A spring drive system for a window shade includes a housing, a plurality of rotary members, a spring and a latch. The rotary members are rotationally linked to one another and pivotally connected with the housing, wherein the rotary members include a rotary drum that is connected with a suspension member and is rotatable relative to the housing for winding or unwinding the suspension member. The spring is assembled with the housing, and can bias the rotary drum in rotation for winding the suspension member. The latch is assembled with the housing, the latch being movable to engage with and disengage from one of the rotary members to respectively prevent and allow rotation of the rotary drum.

The invention relates to a screen, comprising a first control unit (610) comprising a first drive shaft (612) and at least one first cord spool (630) rotatable with the first drive shaft for winding and unwinding a first lift cord (634) extending between a head rail and a middle rail; a second control unit (620) comprising a second drive shaft (622), and at least one second cord spool (632) rotatable with the second drive shaft for winding and unwinding a second lift cord (636) extending between the head rail and the bottom rail; and a shaft rotation limiting system (100) comprising a threaded shaft arranged on and rotatable in unison with one of the first and the second drive shafts, a coupling element threaded on said threaded shaft, wherein the coupling element is associated with and rotatable in unison with the other drive shaft.

The invention relates to a screen, comprising a first control unit (610) comprising a first drive shaft (612) and at least one first cord spool (630) rotatable with the first drive shaft for winding and unwinding a first lift cord (634) extending between a head rail and a middle rail; a second control unit (620) comprising a second drive shaft (622), and at least one second cord spool (632) rotatable with the second drive shaft for winding and unwinding a second lift cord (636) extending between the head rail and the bottom rail; and a shaft rotation limiting system (100) comprising a threaded shaft arranged on and rotatable in unison with one of the first and the second drive shafts, a coupling element threaded on said threaded shaft, wherein the coupling element is associated with and rotatable in unison with the other drive shaft.

A window covering includes a fixed rail, a covering material, a lifting cord and a winding mechanism, wherein the covering material is positioned under the fixed rail, and the winding mechanism includes a reel, a rotating member and a stopper. The reel is adapted to wind up or release the lifting cord, in order to drive the covering material to move toward the fixed rail to fold, or to move away from the fixed rail to unfold. The rotating member passes through the reel. The stopper is operably pivoted relative to the rotating member. When the rotating member rotates independently from the reel, the stopper is driven to pivot, and is protruded from a surface of the rotating member, and the stopper would abut against a block of the fixed rail to stop the rotation of the rotating member. Therefore, when a covering material of the window covering is unfolded and meets an obstacle, the covering material could stop unfolding automatically.

A window covering includes a fixed rail, a covering material, a lifting cord and a winding mechanism, wherein the covering material is positioned under the fixed rail, and the winding mechanism includes a reel, a rotating member and a stopper. The reel is adapted to wind up or release the lifting cord, in order to drive the covering material to move toward the fixed rail to fold, or to move away from the fixed rail to unfold. The rotating member passes through the reel. The stopper is operably pivoted relative to the rotating member. When the rotating member rotates independently from the reel, the stopper is driven to pivot, and is protruded from a surface of the rotating member, and the stopper would abut against a block of the fixed rail to stop the rotation of the rotating member. Therefore, when a covering material of the window covering is unfolded and meets an obstacle, the covering material could stop unfolding automatically.

An integrated-optics MEMS-actuated beam-steering system is disclosed, wherein the beam-steering system includes a lens and a programmable vertical coupler array having a switching network and an array of vertical couplers, where the switching network can energize of the vertical couplers such that it efficiently emits the light into free-space. The lens collimates the light received from the energized vertical coupler and directs the output beam along a propagation direction determined by the position of the energized vertical coupler within the vertical-coupler array. In some embodiments, the vertical coupler is configured to correct an aberration of the lens. In some embodiments, more than one vertical coupler can be energized to enable steering of multiple output beams. In some embodiments, the switching network is non-blocking.

An integrated-optics MEMS-actuated beam-steering system is disclosed, wherein the beam-steering system includes a lens and a programmable vertical coupler array having a switching network and an array of vertical couplers, where the switching network can energize of the vertical couplers such that it efficiently emits the light into free-space. The lens collimates the light received from the energized vertical coupler and directs the output beam along a propagation direction determined by the position of the energized vertical coupler within the vertical-coupler array. In some embodiments, the vertical coupler is configured to correct an aberration of the lens. In some embodiments, more than one vertical coupler can be energized to enable steering of multiple output beams. In some embodiments, the switching network is non-blocking.

In various aspects, a covering for an architectural structure includes a bottom rail assembly that can be efficiently and effectively assembled during manufacturing of the covering. Specifically, in one embodiment, the bottom rail is configured such that one or more operating system components of the covering can be mounted within and directly supported by the bottom rail. In addition, a separate cover may be coupled to the bottom rail during the assembly process.

In various aspects, a covering for an architectural structure includes a bottom rail assembly that can be efficiently and effectively assembled during manufacturing of the covering. Specifically, in one embodiment, the bottom rail is configured such that one or more operating system components of the covering can be mounted within and directly supported by the bottom rail. In addition, a separate cover may be coupled to the bottom rail during the assembly process.

A shade configured to be rolled up or down by a user includes a plurality of slats, a plurality of weaving cords which attach the plurality of slats together, at least one strap including a top end and a bottom end, the top end being attached to one of the plurality of slats at a back side of the shade and the bottom end being a free end including a connector. A method of using the shade includes rolling up the shade to a first rolled up position and securing the rolled up portion of the shade by wrapping the strap around the rolled up portion and securing the strap to a front side of the shade. A fastener may also be used to secure a rolled up portion of the shade.