Young Brunette Girl In The Glass Room With Blinds

Many window blinds are made with slats of fabric, wood, plastic or metal that adjust by rotating from an open position to a closed position by allowing slats to overlap. A roller blind does not have slats but comprises a single piece of material. Metal window blinds are often used outside of the house or business to protect against theft, temperature, vision, bad weather and fire (in fire-prone areas). Often these blinds are machine-operated, rather than hand operated.
The horizontal version uses a thin woven "ladder" system to suspend the slats and enable slats to be closed via a rotating drum to which each upper end of the woven ladder is wrapped and attached. A lift cord allows the blind to be pulled up and stack tightly to top of window when desired.
The vertical version uses a generally wider slat and has the added feature of being able to pull a cord to stack the slats together either to one side or to separate in the centre and stack on each end. This vertical blind allows rotation of slats by a rotating shaft in the upper head rail housing which runs through independent geared carriers that will convert twisting of tilt rail to a rotation of each individual slat in synchrony. The original vertical blinds were invented in Kansas City, Missouri, by Edward Bopp and Fredrick Bopp who held the original patent. The company name at the time was Sun Vertical. In the 1960s the patent and company was sold.
The term window blinds is also sometimes used, somewhat inaccurately, to describe window coverings generically—in this context window blinds include almost every type of window covering, e.g. shutters, roller blinds, roman blinds and of course, vertical and horizontal blinds.