Occupancy sensor assembly

1. An occupancy sensor, comprising:

a housing with an interior cavity;

a switch configured for placement in the open and closed positions, the switch being mounted substantially in the interior cavity of the housing;

a sensor module mounted inside the interior cavity of the housing and supporting said switch; and

a removable fascia cover configured for coupling to the housing to enclose the interior cavity, the fascia cover having a fascia rib on an interior surface, the fascia rib being arranged to interfere with the switch in the open state to prevent the fascia cover plate from being coupled to the housing when the switch is in the open position.

2. An occupancy sensor according to claim 1 , wherein

the sensor module comprises a power board and a sensor board.

3. An occupancy sensor according to claim 1 , further comprising

at least one ultrasonic transducer mounted on a sensor board.

4. An occupancy sensor according to claim 1 , further comprising

an infrared sensor mounted on the sensor board.

5. An occupancy sensor according to claim 1 , wherein

said fascia rib is positioned on a side edge of said fascia cover plate to interfere with said switch in the open state and without interfering with said switch in a closed state.

6. The occupancy sensor of claim 1 , wherein

said fascia rib is oriented to contact said switch when said switch is open to prevent said fascia cover from coupling to said housing and is oriented to prevent contact with said switch when said switch is closed to allow said fascia cover to be coupled to said housing.

7. The occupancy sensor of claim 1 , wherein

said fascia cover has a bottom face with a side edge for coupling to said housing, and where said fascia rib is positioned along said side edge to contact said switch when in the open position to prevent said edge from coupling to said housing.

8. An occupancy sensor, comprising:

an infrared sensor;

a mounting plate with a window to allow energy to pass through onto the infrared sensor, the mounting plate having a raised guide surrounding said window, said raised guide extending outwardly from a front side of said mounting plate and having angled surfaces to define a field of view for said infrared sensor and converging inwardly toward said window in said mounting plate at an incline with respect to a plane of said mounting plate; and

a lens with a front wall and side walls extending from said front wall and configured for positioning over the raised guide to position the lens relative to the window in the mounting plate and the infrared sensor.

9. An occupancy sensor according to claim 8 , wherein

the front wall of the lens is substantially curved.

10. An occupancy sensor according to claim 8 , wherein

the raised guide comprises four substantially vertical walls.

11. An occupancy sensor according to claim 10 , wherein

the vertical walls extend to a bottom surface of the front wall of said lens and where said front wall of said lens is substantially curved.

12. An occupancy sensor according to claim 8 , wherein

said occupancy sensor includes a switch operatively connected to said infrared sensor, and where the mounting plate has a slot aligned with said switch to allow access to said switch.

13. An occupancy sensor according to claim 8 , further comprising

an ultrasonic transducer extending through the mounting plate.

14. An occupancy sensor of claim 8 , wherein

said raised guide positions said lens to position a focal point of said lens relative to the infrared sensor.

15. An occupancy sensor according to claim 8 , wherein

said raised guide positions said lens relative to the infrared sensor and prevents the lens from deforming under pressure.

16. An occupancy sensor according to claim 8 , wherein

said mounting plate includes at least one pin; and

said lens includes a projection having an aperture therein for receiving said pin.

17. The occupancy sensor of claim 8 , further comprising

a housing supporting said infrared sensor, said mounting plate being coupled to said housing; and

a fascia cover overlying said mounting plate and being coupled to said housing, said fascia cover having an opening receiving said lens.

18. The occupancy sensor of claim 8 , wherein

said side walls of said lens have a configuration to surround said raised guide, said side walls having a bottom edge opposite said front wall and coupled to said mounting plate.

19. The occupancy sensor of claim 17 , wherein

said occupancy sensor includes a switch movable between an open position and a closed position, and where said fascia cover has an inner surface with a fascia rib oriented to interfere with said switch in the open position to prevent coupling of said fascia cover to said housing.

20. The occupancy sensor of claim 8 , wherein

said angled surfaces extend from a top edge of said raised guide to said window in said mounting plate.