Multipath independent adjustable OLED constant current driver and OLED constant current driving method

Abstract

The invention relates to the technical field of power electronics, in particular to a multipath independent adjustable OLED constant-current driver and an OLED constant-current driving method, and the driver comprises an interaction assembly which is used for receiving target OLED current and target irradiation time; the OLED constant-current driving assembly is connected with the OLED matrix module, and is used for determining a DAC voltage based on the target OLED current and the target irradiation time, controlling the OLED constant-current driving assembly to output the target OLED current based on the DAC voltage, collecting an actual output current of the OLED constant-current driving assembly, correcting the DAC voltage according to the target OLED current and the actual output current, and outputting the corrected target OLED current. And the OLED constant current driving assembly outputs the target output current. Therefore, the problems of small output current, low current stability, high manufacturing cost and the like in the prior art are solved, the stability of the output current and the size of the output current are improved, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of drive control, and in particular to a multi-channel independently adjustable OLED constant current driver and an OLED constant current driving method. Background Art

[0002] Organic light-emitting diodes (OLEDs) have great application potential in the fields of lighting and display. As a new type of display technology, it has many advantages such as self-luminescence, high contrast, wide viewing angle, and fast response speed. It has been widely used in small-sized panels and has also shown great potential in the field of large-sized displays. The OLED driver plays a vital role in the OLED display system. It is responsible for controlling the light emission of the OLED panel and directly affects the quality and performance of the OLED display. OLED is a light-emitting diode composed of organic materials, and its structure usually includes an anode, an organic light-emitting layer, and a cathode. In a passive OLED device, the light emission of each pixel is driven by the current provided by an external circuit. The driving characteristic of the passive OLED device is current drive, that is, the brightness of the pixel is proportional to the driving current. Therefore, in order to achieve a uniform display effect, it is necessary to ensure that the driving current of each pixel is uniform.

[0003] In the related art, there are generally the following ways to drive OLED with constant current: (1) Mainly through a simple constant current source, that is, using a stable current source to provide a constant current for the OLED. It is usually composed of a reference voltage source, a resistor and a transistor. The reference voltage source generates a stable voltage, which is converted into a current through the resistor, and then the transistor controls the on and off and size of the current, thereby realizing constant current driving of the OLED. (2) Current mirror solution: Based on the current mirror principle of the transistor, a reference current source and multiple current mirror transistors are used to provide the same constant current for multiple OLEDs. The reference current source generates a precise current, and the current mirror transistor copies the current to each OLED driving branch, thereby realizing constant current driving of multiple pixels (3) Pulse width modulation (PWM) constant current driver solution: The average current of the OLED is controlled by adjusting the width of the pulse signal. In a fixed period, when the pulse signal is high, the constant current source provides current to the OLED, and when the pulse signal is low, the current is zero. By changing the ratio of pulse width to period, i.e. duty cycle, the average current of OLED pixels can be changed, thereby achieving different brightness displays. (4) Polycrystalline silicon thin film transistor (TFT) constant current driver solution: constant current drive is achieved by utilizing the characteristics of polycrystalline silicon TFT. Polycrystalline silicon TFT has high carrier mobility and good current control capability. By properly designing the size and layout of TFT, precise constant current drive of OLED can be achieved.

[0004] However, although solution (1) has a simple circuit structure, low cost and is easy to implement, its disadvantages are that the current accuracy is relatively low, it is greatly affected by the power supply voltage and process deviation, and the output current is small. The advantage of solution (2) is that the current accuracy is high. The disadvantage is that a large chip area is required to implement multiple current mirror transistors, and the matching requirements of the transistors are high, otherwise it will cause current errors and small output current. The advantage of solution (3) is that it can achieve wide-range brightness adjustment without changing the current size of the constant current source, and has high efficiency and low power consumption. The disadvantage is that a fast switching circuit is required to realize the control of the pulse signal, and the speed and stability requirements of the circuit are high, which will cause the OLED to flicker. The advantage of solution (4) is that it can be integrated with the OLED display panel on the same substrate, reducing the number of external driver chips, reducing costs and power consumption. The disadvantage is that the process of polysilicon TFT is relatively complex, and there are problems such as threshold voltage drift. Special compensation technology is required to ensure the stability and consistency of the current. The production cost is high and needs to be solved urgently. Summary of the invention

[0005] The present invention provides a multi-channel independently adjustable OLED constant current driver and a driving method thereof, so as to solve the problems of small output current, low current stability, high manufacturing cost, etc., improve the stability and size of the output current, and reduce the manufacturing cost.

[0006] The first aspect of the present invention provides a multi-channel independently adjustable OLED constant current driver, including: an interactive component for receiving a target OLED current and a target illumination time; an OLED constant current driving component, the OLED constant current driving component being connected to an OLED matrix module, for determining a DAC voltage based on the target OLED current and the target illumination time, and controlling the OLED constant current driving component to output the target OLED current based on the DAC voltage, and collecting the actual output current of the OLED constant current driving component, and correcting the DAC voltage according to the target OLED current and the actual output current, so that the OLED constant current driving component outputs the target output current.

[0007] Further, in some embodiments, the OLED constant current driving component includes: a digital-to-analog conversion unit, an analog-to-digital conversion unit, first to fourth resistors, a control unit, a diode and a MOS tube, wherein the digital-to-analog conversion unit is used to convert the target OLED current into the DAC voltage; one end of the first resistor is connected to the bias voltage access node; one end of the second resistor is connected to the other end of the first resistor; one end of the third resistor is connected to the output end of the digital-to-analog conversion unit, and the other end of the third resistor is connected to the connection node between the first resistor and the second resistor; the gate of the MOS tube is connected to the connection node between the first resistor and the second resistor, the source of the MOS tube is connected to the power access node, and the drain of the MOS tube is connected to one end of the fourth resistor; the other end of the fourth resistor is connected to the ground node; one end of the analog-to-digital conversion unit is connected to the drain of the MOS tube, for collecting the actual output current of the OLED constant current driving component; a control unit, the control unit is respectively connected to the other end of the analog-to-digital conversion unit and the input end of the digital-to-analog conversion unit, for correcting the DAC voltage according to the target OLED current and the actual output current.

[0008] Furthermore, in some embodiments, the OLED constant current driving component further includes: a light emitting diode disposed between the power access node and the source of the MOS tube.

[0009] Furthermore, in some embodiments, the multi-channel independently adjustable OLED constant current driver further includes: a power supply unit, wherein the power supply unit is connected to the control unit and is used to supply power to the control unit.

[0010] Furthermore, in some embodiments, the multi-channel independently adjustable OLED constant current driver further includes: a debugging interface provided in the control component, for debugging according to a debugging instruction.

[0011] Further, in some embodiments, the interactive component includes: an input unit for inputting the target OLED current and the target irradiation time; a display unit for displaying the target OLED current, and / or the target irradiation time, and / or the actual output current.

[0012] Furthermore, in some embodiments, the multi-channel independently adjustable OLED constant current driver further includes: the display unit is a liquid crystal display screen.

[0013] According to the multi-channel independently adjustable OLED constant current driver provided by the embodiment of the present invention, real-time constant current control of multiple high-power OLED devices can be achieved, and each channel is independently adjustable. The current of each OLED device can be conveniently set to change the luminous intensity. At the same time, the luminous time of each OLED device can be set. Any current setting of 5 to 500mA is achieved, and the output current is controlled in steps of 1mA. A larger constant current output can be achieved by adjusting the circuit parameters. The problems of small output current, low current stability, and high production cost are solved, the stability of the output current and the size of the output current are improved, and the production cost is reduced.

[0014] The second aspect of the present invention provides an OLED constant current driving method, comprising the following steps: receiving a target OLED current and a target illumination time; determining a DAC voltage based on the target OLED current and the target illumination time, and controlling the OLED constant current driving component to output the target OLED current based on the DAC voltage.

[0015] Furthermore, in some embodiments, the OLED constant current driving method further includes: collecting an actual output current of the OLED constant current driving component; and correcting the DAC voltage according to the target OLED current and the actual output current so that the OLED constant current driving component outputs the target output current.

[0016] Furthermore, in some embodiments, the OLED constant current driving method further includes: displaying the target OLED current, and / or the target irradiation time, and / or the actual output current.

[0017] According to the OLED constant current driving method provided by the embodiment of the present invention, real-time constant current control of multiple high-power OLED devices can be achieved, and each channel is independently adjustable. The current of each OLED device can be conveniently set to change the luminous intensity. At the same time, the luminous time of each OLED device can be set. Any current setting of 5 to 500mA is achieved, and the output current is controlled in steps of 1mA. A larger constant current output can be achieved by adjusting the circuit parameters. The problems of small output current, low current stability, and high production cost are solved, the stability of the output current and the size of the output current are improved, and the production cost is reduced.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A schematic block diagram of a multi-channel independently adjustable OLED constant current driver according to an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the structure of a multi-channel independently adjustable OLED constant current driver system according to a specific embodiment of the present invention;

[0022] Figure 3 A circuit diagram of a multi-channel independently adjustable OLED constant current driver according to a specific embodiment of the present invention;

[0023] Figure 4 A flow chart of an OLED constant current driving method according to a specific embodiment of the present invention;

[0024] Figure 5 A flow chart of an OLED constant current driving method according to another specific embodiment of the present invention;

[0025] Figure 6 The figure is a flow chart of an OLED constant current driving method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0027] The following describes the multi-channel independent adjustable OLED constant current driver and its driving method of the embodiment of the present invention with reference to the accompanying drawings. In view of the relatively low current accuracy mentioned in the above background technology, the large impact of power supply voltage and process deviation, and the small output current, the present invention provides a multi-channel independent adjustable OLED constant current driver to achieve constant current control and current program control settings for high-power OLED devices, and facilitate the setting of OLED light-emitting body current, change of luminous intensity and irradiation time. It can achieve arbitrary current settings of 5 to 500mA, and control the output current in steps of 1mA. By adjusting the circuit parameters, a larger constant current output can be achieved. In this way, the problems of small output current, low current stability, and high production cost are solved.

[0028] Specifically, Figure 1 A block diagram of a multi-channel independently adjustable OLED constant current driver provided by an embodiment of the present invention.

[0029] like Figure 1 As shown, the multi-channel independently adjustable OLED constant current driver 10 includes: an interactive component 100 and an OLED constant current driving component 200 .

[0030] Among them, the interactive component 100 is used to receive the target OLED current and the target irradiation time; the OLED constant current driving component 200 is connected to the OLED matrix module, and is used to determine the DAC voltage based on the target OLED current and the target irradiation time, and control the OLED constant current driving component to output the target OLED current based on the DAC voltage, and collect the actual output current of the OLED constant current driving component, and correct the DAC voltage according to the target OLED current and the actual output current, so that the OLED constant current driving component outputs the target output current.

[0031] In some embodiments, the interactive component 100 includes: an input unit and a display unit. The input unit is used to input the target OLED current and the target irradiation time; the display unit is used to display the target OLED current, and / or the target irradiation time, and / or the actual output current.

[0032] Optionally, in some embodiments, the display unit is a liquid crystal display screen.

[0033] It should be noted that in order to study the stress response of cells, the effects of photosynthesis, the mechanism of light damage and other aspects, the test experiment will control variables such as light intensity, wavelength, and irradiation time, and use a series of detection methods to observe the physiological changes of cells. It is necessary to control the light intensity and irradiation time.

[0034] Furthermore, in some embodiments, Figure 3As shown, the OLED constant current driving component 200 includes: a digital-to-analog conversion unit DAC, an analog-to-digital conversion unit ADC, first to fourth resistors, a control unit MCU, a diode LED1 and a MOS tube, wherein the digital-to-analog conversion unit DAC is used to convert the target OLED current into a DAC voltage; one end of the first resistor R1 is connected to the bias voltage access node; one end of the second resistor R2 is connected to the other end of the first resistor R1; one end of the third resistor R3 is connected to the output end of the digital-to-analog conversion unit DAC, and the other end of the third resistor R3 is connected to the connection node between the first resistor R1 and the second resistor R2; the gate of the MOS tube is connected to the connection node between the first resistor R1 and the second resistor R2, the source of the MOS tube is connected to the power access node, and the drain of the MOS tube is connected to one end of the fourth resistor Rs; the other end of the fourth resistor Rs is connected to the ground node; one end of the analog-to-digital conversion unit ADC is connected to the drain of the MOS tube, and is used to collect the actual output current of the OLED constant current driving component 200; the control unit MCU is respectively connected to the other end of the analog-to-digital conversion unit ADC and the input end of the digital-to-analog conversion unit DAC, and is used to correct the DAC voltage according to the target OLED current and the actual output current. It should be noted that DAC and ADC are one of the cores of digital control constant current drivers. Their resolution and accuracy directly affect the accuracy of current control. Higher resolution can provide more precise current regulation. 12-bit DAC and ADC can provide 2 12 = 4096 levels, which can more accurately control the current flowing through the OLED, and the DAC and ADC have a higher conversion speed and can quickly feedback the current size.

[0035] Furthermore, in some embodiments, the OLED constant current driving component 200 further includes: a light emitting diode disposed between the power access node and the source of the MOS tube.

[0036] The light-emitting diode between the power access node and the source of the MOS tube is used to visualize the working state of the MOS tube. If the light-emitting diode between the power access node and the source of the MOS tube is lit, it means that the MOS tube is in a normal working state. If the light-emitting diode between the power access node and the source of the MOS tube is not lit, it means that the MOS tube is not in a normal working state.

[0037] Specifically, combined Figures 1 to 3 ,in, Figure 2 This is a schematic diagram of the structure of a multi-channel independently adjustable OLED constant current driver system according to a specific embodiment of the present invention. Figure 3The circuit diagram of a multi-channel independent adjustable OLED constant current driver provided according to a specific embodiment of the present invention is shown in the figure. The MCU (i.e., control unit) communicates with the DAC (i.e., digital-to-analog conversion unit) through a data bus, sets the OLED current through the LCD screen interface of the interactive component 100, and the DAC converts the set current into a voltage signal. The OLED driving circuit controls the output current through the voltage of the DAC, thereby determining the luminous intensity of the OLED matrix module. The ADC (i.e., analog-to-digital conversion unit) matrix circuit reads the voltage on the sampling resistor of the OLED driving matrix in a time-sharing manner and transmits it back to the MCU through the data bus. The MCU continuously adjusts the DAC voltage through algorithm analysis and comparison to keep the current passing through the OLED constant. Through this closed-loop control method, the OLED luminous intensity can be conveniently set, and the OLED is controlled to emit light according to the set current parameters. Due to the existence of the feedback mechanism, the current flowing through the OLED is guaranteed to be constant, the luminous intensity is stable and controllable, and the service life of the device is extended.

[0038] Among them, through the design of programmable interactive interface, any current of 5 to 500mA can be set, with a step of 1mA. And the appropriate digital control algorithm is used to achieve precise control of the constant current source, and a larger constant current output can be achieved by changing the circuit parameters.

[0039] Furthermore, the embodiment of the present invention can utilize the influence of the gate voltage Vgs (gate-source voltage) of the MOS tube on the resistance value of Rds (i.e., the internal resistance of the MOS tube) and use a digital signal to control the output current of the constant current source. The present invention converts the digital signal into a voltage signal through a high-precision DAC (i.e., digital-to-analog converter) to control the Vgs gate voltage so that the OLED driver outputs current. The sampling resistor voltage is collected through the ADC (i.e., analog-to-digital converter), the output current of the OLED driver is dynamically adjusted, and the DAC output voltage is set to adjust the MOS tube Vgs to achieve a constant current flowing through the OLED through continuous comparison by the program-controlled algorithm.

[0040] Specifically, there is a nonlinear relationship between the gate voltage and drain current of the MOS tube. When the gate voltage increases, the drain current will increase within a certain range. However, when the gate voltage reaches a certain level, the increase in drain current will gradually slow down until saturation. In the linear resistance region of the MOS tube, the relationship between the gate voltage and the drain current can be expressed by the formula IDS = k(V GS -V TH )express.

[0041] Among them, the multi-channel controllable OLED constant current driver works in the linear resistance area, and R1, R2, and R3 form a voltage divider circuit to meet the superposition principle:

[0042]

[0043] IDS=k(VGS -V TH ) (2)

[0044] Where IDS is the drain current, V GS is the gate-source voltage, V TH is the threshold voltage, k is a coefficient related to the characteristics of the MOS tube, Rs is the sampling resistor, Rs = 0.5Ω, and the resistance values ​​of R1, R2, R3, and V are determined in formula (1). bias Voltage, so that the MOS tube works in the linear resistance region. In formula (2), V GS (gate voltage) and IDS (drain current) have a linear relationship. Increasing V in the control circuit DAC (DAC output voltage) IDS increases, and vice versa decreases. The DAC output voltage accuracy determines the OLED constant current driver accuracy. By using this method to programmatically change the DAC output voltage, the OLED constant current driver output current can be changed.

[0045] Furthermore, in some embodiments, the multi-channel independently adjustable OLED constant current driver 10 further includes: a power supply unit, wherein the power supply unit is connected to the control unit and is used to supply power to the control unit. The power supply unit can use a constant current power supply to facilitate the use of digital signals to control the output current of the constant current source.

[0046] Furthermore, in some embodiments, the multi-channel independently adjustable OLED constant current driver 10 further includes: a debugging interface, wherein the debugging interface is provided at the control component interface and is used for debugging according to debugging instructions.

[0047] Among them, debugging instructions can be issued by users according to actual needs to implement relevant debugging.

[0048] Specifically, the embodiments of the present invention can utilize some debugging devices to be connected to the control component via a debugging interface, thereby facilitating the user to perform relevant debugging actions, and the specific debugging content can be determined according to actual conditions.

[0049] In order to enable those skilled in the art to better understand the multi-channel independently adjustable OLED constant current driver according to the embodiment of the present invention, it will be explained below in conjunction with specific embodiments.

[0050] Figure 4 This is a flow chart of an OLED constant current driving method provided according to a specific embodiment of the present invention, comprising the following steps:

[0051] In step S401 , the user sets the current and irradiation time of each OLED.

[0052] The current of the OLED is set through the liquid crystal display interface of the interactive component 100, and the OLED driving circuit controls the output current through the voltage of the DAC, thereby determining the luminous intensity of the OLED matrix module and determining the luminous time.

[0053] In step S402, a multi-channel matrix DAC is used to control the gate voltage of the MOS tube.

[0054] In step S403, the OLED is driven by a multi-channel matrix circuit.

[0055] In step S404, the OLED current is collected in real time through a multi-channel matrix ADC.

[0056] In step S405, the DAC output is adjusted in a timely manner according to the collected current.

[0057] Furthermore, the embodiment of the present invention can also realize OLED constant current driving control by the user controlling the switch of the OLED according to the user's use needs.

[0058] Figure 5 The figure is a flow chart of an OLED constant current driving method according to another embodiment of the present invention.

[0059] The embodiment includes the following steps:

[0060] In step S501, the user interface is initialized.

[0061] In step S502, the user sets the current and illumination time of each OLED.

[0062] In step S503, it is determined whether the user turns on the OLED, if the OLED is turned on, step S504 is executed, otherwise, step S506 is executed to turn it off.

[0063] In step S504, a matrix DAC is set to control the gate voltage of the MOS tube.

[0064] In step S505, the current of each OLED channel is collected in real time.

[0065] In step S506 , the OLED is turned off.

[0066] Furthermore, in order to enable those skilled in the art to better understand the effects of the embodiments of the present invention, an OLED current accuracy test table will be used for illustration below.

[0067] Table 1 is a table showing the OLED current accuracy test of channel 1 according to a specific embodiment of the present invention. Table 2 is a table showing the OLED current accuracy test of channel 2 according to a specific embodiment of the present invention.

[0068] Table 1

[0069]

[0070]

[0071] Table 2

[0072]

[0073] Therefore, the embodiment of the present invention has designed and developed a 6-channel prototype, which can achieve high-precision control of the current flowing through the OLED. Test data shows that the current error is less than ±5%. In addition, the current of the programmable interactive interface is easy to set, and the timer can be set to accurately control the OLED switching time.

[0074] According to the multi-channel independently adjustable OLED constant current driver provided by the embodiment of the present invention, real-time constant current control of multiple high-power OLED devices can be achieved, and each channel is independently adjustable. The current of each OLED device can be conveniently set to change the luminous intensity. At the same time, the luminous time of each OLED device can be set. Any current setting of 5 to 500mA is achieved, and the output current is controlled in steps of 1mA. A larger constant current output can be achieved by adjusting the circuit parameters. The problems of small output current, low current stability, and high production cost are solved, the stability of the output current and the size of the output current are improved, and the production cost is reduced.

[0075] Next, the OLED constant current driving method according to the embodiment of the present invention is described with reference to the accompanying drawings.

[0076] Figure 6 The figure is a flow chart of an OLED constant current driving method according to an embodiment of the present invention.

[0077] like Figure 6 As shown, the OLED constant current driving method includes the following steps:

[0078] In step S601, a target OLED current and a target irradiation time are received;

[0079] In step S602, a DAC voltage is determined based on a target OLED current and a target illumination time, and an OLED constant current driving component is controlled to output the target OLED current based on the DAC voltage.

[0080] Furthermore, in some embodiments, the OLED constant current driving method further includes: collecting the actual output current of the OLED constant current driving component; and correcting the DAC voltage according to the target OLED current and the actual output current so that the OLED constant current driving component outputs the target output current.

[0081] Furthermore, in some embodiments, the OLED constant current driving method further includes: displaying a target OLED current, and / or a target irradiation time, and / or an actual output current.

[0082] It should be noted that the above explanation of the embodiment of the multi-channel independently adjustable OLED constant current driver is also applicable to the OLED constant current driving method of this embodiment, and will not be repeated here.

[0083] According to the OLED constant current driving method provided by the embodiment of the present invention, real-time constant current control of multiple high-power OLED devices can be achieved, and each channel is independently adjustable. The current of each OLED device can be conveniently set to change the luminous intensity. At the same time, the luminous time of each OLED device can be set. Any current setting of 5 to 500mA is achieved, and the output current is controlled in steps of 1mA. A larger constant current output can be achieved by adjusting the circuit parameters. As a result, the problems of small output current, low current stability, and high production cost are solved, the stability of the output current and the size of the output current are improved, and the production cost is reduced.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0085] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0086] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0087] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0088] A person skilled in the art may understand that all or part of the steps in the above-mentioned embodiment method may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

Claims

1. A multi-channel independently adjustable OLED constant current driver, characterized in that: include: An interaction component for receiving a target OLED current and a target irradiation time; An OLED constant current driving component is connected to the OLED matrix module, and is used to determine a DAC voltage based on the target OLED current and the target illumination time, and control the OLED constant current driving component to output the target OLED current based on the DAC voltage, and collect the actual output current of the OLED constant current driving component, and correct the DAC voltage according to the target OLED current and the actual output current, so that the OLED constant current driving component outputs the target output current.

2. The multi-channel independently adjustable OLED constant current driver according to claim 1, characterized in that: The OLED constant current driving component includes: a digital-to-analog conversion unit, an analog-to-digital conversion unit, first to fourth resistors, a control unit, a diode and a MOS tube, wherein: The digital-to-analog conversion unit is used to convert the target OLED current into the DAC voltage; One end of the first resistor is connected to the bias voltage access node; One end of the second resistor is connected to the other end of the first resistor; One end of the third resistor is connected to the output end of the digital-to-analog conversion unit, and the other end of the third resistor is connected to the connection node between the first resistor and the second resistor; The gate of the MOS tube is connected to the connection node between the first resistor and the second resistor, the source of the MOS tube is connected to the power access node, and the drain of the MOS tube is connected to one end of the fourth resistor; The other end of the fourth resistor is connected to the ground node; One end of the analog-to-digital conversion unit is connected to the drain of the MOS tube, and is used to collect the actual output current of the OLED constant current driving component; A control unit is connected to the other end of the analog-to-digital conversion unit and the input end of the digital-to-analog conversion unit respectively, and is used to correct the DAC voltage according to the target OLED current and the actual output current.

3. The multi-channel independently adjustable OLED constant current driver according to claim 2, characterized in that: The OLED constant current driving component further includes: A light emitting diode is arranged between the power supply access node and the source of the MOS tube.

4. The multi-channel independently adjustable OLED constant current driver according to claim 2, characterized in that: Also includes: A power supply unit is connected to the control unit and is used to supply power to the control unit.

5. The multi-channel independently adjustable OLED constant current driver according to claim 2, characterized in that: Also includes: The debugging interface provided in the control component is used for debugging according to the debugging instruction.

6. The multi-channel independently adjustable OLED constant current driver according to claim 1, characterized in that: The interactive component includes: An input unit, used for inputting the target OLED current and the target irradiation time; A display unit is used to display the target OLED current, and / or the target irradiation time, and / or the actual output current.

7. The multi-channel independently adjustable OLED constant current driver according to claim 6, characterized in that: The display unit is a liquid crystal display screen.

8. An OLED constant current driving method, characterized in that: The method comprises the following steps: receiving a target OLED current and a target irradiation time; A DAC voltage is determined based on the target OLED current and the target illumination time, and the OLED constant current driving component is controlled to output the target OLED current based on the DAC voltage.

9. The method according to claim 8, characterized in that Also includes: Collecting the actual output current of the OLED constant current driving component; The DAC voltage is corrected according to the target OLED current and the actual output current, so that the OLED constant current driving component outputs the target output current.

10. The method according to claim 9, characterized in that Also includes: The target OLED current, and / or the target irradiation time, and / or the actual output current are displayed.

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