System and method to prevent cross-talk between a transmitter and a receiver

• US 20060016994A1
• Filed: 07/22/2004
• Published: 01/26/2006
• Est. Priority Date: 07/22/2004
• Status: Abandoned Application

• Current Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Tan, Wee Sin, Ng, Peng Yam, Basoor, Suresh, Loong, Wong Chiap
• Application Number:
  US10/896,829
• Publication Number:
  US 20060016994A1
• Time in Patent Office: Days
• US Class Current: 250/338.100
• CPC Class Codes: G01V 8/12 using one transmitter and one receiver
• CPC Class Codes: H03K 17/941 using an optical detector H03K17/968 takes precedence
• CPC Class Codes: H03K 17/9631 using a light source as part of the switch
• CPC Class Codes: H03K 2217/94108 making use of reflection
• CPC Class Codes: H03K 2217/96015 Constructional details for touch switches

Abstract

According to at least one embodiment of the invention, a method includes mounting a transmitting device and a receiving device on a circuit board, wherein the circuit board includes a layer that blocks waves (e.g., light waves) emitted from the transmitting device, and wherein the transmitting device and the receiving device are mounted in an area defined by the layer. The method further includes manipulating a structure to form a first compartment for the transmitting device and a second compartment for the receiving device, wherein the compartments are separated by a common wall such that each compartment is continuous with at least part of the common wall. The method further comprises mounting the structure on the circuit board. According to this embodiment, the transmitter and the receiver may be part of a proximity sensor, and the layer that blocks waves, the first and second compartments, and the common wall (which may be a folded double wall) operate to prevent cross-talk between the transmitter and the receiver.

Claims

1. A method comprising:

mounting a transmitting device and a receiving device on a substrate, wherein the substrate includes a layer that blocks waves emitted from the transmitting device, and wherein the transmitting device and the receiving device are mounted in an area defined by the layer;

manipulating a structure to form a first compartment for the transmitting device and a second compartment for the receiving device, wherein the compartments are separated by a common wall, and wherein each compartment is continuous with at least part of the common wall; and

mounting the structure on the substrate.

2. The method of claim 1 wherein the substrate is a circuit board.

3. The method of claim 1 wherein the structure is made of a single piece of material.

4. The method of claim 1 wherein the common wall is a folded double wall.

5. The method of claim 1 wherein mounting the structure is performed before mounting the transmitting and receiving devices.

6. The method of claim 1 wherein manipulating the structure comprises bending the structure.

7. The method of claim 1 further comprising operating the transmitting device and the receiving device as a proximity sensor.

8. The method of claim 7 further comprising employing the proximity sensor in a water faucet.

9. The method of claim 1 wherein mounting the structure comprises aligning the structure so that its footprint is within the area defined by the layer.

10. The method of claim 1 wherein the layer comprises a metallic layer or a soldermask layer.

11. The method of claim 1 wherein the layer blocks waves from direct communication with the receiving device.

12. The method of claim 1 wherein the transmitting device and the receiving device are in a single package and are coupled to one another, such that mounting the transmitting device and the receiving device on a circuit board comprises mounting a single transmitter/receiver unit.

13. An apparatus comprising:

a transmitter;

a receiver; and

a Printed Circuit Board (PCB), wherein the PCB includes a layer of material that blocks wireless communication from the transmitter, and wherein the transmitter and receiver are mounted on the PCB in an area defined by the layer.

14. The apparatus of claim 13 wherein the layer of material comprises a liquid soldermask.

15. The apparatus of claim 13 wherein the layer of material comprises one or more metallic layers.

16. The apparatus of claim 15 wherein at least one metallic layer comprises copper.

17. The apparatus of claim 13 wherein wireless communication is infrared waves.

18. The apparatus of claim 13 wherein the transmitter and receiver are part of a single-piece proximity sensor.

19. The apparatus of claim 13 further comprising a shield mounted on the PCB in the area defined by the layer of material.

20. The apparatus of claim 19 wherein the transmitter, the receiver, the PCB, and the shield are included in a proximity sensor unit.

21. An apparatus comprising:

two compartments;

a common wall separating the two compartments, wherein the each compartment is continuous with at least part of the common wall;

a transmitter, wherein the transmitter is substantially within a volume defined by one of the compartments; and

a receiver, wherein the receiver is substantially within a volume defined by the other compartment.

22. The apparatus of claim 21 wherein the transmitter, the receiver, and the compartments are mounted on a Printed Circuit Board (PCB).

23. The apparatus of claim 22 wherein the PCB includes a layer that blocks waves emitted from the transmitter.

24. The apparatus of claim 23, wherein the compartments and the layer are operable to prevent cross-talk between the transmitter and the receiver.

25. The apparatus of claim 21 wherein the compartments comprise a single piece of material, and wherein the compartments and the common wall are formed by bending the piece of material.

26. The apparatus of claim 21 wherein the compartments comprise stainless steel.

27. The apparatus of claim 21 wherein each of the two compartments includes an aperture.

28. The apparatus of claim 21 wherein the common wall is a folded double wall.

29. A method comprising:

operating a transmitter, wherein the transmitter is located in a first compartment, wherein a receiver is located in a second compartment separated from the first compartment by a wall structure, and wherein each compartment is continuous with at least part of the wall structure; and

blocking, by the compartments and a layer in a substrate, waves from the transmitter, thereby preventing cross-talk.

30. The method of claim 29, wherein the wall structure is a folded double wall structure.

31. The method of claim 29, wherein the substrate is a Printed Circuit Board (PCB), the layer is a copper layer, and the compartments are mounted on the PCB.

32. The method of claim 29 wherein the transmitter and receiver are operated as a proximity sensor.

33. A system for preventing cross-talk between a transmitter and a receiver comprising:

means for separating the transmitter and receiver with a common wall; and

means for mounting the transmitter, the receiver, and the means for separating the transmitter and the receiver on a Printed Circuit Board (PCB), wherein the PCB includes a layer that blocks electromagnetic waves emitted by the transmitter.

34. The system of claim 33 wherein the means for separating the transmitter and receiver comprise a structure, wherein the common wall is a folded double wall that is part of the structure, wherein the structure includes a first compartment for the transmitter and a second compartment for the receiver, and wherein the double wall is continuous with each of the compartments.

35. The system of claim 34, wherein the compartments, the folded double wall, and the layer surround each of the transmitter and receiver, except for an aperture for each of the transmitter and receiver, thereby preventing cross-talk.