The ornamental design for an x-ray imaging device, as shown and described.
FIG. 1 is a top plan view of an x-ray imaging device showing my new design;
FIG. 2 is a bottom plan view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear side elevation view thereof;
FIG. 5 is a left side elevation view thereof, the right side being a mirror image;
FIG. 6 is a front perspective view thereof in an alternative configuration; and,
FIG. 7 is a rear perspective view thereof in another alternative configuration.
The broken lines immediately adjacent the claimed areas in FIG. 2 represent the bounds of the claim, and all other broken lines in the drawing views represent environmental structures. None of the broken lines form a part of the claimed design.