This application is a National Phase of PCT Patent Application No. PCT/CN2020/087748 having International filing date of Apr. 29, 2020, which claims the benefit of priority of Chinese Patent Application No. 202010257397.8 filed on Apr. 3, 2020. The contents of the above applications are all incorporated by reference as if fully set forth herein in their entirety.
The present invention relates to the technical field of display, a protection system for GOA circuit and a liquid crystal display panel in particular.
Traditional liquid crystal display (LCD) devices include source drivers, gate drivers and an LCD panel, and the gate drivers are disposed outside the LCD panel. In prior art, the gate drivers have been disposed on the LCD panel, that is, the gate driver on array (GOA) technique. The GOA technique makes use of existing thin film transistor LCD panel array fabrication processes to fabricate the driving signal circuit of the gate scan line on the array substrate to realize progressive scanning of the gate. When a clock signal and an initial trigger signal STV, generated by the control panel, are transmitted to the GOA unit, the GOA unit will generate a scan signal to the pixel unit in the pixel array area, and the source driver will output the grayscale voltage to the pixel unit in the pixel array area at the same time to make the LCD panel display normally.
As shown in
Therefore, technical problems exist in the prior art, wherein if even one short circuit occurs between a low potential signal VSSQ/VSSG and a high-voltage signal, it will cause a massive surge in electric flow and can affect the normal operation of the entire GOA circuit, leading to an abnormal display, and can even cause the display panel to burn out. This problem needs to be solved.
The present application provides a protection system and a liquid crystal display panel for GOA circuit which can solve the technical problems, exist in the prior art, about the large current, abnormal operation of the whole GOA circuit, display abnormally and LCD panel burn-out caused by the low potential signal VSSQ/VSSG short-circuited with the high-potential signal in any one of the GOA units of multiple cascade GOA units in the GOA circuit of the LCD panel.
In order to solve above problems, the technical solutions provided by the present application are as follows:
An embodiment of the present application provides a protection system for a gate on array (GOA) circuit. The protection system includes a detection circuit which is connected to the GOA circuit, and is configured to generate a driving signal in response to a low potential signal of the GOA circuit; and a switching circuit which is signally-connected to an initial trigger signal, the detection circuit and the GOA circuit, the switching circuit is configured to transmit the initial trigger signal to the GOA circuit according to the driving signal.
Wherein, upon a low voltage level of the low potential signal, the switching circuit is turned on to conduct the initial trigger signal to the GOA circuit, and upon a high voltage level of the low potential signal, the switching circuit is turned off so that the GOA circuit does not conduct the initial trigger signal.
A preferred embodiment according to the present application, the detection circuit includes a first comparator and an inverter, the low potential signal includes a first low potential signal; an input terminal of the first comparator is signally-connected to the first low potential signal; an output terminal of the first comparator is connected to an input terminal of the inverter; an output terminal of the inverter is connected to a control terminal of the switching circuit.
A preferred embodiment according to the present application, the low potential signal further includes a second low potential signal; the detection circuit further includes a second comparator; an input terminal of the second comparator is signally-connected to the second low potential signal; both of an output terminal of the second comparator and an output terminal of the first comparator are connected to an input terminal of the inverter.
A preferred embodiment according to the present application, the switching circuit includes a switching thin film transistor (TFT); a drain of the switching TFT is signally-connected to the initial trigger signal; a source of the switching TFT is connected to the GOA circuit; a gate of the switching TFT is signally-connected to the driving signal.
A preferred embodiment according to the present application, the first comparator includes a first TFT, a second TFT, a third TFT, and a fourth TFT, arranged in a first row; a fifth TFT, a sixth TFT, a seventh TFT and an eighth TFT, arranged in a second row; wherein sources of the first TFT, the second TFT, the third TFT, and the fourth TFT are electrically connected to 28V voltage to form a high potential circuit loop, drains of the fifth TFT, the sixth TFT, the seventh TFT and the eighth TFT are electrically connected to 0V voltage to form a low potential circuit loop.
A preferred embodiment according to the present application, the inverter includes a ninth TFT, a tenth TFT, an eleventh TFT and a twelfth TFT; wherein a gate of the ninth TFT and a gate of the twelfth TFT are electrically connected to the output terminals of the first comparator and the second comparator, a drain of the ninth TFT is electrically connected to a drain of the twelfth TFT, and is electrically connected to −10V voltage to form a low potential circuit loop; a source of the ninth TFT is electrically connected to a source of the eleventh TFT, and the source of the ninth TFT is electrically connected to a drain of the tenth TFT, a gate of the tenth TFT, a source of the tenth TFT and the source of the eleventh TFT are electrically connected to each other and 28V voltage to form a high potential circuit loop.
A preferred embodiment according to the present application, a structure and a function of the first comparator and the second comparator are identical and are used for inputting different low voltage signals of the GOA unit, if one of the output terminal of the first comparator and the second comparator outputs a high potential voltage, the inverter outputs a low potential voltage.
A preferred embodiment according to the present application, the switching TFT is N-type TFT.
A preferred embodiment according to the present application, the first TFT to the eighth TFT are N-type TFTs.
A preferred embodiment according to the present application, the eighth TFT to the twelfth TFT are N-type TFTs.
According to the above protection system of the GOA circuit, the present application further provides a liquid crystal display (LCD) panel which includes the protection system of the GOA circuit in the embodiments described above, the protection system of the GOA circuit includes the detection circuit connected to the GOA circuit, and configured to generate the driving signal in response to the low potential signal of the GOA circuit; and the switching circuit signally-connected to the initial trigger signal, the detection circuit and the GOA circuit, the switching circuit configured to transmit the initial trigger signal to the GOA circuit according to the driving signal; wherein upon the low voltage level of the low potential signal, the switching circuit is turned on to conduct the initial trigger signal to the GOA circuit; and upon the high voltage level of the low potential signal, the switching circuit is turned off so that the GOA circuit does not conduct the initial trigger signal, the GOA circuit includes a plurality of stages of GOA units, except for the last stage of the GOA units, the output scan signal of each stage of the GOA units serves as a cascade signal of the next stage of the GOA units; except for the first stage of the GOA units, the output scan signal of each stage of the GOA units and a pull-down signal of a previous stage of the GOA units of the stage of the GOA unit, the pull-down signal is used to correct a waveform of the scan signal at the previous stage of the GOA units.
A preferred embodiment according to the present application, the detection circuit includes the first comparator and the inverter; the low potential signal includes the first low potential signal; the input terminal of the first comparator is signally-connected to the first low potential signal; the output terminal of the first comparator is connected to the input terminal of the inverter; the output terminal of the inverter is connected to the control terminal of the switching circuit.
A preferred embodiment according to the present application, the low potential signal further includes a second low potential signal; the detection circuit further includes the second comparator; the input terminal of the second comparator is signally-connected to the second low potential signal; both of the output terminal of the second comparator and the output terminal of the first comparator are connected to the input terminal of the inverter.
A preferred embodiment according to the present application, the switching circuit includes a switching thin film transistor (TFT); the drain of the switching TFT is signally-connected to the initial trigger signal; the source of the switching TFT is connected to the GOA circuit; the gate of the switching TFT is signally-connected to the driving signal.
A preferred embodiment according to the present application, the first comparator includes a first TFT, a second TFT, a third TFT, a fourth TFT, arranged in a first row; a fifth TFT, a sixth TFT, a seventh TFT and an eighth TFT, arranged in a second row; wherein sources of the first TFT, the second TFT, the third TFT and the fourth TFT are electrically connected to 28V voltage to form a high potential circuit loop; drains of the fifth TFT, the sixth TFT, the seventh TFT and the eighth TFTs are electrically connected to 0V voltage to form a low potential circuit loop.
A preferred embodiment according to the present application, the inverter includes a ninth TFT, a tenth TFT, an eleventh TFT, a twelfth TFT; wherein a gate of the ninth TFT and a gate of the twelfth TFT are electrically connected to the output terminals of the first comparator and the second comparator, a drain of the ninth TFT is electrically connected to a drain of the twelfth TFT, and is electrically connected to −10V voltage to form a low potential circuit loop; a drain of the ninth TFT is electrically connected to a drain of the eleventh TFT, and a source of the ninth TFT is electrically connected to a drain of the tenth TFT, a gate of the tenth TFT, a source of the tenth TFT and a source of the eleventh TFT are electrically connected to each other and 28V voltage to form a high potential circuit loop.
A preferred embodiment according to the present application, a structure and a function of the first comparator and the second comparator are identical and are used for inputting different low voltage signals of the GOA unit, if one of the output terminal of the first comparator and the second comparator outputs a high potential voltage, the inverter outputs a low potential voltage.
A preferred embodiment according to the present application, the switching TFT is N-type TFT.
A preferred embodiment according to the present application, the first TFT to the eighth TFT are N-type TFTs.
A preferred embodiment according to the present application, the eighth TFT to the twelfth TFT are N-type TFTs.
The present application provides a protection system and a liquid crystal display panel for GOA circuit, the protection system of the GOA circuit of the present application
In order to illustrate the embodiments or the technical solutions in the prior art more clearly, the drawings used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only for some embodiments of the invention, and those skilled in the art can obtain other drawings according to the drawings without any creative work.
The following description of the various embodiments is provided with reference to the accompanying drawings. Directional terms, such as upper, lower, front, back, left, right, inner, outer, and lateral side, mentioned in the present invention are only for reference. Therefore, the directional terms are used for describing and understanding rather than limiting the present invention. In the figures, units having similar structures are used for the same reference numbers.
The present application focuses on technical problems existing in the prior art, regarding large current, abnormal operation of the whole GOA circuit, and abnormal display and LCD panel burn-out caused by a short circuit between a low potential signal VSSQ/VSSG with a high-potential signal in any one of the GOA units of multiple cascade GOA units in the GOA circuit of the LCD panel. This embodiment provides a solution to these defects.
As shown in
In this embodiment, the GOA circuit includes a plurality of stages of GOA units, except for the last stage of the GOA units, an output scan signal of each stage of the GOA units serves as a cascade signal of the next stage of the GOA units; except for the last stage of the GOA units, the output scan signal of each stage of the GOA units serves as a pull-down signal of the previous stage of the GOA units of the stage of the GOA unit, the pull-down signal is used to correct the waveform of the scan signal at the previous stage of the GOA units. For example, a first stage GOA unit 101 outputs a scan signal G001, the scan signal G001 is transmitted to a second stage GOA unit 102, and serves as a cascade signal of the second stage GOA unit 102 through a signal line 1012. The second stage GOA unit 102 outputs a scan signal G002 which serves as a pull-up signal of the first stage GOA unit 101, the pull-up signal is transmitted to the first stage GOA unit 101 through a signal line 1011. The cascade signals of other GOA units are transmitted same as described above to make the GOA circuit operate normally, and thus will not be further described.
As shown in
As shown in
The first comparator includes a first TFT 301, a second TFT 302, a third TFT 303, a fourth TFT 304, a fifth TFT 305, a sixth TFT 306, a seventh TFT 307, and an eighth TFT 308. The first TFT 301, the second TFT 302, the third TFT 303, and the fourth TFT 304 are arranged in a first row, and sources of the first TFT 301, the second TFT 302, the third TFT 303, and the fourth TFT 304 are electrically connected to a 28V voltage to form a high potential circuit loop. The fifth TFT 305, the sixth TFT 306, the seventh TFT 307, and the eighth TFT 308 are arranged in a second row, and drains of the fifth TFT 305, the sixth TFT 306, the seventh TFT 307, and the eighth TFT 308 are electrically connected to a 0V voltage to form a low potential circuit loop. In the present embodiment, the first low potential signal VSSQ is −8V, the second low potential signal VSSG is −6V. After a period of time, the second low potential signal VSSG changes from −6V to a high voltage which is between 0V and 28V, as shown in
The converter 33 includes a ninth TFT 309, a tenth TFT 3010, an eleventh TFT 3011, and a twelfth TFT 3012. The gate of the ninth TFT 309 and the gate of the twelfth TFT 3012 are electrically connected to the output terminal of the first comparator 31 and the output terminal of the second comparator 32. The drain of the ninth TFT 309 is electrically connected to the drain of the twelfth TFT 3012 and is electrically connected to −10V voltage to form the low potential circuit loop. A source of the ninth TFT 309 is electrically connected to a source of the eleventh TFT 3011, and the source of the ninth TFT 309 is electrically connected to a drain of the tenth TFT 3010, the gate of the tenth TFT 3010, the source of the tenth TFT 3010 and the source of the eleventh TFT 3011 are electrically connected to each other and 28V voltage to form the high potential circuit loop. In this embodiment, the first to the twelfth TFTs are N-type TFTs. The first low potential signal VSSQ is −8V, the second low potential signal VSSG is −6V, the converter 33 outputs 28V, and the switching circuit 10 is turned on so that the GOA circuit works normally. The first low potential signal VSSQ is −8V, when the GOA circuit experiences a short circuit, the voltage of the second low potential signal VSSG will rise above 0V, the converter 33 outputs −10V, the switching circuit 10 is turned off so that the first stage GOA unit 101 in the GOA circuit does not conduct the initial trigger signal STV, and the GOA circuit stops working, and the LCD panel is protected from burn-out, as shown in
According to above GOA circuit, the present application further provides an LCD panel which includes the GOA circuit described above.
The present application provides the protection system for the GOA circuit and the LCD panel. The protection system for the GOA circuit of the present application includes the detection circuit which is connected to the GOA circuit, and is configured to generate the driving signal in response to the low potential signal of the GOA circuit; and the switching circuit which is signally-connected to the initial trigger signal, the detection circuit and the GOA circuit, the switching circuit is configured to transmit the initial trigger signal to the GOA circuit according to the driving signal. Upon the low voltage level of the low potential signal, the switching circuit is turned on to conduct the initial trigger signal to the GOA circuit, and upon the high voltage level of the low potential signal, the switching circuit is turned off so that the GOA circuit does not conduct the initial trigger signal, and the GOA circuit stops working to protect the LCD panel from burn-out.
The above disclosures are the preferred embodiments of the present invention. However, these embodiments are not intended to limit the present invention. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims.
Number | Date | Country | Kind |
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202010257397.8 | Apr 2020 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2020/087748 | 4/29/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
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WO2021/196330 | 10/7/2021 | WO | A |
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