| 摘要 |
PROBLEM TO BE SOLVED: To provide a picture compositing device capable of reducing system cost without needing a dual type memory. SOLUTION: Main and sub-picture signals S1, S2 are respectively thinned by thinning parts 1, 2. These thinned main and sub-picture signals are properly distributed to line buffers A, B and C, D by respective demultiplexers 4, 5. These distributed picture signals are properly selected by respective multiplexers 6, 7 and sent to a selector 8 and a single port type DRAM 10. A picture signal from the multiplexer 6 and a picture signal P10 read out from the DRAM 10 are selected by the selector 8 and outputted as a composite picture signal S3 for displaying both the picture signals in parallel. Since the device is provided with the line buffers C, D, the demultiplexer 5 and the multiplexer 6, writing and reading in/from the DRAM 10 can be executed without being mutually interfered. |
