LED displays in control rooms "blue light hazard"
Because control room users need to watch large screens for long periods of time, “blue light hazard” is a topic that cannot be avoided. It is even more necessary to start from the source of product selection and evaluate the impact of various large-screen display technologies on human eye health. Due to different technical principles, the degree of “blue light hazard” of various large-screen display products is also very different.
As the mainstream display product in the control room, DLP has a leading edge in both display effect and viewing comfort, and its “blue light hazard” is also the smallest. This is because DLP outputs from the LED light source to the screen display, and goes through multiple projection, reflection, transmission and other processes such as light rods, optical micromirrors DMD, mirrors, and optical screens. It can effectively filter high-energy short-wave blue light and display the output to people. The light of the eyes is also the softest and does not hurt the eyes. After more than ten years of accumulation and precipitation, the practical application of DLP in the control room market also proves this.
DLP imaging principle schematic
Around 2012, SMD small-pitch LEDs began to enter the indoor application market one after another. As a “latecomer”, SMD small-pitch LEDs have many advantages in indoor applications, but their “uncomfortable viewing at close range for a long time” has always been one of the main problems that plagued the industry and user applications. The white light in the LED display is formed by mixing the blue LED chip with the three primary colors of the red LED chip and the green LED chip. The spectral energy has a strong blue light band, and the blue light energy is relatively high. In addition, the light-emitting area of the LED chip in the SMD packaging technology is very small, and the light beam is relatively concentrated, so its brightness is quite high, and the blue light damage is also the greatest. Human eyes are directly stimulated by blue light from SMD small-pitch LEDs for a long time, which can easily cause retinopathy.
SMD small-pitch LEDs emit light on the surface, and short-wave blue light will directly hit the human eye
When it comes to the “blue light hazard” of LCD display products, from a technical point of view, it is similar to ordinary electronic terminal products such as ordinary TVs and mobile phones. LCD displays are mostly composed of white LED backlights, and most of the white light is realized by mixing blue LEDs with yellow phosphors. The LED backlight of the LCD display is attenuated by the liquid crystal layer, ColorFilter (color filter) and glass panel, and its degree of “blue light hazard” is between DLP and SMD small-pitch LEDs.
Schematic diagram of LCD imaging principle
In addition, the degree of “blue light hazard” has a lot to do with the choice of brightness and color temperature. The higher the brightness and the higher the color temperature, the greater the blue light damage the human eye accepts.
To sum up, DLP has moderate viewing brightness and soft colors, and its “blue light hazard” is the lowest, which can effectively ensure the comfort and health of human eyes, and is the most ideal control room display product.