What's difference between led screen viewing angle and reading angle?

The operational lifetime of the led display is determined by the lifetime of the LEDs. LED Manufacturers estimate the LED lifetime to be 100,000 hours under certain operating conditions. led screen end of lifetimes is when the frontal brightness has decreased to 50% of original brightness.

Three primary factors determine LED lifetime: Manufacturing process of the LED Driving (powering) method of the LED Temperatures present at the LED die during operation.

LED thermal management is vitally important to maintaining LED lifetime. Increasing the power through an LED increases brightness but reduces its lifetime due to increased heat generation. Increased exposure to higher temperature also shortens the lifetime. LED thermal management can only be done through the LED lead frame by conducting the heat to a Printed Circuit Board (PCB) and by allowing airflow to cool the LED lead frame.

led screen components must be designed to handle a wide rang of outdoor environmental factors, such as temperature and humidity. All components must be coated to protect from possible corrosion.

The viewing angle defines the area that will provide optimum viewing of the led screen. This angle is determined by the points off-center, both horizontal and vertical, where the measured light intensity is fifty percent of that measured directly in front of the led screen. The maximum viewing angle is defined as the vertical and horizontal points where the displayed information can no longer be interpreted correctly by the viewer.

In other words, viewing angle refers to the angle at which brightness or contrast drops below 50% of the maximum. led screen are available with different viewing angles. Depending on your audience, you may prefer a display with a narrow viewing cone (sometimes more appropriate for drive-by traffic) or displays with super-wide (140 degree horizontal) viewing (usually best for sports venues).

In summary: Viewing angle is the angle at which the led screen’s brightness is halved. Reading angle is the angle at which a typical person can adequately read an electronic message center. The reading angle is typically more than the viewing angle. http://www.esdled.com