CN209993327U - Shutdown control circuit and display device thereof - Google Patents
Shutdown control circuit and display device thereof Download PDFInfo
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- CN209993327U CN209993327U CN201920872324.2U CN201920872324U CN209993327U CN 209993327 U CN209993327 U CN 209993327U CN 201920872324 U CN201920872324 U CN 201920872324U CN 209993327 U CN209993327 U CN 209993327U
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- 238000001514 detection method Methods 0.000 claims description 34
- 230000003247 decreasing effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000008030 elimination Effects 0.000 description 3
- 238000003379 elimination reaction Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
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- 238000000034 method Methods 0.000 description 1
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Abstract
The shutdown control circuit generates a shutdown control signal, controls the driving circuit to release residual charges in the display panel when the shutdown control signal is in an effective level state, and comprises a voltage division network for collecting power supply voltage; a comparator that compares the supply voltage with a reference voltage; and the control module is connected with the comparator and generates a shutdown control signal according to the comparison result and the state of the backlight enabling signal, and controls to light the backlight source of the display panel when the backlight enabling signal is in an effective level state. The shutdown control circuit is used for preventing the false triggering of the shutdown ghost eliminating operation caused by improper setting of the reference voltage by detecting the level state of the backlight enabling signal. The utility model discloses can effectively release the residual charge in the pixel when display device shuts down to reduced simultaneously and eliminated the influence that shutdown ghost operation led to the fact display panel display quality because of the false triggering.
Description
Technical Field
The utility model relates to a show technical field, especially relate to a shutdown control circuit and display device thereof.
Background
When the display device is turned off, residual charges usually exist on the pixel electrodes, and need to be released in time during the turn-off process, so as to avoid the shutdown ghost phenomenon.
In the prior art, when the power supply voltage is reduced to the reference voltage triggering the shutdown residual image elimination function, the shutdown residual image elimination function is started, and the thin film transistors in all the pixels are turned on to release charges in the pixel electrodes, so that the shutdown residual image phenomenon is eliminated. However, the reference voltage set in the conventional shutdown control circuit is low, which causes insufficient charge release when the display device is shutdown, and causes charge accumulation and image flicker after the display device is rapidly turned on and off for many times. When the reference voltage in the shutdown control circuit is set to be higher, the power supply voltage VIN of the display device is reduced due to the existence of high probability current in the startup state, so that the shutdown ghost eliminating operation is triggered by mistake to cause abnormal display pictures, and the user experience is reduced.
SUMMERY OF THE UTILITY MODEL
In view of the above, an object of the present invention is to provide a shutdown control circuit and a display device thereof, so as to effectively release residual charges in pixels when the display device is shutdown, and simultaneously reduce the influence of the shutdown ghost eliminating operation on the display quality of the display panel due to false triggering.
According to an aspect of the present invention, there is provided a power-off control circuit for generating a power-off control signal, the power-off control signal controlling a driving circuit to release residual charges in a display panel when in an active level state, the power-off control circuit comprising a voltage dividing network for collecting a supply voltage; a comparator that compares the supply voltage with a reference voltage; and the control module is connected with the comparator and generates a shutdown control signal according to a comparison result and the state of the backlight enabling signal, and the backlight source of the display panel is controlled to be lightened when the backlight enabling signal is in an effective level state.
Preferably, when the power supply voltage reaches a reference voltage value and the backlight enable signal is in an inactive level state, the shutdown control circuit generates the shutdown control signal.
Preferably, a first input terminal of the comparator is connected to and receives the supply voltage via the voltage dividing network, a second input terminal of the comparator is connected to and receives the reference voltage, and an output terminal of the comparator outputs the comparison result.
Preferably, the control module includes a detection unit connected to an output terminal of the comparator to receive the comparison result, and configured to detect the comparison result and a state of the backlight enable signal and output a detection result; and the selection unit outputs the shutdown control signal in a corresponding level state according to the detection result.
Preferably, the detection unit includes a first switch tube, a first path end of the first switch tube is connected to receive a positive voltage, and a control end of the first switch tube is connected to the output end of the comparator; a first path end of the second switching tube is connected with a second path end of the first switching tube, the second path end of the second switching tube is used as an output end of the detection unit to output the detection result, and a control end of the second switching tube is connected with and receives the backlight enabling signal; a first path end of the third switching tube is connected with the output end of the detection unit, a second path end of the third switching tube is grounded, and a control end of the third switching tube is connected with the output end of the comparator; and the first path end of the fourth switch tube is connected with the output end of the detection unit, the second path end of the fourth switch tube is grounded, and the control end of the fourth switch tube is connected with and receives the backlight enabling signal.
Preferably, the first switching tube and the third switching tube have different conductivity types, and the second switching tube and the fourth switching tube have different conductivity types.
Preferably, the selection unit includes: a fifth switching tube, a first path end of which is connected to and receives the positive voltage, a second path end of which is used as an output end of the selection unit to output the shutdown control signal, and a control end of which is connected to an output end of the detection unit; and the first path end of the sixth switching tube is connected with the output end of the selection unit, the second path end of the sixth switching tube is grounded, and the control end of the sixth switching tube is connected with the output end of the detection unit.
Preferably, the fifth switching tube and the sixth switching tube have different conductivity types.
Preferably, the detection circuit further comprises a fifth resistor, one end of the fifth resistor is connected to the output end of the comparator, and the other end of the fifth resistor is connected to the detection unit.
According to another aspect of the present invention, there is provided a display device, including the shutdown control circuit provided above.
The utility model provides a shutdown control circuit and display device thereof, shutdown control circuit are through the level state that detects supply voltage and enable signal in a poor light to produce the shutdown control signal that corresponds the level state, and drive gate drive circuit when shutdown control signal is in effective level state and carry out the operation of eliminating the shutdown ghost. The level state of the backlight enabling signal is detected to avoid false triggering of shutdown ghost elimination operation caused by improper setting of the reference voltage. The utility model discloses can effectively release the residual charge in the pixel when display device shuts down to reduced simultaneously and eliminated the influence that shutdown ghost operation led to the fact display panel display quality because of the false triggering.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:
fig. 1 shows a block diagram of a shutdown control circuit according to an embodiment of the present invention;
fig. 2 shows a circuit schematic of a shutdown control circuit according to an embodiment of the invention;
fig. 3 shows a timing diagram of a shutdown control circuit according to an embodiment of the present invention.
Detailed Description
Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by the same or similar reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale.
The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples.
Fig. 1 shows a block diagram of a shutdown control circuit according to an embodiment of the present invention.
The shutdown control circuit generates a shutdown control signal and outputs the shutdown control signal to the gate drive circuit by detecting the power supply condition in the display device and the working state of the display screen, wherein the shutdown control signal is used for controlling and releasing residual charges on pixel electrodes in the display panel.
As shown in fig. 1, the shutdown control circuit 100 includes a comparator U1 and a control module 120.
A first input terminal of the comparator U1 is connected to receive the collected supply voltage Vin, a second input terminal of the comparator U1 is connected to receive a reference voltage V1, and an output terminal of the comparator U1 outputs a comparison result between the supply voltage Vin and the reference voltage V1. The reference voltage V1 is set in advance, for example, empirically.
The control module 120 includes a detection unit 121 and a selection unit 122. The detection unit 121 is connected to the output terminal of the comparator U1 to receive the comparison result of the power supply voltage Vin and the reference voltage V1, and is connected to receive the backlight enable signal EN, for detecting the states of the comparison result and the backlight enable signal EN and outputting the detection result. The backlight source for lighting the display panel in the display device is controlled when the backlight enable signal is in an active level state. The selecting unit 122 is connected to the detecting unit 121 to receive the detection result and output the shutdown control signal Xon corresponding to the level state according to the detection result. When the shutdown control signal Xon is in an active level state, the driving gate driving circuit turns on all the thin film transistors in the pixel electrode of the display panel to release charges remaining in the pixel electrode during shutdown.
The shutdown control circuit 100 detects the power supply voltage Vin and the backlight enable signal EN, after the display device is shutdown, when the power supply voltage Vin is reduced to the preset reference voltage V1 and the backlight enable signal EN is in an inactive level state, the shutdown control circuit 100 generates the shutdown control signal Xon in an active level state to drive a gate driving circuit in the display device to release charges remaining in a pixel electrode, thereby avoiding a shutdown ghost phenomenon. When the power supply voltage Vin is not lowered to the reference voltage V1 and/or the backlight enable signal EN is in an inactive level state, the shutdown control circuit generates a shutdown control signal Xon in the inactive level state, and the gate driving circuit does not start the operation of eliminating shutdown ghost.
Fig. 2 shows a circuit schematic diagram of a shutdown control circuit according to an embodiment of the present invention.
As shown in fig. 2, the shutdown control circuit 100 includes a comparator U1, a voltage dividing network 111, a detection unit 121, and a selection unit 122.
The voltage dividing network 111 comprises a first resistor R1 and a second resistor R2, wherein the first resistor R1 is connected in series with the second resistor R2, the other end of the first resistor R1 is connected with and receives the supply voltage Vin, the other end of the second resistor R2 is grounded, and an intermediate node where the first resistor R1 and the second resistor R2 are connected serves as an output end of the voltage dividing network 111.
A forward input terminal of the comparator U1 is connected to the output terminal of the voltage divider network 111 via, for example, a third resistor R3 to receive the supply voltage Vin, a reverse input terminal of the comparator U1 is connected to and receives the reference voltage V1 via a fourth resistor R4, a forward power terminal of the comparator U1 is connected to and receives the first voltage V2, and a reverse power terminal of the comparator U1 is grounded. Wherein the reference voltage V1 is smaller than the first voltage V2, the reference voltage V1 may be, for example, between 1.2V and 2V.
The detecting unit 121 includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4, a first path end of the first switch tube Q1 is connected to receive a second voltage V3, the second voltage V3 is, for example, a positive voltage, and a control end of the first switch tube Q1 is connected to the output end of the comparator U1 through a fifth resistor R5. The first path end of the second switch tube Q2 is connected to the second path end of the first switch tube Q1, the second path end of the second switch tube Q2 is used as the output end of the detection unit to output the detection result, and the control end of the second switch tube Q2 is connected to and receives the backlight enable signal EN. A first path terminal of the third switching tube Q3 is connected to the output terminal of the detection unit 121, a second path terminal of the third switching tube Q3 is grounded, and a control terminal of the third switching tube Q3 is connected to the output terminal of the comparator U1 via the fifth resistor Q5. A first path end of the fourth switching tube Q4 is connected to the output end of the detection unit 121, a second path end of the fourth switching tube Q4 is grounded, and a control end of the fourth switching tube Q4 is connected to receive the backlight enable signal EN. The first switching tube Q1 and the third switching tube Q3 have different conductivity types, and the second switching tube Q2 and the fourth switching tube Q4 have different conductivity types. In this embodiment, the first switch tube Q1 and the second switch tube Q2 are P-type tubes, the third switch tube Q4 and the fourth switch tube Q4 are N-type tubes, and the backlight enable signal EN is a backlight source that is high level and effectively lights up the display panel. However, this embodiment is merely for clarity of illustration and is not intended to limit the present invention.
The selection unit 122 includes a fifth switch Q5 and a sixth switch Q6. A first path terminal of the fifth switch Q5 is connected to receive the second voltage V3, a second path terminal of the fifth switch Q5 is used as an output terminal of the selection unit 122 to output the shutdown control signal Xon, and a control terminal of the fifth switch Q5 is connected to the output terminal of the detection unit 121. The first path terminal of the sixth switch Q6 is connected to the output terminal of the selected unit 122, the second path terminal of the sixth switch Q6 is grounded, and the control terminal of the sixth switch Q6 is connected to the output terminal of the detecting unit 121. The fifth switching tube Q5 and the sixth switching tube Q6 have different conductivity types. In this embodiment, the fifth switching tube Q5 is a P-type tube, and the sixth switching tube Q6 is an N-type tube.
When the supply voltage Vin is not lowered to the reference voltage V1 and the enable signal EN is at a high level of an active state, the third switch Q3, the fourth switch Q4 and the fifth switch Q5 are turned on, and the output shutdown control signal is at a high level of an inactive state.
When the supply voltage Vin is not lowered to the reference voltage V1 and the enable signal EN is at a low level of an inactive state, the third switch Q3, the second switch Q2 and the fifth switch Q5 are turned on, and the output shutdown control signal is at a high level of an inactive state.
When the supply voltage Vin has decreased to the reference voltage V1 and the enable signal EN is at a high level of an active state, the first switch Q1, the fourth switch Q4 and the fifth switch Q5 are turned on, and the output shutdown control signal is at a high level of an inactive state.
When the power supply voltage Vin has decreased to the reference voltage V1 and the enable signal EN is at a low level in an inactive state, the first switch tube Q1, the second switch tube Q2 and the sixth switch tube Q6 are turned on, the output shutdown control signal is at a low level active state, and at this time, the gate driving circuit is driven to start the operation of eliminating shutdown ghost.
Fig. 3 shows a timing diagram of a shutdown control circuit according to an embodiment of the present invention.
As shown in fig. 3, when the display apparatus performs the shutdown operation, the power supply voltage Vin is decreased, and when the power supply voltage Vin is decreased to the reference voltage V1 and when the backlight enable signal EN is in the low-level inactive state, the shutdown control signal Xon at the low level in the active state is output. If the supply voltage Vin has decreased to the reference voltage V1, but the backlight enable signal EN is still active at a high level, the output power-off control signal Xon is still the high-level power-off control signal Xon.
The utility model also provides a display device, including the shutdown control circuit that the aforesaid provided, this shutdown control circuit output is used for starting or closes the shutdown control signal who eliminates shutdown ghost operation. The shutdown control signal acts on a gate driving circuit in the display device to release residual charges in the display panel when the display device is shut down.
In accordance with the embodiments of the present invention as set forth above, these embodiments are not exhaustive and do not limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and its various embodiments with various modifications as are suited to the particular use contemplated. The present invention is limited only by the claims and their full scope and equivalents.
Claims (10)
1. A shutdown control circuit generates a shutdown control signal, controls a driving circuit to release residual charges in a display panel when the shutdown control signal is in an effective level state, comprises a voltage division network for collecting a supply voltage, and is characterized by further comprising:
a comparator that compares the supply voltage with a reference voltage; and
and the control module is connected with the comparator and generates a shutdown control signal according to a comparison result and the state of the backlight enabling signal, and the backlight source of the display panel is controlled to be lightened when the backlight enabling signal is in an effective level state.
2. The power-off control circuit of claim 1, wherein the power-off control circuit generates the power-off control signal when the supply voltage reaches a reference voltage value and the backlight enable signal is in an inactive level state.
3. The shutdown control circuit of claim 1, wherein a first input terminal of the comparator is connected to receive the supply voltage via the voltage dividing network, a second input terminal of the comparator is connected to receive the reference voltage, and an output terminal of the comparator outputs the comparison result.
4. The shutdown control circuit of claim 3, wherein the control module comprises:
the detection unit is connected with the output end of the comparator to receive the comparison result, and is used for detecting the states of the comparison result and the backlight enabling signal and outputting a detection result; and
and the selection unit outputs the shutdown control signal in a corresponding level state according to the detection result.
5. The shutdown control circuit of claim 4, wherein the detection unit comprises:
the first pass end of the first switch tube is connected with and receives a positive voltage, and the control end of the first switch tube is connected with the output end of the comparator;
a first path end of the second switching tube is connected with a second path end of the first switching tube, the second path end of the second switching tube is used as an output end of the detection unit to output the detection result, and a control end of the second switching tube is connected with and receives the backlight enabling signal;
a first path end of the third switching tube is connected with the output end of the detection unit, a second path end of the third switching tube is grounded, and a control end of the third switching tube is connected with the output end of the comparator; and
and a first path end of the fourth switch tube is connected with the output end of the detection unit, a second path end of the fourth switch tube is grounded, and a control end of the fourth switch tube is connected with and receives the backlight enabling signal.
6. The shutdown control circuit of claim 5, wherein the first switching tube and the third switching tube are of different conductivity types, and the second switching tube and the fourth switching tube are of different conductivity types.
7. The shutdown control circuit of claim 5, wherein the selection unit comprises:
a fifth switching tube, a first path end of which is connected to and receives the positive voltage, a second path end of which is used as an output end of the selection unit to output the shutdown control signal, and a control end of which is connected to an output end of the detection unit; and
and the first path end of the sixth switching tube is connected with the output end of the selection unit, the second path end of the sixth switching tube is grounded, and the control end of the sixth switching tube is connected with the output end of the detection unit.
8. The shutdown control circuit of claim 7, wherein the fifth switching tube and the sixth switching tube are of different conductivity types.
9. The shutdown control circuit of claim 4, further comprising:
one end of the fifth resistor is connected with the output end of the comparator, and the other end of the fifth resistor is connected with the detection unit.
10. A display device comprising the power-off control circuit according to any one of claims 1 to 9.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920872324.2U CN209993327U (en) | 2019-06-11 | 2019-06-11 | Shutdown control circuit and display device thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920872324.2U CN209993327U (en) | 2019-06-11 | 2019-06-11 | Shutdown control circuit and display device thereof |
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| CN209993327U true CN209993327U (en) | 2020-01-24 |
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| CN201920872324.2U Active CN209993327U (en) | 2019-06-11 | 2019-06-11 | Shutdown control circuit and display device thereof |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112735346A (en) * | 2020-12-30 | 2021-04-30 | 昆山龙腾光电股份有限公司 | Shutdown control circuit, shutdown control method and display device |
| CN113707105A (en) * | 2021-08-18 | 2021-11-26 | Tcl华星光电技术有限公司 | Delay circuit and voltage control chip |
-
2019
- 2019-06-11 CN CN201920872324.2U patent/CN209993327U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112735346A (en) * | 2020-12-30 | 2021-04-30 | 昆山龙腾光电股份有限公司 | Shutdown control circuit, shutdown control method and display device |
| CN112735346B (en) * | 2020-12-30 | 2022-03-25 | 昆山龙腾光电股份有限公司 | Shutdown control circuit, shutdown control method and display device |
| CN113707105A (en) * | 2021-08-18 | 2021-11-26 | Tcl华星光电技术有限公司 | Delay circuit and voltage control chip |
| CN113707105B (en) * | 2021-08-18 | 2022-08-23 | Tcl华星光电技术有限公司 | Delay circuit and voltage control chip |
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