US 5,822,099 A · Light communication system

Abstract

A light communication system employing light, such as infrared rays, in which power consumption required for light communication is diminished for prolonging the service life of portable equipments and for reducing interference or obstruction affecting other spatial light communication operations. A light emitting element 17 in a transmission portion 13 of a first transmission/reception device 10 is controlled in light emission by a light emission driving control circuit 12 and has its light emission intensity adjusted by a light emission intensity adjustment circuit 18 in a light emission drive control circuit 12. The light reception intensity in a light receiving element 27 of a receiving portion 24 of a second transmission/reception device 20 is detected by a reception light intensity detection circuit 28 in a light signal reception processing circuit 25 and sent via a transmission driving control circuit 22 and a transmitting portion 23 so as to be received by a reception portion 14 of the first transmission/reception device 10. The reception light intensity information is taken out by a reception processing circuit 15 and supplied to the light emission intensity adjustment circuit 18. The light emission intensity adjustment circuit 18 is responsive to the reception light intensity information to adjust the light emitting element 17 to a light emission intensity which is of a necessary minimum value to permit stable light communication.

Claims14

Dependent claims

An optical communication system comprising:

first transmitting and receiving circuitry and second transmitting and receiving circuitry, said first transmitting and receiving circuitry comprising:
a first transmitter portion having a first optical emitter;
a first receiving portion for receiving a transmission from said second transmitting and receiving circuitry;
adjustment circuitry for adjusting an optical emission intensity of an optical light emitted from said first optical emitter to said second transmitting and receiving circuitry;
and
said second transmitting and receiving circuitry comprising:
a second receiving portion having a second optical receiver;
an optical intensity detector for detecting an optical intensity of an optical light received from said first transmitting and receiving circuitry at said second optical receiver;
a second transmitting portion coupled to said second receiving portion for transmitting information of optical intensity detected by said optical intensity detector to said first transmitting and receiving circuitry;
wherein said adjustment circuitry adjusts said optical intensity emitted from said first optical emitter to said first transmitting and receiving circuitry in relation to said information of said optical intensity detected by said optical intensity detector.

7 more elements

An optical communication system comprising:

first transmitting and receiving circuitry and second transmitting and receiving circuitry, said first transmitting and receiving circuitry comprising:
a first transmitting portion having a first optical emitter directivity variable;
a first receiving portion for receiving a transmission from said second transmitting and receiving circuitry;
directivity control circuitry for controlling said directivity of said first optical emitter to said second transmitting and receiving circuitry;
and
said second transmitting and receiving circuitry comprising:
a second receiving portion having a second optical receiver;
an optical intensity detector for detecting an optical intensity of an optical light received from said first transmitting and receiving circuitry at said second optical receiver;
a second transmitting portion for transmitting to said first transmitting and receiving circuitry information related to said optical intensity detected by said optical intensity detector;
wherein said directivity control circuitry controls said directivity of said first optical emitter in relation to said information of said optical intensity detected by said optical intensity detector.

7 more elements

Dependencies are inferred from the claim text.

Light communication system

Life of this patent

Light communication system

Life of this patent

Abstract

Claims14