In a window covering system and a window covering control apparatus thereof, the window covering control apparatus comprises a driving module, a damping output module, and a damping control module. The damping output module and the driving module are configured to operate simultaneously. The driving module may drive the damping output module to provide damping to the driving module. The damping control module comprises a control detecting unit and a fitting unit. The control detecting unit comprises a detecting portion and a stopper portion, which are detachably engaged. During an expansion of a covering material, the driving module drives the damping output module to provide damping to the driving module; when the stopper portion is driven apart by the detecting portion from the fitting unit, the driving module operates independently of the damping output module to stop the damping output module from providing damping.

A damping adjustment device for adjusting a damping force to a window covering system while the window covering system is expanding, wherein the damping adjustment device comprises a damping module comprising first and second damping units. The damping force is outputted by the damping module to the window covering system when the first and second damping units generate an interaction force in between by a relative motion therebetween. An adjusting module is connected to the damping module for operating with the damping module simultaneously, wherein the damping force from the damping module is adjusted by the adjusting module altering a relative position of the first damping unit and the second damping unit when the relative motion occurs therebetween. A window covering system comprises the damping adjustment device, wherein expansion speed of a covering material of the window covering system can be effectively controlled and adjusted by the damping adjustment device.

A damping device of a window covering is provided, including a headrail, a covering material, and a driving device, wherein the driving device is located in the headrail to raise and extend the covering material. The damping device is provided in the headrail, and includes a metal member and a magnetic member, wherein at least a magnetic pole of the magnetic member faces the metal member. The metal member is located within a magnetic field of the magnetic member. Either one or both the metal member and the magnetic member is drivable by the driving device to make the metal member and the magnetic member move relative to each other. Whereby, the damping device is able to provide a desired damping effect at different temperature or after a long period use, such that the rotation of the metal member and the movement of the covering material are slowed down.

A torque generation device includes a rotor connected to a shaft and rotatable about a rotary axis of the shaft; an external member disposed outside the rotor and rotatable about the rotary axis relative to the rotor; a magnetically responsive material in a gap between the rotor and external member; a magnetic field generating unit generating a magnetic field passing the magnetically responsive material; and an adjusting unit between the shaft and external member along an outer circumference of the shaft, wherein the adjusting unit has a containing space where an adjusting sealing member is provided, the magnetically responsive material is sealed in the gap, containing space, and path connecting these and in an adjustment space from a position where the adjusting sealing member is provided to the path, and a capacity of the adjustment space is changeable according to a change in volume of the magnetically responsive material.