a first electrode coupled to the first power supply signal terminal VDDo, and a second electrode coupled to a first electrode of the fourth transistor M4. The fifth transistor M5 has a control electrode coupled to the second power supply signal terminal VDDe, a first electrode coupled to the second power supply signal terminal VDDe, and a second electrode coupled to a first electrode of the sixth transistor M6. The fourth transistor M4 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second electrode of the third transistor M3, and a second electrode coupled to the reference signal terminal VGL. The sixth transistor M6 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second electrode of the fifth transistor M5, and a second electrode coupled to the reference signal terminal VGL. The first transistor M1 has a control electrode coupled to the first control signal terminal CON1, a first electrode coupled to the first pull-down node PD1, and a second electrode coupled to the reference signal terminal VGL. The second transistor M2 has a control electrode coupled to the second control signal terminal CON2, a first electrode coupled to the second pull-down node PD2, and a second electrode coupled to the reference signal terminal VGL. The seventh transistor M7 has a control electrode coupled to the second electrode of the third transistor M3, a first electrode coupled to the first power supply signal terminal VDDo, and a second electrode coupled to the first pull-down node PD1. The ninth transistor M9 has a control electrode coupled to the second electrode of the fifth transistor M5, a first electrode coupled to the second power supply signal terminal VDDe, and a second electrode coupled to the second pull-down node PD2. The eighth transistor M8 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the first pull-down node PD1, and a second electrode coupled to the reference signal terminal VGL. The tenth transistor M10 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second pull-down node PD2, and a second electrode coupled to the reference signal terminal VGL.
The shift register 400 may further comprise a pull-down circuit 404. The pull-down circuit 404 may comprise an eleventh transistor M11, a twelfth transistor M12, a thirteenth transistor M13, and a fourteenth transistor M14. The eleventh transistor M11 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The twelfth transistor M12 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The thirteenth transistor M13 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL. The fourteenth transistor M14 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL.
The shift register 400 may further comprise a reset circuit 405. The reset circuit 405 may comprise a seventeenth transistor M17, a nineteenth transistor M19 and a twentieth transistor M20. The seventeenth transistor M17 has a control electrode coupled to the first reset signal terminal RESET, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The nineteenth transistor M19 has a control electrode coupled to a second reset signal terminal TRESET, a first electrode coupled to the pull-up node PU and a second electrode coupled to the reference signal terminal VGL. The twentieth transistor M20 has a control electrode coupled to the second reset signal terminal TRESET, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL. In the reset circuit 405, in order to enhance the de-noising of the pull-up node PU and the first signal output terminal OUT, the second reset signal at the second reset signal terminal TRESET is used for de-noising shift registers corresponding to all rows at the end of each frame. Differently from the second reset signal at the second reset signal terminal TRESET, the first reset signal at the first reset signal terminal RESET is used to pull down the pull-up node PU and the first signal output terminal OUT of the shift register after the output of the shift register is completed, so as to prevent display confusion due to the clock signal at the clock signal terminal CLK being continuously output to the first signal output terminal OUT.
As shown in
The shift register 500 may further comprise an output circuit 502. The output circuit 502 may comprise a twenty-second transistor M22, a twenty-third transistor M23, and a capacitor C1. The twenty-second transistor M22 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the clock signal terminal CLK, and a second electrode coupled to the first signal output terminal OUT. The twenty-third transistor M23 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the clock signal terminal CLK, and a second electrode coupled to the second signal output terminal OC. The capacitor C1 has a first terminal coupled to the pull-up node PU, and a second terminal coupled to the first signal output terminal OUT.
The shift register 500 may further comprise a control circuit 503. The control circuit 503 may comprise a first control sub-circuit, a second control sub-circuit, and an adjustment sub-circuit. The first control sub-circuit comprises a third transistor M3, a fourth transistor M4, a seventh transistor M7, and an eighth transistor M8. The second control sub-circuit comprises a fifth transistor M5, a sixth transistor M6, a ninth transistor M9, and a tenth transistor M10. The adjustment sub-circuit comprises a first transistor M1 and a second transistor M2. The third transistor M3 has a control electrode coupled to the first power supply signal terminal VDDo, a first electrode coupled to the first power supply signal terminal VDDo, and a second electrode coupled to a first electrode of the fourth transistor M4. The fifth transistor M5 has a control electrode coupled to the second power supply signal terminal VDDe, a first electrode coupled to the second power supply signal terminal VDDe, and a second electrode coupled to a first electrode of the sixth transistor M6. The fourth transistor M4 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second electrode of the third transistor M3, and a second electrode coupled to the reference signal terminal VGL. The sixth transistor M6 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second electrode of the fifth transistor M5, and a second electrode coupled to the reference signal terminal VGL. The first transistor M1 has a control electrode coupled to the first control signal terminal CON1, a first electrode coupled to the first pull-down node PD1, and a second electrode coupled to the reference signal terminal VGL. The second transistor M2 has a control electrode coupled to the second control signal terminal CON2, a first electrode coupled to the second pull-down node PD2, and a second electrode coupled to the reference signal terminal VGL. The seventh transistor M7 has a control electrode coupled to the second electrode of the third transistor M3, a first electrode coupled to the first power supply signal terminal VDDo, and a second electrode coupled to the first pull-down node PD1. The ninth transistor M9 has a control electrode coupled to the second electrode of the fifth transistor M5, a first electrode coupled to the second power supply signal terminal VDDe, and a second electrode coupled to the second pull-down node PD2. The eighth transistor M8 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the first pull-down node PD1, and a second electrode coupled to the reference signal terminal VGL. The tenth transistor M10 has a control electrode coupled to the pull-up node PU, a first electrode coupled to the second pull-down node PD2, and a second electrode coupled to the reference signal terminal VGL.
The shift register 500 may further comprise a pull-down circuit 504. The pull-down circuit 504 may comprise an eleventh transistor M11, a twelfth transistor M12, a thirteenth transistor M13, a fourteenth transistor M14, a fifteenth transistor M15, and a sixteenth transistor M16. The eleventh transistor M11 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The twelfth transistor M12 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The thirteenth transistor M13 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL. The fourteenth transistor M14 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the first signal output terminal OUT, and a second electrode coupled to the reference signal terminal VGL. The fifteenth transistor M15 has a control electrode coupled to the first pull-down node PD1, a first electrode coupled to the second signal output terminal OC, and a second electrode coupled to the reference signal terminal VGL. The sixteenth transistor M16 has a control electrode coupled to the second pull-down node PD2, a first electrode coupled to the second signal output terminal OC, and a second electrode coupled to the reference signal terminal VGL. In this embodiment, the output signal at the first signal output terminal OUT is only used to drive a display area, and the output signal at the second signal output terminal OC is used as an input signal of a next shift register unit.
The shift register 500 may further comprise a reset circuit 505. The reset circuit 505 may comprise a seventeenth transistor M17, and a nineteenth transistor M19. The seventeenth transistor M17 has a control electrode coupled to the first reset signal terminal RESET, a first electrode coupled to the pull-up node PU, and a second electrode coupled to the reference signal terminal VGL. The nineteenth transistor M19 has a control electrode coupled to a second reset signal terminal TRESET, a first electrode coupled to the pull-up node PU and a second electrode coupled to the reference signal terminal VGL. The first reset signal at the first reset signal terminal RESET is used to pull down the pull-up node PU and the first signal output terminal OUT in the shift register, to ensure normal output at the first signal output terminal OUT. Generally, during the operation of the shift register, since the clock signal terminal CLK is coupled to the pull-up node PU, the pull-up node PU generally has some noises. In order to prevent these noises from affecting an operation of a next frame, in general, the second reset signal at the second reset signal terminal TRESET may be used to perform general resetting after the end of the frame, for example, to reset all the shift registers of the gate driving circuit, thereby ensuring the stability of the shift registers.
In step S601, the input circuit transmits the input signal received at the signal input terminal to the pull-up node.
In step S602, in response to the potential at the pull-up node, the output circuit transmits the clock signal received at the clock signal terminal to the first signal output terminal.
In step S603, in response to the potential at the pull-up node, the control circuit transmits a first level of the reference signal to the first pull-down node and/or the second pull-down node under control of the first control signal and the second control signal. For example, in a case where the pull-up node is at the first level, when the first power supply signal received at the first power supply signal terminal and the second power supply signal received at the second power supply signal terminal are switched, at least one of the first control signal received at the first control signal terminal and the second control signal received at the second control signal terminal is at a second level, so that the control circuit transmits the first level of the reference signal received at the reference signal terminal to the first pull-down node and/or the second pull-down node.
In step S604, in response to the potentials at the first pull-down node and the second pull-down node, the pull-down circuit transmits the reference signal at the reference signal terminal to the pull-up node.
In step S605, the reset circuit transmits the reference signal at the reference signal terminal to the pull-up node under control of the first reset signal received at the first reset signal terminal.
In one embodiment, the first control signal received at the first control signal terminal is the second power supply signal received at the second power supply signal terminal, and the second control signal received at the second control signal terminal is the first power supply signal received at the first power supply signal terminal.
In another embodiment, the first control signal received at the first control signal terminal and the second control signal received at the second control signal terminal are a third reset signal. In some embodiments, an effective level of the third reset signal occurs before the start of each frame. In some other embodiments, the effective level of the third reset signal occurs in response to transition of the first power supply signal or the second power supply signal. This enables the third reset signal to trigger the resetting of at least one of the first pull-down node and the second pull-down node before each frame or to trigger the resetting of at least one of the first pull-down node and the second pull-down node in response to a rising edge or a falling edge of the first power supply signal or the second power supply signal.
With the method of driving a shift register according to the present disclosure, it may enable the potential at at least one of the first pull-down node and the second pull-down node to be the first level of the reference signal when the first power supply signal and the second power supply signal are switched, instead of changing to the first level of the reference signal after a period of time, thereby ensuring not affecting the charging of the pull-up node.
Next, an operation of the shift register according to the embodiment of the present disclosure will be described in detail with reference to
As shown in
During a time period t2, the second power supply signal at the second power supply signal terminal VDDe and the first control signal are maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo and the second control signal are maintained at a high level, the input signal INPUT is at a high level, the twenty-first transistor M21 is turned on, and the level at the pull-up node PU gradually rises from a low level through a pre-charging process. Since the pull-up node PU is at a high level, the twenty-second transistor M22 is turned on, and the clock signal at the clock signal terminal CLK is transmitted to the first signal output terminal OUT. In addition, since the pull-up node PU is at a high level, the fourth transistor M4 and the sixth transistor M6 are turned on, the low level at the reference signal terminal VGL is transmitted to the first pull-down node PD1 and the second pull-down node PD2 through the fourth transistor M4 and the sixth transistor M6 respectively, the first pull-down node PD1 becomes a low level, and the second pull-down node PD2 is still maintained at a low level.
During a time period t3, the second power supply signal at the second power supply signal terminal VDDe and the first control signal are maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo and the second control signal are maintained at a high level, the input signal INPUT is at a low level, the twenty-first transistor M21 is turned off, and the level at the pull-up node PU continues to rise through a bootstrapping process of the capacitor C1. Since the pull-up node PU is at a high level, the fourth transistor M4 and the sixth transistor M6 are still turned on, and the first pull-down node PD1 and the second pull-down node PD2 are still maintained at a low level.
During a time period t4, the second power supply signal at the second power supply signal terminal VDDe and the first control signal are maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo and the second control signal are maintained at a high level, and the first reset signal received at the first reset signal terminal RESET is at a high level. Since the first reset signal is at a high level, the seventeenth transistor M17 and the eighteenth transistor M18 are turned on, and the low level at the reference signal terminal VGL is transmitted to the pull-up node PU and the first signal output terminal OUT. Since the pull-up node PU is at a low level, the fourth transistor M4 and the sixth transistor M6 are turned off. At this time, since the first power supply signal is at a high level, the third transistor M3 is still turned on, and the high level of the first power supply signal is transmitted to the first pull-down node PD1. Since the second control signal is still at a high level, the second transistor M2 is still turned on. At this time, although the sixth transistor M6 is turned off, the low level at the reference signal terminal VGL may still be transmitted to the second pull-down node PD2. The second pull-down node PD2 is still maintained at a low level.
In general, a switching period of the first power supply signal and the second power supply signal (which are switched, for example, every 2 seconds) is much greater than that of a frame (which is switched, for example, every 16 milliseconds). In this way, a cycle of the multiple time periods t2, t3, and t4 elapses after a time period of t1, and then another cycle of the multiple time periods t2, t3, and t4 elapses after a time period of t1, and so on.
As shown in
During a time period t2, the second power supply signal at the second power supply signal terminal VDDe is maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo is maintained at a high level, the first control signal and the second control signal are at a low level, the input signal INPUT is at a high level, the twenty-first transistor M21 is turned on, and the level at the pull-up node PU gradually rises from a low level through a pre-charging process. Since the pull-up node PU is at a high level, the twenty-second transistor M22 is turned on, and the clock signal at the clock signal terminal CLK is transmitted to the first signal output terminal OUT. In addition, since the pull-up node PU is at a high level, the fourth transistor M4 and the sixth transistor M6 are turned on, the low level at the reference signal terminal VGL is transmitted to the first pull-down node PD1 and the second pull-down node PD2 through the fourth transistor M4 and the sixth transistor M6 respectively, the first pull-down node PD1 is maintained at a low level, and the second pull-down node PD2 is still maintained at a low level.
During a time period t3, the second power supply signal at the second power supply signal terminal VDDe is maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo is maintained at a high level, the first control signal and the second control signal are maintained at a low level, the input signal INPUT is at a low level, the twenty-first transistor M21 is turned off, and the level at the pull-up node PU continues to rise through a bootstrapping process of the capacitor C1. Since the pull-up node PU is at a high level, the fourth transistor M4 and the sixth transistor M6 are still turned on, and the first pull-down node PD1 and the second pull-down node PD2 are still maintained at a low level.
During a time period t4, the second power supply signal at the second power supply signal terminal VDDe is maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo is maintained at a high level, the first control signal and the second control signal are maintained at a low level, and the first reset signal received at the first reset signal terminal RESET is at a high level. Since the first reset signal is at a high level, the seventeenth transistor M17 and the eighteenth transistor M18 are turned on, and the low level at the reference signal terminal VGL is transmitted to the pull-up node PU. Since the pull-up node PU is at a low level, the fourth transistor M4 and the sixth transistor M6 are turned off. At this time, since the first power supply signal VDDo is at a high level and the first control signal is at a low level, the third transistor M3 is still turned on, and the first transistor M1 is turned off, so that the first pull-down node PD1 is pulled up to the high level at the first power supply signal terminal VDDo. Since the second power supply signal is at a low level and the second control signal is at a low level, both of the fifth transistor M5 and the second transistor M2 are turned off, and the second pull-down node PD2 is still maintained at a low level.
In this embodiment, the third reset signal is triggered by the rising edge or the falling edge of the first power supply signal or the second power supply signal. Therefore, the change of the third reset signal (i.e., the first control signal and the second control signal) corresponds to the change of the first power supply signal or the second power supply signal. Further, a switching period of the first power supply signal and the second power supply signal (which are switched, for example, every 2 seconds) is much greater than that of a frame (which is switched, for example, every 16 milliseconds). Therefore, this embodiment may be the same as that illustrated in
As shown in
During a time period t2, the second power supply signal at the second power supply signal terminal VDDe is maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo is maintained at a high level, the first control signal and the second control signal are at a low level, the input signal INPUT is at a high level, the twenty-first transistor M21 is turned on, and the level at the pull-up node PU gradually rises from a low level through a pre-charging process. Since the pull-up node PU is at a high level, the twenty-second transistor M22 is turned on, and the clock signal at the clock signal terminal CLK is transmitted to the first signal output terminal OUT. In addition, since the pull-up node PU is at a high level, the fourth transistor M4 and the sixth transistor M6 are turned on, the low level at the reference signal terminal VGL is transmitted to the first pull-down node PD1 and the second pull-down node PD2 through the fourth transistor M4 and the sixth transistor M6 respectively, the first pull-down node PD1 is maintained at a low level, and the second pull-down node PD2 is still maintained at a low level.
During a time period t3, the second power supply signal at the second power supply signal terminal VDDe is maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo is maintained at a high level, the first control signal and the second control signal are maintained at a low level, the input signal INPUT is at a low level, the twenty-first transistor M21 is turned off, and the level at the pull-up node PU continues to rise through a bootstrapping process of the capacitor C1. Since the pull-up node PU is at a high level, the fourth transistor M4 and the sixth transistor M6 are still turned on, and the first pull-down node PD1 and the second pull-down node PD2 are still maintained at a low level.
During a time period t4, the second power supply signal at the second power supply signal terminal VDDe is maintained at a low level, the first power supply signal at the first power supply signal terminal VDDo is maintained at a high level, the first control signal and the second control signal are maintained at a low level, and the first reset signal received at the first reset signal terminal RESET is at a high level. Since the first reset signal is at a high level, the seventeenth transistor M17 and the eighteenth transistor M18 are turned on, and the low level at the reference signal terminal VGL is transmitted to the pull-up node PU. Since the pull-up node PU is at a low level, the fourth transistor M4 and the sixth transistor M6 are turned off. At this time, since the first power supply signal VDDo is at a high level and the first control signal is at a low level, the third transistor M3 is still turned on, and the first transistor M1 is turned off, so that the first pull-down node PD1 is pulled up to the high level at the first power supply signal terminal VDDo. Since the second power supply signal is at a low level and the second control signal is at a low level, both of the fifth transistor M5 and the second transistor M2 are turned off, and the second pull-down node PD2 is still maintained at a low level.
In this embodiment, the effective level of the third reset signal occurs before the start of each frame. Therefore, the effective level of the third reset signal (i.e., the first control signal and the second control signal) arrives before an effective level of an input signal of a first row of shift register. Further, a switching period of the first power supply signal and the second power supply signal (which are switched, for example, every 2 seconds) is much greater than that of a frame (which is switched, for example, every 16 milliseconds). Therefore, in this embodiment, each switching between the first power supply signal and the second power supply signal may last for multiple cycles of the time period t1, t2, t3 and t4. Compared with the embodiment shown in
By comparing the timing diagram shown in
Based on the detailed description of
As shown in
With the gate driving circuit and the display apparatus according to the present disclosure, it may enable the potential at at least one of the first pull-down node and the second pull-down node to be the first level of the reference signal when the first power supply signal and the second power supply signal are switched, instead of changing to the first level of the reference signal after a period of time, thereby ensuring not affecting the charging of the pull-up node.
The specific embodiments described above further describe the purpose, technical solutions, and beneficial effects of the embodiments of the present disclosure in detail. It should be understood that the above description is only specific embodiments of the embodiments of the present disclosure, and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc., shall be contained in the scope of protection of the present disclosure without departing from the spirit and principles of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201910080262.6 | Jan 2019 | CN | national |
This application is a Section 371 National Application of International Application No. PCT/CN2019/127093, filed on Dec. 20, 2019, entitled “SHIFT REGISTER AND METHOD OF DRIVING THE SAME, GATE DRIVING CIRCUIT AND DISPLAY APPARATUS”, which published as WO 2020/155920 A1, on Aug. 6, 2020, which claims priority to the Chinese Patent Application No. 201910080262.6, filed on Jan. 28, 2019, the disclosures of which are incorporated herein by reference in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2019/127093 | 12/20/2019 | WO | 00 |
