Motorized window treatment

Patent metadata

Field	Value
Publication number	US-9810020-B2
Application number	US-201514690914-A
Country	US
Kind code	B2
Filing date	Apr 20, 2015
Priority date	Mar 11, 2011
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A motorized window treatment may provide a low-cost solution for controlling the amount of daylight entering a space through a window. The window treatment may include a covering material (e.g., a cellular shade fabric or a roller shade fabric), a drive assembly for raising and lowering the covering material, and a motor drive unit including a motor configured to drive the drive assembly to raise and lower the covering material. The motorized window treatment may comprise one or more battery packs configured to receive batteries for powering the motor drive unit. The batteries may be located out of view of a user of the motorized window treatment (e.g., in a headrail or in a battery compartment). The motorized window treatment may use various power-saving methods to lengthen the lifetime of the batteries, e.g., to reduce the motor speed to conserve additional battery power and extend the lifetime of the batteries.

First claim

What is claimed is:

1. A motorized window treatment comprising:
a covering material;
a drive assembly configured to raise and lower the covering material;
a motor drive unit including a motor configured to drive the drive assembly to raise and lower the covering material between a fully-open position and a fully-closed position and to any position intermediate the fully-open and fully-closed positions; and
at least one battery pack configured to hold at least one battery for producing a battery voltage to power the motor drive unit;
wherein the motor drive unit is configured to monitor the magnitude of the battery voltage, the motor drive unit further configured to operate the motor at a reduced motor speed in response to the state of charge being reduced below a first predetermined threshold.

2. The motorized window treatment of claim 1 , wherein the motor drive unit comprises a motor and a controller configured to rotate the motor to adjust the position of the covering material.

3. The motorized window treatment of claim 2 , wherein the motor drive unit further comprises a transistor-bridge drive circuit, the controller configured to provide a pulse width modulated (PWM) control signal to the drive circuit for driving the motor to control the rotational speed of the motor so as to cause the transistor-bridge drive circuit to conduct a pulse-width modulated load current.

4. The motorized window treatment of claim 3 , further comprising:
a filter circuit having an input electrically coupled to the battery-powered supply to receive the battery voltage, and an output electrically coupled to the transistor-bridge circuit to conduct the pulse-width modulated load current;
wherein the filter circuit is configured to conduct a substantially DC battery current from the battery-powered supply.

5. The motorized window treatment of claim 3 , wherein the controller is configured to ramp the rotational speed up from zero to a desired rotational speed across a ramp time when starting the motor from a stopped condition.

6. The motorized window treatment of claim 3 , wherein the controller is configured to increase the duty cycle of the PWM control signal as the covering material is raised from the midway position to the fully-open position and when the covering material is lowered from the midway position to the fully-closed position.

7. The motorized window treatment of claim 3 , further comprising:
a power supply for receiving the battery voltage and generating a DC supply voltage having a first nominal magnitude for powering the controller;
wherein the controller is configured to increase the magnitude of the DC supply voltage to a second increased magnitude greater than the first magnitude when the controller is driving the motor drive circuit to raise and lower the covering material.

8. The motorized window treatment of claim 2 , wherein the motor drive unit further comprises a rotational position sensor to enable the motor drive unit to sense movement of an output shaft of the motor, the controller configured to determine the position of a bottom end of the covering material in response to the rotational position sensor.

9. The motorized window treatment of claim 8 , wherein the covering material is engageable by a user to manually adjust the covering material, the controller configured to determine the position of the covering material in response to the covering material being manually adjusted.

10. The motorized window treatment of claim 9 , wherein the motor produces an electromotive force when the covering material is manually adjusted, the electromotive force being coupled to an input of the controller, the controller having a sleep mode and an active mode, the controller changing from the sleep mode to the active mode in response to the controller input receiving the electromotive force and allowing the controller to receive and process a sensor signal received from the rotational position sensor to determine the position of the bottom end of the covering material if the covering material is manually adjusted.

11. The motorized window treatment of claim 8 , further comprising:
a supplemental power source configured to power the controller; and
a memory configured to store data related to the determined position to prevent loss of the position data it the at least one battery is removed from the battery pack.

12. The motorized window treatment of claim 2 , wherein the controller is configured to begin operating in a first low-battery mode in response to the magnitude of the battery voltage dropping below the first predetermined low-battery threshold, the controller configured to operate the motor at the reduced motor speed in the first low-battery mode;
wherein the controller is configured to begin operating in a second low battery mode in response to the magnitude of the battery voltage dropping below the first predetermined low-battery threshold a second time, the controller configured to stop the rotation of the motor in the second low-battery mode; and
wherein the controller is configured to begin operating in a third low-battery mode in response to the magnitude of the battery voltage dropping below the first predetermined low-battery threshold a third time, the controller configured to shut down in the third low-battery mode so that approximately no current is drawn from the battery-powered supply.

13. The motorized window treatment of claim 2 , wherein the controller is configured to determine if the magnitude of the battery voltage is below a second predetermined threshold less than the first predetermined threshold, the motor drive unit configured to prevent movements of the covering material except to allow for one additional movement of the covering material to the fully-open position if the magnitude of the battery voltage has dropped below the second predetermined threshold.

14. The motorized window treatment of claim 1 , wherein the motor drive unit is configured to prevent the motor from operating to lower the covering material until an upper limit for the covering material is reset after a loss of power.

15. The motorized window treatment of claim 1 , wherein the at least one battery pack comprises first and second battery packs, each battery pack comprising a plurality of batteries electrically coupled in series.

16. The motorized window treatment of claim 15 , further comprising:
a battery-balancing circuit electrically coupled to the first and second battery packs;
wherein a series combination of a first diode and the batteries of the first battery pack is electrically coupled in parallel with a series combination of a second diode and the batteries of the second battery pack so as to generate a battery voltage at an output of the battery-balancing circuit.

17. The motorized window treatment of claim 16 , wherein the battery-balancing circuit comprises the first diode electrically coupled in series with the series-coupled batteries of the first battery pack and the second diode electrically coupled in series with the series-coupled batteries of the second battery pack, the cathodes of the first and second diodes electrically coupled together to produce the battery voltage at the junction of the first and second diodes.

18. The motorized window treatment of claim 17 , wherein the junction of the first and second diodes and a common reference of the battery packs are electrically coupled to the motor drive unit via two respective electrical wires, the motorized window treatment further comprising:
a wire antenna for receiving RF sign

Assignees

• Lutron Electronics Co

Inventors

• Adams Jason O
• Blair Edward J
• Cooney Andrew Karl
• Jain Soumya
• Kirby David A
• Lundy Stephen
• Mierta Justin J
• Mistarz Daniel W
• Newman Jr Robert C
• Ogden Jr Peter W
• Roe Jonathan L
• Wu Chen Ming
• Zernhelt Justin M
• Chambers Samuel F

Classifications

• E06B2009/6809

  Control · CPC title

• E06B9/322

  Details of operating devices, e.g. pulleys, brakes, spring drums, drives ({operating devices E06B9/68} ; devices of general interest specially adapted or mounted for storing and repeatedly paying-out and re-storing lengths of material B65H75/34) · CPC title

• E06B9/32

  Operating, guiding, or securing devices therefor (operation of tilting bars E06B9/307) · CPC title

• E06B2009/2625

  Pleated screens, e.g. concertina- or accordion-like · CPC title

• E06B2009/6872

  using counters to determine shutter position · CPC title