introduction to the gray level of led display

Introduction to the gray level of LED display

 

 

 

 

 

LED display gray scale is one of the important parameters of LED display, LED display gray scale is the color level or gray scale of LED, refers to the brightness of the LED display brightness, LED display gray level refers to the brightness level of the LED display from the darkest to the brightest brightness can be distinguished between the brightness.

 

The gray level of the LED display determines the color of the LED display, generally speaking, the higher the gray scale, the richer the color of the display, the more delicate the picture, and the easier it is to express rich details.

 

LED display gray scale, 8 levels, 16 levels, 32 levels, 64 levels, 128 levels, 256 levels, 1024 levels, etc., domestic LED display mainly uses 8-bit processing system, international brand LED display mainly uses 10-bit processing system.

 

1. The 8-bit processing system, that is, 256 (2 to the 8th power) level of grayscale, is simply understood as a total of 256 brightness changes from black to white.

2. The 10-bit processing system, that is, 1024 (2 to the 10th power) level of grayscale, is simply understood as a total of 1024 brightness changes from black to white.

3. The 12-bit processing system, that is, the 4096 (2 to the 12th power) level of grayscale, is simply understood as a total of 4096 brightness changes from black to white.

4. The 14-bit processing system, that is, 16384 (2 to the 14th power) level of grayscale, is simply understood as a total of 16384 brightness changes from black to white.

Although grayscale is the determining factor in determining the number of colors, it does not mean that the larger the limit, the better, because the resolution of the human eye is limited, and the increase in the number of bits processed by the system will involve changes in various aspects of the system, such as video processing, storage, transmission, and scanning, and the cost has increased dramatically, and the cost performance has decreased, generally speaking, civilian or commercial products can use 8-bit systems, and broadcast products can use 10-bit systems.

 

There are two ways to control the grayscale of LEDs:

 

One is to change the flow current,

 

The other is to adjust the pulse width.

 

Change the current flowing through the LED. Generally speaking, LED tubes allow continuous working current around 20 milliamps. Except for the saturated red LEDs, the gray scale of other LEDs is basically proportional to the flowing current.

 

The visual inertia of the human eye and the adjustment of pulse width are used to achieve grayscale control, that is, the periodic change of optical pulse width (i.e., space ratio). As long as the repetitive illumination cycle is short enough (i.e., the refresh rate is high enough), the human eye will not perceive the glowing pixels jittering. Since pulse width adjustment is more suitable for digital control, almost all LED screens use pulse width adjustment to control the gray level. The LED control system usually consists of a main control box, a scanning board, and a display device.