Display device and control method thereof

Abstract

The application discloses a display device and a control method thereof. The method comprises the following steps: in a current display control period, determining whether a current detected lamp bead is in a working state according to a control signal of a first switch unit corresponding to a light-emitting diode in the current detected lamp bead; if the current detected lamp bead is in the working state, controlling a third switch unit to be disconnected and a second switch unit to be closed; controlling a sampling module to collect a PN junction voltage of a current detected light-emitting diode in the current detected lamp bead; when a timing duration reaches a preset duration, determining a current temperature of the current detected light-emitting diode according to the PN junction voltage, and determining a compensation value according to the current temperature; compensating the control signal of the first switch unit corresponding to the current detected light-emitting diode according to the compensation value, and controlling the first switch unit corresponding to the current detected light-emitting diode according to the compensated control signal in a working stage. The technical scheme of the application improves the display performance of the display device.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a display device and its control method. Background Technology

[0002] Light-emitting diodes (LEDs) are commonly used light-emitting devices, found in automotive interior lighting. In recent years, with the diversification and intelligent development of automotive interior lighting designs, consumers have placed higher demands on the color, brightness, and adjustment functions of ambient lighting in their vehicles.

[0003] However, traditional interior lighting integrated chips typically incorporate a high-current constant current source to drive the LED chips. Because these integrated chips need to handle the large current driving task, some power consumption flows directly into the chip, causing it to heat up and affecting the stability and reliability of the display device. Furthermore, after the LEDs start operating, temperature changes cause variations in their brightness. If the original control signal is still used to control the corresponding LEDs, the brightness will deviate, resulting in a deviation in the brightness or color of the displayed device. Consequently, the brightness or color of the LEDs may not meet user requirements, leading to a display device that fails to meet user needs.

[0004] Therefore, existing display devices suffer from inaccurate display and poor display performance. Summary of the Invention

[0005] This invention provides a display device and its control method, which improves the display performance of the display device.

[0006] According to one aspect of the present invention, a control method for a display device is provided. The display device includes at least one LED, a controller, at least one first switching unit, a detection constant current source, a second switching unit, an external driving constant current source, a third switching unit, and a sampling module. The LED includes at least one light-emitting diode (LED). The first switching unit is connected in parallel with the LED, the LED is connected between a first power supply and a first terminal of the detection constant current source, the second switching unit is connected between a second terminal of the detection constant current source and a second power supply, the external driving constant current source and the third switching unit are connected in series between the first terminal of the detection constant current source and the second power supply, and the sampling module is connected between the first power supply and the first terminal of the detection constant current source. The controller is connected to the control terminals of the first switching unit, the second switching unit, the third switching unit, and the sampling module, respectively. The method is executed by the controller. The method includes: In the current display control cycle, it is determined whether the currently detected LED bead is in working state based on the control signal of the control terminal of the first switching unit corresponding to the LED bead currently being detected. If the currently detected LED bead is in working condition, then the third switch unit is controlled to open, and the second switch unit is controlled to close. According to the preset detection order of the light-emitting diodes in the currently tested LED beads, the sampling module is controlled to collect the PN junction voltage of the currently tested light-emitting diode in the currently tested LED beads; When the timeout period reaches the preset duration, the PN junction voltage is acquired, and the current temperature of the currently detected LED is determined based on the PN junction voltage. The compensation value corresponding to the currently detected LED is then determined based on the current temperature. The control signal of the first switching unit corresponding to the currently detected light-emitting diode is compensated according to the compensation value, and the first switching unit corresponding to the currently detected light-emitting diode is controlled according to the compensated control signal during the working phase of the current display control cycle.

[0007] Optionally, determining whether the currently detected LED is in a working state based on the control signal of the control terminal of the first switching unit corresponding to the LED in the currently detected LED includes: If the duty cycle of the control signal at the control terminal of the first switching unit corresponding to any LED in the currently tested LED is greater than a set threshold, or if the duty cycle of the control signal at the control terminal of the first switching unit corresponding to all LEDs in the currently tested LED is greater than zero, then the currently tested LED is determined to be in a working state; wherein, the duty cycle of the control signal is the ratio of the pulse width of the first switching unit controlled by the control signal to be turned off to the duration of one cycle of the control signal.

[0008] Optionally, according to a preset detection sequence of the light-emitting diodes in the currently tested LED bead, the sampling module is controlled to acquire the PN junction voltage of the currently tested LED in the currently tested LED bead, including: The LED being tested is determined according to the preset testing order of the LEDs in the currently tested LED beads; The first switching unit corresponding to the currently detected light-emitting diode is turned off, and the remaining first switching units are turned on. The sampling module is controlled to acquire the PN junction voltage of the currently detected LED in the currently detected LED bead.

[0009] Optionally, the LED chip includes at least two light-emitting diodes of different colors; According to the preset detection sequence of the LEDs in the currently tested LED chips, determine the LED to be tested, including: The LED being tested is determined according to the preset testing sequence of the LEDs in the current LED being tested and the LED being tested in the previous display control cycle.

[0010] Optionally, when the timing duration reaches a preset duration, the PN junction voltage is acquired, and the current temperature of the currently detected LED is determined based on the PN junction voltage. A compensation value corresponding to the currently detected LED is then determined based on the current temperature, including: When the preset timeout period is reached, the PN junction voltage is obtained from the sampling module, and the timing restarts. The current temperature of the LED being detected is determined based on the PN junction voltage and the first preset correspondence; wherein, the first preset correspondence is the correspondence between the PN junction voltage and the current temperature of the LED. The compensation value corresponding to the currently detected light-emitting diode is determined based on the current temperature and the second preset correspondence; wherein, the second preset correspondence is the correspondence between the current temperature of the light-emitting diode and the compensation value.

[0011] Optionally, before controlling the first switching unit corresponding to the currently detected light-emitting diode according to the compensated control signal, the method further includes: During the current display control cycle, the second switch unit is turned off, and the third switch unit is turned on. When controlling the first switching unit corresponding to the currently detected light-emitting diode according to the compensated control signal, the method further includes: The first switching unit is controlled according to the control signal corresponding to each of the remaining light-emitting diodes.

[0012] Optionally, the LED chip includes at least two light-emitting diodes of different colors; Controlling the first switching unit corresponding to the currently detected LED according to the compensated control signal, and controlling the corresponding first switching unit according to the control signal for each of the remaining LEDs, including: For the currently detected LED, according to the preset light emission sequence corresponding to the currently detected LED, the corresponding control signals are sequentially output to the corresponding first switching unit, wherein the control signal of the first switching unit corresponding to the currently detected LED is a compensated control signal; For the remaining LEDs, control signals are sequentially output to the corresponding first switching unit according to the preset light emission sequence of the LEDs.

[0013] According to another aspect of the present invention, a display device is provided, the display device comprising at least one LED, a controller, at least one first switching unit, a detection constant current source, a second switching unit, an external driving constant current source, a third switching unit, and a sampling module. The LED includes at least one light-emitting diode (LED). The first switching unit is connected in parallel with the LED, the LED is connected between a first power supply and a first terminal of the detection constant current source, the second switching unit is connected between a second terminal of the detection constant current source and a second power supply, the external driving constant current source and the third switching unit are connected in series between the first terminal of the detection constant current source and the second power supply, and the sampling module is connected between the first power supply and the first terminal of the detection constant current source. The controller is connected to the control terminals of the first switching unit, the second switching unit, the third switching unit, and the sampling module, respectively. The controller is used to execute the control method of the display device according to any embodiment of the present invention.

[0014] Optionally, the lamp bead includes at least two light-emitting diodes with different light-emitting colors; All the light-emitting diodes in the display device are connected in series between the first power supply and the first terminal of the detection constant current source.

[0015] Optionally, the sampling module includes a differential detection circuit and an analog-to-digital conversion circuit; The first terminal of the differential detection circuit is connected to the first power supply, the second terminal of the differential detection circuit is connected to the first terminal of the detection constant current source, and the output terminal of the differential detection circuit is connected to the input terminal of the analog-to-digital conversion circuit. The output of the analog-to-digital converter circuit is connected to the controller.

[0016] The technical solution of this invention, in the current display control cycle, determines whether the currently tested LED is in a working state based on the control signal of the control terminal of the first switching unit corresponding to the LED in the currently tested LED. If the currently tested LED is in a working state, the third switching unit is controlled to open, and the second switching unit is controlled to close, which can ensure the accuracy and effectiveness of the test. Furthermore, it ensures that the LED will not be in a working state during the testing phase, avoiding impact on the LED's emission duration and thus its brightness, which helps ensure the accuracy of the display device's brightness and color, thereby improving the display device's performance. Then, according to the preset detection sequence of the LEDs in the currently tested LEDs, the sampling module is controlled to collect the PN junction voltage of the currently tested LED in the currently tested LED. When the preset timing duration is reached, the PN junction voltage is acquired, and the current temperature of the currently tested LED is determined based on the PN junction voltage. A compensation value corresponding to the currently tested LED is then determined based on the current temperature. The control signal of the first switching unit corresponding to the currently tested LED is compensated based on the compensation value, and during the working phase of the current display control cycle, the first switching unit corresponding to the currently tested LED is controlled based on the compensated control signal. In this way, by compensating for the LED's brightness based on its current temperature, the problem of significant brightness deviation caused by the LED's temperature rising after a period of operation can be avoided, thus improving the LED's luminous effect and consequently enhancing the display performance of the display device. Furthermore, the external driving constant current source is located outside the display device. By using an external driving constant current source to drive the LED, heat generation of the display device can be avoided, thereby improving its stability and reliability.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the circuit structure of a display device provided in an embodiment of the present invention; Figure 2 This is a flowchart of a control method for a display device provided in an embodiment of the present invention; Figure 3 This is a flowchart of another control method for a display device provided in an embodiment of the present invention; Figure 4 This is a flowchart of another control method for a display device provided in an embodiment of the present invention; Figure 5 This is a timing diagram of a display device provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the circuit structure of another display device provided in an embodiment of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] This invention provides a control method for a display device. Figure 1 This is a schematic diagram of the circuit structure of a display device provided in an embodiment of the present invention, for reference. Figure 1The display device includes at least one LED bead 110, a controller 120, at least one first switching unit 130, a detection constant current source 140, a second switching unit 150, a third switching unit 170, and a sampling module 180. The LED bead 110 includes at least one light-emitting diode (LED). The first switching unit 130 is connected in parallel with the LED, and the LED is connected between the first power supply VCC and the first terminal of the detection constant current source 140. The second switching unit 150 is connected between the second terminal of the detection constant current source 140 and the second power supply. An external driving constant current source 160 and the third switching unit 170 are connected in series between the first terminal of the detection constant current source 140 and the second power supply. The sampling module 180 is connected between the first power supply VCC and the first terminal of the detection constant current source 140. The controller 120 is connected to the control terminals of the first switching unit 130, the second switching unit 150, the third switching unit 170, and the sampling module 180, respectively.

[0023] In this configuration, the first power supply VCC can be a positive power supply, and the second power supply can be a negative power supply or ground. Figure 1 The example shows the case where the second power supply is ground (GND), but it is not a limitation.

[0024] For example, the current supplied by the detection constant current source 140 is less than the current supplied by the external driving constant current source 160. The current supplied by the detection constant current source 140 is less than the operating current required for the LED to emit light. The current supplied by the external driving constant current source 160 is greater than or equal to the operating current required for the LED to emit light. That is, when the detection constant current source 140 supplies power to the LED, the LED does not emit light, or emits only a faint light, or flashes, but it will not emit light normally, ensuring that the LED does not overheat. This guarantees the accuracy of the PN junction voltage detection of the LED. When the external driving constant current source 160 supplies power to the LED, the LED emits light. For example, the current supplied by the detection constant current source 140 is less than one-tenth of the operating current required for the LED to emit light.

[0025] An external constant current source 160 is located outside the display device. By using an external constant current source 160 to drive the light-emitting diode (LED) to emit light, heat generation in the display device (e.g., an integrated chip for interior lighting) can be avoided, thereby improving the stability and reliability of the display device.

[0026] Each LED bead 110 includes at least one light-emitting diode (LED), for example, one LED bead 110 may include a red LED, a green LED, and a blue LED, without limitation herein. The first switching unit 130 may include a metal-oxide-semiconductor (MOS) transistor, a bipolar junction transistor (BJT), or other types of transistors, without limitation herein. The second switching unit 150 and the third switching unit 170 may also include MOS transistors or BJTs, without limitation herein.

[0027] The first switch unit 130 is configured to correspond one-to-one with the light-emitting diode (LED). The first switch unit 130 and the LED are connected in parallel, so that when the first switch unit 130 is closed (conducted), the LED does not emit light. When the first switch unit 130 is closed and the third switch unit 170 is closed, the external driving constant current source 160 can supply power to the LED, so that the LED can emit light.

[0028] The control method for the display device is executed by the controller. The controller 120 may include a microcontroller chip, etc., and is not limited thereto. The controller 120 can output control signals to the control terminal of the first switching unit 130. The control signal output to the first switching unit 130 can be a pulse width modulation (PWM) signal. By outputting PWM signals with different duty cycles, the closing time of the first switching unit 130 within a display control cycle can be controlled, thereby controlling the brightness of the corresponding LED. The controller 120 can also control whether the second switching unit 150 and the third switching unit 170 are turned on. When the second switching unit 150 is turned on, the constant current source 140 is detected to supply power to the LED. When the third switching unit 170 is turned on, the externally driven constant current source 160 can supply power to the LED. When the constant current source 140 is detected to supply power to the LED, current flows through the LED, and the sampling module 180 can collect the voltage across the LED, which is the PN junction voltage of the LED.

[0029] Figure 1 The illustration shows a display device including a lamp bead 110, which includes a light-emitting diode (LED), but is not limiting.

[0030] Figure 2 This is a flowchart of a control method for a display device provided in an embodiment of the present invention, referred to as... Figure 2The control methods for display devices include: S210. In the current display control cycle, determine whether the currently detected LED is in working state based on the control signal of the control terminal of the first switching unit corresponding to the LED in the currently detected LED.

[0031] When the display device is turned on, the controller will cyclically execute the display control cycle to control the display device to emit light.

[0032] The currently detected LED can be determined by external commands or by a pre-set detection order. For example, a display device may include four LEDs: LED 1, LED 2, LED 3, and LED 4. If the detection order is LED 1, LED 2, LED 3, and LED 4, and the current display control cycle is the first display control cycle, then the currently detected LED is LED 1. If the current display cycle is the second display control cycle, then the currently detected LED is LED 2.

[0033] Specifically, the control signal at the control terminal of the first switching unit can control whether the first switching unit is closed. Only when the first switching unit is closed can the corresponding LED emit light, i.e., it be in a working state. When the first switching unit is closed, the corresponding LED will not be in a working state. Therefore, based on the control signal at the control terminal of the first switching unit corresponding to the LED, it can be determined whether the corresponding LED is in a working state, and thus whether the currently detected LED bead containing the LED is in a working state.

[0034] For example, when the duty cycle of the control signal is large, it can be determined that the corresponding first switching unit is turned off, that is, the corresponding light-emitting diode is in the working state. Here, the duty cycle of the control signal is the ratio of the duration of the invalid level of the control signal within one display control cycle to the cycle length of one display control cycle. The invalid level is the level that controls the first switching unit to turn off. The invalid level can be low or high, depending on the type of transistor in the first switching unit, and is not limited here.

[0035] S220. If the currently detected LED bead is in working condition, control the third switch unit to open and control the second switch unit to close.

[0036] Specifically, if the LED being tested is currently in operation, the third switching unit is controlled to open (i.e., turn off), preventing the external driving constant current source from supplying power to the LED and thus preventing the LED from operating. The second switching unit is then controlled to close, allowing the detection constant current source to supply power to the LED, facilitating the detection of the LED's PN junction voltage.

[0037] Before testing the LED bead, it is determined whether the LED bead is currently in a working state. If the LED bead is in a working state, the third switch unit is opened, and then the second switch unit is closed. This ensures the accuracy and effectiveness of the test. It also ensures that the LED is not in a working state during the test phase, avoiding any impact on the LED's emission timing and thus its brightness. This helps to ensure the accuracy of the display device's brightness and color, thereby improving the display performance of the display device.

[0038] It should be noted that if the currently detected LED is in a non-working state, it indicates that the third switch unit is in an open state, and the second switch unit is then controlled to close.

[0039] S230. According to the preset detection sequence of the light-emitting diodes in the currently tested LED beads, control the sampling module to collect the PN junction voltage of the currently tested light-emitting diode in the currently tested LED beads.

[0040] The preset detection order of the light-emitting diodes in each LED bead is stored in advance. The preset detection order for different LED beads can be the same or different, and there is no limitation here.

[0041] In each display control cycle, the PN junction voltage of one LED is detected. When the currently detected LED chip includes one LED, the preset detection sequence is to detect the LED in the currently detected LED chip. When the currently detected LED chip includes at least two LEDs, the LED to be detected in the current display control cycle is determined according to the preset detection sequence of all LEDs in the currently detected LED chip; this is the LED to be detected. For example, if an LED chip includes three LEDs, namely LED 1, LED 2, and LED 3, and the preset detection sequence for the currently detected LED chip is LED 1, LED 2, and LED 3, and the current display control cycle is the first display control cycle for detecting the currently detected LED chip, then the LED to be detected is LED 1. In this way, the PN junction voltage of one LED can be detected in each display control cycle, making the non-operating phase of a display control cycle shorter and avoiding interference with the display device's light emission.

[0042] Specifically, based on the preset detection sequence of the LEDs in the currently tested LED bead, the currently tested LED in the currently tested LED bead can be determined. Then, the sampling module is controlled to collect the voltage between the two ends of the currently tested LED in the currently tested LED bead, which is used as the PN junction voltage of the currently tested LED.

[0043] S240. When the timing duration reaches the preset duration, acquire the PN junction voltage, determine the current temperature of the LED being tested based on the PN junction voltage, and determine the corresponding compensation value of the LED being tested based on the current temperature.

[0044] The system begins timing at the start of the display control cycle. Timing restarts whenever the preset duration is reached, and this cycle repeats. This allows the acquisition module to capture the PN junction voltage of the currently detected LED each time the preset duration is reached. This avoids directly acquiring the PN junction voltage of the LED after each acquisition to compensate the control signal of the corresponding first switching unit, reducing the number of compensation operations and minimizing impact on the operating duration. This ensures better LED illumination and ultimately improves the display performance of the device.

[0045] Specifically, if the timing duration reaches the preset duration in the current display control cycle, the PN junction voltage of the currently detected LED is acquired, and the current temperature of the LED is determined based on the PN junction voltage. The corresponding compensation value for the LED is then determined based on the current temperature. The current temperature of the LED can be found by referring to the correspondence between the PN junction voltage and the current temperature of the LED, and the corresponding compensation value can be found by referring to the correspondence between the current temperature of the LED and the compensation value; however, this is not limited here.

[0046] S250. The control signal of the first switching unit corresponding to the currently detected LED is compensated according to the compensation value, and the first switching unit corresponding to the currently detected LED is controlled according to the compensated control signal during the working phase of the current display control cycle.

[0047] Specifically, the control signal of the first switching unit corresponding to the currently detected LED can be added to or multiplied by the corresponding compensation value to obtain the compensated control signal. Alternatively, the duty cycle of the control signal of the first switching unit corresponding to the currently detected LED can be added to or multiplied by the corresponding compensation value, and the resulting duty cycle can be used as the duty cycle of the compensated control signal, thus obtaining the compensated control signal. No limitation is imposed here.

[0048] The first switching unit corresponding to the currently detected LED is controlled according to the compensated control signal, that is, the off-time of the first switching unit corresponding to the currently detected LED is controlled according to the compensated control signal, thereby controlling the light emission time of the currently detected LED.

[0049] After detecting the PN junction voltage and compensating the control signal of the first switching unit corresponding to the currently detected LED based on the compensation value, the system enters the working phase of the current display control cycle. During this phase, the compensated control signal is output to the first switching unit corresponding to the currently detected LED. The compensated control signal controls the off-duration of the first switching unit during the current display control cycle, thereby controlling the LED's brightness. Specifically, the control signal controls the off-duration of the first switching unit, which in turn controls the LED's illumination duration, and consequently, its brightness. This method, by compensating for the LED's brightness based on its current temperature, avoids the problem of significant brightness deviations caused by temperature increases after a period of operation, thus improving the LED's luminous effect and ultimately enhancing the display performance of the display device.

[0050] In this embodiment, during the current display control cycle, the system determines whether the currently tested LED is in operation based on the control signal of the control terminal of the first switching unit corresponding to the LED in the currently tested LED. If the LED is in operation, the third switching unit is opened, and the second switching unit is closed, ensuring the accuracy and effectiveness of the test. Furthermore, it ensures that the LED is not in operation during the testing phase, preventing the LED's emission duration from being affected, thus impacting its brightness. This helps ensure the accuracy of the display device's brightness and color, thereby improving its display performance. Then, according to the preset detection sequence of the LEDs in the currently tested LEDs, the sampling module collects the PN junction voltage of the LED in the currently tested LED. When the preset timing duration is reached, the PN junction voltage is acquired, and the current temperature of the LED is determined based on the PN junction voltage. A compensation value is then determined based on the current temperature. The control signal of the first switching unit corresponding to the LED is compensated based on the compensation value, and during the working phase of the current display control cycle, the first switching unit corresponding to the LED is controlled according to the compensated control signal. In this way, by compensating for the LED's brightness based on its current temperature, the problem of significant brightness deviation caused by the LED's temperature rising after a period of operation can be avoided, thus improving the LED's luminous effect and consequently enhancing the display performance of the display device. Furthermore, the external driving constant current source is located outside the display device. By using an external driving constant current source to drive the LED, heat generation of the display device can be avoided, thereby improving its stability and reliability.

[0051] Based on the above technical solution, optionally, determining whether the currently detected LED is in a working state is based on the control signal of the control terminal of the first switching unit corresponding to the LED in the currently detected LED, including: If the duty cycle of the control signal at the control terminal of the first switching unit corresponding to any LED in the currently tested LED is greater than a set threshold, or if the duty cycle of the control signal at the control terminal of the first switching unit corresponding to all LEDs in the currently tested LED is greater than zero, then the currently tested LED is determined to be in a working state; wherein, the duty cycle of the control signal is the ratio of the pulse width of the first switching unit corresponding to the control signal being turned off to the duration of one cycle of the control signal.

[0052] Specifically, if the duty cycle of the control signal at the control terminal of the first switching unit corresponding to any LED in the currently tested LED bead is greater than a set threshold, it indicates that there is an open first switching unit among all the corresponding first switching units in the currently tested LED bead, and the open time of the first switching unit is relatively long, so the current in the LED may be large. Therefore, there may be an LED in the working state, and the currently tested LED bead is determined to be in the working state. If the duty cycle of the control signal at the control terminal of the first switching unit corresponding to all LEDs in the currently tested LED bead is greater than zero, for example, if the currently tested LED bead includes three LEDs, then all three first switching units corresponding to the three LEDs have a moment of being open. Therefore, all three LEDs in the currently tested LED bead have a moment of current flowing through them. The brightness of the three LEDs is superimposed, causing the currently tested LED bead to emit light, and the currently tested LED bead is in the working state.

[0053] Based on the above technical solutions, Figure 3 This is a flowchart of another control method for a display device provided in an embodiment of the present invention. Optionally, refer to... Figure 3 The control methods for display devices include: S310. In the current display control cycle, determine whether the currently detected LED bead is in working state based on the control signal of the control terminal of the first switching unit corresponding to the LED bead being detected.

[0054] S320. If the currently detected LED bead is in working condition, control the third switch unit to open and control the second switch unit to close.

[0055] S330. Determine the LED to be tested according to the preset testing sequence of the LEDs in the LEDs currently being tested.

[0056] Specifically, if the currently tested LED includes one LED, then that LED is the one being tested. If the currently tested LED includes at least two LEDs, the LED to be tested in the current display control cycle is determined according to the preset testing order of all LEDs in the currently tested LED and the LEDs that have already been tested. Alternatively, the LED to be tested can be determined according to the preset testing order of all LEDs in the currently tested LED and the specific cycle in which the currently tested LED is being tested. No specific limitations are imposed here.

[0057] S340: Control the first switching unit corresponding to the currently detected light-emitting diode to turn off, and control the remaining first switching units to close.

[0058] Specifically, when the display device includes at least two light-emitting diodes (LEDs), all LEDs in the display device are connected in series. By controlling the first switching unit corresponding to the currently detected LED to turn off (i.e., open) and controlling the remaining first switching units to close, the remaining LEDs other than the currently detected LED are short-circuited. This allows the currently detected LED, the detection constant current source, and the second switching unit to form a current loop, enabling the detection of the currently detected LED.

[0059] S350: The control sampling module collects the PN junction voltage of the currently detected LED in the currently detected LED bead.

[0060] S360. When the timing duration reaches the preset duration, acquire the PN junction voltage, determine the current temperature of the LED being tested based on the PN junction voltage, and determine the corresponding compensation value of the LED being tested based on the current temperature.

[0061] S370. The control signal of the first switching unit corresponding to the currently detected LED is compensated according to the compensation value, and the first switching unit corresponding to the currently detected LED is controlled according to the compensated control signal during the working phase of the current display control cycle.

[0062] Based on the above technical solution, optionally, the LED bead includes at least two LEDs of different colors. That is, each LED bead includes at least two LEDs of different colors. For example, each LED bead includes a red LED, a green LED, and a blue LED.

[0063] Optionally, the LED to be tested is determined according to a preset testing sequence among the LEDs currently being tested, including: The LED to be tested is determined according to the preset testing sequence of the LEDs in the current LED test and the LED tested in the previous display control cycle.

[0064] The controller's I / O (input / output) ports are connected to the first switching unit, with one I / O port corresponding to one first switching unit. The controller can determine the previous LED being detected in the previous display control cycle based on the first switching unit that was turned off during the non-working phase (detection phase) of the previous display control cycle.

[0065] For example, each LED includes three LEDs: a first LED, a second LED, and a third LED. The preset detection order of the LEDs in the currently being tested LED is the first LED, the second LED, and the third LED. If the LED detected in the previous display control cycle is not one of the LEDs in the currently being tested LED, then the currently being tested LED is the first LED in the currently being tested LED. For example, if the LED detected in the previous display control cycle was the first LED in the currently being tested LED, then the currently being tested LED is the second LED in the currently being tested LED.

[0066] Based on the above technical solutions, optionally, when the timing duration reaches a preset duration, the PN junction voltage is acquired, and the current temperature of the LED being detected is determined based on the PN junction voltage. Then, the compensation value corresponding to the LED being detected is determined based on the current temperature, including: Step a1: When the timing duration reaches the preset duration, obtain the PN junction voltage from the sampling module and restart the timing.

[0067] Specifically, if the timing duration reaches the preset duration in the current display control cycle, the PN junction voltage of the currently detected LED is obtained from the sampling module. This allows for compensation of the control signal of the first switching unit corresponding to the currently detected LED based on the PN junction voltage, i.e., compensation of the LED's brightness. Timing then restarts, ensuring that the brightness of the detected LED is compensated every preset duration.

[0068] Step a2: Determine the current temperature of the LED being tested based on the PN junction voltage and the first preset correspondence; wherein, the first preset correspondence is the correspondence between the PN junction voltage and the current temperature of the LED.

[0069] Specifically, the first preset correspondence can be stored in the controller in the form of a table or curve. After obtaining the PN junction voltage of the currently detected LED, the PN junction voltage of the currently detected LED is substituted into the first preset correspondence to find and determine the current temperature of the currently detected LED. If the current temperature of the currently detected LED cannot be found directly, an interpolation method can be used. The current temperature of the currently detected LED can be determined by interpolating between two PN junction voltages in the first preset correspondence that are close to the detected PN junction voltage.

[0070] Step a3: Determine the compensation value corresponding to the currently detected LED based on the current temperature and the second preset correspondence; wherein, the second preset correspondence is the correspondence between the current temperature of the LED and the compensation value.

[0071] Specifically, the second preset correspondence can be stored in the controller in the form of a table or curve. After determining the current temperature of the LED being detected, the current temperature of the LED is substituted into the second preset correspondence to find and determine the compensation value corresponding to the LED. If the compensation value corresponding to the LED cannot be found directly, an interpolation method can be used. The compensation value corresponding to the LED can be determined by interpolating the compensation values ​​corresponding to two temperatures close to the current temperature in the second preset correspondence.

[0072] Based on the above technical solutions, Figure 4 This is a flowchart of another control method for a display device provided in an embodiment of the present invention. Optionally, refer to... Figure 4 The control methods for display devices include: S410. In the current display control cycle, determine whether the currently detected LED is in working state based on the control signal of the control terminal of the first switching unit corresponding to the LED in the currently detected LED.

[0073] S420. If the currently detected LED bead is in working condition, control the third switch unit to open and control the second switch unit to close.

[0074] S430. According to the preset detection sequence of the light-emitting diodes in the currently tested LED beads, control the sampling module to collect the PN junction voltage of the currently tested light-emitting diode in the currently tested LED beads.

[0075] S440. When the timing duration reaches the preset duration, acquire the PN junction voltage, determine the current temperature of the LED being tested based on the PN junction voltage, and determine the corresponding compensation value for the LED being tested based on the current temperature.

[0076] S450. The control signal of the first switching unit corresponding to the currently detected light-emitting diode is compensated according to the compensation value, and during the working phase of the current display control cycle, the second switching unit is turned off and the third switching unit is turned off.

[0077] Specifically, after compensating the control signal of the first switching unit corresponding to the currently detected LED, the system enters the working phase of the current display control cycle. During the working phase of the current display control cycle, the second switching unit is first turned off, and the third switching unit is then turned on, so that the detection constant current source no longer supplies power to the LED. Instead, an external driving constant current source supplies power to the LED, thus meeting the LED's light-emitting requirements.

[0078] S460. Control the first switching unit corresponding to the currently detected light-emitting diode according to the compensated control signal, and control the corresponding first switching unit according to the control signal corresponding to each of the remaining light-emitting diodes.

[0079] Specifically, while controlling the first switching unit corresponding to the currently detected light-emitting diode according to the compensated control signal, the first switching unit corresponding to each of the other light-emitting diodes is also controlled according to the control signal corresponding to each of the other light-emitting diodes. This allows each first switching unit to turn off for a corresponding duration according to the corresponding control signal, thereby enabling each light-emitting diode to display the corresponding target brightness.

[0080] Furthermore, at the end of the current display control cycle, the controller can close all first switch units and turn off the third switch unit. By determining whether the currently detected LED is in working state based on the control signal of the control terminal of the first switch unit corresponding to the LED in each display control cycle, and if the currently detected LED is in working state, the controller opens the third switch unit and closes the second switch unit. This avoids situations where the detected LED is in working state due to incomplete shutdown of the third switch unit or incomplete closure of the first switch unit, thus improving the accuracy of display device control.

[0081] Based on the above technical solution, optionally, the lamp bead includes at least two light-emitting diodes of different colors; The first switching unit corresponding to the currently detected LED is controlled according to the compensated control signal, and the first switching unit corresponding to each of the remaining LEDs is controlled according to the control signal, including: Step b1: For the currently tested LED, according to the preset light emission sequence corresponding to the currently tested LED, output the corresponding control signals to the corresponding first switching unit in sequence. The control signal of the first switching unit corresponding to the currently tested LED is the compensated control signal.

[0082] In this configuration, within the same LED, the emission phases of any two adjacent LEDs overlap in the preset emission sequence. The emission phase of an LED refers to the phase during which a control signal is output to the corresponding first switching unit during the operating phase. During this emission phase, the LED's emission duration is equal to the off duration of the corresponding first switching unit. If the duty cycle of the control signal for the first switching unit is 100%, meaning the first switching unit remains off during the corresponding emission phase, the LED will emit light during that phase. If the duty cycle of the control signal for the first switching unit is 0%, meaning the first switching unit remains closed during the corresponding emission phase, the LED will not emit light during that phase.

[0083] Specifically, each LED corresponds to a preset light-emitting sequence. For the currently tested LED, according to the preset light-emitting sequence, the corresponding control signals are sequentially output to the corresponding first switching unit, causing the LEDs in the currently tested LED to emit light sequentially. Moreover, within the same LED, the light-emitting phases of every two adjacent LEDs in the preset light-emitting sequence overlap, achieving staggered light emission of the LEDs in the currently tested LED. This reduces the impact on the first and second power supplies, which is beneficial to improving the display reliability and stability of the display device, and further enhances the display performance of the display device.

[0084] Step b2: For the remaining LEDs, output the corresponding control signals to the corresponding first switching unit in sequence according to the preset light emission order of the LEDs.

[0085] In the same LED, the light-emitting stages of every two adjacent LEDs overlap in the preset light-emitting sequence.

[0086] Specifically, each LED corresponds to a preset light-emitting sequence. The preset light-emitting sequences for different LEDs can be the same or different. For example, each LED includes three LEDs: a first LED, a second LED, and a third LED. The preset light-emitting sequence for each LED is, for example, the first LED, the second LED, and the third LED. By sequentially outputting corresponding control signals to the corresponding first switching unit according to the preset light-emitting sequence of the LEDs, the LEDs in the LEDs emit light sequentially. Furthermore, within the same LED, the light-emitting phases of every two adjacent LEDs in the preset light-emitting sequence overlap, achieving staggered light emission of the LEDs in the LEDs. This reduces the impact on the first and second power supplies, improving the display reliability and stability of the display device, and further enhancing its display performance.

[0087] For example, Figure 5This is a timing diagram of a display device provided in an embodiment of the present invention, such as... Figure 5 As shown, for example, the display device includes a lamp bead, which includes three light-emitting diodes, namely a first light-emitting diode LED0, a second light-emitting diode LED1, and a third light-emitting diode LED2. The preset detection order in the lamp bead is the first light-emitting diode LED0, the second light-emitting diode LED1, and the third light-emitting diode LED2. The preset light emission order in the lamp bead is the first light-emitting diode LED0, the second light-emitting diode LED1, and the third light-emitting diode LED2.

[0088] After the display device is powered on, the display control cycle begins execution, and timing starts. During the detection phase T0 (non-light-emitting phase) of the first display control cycle t1, the first light-emitting diode LED0 is the currently detected light-emitting diode. The controller controls the first switching unit corresponding to the first light-emitting diode LED0 to turn off, while the first switching units corresponding to the other light-emitting diodes are closed (conducted). The controller detects the first light-emitting diode LED0 and collects its PN junction voltage. If the timing duration reaches the preset duration at this time, the controller acquires the PN junction voltage of the first light-emitting diode LED0, determines the current temperature based on the PN junction voltage of the first light-emitting diode LED0, determines a compensation value based on the current temperature, compensates the control signal of the first switching unit corresponding to the first light-emitting diode LED0, and restarts timing. Then, in the first display control cycle t1, during the light-emitting phase T1, in the first sub-phase T11 (the light-emitting phase of the first LED0), a compensated control signal is sent to the first switching unit corresponding to the first LED0, causing the first switching unit to turn off for a corresponding duration (the duration corresponding to the duty cycle of the compensated control signal). The first LED0 then emits light for the corresponding duration, thereby controlling its brightness. In the second sub-phase T12 (the light-emitting phase of the second LED1), the controller sends a control signal corresponding to the second LED1 to the first switching unit corresponding to the second LED1, causing the second LED1 to emit light for the corresponding duration. In the third sub-phase T13 (the light-emitting phase of the third LED2), the controller sends a control signal corresponding to the third LED2 to the first switching unit corresponding to the third LED2, causing the third LED2 to emit light for the corresponding duration. Furthermore, the first sub-stage T11 overlaps with the second sub-stage T12, and the second sub-stage T12 overlaps with the third sub-stage T13. This results in overlapping light-emitting stages for every two adjacent LEDs in the same LED chip within the preset light-emitting sequence. This staggered light-emitting of the LEDs within the same LED chip reduces the impact on the first and second power supplies.

[0089] During the detection phase T0 (non-light-emitting phase) of the second display control cycle t2, the second LED (LED1) is the currently detected LED. The controller controls the first switching unit corresponding to LED1 to turn off, while the first switching units corresponding to the other LEDs are closed (conducting). The controller detects LED1 and acquires its PN junction voltage. If the timing duration reaches the preset duration, the controller acquires the PN junction voltage of LED1, determines the current temperature based on this voltage, determines a compensation value based on the current temperature, compensates the control signal of the first switching unit corresponding to LED1, and restarts the timing. Then, during the light-emitting phase T1 of the second display control cycle t2, in the first sub-phase T11, the control signal corresponding to LED0 is sent to the first switching unit corresponding to LED0, causing the first switching unit corresponding to LED0 to turn off for the corresponding duration. LED0 then emits light for the corresponding duration, thereby controlling the brightness of LED0. In the second sub-stage T12, the controller sends a compensated control signal to the first switching unit corresponding to the second LED1, causing the second LED1 to emit light for the corresponding duration. In the third sub-stage T13, the controller sends a control signal corresponding to the third LED2 to the first switching unit corresponding to the third LED2, causing the third LED2 to emit light for the corresponding duration.

[0090] In the detection phase T0 (non-light-emitting phase) of the third display control cycle t3, the third LED (LED2) is the currently detected LED. The controller controls the first switching unit corresponding to the third LED (LED2) to turn off, while the first switching units corresponding to the other LEDs are closed (conducting). The controller then detects the third LED (LED2) and acquires its PN junction voltage. If the timing duration reaches the preset duration, the controller acquires the PN junction voltage of the third LED (LED2), determines the current temperature based on this voltage, determines a compensation value based on the current temperature, compensates the control signal of the first switching unit corresponding to the third LED (LED2), and restarts the timing. Then, in the light-emitting phase T1 of the second display control cycle t2, in the first sub-phase T11, the control signal corresponding to the first LED (LED0) is sent to the first switching unit corresponding to the first LED (LED0), causing the first switching unit corresponding to the first LED (LED0) to turn off for the corresponding duration. The first LED (LED0) then emits light for the corresponding duration, thereby controlling the brightness of the first LED (LED0). In the second sub-stage T12, the controller sends a control signal to the first switching unit corresponding to the second LED1, causing the second LED1 to emit light for a specified duration. In the third sub-stage T13, the controller sends a compensated control signal to the first switching unit corresponding to the third LED2, causing the third LED2 to emit light for a specified duration.

[0091] Each I / O port of the controller is connected to a first switch unit, so the corresponding control signal can be output to different first switch units at the same time, and steps b1 and b2 can be executed simultaneously.

[0092] Furthermore, the sampling module is also connected to the controller's I / O port, allowing the control of the first switching unit and the acquisition of the PN junction voltage to be performed using the same controller, thus saving resources.

[0093] This invention also provides a display device, see reference. Figure 1The display device includes at least one LED bead 110, a controller 120, at least one first switching unit 130, a detection constant current source 140, a second switching unit 150, an external driving constant current source 160, a third switching unit 170, and a sampling module 180. The LED bead 110 includes at least one light-emitting diode (LED). The first switching unit 130 is connected in parallel with the LED, and the LED is connected between the first power supply VCC and the first terminal of the detection constant current source 140. The second switching unit 150 is connected between the second terminal of the detection constant current source 140 and the second power supply. The external driving constant current source 160 and the third switching unit 170 are connected in series between the first terminal of the detection constant current source 140 and the second power supply. The sampling module 180 is connected between the first power supply VCC and the first terminal of the detection constant current source 140. The controller 120 is connected to the control terminals of the first switching unit 130, the second switching unit 150, the third switching unit 170, and the sampling module 180, respectively.

[0094] The controller 120 is used to execute the control method of the display device provided in any embodiment of the present invention.

[0095] The display device can be an automotive interior display device, a display screen, or other display devices, and is not limited thereto. Since the controller 120 in the display device of this embodiment is used to execute the control method of the display device provided in any embodiment of the present invention, the display device of this embodiment has the same beneficial effects as the control method of the display device provided in any embodiment of the present invention.

[0096] Figure 6 This is a schematic diagram of the circuit structure of another display device provided in an embodiment of the present invention. Optionally, refer to... Figure 6 The LED 110 includes at least two light-emitting diodes (LEDs) of different colors. All light-emitting diodes (LEDs) in the display device are connected in series between the first power supply VCC and the first terminal of the detection constant current source 140.

[0097] For example, such as Figure 6 As shown, the display device includes multiple light-emitting diodes (LEDs), namely, LED0 (first LED), LED1 (second LED), ..., LEDm (m-th LED). m Where m is an integer greater than 1. For example, three light-emitting diodes (LEDs) form a lamp bead 110. By connecting multiple LEDs in series, the brightness of the display device can be increased, thus improving the user experience.

[0098] Optionally, refer to Figure 6 The sampling module includes a differential detection circuit 181 and an analog-to-digital conversion circuit 182; The first terminal of the differential detection circuit 181 is connected to the first power supply VCC, the second terminal of the differential detection circuit 181 is connected to the first terminal of the detection constant current source 140, and the output terminal of the differential detection circuit 181 is connected to the input terminal of the analog-to-digital conversion circuit 182. The output of the analog-to-digital converter circuit 182 is connected to the controller 120.

[0099] The differential detection circuit 181 may include a differential detection chip, and the analog-to-digital conversion circuit 182 may include an analog-to-digital conversion chip.

[0100] Specifically, the differential detection circuit 181 can detect the differential voltage between the first power supply VCC and the first terminal of the detection constant current source 140. During the detection phase of a display control cycle, only the first switching unit corresponding to one LED is turned off, so that only one LED is connected between the first power supply VCC and the first terminal of the detection constant current source 140, so that the differential detection circuit 181 can detect the PN junction voltage of the LED.

[0101] The analog-to-digital converter circuit 182 can convert the PN junction voltage output by the differential detection circuit 181 into an analog-to-digital value and output the corresponding digital value to the controller 120, so that the controller 120 can receive the PN junction voltage.

[0102] During the detection phase, after the controller 120 controls the first switching unit 130 to turn off, it can trigger the differential detection circuit 181, enabling the differential detection circuit 181 to detect the PN junction voltage of the currently detected LED. Each time the preset timing period is reached, the controller can obtain the detected PN junction voltage from the analog-to-digital conversion circuit 182, and thus compensate the control signal of the first switching unit corresponding to the currently detected LED based on the detected PN junction voltage.

[0103] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0104] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A control method for a display device, characterized in that, The display device includes at least one LED, a controller, at least one first switching unit, a detection constant current source, a second switching unit, a third switching unit, and a sampling module. The LED includes at least one light-emitting diode (LED). The first switching unit is connected in parallel with the LED, and the LED is connected between a first power supply and a first terminal of the detection constant current source. The second switching unit is connected between a second terminal of the detection constant current source and a second power supply. An external driving constant current source is connected in series with the third switching unit between the first terminal of the detection constant current source and the second power supply. The sampling module is connected between the first power supply and the first terminal of the detection constant current source. The controller is connected to the control terminals of the first switching unit, the second switching unit, the third switching unit, and the sampling module. The method is executed by the controller; the method includes: In the current display control cycle, it is determined whether the currently detected LED bead is in working state based on the control signal of the control terminal of the first switching unit corresponding to the LED bead currently being detected. If the currently detected LED bead is in working condition, then the third switch unit is controlled to open, and the second switch unit is controlled to close. According to the preset detection order of the light-emitting diodes in the currently tested LED beads, the sampling module is controlled to collect the PN junction voltage of the currently tested light-emitting diode in the currently tested LED beads; When the timeout period reaches the preset duration, the PN junction voltage is acquired, and the current temperature of the currently detected LED is determined based on the PN junction voltage. The compensation value corresponding to the currently detected LED is then determined based on the current temperature. The control signal of the first switching unit corresponding to the currently detected light-emitting diode is compensated according to the compensation value, and the first switching unit corresponding to the currently detected light-emitting diode is controlled according to the compensated control signal during the working phase of the current display control cycle.

2. The method according to claim 1, characterized in that, Determining whether the currently detected LED is in a working state based on the control signal from the control terminal of the first switching unit corresponding to the LED in the currently detected LED includes: If the duty cycle of the control signal at the control terminal of the first switching unit corresponding to any LED in the currently tested LED is greater than a set threshold, or if the duty cycle of the control signal at the control terminal of the first switching unit corresponding to all LEDs in the currently tested LED is greater than zero, then the currently tested LED is determined to be in a working state; wherein, the duty cycle of the control signal is the ratio of the pulse width of the first switching unit controlled by the control signal to be turned off to the duration of one cycle of the control signal.

3. The method according to claim 1, characterized in that, According to the preset detection sequence of the light-emitting diodes in the currently tested LED beads, the sampling module is controlled to collect the PN junction voltage of the currently tested light-emitting diode in the currently tested LED beads, including: The LED being tested is determined according to the preset testing order of the LEDs in the currently tested LED beads; The first switching unit corresponding to the currently detected light-emitting diode is turned off, and the remaining first switching units are turned on. The sampling module is controlled to acquire the PN junction voltage of the currently detected LED in the currently detected LED bead.

4. The method according to claim 3, characterized in that, The LED chip includes at least two light-emitting diodes of different colors; According to the preset detection sequence of the LEDs in the currently tested LED chips, determine the LED to be tested, including: The LED being tested is determined according to the preset testing sequence of the LEDs in the current LED being tested and the LED being tested in the previous display control cycle.

5. The method according to claim 1, characterized in that, When the preset timeout period is reached, the PN junction voltage is acquired, and the current temperature of the currently detected LED is determined based on the PN junction voltage. Then, a compensation value corresponding to the currently detected LED is determined based on the current temperature, including: When the preset timeout period is reached, the PN junction voltage is obtained from the sampling module, and the timing restarts. The current temperature of the LED being detected is determined based on the PN junction voltage and the first preset correspondence; wherein, the first preset correspondence is the correspondence between the PN junction voltage and the current temperature of the LED. The compensation value corresponding to the currently detected light-emitting diode is determined based on the current temperature and the second preset correspondence; wherein, the second preset correspondence is the correspondence between the current temperature of the light-emitting diode and the compensation value.

6. The method according to claim 1, characterized in that, Before controlling the first switching unit corresponding to the currently detected light-emitting diode according to the compensated control signal, the method further includes: During the current display control cycle, the second switch unit is turned off, and the third switch unit is turned on. When controlling the first switching unit corresponding to the currently detected light-emitting diode according to the compensated control signal, the method further includes: The first switching unit is controlled according to the control signal corresponding to each of the remaining light-emitting diodes.

7. The method according to claim 6, characterized in that, The LED chip includes at least two light-emitting diodes of different colors; Controlling the first switching unit corresponding to the currently detected LED according to the compensated control signal, and controlling the corresponding first switching unit according to the control signal for each of the remaining LEDs, including: For the currently detected LED, according to the preset light emission sequence corresponding to the currently detected LED, the corresponding control signals are sequentially output to the corresponding first switching unit, wherein the control signal of the first switching unit corresponding to the currently detected LED is a compensated control signal; For the remaining LEDs, control signals are sequentially output to the corresponding first switching unit according to the preset light emission sequence of the LEDs.

8. A display device, characterized in that, The display device includes at least one LED, a controller, at least one first switching unit, a detection constant current source, a second switching unit, a third switching unit, and a sampling module. The LED includes at least one light-emitting diode (LED). The first switching unit is connected in parallel with the LED, and the LED is connected between a first power supply and a first terminal of the detection constant current source. The second switching unit is connected between a second terminal of the detection constant current source and a second power supply. An external driving constant current source is connected in series with the third switching unit between the first terminal of the detection constant current source and the second power supply. The sampling module is connected between the first power supply and the first terminal of the detection constant current source. The controller is connected to the control terminals of the first switching unit, the second switching unit, the third switching unit, and the sampling module. The controller is used to execute the control method of the display device according to any one of claims 1-7.

9. The display device according to claim 8, characterized in that, The LED chip includes at least two LEDs with different light-emitting colors; All the light-emitting diodes in the display device are connected in series between the first power supply and the first terminal of the detection constant current source.

10. The display device according to claim 8, characterized in that, The sampling module includes a differential detection circuit and an analog-to-digital conversion circuit; The first terminal of the differential detection circuit is connected to the first power supply, the second terminal of the differential detection circuit is connected to the first terminal of the detection constant current source, and the output terminal of the differential detection circuit is connected to the input terminal of the analog-to-digital conversion circuit. The output of the analog-to-digital converter circuit is connected to the controller.

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