A port voltage stabilizing method and system for an LED display screen

Abstract

The application provides a port voltage stabilizing method for an LED display screen, comprising the following steps: detecting the lamp point opening voltage of the output port of each lamp point; setting the pre-opening voltage stabilizing voltage fine tuning gear of each lamp point according to the lamp point opening voltage; during normal display, adjusting the voltage stabilizing voltage of the output port of each lamp point according to the pre-opening voltage stabilizing voltage fine tuning gear before scanning opening of each row; and setting the port voltage of the output port of all lamp points to the same preset voltage value at the same time after the output port is closed. The application detects the lamp point opening voltage and sets different pre-opening voltage stabilizing voltage values for each lamp point, thereby improving the low gray display consistency and solving the low gray display problems such as low gray mottling; and the port voltage is rapidly pulled down to the same voltage after the port is closed, so as to reduce the closing response difference caused by the LED opening voltage difference.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED display driving, in particular to a port voltage stabilizing method and system for an LED display screen. BACKGROUND

[0002] With the continuous development of LED lighting display technology, LED lighting products have been widely used in the fields of stage lighting and city landscape lighting due to their long service life, energy saving, environmental protection and pure color, and the demand for LED lighting in the society is also increasing.

[0003] According to the scanning mode of the LED display screen, it can be divided into dynamic screen and static screen. The static screen is that each scanning line is turned on at the same time, and each LED lamp is controlled by different drive output ports. Therefore, more drive chips are needed to control, and the wiring difficulty of the display screen substrate is also increased. The dynamic screen displays only one line at a certain time, then displays the next line at the next time, and displays all lines, and then displays the first line, and so on. The whole picture is displayed in a cycle. That is, in the dynamic screen display, multiple LEDs share the same drive port and display in different intervals in a unit time. This method takes advantage of the visual retention of the human eye. For example, a 4-scan LED display screen is composed of 4 lines of time-sharing display; a diagonal stripe is composed of 4 lines, and each line lights up one LED lamp. In the application of the dynamic screen, when the display refresh rate is low, the image will flicker and jitter, and long-time watching will cause eye fatigue.

[0004] The picture displayed by the LED display screen is displayed by controlling the different brightness of the red, green and blue light points in each pixel point, so as to display different colors and restore the picture seen by our eyes. The color restoration function of the LED display screen is not ideal as seen by our eyes, that is, no matter how superior the performance of the display screen is, there is always color difference, and the color seen through the display screen is always not the true color of the image. The main reason is that the brightness level of the red, green and blue display in the LED lamp is limited. For example, the highest gray level of the current LED display screen is 65536 levels, and the corresponding gray data is 16 bits.

[0005] In the traditional multi-channel constant current LED drive chip, the PWM method is usually used for display control. By controlling the on / off time of the LED, the display effect of different gray brightness is achieved. The on / off time of the LED is usually controlled by the gray clock. The higher the frequency of the gray clock, the smaller the minimum opening width. In the case that the display time per frame and the number of scanning lines are constant, the number of pulses of the gray clock is more. Therefore, the higher the frequency, the more gray clocks allocated to each line, that is, the higher the gray level of the display image.

[0006] With the continuous development of display technology, the requirements for display screens are also getting higher and higher. In order to meet the demand for low gray display consistency in high gray level, the dynamic response consistency of the port is particularly important to low gray display, because the smaller the PWM opening width, the greater the influence of the dynamic response speed on the constant current value of the port. The LED display screen driving circuit usually uses a voltage stabilizing circuit to improve the port response speed. The traditional voltage stabilizing circuit applies the same voltage stabilizing voltage to all channels (light points), but the opening voltage of different light points on the LED display screen often has differences, which is easy to cause the dynamic response inconsistency of the port in the chip and between the chips. The dynamic response inconsistency of the port will cause low gray mottling and other display problems on the LED display screen. SUMMARY

[0007] The present application aims at the low gray mottling and other display problems caused by the dynamic response inconsistency of the port of the existing LED display screen driving circuit, and provides a port voltage stabilizing method for an LED display screen, so as to improve the low gray display consistency without changing the constant current loop, solve the low gray mottling and other low gray display problems, and achieve the purpose of higher LED display screen picture restoration.

[0008] The present application provides a port voltage stabilizing method for an LED display screen, comprising the following steps:

[0009] Step S1, detecting the light point opening voltage of the output port of each light point;

[0010] Step S2, setting the opening pre-stabilizing voltage fine tuning gear of each light point according to the light point opening voltage;

[0011] Step S3, during normal display, before each row scanning opening, adjusting the voltage stabilizing voltage of the output port of each light point according to the opening pre-stabilizing voltage fine tuning gear; and

[0012] Step S4, after the output port is closed, setting the port voltage of the output port of all light points to the same preset voltage value at the same time.

[0013] In the port voltage stabilizing method for an LED display screen provided by the present application, step S2 comprises:

[0014] Step S21, setting a detection voltage Vf_test, a lower limit of the detection voltage Vf_test-a and an upper limit of the detection voltage Vf_test+a;

[0015] Step S22, judging whether the light point opening voltage is greater than the lower limit of the detection voltage and less than the upper limit of the detection voltage, and if so, setting the opening pre-stabilizing voltage fine tuning gear of the light point according to the difference between the detection voltage and the light point opening voltage.

[0016] In the port voltage stabilizing method for the LED display screen, if the lamp point opening voltage is less than the lower limit of the detection voltage or greater than the upper limit of the detection voltage, the detection voltage is adjusted to be one step lower or one step higher, then the next lamp point is set, and after the scanning of all the lamp points is completed, the scanning is repeated until the pre-opening voltage fine adjustment step setting of all the lamp points is completed.

[0017] In the port voltage stabilizing method for the LED display screen, it also includes judging whether the lamp point opening voltage is greater than the highest detection voltage or less than the lowest detection voltage, if yes, the lamp point is set as an abnormal lamp point.

[0018] According to another aspect of the present application, a port voltage stabilizing system for an LED display screen is also provided, comprising:

[0019] a sampling module for detecting the lamp point opening voltage of the output port of each lamp point;

[0020] a setting module for setting the pre-opening voltage fine adjustment step of each lamp point according to the lamp point opening voltage;

[0021] a voltage stabilizing module for adjusting the voltage stabilizing voltage of the output port of each lamp point according to the pre-opening voltage fine adjustment step when each row is scanned to open normally, and setting the port voltage of the output port of all the lamp points to the same preset voltage value after the output port is closed.

[0022] In the port voltage stabilizing system for the LED display screen, the setting module comprises:

[0023] a setting unit for setting the detection voltage Vf_test, the lower limit of the detection voltage Vf_test-a and the upper limit of the detection voltage Vf_test+a;

[0024] a judging unit for judging whether the lamp point opening voltage is greater than the lower limit of the detection voltage and less than the upper limit of the detection voltage, if yes, setting the pre-opening voltage fine adjustment step of the lamp point according to the difference between the detection voltage and the lamp point opening voltage.

[0025] In the port voltage stabilizing system for the LED display screen, if the lamp point opening voltage is less than the lower limit of the detection voltage or greater than the upper limit of the detection voltage, the detection voltage is adjusted to be one step lower or one step higher, then the next lamp point is set, and after the scanning of all the lamp points is completed, the scanning is repeated until the pre-opening voltage fine adjustment step setting of all the lamp points is completed.

[0026] In the port voltage stabilizing system for the LED display screen, the setting module further comprises a lamp point abnormality detection unit configured to determine whether the lamp point turn-on voltage is greater than the highest detection voltage or less than the lowest detection voltage, and if so, set the lamp point as an abnormal lamp point.

[0027] According to a further aspect of the present application, there is also provided an LED display screen driving apparatus comprising at least one processor; and a memory connected with the at least one processor in communication; wherein the memory stores instructions executable by the one processor, and the instructions are executed by the at least one processor to cause the at least one processor to perform the port voltage stabilizing method for the LED display screen as described above.

[0028] According to a further aspect of the present application, there is also provided a non-transitory computer readable storage medium storing computer instructions for causing a computer to perform the port voltage stabilizing method for the LED display screen as described above.

[0029] The embodiments of the present application have the following beneficial effects: the port voltage stabilizing method for the LED display screen provided by the present application improves the low-gray display consistency by detecting the lamp point turn-on voltage and setting different pre-turn-on voltage values for each lamp point, and solves the low-gray display problems such as low-gray mura; and the port voltage is rapidly pulled down to the same voltage after the port is closed, so as to reduce the closing response difference caused by the LED turn-on voltage difference. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0031] Figure 1 The figure shows the influence of the port turn-on voltage difference in the prior art voltage stabilizing method on the port dynamic response;

[0032] Figure 2 The figure shows the flow chart of the port voltage stabilizing method for the LED display screen provided by an embodiment of the present application;

[0033] Figure 3 The figure shows Figure 2 The figure shows the flow chart of the setting of the pre-turn-on voltage fine tuning gear in the lamp point turn-on method;

[0034] Figure 4 The figure shows the schematic diagram of the adaptive lamp point turn-on voltage stabilizing of the present application;

[0035] Figure 5 Fig. 1 is a schematic diagram of a port voltage stabilizing system for an LED display screen according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0037] In the prior art, the voltage stabilizing module controls the port voltage before and after PWM opening at a preset voltage stabilizing value through timing control to improve the port response speed and reduce the high and low gray coupling. However, as the PWM opening width decreases, the influence of the difference in lamp opening voltage on the low gray display effect is also more and more obvious. For example, Figure 1 As shown in Fig. 1, when the LED opening voltages VF are different but the pre-opening voltage stabilizing voltage Vstb is set to be the same, there is a significant difference in the opening dynamic response, and the opening dynamic response time difference Δt1 is theoretically calculated as shown in the following formula 1-1:

[0038] Δt1 = CL*(VF2-VF1) / Iout (1-1);

[0039] At the same time, there is also a significant difference in the closing dynamic response, and the closing dynamic response time difference Δt2 is theoretically calculated as shown in the following formula 1-2:

[0040] Δt2 = 2*CL*(VF2-VF1) / Iout (1-2);

[0041] Wherein, CL is the port parasitic capacitance, and Iout is the port constant current. It can be known from the formulas 1-1 and 1-2 that when the port parasitic capacitance is larger and the port constant current is smaller, the influence of the difference in LED opening voltage VF2-VF1 on the port opening / closing response time is greater.

[0042] Figure 2 Fig. 2 is a flowchart of a port voltage stabilizing method for an LED display screen according to an embodiment of the present application. As shown in Fig. 2, Figure 2 The port voltage stabilizing method for an LED display screen provided by the present application includes the following steps:

[0043] Step S1, detecting the lamp opening voltage of the output port of each lamp.

[0044] Specifically, in an embodiment of the present application, since the turn-on voltage of each lamp point is different, the turn-on voltage of the output port of each lamp point is first sampled by the ADC sampling module and the sampling result is fed back to the setting module.

[0045] Step S2, according to the turn-on voltage of the lamp point, setting the pre-turn-on voltage fine tuning gear of each lamp point.

[0046] Specifically, in an embodiment of the present application, after detecting the turn-on voltage of each lamp point, the pre-turn-on voltage fine tuning gear of each lamp point is set according to the different turn-on voltage, so as to set the pre-turn-on voltage of each lamp point according to the actual situation and ensure the consistency of the dynamic response before turning on.

[0047] Further, as shown in the following, the pre-turn-on voltage fine tuning gear of each lamp point is set by the following method: Figure 3

[0048] (1) setting the detection line scan s(x), the detection number num(n) and the RGB voltage stabilizer Vstb gear, controlling the output port of all the lamp points to turn on;

[0049] (2) setting the detection voltage vf_test, the detection range vf_test±a, and the detection port y=0;

[0050] (3) setting the detection port as out(y);

[0051] (4) detecting the turn-on voltage of the out(y) port as vout;

[0052] (5) judging vout: if vout is less than the lowest detection voltage, judging the lamp point abnormal, and outputting the detection result as the lowest gear output lamp point abnormal; if vout is greater than the highest detection voltage, judging the lamp point abnormal, and outputting the detection result as the highest gear output lamp point abnormal; if vout is greater than the lowest detection voltage and less than vf_test-a, the turn-on voltage of this port is lower than the lower limit of the detectable range, adjusting vf_test by one gear lower; if vout is greater than vf_test-a and less than vf_test+a, the turn-on voltage of this port is within the detection range, calculating the fine tuning gear of the output port according to the difference between vf_test and vout; if vout is less than the highest detection voltage and greater than vf_test+a, the turn-on voltage of this port is higher than the upper limit of the detectable range, adjusting vf_test by one gear higher;

[0053] (6) judging whether y is the number of lamp points, if not, setting y=y+1 and returning to step (4) to detect the next port;

[0054] ​(7) after the scanning of a row of lamp points is completed, it is judged whether x is the set row scanning number, if not, x is set to x+1 and the step (3) is returned to detect the next row of lamp points;

[0055] (8) after the scanning of all rows is completed, it is judged whether n is the set scanning number, if not, n is set to n+1 and the step (3) is returned to detect all lamp points in the next round.

[0056] As shown in the figure, if the turn-on voltage of a certain lamp point is not in the detection voltage range, the detection voltage is adjusted (one step up or one step down according to the situation), and the adjusted detection voltage is used to judge when detecting the next lamp point, so that the turn-on pre-stabilized voltage fine adjustment position of all lamp points can be completed through multiple adjustments. Therefore, the step S2 comprises: Figure 3

[0057] Step S21, setting the detection voltage Vf_test, the lower limit of the detection voltage Vf_test-a and the upper limit of the detection voltage Vf_test+a;

[0058] Step S22, judging whether the lamp point turn-on voltage is greater than the lower limit of the detection voltage and less than the upper limit of the detection voltage, if yes, setting the turn-on pre-stabilized voltage fine adjustment position of the lamp point according to the difference between the detection voltage and the lamp point turn-on voltage.

[0059] Further, if the lamp point turn-on voltage is less than the lower limit of the detection voltage or greater than the upper limit of the detection voltage, the detection voltage is adjusted one step down or one step up, the next lamp point is continuously set, and the scanning is repeated until the turn-on pre-stabilized voltage fine adjustment position setting of all lamp points is completed after the scanning of all lamp points is completed.

[0060] Further, it further comprises judging whether the lamp point turn-on voltage is greater than the highest detection voltage or less than the lowest detection voltage, if yes, setting the lamp point as an abnormal lamp point.

[0061] Step S3, during normal display, before the scanning of each row, the turn-on pre-stabilized voltage fine adjustment position is used to adjust the stabilized voltage of the output port of each lamp point.

[0062] Specifically, in an embodiment of the present application, after the turn-on pre-stabilized voltage fine adjustment position setting of all lamp points is completed, during normal display, only the turn-on pre-stabilized voltage fine adjustment position is used to set the stabilized voltage of the output port of the lamp point, so that different stabilized voltages of different lamp points can be realized, thereby the low gray display consistency can be improved and the low gray display problems such as low gray mottling can be solved.

[0063] Step S4, after the output port is closed, the port voltage of the output port of all lamp points is simultaneously set to the same preset voltage value. ​

[0064] Specifically, in an embodiment of the present application, after the port is closed, the port voltage is rapidly set to a same preset value Vpd by the voltage stabilizing module, so as to reduce the difference in closing response caused by the difference in LED opening voltage.

[0065] Figure 4 The adaptive lamp point opening voltage stabilization is realized by the method of the present application, and the port voltage is rapidly set to a same preset value Vpd after the port is closed, so as to reduce the difference in closing response caused by the difference in LED opening voltage. Figure 4 It can be seen that, before opening, by setting different pre-opening voltage values for each lamp point, the dynamic response before opening is ensured to be consistent, so that the low-gray display consistency can be improved, and the low-gray display problems such as low-gray mottling can be solved; after the port is closed, by rapidly pulling down the port voltage to a same voltage, the difference in closing response caused by the difference in LED opening voltage can be reduced.

[0066] Figure 5 Fig. 1 is a schematic diagram of a port voltage stabilizing system for an LED display screen according to an embodiment of the present application. As shown in the figure, based on the same inventive concept, the present application also discloses a port voltage stabilizing system for an LED display screen, which comprises: Figure 5 Fig. 1 is a schematic diagram of a port voltage stabilizing system for an LED display screen according to an embodiment of the present application. As shown in the figure, based on the same inventive concept, the present application also discloses a port voltage stabilizing system for an LED display screen, which comprises:

[0067] a sampling module 10 for detecting the lamp point opening voltage of the output port of each lamp point;

[0068] a setting module 20 for setting the pre-opening voltage fine-tuning gear of each lamp point according to the lamp point opening voltage;

[0069] a voltage stabilizing module 30 for, during normal display, adjusting the voltage stabilizing voltage of the output port of each lamp point according to the pre-opening voltage fine-tuning gear before each row scanning opening, and setting the port voltage of the output port of all lamp points to a same preset voltage value after the output port is closed.

[0070] Specifically, in an embodiment of the present application, the setting module comprises:

[0071] a setting unit for setting the detection voltage Vf_test, the lower limit of the detection voltage Vf_test-a and the upper limit of the detection voltage Vf_test+a;

[0072] a judging unit for judging whether the lamp point opening voltage is greater than the lower limit of the detection voltage and less than the upper limit of the detection voltage, and if so, setting the pre-opening voltage fine-tuning gear of the lamp point according to the difference between the detection voltage and the lamp point opening voltage.

[0073] In the port voltage stabilizing system for the LED display screen, if the lamp point opening voltage is less than the lower limit of the detection voltage or greater than the upper limit of the detection voltage, the detection voltage is adjusted to a lower gear or a higher gear, then the next lamp point is set, and the scanning is repeated until the opening voltage stabilizing gear setting of all lamp points is completed.

[0074] In the port voltage stabilizing system for the LED display screen, the setting module further comprises a lamp point abnormality detection unit, which is used for judging whether the lamp point opening voltage is greater than the highest detection voltage or less than the lowest detection voltage, and if yes, the lamp point is set as an abnormal lamp point.

[0075] The functions of each functional module in the device embodiment can be specifically realized according to the method in the method embodiment, and the specific implementation process can be referred to the related description of the method embodiment, which will not be repeated here.

[0076] It should be noted that, in the above description of various modules, the division into these modules is for the purpose of clarity. However, in actual implementation, the boundaries of various modules can be blurred. For example, any or all functional modules herein can share various hardware and / or software elements. For another example, any and / or all functional modules herein can be implemented in whole or in part by a common processor executing software instructions. In addition, various software sub-modules executed by one or more processors can be shared among various software modules. Accordingly, the scope of the present application is not limited by the mandatory boundaries of various hardware and / or software elements, unless explicitly required.

[0077] The embodiment also discloses an LED display screen driving device, comprising a processor and a memory, the memory stores a computer program, and the computer program is executed by the processor to realize the steps of the method as described above, and the specific implementation process can be referred to the related description of the method embodiment, which will not be repeated here.

[0078] The embodiment also discloses a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the steps of the method as described above, and the specific implementation process can be referred to the related description of the method embodiment, which will not be repeated here.

[0079] Those skilled in the art can understand that, all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiments. The storage medium can be a magnetic disc, an optical disc, a read-only memory (ROM) or a random access memory (RAM) and the like.

[0080] While embodiments of the application have been described in connection with the preferred embodiments of the various figures, those of ordinary skill in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the application, and that such modifications and changes fall within the scope of the appended claims.

Claims

1. A port voltage stabilizing method for an LED display screen, characterized in that, The method comprises the following steps: Step S1, detecting the lamp point start voltage of the output port of each lamp point; Step S2, setting the pre-start voltage fine adjustment level of each lamp point according to the lamp point start voltage; Step S3, during normal display, adjusting the voltage of the output port of each lamp point according to the pre-start voltage fine adjustment level before scanning start of each row; and Step S4, after the output port is closed, setting the port voltage of the output port of all lamp points to the same preset voltage value at the same time; Step S2 comprises: Step S21, setting the detection voltage Vf_test, the lower limit of the detection voltage Vf_test-a and the upper limit of the detection voltage Vf_test+a; Step S22, judging whether the lamp point start voltage is greater than the lower limit of the detection voltage and less than the upper limit of the detection voltage, if yes, setting the pre-start voltage fine adjustment level of the lamp point according to the difference between the detection voltage and the lamp point start voltage.

2. The port voltage stabilizing method for an LED display screen according to claim 1, wherein, If the lamp point start voltage is less than the lower limit of the detection voltage or greater than the upper limit of the detection voltage, after adjusting the detection voltage to the lower limit or the upper limit, the next lamp point is set, and after scanning of all lamp points is completed, the scanning is repeated until the pre-start voltage fine adjustment level setting of all lamp points is completed.

3. The port voltage stabilizing method for an LED display screen according to claim 1, wherein, Further comprising judging whether the lamp point start voltage is greater than the highest detection voltage or less than the lowest detection voltage, if yes, setting the lamp point as an abnormal lamp point.

4. A port voltage stabilizing system for an LED display screen, characterized by, Comprise: A sampling module for detecting the lamp point start voltage of the output port of each lamp point; A setting module for setting the pre-start voltage fine adjustment level of each lamp point according to the lamp point start voltage; A voltage stabilizing module for adjusting the voltage of the output port of each lamp point according to the pre-start voltage fine adjustment level before scanning start of each row during normal display, and setting the port voltage of the output port of all lamp points to the same preset voltage value at the same time after the output port is closed; The setting module comprises: A setting unit for setting the detection voltage Vf_test, the lower limit of the detection voltage Vf_test-a and the upper limit of the detection voltage Vf_test+a; A judging unit for judging whether the lamp point start voltage is greater than the lower limit of the detection voltage and less than the upper limit of the detection voltage, if yes, setting the pre-start voltage fine adjustment level of the lamp point according to the difference between the detection voltage and the lamp point start voltage.

5. The port regulation system for LED display screens of claim 4, wherein, If the lamp point start voltage is less than the lower limit of the detection voltage or greater than the upper limit of the detection voltage, after adjusting the detection voltage to the lower limit or the upper limit, the next lamp point is set, and after scanning of all lamp points is completed, the scanning is repeated until the pre-start voltage fine adjustment level setting of all lamp points is completed.

6. The port regulation system for LED display screens of claim 4, wherein, The setting module further comprises a lamp point abnormality detecting unit for judging whether the lamp point start voltage is greater than the highest detection voltage or less than the lowest detection voltage, if yes, setting the lamp point as an abnormal lamp point.

7. An LED display screen driving device, characterized in that, The method comprises the following steps: a processor is included; and a memory connected with the processor; wherein the memory stores instructions executable by the processor, and the instructions are executed by the processor to make the processor execute the port voltage stabilizing method for the LED display screen in any one of claims 1 to 3.

8. A non-transitory computer-readable storage medium, comprising: The non-transitory computer readable storage medium stores computer instructions for making a computer execute the port voltage stabilizing method for the LED display screen in any one of claims 1 to 3.

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