In Timothy's fictional account of the attack on his ship, the SS Vico, he claimed that an unidentified species came out of nowhere, fired at their ship, before boarding it. His description of the unknown forces was "they had purple helmets on and phaser rifles." (TNG: "Hero Worship")
The script of Star Trek VI refers to this form of Klingon helmet simply as a "light helmet."  These were actually props whose layout was designed by the Oakley manufacturing company. (The Making of the Trek Films, 3rd ed., p. 128) The mining helmets were constructed by props master Greg Jein. (The Art of Star Trek, p. 267) He recalled, "The helmets were designed on a computer [at Oakley], which then carved the pattern by catalyzing liquid resin. When we got the pattern from Oakley, we could still see all the strata lines on it, so we molded it, cast up a number of copies of the helmet and added working lights and other details." (The Making of the Trek Films, 3rd ed., p. 128)
Ridged helmets similar to the alternate reality helmets were worn in the Universal Studios attraction Star Trek Adventure, actors playing Klingons wore ridged helmets covering their foreheads. These helmets did not cover the actors' noses though.