CN104537998A - Control circuit and method used for liquid crystal display device - Google Patents
Control circuit and method used for liquid crystal display device Download PDFInfo
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- CN104537998A CN104537998A CN201510004577.4A CN201510004577A CN104537998A CN 104537998 A CN104537998 A CN 104537998A CN 201510004577 A CN201510004577 A CN 201510004577A CN 104537998 A CN104537998 A CN 104537998A
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- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims abstract description 17
- 230000000630 rising effect Effects 0.000 claims description 12
- 230000007704 transition Effects 0.000 claims description 9
- 230000002159 abnormal effect Effects 0.000 abstract description 9
- 101100041125 Arabidopsis thaliana RST1 gene Proteins 0.000 description 11
- 101100443250 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) DIG1 gene Proteins 0.000 description 11
- 101100443251 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) DIG2 gene Proteins 0.000 description 10
- 101100041128 Schizosaccharomyces pombe (strain 972 / ATCC 24843) rst2 gene Proteins 0.000 description 10
- 238000010586 diagram Methods 0.000 description 6
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
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- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Liquid Crystal Display Device Control (AREA)
Abstract
The invention provides a control circuit and method used for a liquid crystal display device. The control circuit comprises a signal adapter, a time sequence controller, a panel drive module and a backlight drive module, wherein the signal adapter is used for receiving a clock signal, a first power source signal and a control signal; the time sequence controller is used for receiving the clock signal and outputting a grey-scale data signal to a liquid crystal panel; the panel drive module is used for receiving the first power source signal and outputting a backlight reset signal, a panel reset signal and a panel drive signal; the backlight drive module is used for receiving the control signal and the backlight reset signal and outputting the backlight drive signal to a backlight module. Compared with the prior art, when a power source of the panel suddenly falls down, the panel drive module firstly outputs the backlight reset signal to the backlight drive module to stop lightening an LED light strip and then outputs the panel reset signal to the liquid crystal panel to reset the liquid crystal panel, and therefore the undesirable phenomenon that an existing panel easily has an abnormal image corresponding to useless grey-scale data is solved.
Description
Technical Field
The present invention relates to a liquid crystal display device, and more particularly, to a control circuit and a control method for the liquid crystal display device.
Background
In recent years, a considerable number of electronic products are being developed to be portable, such as light weight, thin thickness, and short and small length, to meet the demands of consumer markets. One existing solution is to continuously compress the volume of the electronic components or to continuously integrate and enhance the implementation functions of the integrated chip to replace the traditional bulky electronic components or more complex IC application designs.
Taking the lcd panel of the notebook computer as an example, in order to achieve the above purpose, some new signal interfaces are often developed and introduced, and an Integrated Chip (Integrated Chip) with powerful functions is designed. However, in cooperation with the Client System, it is still necessary to define the normal power ON/OFF sequence for turning ON and OFF the liquid crystal panel normally. In addition, the control time sequence can also avoid bad pictures of the liquid crystal panel at the moment of startup and shutdown caused by some error time sequences. However, when abnormal shutdown such as battery falling occurs, the time point when the backlight module is turned off is usually later than the time point when the panel loses the capability of normally lighting the pattern, so that an abnormal picture corresponding to useless gray scale data is likely to appear on the panel.
In view of the above, a problem to be solved by those skilled in the art is how to improve the conventional on/off control timing or reconfigure the related control circuit to solve the abnormal screen of the panel when the battery falls off.
Disclosure of Invention
In view of the above-mentioned defects of the control circuit for the liquid crystal display device in the prior art when the panel is turned on or off, the present invention provides a control circuit for the liquid crystal display device and a control method thereof.
According to an aspect of the present invention, there is provided a control circuit for an lcd device, the lcd device including an lcd panel and a backlight module, the control circuit comprising:
the signal connector is used for receiving a clock signal, a first power supply signal and a control signal;
the time schedule controller is electrically coupled to the signal connector and the liquid crystal panel, receives the clock signal and outputs a gray scale data signal to the liquid crystal panel;
a panel driving module electrically coupled to the signal connector, the timing controller and the liquid crystal panel for receiving the first power signal and outputting a backlight reset signal, a panel reset signal and a panel driving signal; and
and the backlight driving module is electrically coupled to the signal connector, the panel driving module and the backlight module, and is used for receiving the control signal and the backlight reset signal and outputting a backlight driving signal to the backlight module.
In one embodiment, when the first power signal is lower than a reference voltage, the panel reset signal and the backlight reset signal both jump from a low level to a high level, and a rising edge transition time of the backlight reset signal is earlier than a rising edge transition time of the panel reset signal.
In one embodiment of the present invention, when the control circuit works normally, the first power signal is at a high level, the panel reset signal and the backlight reset signal are at a low level, and the second power signal is at a high level.
In an embodiment of the disclosure, the control signal includes a second power signal and a pulse width modulation signal, and the backlight driving module outputs the backlight driving signal according to a level state of the backlight reset signal.
In one embodiment, the backlight module includes an LED light bar, and the backlight driving signal is a dimming pulse signal for adjusting a light brightness of the LED light bar.
In one embodiment, the timing controller further receives a panel reset signal from the panel driving module, and determines whether to output the gray-scale data signal according to a level state of the panel reset signal.
In one embodiment, the panel driving module and the backlight driving module are integrated on a same digital integrated chip.
According to another aspect of the present invention, a control method for an lcd device including an lcd panel and a backlight module is provided, the control method comprising the steps of:
providing a time sequence controller for receiving a clock signal and outputting a gray scale data signal to the liquid crystal panel;
providing a panel driving module for receiving a first power signal and outputting a backlight reset signal, a panel reset signal and a panel driving signal;
providing a backlight driving module for receiving a control signal and the backlight reset signal and outputting a backlight driving signal to the backlight module; and
when the first power supply signal is lower than a reference voltage, the panel reset signal and the backlight reset signal jump from a low level to a high level, and the rising edge jump time of the backlight reset signal is earlier than that of the panel reset signal.
In one embodiment, the control method further includes the steps of: the time schedule controller receives a panel reset signal from the panel driving module and determines whether to output the gray scale data signal according to the level state of the panel reset signal.
In one embodiment, the panel driving module and the backlight driving module are integrated on a same digital integrated chip.
When the first power supply signal is lower than a reference voltage, the panel reset signal and the backlight reset signal jump from low level to high level, and the rising edge jump time of the backlight reset signal is earlier than that of the panel reset signal. Compared with the prior art, when the power supply of the panel suddenly drops, the panel driving module outputs a backlight reset signal to the backlight driving module to stop lighting the LED light bar, and then outputs a panel reset signal to the liquid crystal panel to reset the liquid crystal panel, so that the problem that the existing panel is easy to have an abnormal picture corresponding to useless gray scale data is solved.
Drawings
The various aspects of the present invention will become more apparent to the reader after reading the detailed description of the invention with reference to the attached drawings. Wherein,
fig. 1 is a schematic diagram showing a structure of a control circuit for a liquid crystal display device in the related art;
FIG. 2 illustrates timing waveforms of key signals in the control circuit of FIG. 1;
FIG. 3 is a schematic diagram of a control circuit for an LCD device according to an embodiment of the present invention;
FIG. 4 illustrates timing waveforms of key signals in the control circuit of FIG. 3; and
fig. 5 is a flowchart illustrating a control method for a liquid crystal display device according to another embodiment of the present invention.
Detailed Description
In order to make the present disclosure more complete and complete, reference is made to the accompanying drawings, in which like references indicate similar or analogous elements, and to the various embodiments of the invention described below. However, it will be understood by those of ordinary skill in the art that the examples provided below are not intended to limit the scope of the present invention. In addition, the drawings are only for illustrative purposes and are not drawn to scale.
Fig. 1 is a schematic diagram showing a structure of a control circuit for a liquid crystal display device according to the related art, and fig. 2 is a timing waveform diagram showing key signals in the control circuit of fig. 1. Referring to fig. 1 and 2, the conventional control circuit includes a signal connector 100, a timing controller 102, a panel driving module 104, and a backlight driving module 106. For example, the backlight module 106 includes an LED light bar 108, and the backlight driving signal S2 is a dimming pulse signal for adjusting the brightness of the LED light bar 108.
The signal connector 100 is used for receiving a clock signal Clk, a first power signal V1 and a control signal Ctrl. The timing controller 102 is electrically coupled to the signal connector 100 and the liquid crystal panel, and the timing controller 102 receives the clock signal Clk and outputs a gray scale data signal Vg to the liquid crystal panel.
The panel driving module 104 is electrically coupled to the signal connector 100, the timing controller 102 and the liquid crystal panel. The panel driving module 104 receives the first power signal V1 and outputs a panel reset signal RST1 and a panel driving signal S1. The panel reset signal RST1 is transmitted not only to the liquid crystal panel but also to the timing controller 102, so that the timing controller 102 can determine whether to output the gray scale data signal Vg according to the level state of the panel reset signal RST 1. In addition, the panel driving module 104 further provides a pixel voltage Vdata to the timing controller 102, and the timing controller 102 outputs the gray-scale data signal Vg according to the clock signal Clk and the pixel voltage Vdata.
The backlight driving module 106 is electrically coupled to the signal connector 100 and the LED light bar 108 in the backlight module. The backlight driving module 106 is configured to receive the control signal Ctrl and output a backlight driving signal S2 to the LED light bar 108 of the backlight module according to the control signal Ctrl. The control signal Ctrl includes a second power signal V2 and a pulse width modulation signal Vpwm, the second power signal V2 is used for providing the operating voltage of the backlight module, and the pulse width modulation signal Vpwm is used for providing the enable signal of the backlight driving module 106. When the pulse width modulation signal Vpwm is in an enable state (enable status), allowing the backlight driving module 106 to output a backlight driving signal S2; when the pulse width modulation signal Vpwm is in a disable state, the backlight driving module 106 is disabled from outputting the backlight driving signal S2.
As shown in fig. 2, in the normal lighting pattern of the liquid crystal panel, the first power signal V1 is 3.3V (e.g., high level), the second power signal V2 is 12V (e.g., high level), the operating voltage of the timing controller Tcon is 2.5V, the panel reset signal RST1 is low level, and the pulse width modulation signal Vpwm is 3.3V (e.g., high level). As described above, when an abnormal shutdown situation such as a battery drop occurs at the time t0, the voltage drops occur in the first power signal V1, the second power signal V2, the pulse width modulation signal Vpwm, and the operating voltage of the timing controller, and the panel loses the capability of the normal lighting pattern at the time t1 in consideration of the signal delay, at which the panel reset signal RST1 jumps from the low level to the high level. However, since the time t2 when the backlight module is turned off is later than the time t1 when the panel loses the capability of normally lighting the pattern, an abnormal picture corresponding to useless gray-scale data is likely to appear on the panel, which affects the yield and quality of the product.
Fig. 3 is a schematic diagram illustrating a control circuit for an lcd device according to an embodiment of the present invention, and fig. 4 is a timing waveform diagram illustrating key signals in the control circuit of fig. 3. As shown in fig. 3, the control circuit of the present invention also includes a signal connector 100, a timing controller 102, a panel driving module 104 and a backlight driving module 106. Comparing fig. 3 with fig. 1, the signal transmission process between the panel driving module 104 and the backlight driving module 106 of the control circuit of the present invention is added.
Similarly, the signal connector 100 receives a clock signal Clk, a first power signal V1 and a control signal Ctrl. The timing controller 102 is electrically coupled to the signal connector 100 and the liquid crystal panel, and the timing controller 102 receives the clock signal Clk and outputs a gray scale data signal Vg to the liquid crystal panel. The panel driving module 104 is electrically coupled to the signal connector 100, the timing controller 102 and the liquid crystal panel.
It should be noted that the panel driving module 104 receives the first power signal V1 and outputs a backlight reset signal RST2, a panel reset signal RST1 and a panel driving signal S1. The backlight driving module 106 is electrically coupled to the signal connector 100, the panel driving module 104 and the backlight module, and the backlight driving module 106 receives the control signal Ctrl and the backlight reset signal RST2 and outputs a backlight driving signal S2 to the LED light bar 108 of the backlight module.
Referring to fig. 4, when the control circuit normally operates, the first power signal V1 is 3.3V (high level), the panel reset signal RST1 and the backlight reset signal RST2 are low level, and the second power signal V2 is 12V (high level). When an abnormal shutdown situation such as battery disconnection occurs at time t0, voltage drops occur in the first power signal V1, the second power signal V2, the pulse width modulation signal Vpwm, and the operating voltage of the timing controller. When the first power signal V1 is lower than a reference voltage Vref (e.g., time t3 in fig. 4), the pwm signal Vpwm changes from high to low, the backlight reset signal RST2 changes from low to high, and the backlight module is turned off and the LED light bar 108 is turned off. When the panel loses the capability of the normal lighting pattern at time t1, the panel reset signal RST1 also jumps from the low level to the high level at this time.
As can be seen from the above description, the rising edge transition time (time t3) of the backlight reset signal RST2 is earlier than the rising edge transition time (time t1) of the panel reset signal RST1, so that when the power supply of the panel suddenly drops, the panel driving module 104 first outputs a backlight reset signal RST2 to stop lighting the LED light bars 108, and then outputs a panel reset signal RST1 to reset the liquid crystal panel, thereby solving the problem that the conventional panel is prone to having invalid pictures when the panel is not normally turned off.
In one embodiment, the panel driving module 104 and the backlight driving module 106 may be integrated on the same digital integrated chip.
Fig. 5 is a flowchart illustrating a control method for a liquid crystal display device according to another embodiment of the present invention.
Referring to fig. 5 in combination with fig. 3 and 4, in the control method of the present invention, step S101 is first executed to provide a timing controller 102 for receiving a clock signal Clk and outputting a gray-scale data signal Vg to the liquid crystal panel. Then, step S103 is executed to provide a panel driving module 104 for receiving a first power signal V1 and outputting a backlight reset signal RST2, a panel reset signal RST1 and a panel driving signal S1. Next, step S105 is executed to provide a backlight driving module 106 for receiving a control signal Ctrl and a backlight reset signal RST2 and outputting a backlight driving signal S2 to the backlight module. In step S108, when the first power signal V1 is lower than a reference voltage Vref, the panel reset signal RST1 and the backlight reset signal RST2 both jump from low level to high level, and the rising edge transition time of the backlight reset signal RST2 is earlier than the rising edge transition time of the panel reset signal RST 1.
When the first power supply signal is lower than a reference voltage, the panel reset signal and the backlight reset signal jump from low level to high level, and the rising edge jump time of the backlight reset signal is earlier than that of the panel reset signal. Compared with the prior art, when the power supply of the panel suddenly drops, the panel driving module outputs a backlight reset signal to the backlight driving module to stop lighting the LED light bar, and then outputs a panel reset signal to the liquid crystal panel to reset the liquid crystal panel, so that the problem that the existing panel is easy to have an abnormal picture corresponding to useless gray scale data is solved.
Hereinbefore, specific embodiments of the present invention are described with reference to the drawings. However, those skilled in the art will appreciate that various modifications and substitutions can be made to the specific embodiments of the present invention without departing from the spirit and scope of the invention. Such modifications and substitutions are intended to be included within the scope of the present invention as defined by the appended claims.
Claims (10)
1. A control circuit for a liquid crystal display device, the liquid crystal display device including a liquid crystal panel and a backlight module, the control circuit comprising:
the signal connector is used for receiving a clock signal, a first power supply signal and a control signal;
the time schedule controller is electrically coupled to the signal connector and the liquid crystal panel, receives the clock signal and outputs a gray scale data signal to the liquid crystal panel;
a panel driving module electrically coupled to the signal connector, the timing controller and the liquid crystal panel for receiving the first power signal and outputting a backlight reset signal, a panel reset signal and a panel driving signal; and
and the backlight driving module is electrically coupled to the signal connector, the panel driving module and the backlight module, and is used for receiving the control signal and the backlight reset signal and outputting a backlight driving signal to the backlight module.
2. The control circuit of claim 1, wherein the panel reset signal and the backlight reset signal both transition from a low level to a high level when the first power signal is lower than a reference voltage, and wherein a rising edge transition time of the backlight reset signal is earlier than a rising edge transition time of the panel reset signal.
3. The control circuit according to claim 1, wherein when the control circuit operates normally, the first power supply signal is at a high level, the panel reset signal and the backlight reset signal are at a low level, and the second power supply signal is at a high level.
4. The control circuit of claim 1, wherein the control signal comprises a second power signal and a pulse width modulation signal, and the backlight driving module outputs the backlight driving signal according to a level state of the backlight reset signal.
5. The control circuit of claim 4, wherein the backlight module comprises an LED light bar, and the backlight driving signal is a dimming pulse signal for adjusting the brightness of the LED light bar.
6. The control circuit of claim 1, wherein the timing controller further receives a panel reset signal from the panel driving module, and determines whether to output the gray-scale data signal according to a level state of the panel reset signal.
7. The control circuit of claim 1, wherein the panel driving module and the backlight driving module are integrated on a same digital integrated chip.
8. A control method for a liquid crystal display device, the liquid crystal display device includes a liquid crystal panel and a backlight module, characterized in that, the control method includes the following steps:
providing a time sequence controller for receiving a clock signal and outputting a gray scale data signal to the liquid crystal panel;
providing a panel driving module for receiving a first power signal and outputting a backlight reset signal, a panel reset signal and a panel driving signal;
providing a backlight driving module for receiving a control signal and the backlight reset signal and outputting a backlight driving signal to the backlight module; and
when the first power supply signal is lower than a reference voltage, the panel reset signal and the backlight reset signal jump from a low level to a high level, and the rising edge jump time of the backlight reset signal is earlier than that of the panel reset signal.
9. The control method for a liquid crystal display device according to claim 8, characterized in that the control method further comprises the steps of:
the time schedule controller receives a panel reset signal from the panel driving module and determines whether to output the gray scale data signal according to the level state of the panel reset signal.
10. The method as claimed in claim 8, wherein the panel driving module and the backlight driving module are integrated on a same digital integrated chip.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510004577.4A CN104537998A (en) | 2015-01-06 | 2015-01-06 | Control circuit and method used for liquid crystal display device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201510004577.4A CN104537998A (en) | 2015-01-06 | 2015-01-06 | Control circuit and method used for liquid crystal display device |
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| CN104537998A true CN104537998A (en) | 2015-04-22 |
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| CN201510004577.4A Pending CN104537998A (en) | 2015-01-06 | 2015-01-06 | Control circuit and method used for liquid crystal display device |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106504691A (en) * | 2016-12-28 | 2017-03-15 | 合肥惠科金扬科技有限公司 | Panel display apparatus and its display control circuit |
| CN107144989A (en) * | 2017-06-06 | 2017-09-08 | 昆山龙腾光电有限公司 | A kind of width view angle switch module and liquid crystal display device |
| CN108172179A (en) * | 2017-12-14 | 2018-06-15 | 昆山龙腾光电有限公司 | Electric power management circuit |
| CN111429852A (en) * | 2020-04-20 | 2020-07-17 | 昆山龙腾光电股份有限公司 | Control circuit and control method of liquid crystal display and display device |
-
2015
- 2015-01-06 CN CN201510004577.4A patent/CN104537998A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106504691A (en) * | 2016-12-28 | 2017-03-15 | 合肥惠科金扬科技有限公司 | Panel display apparatus and its display control circuit |
| CN106504691B (en) * | 2016-12-28 | 2023-05-16 | 合肥惠科金扬科技有限公司 | Flat panel display device and display control circuit thereof |
| CN107144989A (en) * | 2017-06-06 | 2017-09-08 | 昆山龙腾光电有限公司 | A kind of width view angle switch module and liquid crystal display device |
| CN108172179A (en) * | 2017-12-14 | 2018-06-15 | 昆山龙腾光电有限公司 | Electric power management circuit |
| CN108172179B (en) * | 2017-12-14 | 2020-08-11 | 昆山龙腾光电股份有限公司 | Power management circuit |
| CN111429852A (en) * | 2020-04-20 | 2020-07-17 | 昆山龙腾光电股份有限公司 | Control circuit and control method of liquid crystal display and display device |
| CN111429852B (en) * | 2020-04-20 | 2022-04-26 | 昆山龙腾光电股份有限公司 | Control circuit and control method of liquid crystal display and display device |
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Application publication date: 20150422 |