Window blind system

A method of controlling a light shading effect of a window blind system, comprising the steps of:

• (a) providing a shading arrangement which comprises a top transverse supporter, a base member, a plurality of first and second slats aligning in a sequential manner, and an operating unit for selectively folding said first and second slats between a shading position and a folded position, wherein a light passing gap is defined between said first and second slats for allowing light passing therethrough;
• (b) providing a first hanging unit for supporting said slats underneath said top traverse supporter, wherein said first having unit comprises a first member for downwardly extending from said top traverse supporter and a plurality of traverse cords spacedly supported by said first member to respectively support said slats suspendedly underneath said top traverse supporter, wherein each of said first slats is positioned between every two of said second slats, wherein said light passing gap is defined between every two of said two traverse cords for allowing light passing between a gap between every two of said adjacent first and second slats;
• (c) providing a second hanging unit for only controlling said first slats, wherein said second hanging unit comprises a second member for downwardly extended from said top traverse supporter and a plurality of slat seats spacedly supported by said second member for respectively supporting said first slats, wherein a distance between every two of said slat seats is double of a distance between every two of said two traverse cords;
• (d) selectively controlling said second hanging unit to overlap said first slats with said corresponding second slats respectively to double said light passing gap as a distance between every two of said second slats so as to enhance said light passing therethrough, wherein said second hanging unit is selectively controlled by an alternation-operating device connected to said second hanging unit to move said first slats to overlap with said second slats respectively, wherein said second hanging unit is lifted upwardly with respect to said top traverse supporter for only lifting up said first slats to overlap underneath said corresponding second slats respectively so as to double said light passing gap;
• and
• (e) adjusting a tilt angle of each of said slats through a slat angle adjuster which is coupled with said slat first and said second hanging units, wherein said slat angle adjuster comprises an angle rotor rotatably mounted at said top traverse supporter such that when said angle rotor is driven to rotate, each of said first and second slats are driven to tilt in an inclined manner, wherein said alternation-operating device comprises an actuation member having an upper end attached to said hanging unit to control said first slats and arranged in such a manner that said upper end of said actuation member detachably couples to said angle rotor to control said tilt angles of said first and second slats, wherein said alternation-operating device further comprises a locking member provided on a side of said shading arrangement to detachably engage with said actuation member so as to securely lock up said first slats overlapping with said second slats respectively, wherein said locking member comprises a locker ring, which is adapted for mounting on a side of a window frame, having an inner locking threaded portion, wherein said actuation member is slidably engaged with said locker ring and has an outer locking threaded portion arranged to engage with said inner locking threaded portion of said locker ring so as to lock up said actuation member with said locker ring.