| 摘要 |
<p>1535410 Television receivers SABA SCHWARZWAELDER APPARATE-BAUANSTALT AUGUST SCHWER SOEHNE GmbH 7 Oct 1976 [2 April 1976 18 June 1976] 41658/76 Heading H4F A television receiver is arranged to display a main picture from one transmitted programme, a part of the picture from another programme being displayed in a blanked portion of the main picture. The receiver includes two tuners 3, 5, two i.f. stages 4, 9, and two horizontal and vertical sync. separation stages 7, 13. The main picture signal passes via tuner 3 and a changeover stage 12 to the display tube 8. A comparator 14 responsive to the sync. signals controls the changeover stage. It causes the second picture signal, from tuner 5, to pass to the tube 8 so that a partial picture appears in that quadrant (II) of the display that would contain no horizontal (H2) or vertical (V2) sync. band were the whole of the second picture signal to be superimposed on the main picture signal (Fig. 4, not shown).</p> |
