Multi-viewer displays allow multiple people to see 3D content simultaneously without glasses by projecting different viewpoints across a wide viewing zone. Unlike single-viewer systems, they do not rely on eye tracking, instead using dense viewpoint replication to accommodate multiple observers.
Core Technologies
1. Parallax Barriers
- A mask with precision slits blocks light to direct different pixel columns to different angles.
- Pros: Simple, compatible with existing LCDs.
- Cons: Low brightness, limited viewing angles.
2. Lenticular Lens Arrays
- Cylindrical lenses refract light into multiple viewing zones (e.g., 8-view, 16-view).
- Pros: Brighter than parallax barriers, smoother motion parallax.
- Cons: Fixed sweet spots, moiré artifacts if misaligned.
3. Directional Backlight (Light Field Displays)
- Uses microlens arrays or diffractive optics to project multiple views.
- Pros: High brightness, scalable to many views.
- Cons: Complex optics, high computational load.
4. Super Multi-View (SMV) & Holographic Approaches
- Dense viewpoints (50+ views) for natural motion parallax.
- Pros: Smooth 3D, reduced accommodation-vergence conflict.
- Cons: Extremely high resolution & bandwidth requirements.
Key Challenges
✔ Viewing Freedom – Must balance between view density and resolution.
✔ Crosstalk Management – Minimizing ghosting between adjacent views.
✔ Brightness & Efficiency – Avoiding light loss from barriers/lenses.
Applications
- Digital signage (retail, exhibitions)
- Collaborative design (3D CAD, medical imaging)
- Entertainment (gaming, immersive experiences)
