What is the name of the curtain in front of the crown worn by the ancient emperor?

On behalf of the emperor Pingmian, also known as "Pingtianguan", ten white jade beads were hung. Also known as "Tian Tongguan" and "Pingguan". Started in Qin and Han Dynasties, commonly known as "Pingtianguan". At this time, the crowns are all seven inches wide, two inches long, four inches in front and three inches in back, and twelve white jade beads, the color of which is Tuan Ying. Three princes and seven princes, sapphire is a pearl; Doctor Qing is five years old, and jet is a pearl. There are colorful tassels before and after, hanging sideways. Suburb heaven and earth, Zongsi, Tang Ming, then the crown. " Emperors of various dynasties established by the Han nationality wore flat crowns. Two flat crowns were unearthed from the coffins of Zhu Yijun, Ming Shenzong and Dingling in the Ming Tombs, and their shapes were exactly the same as those in the pre-Qin and Zhou Dynasties. Flat crown, also known as crown, is the highest ceremonial crown of ancient Han emperors. Emperors before Sui and Tang Dynasties usually wore flat crowns in court, but later emperors only wore them in court ceremonies, such as enthronement ceremonies, big weddings, and worship to heaven.