| 摘要 |
PURPOSE:To describe always a mark in a direction based on the vertical direction independently of deflection by subjecting a display position to coordinate conversion in accordance with the deflection quantity of a ship itself and reading out the mark to display it in a determined display position. CONSTITUTION:The classification and position information of the mark are stored in an RAM 4 with an XY coordinate system for the convenience of succeeding processings, and contents of an ROM 5 are written in a prescribed address of a memory 6 on a basis of these information. At this time, the write position in the memory 6 of the mark which is designated by the RAM 4 is converted in accordance with a deflection quantity theta (angle) of the ship itself to the due north, and the processing for this conversion is performed by a coordinate converting circuit 7. The coordinate converting circuit 7 obtains theta<0>= tan<-1> (X/Y) on a basis of X and Y values from the RAM 4 and introduces the deflection quantity theta from a compass 9 of a gyro or the like to execute the conversion processing and determines an address of the memory 6. Addresses of the memory 6 correspond to picture elements of a display device 10, and stored contents of the memory 6 are displayed on the display device 10 as they are. |
