What does free HD mean?

Free HD is aimed at the screen resolution of flat-panel TV, and two conditions must be met at the same time:

First, the physical resolution of the screen is1920×1080;

Second, the TV internal circuit can process and output the picture signal in 1080p format. The overall physical resolution of the display screen should reach 1920× 1080P, that is, the horizontal resolution should reach 1920 pixels and the vertical resolution should reach 1080 scanning lines.

Several common TV scanning formats:

D 1 is in 480i format with the same definition as NTSC analog TV. There are 525 vertical scanning lines, showing 483 vertical scanning lines, 4: 3 or 16: 9, interlaced /60Hz and line frequency15.25khz..

D2 is in 480P format, which is the same as that of progressive DVD. There are 525 vertical scanning lines, showing 480 vertical scanning lines, 4: 3 or 16: 9, with a resolution of 640×480, line by line /60Hz and a line frequency of 31.5khz..

D3 is in the format of 1080i, which is a standard digital TV display mode. 1 125 vertical scanning line, 1080 visible vertical scanning line, 16: 9, and the resolution is1920×/kloc.

D4 is a standard digital TV display mode, with 720p format, 750 vertical scanning lines, 720 visible vertical scanning lines, 16: 9, resolution 1280×720, line by line /60Hz and line frequency of 45KHz.

D5 is in the format of 1080p, which is a standard digital TV display mode. The vertical scanning line is 1 125, and the visible vertical scanning line is 1080, 16: 9, and the resolution is1920×/.

There is also 576i, which is the standard PAL TV display mode, with 625 vertical scanning lines and 576 visible vertical scanning lines, 4: 3 or 16: 9, interlaced /50Hz, and recorded as 576i or 625i.

HDTV refers to the TV standards that support 1080i, 720P and 1080P. Nowadays, large-screen LCD TVs generally support 1080i and 720P, while some commonly known "full HD" refers to TVs that support 1080P output. At present, the digital signal of HDTV can support up to 720P, but none of them supports 1080P.