A stereoscopic 3D display technology that separates the stereo frames by alternating the viewing path to each eye. Used for 3D gaming and the first 3D TVs, liquid crystal (LC) shutter glasses are synchronized with alternating stereo frames on screen by an infrared (IR) emitter on the monitor or TV. Ceiling-mounted projectors use radio signals rather than IR (see
RF shutter glasses).
Alternate Open and Closed
The liquid crystal lenses turn black to alternately block the light from each eye. The "active" refers to the electronic circuit in the glasses, whereas "passive" glasses have no circuits (see
polarized 3D). See
3D visualization,
anaglyph 3D,
lenticular 3D,
parallax 3D and
3D glasses.
No Flicker or Ghosting and True Colors
By supporting 120 frames per second (fps), active 3D glasses deliver the full resolution at 60 fps to both eyes. Active 3D glasses also eliminate the ghosting sometimes associated with passive polarized 3D methods, and because the frames are not modified in any manner, the viewer sees the full color spectrum. Many users claim active 3D is the best 3D experience; however, light is blocked half the time, causing the screen to be dimmer than polarized 3D. In addition, some people notice the lens flicker.
Alternate Left and Right
Every active 3D monitor and TV emits infrared (IR) signals to the shutter glasses, although starting in 2011, Samsung switched to Bluetooth. The blue arrows above are not the emitters; they show the stereo frames and alternating eyes. Active glasses are heavier and more expensive than passive polarized glasses and must be periodically recharged like all battery-operated devices.
Active 3D Gaming
Like all active 3D shutter glasses, NVIDIA's 3D Vision gaming system alternates 60 left frames with 60 right frames every second. See
LC shutter glasses.
(Image courtesy of NVIDIA Corporation.)
Active 3D Simulation
This CAVE system teaches people how to operate a Caterpillar bulldozer. Wearing shutter glasses, the man thinks the wheel on the left is the one he is turning. See
CAVE.
(Image courtesy of Fakespace Systems Inc.)