We claim the ornamental design for a display case, as shown and described.
FIG. 1 is a perspective, exploded view of a display case, showing our new design;
FIG. 2 is a top, assembled perspective view of the display case of FIG. 1;
FIG. 3 is a bottom perspective view of FIG. 2;
FIG. 4 is a left side elevational view of FIG. 2;
FIG. 5 is a right side elevational view of FIG. 2;
FIG. 6 is a front elevational view of FIG. 2;
FIG. 7 is a rear elevational view of FIG. 2;
FIG. 8 is a top plan view of FIG. 2; and,
FIG. 9 is a bottom plan view of FIG. 2.
The circular shade line in FIGS. 1, 2, 3, and 8 are meant to denote the flatness of the top of the display case and form no part of the claimed design.