The process gradually became obsolete after the development of the Solvay process.
==Glej tudi==* Head-mounted display (HMD) - precej podobna naprava, le da je nameščena na glavo (ne na čelado)* Head-up display (HUD)* Google Glass* VRML==Reference====Bibliografija==* Head Mounted Displays: Designing for the user; Melzer and Moffitt; McGraw Hill, 1997==Zunanje povezave==* HMD/headset/VR-helmet Comparison Chart* User survey of HMD requirements* Resolution analysis for HMD helmets / Comparison Chart* Vision Systems International