Light emitting device and communication system

1. A light-emitting device, comprising:

at least one driver unit for generating a modified current based on an externally entered information signal; and

at least one light-emitting unit operatively and functionally coupled to said at least one driver unit for receiving said modified current and emitting a modified signal light, said modified signal light comprising a modification of a non-signal illumination light, said modification comprising an optical signal that corresponds to said externally entered information signal,

wherein said modified signal light and said non-signal illumination light are emitted at different time periods, said modified signal light not causing perceptible flickering illumination light,

wherein said at least one light-emitting unit comprises at least one electroluminescence element and first and second light-emitting unit groups, the first light emitting unit group being capable of emitting said non-signal illumination light and the second light emitting unit group being capable of emitting said modified signal light,

wherein said at least one driver unit comprises a first driver unit electrically coupled to said first light-emitting unit group for supplying said first light-emitting unit group with a first modified current upon entry of said externally entered information signal or a first non-modified current upon non-entry of any information signal and a second driver unit electrically coupled to said second light-emitting unit group for supplying said second light-emitting unit group with a second modified current upon entry of said externally entered information signal or a second non-modified current upon non-entry of any information signal,

wherein said first and second light-emitting unit groups are electrically coupled in opposite polarities to each other to an AC-power supply, and

each of said first and second light-emitting unit groups emits said modified signal light and said non-signal illumination light alternately.

2. The light-emitting device as claimed in claim 1 , wherein said at least one light-emitting unit receives a non-modified current and emits said non-signal illumination light free of any information when said at least one driver unit generates the non-modified current upon no entry of any externally entered information signal.

3. The light-emitting device as claimed in claim 1 , further comprising:

at least one secondary light-emitting unit operatively and functionally separated from said at least one driver unit and also from said at least one light-emitting unit for emitting a non-signal illumination light free of any information.

4. The light-emitting device as claimed in claim 3 , wherein said at least one light-emitting unit receives a non-modified current and emits a non-signal illumination light free of any information when said at least one driver unit generates the non-modified current upon no entry of any externally entered information signal.

5. The light-emitting device as claimed in claim 1 , wherein at least one group of said first and second light-emitting unit groups comprises a plurality of light-emitting elements, some of which are connected in series to each other.

6. A communication system, comprising:

at least one light-emitting device for emitting a light; and

at least one light-receiving device for receiving said light coming from said at least one light-emitting device,

said at least one light-emitting device further comprising:

at least one driver unit for generating a modified current based on an externally entered information signal; and

at least one light-emitting unit operatively and functionally coupled to said at least one driver unit for receiving said modified current and emitting a modified signal light, said modified signal light comprising a modification of a non-signal illumination light, said modification comprising an optical signal that corresponds to said externally entered information signal,

wherein said modified signal light and said non-signal illumination light are emitted at different time periods, said modified signal light not causing perceptible flickering illumination light, and

wherein said at least one light-emitting unit comprises at least one electroluminescence element and first and second light-emitting unit groups, the first light-emitting unit group being capable of emitting said non-signal illumination light and the second light-emitting unit group being capable of emitting said modified signal light,

wherein said at least one driver unit comprises a first driver unit electrically coupled to said first light-emitting unit group for supplying said first light-emitting unit group with a first modified current upon entry of said externally entered information signal or a first non-modified current upon non-entry of any information signal and a second driver unit electrically coupled to said second light-emitting unit group for supplying said second light-emitting unit group with a second modified current upon entry of said externally entered information signal or a second non-modified current upon non-entry of any information signal,

wherein said first and second light-emitting unit groups are electrically coupled in opposite polarities to each other to an AC-power supply, and

each of said first and second light-emitting unit groups emits said modified signal light and said non-signal illumination light alternately.

7. The communication system as claimed in claim 6 , wherein said at least one light-emitting unit receives a non-modified current and emits said non-signal illumination light free of any information when said at least one driver unit generates the non-modified current upon no entry of any externally entered information signal.

8. The communication system as claimed in claim 6 , further comprising:

at least one secondary light-emitting unit operatively and functionally separated from said at least one driver unit and also from said at least one light-emitting unit for emitting a non-signal illumination light free of any information.

9. The communication system as claimed in claim 8 , wherein said at least one light-emitting unit receives a non-modified current and emits said non-signal illumination light free of any information when said at least one driver unit generates the non-modified current upon no entry of any externally entered information signal.

10. The communication system as claimed in claim 6 , wherein at least one group of said first and second light-emitting unit groups comprises a plurality of light-emitting elements, some of which are connected in series to each other.

11. The communication system as claimed in claim 6 , wherein said at least one light-receiving device further comprises:

at least one light-receiving element for receiving said modified signal light emitted from said at least one light-emitting device and converting said modified signal light into an electric signal.

12. The communication system as claimed in claim 6 , wherein said at least one light-receiving device further comprises:

at least one light-receiving element for receiving said modified signal light emitted from said at least one light-emitting device and converting said modified signal light into an electric signal; and

at least one signal converter unit electrically coupled to said at least one light-receiving element for converting said electric signal into data.

13. The communication system as claimed in claim 6 , wherein said at least one light-receiving device further comprises:

at least one light-receiving element for receiving said modified signal light emitted from said at least one light-emitting device and converting said modified signal light into an electric signal;

at least one signal converter unit electrically coupled to said at least one light-receiving element for converting said electric signal into data; and

at least one storage unit electrically coupled to said at least one signal converter unit for storing said data.

14. The communication system as claimed in claim 13 , wherein said at least one light-receiving device is provided on an object for serving as an information tag.

15. The communication system as claimed in claim 6 , wherein said at least one light-receiving device further comprises:

at least one light-receiving element for receiving said modified signal light emitted from said at least one light-emitting device and converting said modified signal light into an electric signal;

at least one signal converter unit electrically coupled to said at least one light-receiving element for converting said electric signal into data;

at least one storage unit electrically coupled to said at least one signal converter unit for storing said data; and

at least one information output unit electrically coupled to said at least one storage unit for receiving said data and displaying information based on said data.

16. The communication system as claimed in claim 6 , wherein said at least one light-receiving device receives said modified signal light emitted from said at least one light-emitting device and converts said modified signal light into an electric signal, and said at least one light-receiving device is electrically coupled to an equipment for supplying said electric signal and controlling said equipment based on said electric signal.