Vehicle switch assembly with proximity activated illumination

BACKGROUND OF THE INVENTION

This invention relates to a vehicle switch assembly with proximity activated illumination.

Modern vehicles include a large number of electrical input switches, such as door lock/unlock, window open/close, seat control switches, etc. These electrical input switches may include a backlighting or illumination feature which is operated simultaneously with the headlights of the vehicle. The backlighting or illumination feature is intended to assist a driver or other vehicle occupant in locating the input switch during low light conditions. Typically, when the vehicle headlights are switched on, the electrical input switches are backlit by a bulb or LED (light emitting diode) positioned underneath the cover of the switch or illuminated by a beam of light directed at the switch from a remote location. When the vehicle headlights are switched off, the backlighting or illumination of the electrical input switches is also switched off.

Backlit switches are easily located in the dark, however some illumination deficiencies remain. For example, it may be difficult to locate an input switch at dusk when the vehicle headlights, and therefore the switch backlighting/illumination, are off. Further, continuously backlit switches may create nighttime glare problems. Accordingly, there is a desire to provide a vehicle switch assembly which is illuminated only when the driver or other vehicle occupant reaches to use the switch.

SUMMARY OF THE INVENTION

In a disclosed embodiment of this invention, a vehicle switch assembly includes a switch for producing a signal to control a vehicle accessory, a light for illuminating the assembly, and a sensor for actuating the light in response to detecting an object in proximity to the switch. Preferably, the switch is illuminated only when a hand of a vehicle occupant is placed within a predetermined distance of the switch.

In a preferred embodiment of this invention, the light consists of a bulb for producing a beam of light and a fiber optic light pipe optically connected to the bulb for receiving the beam of light and illuminating the switch assembly.

In another preferred embodiment of this invention, the sensor consists of a foil strip and the switch assembly further includes a control having an illumination circuit. The approach of the occupant's hand towards the switch assembly changes the capacitance of the foil strip which triggers the illumination circuit to illuminate the light.

These and other features of the present invention will be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is a top view of a vehicle switch assembly in accordance with the present invention.

FIG. 2A

is an enlarged, cross-sectional view of the vehicle switch assembly taken along lines

2

A—

2

A in

FIG. 1

, showing the vehicle switch assembly installed in a vehicle.

FIG. 2B

is an enlarged view along line

2

B of FIG.

2

A. Notably, the line

2

B of

FIG. 2B

is a mirror image of FIG.

2

B.

FIG. 3

is an electrical schematic diagram of the vehicle switch assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1

is a top view of a vehicle switch assembly

10

in accordance with the present invention. The switch assembly

10

is intended to control one or more vehicle accessories or functions. For example purposes, the switch assembly

10

shown in

FIG. 1

is designed to control the movement of a power seat. However, the present invention extends to other switches. The switch assembly

10

includes a housing

12

, a plurality of switch covers

14

, and a plurality of locking tabs

16

extending outward from the housing

12

. Typically, the switch covers

14

are silkscreened or embossed with indicia

18

symbolizing the control function of the switch assembly

10

. The illustrated switch assembly

10

consists of eight switch covers

14

configured to form a figure of a seat

19

and each switch cover

14

includes indicia

18

, here a triangle, indicating the direction of control or movement of the seat respectively. The invention of this application extends to other switches, and the illustrated switch is shown only as an example.

FIG. 2A

is an enlarged, cross-sectional view of the vehicle switch assembly

10

taken along lines

2

A—

2

A in FIG.

1

. The switch assembly

10

is shown installed in a vehicle

20

, illustrated schematically. The locking tabs

16

mount the switch assembly

10

to the vehicle

20

. Typically, the switch assembly

10

is snapped into an inner front door trim piece

22

in the vehicle

20

. In this manner, the switch assembly

10

may be installed into the vehicle

20

without the use of tools or fasteners. The switch covers

14

of the assembly

10

are preferably mounted flush with the surface of the inner front door trim piece

22

. Mounting the switch assembly

10

flush with the surface of the inner front door trim piece

22

reduces the possibility of unintentional activation of the switch assembly

10

causing the seat to move.

The switch assembly

10

includes a plurality of switches

24

for producing signals to control a vehicle accessory and a light

26

for illuminating the switch assembly

10

. As shown in

FIG. 2B

, a sensor

28

for actuating the light

26

in response to detecting an object in proximity to the switch assembly

10

is incorporated into the housing

12

.

The plurality of switches

24

consists of conventional low current tack switches as shown in FIG.

2

A. Each switch

24

is covered by a switch cover

14

respectively. To move the seat in a specific direction, a vehicle occupant must depress the appropriate switch cover

14

to activate the respective switch

24

. Each switch cover

14

is attached to the switch assembly

10

with a living hinge

30

. After a switch cover

14

has been depressed, the respective living hinge

30

returns the switch cover

14

to a normally raised position.

Light

26

may be any type of illumination device, including a bulb or LED (light emitting diode), positioned anywhere within the vehicle

20

provided the light

26

can illuminate the switch covers

14

. Accordingly, the light

26

may be positioned underneath the switch covers

14

, adjacent the switch covers

14

, or at a remote location from the switch assembly

10

.

In further accordance with the spirit of the present invention, the sensor

28

may be any type of detecting device, including a motion sensor, heat sensor, or proximity sensor, provided that the sensor

28

can detection the presence of a hand within a predetermined distance or proximity of the switch assembly

10

. Such sensors are known, and the provision of such sensors is within the skill of a worker in the art.

In a preferred embodiment of the present invention, the switch assembly

10

includes a control

32

for receiving an actuation signal from the sensor

28

when an object is detected in proximity to the switch assembly

10

and for actuating the light

26

in response to the actuation signal. Preferably, the control

32

is an integrated circuit (IC).

The light

26

consists of a bulb

34

for producing a beam of light and a fiber optic light pipe

36

optically connected to the bulb

34

and positioned about the perimeter of the switch assembly

10

for receiving the beam of light and illuminating the switch assembly

10

. In this embodiment, the fiber optic light pipe

36

is routed underneath an applique

38

about the perimeter of the switch covers

14

or the figure of the seat

19

, best seen in FIG.

1

.

Preferably, the switch assembly

10

further includes a circuit board

40

for supporting the plurality of switches

24

, the bulb

34

, and the control

32

. Additionally, the switch assembly

10

includes a connector

42

molded in the housing

12

and integrated with the circuit board

40

.

FIG. 3

is an electrical schematic diagram of the vehicle switch assembly

10

. The sensor

28

is designed to detect a hand

44

approaching the switch assembly

10

. The sensor

28

consists of a foil strip

46

, a capacitance triggered switching circuit

48

, and a voltage regulator to maintain a stable operation voltage. The switching circuit

48

is housed in the control

32

. The foil strip

46

is a strip of metal routed underneath the applique

38

, best seen in

FIG. 2B

, about the perimeter of the switch covers

14

or the figure of the seat

19

, best seen in FIG.

1

. The foil strip

46

operates as an input circuit to the switching circuit

48

. The circuit

48

provides voltage on the foil strip

46

. When a hand

44

is placed within a predetermined distanced, d, of the foil strip

46

, the capacitance of the foil strip

46

is changed. The change in the capacitance of the foil strip

46

triggers a one-shot timer circuit in the switching circuit

48

and illuminates the bulb

34

. The on-time of the one-shot timer circuit can be adjusted by changing the resistance or capacitance to change the time constant of the one-shot timer circuit. The bulb is illuminated until the one-shot timer circuit times out. One of ordinary skill in the art will recognize that the switching circuit

48

may be designed to illuminate the bulb

34

only when the hand

44

is within the predetermined distance, d, of the foil strip

46

instead of illuminating the bulb

34

for the on-time of the one-shot timer circuit. The beam of light created by the illuminated bulb

34

is transmitted by the fiber optic light pipe

36

to illuminate the switch assembly

10

. In the aforementioned example, the switches

14

of the assembly

10

control one or more seat motors

50

. The specific sensing technology described is known generally for detecting objects; however, the use of the sensing technology to actuate a light or in a vehicle switch application is novel.

Preferred embodiments of this invention have been disclosed, however, a worker of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.