Laptop display polarized?

Discussion in 'Computer Science & Culture' started by BenTheMan, Apr 11, 2010.

Thread Status:
Not open for further replies.
  1. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Ok, so I am sitting outside, wearing my (polarized) sunglasses, and programming.

    I made an interesting discovery: if I tilt my head 45 degrees to the right, the computer display disappears! Ah, the display must be polarized. Now I tilt my head 45 degrees to the left and HA! the brightness increases. QED.

    So the question is: is everybody's laptop display polarized? To check, get a pair of polarized sunglasses, and put them on. Is this common? Has anyone else noticed this? Is there a reason that manufacturers would polarize the displays?
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. kira Valued Senior Member

    Messages:
    1,579
    What happened when you tilt your head 45 deg to the TOP and what about to the DOWN also?

    Please Register or Log in to view the hidden image!

    I have no polarized sunglasses, can't check.

    Is it the computer display that is polarized or only the sunglasses, how one could tell? If without the sunglasses the display doesn't changed, it's only the sunglasses, right..?

    If it is the laptop, methinks the manufacturer made it (polarized display) to reduce the reflected lights so your eyes don't get tired easily.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Typically light comes in all different directions. Polarizers only let light of one direction in:

    Please Register or Log in to view the hidden image!



    If two polarizers are orthogonal, no light makes it through.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. kira Valued Senior Member

    Messages:
    1,579
    So if I draw it, the front view of the first, second, and third filter must be looked like this (in sequence), right?

    Please Register or Log in to view the hidden image!



    this is easyyy

    Please Register or Log in to view the hidden image!

    Please Register or Log in to view the hidden image!



    edit: add pic:

    Please Register or Log in to view the hidden image!

     
    Last edited: Apr 12, 2010
  8. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Yes that's (roughly) the correct picture.
     
  9. Trippy ALEA IACTA EST Staff Member

    Messages:
    10,890
    Fun things happen when you insert a third polarizing medium between the first two.

    You can get also sorts of fun colours that are related to the thickness of the material, and it's optical properties, and they for truely awesome piccies:

    Please Register or Log in to view the hidden image!


    Please Register or Log in to view the hidden image!


    Please Register or Log in to view the hidden image!

     
  10. Trippy ALEA IACTA EST Staff Member

    Messages:
    10,890
    Oh...

    And something that Ben was talking about...

    >_>

    Please Register or Log in to view the hidden image!

     
  11. phlogistician Banned Banned

    Messages:
    10,342
    All LCDs use polarising filters iirc, as the liquid crystal element twists when an electic potential is applied across it, and shift out of alignment with the polarising filter, and then it blocks light from the backlight.

    I'm glad they convention is 45° now, as I used to have a digital watch that had the filter arranged so that it blacked out when viewed though polarising shades, and I had to stick my elbow out and rotate the thing to tell the time, and must have looked a bit weird doing that!
     
  12. kira Valued Senior Member

    Messages:
    1,579
    Oww.. awesome pictures

    Please Register or Log in to view the hidden image!

     
  13. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Yeah it's something I never noticed, but now it drives me nuts!
     
Thread Status:
Not open for further replies.

Share This Page