How does LED display water ripple come into being?

LED display and LCD display will have water ripple, which is also known as “Moore pattern”; how to judge, the simplest is to pick up the mobile phone to take photos, you can see a lot of stripes, that is water ripple.
Is the water ripple of full color LED display the same as the scan line?
1. Water ripple: generally presents irregular arc diffusion state!
2. Scan line: horizontal black stripe line, mainly due to the low refresh of the display screen, captured and presented by the camera!
Moire pattern is a manifestation of beat difference principle. When two equal amplitude sine waves with similar frequency are superimposed, the amplitude of the synthesized signal will change according to the difference between the two frequencies.
How does water ripple of full color LED display screen come into being?
1. Two stripes with slightly different spatial frequencies have the same black line position at the left end. Because of the different spacing, the stripes can not be overlapped gradually to the right.
2. The two stripes overlap. Because the black lines overlap on the left, you can see the white line. And the right side gradually dislocation, white line to black line, overlapping results become all black. There are white lines and all black changes, forming a moire.
3. The pixel distribution density of full-color display screen is just between the intervals that can be distinguished by CCD. The inevitable digital camera will still interpret some recognizable results, but it will also add the unrecognizable gray-scale area. The sum of the two will form regular lines, which is reflected in the periodic ripple in vision.