Patent ID: 12237800

DETAILED DESCRIPTION

A first embodiment of an electric window covering100of the present disclosure is shown inFIGS.1-10, which includes a headrail10, a covering material12, a rotating member14, a driving device16, and a control device24. Some components are drawn with dashed lines for illustrative purposes.

The headrail10is realized with a frame having a receiving space10atherein. The covering material12is located below the headrail10. The covering material12has an upper end close to the headrail10and a lower end12aaway from the headrail10.

The rotating member14is provided in the receiving space10aof the headrail10, and includes a spindle142and two spools144. The spindle142extends in a longitudinal direction of the headrail10. The spools144fixedly fit around the spindle142, and are located apart from each other by a suitable distance. Each of the spools144has a cord44wound therearound, wherein an end of each of the cords44is fixed at the corresponding one of the spool144.

Each of the cords44passes through a cord hole102(as shown inFIG.9) located at a bottom of the headrail10, and goes through the covering material12in a vertical direction, with another end thereof reaching the lower end12aof the covering material12. The lower end12aof the covering material12includes a bottom rail122, wherein the other ends of the cords44are connected to the bottom rail122. In some embodiments, the numbers of the spools144and the cords44are not limited to be two as exemplified above, and could be realized with only one or more than two spools and cords.

The driving device16is provided in the receiving space10aof the headrail10, and includes a motor20, and a decelerator22. The motor20is connected to the spindle142through the decelerator22. A shaft202of the motor20is connected to the decelerator22, and the decelerator22is connected to an end of the spindle142. In an embodiment, the decelerator22is a planetary gearing decelerator. In other embodiment, the decelerator22may be realized with other suitable structures. The motor20drives the spindle142to rotate, and the spools144fixedly fitting around the spindle142would also be driven to rotate, whereby the spools144could release or reel in the cords44to expand (close) or retract (open) the covering material12. A length of a segment of each of the cords44which can be fully released from the corresponding spool144due to the driving of the motor20is slightly longer than a length of the covering material12when it is fully expanded or lowered. The aforementioned length of the segment of each of the cords44released from the corresponding spool144refers to the segment length that each cord44released from the respective spool144by the driving of the motor20.

The control device24is provided in the receiving space10aof the headrail10, and is electrically connected to the motor20, wherein the control device24configures the motor20to activate, whereby to drive the covering material12to expand or retract. Furthermore, the control device24configures the motor20to stop moving when a moving speed of the lower end12aof the covering material12decreases and such a situation lasts for a predetermined time. In this way, when the covering material12is expanded to eventually reach a fully expanded position, is retracted to eventually reach a fully retracted position, or encounters resistance during its expanding or retracting, the control device24could stop the covering material12from moving because the moving speed of the lower end12aof the covering material12decreases for equal to or longer than the predetermined time. Whereby, the covering material12could stay in a fully expanded state or a fully retracted state. In addition, the covering material12would not exert further force on the blocking object that it bumps into during the expanding or retracting processes, and the electric window covering100could be prevented from being damaged.

In an embodiment, the control device24includes a control module26and a trigger detecting module30. The control module26configures the motor20through a driving circuit28to drive the spindle142of the rotating member14to rotate in a first rotating direction D1or a second rotating direction D2. When the spindle142of the rotating member14rotates in the first rotating direction D1, the spools144which fixedly fit around the spindle142would be driven by the spindle142to rotate as well, whereby to reel in the cords44and therefore to retract or raise the covering material12. When the spindle142of the rotating member14rotates in the second rotating direction D2, the spools144which fixedly fit around the spindle142would be driven by the spindle142to release the cords44, whereby to expand or lower the covering material12.

The trigger detecting module30is electrically connected to the control module26, and is configured to detect a rotating speed of the rotating member14or a rotating speed of the shaft202of the motor20. While the covering material12is being retracted or raised, the control module26could, according to the detected rotating speed, determine whether the moving speed of the lower end12aof the covering material12is lower than the moving speed moments ago, and whether such a situation lasts for the predetermined time. The control module26could learn if the covering material12has reached the fully retracted position or if it encounters a blocking object during the process of retracting or rising. The trigger detecting module30could further detect if any of the cords44has shifted away from a predetermined cord position P0, and the detection result could be used by the control module26. If the trigger detecting module30detects that at least one of the cords44has shifted away from the predetermined cord position P0, the control module26could accordingly determine whether the moving speed of the lower end12aof the covering material12has become lower than the moving speed moments ago, and whether such a situation has lasted at least for the predetermined time. Therefore, the control module26could use the detection result to determine if the covering material12has reached the fully expanded position or if it encounters resistance from a blocking object during the process of expanding or lowering. The control module26configures the motor20to stop if it determines that the covering material12is in any of the following circumstances: the covering material12has been completely retracted or raised to reach the fully retracted position, has been completely expanded or lowered to the fully expanded position, or encounters resistance during the expanding or retracting process. In some embodiments, e.g., the embodiment inFIG.4, the control module26includes a microcontroller262which further includes a processing unit2622and a memory unit2624. The memory unit2624could be realized with one or more standalone components connected to the microcontroller262, or integrated with the microcontroller262as a single component. For example, the memory unit2624may be realized with the random access memory (RAM), the read-only memory (ROM), the flash memory, the optical disc, the hard disk drive, and/or the solid-state drive to store computer-executable instructions. The processing unit2622is configured to execute the instructions to determine whether one or more trigger events are received according to the detection results of the trigger detecting module30. When the processing unit2622determines a trigger event is received, the processing unit2622configures the driving circuit28to drive the motor20accordingly. In this embodiment, the processing unit2622and the trigger detecting module30are connected through a bus59. In other embodiments, the processing unit2622could also be connected to a position detecting module52, a wireless signal receiving circuit56, and/or other components through the bus59and/or through other suitable wired/wireless connections. The functions of the position detecting module52and the wireless signal receiving circuit56will be explained in more detail below. The microcontroller may be realized with an integrated circuit component, one or more discrete circuit components, and/or the collaboration of hardware and software. The predetermined time mentioned in some embodiments could be defined in the control device24as required, e.g., configured and stored in the memory unit2624. However, it should be a sufficient period of time so that the control device24could recognize the situation when the moving speed of the lower end12aof the covering material12decreases or even becomes 0.

The following paragraphs detail the mechanism of determining if the covering material12has been fully retracted or if it encounters resistance during the process of retracting.

The trigger detecting module30includes a rotating speed detecting member32, which is adapted to measure the rotating speed of the rotating member14. In an embodiment, the rotating speed detecting member32is realized with a Hall sensor, and a magnet34is provided on the spindle142of the rotating member14as shown inFIG.3. When the spindle142rotates, the rotating speed of the spindle142could be measured by calculating the changing of the magnetic field induction between the magnet34and the rotating speed detecting member32.

A lower rotating speed limit for the rotating member14could be set in advance in the control module26, as shown inFIG.5. When the control module26configures the motor20to activate, driving the rotating member14to rotate in the first rotating direction D1for retracting the covering material12, the control module26would receive a signal of the rotating speed measured by the rotating speed detecting member32. The rotation of the rotating member14would be hindered if the covering material12has been fully retracted and the cords44cannot be further retracted by the spools144, or if the covering material12encounters resistance during the process of retracting, which prevents the cords44from being further retracted by the spools144. As a result, the rotating speed of the rotating member14would decrease, and therefore the moving speed of the lower end12aof the covering material12which is driven by the rotating member14would decrease as well. Once the rotating speed measured by the trigger detecting module30is lower than the lower rotating speed limit for the predetermined time, the control module26configures the motor20to stop. When the covering material12is fully retracted or bumps into a blocking object during the process of retracting, the control module26configures the motor20to stop rotating. If the rotating speed measured by the trigger detecting module30increases to a speed higher than the lower rotating speed limit within the predetermined time, the control module26would determine that the covering material12may encounter resistance for a brief moment. The moving speed of the lower end12aof the covering material12would not be affected by the blocking object so the covering material12would be still able to retract normally. Therefore, the control module26could, through the driving circuit28, configure the motor20to remain retracting. In an embodiment, the lower rotating speed limit is configured to be 50 percent of the original rotating speed of the motor, and the predetermined time is configured to be 100 ms to 200 ms.

In an embodiment, the magnet34could be provided on the spool144or the shaft202of the motor20. A rotating speed of the shaft202of the motor20is higher than the rotating speed of the rotating member14. When the magnet34is provided on the shaft202of the motor20, the lower rotating speed limit should be adjusted to match the rotating speed of the shaft202of the motor20. In other embodiments, the rotating speed detecting member32is provided on the shaft202of the motor20, the rotating speed detecting member32could be realized with an encoder, a resolver, and/or other suitable detecting devices capable of measuring the rotating speed of the shaft202of the motor20.

The following paragraphs detail the mechanism of determining if the covering material12has been fully expanded, or if it encounters resistance from a blocking object during the process of expanding.

As shown inFIGS.2and6-10, the trigger detecting module30further includes two trigger detecting assemblies36provided in a symmetric manner in the headrail10, each of which is respectively located near one of the spools144(e.g., as shown inFIG.2). The trigger detecting assemblies36have similar structures, e.g.,FIGS.6-7respectively illustrate the trigger detecting assemblies36located on the left side and the right side of the headrail10.

Please refer to the trigger detecting assembly36illustrated inFIGS.2,6-10. This trigger detecting assembly36includes a switch40and an elastic member38, which is realized with a torsion spring in this embodiment. The torsion spring38includes a winding portion382and two extending arms384connected to the winding portion382. An end of each of the extending arms384has a bent section384a. The winding portion382is located above the cord hole102on the left side of the headrail10, and the cord44passes through the winding portion382and the cord hole102. The winding portion382forms a restricting ring which confines the cord44therein. The switch40has an operation rod402and a main body404, wherein the switch40is electrically connected to the control module26. As shown inFIG.9, when the winding portion382of the torsion spring38is located at an original position (i.e., the cord44is at the predetermined cord position P0), the torsion spring38pushes the operation rod402to contact the main body404of the switch40.

In an embodiment, each of the trigger detecting assemblies36further includes a fixing seat42, which is fixed at the headrail10, and the torsion spring38and the switch40are provided on the fixing seat42. The fixing seat42has a receiving hole422and two narrow holes424, wherein the receiving hole422is located above the cord hole102. In a lateral direction of the headrail10, the receiving hole422is located between the two narrow holes424. The narrow holes424respectively extend in the lateral direction of the headrail10for a suitable length. The winding portion382is located in the receiving hole422, and the bent sections384aof the extending arms384are respectively received in one of the narrow holes424. When the winding portion382moves in the longitudinal direction of the headrail10, each of the bent sections384acould be correspondingly moved in the narrow hole424respectively.

As shown inFIG.9, during the process of expanding the covering material12, a lowered length of the lower end12aof the covering material12equals to the length of the cords44released due to the driving of the motor20. Each of the cords44is taut, stays at the predetermined cord position P0, and exerts a force on the respective winding portion382. The torsion spring38does not push the operation rod402to touch the main body404, and the control module26configures the motor20to operate through the driving circuit28, whereby the rotating member14could be rotated in the first rotating direction D1or the second rotating direction D2for retracting for or expanding the covering material12.

As shown inFIG.10, when the length of the cord44fully released from the spool144is longer than the lowered length of the lower end12aof the covering material12, the cord44becomes loose. When the covering material12is fully expanded and the lower end12aof the covering material12stops moving, the motor20may still drive the spools144to release the cords44for a period of time before the motor stops rotating. When the cords44are released after the lower end12aof the covering material12stops moving, the cords44become loose and leave the predetermined cord positions P0. As a result, the cord44cannot exert force on the winding portions382, and therefore the torsion spring38would return to its original position. When the torsion spring38returns to the original position, the winding portion382of the torsion spring38would push the operation rod402to touch the main body404and trigger the switches40. The switches40transit from a first state into a second state, e.g., from an open circuit state to a short circuit state. After the switches40are activated, the control module26would accordingly configure the motor20to stop. In this way, when the covering material12is fully expanded, the motor20is configured to stop automatically. When the control module26configures the motor20to rotate in a direction of retracting the covering material12, the control module26would ignore the current state of the switches40and reel in the cords44. After the cords44are reeled by the motor20to an extent that the released length of the cords44equals the expanded length of the covering material12, the cords44would move the lower end12aof the covering material12in the direction of retracting or ascending.

During the process of expanding the covering material12, if the covering material12bumps into a blocking object and the moving speed of the lower end12aof the covering material12therefore decreases, the cords44would be still released by the motor20. The moving speed of the lower end12aof the covering material12would decrease (and even stop) for a predetermined time even if the cords44are still released. If the length of the cord44released by the motor20is greater than the current expanded length of the covering material12, the cord44would become loose and does not push the torsion spring38. The torsion spring38would return to its original position, and the winding portion382would push the operation rod402to activate the switch40. As a result, the switch40would transit from a first state into a second state, e.g., from an open circuit state into a short circuit state. The control module26configures the motor20to stop if any of the switches40is activated, whereby to stop the covering material12from expanding or lowering. In this way, the covering material12could stop expanding when bumping into a blocking object during its expanding process, and therefore the covering material12or the blocking object wound not be damaged.

After the covering material12stops moving upon encountering a blocking object during its expanding, the control module26may configure the motor20to rotate in another direction for retracting or raising the covering material12. The control module26would temporarily ignore the current state of the switches40, and start to reel in the cords44. When the length of the cords44released by the driving of the motor20equals the expanded length of the covering material12, the cords44would move the lower end12aof the covering material12in the retracting direction.

Another embodiment of a trigger detecting assembly46of the present disclosure is shown inFIGS.11-12, which can be also applied in the first embodiment of the electric window covering100. The trigger detecting assembly46of this embodiment includes a switch48and a restricting ring50, wherein the switch48has an operation rod482and a main body484. The restricting ring50is connected to the operation rod482. Each of the cords44respectively passes through one of the restricting ring50. When the cord44is taut, the cord44is located at the predetermined cord position P0and exerts a force on the restricting ring50in a direction away from the switch48. The restricting ring50would pull the operation rod482, making the switch48to be in a first state (e.g., open circuit). If the lower end12aof covering material12reaches a fully expanded position or bumps into a blocking object, and such a situation lasts for a period of time, the cords44would become loose since the lengths of the cords44released by the motor20are greater than the expanded length of the covering material12. The cord44does not push the restricting ring50in the direction away from the switch48. An elastic member (not shown) inside the main body484of the switch48would drive the operation rod482to move toward the main body484for making the switch48be in a second state (e.g., short circuit). The control module26configures the motor20to stop when the switch40is in the second state. Whereby, the motor20is configured to stop when the covering material12is fully expanded or when the covering material12bumps into a blocking object during the process of expanding.

As mentioned above, the control device of the electric window covering provided in the present disclosure configures the motor to stop when the moving speed of the lower end of the covering material decreases for a predetermined time. The motor could be configured to stop the covering material from further moving in each of the following situations: when the covering material is expanded to the fully expanded position; when the covering material is retracted to the fully retracted position; or when the covering material encounters resistance during the process of expanding or retracting. With such a design, the process and components required for setting up the upper and lower limits could be reduced or even omitted. Furthermore, if the covering material bumps into a blocking object during its movement, it could be prevented from further colliding with the blocking object or getting damaged. In addition, the above-mentioned embodiments are realized with two trigger detecting assemblies. In other embodiments, the number of the trigger detecting assemblies could be configured to be one or more according to different design considerations.

In the embodiments below, an example embodiment of a control method of the electric window covering100of the present disclosure is disclosed, which would allow a user to control the movement of the covering material by interacting with the covering material, e.g., to expand, retract, or stop the covering material.

FIG.13is a schematic view of another embodiment of the control device of the present disclosure. In this embodiment, most of the components of the window covering are similar to the counterparts in the previous embodiment. The electric window covering of this embodiment further includes a position detecting module52. For example, the position detecting module52may be realized with an encoder, provided on the shaft202of the motor20and connected to the microcontroller262of the control module26. When the shaft202of the motor20rotates, the encoder may detect the revolutions of the shaft202of the motor20and generate a corresponding signal representing the number of revolutions, which is then transmitted to the control module26. When the covering material12is fully expanded, the position of the lower end12aof the covering material12is defined as a first predetermined position P1(as shown inFIG.1). When the covering material12is fully retracted, the position of the lower end12aof the covering material12is defined as a second predetermined position P2. The lower end12aof the covering material12could be moved upward to the first predetermined position P1in a first moving direction or downward to the second predetermined position P2in a second moving direction. When the lower end12aof the covering material12moves from the first predetermined position P1to the second predetermined position P2, the number of revolutions Nr of the shaft202of the motor20may be detected by the position detecting module52(e.g.,—encoder). Accordingly, the control module26may determine the position of the lower end12aof the covering material12according to a ratio between the number of revolutions Nr and another number of revolutions Nx of the shaft202of the motor20detected by the position detecting module52when the lower end12aof the covering material12moves.

In other embodiments, the position detecting module52may also be realized with one or more encoders and/or resolvers provided on the shaft202of the motor20and/or the spindle142.

As shown inFIG.4, computer-executable instructions are stored in the memory unit2624of the microcontroller262. The processing unit2622of the microcontroller262receives the detected data (e.g., the detected data generated by the trigger detecting module30and the position detecting module52) and executes the computer-executable instructions to perform the control method1400of this embodiment. The control method1400includes the following steps which are also shown inFIG.14.

Step1401: The position detecting module52detects the position of the lower end12aof the covering material12and accordingly generates a position information of the lower end12aof the covering material12.

The position detecting module52may continuously or intermittently detect the position of the lower end12aof the covering material12, or may detect the position of the lower end12aof the covering material12only when the lower end12aof the covering material12is moved or stopped. The position information may be generated in a suitable format, e.g., one or more analog waveforms and/or one or more digital messages. In an embodiment, the position detecting module52is realized with an encoder of the motor20. When the lower end12aof the covering material12stops moving, the number of revolutions of the motor20during the moving of the lower end12aof the covering material12may be detected by the encoder. The encoder generates a corresponding number of pulses as the position information. The position information may be transmitted to the processing unit2622and stored in the memory unit2624.

Step1402: The processing unit2622determines a position relationship by comparing the position information with a reference position Pa.

In the above embodiment, the position information is a number of pulses generated by the encoder of the motor20. By comparing the number of pulses generated by the encoder with a reference pulses number representing the reference position Pa, the processing unit2622determines a position relationship indicating whether the current position of the lower end12aof the covering material12is higher than the reference position Pa. When the position relationship shows the position of the lower end12aof the covering material12is higher than the reference position Pa, the processing unit2622stores a first flag in the memory unit2624. When the position relationship shows the position of the lower end12aof the covering material12is lower than the reference position Pa, the processing unit2622stores a second flag in the memory unit624. For example, the first flag and the second flag may be configured to be the same bit of a message respectively stored as 1 or 0, or configured to be different bits of a message. In this embodiment, the reference position Pa is configured to be the second predetermined position P2. In other embodiments, the reference position Pa could be configured to be a suitable position between the first predetermined position P1and the second predetermined position P2. For example, the reference position Pa may be configured to be a position above the midpoint of the first predetermined position P1and the second predetermined position P2.

Step1403: When the lower end12aof the covering material12is higher than the reference position Pa and/or the first flag is stored in the memory unit2624, the microcontroller262determines that a high-position-lifting trigger event is received when the covering material12is moved by a high-position-lifting external force.

In this embodiment, when the lower end12aof the covering material12is stopped, the trigger detecting assemblies36of the trigger detecting module30detect the condition of the cords44, and generate a high-position-lifting detecting result when the covering material12is moved by the high-position-lifting external force. For example, when the trigger detecting module30detects the cords44change from taut to loose, the trigger detecting module30generates the high-position-lifting detecting result. The microcontroller262determines the high-position-lifting trigger event is received according to the high-position-lifting detecting result. For example, the high-position-lifting trigger event may be invoked when the lower end12aof the covering material12is lifted by the high-position-lifting external force and then lowered from the lifted position.

As shown in the embodiment inFIG.15, the time diagram shows the lower end12aof the covering material12is lifted and then lowered when the lower end12aof the covering material12stops. When the lower end12aof the covering material12stops, the cords44are taut and the switches40of the trigger detecting assemblies36are in the first state. When a user lifts the lower end12aof the covering material12, the cords44become loose from taut and the switches40turn into the second state from the first state. When the user puts down the lower end12aof the covering material12, the cords44change from loose to taut and the switches40return to the first state from the second state. According to the states of the switches40, the processing unit2622determines whether the lower end12aof the covering material12is deliberately moved by the high-position-lifting external force. After turning from the first state to the second state, if the switches40stay in the second state for more than a first predetermined lifting time T1and then turn back to the first state within a predetermined lowering time T2, the processing unit2622determines the lower end12aof the covering material12is deliberately moved by the high-position-lifting external force. Accordingly, the processing unit2622determines the high-position-lifting trigger event is received. If the above timing requirements of the switch40are not met, the processing unit2622determines that the lower end12aof the covering material12is not moved by the high-position-lifting external force to invoke the high-position-lifting trigger event. For example, the lower end12aof the covering material12may be blown by the wind and hung on the furniture. The processing unit2622and the trigger detecting assemblies36of the trigger detecting module30may continuously or intermittently monitor the cords44for detecting the high-position-lifting trigger event.

In some embodiments, the first predetermined lifting time T1can be configured to a suitable interval between 0.1 and 0.5 second, and the predetermined lowering time T2can be configured to a suitable interval between 3 and 15 seconds. The first predetermined lifting time T1and the predetermined lowering time T2may also be adjusted in accordance with the current position of the lower end12aof the covering material12. Specifically, when the lower end12aof the covering material12is at positions where the change in the tension of the cords44cannot be easily detected (e.g., in regions near the first predetermined position P1or the second predetermined position P2), the first predetermined lifting time T1may be configured to be smaller. By configuring the first predetermined lifting time T1to be smaller, it is easier to meet the requirement for invoking the high-position-lifting trigger event. On the other hand, when the lower end12aof the covering material12is at positions where the change in the tension of the cords44can be easily detected, the first predetermined lifting time T1may be configured to be a little bit longer. Therefore, the sensitivity of the detecting the high-position-lifting trigger event may be adjusted to a suitable level to reduce the false alarm and unexpectedly movements of the lower end12aof the covering material12. In another embodiment, as shown inFIG.16, when the lower end12aof the covering material12is near the second predetermined position P2, the released lengths of the cords44are relatively short. Due to the limited lengths, the cords44would not easily become loose even when the lower end12aof the covering material12is lifted. Therefore, when the lower end12aof the covering material12is within a second distance L2(e.g., 2 cm) below the second predetermined position P2, the first predetermined lifting time T1can be configured to be smaller (e.g., 0.1 second), and the predetermined lowering time T2can be configured to be 10 seconds, whereby to increase the sensitivity for detecting the high-position-lifting trigger event. In another embodiment, as shown inFIG.17, when the lower end12aof the covering material12is near the first predetermined position P1, the released lengths of the cords44are relatively long. Due to the longer lengths, it takes a longer time for the trigger detecting module30to detect the cords44are loose when the lower end12aof the covering material12is lifted. Therefore, when the lower end12aof the covering material12is located within a third distance L3(e.g., 2 cm) above the first predetermined position P1, the first predetermined lift time T1can also be configured to be smaller (e.g., 0.15 second), and the predetermined lowering time T2can be configured to be 10 seconds, whereby to increase the sensitivity for detecting the high-position-lifting trigger event. In another embodiment, when the lower end12aof the covering material12is not near the predetermined positions P1and P2(e.g., away from the predetermined positions P1and P2respectively for more than the distances L3and L2), the sensitivity for detecting the high-position-lifting trigger event may be decreased. For example, the first predetermined lifting time T1can be configured to be 3 seconds, and the predetermined lowering time T2can be configured to be 10 seconds, whereby to prevent false trigger events. In another embodiment, the lengths of the second distance L2and the third distance L3can also be adjusted and/or configured to be the same or different for adjusting the sensitivity for detecting the high-position-lifting trigger event.

In this embodiment, if the switches40are turned into the second state, and are not turned back to the first state within the predetermined lowering time T2, it means that the lower end12aof the covering material12may be hindered by another object and therefore is continuously lifted, causing the cords44to stay in a loose state. In such a situation, the processing unit2622determines that the requirement for the high-position-lifting trigger event is not met even if the switches40are not turned back to the first state within the predetermined lowering time T2.

Step1404: The covering material is configured to expand according to the high-position-lifting trigger event.

In this embodiment, the microcontroller262is configured to transmit a signal to activate the motor20when determining the first high-position-lifting trigger event is received based on the high-position-lifting detecting result, e.g., according to the first flag stored in the memory unit2624. The rotating member14driven by the motor20rotates in the second rotating direction D2for moving the lower end12aof the covering material12toward the first predetermined position P1and expanding the covering material12.

Steps1405and1406: During the process of the expanding the covering material12, when the lower end12aof the covering material12is lowered to the first predetermined position P1, the lower end12aof the covering material12is configured to stop moving.

When the lower end12aof the covering material12reaches the first predetermined position P1(i.e., when the covering material12is fully expanded), the cords44may become loose from taut and the switches40may turn from the first state into the second state.

The microcontroller262receives the state changing signal of the switches40and accordingly stops the motor20from rotating. In another embodiment, when the lower end12aof the covering material12reaches the first predetermined position P1(i.e., when the covering material12is fully expanded), the cords44may become loose from taut and the switches40turn from the first state into the second state. The microcontroller262receives the state changing signal of the switches40and accordingly determines that the lower end12aof the covering material12has reached the first predetermined position P1. After the microcontroller262configures the motor20to stop rotating, the microcontroller262configures the motor20to rotate in the first rotating direction D1until the cords44become taut again, which makes the switches40turn from the second state to the first state. After the cords44become taut, the microcontroller262configures the motor20to stop rotating. The lower end12aof the covering material12can be maintained at substantially the first predetermined position P1, or moved to a position above the first predetermined position P1with a first distance L1(as shown inFIG.20). In another embodiment, the processing unit2622is configured to determine if the lower end12aof the covering material12has reached the first predetermined position P1based on the position information detected by the encoder52. When the encoder52detects the lower end12aof the covering material12reaches the first predetermined position P1, the motor20is configured to rotate in the first rotating direction D1for moving the lower end12aof the covering material12the first distance L1.

Step1407: When the lower end12aof the covering material12is lower than the reference position Pa and/or the second flag is stored in the memory unit2624, the microcontroller262determines that a low-position-lifting trigger event is received when the covering material12is moved by a low-position-lifting external force.

In this embodiment, the detections and the determinations of the low-position-lifting trigger event for the covering material12are similar to those in Step1403.

The microcontroller262transmits a signal to activate the motor20when determining the low-position-lifting trigger event is received based on a low-position-lifting detecting result and/or the second flag saved in the memory unit2624.

Step1408: The lower end12aof the covering material12is configured to retract according to the low-position-lifting trigger event.

The motor20drives the rotating member14to rotate in the first rotating direction D1for moving the lower end12aof the covering material12toward the second predetermined position P2and retracting the covering material12.

Step1409: When the lower end12aof covering material12raises to reach the second predetermined position P2during the process of retracting the covering material12, the control method1400goes to Step1406.

When the lower end12aof the covering material12reaches the second predetermined position P2(i.e., when the covering material12is fully retracted), the processing unit2622determines that the lower end12aof the covering material12has reached the second predetermined position P2according to the detecting signal of the rotating speed detecting member32, which indicates that the rotating speed of the rotating member14is lower than a lower rotating speed limit for a predetermined time. In another embodiment, the processing unit2622determines if the lower end12aof the covering material12has reached the second predetermined position P2according to the position information detected and generated by the encoder52.

Thus, the microcontroller262configures the motor20to stop rotating and the lower end12aof covering material12to stop moving (Step1406). In the processing of performing Step1403to Step1409, if the lower end12aof the covering material12stops moving, the control method1400goes back to Step1401to detect the position of the lower end12aof the covering material12, and detects whether the high-position-lifting trigger event or the low-position-lifting trigger event is received.

When the lower end12aof the covering material12does not move, the user could utilize the method1400to generate the high-position-lifting trigger event or the low-position-lifting trigger event for expanding or retracting the covering material12.

Please refer toFIG.14. The control method1400of the present disclosure can further include the features below.

Step1410: The microcontroller262determines that a lifting-while-expanding trigger event is received during the process of expanding the covering material12.

During the process of expanding the covering material12, the trigger detecting assemblies36may detect and generate a lifting-while-expanding detecting result when detecting the covering material12is lifted by a lifting-while-expanding external force and lowered. The microcontroller262determines a lifting-while-expanding trigger event is received according to the lifting-while-expanding detecting result. As shown inFIG.18, while the rotating member14is rotating in the second rotating direction D2, the microcontroller262determines that the lifting-while-expanding trigger event is received if the lifting-while-expanding detecting result shows that the lower end12aof the covering material12is lifted by an external force (i.e., the lifting-while-expanding external force) and then lowered. In this embodiment, determining the lifting-while-expanding trigger event is similar to determining the high-position-lifting trigger event in the previous embodiments. The processing unit2622determines the lifting-while-expanding trigger event is received if the switches40turn from the first state into the second state for longer than the first predetermined lifting time T1(which implies that the lower end12aof the covering material12is lifted by the user, and such a situation lasts for longer than the first predetermined lifting time T1), and then switch from the second state back to the first state within the predetermined lowering time T2(which implies that the lower end12aof the covering material12is put down by the user).

When the lifting-while-expanding trigger event is received, the control method1400goes to Step1406. The microcontroller262configures the lower end12aof the covering material12to stop and stays at its current position. Afterward, the control method1400goes back to Step1401.

FIGS.19-20collectively show another embodiment of detecting the lifting-while-expanding trigger event. After the microcontroller262stops the motor20and the rotating member14from rotating in the second rotating direction D2, the microcontroller262configures the motor20to drive the rotating member14is configured to rotate for predetermined rotations, a predetermined angle or a predetermined time in the first rotating direction D1and then stop. Thus, the cords44are retracted to move the lower end12aof the covering material12upward for a first distance L1for making sure the cords44remain taut. The predetermined rotations, the predetermined angle or the predetermined time may correspond to a predetermined number of pulses generated by the encoder52. The microcontroller262configures the motor20according to the position information detected by the encoder52for driving the rotating member14to rotate. The microcontroller262configures the motor20to stop when the position information detected by the encoder52represents the lower end12aof the covering material12has been moved upward for the first distance L1(i.e., the number of the pulses generated by the encoder52equals the predetermined number of pulses).

If the switches40turn to the second state from the first state, but do not turn back to the first state within the predetermined lowering time T2, it implies that the lower end12aof the covering material12encounters an object and therefore keeps lifted. Thus, the microcontroller262configures the motor20and therefore the rotating member14to stop from rotating. After the switches40turn back to the first state, the control method1400goes back to Step1401.

Step1411: The microcontroller262determines that a pulling-while-retracting trigger event is received during the process of retracting the covering material12.

During the process of retracting the covering material12, the rotating speed detecting member32may generate a pulling-while-retracting detecting result when detecting the covering material12is pulled by a pulling-while-retracting external force. The microcontroller262determines a pulling-while-retracting trigger event is received according to the pulling-while-retracting detecting result. The pulling-while-retracting trigger event is defined as detecting an external force (e.g., the pulling-while-retracting external force) applied against the upward movement of the lower end12aof the covering material12. An embodiment for detecting the pulling-while-retracting trigger event is shown inFIG.21, which is similar to detecting the resistance when the covering material12is moved upward in the previous embodiment. The rotating speed of the rotating member14and a predetermined stalled time are used for determining if the covering material12is pulled by the external force. The external force may be exerted by the user to stop the lower end12aof the covering material12from moving. The microcontroller262receives signals indicating the rotating speed of the rotating member14detected by the rotating speed detecting member32when the rotating member14rotates in the first rotating direction D1. If the rotating speed of the rotating member14decreases to be lower than the lower rotating speed limit for a predetermined stalled time, the processing unit2622determines that the fourth pulling-while-retracting trigger event is received, and stops the motor20and the rotating member14from rotating.

When the microcontroller262determines the pulling-while-retracting trigger event is received, the microcontroller262stops the lower end12aof the covering material12from moving (Step1406), and the control method1400goes back to Step1401.

Step1412: The microcontroller262determines that a lifting-while-retracting trigger event is received during the process of retracting the covering material12.

During the process of retracting the covering material12, the trigger detecting assemblies36may generate a lifting-while-retracting detecting result when detecting the lower end12aof the covering material12is lifted by a lifting-while-retracting external force. The microcontroller262determines a lifting-while-retracting trigger event is received according to the lifting-while-retracting detecting result.

Step1413: When the microcontroller262determines the lifting-while-retracting trigger event is received, the microcontroller262stops the lower end12aof the covering material12from moving.

Step1414: The microcontroller262determines that a lowering-while-still trigger event is received after the lower end12aof the covering material12stops moving according to the lifting-while-retracting trigger event.

After the microcontroller262determines the lifting-while-retracting trigger event is received, the trigger detecting assemblies36generate a lowering-while-still detecting result when detecting the covering material12is lowered either naturally or by the pulling of a lowering-while-still external force. The microcontroller262determines the lowering-while-still trigger event is received according to the lowering-while-still detecting result.

Step1415: When the microcontroller262determines that the lowering-while-still trigger event is received, the covering material12is configured to expand.

When the microcontroller262determines the lowering-while-still trigger event is received, the microcontroller262configures the motor20to expand the covering material12so that the lower end12aof the covering material12moves in the direction toward the first predetermined position P1for expanding the covering material12.

Step1416: When the lower end12aof the covering material12lowers to reach the first predetermined position P1, the control method1400goes to Step1406to stop the lower end12aof the covering material12from moving.

In this embodiment, the lifting-while-retracting trigger event is defined as detecting the lower end12aof the covering material12is lifted by an external force (e.g., the lifting-while-retracting external force), and the lowering-while-still trigger event is defined as detecting the lower end12aof the covering material12is lowered after it has been lifted by the lifting-while-retracting external force. An embodiment for detecting the lifting-while-retracting trigger event and the lowering-while-still trigger event is shown inFIG.22. When the rotating member14rotates in the first rotating direction D1, the cords44are taut and the switches40are in the first state. If the user lifts the lower end12aof the covering material12, the cords44becomes loose from taut and the switches40turn into the second state. The processing unit2622determines that the lifting-while-retracting trigger event is received if the switches40remain in the second state for longer than a second predetermined lifting time T3. When the processing unit2622determines that the lifting-while-retracting trigger event is received, the microcontroller262configures the motor20to stop moving the covering material12. After the user lowered the lower end12aof the covering material12, the cords44become taut from loose and the switches40return to the first state. The processing unit2622consequently determines the lowering-while-still trigger event is received. When the processing unit2622determines the lowering-while-still trigger event is received, the microcontroller262configures the motor20to drive the rotating member14to rotate in the second rotating direction D2. The lower end12aof the covering material12moves in the direction toward the first predetermined position P1for expanding the covering material12. In this embodiment, the second predetermined lifting time T3is configured to be 0.05 second. When the lower end12aof the covering material12is moved downward to reach the first predetermined position P1, the microcontroller262configures the motor20to stop moving the lower end12aof the covering material12. In another embodiment, after the lower end12aof the covering material12reaches the first predetermined position P1, the microcontroller262configures the motor20to drive the rotating member14to rotate in the first rotating direction D1for moving the lower end12aof the covering material12upward for the first distance L1. The cords44may therefore remain taut.

Step1417: The microcontroller262determines that a lifting-during-expanding trigger event is received during the process of expanding the covering material12.

During the process of expanding the covering material12according to the fifth and the lowering-while-still trigger events, the trigger detecting assemblies36generate a lifting-during-expanding detecting result when detecting the lower end12aof the covering material12is moved by a lifting-during-expanding external force. The microcontroller262determines a lifting-during-expanding trigger event is received according to the lifting-during-expanding detecting result. In this embodiment, detecting the lifting-during-expanding trigger event is similar to detecting the lifting-while-expanding trigger event, which detects whether the lower end12aof the covering material12is lifted by an external force (e.g., the lifting-during-expanding external force) and then lowered. An embodiment of the time diagram for detecting the lifting-during-expanding trigger event is shown inFIG.18and relevant description may be found above. In the embodiments, the user could maneuver the covering material12to expand, retract, or stop, and the covering material12would also stop moving when encounters an object.

When the microcontroller262determines the lifting-during-expanding trigger event is received, the control method1400goes to Step1406to stop the lower end12aof the covering material12from moving.

In Step1406, if the lower end12aof the covering material12stops moving, the control method1400goes back to Step1401to detect the position of the lower end12aof the covering material12, and detects whether the high-position-lifting trigger event or the low-position-lifting trigger event is received.

In the above embodiments, the microcontroller262determines any one of the lifting-while-expanding trigger event to the lifting-during-expanding trigger event after some of the Steps1401˜1408are executed. In other embodiments, one or more of the lifting-while-expanding trigger event to the lifting-during-expanding trigger event may also be detected and determined after the user utilizes a human-machine interface device to operate the electric window covering100. For example, after the user utilizes a wireless controller to expand the covering material12, the microcontroller may determine the lifting-while-expanding trigger event is received and configured the motor20to stop moving the lower end12aof the covering material12.

Another embodiment of the control device of the electric window covering of the present disclosure is shown inFIG.23. In this embodiment, the trigger detecting module30of the electric window covering further includes a current detector54, provided between the motor20and the driving circuit28, and electrically connected to the control module26. The current detector54detects a current of the motor20. In this embodiment, during the process of retracting the covering material12in Step1408, the microcontroller262determines whether the pulling-while-retracting trigger event is received according to an increased current of the motor20, which indicates there is an external force applied to the covering material12. As shown inFIG.24, while the rotating member14is rotating in the first rotating direction D1to retract the covering material12, the current of the motor20detected by the current detector54is normally smaller than an upper current limit. If the covering material12is pulled by an external force, the retraction of the cords44, the rotation of the rotating member14and the operation of the motor20will be consequently hindered. The current of the motor20increases accordingly. The processing unit2622determines the pulling-while-retracting trigger event is received if the current detector54detects the current of the motor20is greater than the upper current limit for longer than a predetermined stalled time T4. When the processing unit2622determines the pulling-while-retracting trigger event is received, the microcontroller262configures the motor20to stop driving the rotating member14to stop moving the lower end12aof the covering material12upward. The control method1400then goes back to Step1401. In this embodiment, the predetermined stalled time T4can be configured between 0.2-1 second.

In this embodiment, the current of the motor20, the upper current limit and the predetermined stalled time T4are used for determining whether an external force is applied when the covering material12is moved upward. Similar mechanism may also be applied to the first embodiment for determining whether the covering material12encounters resistance while it is moved upward.

Another embodiment of the control device of the electric window covering of the present disclosure is shown inFIGS.25-26. In this embodiment, the control device24includes a wireless signal receiving circuit56electrically connected to the microcontroller262of the control module26. The trigger detecting module30further includes an accelerometer58and a wireless signal transmission circuit60which are electrically connected to each other and provided in the bottom rail122at the lower end12aof the covering material12. The accelerometer58detects an acceleration of the lower end12aof the covering material12, and transmits an acceleration data through the wireless signal transmission circuit60. The microcontroller262of the control module26receives the acceleration data through the wireless signal receiving circuit56and the processing unit2622of the microcontroller262determines whether the lower end12aof the covering material12is moved (e.g., lifted or lowered) according the acceleration data.

In this embodiment, the detections of the high-position-lifting, the low-position-lifting, the lifting-while-expanding, the lifting-while-retracting, the sixth lowering-while-still, and the lifting-during-expanding trigger events may also be modified accordingly.

FIG.27illustrates a time diagram of detecting the high-position-lifting trigger event with the embodiment inFIGS.25-26. When the lower end12aof the covering material12is lifted, the value of the acceleration data detected by the accelerometer58decreases. When the lower end12aof the covering material12is lowered, the value of the acceleration data detected by the accelerometer58increases. When the acceleration data received by the microcontroller262decreases to be less than a predetermined acceleration threshold for longer than the first predetermined lifting time T1and then increases to be higher than the predetermined acceleration threshold within the predetermined lowering time T2, the processing unit2622determines the high-position-lifting trigger event is received. Similar mechanism may also be utilized for detecting the low-position-lifting trigger event, the lifting-while-expanding trigger event and the lifting-during-expanding trigger event.

FIG.28illustrates a time diagram for detecting the fifth lifting-while-retracting and the lowering-while-still trigger events. When the lower end12aof the covering material12is lifted, the acceleration data detected by the accelerometer58decreases. When the acceleration data received by the microcontroller262decreases to be less than the predetermined acceleration threshold for longer than the second predetermined lifting time T3during the process of retracting the covering material12, the processing unit2622determines the lifting-while-retracting trigger event is received. If the lifting-while-retracting trigger event is received, the microcontroller262stops the motor20from retracting the lower end12aof the covering material12. After receiving the lifting-while-retracting trigger event, if the received acceleration data increases to be higher than the predetermined acceleration threshold (i.e., the lower end12aof the covering material12is lowered), the processing unit2622determines the lowering-while-still trigger event is received. If the microcontroller262determines the lowering-while-still trigger event is received, the microcontroller262configures the motor20to move the lower end12aof the covering material12downward for expanding the covering material.

FIG.29shows another embodiment of the trigger detecting module30, which includes a piezoelectric component62and a wireless signal transmission circuit60electrically connected to each other. The piezoelectric component62is provided at a bottom of the bottom rail122, and the wireless signal transmission circuit60is provided in the bottom rail122. If the bottom rail122is lifted by a user, the piezoelectric component62detects an upward force and change the output voltage of the piezoelectric component62. The output voltage of the piezoelectric component62is transmitted through the wireless signal transmission circuit60. After the microcontroller262receives the output voltage of the piezoelectric component62through the wireless signal receiving circuit56, the processing unit2622of the microcontroller262determines if the lower end12aof the covering material12is moved by an external force (e.g., lifted or lowered) according to the output voltage of the piezoelectric component62. In this embodiment, the output voltage of the piezoelectric component62is configured to be proportional to the pressure exerted on the piezoelectric component62.

In this embodiment, the detections of the high-position-lifting, the low-position-lifting, the lifting-while-expanding, the lifting-while-retracting, the lowering-while-still, and the lifting-during-expanding trigger events are modified accordingly.

FIG.30illustrates a time diagram for detecting the high-position-lifting trigger event. When the lower end12aof the covering material12is lifted, the output voltage generated by the piezoelectric component62increases. When the lower end12aof the covering material12is lowered, the output voltage generated by the piezoelectric component62decreases. When the output voltage of the piezoelectric component62received by the microcontroller262increases to be higher than or equal to a predetermined voltage threshold for longer than the first predetermined lifting time T1and then decreases to be less than the determined voltage threshold within the predetermined lowering time T2, the processing unit2622determines the high-position-lifting trigger event is received. Similar mechanism may also be utilized for detecting the low-position-lifting trigger event, the lifting-while-expanding trigger event and the lifting-during-expanding trigger event.

FIG.31illustrates a time diagram for detecting the lifting-while-retracting and the lowering-while-still trigger events. When the lower end12aof the covering material12is lifted, the output voltage generated by the piezoelectric component62increases to be greater than or equal to the predetermined voltage threshold. When the output voltage of the piezoelectric component62received by the microcontroller262is greater than or equal to the predetermined voltage threshold for longer than the second predetermined lifting time T3during the process of retracting the covering material12, the processing unit2622determines the lifting-while-retracting trigger event is received. If the lifting-while-retracting trigger event is received, the microcontroller262stops the motor20from retracting the lower end12aof the covering material12. After receiving the lifting-while-retracting trigger event, if the output voltage of the piezoelectric component62received by the microcontroller262decreases to be less than the predetermined voltage threshold (i.e., the lower end12aof the covering material12is lowered), the processing unit2622determines the lowering-while-still trigger event is received. If the lowering-while-still trigger event is received, the microcontroller262configures the motor20to move the lower end12aof the covering material12downward for expanding the covering material12.

In another embodiment, the output voltage of the piezoelectric component62may also be configured to be inversely proportional to the pressure exerted on the piezoelectric component62. When the lower end12aof the covering material12is lifted, the output voltage generated by the piezoelectric component62decreases. Afterward, when the lower end12aof the covering material12is lowered, the output voltage generated by the piezoelectric component62increases. The detections and the determinations of the trigger events may also be adjusted accordingly.

In addition to the aforementioned switches40, accelerometer58, and piezoelectric component62, other means can also be utilized as detecting module to detect the lower end12aof the covering material12, such as an electrostatic sensor, a capacitive sensor, a gyroscope, a vibration sensor, a sound sensor, and an ultrasonic wave sensor. When the lower end12aof the covering material12is lifted or lowered, the microcontroller262of the control module26determines whether one or more trigger events are received according to the output signals of the detecting means.

Therefore, the above control method enables the user to expand, retract, or stop the covering material by [via] manipulating the covering material without the human-machine interface device (e.g., wired or wireless controllers), which would be more convenient in use.

In another embodiment, when the lower end12aof the covering material12of the electric window covering encounters an external object, the microcontroller262of the present disclosure may cope with this situation with some modifications. When the detecting module (e.g., one or more of the trigger detecting module30, position detecting module52, switches40, accelerometer58, and piezoelectric component62) detects the lower end12aof the covering material12moves in the first moving direction and encounters resistance, the microcontroller262may configure the motor20to rotate reversely instead of stopping the driving device16. The lower end12aof the covering material12is moved in the second moving direction, which is different from the first moving direction. For example, if the driving device16originally rotates in the second rotating direction D2and the microcontroller262configures the driving device16to rotate reversely, the microcontroller262configures the driving device16to stop and then rotate in the first rotating direction D1. In the process of configuring the driving device16to rotate reversely, the microcontroller262may explicitly configure the driving device16to rotate in a first rotating direction, stop for a human noticeable duration, and then rotate in a second rotating direction. In another embodiment, the microcontroller262may also configure the driving device16to operate as if the driving device16changes the rotating direction without a halt. There is, however, at least a small amount of time, even if human-unnoticeable, in which the rotating speed of the driving device16approaches zero and behaves like being stopped. Whether the duration of time that the driving device16remains stopped is noticeable by human or not, when referring to the process of rotating the driving device16reversely, the driving device16is considered to stop from rotating in a previous rotating direction and then rotate in the other direction. Accordingly, the lower end12aof the covering material12is considered to stop from a previous moving direction and then move in the other direction. In the following embodiments, the first moving direction of the lower end12aof the covering material12is downward, and the second moving direction is upward. However, the orders of the moving directions are not limitations of the present disclosure.

When the lower end12aof the covering material12moves downward and encounters resistance, the cords44may become loose and tangled, and therefore fail to function properly anymore. In another embodiment, as shown inFIG.32, when the detecting module detects the lower end12aof the covering material12moves downward and encounters resistance from an external object O, the microcontroller262configures the driving device16to rotate reversely. Thus, a suitable length of the cords44may be reeled in to the spools144, and the cords44may remain taut. The tangle of the cords44and the consequent malfunction can be prevented. The reeled-in length of the cords44may be configured to be a predetermined length, a length determined by rotating the driving device16for a predetermined return time, or dynamically determined by the microcontroller262to decide if the reeled-in length is sufficient to make the cords44become taut again, whereby to move the lower end12aof the covering material12upward for a return distance DS. For example, in the process of rotating the driving device16reversely, once the state of the switches40change to indicate that the cords44are taut, the microcontroller262accordingly configures the driving device16to stop rotating reversely.

Moreover, the microcontroller262may also calculate the position of the lower end12aof the covering material12according to the output signal(s) of the components such as the rotating speed detecting member32, the encoder52, and/or the resolver. The output signals of the encoder52and the resolver (not shown) can be configured to represent the rotating direction, the rotating speed, the rotating time, and/or the rotating distance of the rotating member14and/or the driving device16. In addition, the rotating speed detecting member32can be also configured to detect the rotating direction and the rotating speed of the rotating member14and/or the driving device16according to information such as the rotating speed(s) of the spindle142, the spool144and/or the output shaft202of the motor20. The microcontroller262would be able to calculate the length of the cords44released from the headrail10based on the rotating direction, the rotating speed, and the rotating time of the rotating member14and/or the driving device16according to the output signal(s) of the rotating speed detecting member32and/or other component(s) (e.g., an encoder, a resolver, and/or a memory unit2624). In addition to the released length of the cords44, the microcontroller262also has the knowledge of the second predetermined position P2and/or the first predetermined position P1of the covering material12, and therefore can calculate the position of the lower end12aof the covering material12.

In another embodiment, when the lower end12aof the covering material12encounters resistance from an external object O, according to the position of the lower end12aof the covering material12, different problems may happen and require different solutions. The microcontroller262may further configure the driving device16to rotate reversely for moving the lower end12aof the covering material12for different distances in response to various scenarios. For example, the first predetermined position P1of the lower end12aof the covering material12may be configured to be a position where the lower end12aof the covering material12touches or approaches a reference surface R. The reference surface R may be configured to be a sill, a floor, a ground, or other suitable horizontal levels (which may be a tilt and/or uneven surface). In this embodiment, if the window covering is not properly installed, the cords44or the spool144ages, and/or there are items (e.g., shoes, books and toys) situated near the first predetermined position P1, the lower end12aof the covering material12would not be able to move to the first predetermined position P1when encounters resistance in the vicinity of the reference surface R. In such circumstances, the cords44cannot become loose to a larger extent. In this situation, the possibility of the cords44getting tangled is lower, and reeling in a smaller length of the cords44for moving the lower end12aof the covering material12in the reverse direction for a smaller distance may suffice. Whereas, when the lower end12aof the covering material12encounters an external object O at a distance away from the reference surface R, there is more room for the cords44to loosen and the probability of tangling the cords44is higher. It may be better to reel in a greater length of the cords44for moving the lower end12aof the covering material12for a greater distance to prevent the tangle of the cords44. In the above embodiment, the reference surface R is configured to be a physical position in the real world. In other embodiments, the position of the reference surface R may be configured according to the upper limit (the second predetermined position P2) of the covering material12, the lower limit (the first predetermined position P1) of the covering material12, the position of the headrail10, and/or the output of the rotating speed detecting member32. The microcontroller262may therefore configure the driving device16to rotate, stop and rotate reversely according to the position of the reference surface R. For example, the control module26may configure the reference surface R to be the position where the lower end12aof the covering material12reaches after the driving device16rotating for a predetermined time (for example, 15 seconds) for releasing the lower end12aof the covering material12from the position of the headrail10. In another embodiment, the control device24may be configured to have multiple reference surfaces.

Moreover, since the covering material12may be elastic or stretchable to some degree, it might not be easy to precisely detect the distance when the microcontroller262configures the lower end12aof the covering material12to move. Therefore, in another embodiment, when the microcontroller262configures the lower end12aof the covering material12to move, the return distance DS of the covering material12may be configured according to the length of the cords44to be reeled in by the driving device16.

In another embodiment, as shown inFIG.33, when the lower end12aof the covering material12encounters an external object O within a predetermined proximity distance DN measured from the reference surface R, the microcontroller262correspondingly configures the driving device16to reel in the cords44for a first length for moving the lower end12aof the covering material12upward for a first return distance DS1, whereby to prevent the cords44from tangling. On the other hand, as shown inFIG.34, when the lower end12aof the covering material12encounters an external object O at a position out of the predetermined proximity distance DN measured from the reference surface R, the microcontroller262configures the driving device16to reel in the cords44for a second length for moving the lower end12aof the covering material12upward for a second return distance DS2, whereby to prevent the cords44from tangling. In this embodiment, the first length is configured to be smaller than the second length, so that the first return distance DS1is smaller than the second return distance DS2. Moreover, the first length may also be configured to be greater than or equal to the second length for meeting different design requirements, so that the first return distance DS1is greater than or equal to the second return distance DS2. In another embodiment, the first length is configured to be greater than the second length for solving another problem. When the lower end12aof the covering material12encounters the external object O at a position out of the predetermined proximity distance measured from the reference surface R, the microcontroller262correspondingly configures the driving device16to reel in the cords44for the second length for moving the lower end12aof the covering material12upward for a shorter second return distance DS2. In this embodiment, the reference surface R and/or the predetermined proximity distance DN may be respectively configured to be different from the counterparts in the previous embodiment. The shorter second return distance DS2may prevent the lower end12aof the covering material12from bumping into the headrail10, whereby to avoid unnecessary reactions and/or damages of the components of the electric window covering. For example, the power consumption may be lowered for not executing unnecessary operations which may take place when the lower end12aof the covering material12and the headrail10squeeze the covering material12. Moreover, the microcontroller262may configure the driving device16to reel in the cords44for moving the lower end12aof the covering material12upward for a same return distance DS wherever it encounters the external object O. In another embodiment, the microcontroller262may also configure the driving device16to reel in the cords44for moving the lower end12aof the covering material12for a return distance DS which is to be determined depending on the predetermined proximity distance DN between the reference surface R and the position where the lower end12aof the covering material12encounters the external object O. For example, if the lower end12aof the covering material12encounters an external object O in the vicinity of the reference surface R and the headrail10, the microcontroller262configures the driving device16to reel in the cords44for moving the lower end12aof the covering material12upward for a shorter return distance DS. On the contrary, if the lower end12aof the covering material12encounters the external object O out of the vicinity of the reference surface R, the microcontroller262configures the driving device16to reel in the cords44for moving the lower end12aof the covering material12upward for one or more greater return distances DS.

Moreover, if the microcontroller262configures the driving device16to move the lower end12aof the covering material12upward too much, a gap may be left or widened in the vicinity of the reference surface R, allowing light to pass through and bothering the user. In another embodiment, when the lower end12aof the covering material12encounters an external object O in the vicinity of the reference surface R, the microcontroller262configures the driving device16to move the lower end12aof the covering material12upward for a short return distance DS and determine whether the switches40have been changed to a first state indicating that the cords44are taut. By iterating the operations of moving the lower end12aof the covering material12upward for a short return distance DS and determining whether the cords44are taut, the microcontroller262could stop the reverse rotation of the driving device16shortly after the switches40change to the first state indicating that the cords44are taunt or after a predetermined number of iterations are executed. Therefore, the gap formed between the lower end12aof the covering material12and the reference surface R may be eliminated or narrowed.

Moreover, if the lower end12aof the covering material12moves at a high speed when encounters an external object O, the rotating speed of the rotating member is high and a large amount of the cords44may become loose. The possibility that the cords44get tangled and malfunctioned may therefore be higher. In another embodiment, the microcontroller262configures the driving device16to move the lower end12aof the covering material12for different return distances DS according to different rotating speed of the driving device16and/or the rotating member14(for example, the return distances DS can be determined according to a predetermined rotating speed, a custom defined rotating speed, and/or output signals from components such as the rotating speed detecting member32, the encoder52, and/or the resolver). When the rotating speed of the driving device16and/or the rotating member14is lower than a predetermined speed threshold so that the lower end12aof the covering material12moves downward with a first speed until bumping into the external object O, the microcontroller262configures the driving device16to reel in the cords44for a third length for moving the lower end12aof the covering material12upward for a third return distance to prevent the cords44from tangling. When the rotating speed of the driving device16and/or the rotating member14is higher than the predetermined speed threshold so that the lower end12aof the covering material12moves downward with a second speed until bumping into the external object O, the microcontroller262configures the driving device16to reel in the cords44for a fourth length for moving the lower end12aof the covering material12upward for a fourth return distance to prevent cords44from tangling, wherein the first speed is lower than the second speed. In this embodiment, the third length is configured to be smaller than the fourth length, so that the third return distance is smaller than the fourth return distance. In another embodiment, the third length may also be configured to be greater than or equal to the fourth length for meeting different design requirements, and the third return distance is greater than or equal to the fourth return distance. Moreover, in other embodiments, when the lower end12aof the covering material12bumps into an external object O during its downward movement, the microcontroller262can also configure the lower end12aof the covering material12to move upward for the same return distance DS no matter which speed the lower end12aof the covering material12moves at. In another embodiment, the microcontroller262may also configure the driving device16to reel in the cords44for moving the lower end12aof the covering material12upward for a return distance DS which is to be determined according to the rotating speed of the driving device16and/or the rotating member14. In addition, there can be multiple different predetermined speed thresholds configured in advance, which correspond to different upward return distances, respectively.

Moreover, the above embodiments may be properly combined to accommodate different scenarios, whereby to use various operation modes to move the lower end12aof the covering material12. For example, when the lower end12aof the covering material12encounters an external object O, the microcontroller262can, based on different criteria, configure the driving device16with a first operation mode to move the lower end12aof the covering material12in another direction, or configure the driving device16with a second operation mode to stop the driving device16so that the lower end12aof the covering material12stops moving. In another embodiment, when the lower end12aof the covering material12moves downward and encounters an external object O at a position out of a predetermined proximity distance DN measured from the reference surface R, the microcontroller262configures the driving device16to operate in the first operation mode which moves the lower end12aof the covering material12upward for a proper return distance DS. When the lower end12aof the covering material12encounters an external object O at a position within the predetermined proximity distance DN measured from the reference surface R, the microcontroller262configures the driving device16to operate in the second operation mode which stops the driving device16without making it rotate reversely, so that the lower end12aof the covering material12stops moving. In another embodiment, when the lower end12aof the covering material12encounters an external object O within the predetermined proximity distance DS measured from the reference surface R, the microcontroller262configures the driving device16to operate in the first operation mode, whereby to move the lower end12aof the covering material12upward for an appropriate return distance DS. When the lower end12aof the covering material12moved downward and bumps into an external object O at a position out of the predetermined proximity distance DN measured from the reference surface R, the microcontroller262configures the driving device16to operate in the second operation mode, whereby to stop the driving device16without making it rotate reversely. In addition, the microcontroller262can also operate in the first operation mode to configure the driving device16to move the lower end12aof the covering material12in a reverse direction for different distances based on different conditions. In another embodiment, when the lower end12aof the covering material moves downward and encounters an external object O at a position within the predetermined proximity distance DN measured from the reference surface R, the microcontroller262configures the driving device16to reel in the cords44for a fifth length for moving the lower end12aof the covering material12upward for a shorter fifth return distance. When the lower end12aof the covering material12encounters an external object O at a position out of the predetermined proximity distance DN measured from the reference surface R, the microcontroller262configures the driving device16to reel in the cords44for different lengths according to the different moving speeds of the lower end12aof the covering material12. For example, when the lower end12aof the covering material12is moved at a first speed, the cords44will be reeled in for a sixth length. When the lower end12aof the covering material12is moved at a second speed, the cords44will be reeled in for a seventh length L7, wherein the sixth length is different from the seventh length. The sixth length can be configured to be smaller than the seventh length, so that the lower end12aof the covering material12can be moved upward for different distances, i.e., the sixth return distance and the seventh return distance. Moreover, the sixth length and the seventh length are both greater than the fifth length, and the sixth return distance and the seventh return distance are both greater than the fifth return distance. In another embodiment, the sixth length can be configured to be greater than the seventh length. In another embodiment, when the lower end12aof the covering material12encounters an external object O and the rotating speed of the driving device16and/or the rotating member14is higher than the predetermined speed threshold, the microcontroller262configures the driving device16to operate in the first operation mode to move the lower end12aof the covering material12in another direction. Whereas when the lower end12aof the covering material12encounters an external object O and the rotating speeds of the driving device16and/or the rotating member14is lower than the predetermined speed threshold, the microcontroller262configures the driving device16to operate in the second operation mode which stops the driving device16from rotating, so that the lower end12aof the covering material12stops moving

In the above descriptions, the first to the seventh lengths are merely examples of the lengths that the lower end12aof the covering material12is moved backward when encounters the external object O. Similarly, the first to the seventh return distances are merely examples of the return distances DS that the lower end12aof the covering material12is moved in another moving direction when encounters the external object O. The ordinal number of the aforementioned first to seventh lengths/return distances is for illustrative purposes and not referring to their order or value, which should not be deemed as the limitations of the present disclosure.

In the drawings, the motor20and the decelerator22of the driving device16are respectively drawn as separated elements for the purposes of conciseness and clear explanation. In the above embodiments, the driving device16may also include more than one motor and/or more than one decelerator. For example, when the microcontroller262configures the driving device16to drive the rotating member14in the first rotating direction D1, the motor20and a first decelerator (not shown in the figures) may be used to drive the rotating member14in the first rotating direction D1. Whereas, when the microcontroller262configures the driving device16to drive the rotating member14in the second rotating direction D2, the motor20and a second decelerator (not shown in the figures) may be used to drive the rotating member14in the second rotating direction D2. In another embodiment, when the microcontroller262configures the driving device16to drive the rotating member14in the first rotating direction D1, a first motor (not shown in the figures) and the decelerator22may be used to drive the rotating member14in the first rotating direction D1. Whereas, when the microcontroller262configures the driving device16to drive the rotating member14in the second rotating direction D2, a second motor (not shown in the figures) and the decelerator22may be used to drive the rotating member14in the second rotating direction D2. In another embodiment, when the microcontroller262configures the driving device16to drive the rotating member14in the first rotating direction D1, the first motor and the first decelerator may be used to drive the rotating member14in the first rotating direction D1. Whereas, when the microcontroller262configures the driving device16to drive the rotating member14in the second rotating direction D2, the second motor and the second decelerator may be used to drive the rotating member14in the second rotating direction D2.

In the above embodiments, when referring to a component A is connected to a component B, the two components may be directly or indirectly connected mechanically, structurally, electrically, or in other suitable manners as described in the context.

The above descriptions are only some possible embodiments of the present disclosure. All equivalent structures and methods which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present disclosure.