Contact switching arrangement

• US 20050006213A1
• Filed: 05/07/2004
• Published: 01/13/2005
• Est. Priority Date: 05/07/2003
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Engelmann, Harry
• Granted Patent: US 6,958,459 B2
• Time in Patent Office: Days
• US Class Current: 200/310
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9604 characterised by the number of electrodes
• CPC Class Codes: H03K 2217/96077 comprising an electrode which is floating
• CPC Class Codes: H03K 2217/960775 Emitter-receiver or "fringe" type detection, i.e. one or more field emitting electrodes and corresponding one or more receiving electrodes
• CPC Class Codes: H03K 2217/960785 with illumination

Abstract

A contact switching arrangement with a flat electrically non-conducting cover which forms a switching area on a top facing the user, and has an underside facing away from the user, at which at least one electrode is arranged and is connected with a switching arrangement for triggering a contact signal when a finger of the user or a similar conducting body approaches. The cover has a light-reflecting, electrically non-conducting film, at least over portions, which acts as a non-conductor. The contact switching arrangement is for use in connection with control panels of electronic devices, for example.

Claims

1. A contact switching arrangement with a flat, electrically non-conducting cover (10) which forms a switching area (14a, 14b) on a top (12) facing an user and has an underside (16) facing away from the user, at which at least one electrode (18a, 18b, 20a, 20b) is arranged and is connected with a switching arrangement (22) for triggering a contact signal when a finger of the user or a conducting body approaches, the contact switching arrangement comprising:

a light-reflecting, electrically non-conducting film (24) over at least a portion of the cover, acting as a non-conductor.

2. The contact switching arrangement in accordance with claim 1, wherein the film (24) is formed by a multi-layered non-metallic polymer film which reflects light in a mirror-like manner.

3. The contact switching arrangement in accordance with claim 2, wherein the multi-layered polymer film reflects more than 95% of visible light in a wave range of lambda=400 nm to 700 nm.

4. The contact switching arrangement in accordance with claim 3, wherein the multi-layered polymer film reflects light at an angle of incidence of 0°

to 90°

.

5. The contact switching arrangement in accordance with claim 4, wherein two lower electrodes (18a and 18b, 20a and 20b) are arranged next to each other on the underside (16) of the cover (10), and an upper electrode (26a, 26b) is arranged on the switching area (14a, 14b), and have a length that covers the two electrodes (18a and 18b, 20a and 20b) arranged on the underside (16), which are wired together as a series connection of two capacitors and are capacitively connected by the upper electrode (26a, 26b).

6. The contact switching arrangement in accordance with claim 5, wherein the upper electrode (26a, 26b) is made of a transparent material.

7. The contact switching arrangement in accordance with claim 4, wherein two electrodes (18a and 18b, 20a and 20b) are arranged next to each other on the underside (16) of the cover (10), which are connected with a switching arrangement (22) for generating an electrical alternating field (28a, 28b) which penetrates the cover (10) at least near the switching area (14a, 14b) and for detecting disturbances of the electrical alternating field (28a, 28b) in case of the approach of the finger of the user, or of a similar conducting body, to the switching area (14a, 14b).

8. The contact switching arrangement in accordance with claim 6, wherein the cover is made from the light-reflecting film (24).

9. The contact switching arrangement in accordance with claim 8, wherein the cover (10) is formed of a transparent plate (30), which has the switching area (14a, 14b) on the top (12) facing the user, and the light-reflecting film (24) on the underside (16) facing away from the user.

10. The contact switching arrangement in accordance with claim 9, wherein the cover (10) is formed by a non-conducting plate (30) which has the light-reflecting film (24) and the switching area (14a, 14b) on the top (12) facing the user.

11. The contact switching arrangement in accordance with claim 10, wherein the light-reflecting film (24) is applied to the transparent plate (30) by one of a lamination, a heat-seal, an adhesive and a fixed planar connection.

12. The contact switching arrangement in accordance with claim 11, wherein the transparent plate (30) is made of one of a glass, a plastic and a transparent material.

13. The contact switching arrangement in accordance with claim 12, wherein the light-reflecting film (24) has one of a smooth, a mirrored, and a structured surface, which reflects light in a diffuse manner.

14. The contact switching arrangement in accordance with claim 13, wherein the light-reflecting film (24) transmits light at least partially in a visible wavelength range.

15. The contact switching arrangement in accordance with claim 14, wherein at least one illuminated display (32a, 32b, 32c) is arranged on one of the underside (16) of the cover (10) and the light-reflecting film (24) facing away from the user.

16. The contact switching arrangement in accordance with claim 15, wherein the illuminated displays (32a, 32b, 32c) are formed by at least one of lamps, light-emitting diodes, self-illuminated graphic displays, 7-segment displays, backlit liquid crystal displays, backlit symbols and optical displays radiating through the light- reflecting film.

17. The contact switching arrangement in accordance with claim 16, wherein the position of the switching area (14a, 14b) is identified by at least one of a symbolic device and a similar marking ((34a, 34b, 34c, 34d) on at least one of the cover (10) and the light-reflecting film (24).

18. The contact switching arrangement in accordance with claim 17, wherein the light-reflecting film (24) is flexible, and the flat cover (10) at least in some areas is one of curved, angled and has shapes differing from a flat shape.

19. The contact switching arrangement in accordance with claim 2, wherein the multi-layered polymer film reflects light at an angle of incidence of 0°

to 90°

.

20. The contact switching arrangement in accordance with claim 1, wherein two lower electrodes (18a and 18b, 20a and 20b) are arranged next to each other on the underside (16) of the cover (10), and an upper electrode (26a, 26b) is arranged on the switching area (14a, 14b), and have a length that covers the two electrodes (18a and 18b, 20a and 20b) arranged on the underside (16), which are wired together as a series connection of two capacitors and are capacitively connected by the upper electrode (26a, 26b).

21. The contact switching arrangement in accordance with claim 20, wherein the upper electrode (26a, 26b) is made of a transparent material.

22. The contact switching arrangement in accordance with claim 1, wherein two electrodes (18a and 18b, 20a and 20b) are arranged next to each other on the underside (16) of the cover (10), which are connected with a switching arrangement (22) for generating an electrical alternating field (28a, 28b) which penetrates the cover (10) at least near the switching area (14a, 14b) and for detecting disturbances of the electrical alternating field (28a, 28b) in case of the approach of the finger of the user, or of a similar conducting body, to the switching area (14a, 14b).

23. The contact switching arrangement in accordance with claim 1, wherein the cover is made from the light-reflecting film (24).

24. The contact switching arrangement in accordance with claim 1, wherein the cover (10) is formed of a transparent plate (30), which has the switching area (14a, 14b) on the top (12) facing the user, and the light-reflecting film (24) on the underside (16) facing away from the user.

25. The contact switching arrangement in accordance with claim 1, wherein the cover (10) is formed by a non-conducting plate (30) which has the light-reflecting film (24) and the switching area (14a, 14b) on the top (12) facing the user.

26. The contact switching arrangement in accordance with claim 9, wherein the light-reflecting film (24) is applied to the transparent plate (30) by one of a lamination, a heat-seal, an adhesive and a fixed planar connection.

27. The contact switching arrangement in accordance with claim 9, wherein the transparent plate (30) is made of one of a glass, a plastic and a transparent material.

28. The contact switching arrangement in accordance with claim 1, wherein the light-reflecting film (24) has one of a smooth, a mirrored, and a structured surface, which reflects light in a diffuse manner.

29. The contact switching arrangement in accordance with claim 1, wherein the light-reflecting film (24) transmits light at least partially in a visible wavelength range.

30. The contact switching arrangement in accordance with claim 29, wherein at least one illuminated display (32a, 32b, 32c) is arranged on one of the underside (16) of the cover (10) and the light-reflecting film (24) facing away from the user.

31. The contact switching arrangement in accordance with claim 30, wherein the illuminated displays (32a, 32b, 32c) are formed by at least one of lamps, light-emitting diodes, self-illuminated graphic displays, 7-segment displays, backlit liquid crystal displays, backlit symbols and optical displays radiating through the light-reflecting film.

32. The contact switching arrangement in accordance with claim 1, wherein the position of the switching area (14a, 14b) is identified by at least one of a symbolic device and a similar marking ((34a, 34b, 34c, 34d) on at least one of the cover (10) and the light-reflecting film (24).

33. The contact switching arrangement in accordance with claim 1, wherein the light-reflecting film (24) is flexible, and the flat cover (10) at least in some areas is one of curved, angled and has shapes differing from a flat shape, at least in some areas.