• cmnybo@discuss.tchncs.de
    link
    fedilink
    English
    arrow-up
    26
    ·
    2 days ago

    How is that even supposed to work? The laser beam has to be reflected back down to the sensor in order to read the CD.

    • aeronmelon@lemmy.world
      link
      fedilink
      English
      arrow-up
      33
      ·
      edit-2
      2 days ago

      Translucent != transparent, but you might be on to something.

      Maybe it works better on slim drives with a lower ceiling. Larger drives with space above the disc might allow the laser to refract and generate garbage.

      Edit: okay, nevermind, it really is completely transparent. Here’s a picture:

      This is actually stupid. At no point during the manufacturing process did anyone mention how CDs work?

      The vinyl being transparent is fine, vinyls work by a needle touching the surface, optical discs work by… optics!

      • bdonvr@thelemmy.club
        link
        fedilink
        English
        arrow-up
        8
        ·
        2 days ago

        I mean the CD does work. But not with all players… Not sure what makes some work and some not. Laser wavelength?

        • MotoAsh@lemmy.world
          link
          fedilink
          English
          arrow-up
          12
          ·
          2 days ago

          Most likely the sensitivity of the electronics and whether they consider the surely weak signal noise.

    • SheeEttin@lemmy.zip
      link
      fedilink
      English
      arrow-up
      7
      ·
      edit-2
      2 days ago

      CD players use 780 nm light, which is infrared. What is transparent in visible light may be reflective in infrared. Obviously, this material is not sufficiently reflective.