LED display parameters and terminology

LED display parameters and terms:

1. LED brightness

The brightness of a light-emitting diode is generally expressed in luminous intensity (Luminous Intensity), and the unit is candela cd; 1000ucd (microcandela) = 1mcd (millicandela), 1000mcd = 1cd. The light intensity of a single LED for indoor use is generally 500ucd-50mcd, while the light intensity of a single LED for outdoor use should generally be 100mcd-1000mcd, or even more than 1000mcd.

2. LED pixel module

LEDs are arranged in a matrix or segments and prefabricated into standard-sized modules. Commonly used indoor display screens are 8*8 pixel modules and 8-character 7-segment digital modules. Outdoor display pixel modules have specifications such as 4*4, 8*8, and 8*16 pixels. The pixel modules used in outdoor display screens are also called cluster modules because each pixel is composed of more than two LED tube bundles.

3. Pixel and pixel diameter

Each LED light-emitting unit (dot) that can be individually controlled in an LED display is called a pixel (or element). Pixel diameter ∮ refers to the diameter of each pixel, in millimeters.

For indoor display screens, generally one is a single LED with a circular shape. Common diameters of indoor display screen pixels are ∮3.0, ∮3.75, ∮5.0, ∮8.0, etc., among which ∮3.75 and ∮5.0 are the most common.

In outdoor environments, in order to increase brightness and viewing distance, one pixel contains two or more clustered LEDs. Since more than two clustered LEDs are generally not circular, the pixel diameter of an outdoor display is generally expressed by the average distance between two pixels: □10, □11.5, □16, □22, □25.

4. Dot pitch, pixel density and information capacity

The center distance between two pixels of LED display screen is called dot pitch; the number of pixels per unit area is called pixel density; the amount of display content contained in a unit area is called information capacity. These three are essentially describing the same concept: dot pitch reflects pixel density from the distance between two pixels. Dot pitch and pixel density are physical properties of display screen; information capacity is the quantitative unit of information carrying capacity of pixel density.

The smaller the dot pitch, the higher the pixel density, the more information capacity, and the closer the suitable viewing distance.

The larger the dot pitch, the lower the pixel density, the less information capacity, and the longer the suitable viewing distance.

5. Resolution

The number of rows and columns of LED display pixels is called the resolution of the LED display. Resolution is the total number of pixels on the display, which determines the information capacity of a display.

6. LED Panel

An LED display screen is formed by assembling LED pixel modules into a matrix according to the actual required size, and equipped with a dedicated display drive circuit, DC regulated power supply, software, frame and exterior decoration.

7. Grayscale

Grayscale refers to the degree of change in the brightness of a pixel. The grayscale of a primary color generally ranges from 8 to 1024. For example, if the grayscale of each primary color is 256, for a dual-primary color screen, the displayed colors are 256×256=64K, and the screen is also called a 256-color display.

8. Dual primary colors

Most of the current color LED display screens are dual-primary color screens, that is, each pixel has two LED tube cores: one is a red tube core, and the other is a green tube core. When the red tube core is on, the pixel is red, when the green tube core is on, the pixel is green, and when both the red and green tube cores are on at the same time, the pixel is $. Red and green are called primary colors.

9. Full color

The red and green primary colors plus the blue primary color make up the full color. Since the blue tube and pure green tube core that make up the full color are more expensive, there are relatively few full color screens at present.