CN104821144A - LED display defective pixel automatic detecting device and detecting method thereof - Google Patents

Abstract

The invention discloses an automatic detection device for dead pixels of an LED display screen, comprising: a single-chip microcomputer, a shift register, a decoder and a triode; the I/O port of the single-chip microcomputer is connected to the control end of the shift register; Each output end is respectively connected to the cathode end of each row of the LED dot matrix; the anode end of each column of the LED dot matrix is connected in series with the triode after a resistor; each triode is connected with a common base amplifier circuit; each triode emitter is connected to the transistor Each input end of the decoder; the output end of the decoder is connected to the I/O port of the single-chip microcomputer. Through the above method, the present invention can quickly and accurately detect dead pixels, which is suitable for the production process of LED display screens and also suitable for on-site or remote online detection of installed LED display screens. It has a wide range of applications and greatly improves the detection efficiency. , The structure of the device is simple and reliable.

Description

A kind of LED display screen dead point automatic detection device and detection method thereof

technical field

The invention relates to the field of LED screens, in particular to an automatic detection device for dead pixels of an LED display screen.

Background technique

In recent years, LED display screens have developed quite rapidly. Quite a few advertisers use LED display screens to push advertisements. However, there are almost no products involving LED dot matrix dead pixel scanning technology. The traditional detection method is to light up all LED screens. , and then visually detect whether there are dead pixels or not. This method is quite inconvenient. For some outdoor high-altitude advertising screens, this method is neither reliable nor safe.

The published patent for automatic detection of dead pixels on LED screens is too redundant to be practical due to its complicated design. The most important thing is that the existing new LED has a protection design. After burning, the LED part can be equivalent to a resistor to protect other LEDs. The previous method of detecting current changes can no longer automatically detect dead pixels.

Contents of the invention

The technical problem mainly solved by the present invention is to provide an automatic detection device for dead pixels of LED display screens, which can quickly and accurately detect dead pixels, and is suitable for the production process of LED display screens and for the on-site or remote online of installed LED display screens. Detection has a wide range of applications, greatly improves the detection efficiency, and the device structure is simple and reliable.

In order to solve the above-mentioned technical problems, a technical solution adopted by the present invention is to provide an automatic detection device for dead pixels of LED display screens, including: a single-chip microcomputer, a shift register, a decoder and a triode; the I/O port of the single-chip microcomputer is connected to a shift The control end of the bit register; each output end of the shift register is connected to each row of cathode terminals of the LED dot matrix respectively; each column anode end of the LED dot matrix is connected in series with the transistor after a resistor is connected; each transistor is connected with a common base The pole amplifier circuit is connected; each triode emitter is connected with each input terminal of the decoder; the output terminal of the decoder is connected with the I/O port of the single-chip microcomputer.

Preferably, the single-chip microcomputer is connected with a minimum system; the shift register is a 74Hc595 shift register.

A test method for an automatic detection device for dead pixels of an LED display screen. The control center sends a detection command to a single-chip microcomputer through a communication network, and the single-chip microcomputer controls a shift register to send a high level to the cathode terminal of the LED dot matrix display. During the period of sending the high level, The decoder detects the anode terminal voltage of each row. If the anode terminal detects a high level, then that point is a dead point. The single-chip microcomputer records the position of the bad point and sends the bad point information to the control center.

The beneficial effects of the present invention are: the present invention can quickly and accurately detect the dead pixels of the LED display screen, and can detect on-site or remotely.

Description of drawings

Figure 1 is a schematic diagram of a simulation circuit of an automatic detection device for LED display screen failures in the present invention;

Fig. 2 is a schematic flow chart of a detection method of an automatic detection device for dead pixels of an LED display shown;

The marks of each component in the accompanying drawings are as follows: 1. Single-chip microcomputer; 2. Shift register; 3. Decoder; 4. Transistor; 5. LED dot matrix.

Detailed ways

The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so as to define the protection scope of the present invention more clearly.

Please refer to Fig. 1 and Fig. 2, the embodiment of the present invention comprises:

An automatic detection device for dead pixels of an LED display, comprising: a control center, a single-chip microcomputer 1, a shift register 2, a decoder 3 and a triode 4, and the shift register 2 is a 74Hc595 shift register; the control center remotely controls the single-chip microcomputer 1, and Carry out data transmission with single-chip microcomputer 1; Described single-chip microcomputer I/O port connects the control end of shift register 2; Each output end of described shift register 2 connects each row cathode end of LED dot matrix 5 respectively; LED dot matrix 5 Each row of anode ends is connected to the triode 4 after a resistor is connected in series; each triode 4 is connected with a common base amplifier circuit; each triode 4 emitter is connected to each input terminal of the decoder 3; the decoder 3 The output terminal is connected to the I/O port of the microcontroller 1.

As shown in Figure 1, when detecting the LED4×4 dot matrix, the control center sends a detection command to the single-chip microcomputer through the communication network, and the single-chip microcomputer controls the shift register to send a high level to the cathode end of the first column of the LED dot matrix display. During this period, the decoder detects the voltage of the anode terminal of each row in the first column. If the anode terminal detects a high level, such as the first row, it means that the first row of the first column of the LED has a dead pixel, and the single-chip microcomputer records the location of the dead pixel and The dead pixel information is sent to the control center; use the above method to detect the second column of LEDs, the third column of LEDs and the fourth column of LEDs in turn until all LEDs are detected.

The present invention transmits current to LED cathodes one by one, and detects the presence or absence of voltage at its anodes. This method utilizes the diode characteristics of LEDs. If there is voltage at the anode, it means that the LED has been burned or short-circuited. It can simultaneously support on-site detection and Remote online detection to realize fast and accurate positioning detection of bad points.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technologies fields, all of which are equally included in the scope of patent protection of the present invention.

Claims (3)

1. a kind of LED display screen dead point automatic detection device is characterized in that, comprises: control center, single-chip microcomputer, shift register, decoder and triode; Control center carries out data connection with described single-chip microcomputer by network; Described single-chip microcomputer 1 The /O port is connected to the control end of the shift register; each output end of the shift register is respectively connected to the cathode end of each row of the LED dot matrix; the anode end of each column of the LED dot matrix is connected in series with a resistor after being connected to the triode; The triodes are connected with a common base amplifier circuit; the emitter of each triode is connected with each input end of the decoder; the output end of the decoder is connected with the I/O port of the single-chip microcomputer. 2. A device for automatically detecting dead pixels of a LED display screen according to claim 1, characterized in that: said single-chip microcomputer is connected with a minimum system; said shift register is a 74Hc595 shift register. 3. A test method for an automatic detection device for dead pixels of an LED display screen, characterized in that: the control center sends a detection command to the single-chip microcomputer through the communication network, and the single-chip microcomputer controls the shift register to send a high voltage to the cathode terminal of the first column of the LED dot matrix display. Ping, during the period of sending high level, the decoder detects the anode terminal voltage of each row of the first column, if the anode terminal detects a high level, such as N rows, it means that the Nth row of the first column of the LED is a dead pixel, and the single-chip microcomputer Record the position of the dead point and send the bad point information to the control center; if the anode terminal does not detect a high level, then detect the next row of LEDs; use the above method to detect the LED dot matrix in turn until all LED dot matrixes are detected.