What is the difference between side-emitting and direct-emitting SMD LEDs
The side-emitting patch led backlight is a backlight made of a linear or point-shaped light source arranged on the side of a specially designed light guide plate. The direct backlight process is relatively simple and does not require a light guide plate. The light source (LED chip array) and PCB are placed at the bottom of the backlight. After the light is emitted from the LED, it passes through the reflector at the bottom, and then passes through the diffuser on the surface to increase the brightness. The film is ejected evenly.
The brightness of the side-emitting LED lamp beads is relatively low, generally within 3000lm with 595*595 specifications;
It can be applied to some occasions where the ceiling is low.
It is thinner and the thickness is within 15mm.
The surface uniformity is poor, and the brightness uniformity is up to 0.85. If the treatment is not good, there will be more obvious bright edges around.
The cleanliness of the workshop is high, the process control is not good, and the yield is low (mainly dust causes the bright spots in the light guide plate).
The finished side-emitting panel light uses the light guide plate technology to design the light guide plate dots according to the arrangement of the LED lamp bead and the light-emitting angle of the lamp bead, so that the light passes through the light guide plate to achieve the effect of uniform brightness.
What is the difference between side-emitting and direct-emitting SMD LEDs?
The back light panel light is designed to use the LED light angle to make a reasonable LED spacing, and cooperate with the diffuser and the height of the lamp to achieve the ideal light mixing effect.
Emphasis on high brightness, 595*595 specifications can reach 4000lm, high luminous efficiency product, replace the traditional grille lamp panel.
Thicker, usually more than 45mm in thickness.
The light output is relatively uniform, and the brightness uniformity can reach above 0.9.
The process requirements are relatively simple.
When the side-emitting SMD LED backlight is applied to medium and large-sized LCDs, the weight and cost of the light guide plate will increase with the increase in size, and the brightness and uniformity of the light emission are not ideal. At the same time, the side-emitting SMD LED backlight LCD TV is because The use of light guide plates cannot realize the dynamic regional control of the LCD TV, but can only realize simple one-dimensional dimming, while the direct-lit LED backlight performs better and can realize the regional dynamic control of the LCD TV. The edge-lit backlight can be made very thin, but the light utilization rate of the backlight source is smaller, and the thinner the utilization rate is smaller. Its technical core is the design and production of the light guide plate. At present, there are mainly two types of printing and injection molding. In the form of light guide plate, others such as injection molding and printing, laser dotting, and corrosion account for a small proportion, which is not suitable for the principle of mass production. The advantages of direct backlight technology are high brightness, good light viewing angle, high light utilization efficiency, and simple structure.
Reserve a certain space between the diffuser and the LED light source to improve brightness uniformity. Therefore, the direct-lit backlight also increases the thickness, weight, and power consumption of the module at the same time. Therefore, the number of light sources, luminous brightness and power consumption are all larger than those of the side. Light-type backlight.
