Patent Application
20250087172
The present disclosure relates to the field of display technologies and in particular, relates to a display device and a driving circuit thereof and a driving method.
Miniature light-emitting diodes having a size approximately less than 500 m are increasingly used significantly in the field of display due to its advantages of smaller size, ultra-high luminance and long service life. For example, they may be used as backlight sources, also known as light-emitting boards, in liquid crystal display (LCD) devices.
A display device and a driving circuit thereof and a driving method are provided.
In an aspect, a driving circuit is provided. The driving circuit has a power-line communication input pin, a data input pin and an output pin. The driving circuit includes a light emission control sub-circuit, an amplification sub-circuit and a low-grayscale control sub-circuit, wherein
Optionally, the amplification sub-circuit includes a first resistor, a second resistor, a third resistor and an amplifier, wherein
Optionally, the low-grayscale control sub-circuit includes a switching transistor, wherein
Optionally, the switching transistor is an N-type transistor.
Optionally, the driving circuit further has a ground pin, wherein the light emission control sub-circuit is further coupled to a base power source terminal and the ground pin, and configured to generate a driving signal based on the power communication signal, the address signal, a base power source signal provided by the base power source terminal, and a signal provided by the ground pin;
Optionally, the driving circuit further includes a power source providing sub-circuit, wherein
Optionally, the power source providing sub-circuit includes a plurality of stages of boost units connected in series, wherein each stage of boost unit includes: a first isolation sub-unit, a second isolation sub-unit, a first charge-discharge sub-unit, and a second charge-discharge sub-unit;
Optionally, each of the first isolation sub-unit and the second isolation sub-unit includes an isolation diode; and
Optionally, the light emission control sub-circuit, the amplification sub-circuit, the low-grayscale control sub-circuit, and the power source providing sub-circuit are integrated.
In another aspect, a driving method is provided, which is applicable to the driving circuit as described in the above aspect. The method includes:
Optionally, said generating, by the light emission control sub-circuit, the driving signal based on the power communication signal and the address signal includes:
Optionally, the number of the plurality of cycles is greater than or equal to 5.
In still another aspect, a display device is provided, the display device includes a display panel, a light-emitting board disposed on one side of the display panel, and the driving circuit as described in the above aspect, wherein
Optionally, the light-emitting board includes a plurality of light-emitting unit groups, each of the light-emitting unit groups including a plurality of light-emitting elements connected in series; and the display device includes a plurality of driving circuits in one-to-one correspondence with the plurality of light-emitting unit groups, wherein
Optionally, the light-emitting element includes a mini light-emitting diode (mini LED).
For clearer descriptions of the technical solutions in the embodiments of the present disclosure, the following briefly introduces the accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description show merely some embodiments of the present disclosure, and persons of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.
For clearer descriptions of the objectives, technical solutions and advantages of the present disclosure, the embodiments of the present disclosure are further described in detail below in combination with the accompanying drawings.
In the related art, an LCD device generally includes an LCD panel, a light-emitting board disposed on one side of the LCD panel and including a plurality of light-emitting elements, and at least one driving circuit for driving the light-emitting board to emit light. The driving circuit is coupled to negative electrodes of the light-emitting elements in the light-emitting board and configured to transmit a driving signal to cathodes of the light-emitting elements. Positive electrodes of the light-emitting elements in the light-emitting board are coupled to a power supply terminal and the light-emitting board may emit light based on the driving signal and a power supply signal provided by the power supply terminal.
However, due to limitation of factors such as process conditions and electrical properties of components, an inherent leakage current exists in the driving circuit. When the driving circuit drives the light-emitting board to enter a black-frame insertion state, once the leakage current is greater than a starting current for turning on the light-emitting element in the light-emitting board, the light-emitting board will have the phenomenon of low-luminance display, resulting in the problem of poor display of the LCD panel. The embodiments of the present disclosure provide a novel driving circuit which can solve the problem of poor display of the LCD panel.
The light emission control sub-circuit 01 is coupled (i.e., electrically connected) to the power-line communication input pin Pwr, the data input pin Di and the output pin Out. The light emission control sub-circuit 01 is configured to generate a driving signal (such as a driving current) based on a power communication signal provided by the power-line communication input pin Pwr and an address signal provided by the data input pin Di and output the driving signal through the output pin Out. The power communication signal may include a power supply voltage, such as 4.5 V.
In the embodiments of the present disclosure, in conjunction with
Optionally, the light-emitting element described in the embodiments of the present disclosure may be a mini light-emitting diode (mini LED).
Optionally, with reference to
It should be noted that in conjunction with
It should also be noted that the light emission control sub-circuit 01 may be configured to generate a pulse width modulation signal and a luminance control signal based on the power communication signal provided by the power-line communication input pin Pwr and the address signal provided by the data input pin Di, and generate the driving signal (such as the driving current) based on the pulse width modulation signal and the luminance control signal. The pulse width modulation signal may be configured to control the duty ratio of the generated driving signal, and the luminance control signal may be configured to control the amplitude of the generated driving signal, thereby adjusting the luminance of the light-emitting unit group 101. On this basis, it can be seen that if it is necessary to control the display panel to display a black picture (also known as an L0 picture), the duty ratio of the PWM signal may be adjusted to 0% to make the light-emitting board including the plurality of light-emitting unit groups 101 enter a black-frame insertion state, so that the display panel displays the L0 picture.
However, in a current display device, due to limitations of factors such as process conditions and circuit characteristics, the driving circuit 00 has a leakage current of about 5 nA in a standby state. The leakage current may be understood as a tiny current that flows through a P-N junction of a transistor in the driving circuit 00 when it is turned off. When the L0 picture is displayed, if the leakage current of the driving circuit 00 corresponding to certain light-emitting unit group 101 flows through the plurality of light-emitting elements connected in series, a leakage current loop is formed. Once the leakage current is greater than the starting current (about 2 nA) required to turn on the plurality of light-emitting elements connected in series, a positive voltage difference exists between the positive electrode (i.e. P electrode) and the negative electrode (i.e. N electrode), that is, Vp (a voltage of the positive electrode)−Vn (a voltage of the negative electrode)>0, so that the single light-emitting area where the light-emitting unit group 101 is disposed exhibits L0 low-luminance and the display panel cannot reliably display the L0 picture, but shows low-luminance display. If each of the plurality of light-emitting unit groups 101 has this leakage current loop, the display panel has the phenomenon of poor and abnormal display, such as a snowflake screen. The embodiments of the present disclosure provide a driving circuit. This circuit may change the voltage difference between the positive electrode and the negative electrode when the L0 picture is displayed, so that Vp−Vn≤0 to solve the problem of the snowflake screen.
With continued reference to
The low-grayscale control sub-circuit 03 is further coupled to an enabling control terminal L0_EN and the output pin Out. The low-grayscale control sub-circuit 03 is configured to control the on-off between the amplification sub-circuit 02 and the output pin Out based on an enabling control signal provided by the enabling control terminal L0_EN.
For example, in the embodiments of the present disclosure, when the display panel displays the L0 picture, the enabling control terminal L0_EN may be controlled to provide an enabling control signal at a first potential, and when the display panel does not display the L0 picture, the enabling control terminal L0_EN may be controlled to provide an enabling control signal at a second potential.
The low-grayscale control sub-circuit 03 may control the connection between the amplification sub-circuit 02 and the output pin Out to be turned on when a potential of the enabling control signal provided by the enabling control terminal L0_EN is the first potential, that is, when the display panel displays the L0 picture. In this case, the reference power source signal amplified by the amplification sub-circuit 02 may be transmitted to the output pin Out. As the voltage of the amplified reference power source signal is greater than the voltage of the power supply signal provided by the power supply terminal VLED, in combination with the descriptions in the above embodiments, it can be seen that in this case, the voltage Vn transmitted to the negative electrodes of the plurality of light-emitting elements connected in series in the light-emitting unit group 101 is greater than or equal to the voltage Vp of the positive electrodes thereof, that is, Vp−Vn≤0. In this way, when the L0 picture is displayed, it is possible to avoid the situation that the light-emitting unit group 101 is turned on as the leakage current flows through the plurality of light-emitting elements connected in series, thereby avoiding the problem of the snowflake screen.
In addition, the low-grayscale control sub-circuit 03 may control the connection between the amplification sub-circuit 02 and the output pin Out to be turned off when the potential of the enabling control signal provided by the enabling control terminal L0_EN is the second potential, that is, when the display panel does not display the L0 picture. In this case, the reference power source signal amplified by the amplification sub-circuit 02 is not transmitted to the output pin Out and the driving signal generated by the light emission control sub-circuit 01 may be reliably output through the output pin Out, so that the plurality of light-emitting elements connected in series in the light-emitting unit group 101 can reliably emit light. On this basis, the amplification sub-circuit 02 and the low-grayscale control sub-circuit 03 may be collectively referred to as a high-voltage injection control loop.
Optionally, in the embodiments of the present disclosure, the first potential may be an effective potential, the second potential may be an ineffective potential, and the first potential may be a high potential relative to the second potential. Certainly, in some other embodiments, the first potential may also be a low potential relative to the second potential for example. It should be noted that the first potential and the second potential only represent that the potential of the signal has two state quantities, instead of representing that the first potential or the second potential has a specific value.
In summary, the embodiments of the present disclosure provide a driving circuit. The driving circuit includes the light emission control sub-circuit, the amplification sub-circuit and the low-grayscale control sub-circuit. The light emission control sub-circuit may generate the driving signal and output the same from the output pin, so that the light-emitting unit group coupled to the output pin emits light based on the driving signal and the power supply signal provided by the power supply terminal. The amplification sub-circuit may amplify the reference power source signal provided by the reference power source terminal to have a voltage not less than the potential of the power supply signal and transmit the amplified reference power source signal to the low-grayscale control sub-circuit. The low-grayscale control sub-circuit may control an on-off between the amplification sub-circuit and the output pin under the control of the enabling control terminal. In this way, by flexibly setting the signal provided by the enabling control terminal, when the light-emitting board including the light-emitting unit group enters the black-frame insertion state, the amplified reference power source signal can be further transmitted to the light-emitting unit group, so that the voltage of the first electrode of the light-emitting unit group is greater than the voltage of the second electrode thereof and the light-emitting unit group cannot emit light. Thus, the light-emitting board is prevented from having the phenomenon of low-luminance display and it can be ensured that the display panel has a relatively good display effect.
In conjunction with
On this basis, it can be seen that in an example of the embodiments of the present disclosure, the reference power source terminal Vf1 may be used as the base power source terminal, and the second power source terminal V2 may be coupled to the ground pin GND.
It should be noted that in the embodiments of the present disclosure, the driving circuit 00 may operate at various modes which at least include an addressing mode, a configuration mode and an operating mode. During the addressing mode, each driving circuit 00 may be assigned a unique address and the address may be configured to broadcast additional commands and data in the configuration mode and the operating mode. During the configuration mode, the driving circuit 00 may be configured through one or more operating parameters (such as an overcurrent threshold, an overvoltage threshold, a clock-frequency-dividing ratio, and/or conversion rate control). During the operating mode, control data may be provided to the driving circuit 00, which enables the driving circuit 00 to control a current to the light-emitting unit group 101, thereby controlling the luminance of light emitted by the light-emitting unit group 101. In other embodiments, operating modes of the display device may include additional, less or different operating modes. For example, the operating modes may include an initialization mode and a shutdown mode.
The voltage regulator 011 may be coupled to the power-line communication input pin Pwr and may further be coupled to the physical layer Rx_PHY 012 and the low-dropout regulator LDO_D 013. The low-dropout regulator LDO_D 013 may further be coupled to the OSC 014. The low-dropout regulator LDO_D, the OSC 014 and the physical layer Rx_PHY 012 may all be coupled to the control logic unit 015. The control logic unit 015 may further be coupled to the address driver 016, the dimming and control signal generation unit 017 and the luminance control unit 018. The address driver 016 may further be coupled to a first electrode of the switching tube K1 and the first electrode of the switching tube K1 may further be coupled to the output pin Out. The dimming and control signal generation unit 017 may further be coupled to a gate of the switching tube K1. A second electrode of the switching tube K1 may be coupled to the luminance control unit 018. The luminance control unit 018 may be coupled to the ground pin GND.
On the basis of the above coupling, the voltage regulator 011 may demodulate the power communication signal received from the power-line communication input pin Pwr into a power supply voltage and digital data. The power supply voltage represents a DC component of the power communication signal, and the digital data represents a modulation component of the power communication signal. In an exemplary embodiment, the voltage regulator 011 includes a first-order RC filter following an active follower. The digital data may be provided to the physical layer Rx_PHY 012 connected between the voltage regulator 011 and the control logic unit 015. The physical layer Rx_PHY 012 may provide a connection with the maximum bandwidth of 2 MHz with 36 cascades. The power supply voltage may be provided to the low-dropout regulator LDO_D 013. The low-dropout regulator LDO_D 013 may convert the power supply voltage to a stable DC voltage for providing power for the oscillator OSC 014, the control logic unit 015 and other components, and the low-dropout regulator LDO_D 013 may decrease the voltage gradually. In an exemplary embodiment, the stable DC voltage may be 1.8V. The oscillator OSC 014 may also provide a clock signal DCLK. In an exemplary embodiment, the maximum frequency of the clock signal DCLK may be about 10.7 MHz.
The control logic unit 015 may receive the digital data from the physical layer Rx_PHY 012, the DC voltage from the low-dropout regulator LDO_D 013, and the clock signal DCLK from the oscillator OSC 014. Depending on the operating mode of the display device, the control logic unit 015 may output an enabling signal En and an incremental data signal Inc_data to the address driver 016, the maximum current signal Max Current to the luminance control unit 018, and a clock selection signal PWM CLK_sel to the dimming and control signal generation unit 017. For example, during the addressing mode, the logic control unit 015 may activate the enabling signal En to start the address driver 016. The address driver 016 receives an incoming address signal via the data input pin Di and stores the address, and the incremental data signal Inc_data representing an outgoing address is provided to the address driver 016. In the case that the enabling signal En is activated during the addressing mode, the address driver 016 may cache the incremented data signal Inc_data to the output pin Out. The control logic unit 015 may control the dimming and control signal generation unit 017 to transmit a turn-off signal to the switching tube K1 during the addressing mode so as to reliably turn off the transistor K1, thereby effectively blocking a current path from the light-emitting element.
During the operating mode and the configuration mode, the control logic unit 015 may deactivate the enabling signal En and the output of the address driver 360 may be tristate output so as to effectively decouple it from the output pin Out. During the operating mode, the clock selection signal PWM CLK_sel may specify a duty ratio used by the dimming and control signal generation unit 017 to control the PWM signal. Based on the selected duty ratio, the dimming and control signal generation unit 017 may control the timing of a conduction (turn-on) state and a non-conduction (turn-off) state of the transistor K1. During the conduction state of the transistor K1, a current path from the output pin Out to the ground pin GND through the transistor K1 is established. In addition, the luminance control unit 018 may collect driver currents through the light-emitting unit group 101. During the non-conduction state of the transistor K1, the current path is interrupted to block the current from flowing through the light-emitting unit group 101. When the transistor M1 is in the conduction state, the luminance control unit 018 may receive the maximum current signal Max Current from the control logic unit 015 and control a level of the current flowing through the light-emitting unit group 101. During the operating mode, the control logic unit 015 may control the duty ratio of the dimming and control signal generation unit 017 and the maximum current Max Current of the luminance control unit 018 so as to set the light-emitting unit group 101 to have the desired luminance.
One end of the first resistor R1 may be coupled to the reference power source terminal Vf1 and the other end of the first resistor R1 may be coupled to a positive input terminal of the amplifier U1.
One end of the second resistor R2 may be coupled to a negative input terminal of the amplifier U1 and the other end of the second resistor R2 may be coupled to an output terminal of the amplifier U1.
One end of the third resistor R3 may be coupled to the negative input terminal of the amplifier U1 and the other end of the third resistor R3 may be coupled to the second power source terminal V2.
The output terminal of the amplifier Ulmay be coupled to the low-grayscale control sub-circuit 03 and the amplifier U1 may further be coupled to the first power source terminal V1 and the second power source terminal V2.
In an exemplary embodiment, a benchmark voltage in the light emission control sub-circuit 01 is generally 2.5 V, that is, a potential of the base power source signal provided by the base power source terminal Vf2 is 2.5 V. Correspondingly, it can be seen that a potential of the reference power source signal provided by the reference power source terminal Vf1 used as the base power source terminal Vf2 may also be 2.5 V.
On the basis of
where r2 refers to a resistance value of the second resistor R2, r3 refers to a resistance value of the third resistor R3, and Vf10 refers to the potential of the reference power source signal provided by the reference power source terminal Vf1. Based on the above formula (1), it can be seen that the required amplification function may be achieved by flexibly setting the resistance values of the second resistor R2 and the third resistor R3.
For example, assuming that the potential of the power supply signal transmitted by the power supply terminal VLED to the positive electrodes (i.e., P electrodes) of the plurality of the light-emitting elements connected in series in the light-emitting unit group 101 is 25V and the starting current of the plurality of the light-emitting elements connected in series in the light-emitting unit group 101 is 2 nA, in order to make the voltage of the negative electrode (N electrode) greater than or equal to the voltage of the P electrode, the potential transmitted to the output pin Out may increase to be greater than or equal to 25V. Again, assuming that the potential of the reference power source signal is 2.5 V, it can be seen that the amplification factor of the amplification sub-circuit 02 needs to be 10 times. That is, by setting the resistance value of the second resistor R2 to 9 times the resistance value of the third resistor R3, the amplification sub-circuit 02 may reliably amplify the reference power source signal from 2.5V to 25V. By increasing the resistance value of the second resistor R2 continuously or simultaneously increasing the resistance value of the second resistor R2 and the resistance value of the third resistor R3, or decreasing the resistance value of the third resistor R3, the amplification sub-circuit 02 may amplify the reference power source signal from 2.5V to 25V. In this way, it can be seen that the voltage difference between the P electrode and the N electrode may be less than or equal to 0, that is, Vp−Vn≤0. Thus, the plurality of light-emitting elements connected in series in the light-emitting unit group 101 cannot emit light, thereby solving the problem of the snowflake screen of the display panel.
With continued reference to
A control electrode of the switching transistor T1 may be coupled to the enabling control terminal L0_EN, a first electrode of the switching transistor T1 may be coupled to the amplification sub-circuit 02, and a second electrode of the switching transistor T1 may be coupled to the output pin Out. For example, the first electrode of the switching transistor T1 may be coupled to the output terminal of the amplifier U1.
Optionally, the transistor may be a thin film transistor or a field-effect transistor or other devices having the same properties. Since a source and a drain of the transistor are symmetrical, the source and the drain of the transistor are interchangeable. Correspondingly, it can be seen that in the first electrode and the second electrode of the transistor described in the embodiments of the present disclosure, one electrode may be the source and the other electrode may be the drain. In addition, according to the form in the figure, it is specified that a middle terminal of the transistor is the control electrode, which may also be called a gate. Furthermore, the transistor used in the embodiments of the present disclosure may be either a P-type transistor or an N-type transistor. The P-type transistor is turned on when the gate is at a low potential and is turned off when the gate is at a high potential, and the N-type transistor is turned on when the gate is at the high potential and is turned off when the gate is at the low potential.
For example, the switching transistor T1 described in the embodiments of the present disclosure may be the N-type transistor. Correspondingly, as described in the above embodiments, the first potential of the enabling control signal may be the high potential relative to the second potential. Certainly, if the switching transistor T1 is the P-type transistor, the first potential of the enabling control signal may be the low potential relative to the second potential. The embodiments of the present disclosure are described by taking that the switching transistor T1 is the N-type transistor as an example.
By taking that the switching transistor T1 is the N-type transistor as an example, in conjunction with
It should be noted that according to the working characteristics of the amplifier U1, it can be seen that it can be ensured that the reference power source signal provided by the reference power source terminal Vf1 is reliably amplified only when the voltage of the first power source signal provided by the first power source terminal V1 is high enough. At present, the power supply voltage inside the driving circuit 00, i.e., the maximum voltage Vpwr provided by the power-line communication input pin Pwr, is generally about 4.5V, and if the Vpwr of about 4.5V is directly transmitted to the first power source terminal V1 (that is, it is set that the first power source terminal V1 is directly coupled to the power-line communication input pin Pwr) as the first power source signal, it can be seen that the amplification capacity of the amplification sub-circuit 02 is relatively low and thus the amplification sub-circuit 02 cannot reliably amplify the reference power source signal to a potential greater than the potential (such as 25V) of the power supply signal provided by the power supply terminal. For this purpose, with reference to the structural schematic diagram of another driving circuit shown in
The power source providing sub-circuit 04 may be coupled to the power-line communication input pin Pwr, a signal supply terminal Pwm and the first power source terminal V1. The power source providing sub-circuit 04 may be configured to transmit the first power source signal to the first power source terminal V1 based on the power communication signal and the PWM signal.
A signal provided by the signal supply terminal Pwm may be a pulse width modulation signal. The voltage of the first power source signal is not less than (i.e., greater than or equal to) the voltage of the amplified reference power source signal. That is, the power source providing sub-circuit 04 may boost the potential based on the power communication signal provided by the power-line communication input pin Pwr and the pulse width modulation signal provided by the signal supply terminal Pwm and transmit the boosted signal to the first power source terminal V1. Correspondingly, the power source providing sub-circuit 04 may also be called as a boost circuit.
For example, assuming that as described in the above embodiments, the voltage transmitted to the low-grayscale control sub-circuit 03 by the amplification circuit 02 is 25 V, the voltage of the first power source signal transmitted to the first power source terminal V1 by the power source providing sub-circuit 04 may be greater than or equal to 25 V, thereby ensuring that the amplification sub-circuit 02 reliably amplifies the reference power source signal of about 2.5 V to the required 25 V based on the first power source signal.
Optionally, on the basis of the light emission control sub-circuit 01 shown in
In each stage of boost unit 041, an output terminal of the first isolation sub-unit 0411 is coupled to one end of the first charge-discharge sub-unit 0413 and an input terminal of the second isolation sub-unit 0412, an output terminal of the second isolation sub-unit 0412 is coupled to one end of the second charge-discharge sub-unit 0414, the other end of the first charge-discharge sub-unit 0413 is coupled to the signal supply terminal Pwm, and the other end of the second charge-discharge sub-unit 0414 is grounded.
An input terminal of the first isolation sub-unit 0411 in each other stage of boost unit 041 except the first-stage boost unit 041 is coupled to the output terminal of the second isolation sub-unit 0412 in a previous-stage boost unit 041, an input terminal of the first isolation sub-unit 0411 in the first-stage boost unit 041 is coupled to the power-line communication input pin Pwr, and the output terminal of the second isolation sub-unit 0412 in the last-stage boost unit 041 is further coupled to the first power source terminal V1.
By taking
Optionally, as described in the above embodiments, it can be seen that the potential Vpwr of the power communication signal is generally 4.5 V, and the minimum amplitude and the maximum amplitude of the potential Vpwm of the pulse width modulation signal provided by the signal supply terminal Pwm are generally 0 and 4.5 V respectively, that is, the pulse width modulation signal may be a high-frequency square-wave voltage signal ranging from 0 to 4.5 V. On this basis, in conjunction with the circuit shown in
For each stage of boost unit 041, when the potential Vpwm of the pulse width modulation signal is the low potential of 0, the power-line communication input pin Pwr may charge the charge-discharge capacitor C1 included in the first charge-discharge sub-unit 0413 through the isolation diode D1 included in the first isolation sub-unit 0411, and the voltage at two terminals of the charge-discharge capacitor C1 included in the first charge-discharge sub-unit 0413 is positive at the top and negative at the bottom and is 4.5V. When the potential Vpwm of the pulse width modulation signal is a high potential of 4.5V, the potential Vpwr of the received power communication signal and the potential Vpwm of the pulse-width modulation signal may be superimposed and a charge-discharge capacitor C1 included in the second charge-discharge sub-unit 0414 may be charged through the isolation diode D1 included in the second isolation sub-unit 0412. If the conduction voltage drop of the isolation diode D1 is ignored, it can be seen that in this case, the voltage at two terminals of the charge-discharge capacitor C1 included in the second charge-discharge sub-unit 0414 is 4.5V+4.5V=9V. In this way, the voltage doubling function is realized. If higher voltages are required, it can be seen that as shown in
Optionally, in the embodiments of the present disclosure, the light emission control sub-circuit 01, the amplification sub-circuit 02, the low-grayscale control sub-circuit 03 and the power source providing sub-circuit 04 may be integrated. That is, they may be integrally disposed in one IC. In other words, compared with related technologies, the driving circuit 00 provided by the embodiments of the present disclosure may further include the amplification sub-circuit 02, the low-grayscale control sub-circuit 03 and the power source providing sub-circuit 04 in addition to the light emission control sub-circuit 01.
In conjunction with the above descriptions, it can be seen that in the embodiments of the present disclosure, when the display panel displays the L0 picture, the voltage which is greater than or equal to the voltage of the power supply signal provided by the power supply terminal VLED is input into the output pin Out of the light emission control sub-circuit 01, so that a positive voltage difference between the N and P electrodes of the plurality of light-emitting elements connected in series of the light-emitting unit group 101 is less than or equal to 0. Thus, the plurality of light-emitting elements connected in series cannot emit light, thereby solving the problem of the snowflake screen. In addition, it can also solve the problem of low-luminance display of the single light-emitting area caused by low impedance on a printed circuit board (FOB) on board, and the FOB may refer to a circuit board provided with the above light-emitting board 10 and its driving circuit 00.
In summary, the embodiments of the present disclosure provide a driving circuit. The driving circuit includes the light emission control sub-circuit, the amplification sub-circuit and the low-grayscale control sub-circuit. The light emission control sub-circuit may generate the driving signal and output the same from the output pin, so that the light-emitting unit group coupled to the output pin emits light based on the driving signal and the power supply signal provided by the power supply terminal. The amplification sub-circuit may amplify the reference power source signal provided by the reference power source terminal to have a voltage not less than the voltage of the power supply signal and transmit the amplified reference power source signal to the low-grayscale control sub-circuit. The low-grayscale control sub-circuit may control an on-off between the amplification sub-circuit and the output pin under the control of the enabling control terminal. In this way, by flexibly setting the signal provided by the enabling control terminal, when the light-emitting board including the light-emitting unit group enters the black-frame insertion state, the amplified reference power source signal can be further transmitted to the light-emitting unit group, so that the voltage of the first electrode of the light-emitting unit group is greater than the voltage of the second electrode thereof and the light-emitting unit group cannot emit light. Thus, the light-emitting board is prevented from having the phenomenon of low-luminance display and it can be ensured that the display panel has a relatively good display effect.
In step 1201, a power communication signal is provided to a power-line communication input pin and an address signal is provided to a data input pin, and a light emission control sub-circuit generates a driving signal based on the power communication signal and the address signal, and outputs the driving signal through an output pin.
In step 1202, a reference power source signal is provided to a reference power source terminal, a first power source signal is provided to a first power source terminal, a second power source signal is provided to a second power source terminal, and an amplification sub-circuit amplifies the reference power source signal provided by the reference power source terminal based on the first power source signal and the second power source signal, and transmits the amplified reference power source signal to a low-grayscale control sub-circuit.
In step 1203, whether to control a light-emitting board including a light-emitting unit group to enter a black-frame insertion state or not is determined.
In step 1204, if it is determined that the light-emitting board is controlled to enter the black-frame insertion state, an enabling control signal at a first potential is provided to an enabling control terminal, and the low-grayscale control sub-circuit controls, in response to the enabling control signal at the first potential, a connection between the amplification sub-circuit and the output pin to be turned on, so that the amplified reference power source signal is transmitted to the output pin.
In step 1205, if it is determined that the light-emitting board is not controlled to enter the black-frame insertion state, an enabling control signal at a second potential is provided to the enabling control end, and the low-grayscale control sub-circuit controls, in response to the enabling control signal at the second potential, the connection between the amplification sub-circuit and the output pin to be turned off.
Optionally, as described in the above embodiments, step 1201 above that the light emission control sub-circuit generates the driving signal based on the power communication signal and the address signal may include: the light emission control sub-circuit generates a pulse width signal and a luminance control signal based on the power communication signal and the address signal, and generates the driving signal based on the pulse width modulation signal and the luminance control signal. In addition, with reference to the time sequence diagram of the signal terminal shown in
if the pulse width modulation signal generated by the light emission control sub-circuit is at the second potential within a plurality of cycles of the clock signal DCLK, that the light-emitting board including the light-emitting unit group is controlled to enter the black-frame insertion state is determined. For example, the number of the plurality of cycles may be greater than or equal to 5. That is, if the pulse width modulation signal generated by the light emission control sub-circuit is at the second potential within five or more cycles of the clock signal DCLK, that the light-emitting board including the light-emitting unit group enters the black-frame insertion state may be determined. The number of the plurality of cycles shown in
By taking that the switching transistor T1 shown in
In summary, the embodiments of the present disclosure provide a driving method. In this method, the light emission control sub-circuit may generate the driving signal and output the same from the output pin, so that the light-emitting unit group coupled to the output pin emits light based on the driving signal and the power supply signal provided by the power supply terminal coupled to the positive electrode. The amplification sub-circuit may amplify the reference power source signal provided by the reference power source terminal to be greater than or equal to the voltage of the power supply signal and transmit the amplified reference power source signal to the low-grayscale control sub-circuit. The low-grayscale control sub-circuit may control a connection between the amplification sub-circuit and the output pin to be turned on when the light-emitting board including the light-emitting unit group enters the black-frame insertion state, so that the reference power source signal with the amplified potential may be further transmitted to the light-emitting unit group, the voltage of a first electrode of the light-emitting unit group is greater than the voltage of a second electrode thereof and hence the light-emitting unit group cannot emit light. Thus, the light-emitting board is prevented from having the phenomenon of low-luminance display and it can be ensured that the display panel has a relatively good display effect.
It should be noted that specific control modes of above respective steps may refer to those described at the device side and are not repeated at the method side.
It should be noted that in an LCD device, that the light-emitting board 10 is disposed on one side of the display panel M1 generally means that the light-emitting board 10 is disposed on a non-display side of the display panel M1. The light-emitting board 10 may be used as a backlight source of the LCD device to provide backlight for the LCD device, so that the LCD device displays normally.
In conjunction with
In addition, with continued reference to
The output pin Out of each of the driving circuits may be coupled to first electrodes (such as negative electrodes) of the plurality of light-emitting elements L connected in series in a corresponding light-emitting unit group 101, second electrodes (such as positive electrodes) of the plurality of light-emitting elements L connected in series in each light-emitting unit group 101 may also be coupled to a power supply terminal VLED, and the plurality of light-emitting elements L may be configured to emit light based on a driving signal output from the output pin Out of the driving circuit 00 and a power supply signal provided by the power supply terminal VLED.
Optionally, as described in the above embodiments, it can further be seen that the light-emitting element L described in the embodiments of the present disclosure may include a mini light-emitting diode (mini LED). On this basis,
In conjunction with the schematic product diagram of the light-emitting board 10 shown in
Optionally, the display device may be any product or component having a display function, such as an LCD display device, electronic paper, a mobile phone, a tablet computer, a television, a display, a laptop computer or a navigator.
It should be understood that the terms used in the embodiments of the present disclosure are merely intended to explain the embodiments of the present disclosure, instead of limiting the present disclosure. Unless defined otherwise, the technical terms or scientific terms used in the embodiments of the present disclosure shall have the general meaning understood by persons of ordinary skill in the art. For example, the terms “first”, “second”, “third” and similar terms used in the embodiments of the present disclosure do not denote any order, quantity, or importance, and are merely used to distinguish between different components.
Likewise, the term “one” or “a/an” and similar terms denote at least one, instead of limiting the quantity.
The word “comprise” or “include” and similar terms mean that the element or object appearing before the word “comprise” or “include” covers the listed elements, objects and equivalents thereof appearing after the word “comprise” or “include”, without excluding other elements or objects.
The term “connection” or “connected” and similar terms are not limited to physical or mechanical connection, and may include electrical connection and the connection may be direct or indirect.
The terms “upper”, “lower”, “left”, right” and the like are used to indicate a relative positional relationship. When an absolute position of the described object changes, the relative positional relationship is also changed accordingly.
The above descriptions are merely optional embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements and the like made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure.
This application is a US national stage of international application No. PCT/CN2022/133572, filed on Nov. 22, 2022, the disclosure of which is herein incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/133572 | 11/22/2022 | WO |
