RADIO-FREQUENCY CONTROLLED MOTORIZED ROLLER SHADE

• US 20070273309A1
• Filed: 05/22/2007
• Published: 11/29/2007
• Est. Priority Date: 05/23/2006
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Electronics Company Incorporated (Lutron Electronics)
• Inventors: Carmen, Lawrence R.
• Granted Patent: US 7,723,939 B2
• Time in Patent Office: Days
• US Class Current: 318/16
• CPC Class Codes: E06B 9/40 Roller blinds usable only as awnings E04F10/06
• CPC Class Codes: H02K 11/0141 Shields associated with casings, enclosures or brackets

Abstract

A roller shade structure controlled by radio-frequency (RF) wireless communication from a control device comprises a roller tube and a conductive enclosure. The conductive enclosure is mounted inside the roller tube for enclosing a motor drive system having a motor operable to controllably rotate the roller tube in a direction at a speed when a voltage is applied to the motor. A capacitive coupling is provided between the enclosure and the roller tube, the capacitive coupling providing an increased signal strength of RF signals received by the RF receiver.

Claims

1. A roller shade structure controlled by radio-frequency (RF) wireless communication from a control device, the structure comprising:

a roller tube; and

a conductive enclosure mounted inside the roller tube for enclosing a motor drive system having a motor operable to controllably rotate the roller tube in a direction at a speed when a voltage is applied to the motor;

wherein a capacitive coupling is provided between the enclosure and the roller tube, the capacitive coupling providing an increased signal strength of RF signals received by the RF receiver.

2. The structure of claim 1, wherein the motor drive system comprises:

a direct-current motor coupled to be driven by a Half-bridge motor drive circuit;

a microcontroller coupled to control the motor drive circuit;

a Hall effect sensor circuit coupled to provide motor position signals to the microcontroller;

a memory coupled to the microcontroller;

an RF receiver coupled to the microcontroller; and

a switching power supply coupled to supply power to the microcontroller and the motor drive circuit.

3. The structure of claim 1, wherein the motor drive system is mounted on a printed circuit board (PCB) having a circuit common, the PCB being housed inside the enclosure, the circuit common being electrically connected to the enclosure.

4. The structure of claim 3, wherein the enclosure includes first and second halves that are manufactured from a conductive material.

5. The structure of claim 3, wherein the enclosure includes clamps adapted to electrically connect the circuit common to the enclosure.

6. The structure of claim 5, further comprising an antenna extending exteriorally of the roller shade structure.

7. The structure of claim 6, wherein the antenna comprises an insulated wire portion and a coaxial cable portion coupled to a connector mounted on the PCB, the coaxial cable portion extending from exteriorally of the roller shade structure to the connector.

8. The structure of claim 7, wherein the antenna further comprises a coaxial PCB portion including a plurality of layers, the coaxial PCB portion extending from the connector to the RF transceiver.

9. The structure of claim 8, wherein the coaxial PCB portion includes top and bottom ground plane layers connected to the circuit common, and a middle layer including a signal trace surrounded by two ground planes, the two ground planes connected to the circuit common.

10. The structure of claim 2, wherein the motor drive system further comprises a bearing coupled to the roller tube and to an output shaft connected to the motor through a gear mechanism, wherein the motor drive system rotates the roller tube through the output shaft and the bearing.

11. The structure of claim 2, wherein the capacitive coupling has a capacitance of approximately 350 pF.

13. The roller shade structure of claim 11, wherein the roller tube and the enclosure are capacitively coupled.

15. The roller shade structure of claim 13, wherein the roller tube is metal.

16. The roller shade structure of claim 13, wherein the roller tube is coated with an electrically conductive material.

17. The roller shade structure of claim 15, wherein the roller tube is electrically insulating.

18. The roller shade structure of claim 11, wherein the enclosure is coupled to the circuit common of the circuit board.

19. The roller shade structure of claim 11, wherein the antenna comprises a length of coaxial cable having a shield.

20. The roller shade structure of claim 18, wherein a portion of the shield of the coaxial cable is removed.

12. A roller shade structure comprising:

a roller tube for winding the shade;

a motor inside the roller coupled to the roller tube for driving the roller tube in rotation;

a circuit board attached to the motor having a motor drive circuit thereon and a filter circuit for reducing RF noise generated by the motor drive circuit and the motor, the circuit board further having an RF receiver thereon for receiving RF control signals for controlling the motor;

an antenna coupled to the RF receiver for providing the control signals to the receiver, the antenna extending from the roller tube; and

an electrically conductive enclosure for the motor and circuit board;

wherein the roller tube and the enclosure are electrically coupled by a low impedance at the RF frequency of the control signals.

14. The roller shade structure of claim 12, wherein the capacitive coupling is obtained by making the roller tube electrically conductive.