Patent Application
20210005150
This application claims the priority of Chinese Patent Application 201910598164.1 filed on Jul. 4, 2019, the content of which is incorporated herein by reference.
The present disclosure relates to the field of display technology, and in particular, to a device and a method for controlling backlight, and a display device.
Display screens, especially liquid crystal display (LCD) screens may flicker when being turned on and off. There are many reasons for screen flickers. For example, the timing for respective signals is in chaos when turning on and off the device, especially when turning on and off the device quickly. This may cause the screen to emit light at a time that the screen is not expected to do so, thereby causing a screen flicker phenomenon.
Embodiments of the present disclosure provide a device and a method for controlling backlight, and a display device.
According to an aspect of the embodiments of the present disclosure, there is provided a device for controlling backlight, comprising: a first controlling circuit configured to receive a first power supply signal for controlling a display device to be turned on or off, and generate an output signal for causing a backlight module of the display device to be turned off, in response to the first power supply signal being in a first status for controlling the display device to be turned off; and a second controlling circuit configured to receive the first power supply signal, and generate an output signal for causing the backlight module to be turned on again after being kept in a turned off state for a predetermined time period, in response to the first power supply signal being in a second status for controlling the display device to be turned on.
For example, the first controlling circuit includes a first transistor, a second transistor, a first diode, a first capacitor, a first resistor, and a second resistor. A first electrode of the first diode is electrically coupled to a first power supply signal terminal for providing the first power supply signal, and a second electrode of the first diode is electrically coupled to a first node. A first electrode of the first capacitor is electrically coupled to the first node, and a second electrode of the first capacitor is grounded. A controlling electrode of the first transistor is electrically coupled to a second node, a first electrode of the first transistor is electrically coupled to the first node, and a second electrode of the first transistor is electrically coupled to a third node. A first terminal of the first resistor is electrically coupled to the first power supply signal terminal, and a second terminal of the first resistor is electrically coupled to the second node. A first terminal of the second resistor is electrically coupled to the third node, and a second terminal of the second resistor is grounded. In addition, a controlling electrode of the second transistor is electrically coupled to the third node, a first electrode of the second transistor is grounded, and a second electrode of the second transistor is electrically coupled to a first outputting terminal for outputting the output signal from the first controlling circuit and the second controlling circuit.
For example, the first controlling circuit further includes a second capacitor and a third resistor. A first electrode of the second capacitor is electrically coupled to the third node, and a second electrode of the second capacitor is grounded. A first terminal of the third resistor is electrically coupled to the third node, and a second terminal of the third resistor is electrically coupled to the controlling electrode of the second transistor, so as to connect the controlling electrode of the second transistor to the second electrode of the first transistor via the third resistor.
For example, the first transistor is a P-type transistor and the second transistor is an N-type transistor.
For example, the second controlling circuit includes a third transistor, a third capacitor, and a fourth resistor. A first electrode of the third capacitor is electrically coupled to a first power supply signal terminal for providing the first power supply signal, and a second electrode of the third capacitor is electrically coupled to a fourth node. A first terminal of the fourth resistor is electrically coupled to the fourth node, and a second terminal of the fourth resistor is grounded. A controlling electrode of the third transistor is electrically coupled to the fourth node, a first electrode of the third transistor is grounded, and a second electrode of the third transistor is electrically coupled to a first outputting terminal for outputting the output signal from the first controlling circuit and the second controlling circuit.
For example, the second controlling circuit comprises a fourth transistor, a fifth transistor, a fourth capacitor, a fifth resistor, a sixth resistor, a seventh resistor, and a second diode. A controlling electrode of the fourth transistor is electrically coupled to a fifth node, a first electrode of the fourth transistor is grounded, and a second electrode of the fourth transistor is electrically coupled to a sixth node. A first electrode of the second diode is electrically coupled to the fifth node, and a second electrode of the second diode is electrically coupled to a first power supply signal terminal. A first electrode of the fourth capacitor is electrically coupled to the fifth node, and a second electrode of the fourth capacitor is grounded. A controlling electrode of the fifth transistor is electrically coupled to the sixth node via a seventh resistor, a first electrode of the fifth transistor is grounded, and a second electrode of the fifth transistor is electrically coupled to a first outputting terminal for outputting the output signal from the first controlling circuit and the second controlling circuit. A first terminal of the fifth resistor is electrically coupled to the first power supply signal terminal, and a second terminal of the fifth resistor is electrically coupled to the fifth node. A first terminal of the sixth resistor is electrically coupled to the first power supply signal terminal, and a second terminal of the sixth resistor is electrically coupled to the sixth node. A first terminal of the seventh resistor is electrically coupled to the sixth node, and a second terminal of the seventh resistor is electrically coupled to the controlling electrode of the fifth transistor.
For example, the device further comprises a third controlling circuit configured to invert the output signal generated by the first controlling circuit and the second controlling circuit, and output an inverted output signal via a second outputting terminal of the device for controlling backlight.
For example, the third controlling circuit includes a sixth transistor, an eighth resistor, and a ninth resistor. A first terminal of the eighth resistor is electrically coupled to a second power supply signal terminal for providing a second power supply signal, and a second terminal of the eighth resistor is electrically coupled to a first outputting terminal for outputting the output signal from the first controlling circuit and the secondo controlling circuit. A first terminal of the ninth resistor is electrically coupled to the second power supply signal terminal, and a second terminal of the ninth resistor is electrically coupled to the second outputting terminal. A controlling electrode of the sixth transistor is electrically coupled to the first outputting terminal, a first electrode of the sixth transistor is grounded, and a second electrode of the sixth transistor is electrically coupled to the second outputting terminal.
For example, the third controlling circuit further includes a third diode, a fifth capacitor, a tenth resistor, an eleventh resistor, and a voltage stabilizing diode. A first electrode of the third diode is electrically coupled to the second power supply signal terminal, and a second electrode of the third diode is electrically coupled to the first terminal of the eighth resistor and the first terminal of the ninth resistor. A first electrode of the fifth capacitor is coupled to the second electrode of the third diode, and a second electrode of the fifth capacitor is grounded. A first terminal of the tenth resistor is electrically coupled to the first outputting terminal, and a second terminal of the tenth resistor is electrically coupled to the controlling electrode of the sixth transistor, so as to connect the controlling electrode of the sixth transistor to the first outputting terminal via the tenth resistor. A first terminal of the eleventh resistor is electrically coupled to the controlling electrode of the sixth transistor, and a second terminal of the eleventh resistor is grounded. A first electrode of the voltage stabilizing diode is grounded, and a second electrode of the voltage stabilizing diode is electrically coupled to the second outputting terminal.
For example, the third controlling circuit includes a fourth diode, a seventh transistor, a sixth capacitor, a twelfth resistor, a thirteenth resistor, and a fourteenth resistor. A first electrode of the fourth diode is electrically coupled to a second power supply signal terminal for providing a second power supply signal, and a second electrode of the fourth diode is electrically coupled to a seventh node. A first terminal of the twelfth resistor is electrically coupled to the seventh node, and a second terminal of the twelfth resistor is electrically coupled to a first outputting terminal for outputting the output signal from the first controlling circuit and the second controlling circuit. A first electrode of the sixth capacitor is electrically coupled to the seventh node, and a second electrode of the sixth capacitor is grounded. A controlling electrode of the seventh transistor is electrically coupled to the eighth node, a first electrode of the seventh transistor is grounded, and a second electrode of the seventh transistor is coupled to the second outputting terminal. A first terminal of the thirteenth resistor is electrically coupled to the first outputting terminal, and a second terminal of the thirteenth resistor is electrically coupled to the eighth node. Further, a first terminal of the fourteenth resistor is electrically coupled to the eighth node, and a second terminal of the fourteenth resistor is grounded.
For another example, the device further comprises: a fourth controlling circuit, configured to provide a third power supply signal for powering the backlight module to a third outputting terminal of the device, based on the output signal generated by the first controlling circuit or the second controlling circuit.
For example, the fourth controlling circuit includes a fifteenth resistor and a switching transistor. A first terminal of the fifteenth resistor is electrically coupled to a third power supply signal terminal for providing the third power supply signal, and a second terminal of the fifteenth resistor is electrically coupled to a first outputting terminal for outputting the output signal from the first controlling circuit and the second controlling circuit. Further, a controlling electrode of the switching transistor is electrically coupled to the first outputting terminal, a first electrode of the switching transistor is electrically coupled to the third power supply signal terminal, and a second electrode of the switching transistor is electrically coupled to the third outputting terminal.
For example, the switching transistor is a MOSFET transistor.
For another example, the first power supply signal is a voltage signal for powering a display driving circuit in the display device.
For example, the predetermined time period is longer than the time required for the display driving circuit in the display device to be powered on.
For another example, the second power supply signal is the same as the first power supply signal, or a discharging duration required for the second power supply signal to change from a first level to a second level is longer than the discharging duration required for the first power supply signal to change from the first level to the second level.
According to another aspect of the embodiments of the present disclosure, there is provided a display device, comprising: the device for controlling backlight discussed above, and the backlight module, electrically coupled to the device for controlling backlight, and configured to be turned on or off under a control of the output signal provided by the device for controlling backlight.
According to another aspect of the embodiments of the present disclosure, there is provided a method for controlling backlight, executed by the above-mentioned device. The method comprises: receiving the first power supply signal for controlling the turning on or off of the display device; generating, by the first controlling circuit, an output signal for causing the backlight module of the display device to be turned off, in response to the first power supply signal being in the first status for controlling the display device to be turned off; and generating, by the second controlling circuit, an output signal for causing the backlight module to be turned on again after being kept in the turned off state for the predetermined time period, in response to the first power supply signal being in the second status for controlling the display device to be turned on.
In order to make the objectives, 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 described clearly and completely in combination with the drawings in the embodiments of the present disclosure. Obviously, described embodiments are part of the disclosure, but not all. Based on the described embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative effort will belong to the scope defined by the embodiments of the present disclosure. It should be noted that throughout the drawings, the same elements are represented by the same or similar reference numerals. In the following description, some specific embodiments are used for description purposes only, and should not be construed as any limitation to the embodiments of the present disclosure, but merely as examples of the embodiments of the present disclosure. When it may cause confusion in the understanding of the embodiments of the present disclosure, a conventional structure or configuration will be omitted. It should be noted that the shapes and sizes of the components in the drawings do not reflect a true size and proportion, but merely illustrate the content of the embodiments of the present disclosure.
Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure shall have ordinary meanings as understood by those skilled in the art. Terms such as “first”, “second” and similar words used in the embodiments of the present disclosure do not indicate any order, quantity, or importance, but are only used to distinguish different components.
In addition, in the description of the embodiments of the present disclosure, the terms such as “connected to” or “coupled to” indicates that two components are directly connected, or that two components are connected via one or more other components. In addition, these two components can be connected or coupled by wired or wirelessly.
In addition, in the description of the embodiment of the present disclosure, the terms of “first level” and “second level” are only used to distinguish the amplitudes of the two levels. For example, the description is made by taking “the first level” being a high level and “the second level” being a low level as an example. Those skilled in the art can understand that the embodiments of the present disclosure are not limited thereto.
In the display device, such as an LCD display module or an LCD display, the problem of screen flicker may be perceived. One of the reasons for the screen flicker is that the timing for powering on has been confused when the device is quickly turned on and off. Generally, it is expected that the backlight module could be turned on after the display driving circuit of the display device is powered on, such as, after various power supply voltages Vcore in a timing controller (T-Con) and voltages Vio at general purpose input/output (GPIO) terminals are stabilized. In the case of DC turning on and off, the display driving circuit is provided with a reset delay mechanism, which can prevent the screen flicker accompanied with the turning on and off of the display device, by accurately setting the timing of each signal. However, in the case of a fast turning on and off (such as an AC turning on and off), due to the difference of the load current and the load capacitance among power supply voltages in respective channels, and the randomness of the turning on and off, it may cause the signal timing to be chaotic. For example, when the power is turned on and off frequently, the backlight module may be turned on at an unexpected time because the voltage Vcore and the voltage Vio are not discharged to the minimum operating voltage or the reset circuit is not fully discharged, thereby causing the screen flicker accompanied with the turning on and off of the display device.
The screen flicker problem can be alleviated by setting appropriate capacitor parameters which may be obtained via repeated tests. However, the repeated tests cannot completely cover different switching frequency, and even for some complicated timing confusion, it is impossible to find a suitable capacitor parameter configuration, so the above-mentioned screen flicker problem cannot be actually solved.
The embodiments of the present disclosure provide a device and a method for controlling backlight, and a display device. By monitoring the power supply signal that controls the display device to be turned on or off, such as the first power supply signal for powering the T-CON, and controlling the backlight module to be turned on or off according to the power supply signal, it can alleviate the resulting screen flicker due to the signal timing confusion during powering-on.
As shown in
The first power supply signal terminal VCC1 may be a power supply signal terminal for powering the display driving circuit (such as a timing controller T-CON) in the display device. The first power supply signal at the first power supply signal terminal VCC1 may generally have a voltage of 5V or 12V. When the first power supply signal terminal VCC1 is at the first level (for example, a high level), the first power supply signal terminal VCC1 may provide the first power supply signal being in a second status for controlling the display device (for example, the timing controller T-CON of the display device) to be turned on, and when the first power supply signal terminal VCC1 is at the second level (for example, a low level), the first power supply signal terminal VCC1 may provide the first power supply signal being in a first status for controlling the display device (for example, the timing controller T-CON of the display device) to be turned off. The predetermined time period may be longer than the time required for the display driving circuit in the display device to be powered on, for example, longer than the time required for the power supply voltage Vcore in the timing controller T-CON, voltage Vio at GPIO terminals, other logic voltages and the like being stabilized.
Each of power supply voltage Vcore in the timing controller T-CON, voltage Vio at the GPIO terminal, other logic voltages and the like are all generated based on the voltage of the first power supply signal. Examples of the voltage Vcore may include, but are not limited to, 1.5V, 1.8V, and the like. When turning on/off the device, the voltage at the first power supply signal terminal VCC1 changes before other voltages. By monitoring the voltage at the first power supply signal terminal VCC1 and controlling the turning on or off of the backlight module accordingly, it is possible to avoid the screen flicker due to the chaotic internal signal timing when the display device is turned on and off.
An example circuit structure of a backlight control device according to an embodiment of the present disclosure will be described below with reference to
As shown in
For example, the first controlling circuit 210 may include a first transistor T1, a second transistor T2, a first diode D1, a first capacitor C1, a first resistor R1, and a second resistor R2. A first electrode of the first diode D1 is electrically coupled to a first power supply signal terminal VCC1 for providing the first power supply signal, and a second electrode of the first diode D1 is electrically coupled to a first node N1. A first electrode of the first capacitor C1 is electrically coupled to the first node N1, and a second electrode of the first capacitor C1 is grounded. A controlling electrode of the first transistor T1 is electrically coupled to a second node N2, a first electrode of the first transistor T1 is electrically coupled to the first node N1, and a second electrode of the first transistor T1 is electrically coupled to a third node N3. A controlling electrode of the second transistor T2 is electrically coupled to the third node N3, a first electrode of the second transistor T2 is grounded, and a second electrode of the second transistor T2 is electrically coupled to a first outputting terminal OUT1 for outputting the output signal. A first terminal of the first resistor R1 is electrically coupled to the first power supply signal terminal VCC1, and a second terminal of the first resistor R1 is electrically coupled to the second node N2. A first terminal of the second resistor R2 is electrically coupled to the third node N3, and a second terminal of the second resistor R2 is grounded.
In some embodiments, as shown in
For example, the second controlling circuit 220 may include a third transistor T3, a third capacitor C3, and a fourth resistor R4. A first electrode of the third capacitor C3 is electrically coupled to a first power supply signal terminal VCC1 for providing the first power supply signal, and a second electrode of the third capacitor C3 is electrically coupled to a fourth node N4. A controlling electrode of the third transistor T3 is electrically coupled to the fourth node N4, a first electrode of the third transistor T3 is grounded, and a second electrode of the third transistor T3 is electrically coupled to a first outputting terminal OUT1 for outputting the output signal. A first terminal of the fourth resistor R4 is electrically coupled to the fourth node N4, and a second terminal of the fourth resistor R4 is grounded.
In
When turning on the device, the first power supply signal terminal VCC1 is at a high level, the first transistor T1 is turned off, the first controlling circuit 210 does not operate, and the third capacitor C3 in the second controlling circuit 220 starts to charge. During the charging of the third capacitor C3, the third transistor T3 is turned on, thereby pulling down the output signal of the first outputting terminal OUT1 to a low level, so that the enabling signal terminal of the backlight module is at a low level, and the backlight module does not emit light (that is, it is turned off). After a period of time, the charging of the third capacitor C3 is completed, the third transistor T3 is turned off, and the level at the first outputting terminal OUT1 is no longer pulled down, so that the enabling signal terminal of the backlight module returns to a high level, causing the backlight module to be turned on. For example, the third capacitor C3 and the fourth resistor R4 are set such that the charging time for the third capacitor C3 under the voltage of the first power supply signal terminal VCC1 equals to the above-mentioned predetermined time period, which may be longer than the timed required for respective power supply voltage Vcore in the timing controller T-CON, the voltage at the GPIO terminal, other logic voltages and the like being stabilized after being powered. Therefore, the second controlling circuit 220 can ensure that the enabling signal terminal of the backlight module is kept at a low level before the powering on of the timing controller T-CON is completed, and the level at the enabling signal terminal of the backlight module is stopped to be pulled down after the powering on of the timing controller T-CON is completed, thereby enabling the backlight module to be turned on normally.
When turning off the device, the first power supply signal terminal VCC1 is at a low level, the third transistor T3 is turned off, the second controlling circuit 220 does not operate. The first transistor T1 in the first controlling circuit 210 is turned on, so that the controlling electrode of the second transistor T2 is at a high level, turning on the second transistor T2. The turning on of the second transistor T2 cause the output signal of the first outputting terminal OUT1 to be pulled down to a low level, so that the enabling signal terminal of the backlight module is at a low level, and the backlight module is turned off.
As shown in
When turning on the device, the first power supply signal terminal VCC1 is at a high level, the first transistor T1 is turned off, the first controlling circuit 210′ does not operate, and the fourth capacitor C4 in the second controlling circuit 220′ starts to charge. During the charging of the fourth capacitor C4, the fourth transistor T4 is turned off and the fifth transistor T5 is turned on, thereby pulling down the output signal from the first outputting terminal OUT1 to a low level. After a period of time, the charging of the fourth capacitor C4 is completed, the fourth transistor T4 is turned on, causing the fifth transistor T5 to be turned off. Thus, the level at the first outputting terminal OUT1 is stopped to be pulled down, so that the enabling signal terminal of the backlight module may return to a high level, causing the backlight module to be turned on after being kept in a turned off state for a predetermined time period. The fourth transistor T4, the second diode D2, the sixth resistor R6, and the seventh resistor R7 functions to prevent interference, so that the voltage at the controlling electrode of the fifth transistor T5 is more stable.
When turning off the device, the first power supply signal terminal VCC1 is at a low level, the fifth transistor T5 is turned off, the second controlling circuit 220′ does not operate. The first controlling circuit 210′ may operate in a similar way as described above, to pull down the output signal of the first outputting terminal OUT1 to a low level, so that the enabling signal terminal of the backlight module is at a low level, and the backlight module is turned off.
An example circuit structure of a backlight control device according to another embodiment of the present disclosure will be described below with reference to
As shown in
As shown in
The second power supply signal terminal may be the same signal terminal as the first power supply signal terminal VCC1, so that the second power supply signal from the second power supply signal terminal is the same as the first power supply signal from the first power supply signal terminal VCC1. The second power supply signal terminal may be different from the first power supply signal terminal VCC1. For example, a power supply signal terminal that discharges more slowly than the first power supply signal terminal VCC1 may be selected as the second power supply signal terminal, that is, the discharging of the second power supply signal is completed after the discharging of the first power supply signal. For example, the first power supply signal and the second power supply signal may be set so that the second power supply signal is still at a high level within a period of time after the first power supply signal changes from a high level to a low level and becomes stable, when the power is turned off. In
In some embodiments, the third controlling circuit 330 may further include a third diode (such as one of the diodes D3 and D4 in
The device for controlling backlight 300 of
When turning on the device, the first power supply signal terminal VCC1 is at a high level, the first transistor T1 is turned off, the first controlling circuit 310 does not operate, and the third capacitor C3 in the second controlling circuit 320 starts to charge. During the charging of the third capacitor C3, the third transistor T3 is turned on, thereby pulling down the node P to a low level. The low level at the node P causes the sixth transistor T6 to be turned off, and the second outputting terminal OUT2 is at a high level under the bias voltage from the second power supply signal terminal (such as VCC2 or VCC3), so that the enabling signal terminal of the backlight module is also at a high level, and the backlight module does not emit light (that is, it is turned off). After a period of time, the third capacitor C3 is fully charged, the third transistor T3 is turned off, and the node P is at a high level under the bias voltage of the second power supply signal terminal (such as VCC2 or VCC3). The high level at the node P cause the sixth transistor T6 to be turned on, thereby pulling down the output signal from the second outputting terminal OUT2 to a low level. The low level at the second outputting terminal OUT2 enables the enabling signal terminal of the backlight module to be at a low level, and then the backlight module is turned on.
When turning off the device, the first power supply signal terminal VCC1 is at a low level, the third transistor T3 is turned off, the second controlling circuit 320 does not operate. The first transistor T1 in the first controlling circuit 310 is turned on, so that the controlling electrode of the second transistor T2 is at a high level, turning on the second transistor T2. The turning on of the second transistor T2 pulls the node P to a low level. The low level at the node P causes the sixth transistor T6 to be turned off, and the second outputting terminal OUT2 is at a high level under the bias voltage from the second power supply signal terminal (such as VCC2 or VCC3), so that the enabling signal terminal of the backlight module is also at a high level, and the backlight module does not emit light.
As shown in
The device for controlling backlight 300′ of
An example circuit structure of a device for controlling backlight according to another embodiment of the present disclosure will be described below with reference to
As shown in
The third controlling circuit 430 may be configured to invert the output signal generated by the first controlling circuit 410 or the second controlling circuit 420, and output an inverted output signal via a second outputting terminal OUT2 of the device for controlling backlight 400. As shown in
As shown in
An example circuit structure of a device for controlling backlight according to the embodiment of the present disclosure will be described below with reference to
As shown in
The fourth controlling circuit 540 may be configured to provide, a third power supply signal for powering the backlight module at the third power supply signal terminal VLED, to a third outputting terminal OUT3 of the device 500, based on the output signal generated by the first controlling circuit 510 or the second controlling circuit 520. As shown in
When turning on the device, the first power supply signal terminal VCC1 is at a high level, the first controlling circuit 510 does not operate, and the second controlling circuit 520 enables the node P to change into a high level after being kept in a low level for a predetermined time period. The level at the node P causes the switching transistor Q1 to be turned on after being in a turned off state for a predetermined time period, so that the power supply terminal of the backlight module is electrically connected to the third power supply signal terminal VLED after the predetermined time period is elapsed, thereby enabling the backlight module to wait for lighting until the powering on of the timing controller T-CON is completed.
When turning off the device, the first power supply signal terminal VCC1 is at a low level, the second controlling circuit 520 does not operate, and the first controlling circuit 510 pulls the node P down to a low level. The low level at the node P turns off the switching transistor Q1, so that the power supply terminal of the backlight module is disconnected from the third power supply signal terminal VLED, and thus the backlight module is turned off.
In some embodiments, the switching transistor Q1 may be a metal-oxide-semiconductor field-effect transistor (MOSFET), which may have better switching performance. Exemplarily, a controlling electrode of the MOSFET may be the gate, and a first electrode and a second electrode of the MOSFET may be the source and the drain, respectively, wherein the first electrode and the second electrode may be interchangeable. The first transistor T1, the second transistor T2, the third transistor T3, the fourth transistor T4, the fifth transistor T5, the sixth transistor T6, and the seventh transistor T7 may be bipolar junction transistors (BJT). Exemplarily, the controlling electrode of the BJT may be the base, the first electrode of the BJT may be the emitter, and the second electrode of the BJT may be the collector. However, the embodiments of the present disclosure are not limited thereto, and the types of the above-mentioned transistors may be selected as needed. In
As shown in
Although in the above embodiments, the transistors T1, T2, T3, T4, T5, T6 and T7 are all triodes, wherein the transistor T1 may be a P-type transistor, and the transistors T2, T3, T4, T5, T6 and T7 may be N-type transistors, and the switching transistor Q1 may be an N-channel enhancement mode MOSFET transistor. However, the embodiments of the present disclosure are not limited thereto, and the types of the transistors may be selected as needed. In addition, in the above embodiments, the first capacitor C1, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, and the sixth capacitor C6 may be polar capacitors, and the second capacitor C2 may be a non-polar capacitor. However, the embodiments of the present disclosure are not limited thereto, and the types of the capacitors may be selected as needed.
In step S110, the first power supply signal for controlling the turning on or off of the display device is received. The first power supply signal may be a power supply signal for powering the display driving circuit (such as a timing controller T-CON) in the display device, wherein the first power supply signal at the first power supply signal terminal generally has a voltage of 5V or 12V. The first power supply signal at the first level (for example, a high level) is being in a second status for controlling the display device (for example, the timing controller T-CON of the display device) to be turned on, and the first power supply signal at the second level (for example, a low level) is being in a first status for controlling the display device (for example, the timing controller T-CON of the display device) to be turned off. The predetermined time period may be longer than the time required for the display driving circuit in the display device to be powered on, for example, longer than the time required for the power supply voltage Vcore in the timing controller T-CON, voltage Vio at GPIO terminals, other logic voltages and the like being stabilized.
In step S120, an output signal for causing the backlight module of the display device to be turned off is generated by the first controlling circuit, in response to the first power supply signal being in the first status for controlling the display device to be turned off.
In step S130, an output signal for causing the backlight module to be turned on again after being kept in the turned off state for the predetermined time period is generated by the second controlling circuit, in response to the first power supply signal being in the second status for controlling the display device to be turned on.
For example, the first controlling circuit and the second controlling circuit may generate the output signal in a manner described in any of the embodiments with reference to
At time t1, the display device is turned off, the first power supply signal terminal VCC1 may provide the first power supply signal being in a first status, and the first power supply signal terminal VCC1 for powering the display driving circuit of the display device is at a low level. With reference to
At time t2, the display device is turned on, the first power supply signal terminal VCC1 may provide the first power supply signal being in a second status, and the first power supply signal terminal VCC1 for powering the display driving circuit of the display device is at a high level. With reference to
At time t3, the charging of the third capacitor C3 is completed, the third transistor T3 is turned off, and the level at the first outputting terminal OUT1 is no longer pulled down, so that the enabling signal terminal of the backlight module returns to a high level, causing the backlight module to be turned on. For example, the third capacitor C3 and the fourth resistor R4 are set such that the charging time D for the third capacitor C3 (i.e. a time period from time t2 to time t3) under the voltage of the first power supply signal terminal VCC1 is equal to the above-mentioned predetermined time period, which may be longer than the timed required for respective power supply voltage Vcore in the display driving circuit (for example, timing controller T-CON), the voltage at the GPIO terminal, other logic voltages and the like being stabilized after being powered. Therefore, the second controlling circuit 220 can ensure that the enabling signal terminal of the backlight module is at a low level before the powering on of the timing controller T-CON is completed, and the level at the enabling signal terminal of the backlight module is stopped to be pulled down after the powering on of the timing controller T-CON is completed, thereby enabling the backlight module to be turned on normally.
As shown in
The backlight module 1200 is electrically connected to the device for controlling backlight 1100. The backlight module 1200 may be turned on or off under the control of an output signal from the device for controlling backlight 1100.
For example, in a case where the device for controlling backlight 1100 has any of the example structures described above with reference to
Those skilled in the art would understand that the embodiments described above are all exemplary, and various modifications can be made. The structures described in the various embodiments can be freely combined without conflicts in structure or principle.
After a detailed description of the preferred embodiments of the present disclosure, those skilled in the art can clearly understand that various changes and modifications can be made without departing from the scope and spirit of the appended claims, and the embodiments of the present disclosure are not limited to the implementation of the exemplary embodiments described in the description.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201910598164.1 | Jul 2019 | CN | national |
