Why do we need to use an LED screen instead of a traditional projection? Are there some disadvantages of projection technology?

Nowadays, most of the movie theaters still adopt the technology of projection. It means the image is projected on the white curtain by the projector. As the small pitch LED screen is born, it begins to be used for the indoor fields, and gradually replace the projection technology. Therefore, the potential market space for small-pitch LED displays is huge.
While the high brightness is one of the outstanding features of the LED screen, it generally adopts the principle of self-illumination, each pixel emits light independently, so the display effect is the same in different positions of the screen. What’s more, the LED screen adopts all black screen background, which has better contrast than traditional projection technology.

Normally, most of the playback equipment used in traditional theaters is projection technology. Because the projection system uses the principle of reflection imaging, the distance between the projected light and the center of the screen is different, and the position of the three primary color light sources in the projection tube is different. This feature causes the projected picture is easy to exist with a small amount of pixel defocus and colorful edge. In addition, the movie screen uses a white curtain, which will reduce the contrast of the picture.
Pros and cons of LED projectors
Pros: The biggest advantage of LED projectors is their lamp life and low heat output. LEDs last at least 10 times longer than traditional projector lamps. Many LED projectors can run for 10,000 hours or more. Since the lamp lasts the life of the projector, you don’t have to worry about buying new lamps.

Because LED’s are so small and only need to semi-conduct, they operate at much lower temperatures. This means that they don’t need as much airflow, allowing them to be quieter and more compact.

Much faster start up and shut down times as no warm up or cool down is needed. LED projectors are also much quieter than projectors that use traditional lamps.

Cons: The biggest disadvantage of LED projectors is their brightness. Most LED projectors max out at around 3,000 - 3,500 lumens.
LED is not a display technology. Instead it’s a reference to the light source used.