| 摘要 |
PURPOSE: A DC(Direct Current) based two lines video door phone system is provided to transmit and receive the data and digital image sound by utilizing the line of a door phone for a voice call. CONSTITUTION: A video door phone(200) connects to two lines of SMPS(100). The video door phone separately outputs digital data related to images or voice and DC power sources. The video door phone transmits digital data related to the images or the voice. An external terminal(300) connects to two lines of the SMPS. The external terminal separately outputs digital data related to the image or the voice, and the inputted DC power sources. The external terminal transmits the digital data related to the images or the voice. [Reference numerals] (200) Video door phone; (300) External terminal |
