A driving circuit, method and display device

Abstract

The present application discloses a driving circuit, method and display device, wherein the driving circuit includes a light-emitting element, a control module and a driving module; the driving module is respectively connected to the control module and the light-emitting element, the control module is used to output a control signal according to an input signal; the driving module is used to drive the light-emitting element to continuously light up according to the control signal; the present application can alleviate the flicker problem in the current dimming method.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a driving circuit, method and display device. Background Art

[0002] The backlight source currently used in televisions is an LED light source. In order to obtain a good display effect, the working current of the LED is not fixed, and the LED dimming technology needs to be used for dimming processing.

[0003] At present, in order to achieve a larger dimming range and a more consistent color temperature curve, PWM dimming is usually selected to obtain better electrical performance. However, due to the characteristics of PWM dimming, even a higher PWM frequency can cause damage to the human eye due to the inherent stroboscopic effect. Summary of the invention

[0004] The present application provides a driving circuit, method and display device, which can alleviate the flicker problem existing in the current PWM dimming method.

[0005] The present application provides a driving circuit, the driving circuit comprising:

[0006] Light emitting element;

[0007] A control module, the control module is used to output a control signal according to an input signal;

[0008] The driving module is connected to the control module and the light-emitting element respectively, and is used to drive the light-emitting element to light up continuously according to the control signal.

[0009] In some embodiments, the driving circuit, the driving module includes a switch control unit, a first switch unit, a second switch unit, a first driving unit, and a second driving unit;

[0010] The switch control unit is respectively connected to the control module, the control end of the first switch unit and the control end of the second switch unit, the first connection end of the first switch unit is connected to the light-emitting element, the second connection end of the first switch unit is connected to the first driving unit, the first connection end of the second switch unit is connected to the light-emitting element, and the second connection end of the second switch unit is connected to the second driving unit.

[0011] In the driving circuit of some embodiments, the first switching unit includes a first switching tube, a first end of the first switching tube is connected to the first control end of the switching control unit, a second end of the first switching tube is connected to the output end of the light-emitting element, and a third end of the first switching tube is connected to the first driving unit.

[0012] In the driving circuit of some embodiments, the second switch unit includes a second switch tube, a first end of the second switch tube is connected to the second control end of the switch control unit, a second end of the second switch tube is connected to the output end of the light-emitting element, and a third end of the second switch tube is connected to the second driving unit.

[0013] In some embodiments of the driving circuit, the switch control unit includes a trigger, the input end of the trigger is connected to the control module, the first output end of the trigger is connected to the first end of the first switch tube, and the second output end of the trigger is connected to the first end of the second switch tube.

[0014] In some embodiments of the driving circuit, the switch control unit includes a signal processor, the input end of the signal processor is connected to the control module, the first output end of the signal processor is connected to the first end of the first switch tube, and the second output end of the signal processor is connected to the first end of the second switch tube.

[0015] In the driving circuit of some embodiments, the control signal includes a first control signal, a second control signal and a pulse width modulation signal;

[0016] The switch control unit is used for controlling the first switch unit and the second switch unit to be alternately turned on according to the pulse width modulation signal;

[0017] The first driving unit is used to provide a first current to the light emitting element according to a first control signal;

[0018] The second driving unit is used for providing a second current to the light emitting element according to a second control signal.

[0019] In the driving circuit of some embodiments, the control signal includes a first control signal, a second control signal and a pulse width modulation signal;

[0020] The switch control unit is used to control the first switch unit to be continuously turned on and the second switch unit to be alternately turned on and off according to the pulse width modulation signal;

[0021] The first driving unit is used to provide a first current to the light emitting element according to a first control signal;

[0022] The second driving unit is used for providing a second current to the light emitting element according to a second control signal.

[0023] In the driving circuit of some embodiments, the first current and the second current each include a plurality of different current values.

[0024] The embodiment of the present application further provides a driving method, which is applied to the driving circuit as described above, and the driving method includes:

[0025] Obtaining an input signal and outputting a control signal according to the input signal;

[0026] The light-emitting element is driven to light up continuously according to the control signal.

[0027] In the driving method of some embodiments, the control signal includes a first control signal, a second control signal and a pulse width modulation signal, and driving the light-emitting element to continuously light up according to the control signal includes:

[0028] Controlling the first switch unit and the second switch unit to be alternately turned on according to the pulse width modulation signal;

[0029] The first driving unit is controlled according to the first control signal to provide a first current to the light emitting element, and the second driving unit is controlled according to the second control signal to provide a second current to the light emitting element.

[0030] In the driving method of some embodiments, the control signal includes a first control signal, a second control signal and a pulse width modulation signal, and driving the light-emitting element to continuously light up according to the control signal includes:

[0031] Controlling the first switch unit to be continuously turned on and the second switch unit to be alternately turned on and off according to the pulse width modulation signal;

[0032] The first driving unit is controlled according to the first control signal to provide a first current to the light emitting element, and the second driving unit is controlled according to the second control signal to provide a second current to the light emitting element.

[0033] An embodiment of the present application further provides a display device, which includes the driving circuit as described above.

[0034] The present application provides a driving circuit, method and display device, wherein the driving circuit controls the light-emitting element to be in a continuously lit state according to a control signal through a driving module. Compared with the original PWM dimming process in which the light-emitting element is controlled to alternately light up and off according to a PWM signal, the stroboscopic problem of the light-emitting element in the PWM dimming method can be alleviated. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0036] Figure 1 This is a structural block diagram of a driving circuit provided in an embodiment of the present application.

[0037] Figure 2 This is a structural block diagram of a driving module in a driving circuit provided in an embodiment of the present application.

[0038] Figure 3 This is a structural block diagram of a first embodiment of a switch control unit in a drive circuit provided in an embodiment of the present application.

[0039] Figure 4 This is a waveform diagram of the first switching signal and the second switching signal in the driving circuit provided in an embodiment of the present application.

[0040] Figure 5 This is a waveform diagram of the combined first switching signal and the second switching signal in the driving circuit provided in an embodiment of the present application.

[0041] Figure 6 This is a circuit diagram of the first embodiment of the driving circuit provided in the embodiments of the present application.

[0042] Figure 7 This is a circuit diagram of the second embodiment of the driving circuit provided in the embodiments of the present application.

[0043] Figure 8 A flowchart of a driving method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of technical features indicated. The features specified as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0046] See also Figure 1 This embodiment provides a driving circuit, which includes a light-emitting element 10, a control module 20 and a driving module 30; the light-emitting element 10 is connected in series to a first power supply terminal (such as Figure 1 V1 terminal in the figure) and the second power supply terminal (such as Figure 1 The driving module 30 is connected to the control module 20 and the light-emitting element 10 respectively; the control module is used to output a control signal according to an input signal; and the driving module is used to drive the light-emitting element to light up continuously according to the control signal. Compared with the original PWM dimming process in which the light-emitting element is controlled to light up and turn off alternately according to the PWM signal, the flicker problem of the light-emitting element in the PWM dimming method can be alleviated.

[0047] See also Figure 2In some embodiments, the driving module 30 includes a switch control unit 31, a first switch unit 32, a second switch unit 33, a first driving unit 34 and a second driving unit 35; the switch control unit 31 is respectively connected to the control module 20, the control end of the first switch unit 32 and the control end of the second switch unit 33, the first connection end of the first switch unit 32 is connected to the light-emitting element 10, the second connection end of the first switch unit 32 is connected to the first driving unit 34, the first connection end of the second switch unit 33 is connected to the light-emitting element 10, and the second connection end of the second switch unit 33 is connected to the second driving unit 35; the first driving unit 34 is also connected to the second power supply end, and the second driving unit 35 is also connected to the second power supply end.

[0048] Among them, the control signal includes a first control signal, a second control signal and a pulse width modulation signal; the switch control unit 31 is used to control the first switch unit 32 and the second switch unit 33 to be alternately turned on according to the pulse width modulation signal; the first drive unit 34 is used to provide a first current to the light-emitting element 10 according to the first control signal; the second drive unit 35 is used to provide a second current to the light-emitting element 10 according to the second control signal.

[0049] In this embodiment, the pulse width modulation signal has an alternating first level signal (such as a high level signal) and a second level signal (such as a low level signal). When the pulse width modulation signal is a first level signal, the switch control unit 31 outputs a first switching signal according to the first level signal to control the first switch unit 32 to be turned on. At this time, the first driving unit 34 provides a first current to the light-emitting element 10, so that the light-emitting element 10 is lit; when the pulse width modulation signal is a second level signal, the switch control unit 31 outputs a second switching signal according to the second level signal to control the second switch unit 33 to be turned on. At this time, the second driving unit 35 provides a second current to the light-emitting element 10, so that the light-emitting element 10 is lit. Compared with the original PWM dimming process, the first level signal of the PWM signal controls the light-emitting element 10 to be lit, and the second level signal of the PWM signal controls the light-emitting element 10 to be turned off. The present application can ensure that the light-emitting element 10 is in a lit state when the first level signal and the second level signal come, thereby alleviating the flicker problem of the light-emitting element 10 in the PWM dimming mode.

[0050] See also Figure 3As an embodiment, the first switch unit 32 includes a first switch tube 321, and the second switch unit 33 includes a second switch tube 331. The first end of the first switch tube 321 is connected to the first control end of the switch control unit 31, the second end of the first switch tube 321 is connected to the output end of the light-emitting element 10, and the third end of the first switch tube 321 is connected to the first driving unit 34; the first end of the second switch tube 331 is connected to the second control end of the switch control unit 31, the second end of the second switch tube 331 is connected to the output end of the light-emitting element 10, and the third end of the second switch tube 331 is connected to the second driving unit 35.

[0051] When the switch control unit 31 outputs a first switching signal, the first switch tube 321 is turned on, the second switch tube 331 is turned off, the light-emitting element 10 is connected to the first driving unit 34 to form a path, and the light-emitting element 10 is lit; when the switch control unit 31 outputs a second switching signal, the first switch tube 321 is turned off, the second switch tube 331 is turned on, the light-emitting element 10 is connected to the second driving unit 35 to form a path, and the light-emitting element 10 is lit.

[0052] As an embodiment, the switch control unit 31 includes a trigger 311, the input end of the trigger 311 is connected to the control module 20, the first output end of the trigger 311 is connected to the first end of the first switch tube 321, and the second output end of the trigger 311 is connected to the first end of the second switch tube 331; the trigger 311 in this embodiment receives the pulse width modulation signal output by the control module 20, and outputs two switching signals according to the pulse width modulation signal. Among them, the waveform diagram of the first switching signal is as follows Figure 4 As shown, the corresponding amplitude is U1. When the PWM signal is a first level signal, the corresponding light emitting element 10 is connected to the first driving unit 34, and the corresponding current is the first current I1. The waveform of the second switching signal is as shown in Figure 4 As shown, the corresponding amplitude is U2. When the PWM signal is a second level signal, the corresponding light emitting element 10 is connected to the second driving unit 35, and the corresponding current is the second current I2. If the waveform diagram of the first switching signal and the waveform diagram of the second switching signal are synthesized, the following is obtained: Figure 5 Then, the current in the driving circuit in this embodiment, i.e., the target current of the light emitting element 10, is I= I1*D+I2*(1-D), where D is the duty cycle of the pulse width modulation signal output by the controller. In this embodiment, the first current and the second current are related to the target current of the light emitting element 10.

[0053] As an embodiment, the first current and the second current each include a plurality of different current values. Specifically, the first drive unit 34 includes a first controllable current source, and the second drive unit 35 includes a second controllable current source. Correspondingly, the control module 20 can set the current gear of the first controllable current source and the second controllable current source according to the target current of the light-emitting element 10. For example, the first controllable current source and the second controllable current source each include 16 current gears, and the currents of the 16 gears increase in sequence and the increment is 1mA. If the target current of the light-emitting element 10 is 10.5mA, the duty cycle D can be set to 50%, the current gear of the first controllable current source is 10mA corresponding to the 10th gear, and the current gear of the second controllable current source is 11mA corresponding to the 11th gear, then the target current I of the light-emitting element 10=10mA*D+11mA*(1-D).

[0054] In other embodiments, the switch control unit 31 is used to output a first switch control signal and a second switch control signal according to a pulse width modulation signal. In this embodiment, the first switch control signal is a high level signal, and the second switch control signal is a pulse width modulation signal, and the corresponding pulse width modulation signal includes alternating high level signals and low level signals. That is, the switch control unit 31 in this embodiment outputs two switch control signals according to the pulse width modulation signal, one of which is a high level signal and the other is also a pulse width modulation signal.

[0055] Among them, the first switch unit 32 is continuously turned on according to the first switch control signal, and the first drive unit 34 provides the first current to the light-emitting element 10 according to the first control signal, so that the light-emitting diode is continuously lit; the second switch unit 33 is alternately turned on or off according to the second switch control signal, and when the second switch unit 33 is turned on, the second drive unit 35 provides the second current to the light-emitting element 10 according to the second control signal, so that the light-emitting element 10 reaches the target current. Compared with the original PWM dimming process in which the light-emitting element is controlled to alternately light up and off according to the PWM signal, the present application can ensure that the light-emitting element 10 is always in the lit state, thereby alleviating the flicker problem of the light-emitting element 10 in the PWM dimming method.

[0056] As an embodiment, the first switch tube 321 and the second switch tube 331 in this embodiment can both be MOS tubes or triodes. Figure 6As shown, the first switch unit 32 includes a first MOS tube M1, and the second switch unit 33 includes a second MOS tube M2. The gate of the first MOS tube M1 is connected to the first output end of the trigger 311, the drain of the first MOS tube M1 is connected to the light emitting element 10, and the source of the first MOS tube M1 is connected to the first driving unit 34; the gate of the second MOS tube M2 is connected to the second output end of the trigger 311, the drain of the second MOS tube M2 is connected to the light emitting element 10, and the source of the second MOS tube M2 is connected to the second driving unit 35. Of course, in other embodiments, a first switch unit 32 with the same function can also be selected, which is not limited in the present application.

[0057] Please also read Figure 7 As another embodiment, the switch control unit 31 includes a signal processor 312, the input end of the signal processor 312 is connected to the control module 20, the first output end of the signal processor 312 is connected to the first end of the first switch tube 321, and the second output end of the signal processor 312 is connected to the first end of the second switch tube 331. In this embodiment, the signal processor 312 outputs a first switch control signal according to the input pulse width modulation signal to control the first switch tube 321 to be continuously turned on, so that the light-emitting element 10 is continuously lit; at the same time, according to the output pulse width modulation signal, the second switch control signal is output to control the light-emitting element 10 and the second driving unit 35 to be turned on and off alternately, and the second driving unit 35 provides the second current for the light-emitting element 10. In this embodiment, the target current I of the light-emitting element 10 is I1+I2*D, where D is the duty cycle of the pulse width modulation signal, I1 is the first current provided by the first driving unit 34, and I2 is the second current provided by the second driving unit 35.

[0058] As another embodiment, the first driving unit 34 includes a controllable current source, and the second driving unit 35 includes a constant current source of a gear difference. For example, the gear of the controllable current source is 16 gears, and the target current of the light-emitting element 10 is 10.5 mA. At this time, the gear of the controllable current source is the 10th gear, and the first current corresponding to the first current is 10 mA. The gear difference provided by the constant current source of the gear difference is 1 mA, and the duty cycle is 50%, that is, the target current I=10 mA+1 mA*50%.

[0059] See also Figure 8 The embodiment of the present application further provides a driving method, which is applied to the above-mentioned driving circuit, and the driving method includes:

[0060] 100. Obtain an input signal, and output a control signal according to the input signal;

[0061] 200. Drive the light-emitting element to light up continuously according to the control signal.

[0062] In this embodiment, a control signal is output according to an input signal, a circuit path is controlled to be formed between the first power supply terminal and the second power supply terminal, and a driving current is provided for the circuit path to ensure that the light-emitting element is in a continuously lit state. Compared with the original PWM dimming process, the first level signal of the PWM signal controls the light-emitting element to light up, and the second level signal of the PWM signal controls the light-emitting element to turn off, in this application, the light-emitting element is in a continuously lit state, thereby alleviating the flicker problem of the light-emitting element in the PWM dimming method.

[0063] In some embodiments, the control signal includes a first control signal, a second control signal, and a pulse width modulation signal; wherein step 200 specifically includes: controlling the first switch unit and the second switch unit to be alternately turned on according to the pulse width modulation signal; controlling the first drive unit to provide a first current to the light-emitting element according to the first control signal, and controlling the second drive unit to provide a second current to the light-emitting element according to the second control signal. In this embodiment, the first switch unit and the second switch unit are alternately turned on according to the alternating first level signal and the second level signal, which can ensure that the light-emitting element can obtain the corresponding current to light up, thereby alleviating the flicker problem existing in PWM dimming.

[0064] In other embodiments, step 200 specifically includes: controlling the first switch unit to be continuously turned on according to the pulse width modulation signal, and the second switch unit to be alternately turned on and off; controlling the first drive unit to provide the first current to the light-emitting element according to the first control signal, and controlling the second drive unit to provide the second current to the light-emitting element according to the second control signal. In this embodiment, one of the drive units can be kept connected to the light-emitting element to ensure that one of the drive units provides current to the light-emitting element, and the other drive unit provides the corresponding current to the light-emitting element according to the pulse width modulation signal. The light-emitting element remains lit during the entire display control process, which can also alleviate the flicker problem existing in PWM dimming.

[0065] An embodiment of the present application further provides a display device, which includes the above-mentioned driving circuit. Since the driving circuit is described in detail above, it will not be repeated here.

[0066] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0067] The driving circuit provided in the embodiments of the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A driving circuit, characterized in that: The driving circuit comprises: Light emitting element; A control module, the control module is used to output a control signal according to an input signal; A driving module, the driving module is connected to the control module and the light-emitting element respectively, and the driving module is used to drive the light-emitting element to continuously light up according to the control signal; The driving module includes a switch control unit, a first switch unit, a second switch unit, a first driving unit and a second driving unit; The switch control unit is connected to the control module, the control end of the first switch unit and the control end of the second switch unit respectively, the first connection end of the first switch unit is connected to the light emitting element, the second connection end of the first switch unit is connected to the first driving unit, the first connection end of the second switch unit is connected to the light emitting element, and the second connection end of the second switch unit is connected to the second driving unit; The switch control unit includes a trigger, an input end of the trigger is connected to the control module, a first output end of the trigger is connected to the control end of the first switch unit, and a second output end of the trigger is connected to the control end of the second switch unit; the control signal includes a first control signal, a second control signal and a pulse width modulation signal; the switch control unit is used to control the first switch unit and the second switch unit to be alternately turned on according to the pulse width modulation signal; the first drive unit is used to provide a first current to the light-emitting element according to the first control signal; the second drive unit is used to provide a second current to the light-emitting element according to the second control signal; the first drive unit includes a first controllable current source, the second drive unit includes a second controllable current source, and the control module sets the current gears of the first controllable current source and the second controllable current source according to the target current of the light-emitting element; Or, the switch control unit includes a signal processor, the input end of the signal processor is connected to the control module, the first output end of the signal processor is connected to the control end of the first switch unit, and the second output end of the signal processor is connected to the control end of the second switch unit; the control signal includes a first control signal, a second control signal and a pulse width modulation signal; the switch control unit is used to control the first switch unit to be continuously turned on according to the pulse width modulation signal, and the second switch unit to be alternately turned on and off; the first drive unit is used to provide a first current to the light-emitting element according to the first control signal; the second drive unit is used to provide a second current to the light-emitting element according to the second control signal; the first drive unit includes a controllable current source, and the second drive unit includes a constant current source of the gear difference.

2. The driving circuit according to claim 1, characterized in that: The first switch unit includes a first switch tube, a first end of the first switch tube is connected to the first control end of the switch control unit, a second end of the first switch tube is connected to the output end of the light-emitting element, and a third end of the first switch tube is connected to the first driving unit.

3. The driving circuit according to claim 2, characterized in that: The second switch unit includes a second switch tube, a first end of the second switch tube is connected to the second control end of the switch control unit, a second end of the second switch tube is connected to the output end of the light-emitting element, and a third end of the second switch tube is connected to the second driving unit.

4. The driving circuit according to claim 1, characterized in that: The first current and the second current each include a plurality of different current values.

5. A driving method, characterized in that: The driving method is applied to the driving circuit according to any one of claims 1 to 4, and the driving method comprises: Acquire an input signal, and output a control signal according to the input signal; Driving the light-emitting element to light up continuously according to the control signal; The control signal includes a first control signal, a second control signal and a pulse width modulation signal, and driving the light-emitting element to continuously light up according to the control signal includes: Controlling the first switch unit and the second switch unit to be alternately turned on according to the pulse width modulation signal; Controlling the first driving unit to provide a first current to the light emitting element according to the first control signal, and controlling the second driving unit to provide a second current to the light emitting element according to the second control signal; Or the control signal includes a first control signal, a second control signal and a pulse width modulation signal, and driving the light-emitting element to continuously light up according to the control signal includes: Controlling the first switch unit to be continuously turned on and the second switch unit to be alternately turned on and off according to the pulse width modulation signal; The first driving unit is controlled according to the first control signal to provide a first current to the light emitting element, and the second driving unit is controlled according to the second control signal to provide a second current to the light emitting element.

6. A display device, characterized in that: The display device comprises the driving circuit according to any one of claims 1-4.

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