| 摘要 |
PURPOSE:To obtain highly reliable display picture free from error operation by generating a video signal for a checking picture synchronously with a picture signal for a picture to be checked and comparing the video signal with a display picture signal. CONSTITUTION:Picture information to be displayed on respective cathode-ray tube (CRT) display dvices 7-11 through an interface bus 13 from a central processing unit 1 are inputted to display controlling devices 2-6. The display controlling devices 2-6 convert these picture information into video signals to display the signals on the CRT display devices 7-11. The video signals outputted to the CRT display devices 7-11 are inputted to a checking display controlling device 15 and a checking picture signal and a hard copying picture signal are also inputted to the checking display controlling device 15 through the interface bus 13. The checking picture signal and display picture signal are compared by a picture signal comparison controlling circuit. Display pictures are checked by updating the CRT display devices 7-11 cyclically. |
