高清電視係咪一定係 1920 x 1080

高清電視並不只是有1920 X 1080
1280 x 720也是高清格式之一

1920 X 1080也可以分為1080i/p
i=Interlace 隔行掃描
p=progressive scan 逐行掃描

其實一此LCD或PALSMA TV機身標示HD-Ready或HD Monitor 己經能顯720p以上的訊號輸入
但現在市面上般遍LCD或PALSMA TV的面板解像度也為1280X768或1366X768
這些電視也可以顯示到1920 X 1080的畫面
由於面板解像度不夠，可能畫面會發生裁減的情況發生
如畫面上下有少許不能顯示

現在近期只小數有LCD或PALSMA TV面板解像度達至1920 X 1080
而且售昂貴約三萬元以上

If you ask whether HD TV has to be 1920 x 1080. Yes. This is really true HDTV achieving point-to-point video output.

If you ask whether there are TV without 1920 x 1080 which are still HD compatible. Yes. They are not true HDTV but they support Full HD signal by processing the signal and output to the panels. Of course the quality, if other things being the same, will not be as good as a true HDTV.