Method of visible light communication using illuminance sensor and mobile communication terminal for the same

• US 9,276,677 B2
• Filed: 01/28/2015
• Issued: 03/01/2016
• Est. Priority Date: 07/12/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Son, Jae-Seung, Bae, Tae-Han, Won, Eun-Tae
• Primary Examiner(s): Phan, Hanh
• Application Number:
  US14/607,981
• Publication Number:
  US 20150139660A1
• Time in Patent Office: 398 Days
• Field of Search: 398/172, 398/118, 398/128, 398/130, 398/127, 398/129, 398/119, 398/120, 398/131, 398/115, 398/116, 398/117, 398/135, 398/136, 398/202, 398/208, 398/209
• US Class Current: 1/1
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04B 10/40 Transceivers
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

According to one embodiment, a photo detector-combined illuminance sensor includes a circuit for a Photo Detector (PD) function to detect the illuminance of the ambient environment. The illuminance sensor operates under the control of a controller in a visible light communication terminal. When an optical signal detected by the illuminance sensor is a visible light communication signal, the controller switches to cause the illuminance sensor to operate as the photo detector for the visible light communication in a visible light communication mode.

Claims

1. A method to perform a visible light communication in a mobile communication terminal, the method comprising:

receiving an optical signal and converting the optical signal to an electrical signal through a light receiving element; and

controlling the terminal to operate in one of a visible light communication mode and a illuminance measurement mode based on the signal output from the light receiving element.

2. The method of claim 1, further comprising:

measuring an illuminance in an optical data processor using the electrical signal converted by the light receiving element;

converting the illuminance value measured by the optical data processor to a current value;

amplifying the converted electrical signal in a low noise amplifier; and

removing DC noise from the amplified signal.

3. The method of claim 2, further comprising interconnecting the light receiving element and one of the low noise amplifier and the optical data processor.

4. The method of claim 3, wherein, when an operation mode of the terminal is in the illuminance measurement mode, interconnecting the light receiving element and one of the low noise amplifier and the optical data processor comprises interconnecting the light receiving element and the optical data processor to enable the electrical signal outputted from the light receiving element to be transferred to the optical data processor.

5. The method of claim 3, wherein, when an operation mode of the terminal is in the visible light communication mode, interconnecting the light receiving element and one of the low noise amplifier and the optical data processor comprises interconnecting the light receiving element and the low noise amplifier to enable the electrical signal outputted from the light receiving element to be transferred to the low noise amplifier.

6. The method of claim 2, further comprising controlling a brightness of a backlight of a display unit according to the converted current value.

7. The method of claim 1, wherein the light receiving element comprises a photo diode.

8. The method of claim 1, further comprising demodulating the signal output from the light receiving element to data based on a visible light communication scheme to determine whether the output signal is a visible light signal.

9. A method to perform for a visible light communication in a mobile communication terminal, the method comprising:

demodulating a signal outputted from an illuminance sensor based on a visible light communication scheme in a visible light communication mode; and

switching the visible light communication mode to an illuminance measurement mode to measure an illuminance by the illuminance sensor based on determining that the output signal does not correspond to a visible light communication signal.

10. The method of claim 9, wherein the signal outputted from the illuminance sensor in the visible light communication mode includes a signal obtained by converting an optical signal received through a light receiving element into an electrical signal, amplifying the converted electrical signal by a low noise amplifier, and removing DC noise from the amplified signal using a filter.

11. The method of claim 10, further comprising interconnecting the low noise amplifier to enable the electrical signal outputted from the light receiving element to be transferred to the low noise amplifier when the mobile communication terminal is in the visible light communication mode.

12. The method of claim 9, further comprising receiving an optical signal and converting the received optical signal to an electrical signal, wherein the illuminance sensor measures an illuminance using the electrical signal.

13. The method of claim 9, further comprising when the output signal corresponds to a visible light communication signal, controlling the illuminance sensor to operate the visible light communication mode.

14. The method of claim 9, further comprising controlling a brightness of a backlight of a display unit according to an illuminance measured by the illuminance sensor in the illuminance measurement mode.

15. A method to perform a visible light communication in a mobile communication terminal, method comprising:

receiving an optical signal;

converting the optical signal to an electrical signal;

outputting the converted electrical signal through a light receiving element; and

controlling an illuminance sensor to measure an illuminance based on determining that the outputted signal from the light receiving element is not a visible light communication signal.

16. The method of claim 15, further comprising:

measuring an illuminance in an optical data processor using the electrical signal converted by the light receiving element;

converting an illuminance value measured by the optical data processor to a current value;

amplifying the electrical signal in a low noise amplifier; and

removing DC noise from the amplified signal.

17. The method of claim 16, wherein the light receiving element comprises a photo diode.

18. The method of claim 16, further comprising interconnecting the light receiving element and the low noise amplifier to enable the electrical signal outputted from the light receiving element to be transferred to the low noise amplifier when an operation mode of the terminal is in the visible light communication mode.

19. The method of claim 16, further comprising interconnecting the light receiving element and the optical data processor to enable the electrical signal outputted from the light receiving element to be transferred to the optical data processor when an operation mode of the terminal is in the illuminance measurement mode.

20. The method of claim 16, further comprising interconnecting the light receiving element and the optical data processor when the output signal is not a visible light signal.

21. An electronic device to perform a visible light communication, the electronic device comprising:

a light receiving element configured to receive an optical signal and converting the optical signal to an electrical signal; and

a controller configured to determine whether the signal outputted from the light receiving element corresponds to a visible light communication signal, and to control the electronic device to operate in one of a visible light communication mode and a illuminance measurement mode for measuring an illuminance according to determined result.

22. The electronic device of claim 21, wherein further comprising:

an optical data processor configured to measure an illuminance using the electrical signal converted by the light receiving element;

an electric current amplifier configured to convert the illuminance value measured by the optical data processor to a current value;

a low noise amplifier configured to amplify the converted electrical signal in a low noise amplifier; and

a filter configured to remove DC noise from the amplified signal.

23. The electronic device of claim 22, wherein the light receiving element comprises a photo diode.

24. The electronic device of claim 22, further comprising a selector configured to interconnect the light receiving element and one of the low noise amplifier and the optical data processor according to the determined result.

25. The electronic device of claim 24, wherein, when an operation mode of the electronic device is in the illuminance measurement mode, the controller is configured to control the selector to interconnect the light receiving element and the optical data processor to enable the electrical signal outputted from the light receiving element to be transferred to the optical data processor.

26. The electronic device of claim 24, wherein, when an operation mode of the electronic device is in the visible light communication mode, the controller is configured tocontrol the selector to interconnect the light receiving element and the low noise amplifier to enable the electrical signal outputted from the light receiving element to be transferred to the low noise amplifier.

27. The electronic device of claim 21, wherein the controller is configured to demodulate the signal outputted from the light receiving element to data based on a visible light communication scheme to determine whether the output signal is a visible light signal.

28. The electronic device of claim 21, further wherein the controller is configured to control brightness of a backlight of a display unit according to the converted current value.

29. An electronic device to perform a visible light communication, the electronic device comprising:

an illuminance sensor; and

a controller configured to;

demodulate a signal outputted from the illuminance sensor based on a visible light communication scheme in a visible light communication mode, and

switch the visible light communication mode to an illuminance measurement mode to measure an illuminance by the illuminance sensor based on determining that the output signal does not correspond to a visible light communication signal.

30. The electronic device of claim 29, wherein the signal outputted from the illuminance sensor in the visible light communication mode includes a signal obtained by converting an optical signal received through a light receiving element into an electrical signal, amplifying the converted electrical signal by a low noise amplifier, and removing DC noise from the amplified signal using a filter.

31. The electronic device of claim 30, wherein the light receiving element is interconnected to the low noise amplifier to enable the electrical signal outputted from the light receiving element to be transferred to the low noise amplifier when the electronic device is in the visible light communication mode.

32. The electronic device of claim 31, wherein, when the output signal corresponds to a visible light communication signal, the controller is configured to control the illuminance sensor to operate the visible light communication mode.

33. The electronic device of claim 29, further comprising:

a light receiving element configured to receive an optical signal and converting the received optical signal to an electrical signal, wherein the electrical signal outputted from the illuminance sensor is used to measure an illuminance.

34. The electronic device of claim 29, wherein the controller is configured to control a brightness of a backlight of a display unit according to an illuminance determined using the illuminance sensor in the illuminance measurement mode.