Abstract
An actuation plate with symbol illumination for a sensor switch button includes a support plate with a first surface on which a metal layer is applied. A luminous layer of light-scattering material is applied on the support plate and at least partially on the metal layer. An opening is provided in the support plate through which a first end of a light guide projects, and a second end of the light guide is optically connected to a light source. The luminous layer is adjacent to the first end of the light guide.
Claims
1. An actuation plate with symbol illumination for a sensor switch button, said plate comprising: a support plate with a first surface on which a metal layer is applied, wherein a luminous layer of light-scattering material is applied on the support plate and at least partially on the metal layer, and wherein an opening is defined in the support plate through which a first end of a light guide projects, a second end of the light guide is optically connected to a light source, and the luminous layer is adjacent to the first end of the light guide.
2. The actuation plate according to claim 1, wherein the opening extends through the metal layer.
3. The actuation plate according to one of the preceding claims, characterized in that the luminous layer has a layer thickness of 1 mm to 2 mm.
4. The actuation plate according to claim 1, wherein the luminous layer has a circular circumference, wherein the layer thickness of the luminous layer is one tenth of the diameter of the luminous layer.
5. The actuation plate according to claim 1, wherein the support plate is without openings in the area in which the luminous layer is adjacent to the metal layer and the support plate.
6. The actuation plate according to claim 1, wherein the light source is attached to the second surface so that the emitted light emits directly into the opening.
7. The actuation plate according to claim 1, wherein the luminous layer is spaced apart from the edge of the support plate.
8. The actuation plate according to claim 1, wherein the luminous layer spreads conically or curved from the support plate.
9. The actuation plate according to claim 1, wherein the first end of the light guide has a decoupling surface that is formed complementary to the side wall of the luminous layer.
10. The actuation plate according to claim 1, wherein the light guide has a plurality of first ends which are arranged along the circumference of the luminous layer.
11. The actuation plate according to claim 1, wherein the luminous layer contains luminescent material which is suitable to produce white light from higher-energy light.
12. The actuation plate according to claim 1, wherein the support plate is a printed circuit board and forming the sensor surface of a capacitive sensor with a plurality of closely spaced conductor surfaces largely covering the first surface.
13. The actuation plate according to claim 12, characterized in that a cross-sectional area of the opening is substantially smaller than a surface area of the conductor surfaces of the capacitive sensor.
14. The actuation plate according to claim 1, wherein the actuation plate is movably arranged and the light guide is formed of at least one polymer optical fiber.
15. A sensor switch button comprising an actuation plate according to claim 1.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0026] In the following, the invention is described by means of an advantageous embodiment only by way of example with reference to the attached figures in which:
[0027] FIG. 1 shows a sensor switch button with integrated actuation plate and symbol illumination in a sectional view;
[0028] FIG. 2 shows a top view of an actuation plate;
[0029] FIG. 3 shows the structure of an actuation plate with symbol illumination in a sectional view;
[0030] FIG. 4 shows an alternative structure of a sensor switch button with actuation plate and symbol illumination;
[0031] FIG. 5 shows a top view of an actuation plate; and
[0032] FIG. 6 shows the first end of a light guide and the adjacent area of the luminous layer.
DETAILED DESCRIPTION
[0033] FIG. 1 shows a sensor switch button 1 with integrated actuation plate 10 and symbol illumination. The first surface 13 of the actuation plate 10 is covered by a cap 17. The cap 17 serves to protect the sensor surface and to hold the actuation plate 10 on the housing 2 of the switch. The cap 17 has a recess in the middle area of the surface into which a luminous layer 30 is embedded. Light guides 20 extend in the direction of the actuation plate 10 from a light source 40 which is attached to a second printed circuit board. The light guides 20 reach the actuation plate 10 at the second surface 13b. In this embodiment, the actuation plate 10 is movably connected to the housing 2. Here, the light guides 20 are formed of flexible polymer optical fibers.
[0034] FIG. 2 shows a top view of the first surface 13 of the actuation plate 10. A plurality of metal layers 15 are applied to a support plate 12, which are separated by narrow areas from one another. Here, the metal layers 15 are shown as a series of strips. These conductor surfaces 16 form the sensor elements of a capacitance sensor. A luminous layer 30 is shown centrally on the first surface 13 and spaced apart from the edge 11 of the support plate 12. A plurality of first ends 22 of a light guide 20 are shown at the edge of the luminous layer 30. The first ends 22 are distributed uniformly along the circumference of the luminous layer 30.
[0035] FIG. 3 shows the basic structure of an actuation plate 10 with symbol illumination in a sectional view. A luminous layer 30 is attached to the first surface 13 of a support plate 12. Preferably, the luminous layer 30 is located on the support plate 12 and/or on the metal layer. An edge area 35 extends along the circumference of the luminous layer 30, which is adjacent to the support plate 12. Adjacent to the edge area 35 of the luminous layer 30, an opening 14 is provided in the support plate 12 through which the first end 22 of a light guide 20 projects. The first end 22 of the light guide 20 and the side wall 32 of the luminous layer 30 are formed such that the first end 22 of the light guide 20 adjoins the side wall 32. The second end 23 of the light guide 20 is optically connected to a light source 40.
[0036] FIG. 4 shows an alternative structure of a sensor switch button 1 with actuation plate 10 and symbol illumination in a sectional view. To improve the lighting of the symbol illumination, a structure with two first ends 22 of the light guide 20 is shown herein. The first ends 22 of the light guide 20 are attached to opposite side walls of the luminous layer 30. The light guides are combined to the light guide 20 and form a single second light guide end 23. The second light guide end is optically connected to a light source 40. A cap 17, surrounding the luminous layer 30, is provided on the first surface 13 in the area outside the luminous layer 30 for protection of the first surface. The layer thickness of the cap 17 is matched to the layer thickness 31 of the luminous layer 30.
[0037] FIG. 5 shows a top view of an actuation plate 10. In this top view of the first surface 13 of the actuation plate 10, the openings 14 are shown without the first ends 22 of the light guide 20. The conductor surfaces 16 cover almost the entirety of the first surface 13 of the support plate 12. The openings 14 extend through the support plate 12 and additionally, in areas, through the conductor surfaces 16. The conductor surfaces 16 occupy much larger areas than the openings 14.
[0038] FIG. 6 shows the first end 22 of a light guide 20 and the adjacent area of the luminous layer 30. The first end 22 of the light guide 20 is prepared such as to correspond to the side wall 32 of the luminous layer 30. This means that the largest possible amount of light is transmitted from the decoupling surface 25 of the first end 22 of the light guide 20 to the coupling surface 34 of the luminous layer 30. Here, the first light guide end 22 is provided with a flat surface at an angle. The side wall 32 of the luminous layer 30 is also provided with a flat surface at a corresponding position, which is arranged at a corresponding angle. If these two surfaces are arranged adjacent to each other, the largest amount of light is transmitted.
[0039] While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.
