Since the launch of Apple’s iPad, the tablet computer market has been very hot. Domestic manufacturers have also launched their own products, but in order to control costs, many domestic tablet manufacturers use low-end screens in their products. The most obvious problem with these screens is that when they are turned off or in a darker picture, you will see obvious grids on the screen. The shape of these grids is like the word "I", so everyone named these screens "I". screen".

How is the I-shaped screen formed?

The sensing element in the capacitive touch screen is made of the same material The carrier materials of the entire flat panel are different. Although they are the same transparent color, they are two conductors with different transmission rates for light. When light passes through the interface of two different media, if the incident angle is greater than a certain angle (Related to the speed of light in the medium) refraction occurs. When a relatively parallel external light source is incident at a large angle, it passes through the capacitive touch screen and is reflected by the TFT screen and passes through the touch screen again. Due to the effect of refraction in this process, there will be areas where no reflected light exists in the cross section of the returning light beam, which creates a visual grid. The key to the emergence of this kind of grid is that the external light is relatively strong and occurs when it is greater than a certain incident angle. The internal TFT screen is very close to the external screen, although the light it emits (the light that passes through) will also It is emitted from the external screen, but the theoretical incident angle is very close to vertical, so there will be no refraction, so it will have no impact on the internal display.

Therefore, although the I-shaped screen looks more obvious when it is turned off or the screen is dark, it is generally difficult to detect when the screen is in normal use. As long as you are not too picky, it basically does not affect use. Apple's iPad uses an IPS hard screen, and the manufacturing process is different, so it won't have the problem of an I-shaped screen, but its price is also a level higher than these I-shaped screens.