发明名称 |
Digital signal control system in a facsimile communication |
摘要 |
In a digitalized facsimile transmission system, (k) number of scanning lines (k=2 or 4) are encoded to a relative address code and the next scanning line is encoded to a run length code, and each scanning line has the related synchronization code pattern corresponding either said relative address code or said run length code. Thus, the effect of a transmission error is restricted within one scanning line when that error occurs in the scanning line encoded to run length code, or k lines when that error occurs in the scanning line encoded to relative address code. The value (k) is switched between k=2 and k=4 according to the instantaneous quality of a communication line. When the quality is good, k=4 is selected, and when the quality is bad, k=2 is selected. The reception side can switch the decoding systems between relative address decode and run length decode, by being controlled through the related synchronization code patterns. A synchronization code pattern has a plurality of O's inserted between a pair of 1's (1000 . . . 0001), and the number of O's between said 1's indicates one of relative address code and run length code. In order to discriminate a facsimile information from a synchronization code pattern, when the facsimile information has the more continuous O's than (n), an idle signal having the value "1" is inserted in every (n-1) number of continuous O's of the facsimile information. Said idle signal is deleted automatically in the receiver.
|
申请公布号 |
US4296439(A) |
申请公布日期 |
1981.10.20 |
申请号 |
US19800150100 |
申请日期 |
1980.05.15 |
申请人 |
KOKUSAI DENSHIN DENWA CO., LTD. |
发明人 |
TERAMURA, HIROICHI;YAMAZAKI, YASUHIRO;WAKAHARA, YASUSHI;HATTORI, NAOHIKO;YAMAMOTO, SEIICHI;NAKAO, KOUZO |
分类号 |
H04N1/32;H04L7/00;H04L7/08;H04L29/06;H04N1/333;H04N1/413;(IPC1-7):H04N7/12 |
主分类号 |
H04N1/32 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|