| 摘要 |
An additional information produced by an additional information signal producing means (34) is spectrum-spread (35) by a spectrum spreading code generated on the basis of the timing (33) of the synchronous signal of digital video signal and is then added to the digital video signal by means of a signal adding means (32). The digital video signal to which the spectrum spread additional information signal is added is then written into a recording medium (300) by a signal writing means (36). Thereby, the additional information signal can be added to the video signal under the condition that the reproducing quality of the video signal is never deteriorated and alteration and deletion are impossible and moreover the additional information signal can be detected for use as required from the video signal. <IMAGE> |
