06-03-2012, 12:48 PM
Imagine a plane perpendicular to the computer screen at the level where the "invisible" text is located.
If I look at the screen from above the imaginary plane I cannot read the text; but if I look from below the plane I can read it.
I suspect the explanation has something to do with the polarity of the crystals in an LCD screen and of the material forming the surface of the screen, but I'll leave proper scientists to confirm whether or not that is the case.
It may be that on some laptops the text can be read from above the plane but not from below; it may also be that on an old-fashioned cathode-ray screen the text is visible from all angles or invisible from all angles.
If I look at the screen from above the imaginary plane I cannot read the text; but if I look from below the plane I can read it.
I suspect the explanation has something to do with the polarity of the crystals in an LCD screen and of the material forming the surface of the screen, but I'll leave proper scientists to confirm whether or not that is the case.
It may be that on some laptops the text can be read from above the plane but not from below; it may also be that on an old-fashioned cathode-ray screen the text is visible from all angles or invisible from all angles.