| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable a receiving side to easily reproduce a synchronizing signal by sending transmission frames in a fixed cycle. <P>SOLUTION: The intercom system is provided with: one or more multiple dwelling entrance slave units 10a, 10b, 10c-10m for performing calling operation, imaging and speech in a multiple dwelling entrance of a multiple dwelling house; a plurality of living room master units 20a, 20b, 20c-20n for performing picked-up image display and speech; and a control device 30 for performing voice and image exchange control in the case of speech. When transmitting a transmission frame (f) containing intercom control data d1, voice data d2 in a frame term of a fixed cycle between a slave unit and a master unit, in order to rightly transport a voice and image data sampling term T1 and a single-picture term T2 from the control device to the master unit, the relationship of the sampling term, the single-picture term and the frame term is set to 1:1, and a synchronizing marker M indicating a synchronism extraction position is added into the voice and image data. <P>COPYRIGHT: (C)2007,JPO&INPIT |
