Arrangement for illuminating a switch surface for a touch sensor switch

• US 20030210537A1
• Filed: 05/02/2003
• Published: 11/13/2003
• Est. Priority Date: 05/07/2002
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Engelmann, Harry
• Granted Patent: US 7,142,189 B2
• Time in Patent Office: Days
• US Class Current: 362/26
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/006 to produce indicia, symbols, texts or the like
• CPC Class Codes: H03K 17/96 Touch switches specially adapted for electronic time-pieces with no moving parts G04G21/08
• CPC Class Codes: H03K 2217/96076 with spring electrode
• CPC Class Codes: H03K 2217/96079 using a single or more light guides

Abstract

The arrangement for illuminating at least one switch surface (3) provided on a transparent panel (1) has at least one light source (9) and a touch sensor switch (5) arranged behind the at least one switch surface (3). The illumination should not interfere with the switching function and a touch sensor switch (5) does not need its own light source (9). The light source (9) is spaced from the at least one switch surface (3) so that the at least one light source (9) radiates light into the transparent panel (1) or into an optical waveguide (15, 16, 17. 19. 20) arranged on the transparent panel (1). The light of the at least one light source (9) is guided into the transparent panel or the optical waveguide toward the at least one switch surface (3) and conducted into a region between the at least one switch surface (3) and a sensor element (7) of the touch sensor switch (5).

Claims

1. An arrangement for illuminating at least one switch surface (3) provided on a transparent panel (1), said arrangement comprising at least one light source (9) and a touch sensor switch (5) arranged behind the at least one switch surface (3), wherein the at least one light source (9) is positioned and spaced from the at least one switch surface (3) so that the at least one light source (9) radiates light into the transparent panel (1) or into a light waveguide (15, 16, 17, 19, 20) arranged on the transparent panel (1), said light of the at least one light source (9) guided into the transparent panel or the optical waveguide is guided toward the at least one switch surface (3) and conducted into a region between the at least one switch surface (3) and a sensor element (7) of the touch sensor switch (5).

2. The arrangement as defined in claim 1, wherein a scatter zone (10) is arranged in the vicinity of the at least one switch surface (3) in the transparent panel (1) or in the light waveguide, so that the scatter zone (10) directs the light from the at least one light source (9) to the at least one switch surface (3).

3. The arrangement as defined in claim 2, wherein a path of the light from the at least one light source (9) between the at least one light source (9) and the scatter zone (10) is arranged, so that total reflection of said light occurs.

4. The arrangement as defined in claim 1, wherein said at least one switch surface (3) comprises a plurality of switch surface regions, and further comprising a respective light guiding element for each of said switch surface regions.

5. The arrangement as defined in claim 1, wherein said transparent panel (1) has a printed region (14) at the at least one light source (9) and said printed region optically masks or covers the at least one light source.

6. The arrangement as defined in claim 1, wherein said at least one light source (9) comprises a plurality of lighting devices and said lighting devices provide at least one of different colored light and different intensity light or said at least one light source consists of a single lighting device having at least one of a variable color and variable intensity.

7. The arrangement as defined in claim 2, wherein said scatter zone (10) is formed by an engraving, a frosting or a single or multicolor printing on a rear side (4) of the transparent panel (1) facing the at least one switch surface (3).

8. The arrangement as defined in claim 2, wherein said scatter zone (10) is formed so that said scatter zone (10) is visible when said at least one light source (9) is turned off.

9. The arrangement as defined in claim 1 wherein said light waveguide comprises a transparent adhesive strip, which is glued on at least one of the panel (1) and a circuit board (6) carrying the at least one light source (9).

10. The arrangement as defined in claim 9, wherein said transparent adhesive strip comprises a transparent supporting strip (23) and an adhesive film (24,25) adhering on at least one side of the supporting strip or said transparent adhesive strip comprises a light-transmitting adhesive film (26).

11. The arrangement as defined in claim 10, wherein said adhesive film is provided with a non-adhesive covering foil (27) on one side thereof.

12. The arrangement as defined in claim 9, wherein said adhesive strip is provided with a cavity (30) in which said at least one light source (9) extends or is glued over said at least one light source (9).

13. The arrangement as defined in claim 9, further comprising an additional nontransparent, white or colored layer (34) provided between the light waveguide and the circuit board (6).

14. The arrangement as defined in claim 9, further comprising a frame (31) attached to the circuit board (6) and wherein the light waveguide sits in said frame (31).

15. The arrangement as defined in claim 1, further comprising a plurality of optical fibers and wherein light from a common lighting device is guided to the light waveguide by means of said optical fibers.

16. The arrangement as defined in claim 1, wherein the transparent panel (1) is composed of plastic, glass or glass ceramic material.