Change led display brightness methods

With LED display more widely, LED outdoor advertising display applications that much attention, people are slowly on the inherent characteristics of the cognitive LED display has deepened. The passers-by and drivers who have recently reflected high brightness problems, mainly reflected in the eyes feel uncomfortable for pedestrians, shaking the driver's eyes, the impact of sleep and so on. In order to make the city away from the high brightness LED display problems, LED display manufacturer YUCHIP Electric proposes two solutions: to re-adjust the LED display brightness and color.
First, adjust the brightness
1, change the current through the LED, LED tube to allow continuous ordinary tasks around 20 mA current, in addition to the red LED has a saturation phenomenon, the current is proportional to the rest of the LED brightness is basically flowing.
2, pulse width modulation (PWM), frequency of use of the human eye can feel the change, with the pulse width modulation method to achieve gray scale control, i.e. periodically changing the optical pulse width (i.e. duty cycle), only the repeated cycle of light short enough (ie, refresh frequency is high enough), the human eye is not feel light-emitting pixels trembling. Because the pulse width modulation is more suitable for digital control, it has been made very wide use. Common method is adopted to provide computer LED display. Almost all of the LED screen is adopted to control the pulse width modulation gradation.
Second, the color adjustment
LED display products are based on red, green and blue colors of the LED brightness to adjust the color of the entire screen. We determined according to the selected product of red, green, and blue color which color is brighter than the reference, generally is a low luminance as a luminance ratio of a reference, when the reference has reached a maximum brightness, adjust another species (color) or both (full color). Color display screen is, in most cases with reference to green, red diode operating current adjustment. Generally lower operating current in order to balance the color yellow for the adjustment of the standard, so we must reduce the brightness of the entire display screen. The color display is adjusted to the optimum balance of state, will reduce the brightness of the screen. If the brightness of the display screen in order to achieve the requirements, each color will reach maximum brightness, then lost his balance and color, for example: reddish yellow color of the screen, or greenish.