Periphery monitoring device

1. A periphery monitoring device, comprising:

at least one processor configured to implement:

a coupling determiner that determines whether a towed vehicle is coupled to a towing vehicle to which the towed vehicle can be coupled;

a target setter that sets a target moving position to be a target for moving at least the towed vehicle coupled to the towing vehicle;

a storing controller that stores, as a moving target image, an image, including the target moving position, of a peripheral image captured by an image capture device at a first time and provided at the towing vehicle;

an image controller that displays the stored moving target image in association with the towing vehicle or the towed vehicle included in a current image capture by the image capture device at a second time after the first time and currently displayed on a display device; and

a blind-spot determiner that determines whether the target moving position enters a dead area caused by the towed vehicle in an imaging area of the image capture device, wherein

the image controller displays the stored moving target image in association with the towing vehicle or the towed vehicle when the target moving position is to enter the dead area.

2. The periphery monitoring device according to claim 1 , wherein

the storing controller stores at least the moving target image generated when the target moving position is set.

3. The periphery monitoring device according to claim 1 , wherein

the storing controller starts storing the moving target image when the target moving position is set.

4. The periphery monitoring device according to claim 1 , wherein

when the target moving position is in the dead area on the current image, the image controller superimposes at least an image of the target moving position included in the stored moving target image, on at least an area of the dead area, the area corresponding to the target moving position.

5. The periphery monitoring device according to claim 4 , wherein

the image controller superimposes the moving target image on the dead area in a transparent mode.

6. The periphery monitoring device according to claim 1 , wherein

when a first moving target image and a second moving target image exhibit a difference in content equal to or greater than a given value, the image controller displays the second moving target image in association with the current image, the first moving target image being stored when the target moving position is set, the second moving target image being stored immediately before the target moving position enters the dead area.

7. The periphery monitoring device according to claim 1 , further comprising:

a position acquirer that acquires a current position of the towing vehicle with reference to a position of the towing vehicle at the time of setting the target moving position;

an angle acquirer that acquires a coupling angle between the towing vehicle and the towed vehicle; and

an index acquirer that acquires a trailer index corresponding to a size of the towed vehicle, the trailer index being superimposable on the current image, wherein

in displaying the stored moving target image in association with the current image, the image controller determines a display posture of the trailer index in accordance with the current position of the towing vehicle and the coupling angle, and displays the trailer index on the current image in a superimposed manner.