Sphere LED screen several characteristics

- Jan 17, 2019 -

  1. The appearance of LED spherical screen is a product in response to people's demand for novelty and oddity.In the early years, if a large flat LED screen appeared in the square, people would be surprised: such a big TV!Now these "big TVS" can no longer satisfy people's curiosity.If one day, there is an outdoor LED spherical screen with a diameter of 5 meters in the square, it will be a very popular product.Therefore, it is an unconventional and popular product.All defects caused by using a flat video source to play on a three-dimensional sphere will be tolerated, just as distorted images taken with a wide-angle lens or fish-eye camera will be accepted.


  2. The playback principle of LED screen: the control system of LED screen (controller + computer) transmits the image source played on the computer screen to the flat LED screen for display.

Almost all the image sources in the world are flat. It is almost impossible to send the flat image source to the 3d LED spherical screen without processing.Fortunately, the ball is round, and it is impossible for any individual audience member to look at every corner of the LED ball screen at the same time. He can only see a small part of the surface of the ball.This is also related to the diameter of the ball screen, if the diameter of the ball screen is large, its effective concerned only about one 6 of the surface of the ball, presumably (because of the Angle of view), and five 6 can't see it or not its attention, because this five 6 respectively is, is on the left, on the back of the ball is on the right side, above and below.In this way, the following playback methods can be adopted: 1). Play six different image sources in six different areas of the sphere.2). Play three different image sources in three areas of the sphere (such as left back, top right and front bottom).3). Play 2 image sources in two areas (back, right, front, top, left and bottom).Of course, it is also possible to play a flat image source over the entire sphere like a watermelon skin LED spherical screen.


  3, LED the spherical design and graphic LED display screen resolution, which is closely related to the viewing distance of LED display, experience is the P2.5, 2.5 m outside watching, P6 6 m outside to watch, so P20 outdoor screen, so watch outside the 20 m, but the same is true in the real use, this is a vague choice, is qualitative, not quantitative, its basis as follows:

Like computer screens, LED displays display images that are composed of pixels, with each pixel composed of red, green and blue pixels.There is a certain distance between pixels, which we call point spacing PH.Let the resolution of the computer display screen be 1024 768, 1024 pixels in the horizontal direction and 768 pixels in the vertical direction.It is enough to express a sufficiently detailed picture.

If the vertical dimension of the computer display is 300mm, the spacing of pixels on the computer display is PH=300/768=0.39mm. PH is an important parameter of any digital display.

We have measured that the distance between the human eye and the computer display screen is D=450mm, so the Angle between the two adjacent pixels and the human eye is, so the equation = arctg0.39/450 (1)

  

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  If we place the computer display screen 30,000mm away from the operator, and replace the computer display screen with LED display or LED spherical screen, the distance between human eyes and LED display or LED spherical screen is 30,000mm.Thus, to be sure that the perceptual value of the image pixel stays the same (or its own resolution stays the same), the included Angle should also stay the same.The only thing that needs to change is the Ph.


  According to equation (1), we have the following equation: (15 = arctg0.39/450 =ArctgPh/30,000+450), so the Ph is about 26mm, that is, we will design the pixel spacing of the LED spherical screen to be 15~20mm, at this time, the clarity of the spherical screen is enough and reasonable.At this time, we can see the LED ball screen image definition from 30 meters away is the same as the effect we see in front of the computer.If the distance between human and LED spherical screen is other values, the Ph value can be calculated by referring to the above method.