CN113554985B

CN113554985B - Organic light emitting diode driving apparatus, control method and display device

Info

Publication number: CN113554985B
Application number: CN202010338073.7A
Authority: CN
Inventors: 刘俊彦; 陈英杰; 刘至哲; 韦育伦; 朱家庆
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-04-26
Filing date: 2020-04-26
Publication date: 2022-11-11
Anticipated expiration: 2040-04-26
Also published as: WO2021218500A1; CN113554985A

Abstract

The application provides an Organic Light Emitting Diode (OLED) driving device, a control method of the OLED driving device and a control device. The OLED driving device includes: the OLED driving circuit comprises a first switching tube and a second switching tube which are connected in series, wherein the first switching tube, the second switching tube and an OLED are connected in series; and in the time period when the first switch tube is in a conducting state, the second switch tube is used for carrying out multiple switching actions to control the light-emitting time of the OLED. When the second switch tube performs multiple switching actions, the first switch tube is in a conducting state, the switching times of the first switch tube are reduced, and therefore the times that the control signal of the first switch tube charges the parasitic capacitor at the control end of the first switch tube are reduced, and loss is reduced.

Description

Organic light emitting diode driving apparatus, control method and display device

Technical Field

The present application relates to the field of circuits, and in particular, to an organic light emitting diode driving apparatus, a control method, and a display device.

Background

With the development of science and technology and the gradual increase of consumption level, people have higher and higher requirements on the use experience of the display device. Organic Light Emitting Diode (OLED) display devices are widely used. The OLED driving circuit can realize the adjustment of the brightness of the OLED.

In some OLED driving circuits, two switching tubes are included in series in the current path of the OLED. The two switching tubes are controlled by the same control signal and are switched on or off simultaneously. As the frequency of the control signal increases, the power consumption generated by the OLED driving circuit increases.

Disclosure of Invention

The application provides an OLED driving device which can reduce generated power consumption.

In a first aspect, an OLED driving device is provided, which includes a first switching tube and a second switching tube connected in series, where the first switching tube, the second switching tube, and an OLED are connected in series; and in the time period when the first switch tube is in a conducting state, the second switch tube is used for carrying out multiple switching actions to control the light-emitting time of the OLED.

When the second switch tube performs multiple switching actions, the first switch tube is in a conducting state, the switching times of the first switch tube are reduced, and therefore the times that the control signal of the first switch tube charges the parasitic capacitor at the control end of the first switch tube are reduced, and loss is reduced.

With reference to the first aspect, in some possible implementations, the OLED driving device includes a third switching tube, a fourth switching tube, and a fifth switching tube; the third switching tube is connected with the first switching tube and the second switching tube in series, the third switching tube is positioned between the first switching tube and the second switching tube, and the first switching tube or the second switching tube is positioned between the third switching tube and the OLED; the first end of the fourth switching tube is connected with the first end of the third switching tube, and the second end of the fourth switching tube is connected with the control end of the third switching tube; the first end of the fifth switching tube is connected with the second end of the third switching tube, and the second end of the fifth switching tube is used for receiving data signals.

The OLED driving device can comprise a third switching tube, and the voltage of the control end of the third switching tube can control the current flowing through the OLED, so that the luminous brightness of the OLED is controlled. The OLED driving device can realize threshold voltage compensation of the third switching tube, so that afterimages are relieved.

When the third switching tube control end receives the data signal, the data signal flows through the third switching tube and is transmitted to the control end of the third switching tube. The first switching tube and the second switching tube are cut off when the third switching tube control end receives the data signal, so that the transmission of the data signal is realized.

With reference to the first aspect, in some possible implementations, in a compensation phase, the first switching tube and the second switching tube are in an off state, and the fourth switching tube and the fifth switching tube are in an on state; in a light emitting stage, the fourth switching tube and the fifth switching tube are in a cut-off state; in the light-emitting stage, the first switch tube keeps a conducting state.

In the light-emitting stage, the first switch tube keeps a conducting state, the switching times of the first switch tube are further reduced, and the power consumption is reduced.

With reference to the first aspect, in some possible implementation manners, the first switch tube is configured to be turned on or off according to a first control signal, a cycle of the first control signal is 1/N of a display cycle, the display cycle includes a light-emitting stage and a compensation stage, and N is a positive integer; in the compensation stage, the first switching tube and the second switching tube are in a cut-off state, and the fourth switching tube and the fifth switching tube are in a conducting state; in the light-emitting stage, the fourth switching tube and the fifth switching tube are in a cut-off state; and in the light-emitting stage and in the time period when the first switch tube is in a conducting state, the second switch tube is used for carrying out multiple switching actions to control the light-emitting time of the OLED.

The period of the first control signal is 1/N of the display period, so that the design difficulty of the first control signal is reduced.

When the period of the first control signal is equal to the display period, the first control signal may be a pulse signal having an equal width per period. The pulse width may also be referred to as a pulse width. The periodic pulse width of the first control signal is unchanged, and the design difficulty of the first control signal is reduced.

When the display period is equal to an integral multiple of the period of the first control signal, the first control signal may be a pulse signal with equal width of each period, or a Pulse Width Modulation (PWM) signal.

With reference to the first aspect, in some possible implementation manners, the first switch tube is configured to be turned on or off according to a first control signal, the second switch tube is configured to be turned on or off according to a second control signal, and a period of the first control signal is a positive integer multiple of a period of the second control signal.

The period of the control signal is set, so that the period of the first control signal is a positive integral multiple of the period of the second control signal, and the design difficulty of the control signal can be reduced.

With reference to the first aspect, in some possible implementation manners, the second switching tube is configured to be turned on or off according to a second control signal, and the second control signal is a PWM signal.

The second control signal is a PWM signal, and the duration of the current flowing through the OLED can be controlled by controlling the pulse width of the second control signal, so as to control the luminance of the OLED.

In a second aspect, a display device is provided, which includes an OLED and the OLED driving apparatus of the first aspect.

In a third aspect, a control method of an OLED driving device is provided, where the OLED driving device includes a first switching tube and a second switching tube connected in series, and the first switching tube, the second switching tube, and an OLED are connected in series; the method comprises the following steps: generating a plurality of control signals, wherein the plurality of control signals comprise a first control signal and a second control signal, the first control signal is used for controlling the first switch tube, and the second control signal is used for controlling the second switch tube; the plurality of control signals cause: in the light emitting stage of the OLED, the second switch tube performs switching action to control the light emitting time of the OLED in the time period when the first switch tube is in a conducting state; and sending the first control signal and the second control signal to the OLED driving device.

With reference to the third aspect, in some possible implementations, the OLED driving device includes a third switching tube, a fourth switching tube, and a fifth switching tube; the third switching tube is connected with the first switching tube and the second switching tube in series, the third switching tube is positioned between the first switching tube and the second switching tube, and the first switching tube or the second switching tube is positioned between the third switching tube and the OLED; the first end of the fourth switching tube is connected with the first end of the third switching tube, and the second end of the fourth switching tube is connected with the control end of the third switching tube; the first end of the fifth switching tube is connected with the second end of the third switching tube, and the second end of the fifth switching tube is used for receiving data signals.

With reference to the third aspect, in some possible implementations, the plurality of control signals includes a third control signal, and the third control signal is used to control the fourth switching tube and the fifth switching tube; the plurality of control signals cause: in a compensation stage, the first switching tube and the second switching tube are in a cut-off state, and the fourth switching tube and the fifth switching tube are in a conducting state; in a light emitting stage, the fourth switching tube and the fifth switching tube are in a cut-off state; in the light-emitting stage, the first switch tube keeps a conducting state.

With reference to the third aspect, in some possible implementations, the plurality of control signals includes a third control signal, and the third control signal is used to control the fourth switching tube and the fifth switching tube; the period of the first control signal is 1/N of the display period, the display period comprises a light-emitting stage and a compensation stage, and N is a positive integer; the plurality of control signals cause: in the compensation stage, the control signal is used for controlling the first switching tube and the second switching tube to be in a cut-off state, and controlling the fourth switching tube and the fifth switching tube to be in a conducting state; in the light-emitting stage, the control signal is used for controlling the fourth switching tube and the fifth switching tube to be in a cut-off state; in the light-emitting stage and in a time period when the first control signal controls the first switch tube to be in a conducting state, the second control signal is used for controlling the second switch tube to perform multiple switching actions so as to control the light-emitting time of the OLED.

With reference to the third aspect, in some possible implementations, a period of the first control signal is a positive integer multiple of a period of the second control signal.

With reference to the third aspect, in some possible implementations, the second control signal is a PWM signal.

In a fourth aspect, a control device for an OLED driving device is provided, which includes a memory and a processor; the memory is used for storing programs; the processor is configured to perform the method of the third aspect when the program is executed in the control apparatus.

In a fifth aspect, a control device of an OLED driving device is provided, which includes various functional modules for performing the method of the third aspect.

In a sixth aspect, there is provided a display device comprising the OLED of the fourth or fifth aspect, an OLED driving means, and a control means of the OLED driving means.

In a seventh aspect, a computer storage medium is provided, the computer storage medium storing program code comprising instructions for performing the steps of the method of the first or second aspect.

In an eighth aspect, a chip system is provided, the chip system comprising at least one processor, which when program instructions are executed in the at least one processor, causes the chip system to perform the method of the first or second aspect.

Optionally, as an implementation manner, the chip system may further include a memory, the memory has instructions stored therein, and the processor is configured to execute the instructions stored on the memory, and when the instructions are executed, the processor is configured to execute the method in the first aspect.

The chip system may be specifically a field programmable gate array FPGA or an application specific integrated circuit ASIC.

It should be understood that, in the present application, a method of the third aspect may specifically refer to the third aspect as well as a method in any one of various implementations of the third aspect.

Drawings

Fig. 1 is a schematic structural view of an OLED driving device.

Fig. 2 is a schematic diagram of a control signal.

Fig. 3 is a schematic structural diagram of an OLED driving device provided in an embodiment of the present application.

Fig. 4 is a schematic structural diagram of another OLED driving device provided in an embodiment of the present application.

Fig. 5 is a schematic structural diagram of another OLED driving device provided in an embodiment of the present application.

Fig. 6 is a schematic structural diagram of another OLED driving device provided in an embodiment of the present application.

Fig. 7 is a schematic diagram of a control signal provided in an embodiment of the present application.

Fig. 8 is a schematic structural diagram of another OLED driving device provided in an embodiment of the present application.

Fig. 9 is a schematic diagram of another control signal provided in the embodiment of the present application.

Fig. 10 is a schematic flowchart of a control method of an OLED driving device according to an embodiment of the present application.

Fig. 11 is a schematic structural diagram of a control device of an OLED driving device according to an embodiment of the present application.

Fig. 12 is a schematic structural diagram of another control device of an OLED driving device according to an embodiment of the present application.

Fig. 13 is a schematic structural diagram of a display device provided in an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

An Organic Light Emitting Diode (OLED), which may also be called an organic electroluminescent display, an organic light emitting semiconductor, or the like, is a current type organic light emitting device, and emits light by injection and recombination of carriers, and the light emitting intensity is proportional to the injected current. Under the action of an electric field, holes generated by an anode and electrons generated by a cathode move, are respectively injected into a hole transport layer and an electron transport layer, and migrate to a light emitting layer. When the two meet at the light emitting layer, energy excitons are generated, thereby exciting the light emitting molecules to finally generate visible light.

Fig. 1 is a schematic structural view of an OLED driving device.

The drive circuit of the OLED comprises switching tubes M1 to M7 and a capacitor C.

The on and off of the switch tube can be controlled by current or voltage. The switch tube controlled by current can be called as current control switch tube, and the switch tube controlled by voltage can be called as voltage control switch tube or voltage control switch tube. Each switch tube comprises a control end, a first end and a second end. The control signal received by the control end of the switch tube is used for controlling the switch states of the first end and the second end of the switch tube. The switch state of the switch tube comprises a conducting state and a cut-off state. The control signal of the current control switch tube is a current signal, namely the state of the switch tube is controlled by the current flowing through the control end. The control signal of the voltage-controlled switch tube is a voltage signal, namely the state of the switch tube is controlled by the voltage of the control end.

The switch tube M4 is a voltage-controlled switch tube. When the switch tube is in a conducting state, the maximum value of the current flowing through M4 can be controlled by the size of the control signal received by the control end of the switch tube.

The switching transistors M1 to M7 are all voltage-controlled switching transistors for example.

The switching tubes M6, M4, M5 are connected in series. The first end of M6 is connected to the power supply potential VDD, the second end of M6 is connected to the first end of M4, the second end of M4 is connected to the first end of M5, and the second end of M5 is connected to the anode of the OLED. The cathode of the OLED is connected to ground potential VSS. The power supply potential VDD and the ground potential VSS are used to provide a voltage difference between the anode and the cathode of the OLED.

The first end of the capacitor C is connected to the power supply potential VDD, and the second end of the capacitor C, the control end of the switch tube M4, the first end of the switch tube M3, and the first end of the switch tube M1 are connected to the node a.

The second end of the switch tube M3 is connected to the second end of the switch tube M4. The second terminal of the switching tube M1 is connected to the reference potential Vint.

The first end of the switch tube M7 is connected to the reference potential Vint, and the second end of the switch tube M7 is connected to the node B between the second end of the switch tube M4 and the anode of the OLED.

The control signals of the switch tube M2 and the switch tube M3 are N. The control signals of the switch tube M1 and the switch tube M7 are N-1. The control signals of the switching tube M5 and the switching tube M6 are EM.

The following description will be made by taking an example in which the switching tubes are turned on when the control signals of the switching tubes M1 to M7 are at low level, and turned off when the control signals are at low level. The reference potential Vint is low. The waveform diagrams of the control signals N, N-1, EM are shown in FIG. 2.

In the time period t1, reset of the drive circuit is performed. The time period t1 may also be referred to as a reset phase.

Control signal N-1 is low and control signal N and control signal EM are high. At this time, the switching tubes M1 and M7 are turned on, and the switching tubes M2, M3, M5, and M6 are turned off.

The switch tube M1 is turned on, so that the potential of the node a is equal to the reference potential Vint, and therefore, the switch tube M4 is turned on.

The voltage difference between the reference potential Vint and the ground potential VSS can cause the OLED to turn off. The switch M7 is turned on, and the switch M5 is turned off, so that the potential of the node B is lowered to the reference potential Vint, before entering the third stage.

Between the time period t1 and the time period t2, a hold phase may or may not exist. And in the time period corresponding to the holding stage, the control signals N-1, N and EM are all high level. At this time, the switching tubes M1, M7, M2, M3, M5, and M6 are all turned off, the capacitor C is short-circuited, the potential of the node a is maintained at the reference potential Vint, and M4 is turned on.

In the time period t2, the data signal Vdata is transmitted to the control terminal of the switch transistor M4. The time period t2 may also be referred to as a compensation (compensation) phase or a voltage extraction phase.

Control signal N is low, and control signal N-1 and control signal EM are high. At this time, the switching tubes M2 and M3 are turned on, and the switching tubes M1, M7, M5, and M6 are turned off.

The potential of the node B remains unchanged and remains at the reference potential Vint.

When the compensation stage is started, the switching tube M4 is switched on, and the data signal Vdata charges the node A. At the beginning of the compensation phase, the potential of the node a is the reference potential Vint. Since the switch tube M3 is turned on, the potential of the node a rises. The data signal Vdata is transmitted to the node a through the switching tubes M2, M4, M3. When the potential difference Vgs = Vth between the node a and the data signal Vdata, M4 is turned off. Where Vth is the threshold voltage of M4. The potential of the node A is Vdata-Vth.

During the time period t3, the driving circuit controls the OLED to emit light. The time period t3 may also be referred to as a light emission period.

The control signal EM may be low and the control signals N-1 and N high. At this time, the switching tubes M5 and M6 are turned on, and the switching tubes M1, M7, M2, and M3 are turned off. The voltage across the capacitor C remains unchanged, that is, the potential of node a remains Vdata-Vth unchanged.

When Vdata-Vth is larger than or equal to Vth, M4 is conducted, and the OLED emits light. The potential VB of the node B may be represented as VB = VSS + Voled. Voled is the turn-on voltage of the OLED.

When Vdata-Vth < Vth, M4 is turned off and the OLED does not emit light.

The data signal Vdata is an analog signal. Taking the example where the switch M4 is a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), when the switch M4 works in the saturation region, the current through the OLED (i.e. the current through the switch M4) Isd4 can be expressed as

Wherein mu is carrier mobility, the control end of the switching tube M4 is a grid, C _gi Is the gate capacitance per unit area of the switching tube M4, W is the gate width of the switching tube M4, L is the gate width of the switching tube M4, and k is a constant related to the process parameters such as the size and material of the switching tube M4.

Therefore, the brightness of the pixel point can be obtained by adjusting the potential of the data signal Vdata.

For OLED screens, the data signal Vdata is determined from the data. The data signal Vdata for each pixel may be the same or different depending on the information that the OLED screen needs to display.

In the OLED screen, the switching tube is usually implemented by a thin film transistor (thin film transistor). The TFT type display screen can be applied to various notebook computers, desktop computers and other equipment as display equipment, each liquid crystal pixel point on the display screen is driven by a thin film transistor integrated behind the pixel point, and therefore the TFT type display screen is also active matrix liquid crystal display equipment. The TFT display screen can display screen information with high speed, high brightness and high contrast.

Due to the characteristics of the TFT, the conductivity of the TFT may decrease as the on time of the TFT increases. Under long-time pressurization and high temperature, the threshold voltage of the TFT can shift, the difference of display brightness can be caused by different display pictures and different threshold shift amounts of the TFT at each part of the panel, and the difference is related to the image displayed before, so that the phenomenon of afterimage, namely afterimage, is often presented.

In the driving circuit shown in fig. 1, in the compensation phase, the threshold voltage Vth of the switching tube M4 is stored in the gate-source voltage Vgs between the gate (gate) and the source (source) (Vgs = Vdata), and when the light is finally emitted, vgs-Vth is converted into current, because Vgs already contains Vth, and the influence of the switching tube Vth on the current flowing through the switching tube can be reduced when the Vth is converted into current.

In order to reduce the threshold voltage Vth shift of the switching tube M4, current uniformity is achieved. By turning over the control signal EM in the light-emitting phase, the switching tubes M6 and M5 are in the off state for a part of the time in the light-emitting phase, that is, no current flows through the switching tubes M6, M5 and M4 in the part of the time in the light-emitting phase, the switching tubes M6, M5 and M4 can be turned off for a short time to recover the self state, and the recovered switching tubes M6, M5 and M4 can reduce the image retention phenomenon.

In order to adjust the brightness of the entire screen in different environments, the duty ratio of the control signal EM may be adjusted by Pulse Width Modulation (PWM) to control the light emission time of the OLED, thereby adjusting the brightness of the OLED. The duty cycle of the control signal EM of the driving circuit of each pixel in the OLED screen is equal.

If the switching frequency of the control signal EM is low (e.g. using a PWM signal less than or equal to 240 Hertz (Hz)) during the light emitting period, it may enable human eyes to perceive that the light emission of the pixels in the OLED screen is discontinuous, i.e. a phenomenon causing a screen flash occurs. And (4) flashing, namely, flickering or flickering of the screen picture. Increasing the switching frequency of the control signal EM results in an increase of the power consumption. The frequency of the control signal EM increases and the switching frequency of the switching tubes M5 and M6 increases. The switching tube performs a switching operation, and a parasitic gate capacitor of the switching tube needs to be charged and discharged.

The switching transistors M5 and M6 are p-channel MOSFETs (PMOS) for example. The PMOS substrate is connected to high. When the control signal EM is at a low level, the switching transistors M5 and M6 are in a conducting state, that is, the gate voltages of the switching transistors M5 and M6 are at a low level. When the control signal EM controls the switching tubes M5 and M6 to turn off, the control signal EM is inverted from a low level to a high level, and the gate voltages of the switching tubes M5 and M6 are increased from a low level voltage to a high level voltage. The gate voltage rises, i.e. the gate capacitance of the switching tubes M5 and M6 charges. Similarly, when the control signal EM is inverted from high level to low level to control the switching tubes M5 and M6 to be turned on, the gate voltages of the switching tubes M5 and M6 are reduced from high level to low level, and the gate capacitances of the switching tubes M5 and M6 are discharged. Therefore, in the process that the control signal EM controls the switching of the switching tubes M5 and M6, the gate capacitances of the switching tubes M5 and M6 are charged and discharged, so that power consumption is generated. As the frequency of the control signal EM increases, the gate capacitance charging and discharging speed of the switching tubes M5 and M6 increases, and the power consumption increases.

A display period may be understood as a time interval between displaying two consecutive frames of images. That is, the display period may be a display time of one frame image. Each display period includes a compensation phase such that the data signal Vdata is transmitted to the switching transistor M4.

Table 1 reflects the relationship between the frequency of the control signal EM and the power consumption caused by the control signal EM during one display period. Wherein, the EM power consumption represents the power consumption generated by the control signal EM and has unit of milliwatt-Watt (mW).

TABLE 1

EM frequency (Hz)	Number of EM pulses in display period	EM power consumption (mW)
			240	4	4.37
480	8	10.19
			960	16	17.95
1920	32	36.57

In order to solve the above problem, embodiments of the present application provide an OLED driving device.

The OLED driving apparatus provided in the embodiment of the present application may be applied to an electronic device including an OLED display device, such as a television, a mobile phone, a tablet computer, a wearable device, an in-vehicle device, an Augmented Reality (AR)/Virtual Reality (VR) device, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, a Personal Digital Assistant (PDA), and the like, and the embodiment of the present application does not limit the specific type of the electronic device.

The electronic device implements a display function through a Graphics Processing Unit (GPU), a display screen, and an application processor. The GPU is a microprocessor for image processing and is connected with a display screen and an application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. The processor 110 may include one or more GPUs that execute program instructions to generate or alter display information.

The display device may also be referred to as a display screen for displaying images, video, etc. The display screen includes a display panel. The display panel may be a Liquid Crystal Display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode (active-matrix organic light-emitting diode, AMOLED), a flexible light-emitting diode (FLED), a mini-diode (MiniLED), a Micro-LED, a Micro-OLED, a quantum dot light-emitting diode (QLED), or the like. In some embodiments, the electronic device may include 1 or N display screens, N being a positive integer greater than 1.

Fig. 3 is an OLED driving device according to an embodiment of the present disclosure.

The OLED driving device 300 includes a first switching tube and a second switching tube. The first switch tube, the second switch tube and the OLED are connected in series.

It should be understood that the OLED driving device 300 may be located between the anode of the OLED and the power supply VDD, that is, the first switching tube and the second switching tube may be both located between the OLED and the power supply VDD. The OLED driving device 300 may also be located between the cathode of the OLED and the ground VSS, that is, the first switching tube and the second switching tube may both be located between the OLED and the ground VSS. Alternatively, the OLED may be located between the first switching tube and the second switching tube.

Fig. 3 illustrates an example in which the first switch tube and the second switch tube are both located between the OLED and the power supply VDD. The first switch tube may be any one of the switch tubes M5 and M6, and the second switch tube is the other one of the switch tubes M5 and M6.

The control signal can be transmitted to the control end of the switch tube to control the on or off of the switch tube. The control signal of the first switch tube is a first control signal, and the first switch tube is used for switching on or switching off according to the first control signal. The control signal of the second switch tube is a second control signal, and the second switch tube is switched on or switched off according to the second control signal. The control signal of the switching tube M6 is EM1, and the control signal of the switching tube M5 is EM2.

And in the time period when the first switch tube is in a conducting state, the second switch tube is used for carrying out switching action to control the light-emitting time of the OLED.

That is, the first control signal controls the first switch tube to be in the on state time period, and the second control signal controls the second switch tube to perform multiple switching actions.

The switch tube in the OLED driving device 300 may be a MOSFET or other type of transistor, and may be all or part of an n-channel MOSFET (n-channel MOSFET) or a PMOS, for example. In fig. 3, the first switching transistor and the second switching transistor are PMOS as an example.

When the first switch tube is switched on, the second switch tube can perform switching action or keep a conducting or cut-off state. The switching tube performs a switching operation, i.e., a switching between an on state and an off state. One switching operation may be an on operation, i.e., a switching from an off state to an on state, or an off operation, i.e., a switching from an on state to an on state.

If the first switch tube and the second switch tube are simultaneously switched on, the second switch tube performs multiple switching actions within the time period when the first switch tube is in a conducting state, so that current can flow through the OLED for multiple times.

If the second switch tube is kept to be cut off when the first switch tube is switched on, the second switch tube performs more than 3 times of switching actions in the time period when the first switch tube is in a conducting state, so that current can flow through the OLED for multiple times.

In the time period from the turning-on of the first switch tube to the turning-off of the first switch tube, the parasitic capacitance at the control end of the first switch tube is charged and discharged for one time, and the parasitic capacitance at the control end of the second switch tube is charged and discharged for multiple times. Compared with the situation that the first switch tube and the second switch tube are controlled by the same control signal, and are simultaneously turned on and turned off, the charging and discharging times of the parasitic capacitor at the control end of the first switch tube are reduced.

The first control signal and the second control signal may be periodic signals. Different switching frequencies can be set for control signals of the first switching tube and the second switching tube on the OLED current loop, and when the first switching tube is in a conducting state, the second switching tube performs multiple switching actions, so that the number of times of charging and discharging parasitic capacitance of the control end of the first switching tube is reduced, and loss is reduced.

The OLED driving device 300 provided in the embodiments of the present application can be used to implement threshold voltage compensation or other functions.

As shown in fig. 4, the OLED driving device 300 may further include a switching tube M4 and a switching tube M3. One of the switch tube M5 and the switch tube M6 is a first switch tube, and the other is a second switch tube.

The switch tube M4 is connected with the first switch tube and the second switch tube in series, the switch tube M4 is located between the first switch tube and the second switch tube, and the first switch tube or the second switch tube is located between the switch tube M4 and the OLED.

As shown in fig. 4, the switching tube M5 is located between the switching tube M4 and the OLED. The switch tube M5 is a first switch tube or a second switch tube.

The switching tube M3 is located between the first end of the switching tube M4 and the control end of the switching tube M4. As shown in fig. 4, the first end of the switch tube M4 may be the end of the switch tube M4 connected to the switch tube M5. Alternatively, as shown in fig. 5, the first end of the switching tube M4 may be the end of the switching tube M4 connected to the switching tube M6.

In a compensation stage when the control end of the switching tube M4 receives the data signal Vdata, the switching tube M6 and the switching tube M5 are in a cut-off state, the switching tube M3 is in a conducting state, and the data signal Vdata is transmitted to the control end of the switching tube M4 through the switching tube M4 and the switching tube M3. The compensation phase is a time period outside the light emitting phase.

When the data signal Vdata is transmitted to the control end of the switching tube M4 through the switching tube M4, that is, the data signal Vdata is transmitted to the control end of the switching tube M4, the current between the two points, i.e., the signal line for transmitting the data signal Vdata and the control end of the switching tube M4, is transmitted through the switching tube M4.

That is to say, in the compensation phase, the switching tube M3 is in the conduction phase, that is, the first end of the switching tube M4 is connected to the control end of the switching tube M4, and the data signal Vdata is transmitted to the first end of the switching tube M4, that is, to the control end of the switching tube M4 through the second end of the switching tube M4.

At the beginning of the compensation phase, the switching tube M4 is turned on.

In the compensation stage, the first switch tube and the second switch tube are in a cut-off state, so that the switch tube M4 is disconnected from the power supply VDD and the ground VSS, and the data signal Vdata is transmitted to the control end of the switch tube M4 through the switch tube M4. After the compensation phase, the voltage Vgs = Vdada-Vth of the control end of M4, where Vth is the threshold voltage of the switching tube M4.

That is, the first switch tube M6 and the second switch tube M5 are used to disconnect the switch tube M4 from the power VDD and the ground VSS in the compensation phase, and the data signal Vdata is transmitted to the control end of the switch tube M4 through the switch tube M4 to form compensation for the threshold voltage Vth of the switch tube M4.

The switch transistor M5 may be used as a first switch transistor, and the switch transistor M6 may be used as a second switch transistor. The OLED is supplied with current by a power supply VDD and a data signal Vdata.

In order to avoid the voltage value of each node on the loop of the light emitting stage OLED from influencing the data signal Vdata, the OLED driving device 300 may further include a switch M2. One of the switch tube M5 and the switch tube M6 is a first switch tube, and the other switch tube is a second switch tube.

The first end of the switch tube M2 is used for receiving the data signal Vdata. That is, the first end of the switch M2 is connected to the transmission line of the data signal Vdata. The second end of the switch tube M2 is connected to the second end of the switch tube M4. As shown in fig. 4, the second end of the switch tube M4 is connected to the switch tube M6. As shown in fig. 5, the second end of the switch tube M4 is connected to the switch tube M5.

In the compensation phase, the switch tube M2 is in a conducting state, so that the data signal Vdata is transmitted to the second end of the switch tube M4.

In the light emitting phase, the switch tube M2 is in a cut-off state to disconnect the data line for transmitting the data signal Vdata from the second end of the switch tube M4.

Therefore, in the light emitting phase, the control terminal of the switch M4 is disconnected from the switch M5, and the second terminal of the switch M4 is disconnected from the transmission line of the data signal Vdata, so that the switch M6, the switch M5, and the switch M4 control the brightness of the OLED.

The switch M4 controls the current magnitude through the voltage of the control terminal, thereby controlling the current magnitude when the current flows through the OLED. The control signal EM1 controls the conduction time of the switching tube M6, and the control signal EM2 controls the conduction time of the switching tube M5, so as to control the time of the current flowing through the OLED, and thus control the light emitting time of the OLED.

After the compensation phase, the light emission phase may be entered through or through the hold phase. In the holding stage, the switching tubes M5, M6, M2, and M3 are all in the off state, and the voltage of the control end of the switching tube M4 remains unchanged.

When or before entering the light-emitting stage, the first control signal may control the first switch tube to be turned on. In the light emitting phase, the first control signal may or may not include a turn-off signal for controlling the first switch tube to be in a turn-off state. That is, in the light emitting stage, the first switching tube may be always in the on state, or the first switching tube may perform a switching operation.

In the light-emitting stage, when the first switch tube is in the conducting state, the second switch tube can perform multiple switching actions to control the light-emitting time of the OLED.

When the first switch tube is in a cut-off state, the second switch tube can perform a switching action.

Alternatively, in the light emitting stage, when the first switch tube is in the off state, the second control signal may be kept in the on state or the off state. The second switch tube is in a conducting state or a cut-off state, so that the times of charging and discharging parasitic capacitance at the control end of the second switch tube can be reduced, and the loss is further reduced.

In addition, when the first switch tube is in the cut-off state, the second switch tube is controlled to be in the cut-off state, so that when one switch tube of the first switch tube and the second switch tube which should be in the cut-off state is turned over by mistake and enters the conducting state, the other switch tube is in the cut-off state, thereby avoiding the light emission of the OLED and improving the reliability of the OLED driving device 300.

To facilitate the design of the first control signal, the first control signal may be a periodic signal. For example, the period T1 of the first control signal may be 1/N of a display period including the light emitting period and the compensation period, N being a positive integer.

The OLED driving device provided by the embodiment of the application can be applied to display equipment. When the display device displays a picture, the display period may be understood as a time interval between displaying two consecutive frames of images. That is, the display period may be a display time of one frame image.

To facilitate the design of the second control signal, the second control signal may be a periodic signal. The display period may be a positive integer multiple of the period T2 of the second control signal. Further, the period of the first control signal may be a positive integer multiple of the period of the second control signal.

The first control signal and/or the second control signal may be a PWM signal.

PWM is an effective technique for controlling an analog circuit by using the digital output of a processor, and adjusts the average voltage or average current of a switching tube by adjusting the on-time of the switching tube. The conduction time of the switch tube is controlled through the width of the PWM signal, and the light emitting time of the OLED can be controlled, so that the light emitting brightness of the OLED is adjusted.

A plurality of OLED driving devices may be included in the display apparatus. The control signals of the plurality of OLED driving devices may be the same. In some cases, the brightness of the screen as a whole is adjusted according to ambient brightness and/or user settings. The pulse width of the first control signal and/or the second control signal can be controlled, so that the light emitting brightness of a plurality of OLEDs in the display device can be uniformly adjusted.

The second control signal may employ a periodic signal during the light emitting period. The state of the first switch tube can not be considered in the overturning of the second control signal, and the design difficulty of the second control signal is reduced. The period of the second control signal is less than the time of the light emitting phase. Typically, the time of the light emission phase is equal to a positive integer multiple of the period of the second control signal. Equal may also be understood as being about equal.

In the light emitting phase, the first control signal may include a turn-on signal that the controlled first switch tube is in a turn-on state and a turn-off signal that the controlled first switch tube is in a turn-off state, see fig. 9. That is to say, in the light-emitting phase, the first control signal may be used to control the first switch tube to be turned over, where the first switch tube is in an on state for a part of the time period, and is in an off state for a part of the time period.

When the display periods are equal, the first control signal may be a periodic signal to meet the requirements of the display periods. The period T1 of the first control signal may be 1/N of the display period.

When the period of the first control signal is equal to the display period, the pulse width of the first control signal may be equal in each period.

When the period T1 of the first control signal may be 1/N of the display period, and N is greater than or equal to 2, the first control signal may be a pulse signal with a constant pulse width, or may be a PWM signal.

When the first control signal is a pulse signal with a constant pulse width, the second pulse signal may be a PWM signal, and the light emitting time of the OLED may be adjusted by adjusting the pulse width of the second pulse signal.

When the first control signal is a PWM signal, the second pulse signal may be a pulse signal having a constant pulse width, or may be a PWM signal. By adjusting the pulse width of the first control signal, the light emitting time of the OLED can be adjusted.

Preferably, the first control signal and the second control signal are both PWM signals, so as to increase flexibility of adjustment manner.

Alternatively, the first control signal may control the first switch tube to maintain a conducting state in the light emitting period, see fig. 7. That is, during the light-emitting period, the first switch tube may be in a conducting state all the time.

In the light-emitting stage, the first switch tube is kept in a conducting state, so that the charging and discharging times of a parasitic capacitor at the control end of the first switch tube can be further reduced, and the power consumption is reduced.

The control signals EM1 and EM2 may be PWM signals.

During the light emitting phase, the voltage at the control terminal of the switch M4 needs to be stable. Therefore, a capacitor can be provided at the control terminal of the switching tube M4.

The second terminal of the capacitor C is connected to the control terminal of the switch tube M4. The first terminal of the capacitor C may be connected to the power supply VDD as shown in fig. 6. The first terminal of the capacitor C may also be connected to the anode of the OLED as shown in fig. 8. Alternatively, the first end of the capacitor C may be connected to other positions, and the embodiment of the present application is not limited in particular.

In the compensation phase, the capacitor C needs to be charged or discharged, and the data signal Vdata is transmitted to the control terminal of the M4 and is held by the capacitor C. The charging and discharging of the capacitor C takes time. Therefore, the time length of the compensation phase can be longer than the time for the second switch tube to perform the switching action to realize one-time conduction or off.

In some cases, the previous data signal Vdata may cause the switch transistor M4 to be in the off state, and therefore, in order to enable the current data signal Vdata to be transmitted to the control terminal of the switch transistor M4, before the compensation phase, the voltage of the control terminal of the switch transistor M4 may be adjusted, so that the switch transistor M4 is in the on state at the beginning of the compensation phase.

In addition, before the compensation phase, the voltage of the control terminal of the switching tube M4 is adjusted, so that the switching tube M4 can pass a larger current at the beginning of the compensation phase, and the data signal Vdata can be transmitted to the control terminal of the switching tube M4 faster.

The adjustment that can be performed on the control terminal voltage of the switching tube M4 before the compensation phase can be referred to as resetting the control terminal of the switching tube M4. The time period for adjusting the voltage at the control terminal of the switching tube M4 may be referred to as a reset phase. Reference may be made in particular to the description of fig. 6 to 8.

Fig. 6 is a schematic structural diagram of an OLED driving device provided in an embodiment of the present application. The switching transistors M1 to M7 are all PMOS transistors for example.

Compared with the OLED driving device shown in fig. 1, the switching tube M5 and the switching tube M6 are no longer controlled by the same control signal, but controlled by different control signals. The switching tube M6 is controlled by the control signal EM1, and the switching tube M5 is controlled by the control signal EM2.

The switching tubes M6, M4 and M5 are connected in series. The first end of M6 is connected to the power supply potential VDD, the second end of M6 is connected to the second end of M4, the first end of M4 is connected to the first end of M5, and the second end of M5 is connected to the anode of the OLED. The cathode of the OLED is connected to ground VSS. The power supply potential VDD and the ground potential VSS are used to provide a voltage difference between the anode and the cathode of the OLED.

The first end of the switch tube M3 is connected to the control end of the switch tube M4, and the second end of the switch tube M3 is connected to the first end of the switch tube M4.

The first end of the switching tube M2 is used for receiving the data signal Vdata, and the first end of the switching tube M2 is connected to the second end of the switching tube M4.

The first end of the capacitor C is connected to the power supply potential VDD, and the second end of the capacitor C, the control end of the switch tube M4, and the first end of the switch tube M3 are connected to the node a. In the light emitting phase, the capacitor C is used to maintain the voltage of the control terminal of the switching tube M4.

In order to make the switch tube M4 in a conducting state before the compensation phase, the OLED driving device may include a switch tube M1. The first terminal of the switching tube M1 is connected to the node a, and the second terminal of the switching tube M1 is connected to the reference potential Vint.

In the reset phase before the compensation phase, the control terminal of the switching transistor M4 may be connected to the reference potential Vint, so that the switching transistor M4 is in the conducting state before the compensation phase.

Before the compensation phase, a reset phase may be set. In the reset phase, the switch tube M1 is in a conducting state. So that the reference potential Vint is transmitted to the control terminal of the switch tube M4. The reference potential Vint can control the switch tube M4 to be in a conducting state.

The OLED driving device may further include a switching tube M7. The first end of the switch tube M1 is connected to the node B between the second end of the switch tube M4 and the OLED, and the second end of the switch tube M7 is connected to the reference potential Vint. The reference potential Vint may cause the OLED to be turned off. In the light-emitting phase, the switch tube M7 is in the off state, and in the reset phase and/or the compensation phase, the switch tube M7 is in the on state.

When the switch tube M2 and the switch tube M3 are of the same type, the control signals of the switch tube M2 and the switch tube M3 may be the same or different. When the switch tube M2 and the switch tube M3 are both NMOS or PMOS, the switch tube M2 and the switch tube M3 may be controlled by the same control signal N.

When the type of the switch tube M1 or the switch tube M7 is used, the control signals of the switch tube M1 and the switch tube M7 may be the same or different. When the switch tube M1 and the switch tube M7 are both NMOS or PMOS, the switch tube M1 and the switch tube M7 may be controlled by the same control signal N-1.

Fig. 7 illustrates an example in which the switching transistors M1 to M7 are all PMOS transistors. The waveform diagrams of the control signals N, N-1, EM2 are shown in FIG. 7.

The control signal N-1 is at a low level and the control signals N, EM1, EM2 are at a high level. At this time, the switching tubes M1 and M7 are turned on, and the switching tubes M2, M3, M5, and M6 are turned off.

The voltage difference between the reference potential Vint and the ground potential VSS can cause the OLED to turn off. The switch tube M7 is turned on, the switch tube M5 is turned off, and the potential of the node B is lowered to the reference potential Vint, so that a large current can flow through the switch tube M4 when the switch tube M enters the light-emitting stage.

Between the time period t1 and the time period t2, a hold phase may or may not exist. And in the time period corresponding to the holding stage, the control signals N-1, N, EM1 and EM2 are all high level. At this time, the switching tubes M1, M7, M2, M3, M5, and M6 are all turned off, the capacitor C is short-circuited, the potential of the node a is kept at the reference potential Vint, and M4 is turned on.

The control signal N is low, and the control signals N-1, EM2 are high. At this time, the switching tubes M2 and M3 are turned on, and the switching tubes M1, M7, M5, and M6 are turned off.

When the compensation stage is started, the switching tube M4 is turned on, and the data signal Vdata is transmitted to the node a. At the beginning of the compensation phase, the potential of the node a is the reference potential Vint. Since the switch tube M3 is turned on, the potential of the node a rises. The data signal Vdata is transmitted to the node a through the switching tubes M2, M4, M3. When the potential difference between the node A and the data signal Vdata is reduced to Vth, M4 is turned off. Where Vth is the threshold voltage of M4. The potential of the node A is Vdata-Vth.

The control signals N-1 and N are high level, and the switching tubes M2, M3, M8 and M9 are cut off. When the control signal EM1 and the control signal EM2 are both at a high level, that is, the switching tubes M5 and M6 are both in a conducting state, current flows through the OLED, and the OLED emits light. The control end voltage of the switch tube M4 is Vdata-Vth, and the magnitude of the current flowing through the switch tube M4, namely the OLED, is controlled.

One of the switching tube M5 and the switching tube M6 is a first switching tube, and the other switching tube is a second switching tube. In the light-emitting stage, the second switch tube is used for performing switching action to control the light-emitting time of the OLED in the time period when the first switch tube is in the conducting state.

The first control signal may be a periodic signal to reduce the difficulty of designing the first control signal. The first control signal may be a periodic signal having a fixed width, or may be a PWM signal.

The display period comprises a reset phase, a compensation phase and a light-emitting phase. The display period may be equal to a positive integer multiple of the period T1 of the first control signal. As illustrated in fig. 9, the display period may be equal to the period T1 of the first control signal. It should be understood that equality may also be about equal.

The second control signal may be PWM, and the length of the light emitting time of the OLED may be adjusted by adjusting the width of the pulse signal, so as to control the light emitting brightness of the OLED.

The period T1 of the first control signal is greater than the period T2 of the second control signal, so that the charging and discharging frequency of the parasitic capacitor of the second switching tube is reduced, and the power consumption of the system is reduced.

For design convenience, the period T1 of the first control signal may be a positive integer multiple of the period T2 of the second control signal.

Fig. 8 is a schematic structural diagram of an OLED driving device according to an embodiment of the present application. In the OLED driving device 800, the switching transistors M1 to M7 are all NMOS transistors as an example. When the control end of the NMOS tube receives a high level signal, the NMOS tube is in a conducting state. When the control end of the NMOS tube receives a low level signal, the NMOS tube is in a cut-off state.

The switching tubes M6, M4, M5 are connected in series. The first end of the switch tube M6 is connected to the power supply potential VDD, the second end of the switch tube M6 is connected to the second end of the switch tube M4, the first end of the switch tube M4 is connected to the first end of the switch tube M5, and the second end of the switch tube M5 is connected to the anode of the OLED. The cathode of the OLED is connected to ground VSS. The power supply potential VDD and the ground potential VSS are used to provide a voltage difference between the anode and the cathode of the OLED.

The first end of the switch tube M2 is used for receiving the data signal Vdata, that is, the first end of the switch tube M2 is connected to the transmission line of the data signal Vdata. The first end of the switch tube M2 is connected to the second end of the switch tube M4.

The second end of the capacitor C, the control end of the switch tube M4, and the first end of the switch tube M3 are connected to the node a. The first end of the capacitor C, the switching tube M5 and the anode of the OLED are connected to the node B. In the light emitting period, the capacitor C is used to maintain the voltage at the control terminal of the switch transistor M4.

In order to make the switch M4 in a conducting state before the compensation phase, the OLED driving device may include a switch M8. The first terminal of the switch M8 is connected to the power supply potential VDD, and the second terminal of the switch M8 is connected to the node a.

In the reset phase before the compensation phase, the control terminal of the switching transistor M4 may be connected to the power supply potential VDD, so that the switching transistor M4 is in a conducting state before the compensation phase.

Before the compensation phase, a reset phase may be set. In the reset phase, the switch tube M8 is in a conducting state. So that the power supply potential VDD is transmitted to the control terminal of the switch transistor M4. The power supply potential VDD can control the switch transistor M4 to be in a conducting state.

The OLED driving device may further include a switching tube M9. The first end of the switching tube M9 is connected to the node B between the second end of the switching tube M4 and the anode of the OLED, and the second end of the switching tube M9 is connected to the reference potential Vint. The reference potential Vint may cause the OLED to be turned off. The switching tube M9 is in an off state during the light emitting period and in an on state during the reset period and/or the compensation period.

The control ends of the switch tube M2, the switch tube M3 and the switch tube M9 may be configured to receive the control signal P. The control terminal of the switch transistor M8 may be configured to receive the control signal P-1.

The waveforms of the control signals P, P-1, EM2 are shown in FIG. 9.

In a time period t1, i.e., a reset phase, the control signal P-1 is at a high level, and the control signals P, EM1, EM2 are at a low level. At this time, the switching tube M8 is turned on, and the switching tubes M2, M3, M5, M6, and M9 are turned off.

The switch M8 is turned on, so that the potential of the node a is equal to the power supply potential VDD, and therefore, the switch M4 is turned on.

Between the time period t1 and the time period t2, there may or may not be a hold phase. And in the time period corresponding to the holding stage, the control signals P-1, P, EM1 and EM2 are all low level. At this time, the switching tubes M2, M3, M5, M6, M8, and M9 are all turned off, the two ends of the capacitor C are equivalent to open circuits, the potential of the node a is maintained at the power supply potential VDD, and the switching tube M4 is turned on.

In the time period t2, i.e. the compensation phase, the data signal Vdata is transmitted to the control terminal of the switching tube M4.

The control signal P is high level, and the control signals P-1, EM2 are high level and low level. At this time, the switching tubes M2 and M3 are turned on, and the switching tubes M5 and M6 are turned off.

The switch tube M9 is turned on, and the potential of the node B is the reference potential Vint.

When the compensation stage is started, the switching tube M4 is switched on, and the data signal Vdata is transmitted to the node A. At the beginning of the compensation phase, the potential of the node A is the reference potential VDD. Since the switch tube M3 is turned on, the potential of the node a rises. The data signal Vdata is transmitted to the node a through the switching tubes M2, M4, M3. When the potential difference Vgs = Vth between the node a and the data signal Vdata, the switching tube M4 is turned off. Where Vth is the threshold voltage of M4. When the switch tube M4 is turned off, the potential of the node A is Vdata-Vth.

In the time period t3, i.e. the light emitting period, the OLED driving device drives the OLED to emit light.

The control signals EM1, EM2 are high, and the control signals P-1, P are low. The switching tubes M5 and M6 are switched on, the switching tubes M2, M3, M8 and M9 are switched off, the control end voltage of the switching tube M4 is Vdata-Vth, and the current flowing through the switching tube M4, namely the current flowing through the OLED, is controlled.

One of the switching tube M5 and the switching tube M6 is a first switching tube, and the other switching tube is a second switching tube. In the light-emitting stage, the second switch tube is used for performing switching action to control the light-emitting time of the OLED within the time period that the first switch tube is in a conducting state.

The display period comprises a reset phase, a compensation phase and a light-emitting phase. The display period may be equal to a positive integer multiple of the period T1 of the first control signal. As illustrated in fig. 9, the display period may be equal to the period T1 of the first control signal. It should be understood that equality may also be approximately equal.

The period T1 of the first control signal is greater than the period T2 of the second control signal, so that the charging and discharging frequency of the parasitic capacitor of the second switch tube is reduced, and the power consumption of the system is reduced.

Through the OLED driving device provided by the embodiment of the application, the power consumption can be reduced.

Table 2 reflects the relationship between the frequencies of the control signals EM1 and EM2 and the power consumption caused by the control signals. The switching tube M5 and the switching tube M6 both use MOSFETs with a width-to-length ratio of W/L (unit: micrometer (mum)). Ref denotes a reference value.

TABLE 2

According to the power calculation formula, each time the parasitic capacitance of the MOSFET control end is charged, the power consumption is

P＝f·Cgs·V ²

Wherein f represents the frequency of the control signal at the control terminal of the MOSFET, cgs represents the parasitic capacitance at the control terminal of the MOSFET, and V represents the voltage of the control signal at the control terminal of the MOSFET.

When the switching tube M5 and the switching tube M6 are controlled by the same control signal EM with a frequency of 960Hz, the power consumption generated by the control signal EM is P1=2 × 960 × Cgs · V ² 。

When one of the switch tube M5 and the switch tube M6 is controlled by the first control signal with the frequency of 960Hz and the other switch tube is controlled by the second control signal with the frequency of 240Hz, the power consumption generated by the first control signal and the second control signal is P2=960 xCgs · V ² +240×Cgs·V ² The power consumption decreases by 37.5%.

The OLED driving device comprises a first switch tube and a second switch tube which are connected in series, and the first switch tube, the second switch tube and the OLED are connected in series.

In step S1001, a plurality of control signals are generated.

The plurality of control signals includes a first control signal and a second control signal.

The first control signal is used for controlling the first switch tube, and the second control signal is used for controlling the second switch tube.

The plurality of control signals enable the first control signal to control the first switch tube to be in a time period of a conducting state, and the second control signal to control the second switch tube to carry out multiple switching actions so as to control the light emitting time of the OLED.

In step S1002, a control signal is transmitted to the OLED driving device.

Optionally, the OLED driving device includes a third switching tube, a fourth switching tube, and a fifth switching tube.

The third switching tube is connected with the first switching tube and the second switching tube in series, the third switching tube is located between the first switching tube and the second switching tube, and the first switching tube or the second switching tube is located between the third switching tube and the OLED.

The first end of the fourth switching tube is connected with the first end of the third switching tube, and the second end of the fourth switching tube is connected with the control end of the third switching tube.

The first end of the fifth switching tube is connected with the second end of the third switching tube, and the second end of the fifth switching tube is used for receiving data signals.

Optionally, the plurality of control signals includes a third control signal, and the third control signal is used for controlling the fourth switching tube and the fifth switching tube.

The plurality of control signals cause: in a compensation stage, the first switching tube and the second switching tube are in a cut-off state, and the fourth switching tube and the fifth switching tube are in a conducting state; in a light emitting stage, the fourth switching tube and the fifth switching tube are in a cut-off state; in the light-emitting stage, the first switch tube keeps a conducting state.

The period of the first control signal is 1/N of the display period, the display period comprises a light-emitting stage and a compensation stage, and N is a positive integer.

In the compensation stage, the control signal is used for controlling the first switching tube and the second switching tube to be in a cut-off state, and controlling the fourth switching tube and the fifth switching tube to be in a conducting state.

In the light-emitting stage, the control signal is used for controlling the fourth switching tube and the fifth switching tube to be in a cut-off state.

In the light-emitting stage and in a time period when the first control signal controls the first switch tube to be in a conducting state, the second control signal is used for controlling the second switch tube to perform multiple switching actions so as to control the light-emitting time of the OLED.

Optionally, a period of the first control signal is a positive integer multiple of a period of the second control signal.

Optionally, the second control signal is a PWM signal.

The control device 1100 comprises a generation module 1101 and a transmission module 1102.

The generating module 1101 is configured to generate a control signal.

The sending module 1102 is configured to send a control signal to the OLED driving apparatus.

The control signals include a first control signal and a second control signal.

The control signal enables the first control signal to control the first switch tube to be in a time period of a conducting state, and the second control signal controls the second switch tube to carry out multiple switching actions so as to control the light emitting time of the OLED.

The third switch tube is connected with the first switch tube and the second switch tube in series, the third switch tube is located between the first switch tube and the second switch tube, and the first switch tube or the second switch tube is located between the third switch tube and the OLED.

And the first end of the fourth switching tube is connected with the first end of the third switching tube, and the second end of the fourth switching tube is connected with the control end of the third switching tube.

The plurality of control signals cause: in a compensation stage, the first switching tube and the second switching tube are in a cut-off state, and the fourth switching tube and the fifth switching tube are in a conducting state; in a light-emitting stage, the fourth switching tube and the fifth switching tube are in a cut-off state; in the light-emitting stage, the first switch tube keeps a conducting state.

In the period of time that the first switch tube is controlled to be in a conducting state by the first control signal in the light-emitting stage, the second control signal is used for controlling the second switch tube to perform multiple switching actions so as to control the light-emitting time of the OLED.

Optionally, the second control signal is a PWM signal.

Fig. 12 is a schematic structural diagram of a control device of an OLED driving device according to an embodiment of the present application.

The control device 1200 includes a processor 1201 and a communication interface 1202.

The communication interface 1202 is used for controlling the apparatus 1200 to perform information interaction with the OLED driving apparatus, and when the program instructions are executed in the processor 1201, the control apparatus 1200 is enabled to perform the method described above.

The processor 1201 is configured to generate a plurality of control signals, the plurality of control signals including a first control signal and a second control signal, the first control signal being used to control the first switch transistor, the second control signal being used to control the second switch transistor,

The communication interface 1202 is configured to send the control signal to the OLED driving apparatus.

Optionally, the plurality of control signals includes a third control signal, and the third control signal is used to control the fourth switching tube and the fifth switching tube.

Optionally, the second control signal is a PWM signal. Fig. 13 is a display device provided in an embodiment of the present application. The display apparatus includes a control device of an OLED driving device and a plurality of OLED cells (cells). Each OLED unit comprises an OLED driving device and an OLED driven by the OLED driving device. The control device of the OLED driving device may be a gate driver on array (GOA) device.

The plurality of OLEDs form an array and the GOAs are used to generate control signals for each row of OLEDs in the display device corresponding to a display screen.

In this array, each OLED cell inputs the same reference signal Vint. The Vdata input to each OLED cell can be the same or different.

The power consumption resulting from the control signal may also be referred to as panel power.

Embodiments of the present application further provide a display device, which includes the OLED and the OLED driving apparatus described above.

An embodiment of the present application further provides a display device, which includes the OLED, the OLED driving device, and the control device of the OLED driving device described above.

Embodiments of the present application further provide a computer program storage medium, which is characterized by having program instructions, when the program instructions are directly or indirectly executed, the method in the foregoing is implemented.

An embodiment of the present application further provides a chip system, where the chip system includes at least one processor, and when a program instruction is executed in the at least one processor, the method in the foregoing is implemented.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the technical solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one type of logical functional division, and other divisions may be realized in practice, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The OLED driving device is characterized by comprising a first switching tube and a second switching tube which are connected in series, wherein the first switching tube, the second switching tube and an OLED are connected in series;

and in the time period when the first switch tube is in a conducting state, the second switch tube is used for carrying out multiple switching actions to control the light-emitting time of the OLED.

2. The OLED driving device according to claim 1, comprising a third switching tube, a fourth switching tube, a fifth switching tube;

the third switching tube is connected with the first switching tube and the second switching tube in series, the third switching tube is positioned between the first switching tube and the second switching tube, and the first switching tube or the second switching tube is positioned between the third switching tube and the OLED;

the first end of the fourth switching tube is connected with the first end of the third switching tube, and the second end of the fourth switching tube is connected with the control end of the third switching tube;

3. The OLED driving device according to claim 2,

in a compensation stage, the first switching tube and the second switching tube are in a cut-off state, and the fourth switching tube and the fifth switching tube are in a conducting state;

in a light emitting stage, the fourth switching tube and the fifth switching tube are in a cut-off state;

in the light-emitting stage, the first switch tube keeps a conducting state.

4. The OLED driving device according to claim 2, wherein the first switch transistor is configured to be turned on or off according to a first control signal, a period of the first control signal is 1/N of a display period, the display period includes a light-emitting period and a compensation period, N is a positive integer;

in the compensation stage, the first switching tube and the second switching tube are in a cut-off state, and the fourth switching tube and the fifth switching tube are in a conducting state;

in the light-emitting stage, the fourth switching tube and the fifth switching tube are in a cut-off state;

and in the light-emitting stage and in the time period when the first switch tube is in a conducting state, the second switch tube is used for carrying out multiple switching actions to control the light-emitting time of the OLED.

5. The OLED driving device according to any one of claims 2 to 4, wherein the first switch tube is configured to be turned on or off according to a first control signal, the second switch tube is configured to be turned on or off according to a second control signal, and a period of the first control signal is a positive integer multiple of a period of the second control signal.

6. The OLED driving device according to any one of claims 1-4, wherein the second switch is turned on or off according to a second control signal, and the second control signal is a PWM signal.

7. A display device comprising the organic light emitting diode OLED and the OLED driving device as claimed in any one of claims 1 to 6.

8. The control method of the OLED driving device is characterized in that the OLED driving device comprises a first switching tube and a second switching tube which are connected in series, and the first switching tube, the second switching tube and the OLED are connected in series;

the method comprises the following steps:

generating a plurality of control signals, wherein the plurality of control signals comprise a first control signal and a second control signal, the first control signal is used for controlling the first switch tube, the second control signal is used for controlling the second switch tube,

the plurality of control signals cause: in the light-emitting stage of the OLED, in the time period when the first switch tube is in a conducting state, the second switch tube performs switching action to control the light-emitting time of the OLED;

and sending the plurality of control signals to the OLED driving device.

9. The method according to claim 8, wherein the OLED driving device comprises a third switch tube, a fourth switch tube, a fifth switch tube;

10. The method of claim 9, wherein the plurality of control signals comprises a third control signal for controlling the fourth switching tube and the fifth switching tube;

the plurality of control signals cause:

in a light-emitting stage, the fourth switching tube and the fifth switching tube are in a cut-off state;

in the light-emitting stage, the first switch tube keeps a conducting state.

11. The method of claim 9, wherein the plurality of control signals comprises a third control signal for controlling the fourth switching tube and the fifth switching tube;

the period of the first control signal is 1/N of the display period, the display period comprises a light-emitting stage and a compensation stage, and N is a positive integer;

the plurality of control signals cause:

in the compensation stage, the first switching tube and the second switching tube are in a cut-off state, and the fourth switching tube and the fifth switching tube are controlled to be in a conducting state;

and in the light-emitting stage and in the time period when the first switch tube is in a conducting state, the second switch tube carries out multiple switching actions to control the light-emitting time of the OLED.

12. The method of any of claims 9-11, the period of the first control signal being a positive integer multiple of the period of the second control signal.

13. The method according to any of claims 8-11, wherein the second control signal is a PWM signal.

14. The control device of the OLED driving device is characterized by comprising a memory and a processor;

the memory is used for storing programs;

the processor is configured to perform the method of any one of claims 8-13 when the program is executed in the control device.

15. A display device comprising the OLED of claim 14, an OLED driving means, and a control means of the OLED driving means.

16. A control device for an organic light emitting diode OLED driving device, comprising functional blocks for performing the method of any one of claims 8 to 13.

17. A computer-readable storage medium, characterized in that the computer-readable medium stores program code for execution by a device, the program code comprising instructions for performing the method of any of claims 8-13.

18. A chip, characterized in that the chip comprises a processor and a data interface, the processor reading instructions stored on a memory through the data interface to perform the method according to any one of claims 8-13.