| 摘要 |
PURPOSE: To improve the quality of an image by spatially filtering a generating signal and removing frequency components of less importance to recognized image quality, and transmitting the rest by using double side-band orthogonal phase modulation by Nyquist bandwidth. CONSTITUTION: A multiplexer 18 multiplexes 9 components to a storage device 22 together with digital audio information and data. The stored information is read out by a control circuit 20 as two streams corresponding to odd- and even-numbered scanning lines and converted by D/A converters 24 and 26 into analog signals. Then 3-MHz low-pass filters 28 and 30 filter the two data streams and an orthogonal phase modulator 32 imposes orthogonal phase modulation on two composite 3-MHz signals over a carrier signal 34 having 6-MHz bandwidth. After 11 blocks of respective 9 lines, one block of digital audio information and other data is transmitted. Consequently, the quality of the image is improved. |
