383. Basic operations3-3-8. Masking the key signalsThese steps are taken to mask the key signals using the mask signal of the box pattern.1 Press the [FUNC] button to light its indicator, and press the [KEY] button to display the KEY menu.2 Turn [F1] to display the Mask sub menu.Mask Mask Invert6/9 Off OffManual4:3On3 Turn [F], and select the masking method using the Mask item.Off: The key signals are not masked.Manual: The area that is set using the MaskAdj sub menu is masked.4:3: The signals are masked to the 4:3 aspect ratio.4 Turn [F3] to set whether to invert the mask signal using the Invert item.On: The mask signal is inverted.Off: The mask signal is not inverted.5 Turn [F1] to display the MaskAdj sub menu.MaskAdj Left Top Bottom Right7/9 −25.00 +25.00 −25.00 +25.006 Turn [F] to [F] to set the area to be masked.Operation Parameter Description of setting Setting range Initial valueF Left Key left position −0.00 to +0.00 −.00F3 Top Key top position −0.00 to +0.00 +.00F4 Bottom Key bottom position −0.00 to +0.00 −.00F Right Key right position −0.00 to +0.00 +.00The Left setting cannot exceed the Right setting (and vice versa) and, similarly, the Top setting cannotexceed the Bottom setting (and vice versa). (figure shows the default values)0+50-50+500-50TOP (+25)BOTTOM (-25)(+25)RIGHT(-25)LEFTArea maskedArea where the key signal iseffectiveVideo signal range