You heard wrong :). Voila ( click for descriptions of the individual pieces ):
http://www.turkishculture.org/weapons/armor/armor.html
Indeed the burgonet, an open-faced helmet that became a standard part of the equipment for lighter calvary in Europe, probably derives from Turkish influence.
Mail shirts were in use ( often under clothes or cloth covering ) even among the earliest Arab armies, let alone 700 years later when the Ottomans began to make their move. Further the early Ottoman armies frequently took on an international flavor:
As Tedali reports, while there were 200,000 men present on the Turkish side, only 60,000 were soldiers ( and of those 30,000 to 40,000 were calvary ): “A quarter of them were equipped with coats of mail or leather jackets. Of the others, many were armed after the fashion of France, some after the fashion of Hungary and others again had helmets of iron, and Turkish bows and crossbows. The rest of the soldiers were withoiut equipment, except that they had shields and scimitars, which are a kind of Turkish sword.”
For that matter such equipment was not all that different from that of the armies they faced, a la the 14th and 15th century Byzantines:
*…The mixing of Norman, Italian, Turkish, and nomadic influences with indigenous developments produced a cosmopolitan style…
…Late Byzantine soldiers wore a variety of chain mail hauberks. Some were short-sleeved, others were long-sleeved and worn sometimes with either attached or seperate mittens. Some hauberks extended only slightly below the waist while others fell almost to the knees. In figure 4 the soldier wears what appears to be a fabric-covered mail shirt or hauberk that suggests Islamic influence. According to the historian Doukas, the Serbs who fought on the Ottoman side at the battle of Ankara were impervious to arrows because they were covered in “black iron”, that is, chain mail…
Some late Byzantine warriors wore cuirasses on top of or instead of mail hauberks. These cuirasses were not the archaic, stylized type so often depicted in Byzantine art: the old Roman-style cuirass of metallic scale or lamellar, or of forged iron or bronze, were no longer in use, except perhaps for ceremonial armor. Rather, the common late Byzantine style was a metallic or hardened leather cuirass of a distinctive Oriental ( Turco-Mongol ) form.*
Emphases added. The above quotes from The Late Byzantine Army: Arms and Society, 1205-1453 by Mark C. Bartusis ( 1992, University of Pennsylvania Press ).
Now it is likely true that the Ottoman armies overall were more lightly armored at the absolute end and perhaps on average by the Europeans ( outriders and raiders were often stripped down, as was expendable light infantry ). But articulated full-plate was rare ( very expensive ), a late development quickly trumped by firearms and even everyday heavy knights were vulnerable to the right tactics, as the Ottomans proved at Nicopolis in 1398, just to name one encounter. They were slow and quickly exhausted, which meant they could be strung out and then swarmed by more mobile foes.
