LOW RESISTANCE SWITCH USING CARBON CONTACTS

• US 20010052729A1
• Filed: 11/12/1999
• Published: 12/20/2001
• Est. Priority Date: 11/12/1999
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: TURNBULL, ROBERT R., POE, G. BRUCE, BONARDI, TIMOTHY A.
• Granted Patent: US 6,426,568 B2
• Time in Patent Office: Days
• US Class Current: 307/10.1
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 2201/026 non precious
• CPC Class Codes: H01H 2201/032 Conductive polymer; Rubber
• CPC Class Codes: H01H 2239/012 Decoding impedances
• CPC Class Codes: H01H 2300/012 Application rear view mirror
• CPC Class Codes: H01H 9/547 Combinations of mechanical switches and static switches, the latter being controlled by the former

Abstract

A switch assembly includes a plurality of electrical devices and a plurality of user activated switches. The plurality of electrical devices each include a control terminal. Each of the electrical devices causes a different distinguishable output to be provided when a control signal is asserted on the control terminal of one of the plurality of electrical devices. The plurality of user activated switches include carbon-coated contacts. Each of the user activated switches when asserted provides the control signal to the control terminal of one of the plurality of electrical devices.

Claims

1. A switch assembly, comprising:

a plurality of electrical devices each including a control terminal, each of the plurality of electrical devices causing a different distinguishable output to be provided when a control signal is asserted on the control terminal of one of the plurality of electrical devices; and

a plurality of user activated switches with carbon-coated contacts, each of the user activated switches when asserted providing the control signal to the control terminal of one of the plurality of electrical devices.

2. The switch assembly of

claim 1

, wherein the user activated switches include:

an elastomer;

a carbon coated contact attached to the elastomer at a contact area;

a printed circuit board including a first copper trace and a second copper trace, wherein the first and second copper traces each include carbon-coated contacts at the contact area,

wherein the elastomer prevents the carbon-coated contact attached to the elastomer from making electrical contact with the carbon-coated contacts of the first and second copper traces unless a user applies an adequate force to the elastomer.

3. The switch assembly of

claim 1

, wherein the electrical devices are field effect transistors.

4. The switch assembly of

claim 1

, wherein the electrical devices are bipolar junction transistors.

5. The switch assembly of

claim 1

, wherein a processor monitors the plurality of user activated switches and provides the control signal to one of the plurality of electrical devices upon switch assertion.

6. A rearview mirror assembly for a vehicle comprising:

a housing having a mounting member for mounting said housing to the vehicle, said housing including a bezel;

an electrochromic mirror disposed in said housing, said mirror having a front surface and a rear surface; and

a switch assembly retained in said housing including;

a plurality of electrical devices each further including a control terminal, each of the plurality of electrical devices causing a different distinguishable output to be provided when a control signal is asserted on the control terminal of one of the plurality of electrical devices; and

a plurality of user activated switches with carbon-coated contacts, each of the user activated switches when asserted providing the control signal to the control terminal of one of the plurality of electrical devices.

7. The rearview mirror assembly of

claim 6

, wherein said electrochromic mirror comprises:

front and rear spaced elements, each having front and rear surfaces and being sealably bonded together in a spaced-apart relationship to define a chamber;

a transparent first electrode including a layer of transparent conductive material carried on said rear surface of said front element;

at least one electrochromic material contained within said chamber; and

a second electrode disposed on said front surface of said rear element, wherein either said second electrode is a reflective electrode or a transparent electrode with a corresponding separate reflector disposed over substantially all of said rear surface of said rear element.

8. The rearview mirror assembly of

claim 6

, wherein the switch assembly further includes:

an elastomer;

a carbon coated contact attached to the elastomer at a contact area;

a printed circuit board including a first copper trace and a second copper trace, wherein the first and second copper traces each include carbon-coated contacts at the contact area,

wherein the elastomer prevents the carbon-coated contact attached to the elastomer from making electrical contact with the carbon-coated contacts of the first and second copper traces unless a user applies an adequate force to the elastomer.

9. The rearview mirror assembly of

claim 6

, wherein the electrical devices are field effect transistors.

10. The rearview mirror assembly of

claim 6

, wherein the electrical devices are bipolar junction transistors.

11. The rearview mirror assembly of

claim 6

, wherein a processor monitors the plurality of user activated switches and provides the control signal to one of the plurality of electrical devices upon switch assertion.