OPTICAL SENSOR APPARATUS WITH ADDITIONAL CAPACITIVE SENSORS

Abstract

The present disclosure relates to a sensor device for arrangement in a motor vehicle, including: a transmitting unit for emitting an optical signal into a space region of a passenger compartment of the motor vehicle; a receiving unit for sensing the optical signal; an evaluation unit for assigning a switching function and/or controlling function to the reflected optical signal; a cover which is transmissive with respect to the optical signal and disposed between the passenger compartment and the transmitting unit; and further, a capacitive sensor with at least one electrode for generating a measuring capacitance sensing the passenger compartment at least in some portions, and means for detecting a capacitance change of the measuring capacitance; and wherein the evaluation unit is further designed to vary the switching function and/or controlling function and/or to vary the transmitting power of the transmitting unit in accordance with the capacitance change.

Claims

1. A sensor device for arrangement in a motor vehicle, comprising: a transmitting unit configured to emit an optical signal into an enclosed compartment; a receiving unit configured to sense the optical signal reflected from the interior compartment; an evaluation unit for assigning to the optical signal at least one of: a switching function and a controlling function; a cover which is transmissive with respect to the optical signal and disposed between the interior compartment and the transmitting unit; and a capacitive sensor with at least one electrode for generating a measuring capacitance sensing the passenger compartment at least in some portions, and configured to detect a capacitance change of the measuring capacitance; and wherein the evaluation unit is further designed to vary at least one of: the switching function, the controlling function and the transmitting power of the transmitting unit in accordance with the capacitance change.

2. The sensor device of claim 1, wherein the measuring capacitance is configured to sense at least the interior compartment.

3. The sensor device of claim 1, wherein the interior compartment is immediately adjacent to the cover.

4. The sensor device of claim 1, wherein the transmitting unit emits light in the infrared range.

5. The sensor device of claim 1, wherein the at least one electrode is disposed between the transmitting unit and at least one of: the cover, the area surrounding the transmitting unit, and the area surrounding the cover.

6. The sensor device of claim 1, wherein the at least one electrode is disposed outside the interior compartment.

7. The sensor device of claim 1, wherein the sensor device is designed for sensing the optical signal reflected by a finger located on a surface of the cover and for determining an operating input or for generating an identification code in accordance with the sensed optical signal.

8. The sensor device of claim 7, wherein the evaluation unit is designed for determining the operating input by moving the finger along the surface of the cover based on a change of a speckle pattern of the optical signal sensed by the receiving unit.

9. The sensor device of claim 1, wherein the field and the means for detecting capacitance changes of the measuring capacitance generated by the at least one electrode are designed to detect a touch of a finger on the surface of the cover.

10. The sensor device of claim 1, wherein the cover is configured to be cup-shaped and the transmitting unit, the receiving unit and the evaluation unit are accommodated in a cavity defined by the cup-shaped cover.

11. The sensor device of claim 1, wherein the transmitting unit, the receiving unit and the evaluation unit are disposed on a common circuit board.

12. The sensor device of claim 10, wherein the electrode is disposed on a wall of the cup-shaped cover.

13. The sensor device of claim 12, wherein the electrode is formed by a metallic coating, preferably an aluminum coating, of the cover.

14. The sensor device of claim 1, wherein the transmitting unit is a semiconductor laser diode.

15. The sensor device of claim 1, wherein the capacitance change of the measuring capacitance is detected by means of a reference capacitance.

16. The sensor device of claim 1, further comprising: an operating member, including a switching means; and a movably mounted actuating part acting on the switching means in order to change the switching state of the switching means.

17. The sensor device of claim 1, wherein the sensor device is configured to be secured to a motor vehicle steering wheel.

18. The sensor device of claim 1 configured for use in a motor vehicle.

19. The sensor device of claim 1, wherein the interior compartment comprises a space region of a passenger compartment of the motor vehicle.

Description

[0027] In the figures:

[0028] FIG. 1 is a sectional view of the first embodiment of the sensor device according to the present disclosure;

[0029] FIG. 2 is a sectional view of an operating member 20 according to the present disclosure with a second embodiment of the sensor device according to the present disclosure;

[0030] FIG. 3 is a perspective detailed view of the second embodiment of the sensor device according to the present disclosure.

[0031] FIG. 1 shows a first embodiment of the sensor device 1 according to the present disclosure. The sensor device 1 has a translucent, cup-shaped cover 2. The cover 2 is inserted into an opening of a panel 13 which delimits a vehicle interior, also referred to as passenger compartment, at least in some portions. The cup-like cover 2 defines a cavity in which essential electronic elements 3, 4, 6 and a circuit board 5 are accommodated. The cup bottom of the cup-shaped cover 2 defines a window 12 into the passenger compartment 14, and, on the side thereof facing away from the cavity, a surface facing towards and delimiting the passenger compartment 14. A space region 8, which is, inter alia, monitored optically by the sensor device 1 according to the present disclosure, is adjacent to this surface of the cover 2. In the present case, the optical monitoring unit is a so-called fingerprint scanner. This optical monitoring unit comprises a transmitting unit 3 in the form of a semiconductor laser diode which emits an optical signal 9 into the space region 8 of the passenger compartment 14, and a receiving unit 4 for sensing the optical signal 10 reflected from the space region 8 of the passenger compartment 14, as it is caused, for example, by a finger 11 shown in FIG. 1. In order to activate the transmitting unit 3 and thus vary its transmitting power only when the finger 11 approaches the cover 2, a capacitive sensor is also provided, which defines a measuring capacitance sensing the space region 8. The measuring capacitance is defined by an electrode 7 producing an electrical field directed into the passenger compartment. The electrode 7 is configured as a metallic, continuous coating of the inner face of the peripheral cup wall 7b facing towards the cavity 15 and as a supporting edge 7a of the cover 2 provided for supporting the circuit board 5. Through the support edge 7a, the electrode 7 is electrically contacted with a conductor path of the circuit board 5. When the approach of the finger 11 towards the cover is detected through a corresponding change of the measuring capacitance, the evaluation unit 6 is to activate the transmitting unit 3, and when a sufficient distance of the finger 11 from the cover is detected through a corresponding change of the measuring capacitance, to deactivate the transmitting unit 3.

[0032] FIG. 2 shows an operating member 20 according to the present disclosure, wherein a second embodiment of the sensor device 1 according to the present disclosure defines an actuating part. The embodiment of the sensor device 1 shown in FIG. 2 differs from the first embodiment shown in FIG. 1 substantially by the configuration of the electrode 7. In this embodiment according to FIG. 2, the electrode 7 also extends over the surface 7c of the cup bottom of the cover 2 facing towards the cavity 15, with a window 12 remaining, which is sufficient for the optical monitoring unit consisting of the transmitting unit 3 and the receiving unit 4, as is apparent from FIG. 3, which shows a perspective view of the cavity 15 of the cover 2. The sensor device 1 is movably integrated into an opening of a panel of a cluster of other operating members, which are not shown and which are disposed in a spoke of a steering wheel. The sensor device 1 defines an actuating part of the operating member 20 according to the present disclosure. The surface 22 of the cover 2 facing towards the operator defines an actuating surface. On the side facing away from the operator and adjacent to the circuit board 5, a switching means 19 in the form of a switching dome of a keyboard mat 17 consisting of an elastic material is provided, wherein the switching dome 19, with its contact pill 18 consisting of a conductive material, is disposed above two contact surfaces disposed on another circuit board 16. An electrically conductive connection in the form of a flexible conductor 21 is provided between the other circuit board and the sensor device 1. The actuating part 1, i.e. the sensor device 1, cooperates with the switching dome 19 in such a manner that in the latter's final position, when the sensor device 1 has been pressed downwards against the restoring force caused by the elastic switching dome 19, the contact surfaces located on the other circuit board 16 are connected with each other in an electrically conductive manner by the contact with the contact pill 18, so that a switching state is thus changed.