Ordinary users directly add a touch screen to the surface of the LCD screen, and there is an air gap between the touch screen and the LCD screen, forming three reflective surfaces from the outside to the inside: the surface of the touch screen, between the touch screen and the air, and between the air and the touch screen. If no special treatment is carried out, The reflectivity of each reflective surface for external light is approximately 4.2%, and the external light reflected by the three reflective surfaces is 12.6%, 1260 lumens.

If the surface brightness of the screen is 1000 lumens, there are two reflective surfaces from inside out, namely the LCD screen to the air, and the air to the back of the touch screen. After being reflected by two reflective surfaces, the brightness that passes through the touch screen surface is 916 lumens.

The optical binding display screen uses transparent optical adhesive to bond the touch screen or protective glass onto the polarizer on the front surface of the LCD screen. Due to the fact that the refractive index of the optical adhesive glass is almost the same, both are 1.5, thus eliminating two reflective surfaces. At the same time, the outer surface of the touch screen or protective glass is coated with an AR anti reflection layer, resulting in a reflectivity of only 0.4% for the entire external light. Lower reflection loss means higher contrast. Backlight 500 lumens, readable under sunlight; 800 lumens, readable under strong light.