Method and apparatus for improving noise immunity for low intensity optical communication

• US 7,321,732 B2
• Filed: 07/28/2003
• Issued: 01/22/2008
• Est. Priority Date: 07/28/2003
• Status: Active Grant

• Current Assignee: Alcan Packaging Capsules, Nidec Motor Corporation (Nidec Corporation)
• Original Assignee: Emerson Electric Company
• Inventors: Astrauskas, Jurgis
• Primary Examiner(s): TRAN, DZUNG D
• Application Number:
  US10/628,765
• Publication Number:
  US 20050025494A1
• Time in Patent Office: 1,639 Days
• Field of Search: 398135-139, 398 63-165, 398/201, 398/130
• US Class Current: 398/138
• CPC Class Codes: A47L 15/4293 Arrangements for programme selection, e.g. control panels; Indication of the selected programme, programme progress or other parameters of the programme, e.g. by using display panels
• CPC Class Codes: D06F 2103/16 Washing liquid temperature
• CPC Class Codes: D06F 2105/02 Water supply
• CPC Class Codes: D06F 2105/42 Detergent or additive supply
• CPC Class Codes: D06F 2105/58 Indications or alarms to the control system or to the user
• CPC Class Codes: D06F 34/32 characterised by graphical features, e.g. touchscreens
• CPC Class Codes: H04B 10/40 Transceivers

Abstract

An optical communication probe enables a diagnostic tool to optically communicate with an external device, such as an appliance, through a low intensity indicator light of the external device. The communication probe includes an optical transmitter, an optical receiver, and a housing in which the optical transmitter and optical receiver are mounted. The optical transmitter transmits light signals having a logical polarity that is the opposite of an indicator light associated with an indicator light of an external device with which the optical transmitter is communicating. Use of the opposite logical polarity improves the noise immunity for the optical communication between the communication probe and the external device.

Claims

1. A probe for bi-directional optical communication with a device external to the probe, the probe comprising:

a housing;

an optical transmitter mounted within the housing that generates a light signal having a logical polarity that is the opposite of the logical polarity of the light signal generated by an indicator light associated with an external device with which the communication probe is communicating; and

an optical receiver mounted within the housing for receiving the light signal generated by the indicator light and generating an electrical data signal from the received light signal.

2. The probe of claim 1, wherein the optical transmitter mounted within the housing is a light emitting diode (LED) and the optical receiver is a phototransistor.

3. The probe of claim 2, wherein the LED is a standard LED.

4. The probe of claim 2, wherein the LED generates an intense light pulse.

5. The probe of claim 2, wherein the phototransistor is a sensitive phototransistor.

6. The probe of claim 1 further comprising:

a coupler for securing the housing to an external device so the optical transmitter and the optical receiver are in close proximity to the external device to enable optical communication with at least one low intensity indicator light of the external device.

7. A method for bi-directional optical communication, the method comprising:

generating a light signal having a logical polarity that is the opposite of the logical polarity of the light signal generated by an indicator light associated with an external device; and

receiving a light signal generated by the indicator light and generating an electrical data signal from the received light signal.

8. The method of claim 7, wherein the generated light of the light signal represents a logical ‘

1’ and

the light of the received light signal represents a logical ‘

0’

.

9. The method of claim 7, wherein the generated light of the light signal represents a logical ‘

0’ and

the light of the received light represents a logical ‘

1’

.