2006-12-11 09:56:06 · 5 answers · asked by dips5210 1 in Consumer Electronics ➔ TVs
The reason for this goes back to the beginning of television; the first TVs were made with round-faced picture tubes; in the early days that was the only way the tubes could be made. A rectangular mask was placed in front of the tube to conceal the blank areas of the screen. Because the size of the tube (diameter of the face) was the critical parameter for the set, that was used to specify the picture size. Of course, the diameter of the tube is also the diagonal of the picture. So when you bought a 12" TV, you bought a TV with a 12" CRT. (At one time Zenith introduced a TV with a round picture to give the appearance of a larger picture; of course, the corners of the picture were cut off.)
Eventually, tubes with rectangular faces were developed, but because the standard had been established and people were familiar with picture sizes specified as diagonal, the system was continued.
As long as the picture aspect ratio was constant, it didn't matter. Now however, we have both 4:3 (standard) and 16:9 (widescreen) TV sets, and diagonal measurement is decepetive. A picture of a given diagonal will appear smaller on a widescreen than a standard screen. If you want the picture have the same apparent size, a widescreen picture should be 20% larger (in diagonal) than a standard picture.
Note: Diagonal measurement was being used long before the FCC established it's rule. Quote from the report:
"When the Commission initially promulgated the Rule in 1966, most television manufacturers measured the dimensions of their television sets diagonally, just as they do today."
2006-12-11 19:01:03 · answer #1 · answered by gp4rts 7 · 2⤊ 0⤋
Tv Measured Diagonally
2017-01-19 09:44:24 · answer #2 · answered by ? 4 · 0⤊ 0⤋
It was instituted by the government in 1966 to prevent manufacturer's deceptive claims about picture size. The old technology didn't work in the corners of the picture tube very well back then, so you'd end up with dark areas around the picture when it was adjusted right.
The companies would claim the the tube was larger than the picture could be and lots of people didn't understand that. Like saying you had a 27 in diagonal picture tube when the picture was only 25 in diagonal. If you thought you were getting a 27 in picture, you were wrong.
2006-12-11 19:05:06 · answer #3 · answered by sd_ducksoup 6 · 0⤊ 0⤋
This is just a guess but probably so that the TV's could be marketed as having a larger screen.
2006-12-11 10:04:43 · answer #4 · answered by Anonymous · 0⤊ 0⤋
To make them sound larger than they actually are. It's a sales ploy.
2006-12-11 10:03:53 · answer #5 · answered by Lonnie P 7 · 1⤊ 0⤋