Touch switches and practical applications therefor

• US 9,306,561 B2
• Filed: 07/02/2012
• Issued: 04/05/2016
• Est. Priority Date: 01/19/1999
• Status: Expired due to Term

• Current Assignee: Touchsensor Technologies LLC (Methode Electronics Incorporated)
• Original Assignee: Touchsensor Technologies LLC (Methode Electronics Incorporated)
• Inventors: Caldwell, David W., Oppor, Rick L., Gioiosa, Anthony V., Campbell, Robert B., Schreiber, Thomas M., Wadia, Bahar N., Mathews, Mark R., Mueller, Donald Charles, Eavenson, Daniel
• Primary Examiner(s): Amaya, Carlos
• Application Number:
  US13/540,250
• Publication Number:
  US 20120267964A1
• Time in Patent Office: 1,373 Days
• Field of Search: 307/112, 307/116, 307/139, 200/600
• US Class Current: 1/1
• CPC Class Codes: A47B 57/00 Cabinets, racks or shelf units, characterised by features for adjusting shelves or partitions shelf units with stackable uprights A47B87/00; details of cabinets, racks or shelf units in general A47B96/00; brackets adjustable in themselves A47B96/07
• CPC Class Codes: A47B 96/025 Shelves with moving elements, e.g. movable extensions or link elements cabinets, racks or shelf units enabling enlargement in height, length or depth A47B45/00
• CPC Class Codes: F25D 2325/022 Shelves made of glass or ceramic
• CPC Class Codes: F25D 2331/803 Bottles
• CPC Class Codes: F25D 25/02 by shelves
• CPC Class Codes: G09F 3/204 specially adapted to be attached to a shelf or the like
• CPC Class Codes: G09F 9/30 in which the desired character or characters are formed by combining individual elements panels comprising a number of electrodes in a single cell controlling light arriving from an independent light source, e.g. electro-optical or magneto-optical cell, G02F1/00
• CPC Class Codes: H03K 17/96 Touch switches specially adapted for electronic time-pieces with no moving parts G04G21/08
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9602 characterised by the type or shape of the sensing electrodes

Abstract

A touch switch apparatus emulating a mechanical switch includes a field effect sensor and an electric field stimulator mechanically associated with the field effect sensor. A field generation signal applied to the field effect sensor causes an electric field to be generated thereabout. The electric field stimulator can be moved between first and second positions with respect to the field effect sensor. When moved into proximity with the field effect sensor, the electric field stimulator disturbs the electric field. A detection circuit coupled to the field effect sensor detects and responds to the disturbance to the electric field.

Claims

1. A touch switch sensor apparatus comprising:

a first sensor electrode;

a first additional electrode in selectively variable capacitive relationship with said first electrode;

a signal source; and

a control circuit, said control circuit in the form of an integrated circuit in proximity to said first sensor electrode, said control circuit comprising;

an input section having a first input channel and a second input channel;

a decision section having a first input, a second input, and an output; and

an output section;

said first input channel coupled to said signal source, to said first sensor electrode, and to said first input of said decision section, said first input channel comprising as least one first input channel electrical component;

said second input channel coupled to said signal source and to said second input of said decision section, said second input channel comprising at least one second input channel electrical component, each of said second input channel electrical components corresponding to one of said first input channel electrical components; and

said output of said decision section coupled to said output section;

wherein each of said second input channel electrical component is electrically matched to the corresponding first input channel electrical component.

2. The apparatus of claim 1 wherein a first of said first input channel electrical components comprises a first transistor having an input terminal, an output terminal, and a control terminal;

said input terminal of said first transistor coupled to said signal source and to said first electrode; and

said output terminal of said first transistor coupled to said first input of said decision section; and

wherein a first of said second input channel electrical components comprises a second transistor having an input terminal, an output terminal, and a control terminal;

said input terminal of said second transistor coupled to said signal source and said output terminal of said second transistor coupled to said second input of said decision section.

3. The apparatus of claim 2 wherein at least one of said said first and said second input channels further comprises a peak detector circuit.

4. The apparatus of claim 3 wherein said peak detector circuit comprises a rectifier coupled to said output terminal of said first transistor and to said first input of said decision section and a capacitor coupled to said first rectifier and to said first input of said decision section.

5. The apparatus of claim 3 wherein said rectifier comprises a first diode.

6. The apparatus of claim 2 wherein at least one of said first and said second input channels further comprises a square root extractor.

7. The apparatus of claim 1 further comprising a second additional electrode in variable capacitive relationship with said first electrode.

8. The apparatus of claim 1 wherein said apparatus generates a decision section output signal at the output of said decision section, wherein said decision section output signal changes in response to a change in capacitance between said first sensor electrode and said first additional electrode.

9. The apparatus of claim 1 wherein the separation between said first sensor electrode projected against the surface area of said first additional electrode is selectively variable.

10. The apparatus of any claim 1 wherein the surface area of said first sensor electrode projected against the surface area of said first additional electrode is selectively variable.

11. The apparatus of claim 1 wherein said first sensor electrode and said first additional electrode are configured to selectively receive a first medium having a first dielectric constant and a second medium having a second dielectric constant therebetween.

12. The apparatus of claim 1 wherein said first additional electrode is coupled to an electrical ground.

13. The apparatus of claim 1 further comprising a second sensor electrode coupled to said second input channel, said first additional electrode further in selectively variable capacitive relationship with said second sesnor electrode.

14. The apparatus of claim 13 wherein a first of said first input channel electrical components comprises a first transistor having an input terminal, an output terminal, and a control terminal;

said input terminal of said first transistor coupled to said signal source and to said first electrode; and

said output terminal of said first transistor coupled to said first input of said decision section; and

wherein a first of said second input channel electrical components comprises a second transistor having an input terminal, an output terminal, and a control terminal;

said input terminal of said second transistor coupled to said signal source and to said second electrode; and

said output terminal of said second transistor coupled to said second input of said decision section.

15. The apparatus of claim 14 wherein at least one of said first and said second input channels further comprises a peak detector circuit.

16. The apparatus of claim 15 wherein said peak detector circuit comprises a rectifier coupled to said output terminal of said first transistor and to said first input of said decision section and a capacitor coupled to said first rectifier and to said first input of said decision section.

17. The apparatus of claim 16 wherein said rectifier comprises a first diode.

18. The apparatus of claim 13 wherein at least one of said first and said second input channels further comprises a square root extractor.

19. The apparatus of claim 13 further comprising a second additional electrode in variable capacitive relationship with said first sensor electrode and said second sensor electrode.

20. The apparatus of claim 19 wherein at least one of said first auxiliary additional electrode and said second additional electrode is coupled to an electrical ground.

21. The apparatus of claim 13 wherein said apparatus generates a decision section output signal at the output of said decision section in response to at least one of a change in capacitance between said first sensor electrode and said first additional electrode and a change in capacitance between said second sensor electrode and said first additional electrode.

22. The apparatus of claim 13 wherein the separation between said first sensor electrode projected against the surface area of said first additional electrode is selectively variable.

23. The apparatus of claim 13 wherein the surface area of said first sensor electrode projected against the surface area of said first additional electrode is selectively variable.

24. The apparatus of claim 13 wherein said first sensor electrode and said first additional electrode are configured to selectively receive a first medium having a first dielectric constant and a second medium having a second dielectric constant therebetween.