Patent ID: 8002012

Claim:
A Venetian blind, comprising: an elongate upper rail; a lower rail spaced from the upper rail at a lower side; a slat assembly which is located between the upper rail and the lower rail and has slats and a lift cord assembly passing through the slats, and two coupling cords; an automatic retraction means which is located in the upper rail and coupled with the slat assembly and has a retaining set, a transmission set pivotally coupled inside and a reel set mounted on the retaining set, the transmission set and the reel set are wound by the lift cord assembly; and a slat opening/closing control device which is located in the upper rail and includes a transmission wheel engaging with the transmission set, a helical elastic adjustment member installed on the transmission wheel, and a first bevel gear correspondingly fastened to the adjustment member and engaging with the reel set; wherein the slats are inclined to a desired angle by the coupling cords through rotating of the reel set that is driven by the first bevel gear rotating with the adjustment member and the transmission wheel transmitted by the transmission set through pulling of the lift cord assembly when the lower rail is moved relative to the upper rail.