Touch switch for electrical appliances and electrical appliance provided with such switch

• US 7,915,553 B2
• Filed: 03/09/2010
• Issued: 03/29/2011
• Est. Priority Date: 10/08/2007
• Status: Active Grant

• Current Assignee: Whirlpool Corporation
• Original Assignee: Whirlpool Corporation
• Inventors: Lazzarotto, Roberto, Braghini, Giorgio, Arena, Giuseppe, Arione, Ettore
• Primary Examiner(s): Luebke; Renee
• Assistant Examiner(s): CAROC, LHEIREN MAE ANGLO
• Application Number:
  US12/719,887
• Publication Number:
  US 20100155206A1
• Time in Patent Office: 385 Days
• Field of Search: 200/314
• US Class Current: 200/314
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/960755 Constructional details of capacitive touch and proximity switches
• CPC Class Codes: H03K 2217/96076 with spring electrode
• CPC Class Codes: H03K 2217/96079 using a single or more light guides

Abstract

A touch switch for an electrical appliance having a capacitive flat electrode, a light source, a transparent cover and a printed circuit board connected to the electrode is disclosed. The light source is mounted on a face of the printed circuit board opposite the transparent cover and the printed circuit board presents a cut-out for allowing light transmission from the light source towards the transparent cover.

Claims

1. A capacitive touch switch for an appliance comprising:

a non-conductive transparent cover;

a printed circuit board below the non-conductive transparent cover, said printed circuit board including a first side, an opposing second side and a cut-out portion;

an electrode mounted on the second side of the printed circuit board adjacent the cut-out portion and opposite the non-conductive transparent cover; and

a light source mounted across the cut-out portion with an air gap being maintained between the light source and the transparent cover, and the light emitted by the light source being directed through the cut-out portion of the printed circuit board towards the non-conductive transparent cover.

2. The capacitive touch switch of claim 1, wherein the light source is mounted on the second side of the printed circuit board.

3. The capacitive touch switch of claim 1, further comprising:

a capacitive flat sensor portion provided on the non-conductive transparent cover.

4. The capacitive touch switch of claim 1, further comprising:

a second electrode mounted on the second side of the printed circuit board adjacent the cut-out portion and opposite the non-conductive transparent cover.

5. The capacitive touch switch of claim 1, wherein the light source is a seven-segment display.

6. The capacitive touch switch of claim 1, wherein the light source is a reverse-mounted LED.

7. The capacitive touch switch of claim 1, wherein the printed circuit board is fixed to the non-conductive transparent cover by a non-conductive adhesive.

8. The capacitive touch switch of claim 1, further comprising:

an auxiliary layer interposed between the non-conductive transparent cover and the printed circuit board, the auxiliary layer having a transparent zone through which the light from the light source is directed.

9. The capacitive touch switch of claim 8, further comprising:

an opaque icon provided at the transparent zone of the auxiliary layer.

10. The capacitive touch switch of claim 8, wherein the auxiliary layer is a light filtering polymeric film.

11. The capacitive touch switch of claim 1, further comprising:

metal pins fixing the light source to the printed circuit board.