Title:
OPTICAL COMMUNICATION METHOD AND ITS SYSTEM
Document Type and Number:
Japanese Patent JP3467198
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To minimize influence or other optical communication in the case of conducting optical communication.
SOLUTION: In the case of conducting infrared ray optical communication by using a subcarrier DC light is added and emitted for a time period T1 where no subcarrier is in existence. The power to drive a light emitting element to stimulate the DC light is equal to the power to drive the light emitting element for a time period T0 where the subcarrier is in existence. Since the light emitting element is driven to emit the DC light in the absence of the subcarrier by the same power when the subcarrier is in existence a base band spectrum with a lower frequency not required for data communication can be reduced. An undesired spectrum spread vertically to the subcarrier and the undesired harmonic spectrum can be reduced by unsharpening the changing moment of the DC light emitted additively or unsharpening the subcarrier or forming it to be a sine wave.
Inventors:
Seiichi Yokokawa
Application Number:
JP824099A
Publication Date:
November 17, 2003
Filing Date:
January 14, 1999
Export Citation:
Assignee:
Sharp Corporation
International Classes:
H03M5/20; H04B10/11; H04B10/116; H04B10/524; H04B10/54; H04B10/564; H04L27/06; (IPC1-7): H04B10/10; H03M5/20; H04B10/105; H04B10/22; H04L27/06
Domestic Patent References:
| JP8288818A | ||||
| JP3157979A | ||||
| JP8148979A | ||||
| JP4119025A |
Attorney, Agent or Firm:
Keiichiro Saikyo
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