| 摘要 |
PURPOSE:To easily discriminate whether a sub-picture is in a state of a dynamic picture or a static picture, by varying a circumferential bordering color of the sub-picture depending on the time when the sub-picture has been switched to the dynamic picture or the static picture. CONSTITUTION:When a static picture signal is in an H level, a control signal of switches 9-11 is a sub-picture bordering signal (e) obtained by synthesizing a sub-picture content display signal (c) and a horizontal sub-picture display signal (d) by a NAND gate 17. Accordingly, to a D/A converter 13, a signal read out from memories 3-5 is applied when the signal (c) is in an H level, and supply voltage is supplied when the signal (e) is in an H level, and a sub-picture which has surrounded the contets of the sub-picture by white bordering is reflected on a cathode ray tube 20. On the other hand, when the static picture signal is in an L level, since control signal of the switches 9, 11 is in an L level, the bordering of the sub-picture is changed to green from white. Subsequently, a memory controlling circuit 16 inhibits write to the memories 3-5, and contents of the memories 3-5 are read out repeatedly, therefore, the sub-picture is reflected as a static picture. |
