Those who are familiar with it know that there are two ways to adjust the brightness of a full-color LED display: automatic adjustment and manual adjustment. Among them, automatic adjustment is an intelligent adjustment of brightness according to the environment brightness, and manual adjustment is realized by software. Then let's see if it is useful to adjust the brightness of the display with software?
The current software adjusts the brightness, generally 256-level adjustable way. In fact, the software is just an operation interface, and the final change is the PWM duty cycle of the LED display driver through the operation of the software, and the brightness change is realized.
Two methods to control the brightness of the LED display:
One is to change the current flowing through the LED display. Generally, the LED tube allows continuous working current around 20ma. Except for the saturation of the red LED, the brightness of other LEDs is basically proportional to the current flowing; the other method is Using the visual inertia of the human eye, the pulse width modulation method is used to achieve grayscale control, that is, the light pulse width (that is, the duty cycle) is periodically changed. As long as the refresh frequency is high enough, the human eye cannot feel the light-emitting pixels jitter . Because pulse width modulation is more suitable for digital control, today when microcomputers are commonly used to provide LED display content, almost all LED displays use pulse width modulation to control gray levels.
At present, the brightness of the outdoor full-color LED display must be above 1500cd/m2 to ensure the normal operation of the display. Otherwise, the displayed image will not be clear because the brightness is too low. However, the brightness of many outdoor LED displays exceeds 5000cd/m2, and the playback effect is good during the day. However, such high brightness at night will cause serious light pollution and cause trouble to nearby residents.
Therefore, it is very necessary to determine the brightness of the LED display. Adjusting the brightness through software is a necessary method, and it is also a common practice in the industry, which is considered an effective method. Generally, after the completion of the display screen project, the manufacturers will have special training for the software, the purpose is to help customers get started with the management operation as soon as possible.
