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

• US 20050025494A1
• Filed: 07/28/2003
• Published: 02/03/2005
• Est. Priority Date: 07/28/2003
• Status: Active Grant

• Current Assignee: Nidec Motor Corporation (Nidec Corporation), Alcan Packaging Capsules (Rio Tinto Limited)
• Original Assignee: Alcan Packaging Capsules (Rio Tinto Limited)
• Inventors: Astrauskas, Jurgis
• Granted Patent: US 7,321,732 B2
• Time in Patent Office: Days
• US Class Current: 398/140
• 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 light pulses in accordance with an electrical data signal, the optical transmitter being operated not to generate a light pulse in the absence of the electrical data signal; and

an optical receiver mounted within the housing that generates an electrical data signal from an optical signal impinging upon the optical receiver, the optical receiver receiving a continuous light signal from an external device in the absence of a data signal at the external device.

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 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.

8. The probe of claim 7, wherein the optical transmitter mounted within the housing is a light emitting diode (LED) and the optical receiver is a phototransistor.

9. The probe of claim 8, wherein the LED is a standard LED.

10. The probe of claim 8, wherein the LED generates an intense light pulse.

11. The probe of claim 8, wherein the phototransistor is a sensitive phototransistor.

12. The probe of claim 7 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.

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

generating light pulses in accordance with an electrical data signal except no light pulses are generated in the absence of the electrical data signal; and

receiving a continuous light signal from an external device in the absence of a data signal at an external device.

14. The method of claim 13 further comprising:

securing an optical transmitter in close proximity to an external device to enable optical communication through the generated light pulses.

15. 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.

16. The method of claim 15, wherein the generated light of the light signal represents a logical ‘

1’ and

the light of the received light signal represents a logical ‘

0’

.

17. The method of claim 15, wherein the generated light of the light signal represents a logical ‘

0’ and

the light of the received light represents a logical ‘

1’

.

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

generating light pulses in accordance with an electrical data signal except a continuous light pulse is generated in the absence of the electrical data signal; and

receiving no light signal from an external device in the absence of a data signal at an external device.

19. The method of claim 18 further comprising:

securing an optical transmitter in close proximity to an external device to enable optical communication through the generated light pulses.

20. The method of claim 18 wherein the logical polarity of the generated light and the received light is the same.