Why are the LCD screens black? Instead of white or other colors?
The LCD screen is divided into two types, normally white and black, and often black includes LG's IPS screen, Samsung's SPVA screen, and Taiwan's AUO MVA screen, etc. Their basic principle is this:
The backlight is a point light source that emits light in all directions.
Through the light guide plate, the backlight becomes even
By controlling the magnitude of the voltage, it is possible to control the angle of liquid crystal twisting, that is, to control the brightness obtained through this liquid crystal.
If you can understand the above principles, the conclusions behind are easy to understand.
Why do we see black and white LCDs that are mostly black? Mainly due to cost, necessity and longevity reasons.
No need to use color, you can save the cost of filter glass
No need to combine three primary colors into one, the same panel, the pixel is three times the original
Only black and white colors are used instead of black-and-white uniform grayscale, which can reduce the cost of the control circuit (only 0 and 1 a ==)
Voltage control can also be very arbitrary, do not need to be very dark or very white, almost can, the accuracy of the circuit design requires a lot less
Fewer circuits and components, higher life and stability, and lower cost
For products that do not have a backlight source and use ambient light as a light source, the backlight is also omitted, and the power and energy consumption of the backlight are also omitted.
For the question of why not use the background black to display white, the answer is that the commonly used display panel of glass and plastic is transparent, and the cost of blackening glass and plastic will increase.
Supplement: When the LCD is off, it is also black, because most of the display methods used by LCDs are based on the principle described above. When the power is off, the liquid crystal does not rotate, the backlight is not turned on, the upper and lower polarizers are perpendicular to each other, and all light is blocked. So it is black.
The LCD screen is divided into two types, normally white and black, and often black includes LG's IPS screen, Samsung's SPVA screen, and Taiwan's AUO MVA screen, etc. Their basic principle is this:
The backlight is a point light source that emits light in all directions.
Through the light guide plate, the backlight becomes even
By controlling the magnitude of the voltage, it is possible to control the angle of liquid crystal twisting, that is, to control the brightness obtained through this liquid crystal.
If you can understand the above principles, the conclusions behind are easy to understand.
Why do we see black and white LCDs that are mostly black? Mainly due to cost, necessity and longevity reasons.
No need to use color, you can save the cost of filter glass
No need to combine three primary colors into one, the same panel, the pixel is three times the original
Only black and white colors are used instead of black-and-white uniform grayscale, which can reduce the cost of the control circuit (only 0 and 1 a ==)
Voltage control can also be very arbitrary, do not need to be very dark or very white, almost can, the accuracy of the circuit design requires a lot less
Fewer circuits and components, higher life and stability, and lower cost
For products that do not have a backlight source and use ambient light as a light source, the backlight is also omitted, and the power and energy consumption of the backlight are also omitted.
For the question of why not use the background black to display white, the answer is that the commonly used display panel of glass and plastic is transparent, and the cost of blackening glass and plastic will increase.
Supplement: When the LCD is off, it is also black, because most of the display methods used by LCDs are based on the principle described above. When the power is off, the liquid crystal does not rotate, the backlight is not turned on, the upper and lower polarizers are perpendicular to each other, and all light is blocked. So it is black.