# dumb question: What makes flat-screen TV's so much heavier than standard tubes?

Discussion in 'Archived Threads 2001-2004' started by BrandonRM, Dec 19, 2002.

1. ### BrandonRM Auditioning

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A flat-screen (not flat-panel a la LCD or plasma... just FST) 27" TV weighs about 100lb... but a 27" TV of the same size (dimensions HxWxD) that has a curved screen weighs only about 70lb...

I know the reason that TV's started out with the curved screen is because it's a part of a sphere, and the electron guns can most easily do their job if all points they must fire at are the same distance from the guns, and I'm sure that the fact that flat-screen TV's impede on this probably has something to do with the weight, but I'm dumb and don't know what it is exactly that causes the flat-screen to weigh 30 lbs more...

Just curious; sorry this is deviant from the general type of topic in this forum; if there's a better forum for this, feel free to move the thread there.

Thanks
Brandon

2. ### Ross E Auditioning

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Brandon,

This really isn't a dumb question, as the answer lies in some pretty deep physics. But the thing to remember about a picture tube is that it is a vacuum tube. There is nothing but empty space inside.

The real reason old TVs were curved is because a spherical shape can stand up to the air pressure pushing against it much better than a flat screen can.

If my calculations are correct, a 30 inch TV is really 18in x 24in (3x4=5). Therefore it has 432 square inches of surface area. At an average atmospheric pressure of 30 lbs. per inch, that equals 12,960 pounds of pressure pushing against the TV screen, with only the strength of the glass to hold it up. A curved shape can do this fairly easily, but a flat screen can't. So the glass has to be much thicker.

Of course I could be completely wrong.

3. ### Joe Tilley Supporting Actor

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As Ross said the glass has to be much thicker to withstand the vacume of the tube, hence the extra weight.

4. ### ChrisWiggles Producer

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Needless to say.... you don't want to hit your screen with large metal objects and break it. I think i remember howstuffworks.com had a little video where they tried "shooting your tv." Anyway, the point is it's not smart to take that saying literally

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