Touch screen having a uniform actuation force and a maximum active area

• US 20070290628A1
• Filed: 06/20/2006
• Published: 12/20/2007
• Est. Priority Date: 06/20/2006
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Electronics Company Incorporated (Lutron Electronics)
• Inventors: Altonen, Gregory, Spira, Joel S.
• Granted Patent: US 7,566,995 B2
• Time in Patent Office: Days
• US Class Current: 315/291
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: H03K 17/96 Touch switches specially adapted for electronic time-pieces with no moving parts G04G21/08
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: H05B 47/165 following a pre-assigned programmed sequence; Logic control [LC]
• CPC Class Codes: H05B 47/17 Operational modes, e.g. switching from manual to automatic mode or prohibiting specific operations

Abstract

A load control device for controlling the amount of power delivered to an electrical load from an AC power source comprises a touch sensitive device having a touch sensitive front surface responsive to a point actuation. The front surface is adapted to be provided in an opening of a faceplate such that the front surface of the touch sensitive actuator extends through the opening at a distance equal to or greater than the depth of the faceplate. According to the present invention, the operational area of the front surface is maximized to substantially the entire area of the front surface. Further, a minimum magnitude of a force of each of the point actuations is substantially equal at each of the respective positions on the front surface of the touch sensitive actuator, such that the front surface provides a substantially uniform force profile.

Claims

1. A load control device for controlling the amount of power delivered to an electrical load from an AC power source, the load control device comprising:

a controllably conductive device operable to be coupled in series electrical connection between the source and the load, the controllably conductive device having a control input for controlling the controllably conductive device between a non-conductive state and a conductive state;

a controller operatively coupled to the control input of the controllably conductive device for controlling the controllably conductive device between the non-conductive state and the conductive state;

a touch sensitive front surface adapted to be provided in an opening of a faceplate, such that the touch sensitive front surface is provided either substantially coextensive with the opening of the faceplate or slightly beyond a front surface of the faceplate; and

a touch sensitive device responsive to a plurality of point actuations on the touch sensitive front surface, each point actuation characterized by a position and a force,

the touch sensitive device having an output operatively coupled to the controller for providing a control signal representative of the position of the point actuation and responsive to the point actuation when the magnitude of the force of the point actuation is greater than a minimum magnitude;

wherein the minimum magnitude of the force of each of the point actuations is substantially equal at each of the respective positions on the touch sensitive front surface.

11. The load control device of claim 1, wherein the touch sensitive device is provided in a first plane and the touch sensitive front surface is provided in a second plane substantially parallel with the first plane.

12. The load control device of claim 11, wherein the touch sensitive front surface defines a first area and the touch sensitive device defines a second area larger than the first area.

13. The load control device of claim 12, further comprising:

a bezel defining the touch sensitive front surface, the bezel operable to extend through the opening of the faceplate; and

a force transmitter provided between the bezel and the touch sensitive device, the force transmitter operable to transmit the force of the point actuation on the touch sensitive front surface to the touch sensitive device.

14. The load control device of claim 13, wherein the force transmitter has a substantially constant force profile.

15. The load control device of claim 14, wherein the force transmitter comprises an elastomer.

16. The load control device of claim 15, wherein the elastomer has a durometer in the range of approximately 20 A to 80 A.

17. The load control device of claim 16, wherein the elastomer has a durometer of approximately 40 A.

18. The load control device of claim 15, wherein the elastomer is rubber.

19. The load control device of claim 15, wherein the elastomer is approximately 0.040″

thick.

20. The load control device of claim 13, further comprising:

a plurality of status indicators located behind the force transmitter;

wherein the force transmitter is made from a transparent material such that the status indicators are operable to shine through the force transmitter and onto the touch sensitive front surface.

21. The load control device of claim 20, wherein the status indicators are arranged in a linear array.

22. The load control device of claim 21, wherein the status indicators comprise light-emitting diodes.

23. The load control device of claim 13, wherein the bezel comprises sidewalls, the force transmitter located between the sidewalls of the bezel.

24. The load control device of claim 13, wherein a total force profile of the load control device is substantially constant across the second area of the touch sensitive front surface.

25. The load control device of claim 12, wherein an orthogonal projection of the second area onto the first area is encompassed by the first area.

26. The load control device of claim 25, wherein the force profile of the touch sensitive device is substantially constant across the orthogonal projection of the second area onto the first area.

27. The load control device of claim 25, wherein the touch sensitive device has edges, and a force required to actuate the touch sensitive device is substantially greater in an area near the edges;

and

wherein the area near the edges comprises the portion of the first area outside of the orthogonal projection of the second area on the first area.

28. The load control device of claim 11, wherein the touch sensitive front surface is adapted to be substantially flush with the front surface of the faceplate.

2. A user interface for a lighting control, the user interface comprising:

a touch sensitive front surface adapted to be provided in an opening of a faceplate, such that the touch sensitive front surface is provided either substantially coextensive with the opening of the faceplate or slightly beyond a front surface of the faceplate; and

a touch sensitive device responsive to a plurality of point actuations on the touch sensitive front surface,, each actuation characterized by a position and a force,

the touch sensitive device having an output for providing a control signal representative of the position of the point actuation and responsive to the point actuation when the magnitude of the force of the point actuation is greater than a minimum magnitude;

wherein the minimum magnitude of the force of each of the point actuations is substantially equal at each of the respective positions on the touch sensitive front surface.

3. A load control device for controlling the amount of power delivered to an electrical load from an AC power source, the load control device comprising:

a controllably conductive device operable to be coupled in series electrical connection between the source and the load, the controllably conductive device having a control input for controlling the controllably conductive device between a non-conductive state and a conductive state;

a controller operatively coupled to the control input of the controllably conductive device for controlling the controllably conductive device between the non-conductive state and the conductive state;

a faceplate having a front surface and an opening defining a first area;

a touch sensitive front surface having a second area substantially the same as the first area, the touch sensitive front surface adapted to be provided in the opening of the faceplate, such that the touch sensitive front surface is provided either substantially coextensive with the opening of the faceplate or slightly beyond the front surface of the faceplate; and

a touch sensitive device responsive to a plurality of point actuations on the touch sensitive front surface, each of the point actuations characterized by a position and a force, the touch sensitive device comprising an output operatively coupled to the controller for providing a control signal representative of the position of the point actuation;

wherein each of the point actuations is operable to actuate the touch sensitive device at any of the positions on the second area of the touch sensitive front surface.

29. The load control device of claim 3, wherein the touch sensitive device is provided in a first plane and the touch sensitive front surface is provided in a second plane substantially parallel with the first plane.

30. The load control device of claim 29, wherein the touch sensitive front surface defines a first area and the touch sensitive device defines a second area larger than the first area

31. The load control device of claim 30, further comprising:

a bezel defining the touch sensitive front surface and extending through the opening of the faceplate.

32. The load control device of claim 31, wherein an orthogonal projection of the second area onto the first area is encompassed by the first area.

33. The load control device of claim 32, wherein the touch sensitive device has edges, and a force required to actuate the touch sensitive device is substantially greater in an area near the edges;

and

wherein the area near the edges comprises the portion of the first area outside of the orthogonal projection of the second area on the first area.

34. The load control device of claim 33, wherein the bezel comprises substantially thin sidewalls.

35. The load control device of claim 34, wherein the sidewalls are approximately 0.010 inch thick.

36. The load control device of claim 34, wherein said sidewalls are operable to contact the touch sensitive device within the orthogonal projection of the second area onto the first area.

37. The load control device of claim 31, further comprising:

a force transmitter provided between the bezel and the touch sensitive device, the force transmitter operable to transmit the force of the point actuation on the touch sensitive front surface to the touch sensitive device.

38. The load control device of claim 37, further comprising:

a plurality of status indicators located behind the force transmitter;

wherein the force transmitter is made from a transparent material such that the status indicators are operable to shine through the force transmitter and onto the touch sensitive front surface.

39. The load control device of claim 38, wherein the status indicators are arranged in a linear array.

40. The load control device of claim 39, wherein the status indicators comprise light-emitting diodes.

41. The load control device of claim 37, wherein the force transmitter has a substantially constant force profile.

42. The load control device of claim 41, wherein the force transmitter comprises an elastomer.

43. The load control device of claim 29, wherein the touch sensitive front surface is substantially flush with the front surface of the faceplate.

4. A user interface for a lighting control, the user interface comprising:

a faceplate having a front surface and an opening defining a first area;

a touch sensitive front surface having a second area substantially the same size and shape as the first area, the touch sensitive front surface adapted to be provided in the opening of the faceplate, such that the touch sensitive front surface is provided either substantially coextensive with the opening of the faceplate or slightly beyond the front surface of the faceplate;

a touch sensitive device responsive to a plurality of point actuations on the touch sensitive front surface, each of the point actuations characterized by a position and a force;

wherein the touch sensitive device is operable to provide a control signal representative of the position of the point actuation;

wherein each of the point actuations is operab;

e to actuate the touch sensitive device at any of the positions on the second area of the touch sensitive front surface.

5. A control structure for an electrical control system for producing a variable output electrical signal to an electrical load for controllably varying an output of said load, said control structure comprising:

(a) an enclosed volume which contains electrical circuitry;

(b) a cover plate on one surface of said enclosed volume having a planar front surface and having a rectangular opening therein;

(c( a rectangular frame extending into said rectangular opening in said cover plate and having a thin front surface adapted to have an operating pressure applied thereto;

(d) a touch sensitive device having a front surface, said touch sensitive device disposed adjacent to and behind said rectangular opening and received in said rectangular frame, said thin front surface of said rectangular frame operable to permit the transmission of said operating pressure to said front surface of said touch sensitive device, said touch sensitive device coupled to said electrical circuitry and adapted to produce an output signal which is related to the position within an area of said touch sensitive device front surface corresponding to the position within an area of said front surface of said rectangular frame at which said operating pressure is applied;

wherein the area of said touch sensitive device is greater than the area of said front surface of said rectangular frane, whereby side edges of said touch sensitive device are unresponsive when pressure is applied to said front surface of said rectangular frame.

7. The control structure of claim 5, wherein said touch sensitive device has a width dimension greater than that of the rectangular opening in the front surface of said cover plate, thereby to improve the sensitivity of said touch sensitive device over the limited width of said touch sensitive device exposed through said rectangular opening.

8. The control structure of claim 7, further comprising:

Nan elastomer sheet between said rectangular frame and said touch sensitive device to facilitate transmision of said operating pressure to the surface of said touch sensitive device beneath said elastomer sheet.

9. The control structure of claim 5, wherein said touch sensitive front surface is substantially coplanar with said planar front surface.

10. The control structure of claim 5, wherein said touch sensitive front surface is disposed in a plane parallel to and above the plane of said planar front surface.

6. (canceled)