When the axial directions of the upper and lower polarizers are the same and no voltage is applied, the irradiated light is blocked, which is "black" at this time; When there is an applied voltage, the irradiated light energy passes through, and it is white at this time. This kind of LCD is called normally black LCD.
Extended data:
LCD liquid crystal display is widely used in industrial control, especially in the display of man-machine of some machines, panels of complex control equipment and medical instruments.
I often use LCDs with resolutions of 320x240, 640x480, 800x600, 1024x768 and above in industrial control and instrumentation.
Commonly used sizes are 3.9 ",4.0", 5.0 ",5.5", 5.6 ",5.7", 6.0 ",6.5", 7.3 ",7.5", 10.0 ",10.4" and 65434. Colors are black and white, false color, 5 12 color, 16 color, 24-bit color and so on.
Some users often confuse resolution with point distance. Actually, they are two completely different concepts. Resolution is usually expressed by the product of horizontal pixels and vertical pixels. The more pixels, the higher the resolution.
So the resolution is usually measured by the number of pixels, such as the resolution of 640×480, and the number of pixels is 307200.
Note: 640 is the number of horizontal pixels and 480 is the number of vertical pixels.
Because in the graphic environment, high resolution can effectively reduce the screen image, therefore, in the case of the same screen size, its resolution cannot exceed its maximum reasonable limit, otherwise, it will lose its meaning.