To enable a driver to drive safely with his attention concentrated on a front view by providing a first display source on-off control means for switching off input to a display source during the output of an ABS control signal.

In order to take in a control signal, a first display source on-off control means 12 is connected to a line to which a control signal of an ABS ECU 10 is outputted, and an on-off control circuit for switching off input to a display (display source) 18 when the cotnrol signal is actually sent is connected to the first display source on-off control means 12. In case of the display 18 being on, the first display source on-off control means 12 outputs a power supply off signal to the on-off control circuit 13 so as to switch off input to the display 18. At the time of emergency when ABS is in operation, a display image in an HUD device is effaced, and a driver can drive safely with his attention concentrated on a front view.