Motorized venetian blind

A motorized venetian blind, comprising:

• a headrail;
• a bottom rail, situated below the headrail through a front pull cord and a rear pull cord which are respectively connected to a first reeling wheel and a second reeling wheel, wherein the first reeling wheel and the second reeling wheel are disposed on the headrail;
• plural slats, suspended by a ladder cord and located between the headrail and the bottom rail, wherein the ladder cord comprises a front warp and a rear warp each have one end connected to a tilting wheel disposed on the headrail;
• the slats are located between the front warp and the rear warp;
• the front warp and the front pull cord pass one side of the slats, and the rear warp and the rear pull cord pass the other side of the slats;
• a first lifting electric machine, configured to control the first reeling wheel to rotate for performing one of retracting the front pull cord and releasing the front pull cord;
• a second lifting electric machine, configured to control the second reeling wheel to rotate for retracting the rear pull cord and releasing the rear pull cord;
• a tilting electric machine, configured to control the tilting wheel to rotate for generating a relative movement that is substantially vertical of the front warp and the rear warp of the ladder cord, whereby the slats are tilted between a horizontal position and a closed position;
• a first detector, configured to detect tension of the front pull cord;
• a second detector, configured to detect tension of the rear pull cord;
• and
• a controller, electrically connected to the first lifting electric machine, the second lifting electric machine and the tilting electric machine;
• wherein the controller transmits a first tilting signal to make the tilting electric machine control the tilting wheel to rotate in a first direction in response to only the second detector between the first detector and the second detector detecting tension smaller than a preset value while the first reeling wheel and the second reeling wheel are stationary, whereby the rear warp is moved upwardly relative to the front warp to tilt the slats;
• the controller transmits a second tilting signal to make the tilting electric machine control the tilting wheel to rotate in a second direction in response to only the first detector between the first detector and the second detector detecting tension smaller than the preset value while the first reeling wheel and the second reeling wheel are stationary, whereby the front warp is moved upwardly relative to the rear warp to tilt the slats;
• wherein either or both of the following situations occur:
• when the tilting electric machine controls the tilting wheel to tilt the slats to the closed position in response to the first tilting signal from the controller, the controller further controls the second lifting electric machine to drive the second reeling wheel to rotate for retracting the rear pull cord, whereby the bottom rail is tilted towards a same direction as a tilting direction of the slats to a substantially vertical position and partially overlaps an adjacent one of the slats, or/and when the tilting electric machine controls the tilting wheel to tilt the slats to the closed position in response to the second tilting signal from the controller, the controller further controls the first lifting electric machine to drive the first reeling wheel to rotate for retracting the front pull cord, whereby the bottom rail is tilted towards the same direction as the tilting direction of the slats to the substantially vertical position and partially overlaps an adjacent one of the slats.