DE102009041653B4 - Capacitive touch device - Google Patents

Abstract

Capacitive sensing device for a motor vehicle component for generating a switching signal when approaching and / or touching a plate-like sensor element (6,6 ') by a user (2), with a switching region of electrically conductive material on the side facing away from the user (2) dielectric material existing sensor element (6,6 '), with a on the user (2) side facing away from the sensor element (6,6') arranged printed circuit board (3,3 '), which carries a control device with the switching area is electrically conductively connected, with an on the circuit board (3,3 ') approximately the switching area opposite arranged light source (4) through which a arranged in the region of the switching region transilluminable area (11) of the sensor element (6,6') to the user ( 2) and is arranged in a light shaft (15,15 '), the erstre between the circuit board (3,3') and the sensor element (6,6 ') wherein the light shaft (15, 15 ') has one or more electrically conductive connecting lines of the switching region with the control device, and wherein the switching region and / or the connecting lines consist of an electrically conductive coating of the sensor element and / or of the light shaft (15, 15'). consist, and wherein the inner sides of one or more light shaft walls or shaft walls and / or the closure plate (16) are wholly or partially provided with the electrically conductive coating, characterized in that the recesses (21) in the circuit board (3 ') projecting ends (20) of the light shaft walls on the walls of the recesses (21) facing sides are provided with the electrically conductive coating.

Description

The invention relates to a capacitive sensing device, in particular for a motor vehicle component, for generating a switching signal when a plate-like sensor element approaches and / or contacts a user, with a switching region of electrically conductive material on the side of the dielectric material sensor element facing away from the user. with a on the side facing away from the user at a distance from the sensor element arranged circuit board, which carries a control device to which the switching area is electrically connected, with a on the circuit board approximately the switching area oppositely arranged light source, arranged by one in the region of the switching range transilluminable region of the sensor element to the user is transilluminable and which is arranged in a light well, which extends between the circuit board and the sensor element.

From the DE 10 2005 025 021 A1 a capacitive sensing device according to the preamble of claim 1 is known. From the DE 101 23 633 A1 a sensor element is known which is part of a capacitive touch switch. The EP 1 720 255 A1 shows a lighted capacitive push button. The DE 10 2006 035 837 A1 also shows a capacitive control element.

The object of the invention is to provide a capacitive sensing device of the type mentioned, which is improved over the known prior art.

This object is achieved by the measures specified in the characterizing part of claim 1.

Characterized in that the projecting through recesses in the circuit board ends of the light shaft walls on the walls of the recesses facing sides are provided with the electrically conductive coating, a good signal transmission is achieved.

Because the light shaft also has the electrically conductive connections from the switching region to the control device, the connection of the switching region to the control device takes place simultaneously with the assembly of the light shaft.

There are no additional contacting components to assemble and no space for the contacting components required.

Preferably, the sensor element and / or the light shaft made of an electrically insulating material and thus form carrier components without an isolation requirement.

One possibility is that the switching region and / or the connecting lines are in the sensor element and / or the light shaft inserted inserts made of an electrically conductive material.

The sensing device is easy to manufacture and essentially requires no installation space, since the switching region and / or the connecting lines consist of an electrically conductive coating of the sensor element and / or the light shaft.

An additional switching signal can be generated that the sensor element as counter to a spring force kraftbeaufschlagbares by the user and a key stroke movable sensing element and the printed circuit board within the light shaft, a pressure switch is arranged, the movement of the probe element against the spring force to the key stroke of the Tastelement can be acted upon.

For stable guidance of the sensor element, the sensor element preferably has one or more guide elements which project toward the side facing away from the user and which are displaceably guided in one or more corresponding guide recesses of a diaphragm.

In this case, the guide recesses can be one or more guide shafts of the diaphragm in a simple, component-saving manner.

An advantageous embodiment consists in the fact that the one or more guide shafts mutually parallel inner and outer shaft walls have, between which the guide elements are guided displaceably.

To stabilize the guide shafts can be closed at their ends facing away from the user.

If the guide shafts with their end facing away from the user on the circuit board in support, they also form spacers between the panel and the circuit board.

Are the connecting lines of the switching area with the control device for resting on the printed circuit board end face of the guide shafts and in contact bearing on one or more tracks of the circuit board, which lead to the control device, it is done with the assembly of the Light shaft at the same time a contact with the control unit.

Form the inner shaft walls, the light shaft, which is closed at its end facing the user by a closure plate having a the light-transmitting region of the sensor element opposite light passage area, the interior of the light shaft is closed to the user, so that no dirt can penetrate.
In a further likewise advantageous embodiment, the guide elements can form light shaft walls of the light shaft, whereby the light shaft is formed integrally with the sensor element.

For simple signal transmission from the switching area to the control device, one or more light shaft walls can project with their provided with the connecting lines, the user end facing with clearance through corresponding provided with through holes their walls recesses in the circuit board, wherein the vias form coupling capacitors with the connecting lines and the control device are connected.

The electrically conductive connections can be produced in a simple manner, since the inside of one or more light shaft walls or shaft walls and / or the closure plate are completely or partially provided with the electrically conductive coating.

It is easy to produce with good conductive properties if the conductive coating is a metallic coating, wherein the conductive coating can be applied galvanically or by sputtering.

If the conductive coating is light-reflecting, it fulfills a dual function and leads to a good backlighting of the transilluminable region of the sensor element.

• 1 eine perspektivische Schnittansicht eines ersten Ausführungsbeispiels einer kapazitiven Tastvorrichtung
• 2 eine zweite perspektivische Schnittansicht der kapazitiven Tastvorrichtung nach 1
• 3 eine perspektivische Schnittansicht eines zweiten Ausführungsbeispiels einer kapazitiven Tastvorrichtung
• 4 eine zweite perspektivische Schnittansicht der kapazitiven Tastvorrichtung nach 3.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below. Show it

• 1 a perspective sectional view of a first embodiment of a capacitive sensing device
• 2 a second perspective sectional view of the capacitive sensing device according to 1
• 3 a perspective sectional view of a second embodiment of a capacitive sensing device
• 4 a second perspective sectional view of the capacitive sensing device according to 3 ,

The capacitive sensing devices shown in the figures have an aperture 1 and one at a distance to the aperture 1 on the one user 2 opposite side of the panel 1 arranged circuit board 3 . 3. ' on.

A feeler element 5 . 5 ' has a touch plate 6 . 6 ' and to the user 2 opposite side protruding guide elements 7 . 7 ' on that through guide holes 8th in the aperture 1 to the circuit board 3 . 3. ' stick out.

The arranged as a rectangle to each other wall-like guide elements 7 . 7 ' are in manholes 9 Guided, the one-piece with the aperture 1 are trained and different from the user 2 directed away to the circuit board 3 . 3. ' extend.

Inside of the wall-like guide elements 7 . 7 ' enclosed area is on the circuit board 3 . 3. ' a light source 4 as well as a pressure switch 10 arranged over on the circuit board 3 . 3. ' arranged not shown interconnects is connected to a control device, also not shown, preferably also on the circuit board 3 . 3. ' is arranged.

In the otherwise opaque touch plate 6 . 6 ' are labeled as "OFF" and as a marker transilluminable areas 11 educated.

In the embodiment of the 1 and 2 own the manholes 9 at a distance parallel inner shaft walls 12 and outer shaft walls 13 that are at your the user's 2 opposite ends are closed and between which the wall-like guide elements 7 , 7 'are guided displaceably.

This is the feeler element 5 from its illustrated normal position by application of force by the user 2 a key stroke 14 against a spring force of a spring element, not shown, in the guide recesses 8th movable, causing the pressure switch 10 from the probe element 5 is operable.

The inner shaft walls 12 form a light shaft 15 , which at its end facing the user by a closure plate 16 is closed, one of the translucent area 11 the key plate 6 opposite light passage opening 17 having.

The insides of the inner shaft walls 12 as well as the closure plate 16 are galvanic with a chrome layer 18 provided, which is also on the circuit board 3 facing end face of the interconnected inner shaft walls 12 and outer shaft walls 13 extends and there is a contact surface 19 forms.

With this contact surface 19 are the shaft walls 12 . 13 on one or more tracks of the circuit board 3 contacting in circulation, leading to the control device.

The chrome layer 18 on the closure plate 16 forms an electrode and thus a switching region of a capacitive switch, wherein the closure plate 16 and the touch panel 6 form a dielectrics.

If a body part of the user gets close enough to the probe element 5 or acts on this, a switching signal is triggered and via the connecting line forming a chromium layer 18 on the inner shaft walls 12 as well as the contact area 19 and the conductor tracks of the control device supplied.

Because the chrome layer 18 is light-reflecting, it leads in a double function even to a good illumination of the transilluminable areas 11 the touch panel 6 ,

In the embodiment of the 3 and 4 form the wall-like guide elements 7 ' a light shaft 15 ' and stick out with their the Tastplatte 6 ' remote end areas 20 with play through recesses 21 in the circuit board 3. ' ,

The walls of the recesses 21 are one with a via 22 forming electrically conductive coating, via not shown interconnects of the circuit board 3. ' are connected to the control device.

The insides of the wall-like guide elements 7 ' as well as the touch plate 6 ' are galvanic with a chrome layer 18 ' provided by the recesses 21 projecting end portions 20 completely encloses.

This forms the end areas 20 with the recesses 21 coupling capacitors 23 ,
The chrome layer 18 ' on the touch panel 6 ' forms according to the chromium layer 18 on the closure plate 16 in the embodiment of 1 and 2 an electrode and thus a switching region of a capacitive switch, wherein the touch plate 6 ' forms a dielectric.

If a body part of the user gets close enough to the probe element 5 or acts on this, a switching signal is triggered and via the connecting line forming a chromium layer 18 ' on the guide elements 7 ' as well as the coupling capacitors 23 and the conductor tracks of the control device supplied.

Again, the light-reflecting chromium layer leads 18 ' to a good illumination of the transilluminable areas 11 the touch panel 6 ' ,

According to the embodiment of the 1 and 2 is the feeler element 5 ' also against a spring force of the user movable and the pressure switch 10 actuated.

LIST OF REFERENCE NUMBERS

1

cover

2

user

3

circuit board

3 '

circuit board

4

light source

5

scanning element

5 '

scanning element

6

Touch plate

6 '

Touch plate

7

guide element

7 '

guide element

8th

guide recesses

9

guide shafts

10

pressure switch

11

translucent area

12

inner shaft walls

13

outer shaft walls

14

key travel

15

light well

15 '

light well

16

closure plate

17

Light aperture

18

chromium layer

18 '

chromium layer

19

contact area

20

end regions

21

recesses

22

via

23

double capacitors

Claims (16)

Capacitive sensing device for a motor vehicle component for generating a switching signal when approaching and / or touching a plate-like sensor element (6,6 ') by a user (2), with a switching region of electrically conductive material on the side facing away from the user (2) dielectric material existing sensor element (6,6 '), with a on the user (2) side facing away from the sensor element (6,6') arranged printed circuit board (3,3 '), which carries a control device with the switching area is electrically conductively connected, with an on the circuit board (3,3 ') approximately the switching area opposite arranged light source (4) through which a arranged in the region of the switching region transilluminable area (11) of the sensor element (6,6') to the user ( 2) and is arranged in a light shaft (15,15 '), the erstre between the circuit board (3,3') and the sensor element (6,6 ') wherein the light shaft (15, 15 ') has one or more electrically conductive connecting lines of the switching region with the control device, and wherein the switching region and / or the connecting lines consist of an electrically conductive coating of the sensor element and / or of the light shaft (15, 15'). consist, and wherein the inner sides of one or more light shaft walls or shaft walls and / or the closure plate (16) are wholly or partially provided with the electrically conductive coating, characterized in that the recesses (21) in the circuit board (3 ') projecting ends (20) of the light shaft walls on the walls of the recesses (21) facing sides are provided with the electrically conductive coating. Capacitive touch device after Claim 1 , characterized in that the sensor element and / or the light shaft (15, 15 ') consist of an electrically insulating material. Capacitive touch device after Claim 2 , characterized in that the switching region and / or the connecting lines are in the sensor element and / or the light shaft inserted inserts made of an electrically conductive material. Capacitive sensing device according to one of the preceding claims, characterized in that the sensor element is designed as a force-sensitive against a spring force by the user (2) and a Tastenhub (14) movable sensing element (5, 5 ') and on the circuit board (3, 3' ) within the light shaft (15, 15 '), a pressure switch (10) is arranged, which can be acted upon movement of the probe element (5, 5') against the spring force to the key stroke (14) of the probe element (5, 5 '). Capacitive touch device after Claim 4 , characterized in that the sensor element one or more to the side facing away from the user (2) side protruding guide elements (7, 7 '), which are guided displaceably in one or more corresponding guide recesses (8) of a diaphragm (1). Capacitive touch device after Claim 5 , characterized in that the guide recesses (8) one or more guide shafts (9) of the diaphragm (1). Capacitive touch device after Claim 6 , characterized in that the one or more guide shafts (9) have mutually parallel inner and outer shaft walls (12, 13), between which the guide elements (7) are guided displaceably. Capacitive touch device after Claim 7 , characterized in that the guide shafts (9) are closed at their ends remote from the user (2). Capacitive touch device after Claim 8 , characterized in that the guide shafts (9) with their the user (2) facing away from the printed circuit board (3, 3 ') in support. Capacitive touch device after Claim 9 , characterized in that the connecting lines of the switching area with the control device on the printed circuit board (3) resting end side of the guide shafts (9) and in contact bearing on one or more tracks of the printed circuit board (3) leading to the control device. Capacitive sensing device according to one of Claims 7 to 10 , characterized in that the inner shaft walls (12) form the light shaft (15), which is closed at its end facing the user (2) by a closure plate (16), the light transmission area (11) of the sensor element opposite ( 17). Capacitive sensing device according to one of Claims 4 to 6 , characterized in that the guide elements (7 ') form light shaft walls of the light shaft (15'). Capacitive touch device after Claim 12 , characterized in that one or more light shaft walls with their provided with the connecting lines, the user facing away from the end (20) with play through corresponding with vias (22) provided with their walls recesses (21) in the circuit board (3 '), wherein the Through holes (22) with the Connecting lines coupling capacitors (23) form and are connected to the control device. Capacitive sensing device according to one of Claims 3 to 13 , characterized in that the conductive coating is a metallic coating. Capacitive sensing device according to one of Claims 3 to 13 Characterized in that the conductive coating is applied galvanically or by sputtering. Capacitive sensing device according to one of Claims 3 to 13 , Characterized in that the conductive coating is light-reflecting.

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