LED display screen drive control method and drive control circuit

Abstract

The invention relates to the field of LEDs, in particular to an LED display screen drive control method and a drive control circuit. A conventional charge eliminating method (allowing LED lamp bead anode discharging and LED lamp bead cathode charging at the same time) is changed into a charge eliminating step in the technical scheme, and the charge eliminating step includes allowing anode discharging and cathode high resistance, anode and cathode discharging at the same time and anode high resistance and cathode charging; in a row drive time interval of driving each two rows of an LED display screen, the LED display screen is driven to complete the charge eliminating step of parasitic capacitance of scanned rows. By improving the drive mode and the drive circuit, row ghost images and column ghost images can be eliminated, and damage to LED lamp bead due to reverse breakdown voltage is avoided. The circuit is simple in structure, convenient to operate and convenient for actual application.

Description

technical field [0001] The invention relates to the field of LEDs, in particular to a method for driving and controlling an LED display screen and a driving and controlling circuit. Background technique [0002] Such as figure 1 , in the system structure of the existing LED scanning display screen (taking a 3 by 3 LED array as an example), due to the existence of parasitic capacitances C11~C33, CW1~CW3, and CB1~CB3, the LED array will appear abnormal bright spots in the display, These unusual bright spots are also called ghosts. During the process of each row of LED lamp beads being lit sequentially, the adjacent LEDs that should not emit light also appear slightly bright, which is called ghosting. The abnormal light emission of the LEDs located in the row above the normally lit LEDs is called row ghost, and the abnormal light emission of the LEDs in the lower row is called column ghost. [0003] The reason for the line ghost is: when the scan line W1 is driven, the paras...

AI Technical Summary

Problems solved by technology

When the scan line changes from W1 to W2, the voltage of the scan line W2 connected to the anode of the LED lamp bead D23 is close to the high potential of the system power supply VDD. The potential on CB3 remains low, so that the LED lamp bead D23 instantly bears the forward bias voltage greater than the conduction rated voltage and enters the conduction state, and the current passes through the LED lamp bead D23 to charge the parasitic capacitor CB3, causing the light emitting diode D23 to emit light abnormally , forming a column ghost of the LED lamp bead D13 that is normally lit in the previous row

[0005] like figure 2 , image 3 , in order to eliminate row ghosts and column ghosts, discharge and charge functions are added to the row drive circuit and column drive circuit respectively. Since the column drive circuit is charged and the row drive circuit is discharged simultaneously during the driving process, it causes LED The reverse voltage is generated at both ends of the lamp bead, that is, the cathode voltage on the LED lamp bead is greater than the anode voltage, causing the LED lamp bead to be damaged

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