Nowadays, many LCD display products use LED backlights, which are mainly divided into two types: straight down and side in. Below, Ruxin will introduce the differences between these two types:

Straight down LED backlight
1. The straight down LED backlight process is simple and does not require a light guide plate. The LED array is placed at the bottom of the lightbox, and the light emitted from the LED is reflected through the bottom and side, and then evenly emitted through the diffusion plate and optical module on the surface.
2. The thickness of the straight down LED backlight source is determined by the distance between the bottom of the lightbox and the scattering plate. Generally, the thicker the thickness, the better the uniformity of the LED backlight source's light. In the case of a thin LED backlight source, color and brightness uniformity become the technical key of a straight down LED backlight source.
3. Most straight down LED backlight sources use edge emitting LEDs, but large angle edge emitting LEDs can easily cause dark spots due to low intermediate light intensity, which affects the uniformity of the LED backlight source.

Side entry LED backlight
1. The side entry backlight module sets the point light source on the side of the specially designed light guide plate as the LED backlight source, using fewer LEDs.
2. When the side entry LED backlight source is placed on the side of the light guide plate and the LED is limited by the number and brightness, it is still necessary to evenly distribute the light on the entire plane. This will result in a situation where the larger the panel area, the more limited the use of the light source.
3. As the LED backlight source is placed on the side of the product, only a light guide plate needs to be added at the back, so the appearance thickness of the LCD product can be very thin.
Comparison of advantages and disadvantages
1. The side entry type saves more LED beads than the straight down type. Obviously, only the LED beads with one edge circle are much more efficient than the full screen of the straight down type, so the overall energy consumption is lower than that of the straight down type;
2. The side entry type can be made thinner because it is a light source placed on the side, so there is no need to consider some issues caused by being too close to the panel.
3. The side entry type relies too much on the quality of the light guide plate, and the emitted light is not as uniform as the straight down type, which is prone to light leakage problems.
4. Firstly, the straight down backlight is evenly distributed by multiple LED lights behind the panel, allowing the backlight to be evenly transmitted to the entire screen, making the image details more delicate and realistic.
5. The straight down backlight source can achieve matrix style area control of light, and the LED lights in each area can be freely controlled for brightness and dimming. When displaying black, simply turn off the light in the corresponding LED area to display a very perfect black color. Therefore, it can display better color and contrast effects.
Through the above comparison, it can be found that the straight down LED backlight source and the side in LED backlight source each have their own advantages. You can choose different types of LED backlight sources according to your own needs.
Ruxin Gaoliang is a national high-tech enterprise that integrates research and development, design, production, and sales. The main products include four categories: small and medium-sized LCD screens, high brightness LCD screens, strip LCD screens, and transparent LCD screens. The application industries include outdoor advertising machines, rail transit, handheld terminals, smart homes, medical equipment, instrumentation, digital projectors, supermarket displays, and other industries.
The company established a branch in Hubei in 2018, with a factory area of 20000 square meters. It has a professional technical research and development team and an excellent management team, which can independently design and develop high brightness backlight structures and optical structure combinations. The company has first-class domestic production equipment such as cutting machines, high brightness production lines, COG bonding machines, FOG bonding machines, etc. The monthly production capacity is small size 1KK, high brightness 30K, and bar screen 5k.