The ornamental design for a displaydevicestand, as shown and described.
FIG. 1 is a front perspective view of a display device stand, showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left-side view thereof;
FIG. 5 is a right-side view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is a rear perspective view thereof, in which a display device in broken lines is provided to illustrate an example environment; and,
FIG. 9 is a partially-exploded rear perspective view of FIG. 8, in which the unclaimed display device is shown separated from the claimed design.
The broken lines are for illustrative purposes only and form no part of the claimed design. The shade lines in the figures show contour and not surface ornamentation.