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Scratch-proof rim for CDs

Simply manufacture CDs with a slightly thickened perimeter.
  [vote for,

When you take a CD and put it on any flat surface, it scratches. This is because it is completely flat. If the outside perimeter of the cd were slightly thicker than the rest of the disk then the valuable data-containing inner section would never come into contct with the desk/floor/other disk. I suppose it could also be done by adding a slightly thicker centre section too.
bs0u0155, Sep 28 2006

cushion them in dough. did I say +? http://www.doughnut...er_doughnut_640.gif
[po, Sep 28 2006]

CD description http://en.wikipedia.org/wiki/Compact_Disc
[Ling, Oct 01 2006]

D_Skin http://www.d-skin.com/index.htm
Add your own ring and skin to protect your disks [gardnertoo, Oct 01 2006]


       Make it the interior and make it slightly cone shaped, convex on the bottom, concave on the top, then CDs could stack too!
Galbinus_Caeli, Sep 28 2006

       class! says I, who has not the 1st idea how these things work.
po, Sep 28 2006

       A scratch on the back of a CD will do more damage than the front...
Jinbish, Sep 29 2006

       Jinbish, I didn't know that. But this idea should help with that, too. By the way, the new device could use the old anagram of Floppy Disk = Frisbee Disk. When they do get scratched, they would be great for throwing around the office.
Ling, Sep 29 2006

       CDs (certainly the one's I'm toying with) already have a thicker centre so that they hold each other apart when they stack and, if put down carefully, only contact a flat surface in the non-playing area. Raising the outside, too, sounds like a good idea to me. [+]
st3f, Sep 29 2006

       [Ling]: Well, as far as I can remember it's true. The logic here comes from the fact that the strip of magneto-optic material that has the information on it can be closer to the non-playing surface. So a scratch to the playing side will, more likely, damage the plastic and therefore the path of light will be dispersed, reflected, or otherwise distorted. This can arise with an unplayable portion. CD players will have a tolerance for this (better opics etc.). A scratch on the non-playing side will, instead, actually damage the bit that holds the information - no tolerance.
Jinbish, Sep 29 2006

       [Jinbish][Ling]: A CD, unlike a DVD, is essentially a piece of metal foil attached to a polycarbonate disk. The disk supplies mechanical strength and protects the data side of the foil, but all of the information is on the foil, not the polycarbonate.   

       Even an incredibly deep gouge on the polycarbonate side of the disk could be repaired by filling it with a material of similar optical characteristics. Even a small scratch on the metal side, however, may penetrate it completely and destroy the data layer that's underneath.   

       Another thing to consider is that some brands of CD are succeptible not only to scratching but also to delamination. If the foil isn't well glued to the disk, it may be pulled off. This can occur if the foil side of the disk sticks to something like another disk or a cheap plastic sleeve, or the disk has a label attached which shrinks after application.
supercat, Sep 29 2006

       For the non data side you could always extend the rim above and below the plane of the disk. It may affect packing densities though.
bs0u0155, Oct 01 2006

       Supercat, I just checked Wiki, and saw that there is only a thin lacquer film over the foil on the top surface. Well, I guess I'll have to stop scratching my name on the top from now on...
Ling, Oct 01 2006

       An aftermarket product exists called D-skin, which combines 1) a thin transparant skin to cover the face of the disk with 2) an outer ring edge which acts both to attach the skin and lift the disk off surfaces. (See link) Like your idea, this product does not affect playability of the disks, and adds only a little thickness to deal with for stacking. Since it is a seperate device added to the disk by the consumer, it doesn't count as baking your idea, but it's a step in that direction. The D_skin has the additional benefit of being removable if it becomes scratched itself (giving it's life to protect your disk). It can be moved from one disk to another, but they don't reccomend it.
gardnertoo, Oct 01 2006

       I thought for a while you might accomplish the same thing with just a few bumps around the rim, but then realized that cds stacked out of alingment with each other will still touch, and the bumps actually cause more scratches than they prevent.   

       So don't do that, in case you think of it.
oxen crossing, Oct 04 2006

       You mean in the same way that the pieces from the original connect 4 game were stacked, [oxen]?   

       That could work well provided the lumps were marginally deeper than the grooves.
fridge duck, Oct 04 2006


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