| 摘要 |
PURPOSE:To finely set the interval of receiving focus regions to a display visual field even in a case displaying a shallow region by mounting a means for finely controlling the interval of a plurality of the receiving focus regions as the setting of the depth of a visual field becomes shallow. CONSTITUTION:When the depth of a visual field is set shallowly from an operation panel, the memory regions of the corresponding receiving delay time control data in memory circuits 14A, 14B are indicated from a receiving delay time control circuit 16 on the basis of addresses DA, DB and receiving delay time control data are selected on the basis of addresses FSA, FSB in order to set a desired receiving focus region. By this method, a desired delay time is determined and a plurality of receiving focus regions are set so that the interval thereof becomes fine. The number of the receiving focus regions within the depth of a visual field is set in the same way as a deeply set case. Therefore, the image qualities of sector images S1, S2 can be enhanced because the receiving focus regions are set at the same pitch within the depth of a visual field. |
