Parallax barriers are a glasses-free 3D display technology that uses a precisely aligned slatted barrier (similar to a window blind) placed in front of an LCD screen. The barrier blocks specific pixels from reaching each eye, creating binocular disparity and a stereoscopic effect.
Advantages: Simple design, low cost, and compatibility with existing LCD panels.
Disadvantages: Reduced brightness, limited viewing angles, and lower resolution (half the effective pixels per eye).
Used in early Nintendo 3DS and some autostereoscopic signage, though largely replaced by lenticular lenses in modern displays due to better light efficiency.
