| 摘要 |
PURPOSE:To display a picture excellent in visibility and decoration characteristic by constantly supplying a secondary picture signal to a display means by a change over circuit during the erase of a main picture to display a time or the like by using all the screen after the main picture is erased. CONSTITUTION:During the erase of the main picture, the signal A for erasing the main picture is supplied to a character and graphic generating circuit 1, thereby, the circuit 1 generates R', G', B' character and graphic signals for displaying the secondary picture such as the time on all the screen of a CRT 5. The erasing signal A of the main picture of L level is also supplied to a NAND gate 10. In this case, irrespective of the output of a NOR gate 9 supplied to the NAND gate 10, the NAND gate 10 supplies a change over signal of H level to the change over terminal S of the video/data change over circuit 3. Accordingly, the circuit 3 constantly selects the R', G', B' character and graphic signals and supplies to the CRT 5, so that, the secondary picture such as an analog clock can be displayed on all the screen.
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