CN113487989B - LED display module detection method and detection system thereof - Google Patents

Abstract

The invention relates to a method for detecting an LED display module, which comprises the following steps: and controlling the LED display module to display a test picture, observing whether the fault phenomenon of the caterpillar occurs or not by adjusting the blanking voltage VH and the blanking time of each row of LEDs in the row driving ICs, and considering that the LED display module has the fault if the fault phenomenon of the caterpillar occurs. The method can fully expose the fault phenomenon of the caterpillar, further screen out defective products, and can avoid the missing detection and the missing judgment of the defective LED display module.

Description

A kind of LED display module detection method and detection system

technical field

The invention belongs to the technical field of LED display module detection, and in particular relates to a detection method of an LED display module and a detection system thereof.

Background technique

At present, the use of LED display screen is more and more extensive, and the product use has gradually penetrated from traditional outdoor display to indoor commercial display. The dot pitch of LED displays used in commercial display products has also gradually decreased, and has entered the Mini-LED era, and the dot pitch of indoor LED displays is basically below 2mm. With the commercialization of the use of LED displays, people have higher and higher quality requirements for LED displays, and the reduction in dot pitch increases the failure rate of LED displays. How to screen out the faulty LED display modules before assembling them into a large screen is one of the important ways to ensure product quality. It also reduces the post-sale maintenance cost of the screen factory and improves the brand awareness of the screen factory.

Due to the quality of the light-emitting chip and the manufacturing process of the LED display module, the "caterpillar" phenomenon will appear in the LED display module. In the process of indoor use, the problem will be magnified by the customer watching at close range. The traditional LED display module detection method only detects the quality of the module under the 255-level red, green and blue state.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide an LED display module detection method and a detection system thereof, which can expose the problem of defective LED display modules during the manufacturing process of the LED display modules and avoid leakage of defective LED display modules. Leak detection.

In order to solve the above-mentioned technical problem, the LED display module detection method of the present invention is as follows: control the LED display module to display a test image, and adjust the LED blanking voltage VH of each column in the column driver IC to make it Change in the range of 2.0V ~ 3.75V, adjust the LED blanking time of each column in the column driver IC to change in the range of 1000ns ~ 1600ns, and observe whether there is a "caterpillar" fault phenomenon, if there is a "caterpillar" fault phenomenon It is considered that the LED display module is faulty.

The test picture is a black picture.

The test picture is an oblique line picture.

The test picture is a low gray pattern of red, green and blue with a gray value of 20-50.

The range of the LED blanking voltage VH is preferably 2.0V to 3.0V.

The LED blanking time range is preferably 1000ns to 1600ns.

The detection system for realizing the above-mentioned LED display module detection method includes a host computer, a receiving card and a driving circuit; the host computer communicates with the receiving card; the receiving card is connected with the driving circuit.

The host computer is connected with the receiving card through a network cable, and the receiving card is connected with the driving circuit through a connector.

The test picture is stored in the upper computer.

The test picture is stored in the receiving card.

At present, the LED display screen adopts the PWM driving method in the production process. The present invention sets the drive IC register parameters through the host computer software, and uses the blanking function of the PWM drive chip to amplify the "caterpillar" and "low gray, dark and bright" phenomena of the LED display module, so that the "caterpillar" fault phenomenon can be fully resolved. Expose, and then screen out defective products, which can avoid missed detection and missed judgment of defective LED display modules. The host computer is directly connected to the receiving card through a Gigabit network cable, and the host computer upgrades the program and sets the parameters of the receiving card through the network card mode, which saves the sending part and saves resources. The drive circuit is connected to the LED display module by a cable. This connection method improves the flexibility of the use of the drive circuit module. A set of drive circuit modules can be applied to the conventional dot-pitch LED display modules in the current market, which improves production. efficiency and cost savings.

Description of drawings

In order to better illustrate the technical solutions of the embodiments of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

FIG. 1 is a structural diagram of an LED display module detection system of the present invention.

Figures 2a and 2b are diagrams showing the production mechanism of "caterpillars".

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, the drawings only show some but not all structures related to the present invention.

In the description of the present invention, unless otherwise expressly specified and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or a fixed connection. It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be specifically understood in specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may include the first and second features in direct contact, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below", and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the level of the first feature is smaller than the second feature.

In the description of this embodiment, the terms "up", "down", "left", "right" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for convenience of description and simplified operations. It is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. In addition, the terms "first" and "second" are only used for distinction in description, and have no special meaning.

The LED display module detection method of the present invention is as follows:

Control the LED display module to display the test screen, and adjust the LED blanking voltage VH of each column in the column driver IC to change within the range of 2.0V to 3.75V under the condition that the ambient brightness is below 10 lux, and adjust each column in the column driver IC. Set the LED blanking time to vary within the range of 1000ns to 1600ns, and observe whether there is a "caterpillar" fault. If there is a "caterpillar" fault, it is considered that the LED display module is faulty; the test screen is black Field picture, oblique line picture or red, green, blue low gray pattern, etc.; the gray value of red, green, blue low gray pattern is 20-50.

The LED display module includes LED lamp beads arranged in a matrix, as shown in Figure 2a, when the middle LED lamp bead L1 is short _- circuited, the LED lamp beads in the same column will form a path as shown in Figure 2b when scanning to the row , if the voltage difference between point A and point B is greater than the on-voltage VF of the LED lamp bead, that is, VLED-VH>VF, a row of always-on caterpillars will be formed, making the LED display module expose the caterpillar phenomenon; among them VLED is the column drive voltage, and VH is the blanking voltage.

In the industry, the display problems such as the first line dark and bright, sub-bright and coupling are usually solved by setting the blanking voltage and blanking time. The inventor of the present invention accidentally found in the long-term design and debugging that the caterpillar phenomenon can be exposed by adjusting the blanking voltage and the blanking time under a suitable test picture and test environment. However, the unreasonable setting of blanking voltage and blanking time will lead to excessive reverse voltage of the light-emitting chip, which will affect the life of the light-emitting chip. Through a large number of experimental verifications, the inventor has determined that the test screen is displayed on the LED display module, and the ambient brightness is below 10 lux. , Under the condition that the blanking voltage VH of each column of LEDs is in the range of 2.0V to 3.75V, and the blanking time is in the range of 1000ns to 1600ns, it can not only ensure that the caterpillar problem is exposed but not affect the life of the light-emitting chip.

The experimental results corresponding to different blanking parameters, test images and test environments are shown in Table 1.

Table 1

The above detection method can be realized by the following LED display module detection system.

As shown in Figure 1, the LED display module detection system of the present invention includes a host computer, a receiving card and a drive circuit; the host computer is connected to the receiving card through a network cable, and communicates with the receiving card through a Gigabit network; the receiving card is connected to the receiving card. The plug-in method is connected with the driving circuit, which can facilitate the removal and insertion of the receiving card and the replacement; the LED display module is connected with the driving circuit through a cable.

The receiving card program can be upgraded through the host computer and the test screen configuration file to be displayed can be loaded into the receiving card, and then the LED display module can be lit through the driver IC in the driver circuit to display black, slash, red, green, blue and low gray patterns. You can also store the test screen to be displayed directly in the receiving card, and turn on the LED display module through the driver IC. Under the condition of ambient brightness below 10 lux, it will display black field, slash, red, green, blue and low gray. Pattern and other test pictures; adjust the blanking voltage of each column of LEDs in the driver IC register to change within the range of 2.0V to 3.75V through the host computer, and adjust the blanking time to change within the range of 1000ns to 1600ns; If the "bug" failure phenomenon occurs, it is considered that the LED display module is faulty.

Claims (7)

1. A detection method of an LED display module is characterized by comprising the following steps: controlling an LED display module to display a test picture, adjusting blanking voltage VH of each row of LEDs in a row driving IC to change within the range of 2.0V-3.75V under the condition that the ambient brightness is below 10 lux, adjusting blanking time of each row of LEDs in the row driving IC to change within the range of 1000 ns-1600 ns, observing whether the fault phenomenon of 'caterpillar' occurs, and if the fault phenomenon of 'caterpillar' occurs, determining that the LED display module has a fault; the test picture is a black field picture, a diagonal picture or a red, green and blue low-gray pattern with the gray value of 20-50.

2. The method as claimed in claim 1, wherein the LED blanking voltage VH is in the range of 2.0V to 3.0V.

3. The method for detecting the LED display module according to claim 1, wherein the blanking time of the LED is between 1000ns and 1600 ns.

4. A detection system for realizing the detection method of the LED display module set according to claim 1 is characterized by comprising an upper computer, a receiving card and a driving circuit; the upper computer is communicated with the receiving card; the receiving card is connected with the driving circuit.

5. The LED display module detection system of claim 4, wherein the host computer is connected to the receiving card through a network cable, and the receiving card is connected to the driving circuit through a connector.

6. The LED display module detection system of claim 4, wherein the test frame is stored in an upper computer.

7. The LED display module inspection system of claim 4, wherein the test frame is stored in a receiving card.

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