| 摘要 |
A video telephone for transmitting video data of a still picture through an audio signal line includes an image pickup tube for picking up a picture of the still picture, an A/D (analog-to-digital) converter for converting the analog output picked up by the image pick-up tube to the form of a digital signal, a memory for storing the output of the A/D converter as video data, a modulating circuit for modulating the video data stored in the memory into a modulated signal of an occupied frequency band corresponding to a transmission band of the signal line, a circuit for transmitting the modulated output of the modulating circuit to the signal line, a circuit for generating a synchronizing pulse and a frequency-dividing circuit for frequency-dividing the color subcarrier signal to provide signals necessary for the A/D converter, the memory, and the modulating circuit, wherein the video data is a signal which results from thinning the picked-up output at a predetermined ratio. |
