FIG. 1 is a front view of a pen case showing my new design;
FIG. 2 is a rear view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a plan view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a front view which is in the unfolded state of a pen case of FIG. 1;
FIG. 8 is a rear view of a pen case of FIG. 7;
FIG. 9 is a left view of a pen case of FIG. 7;
FIG. 10 is a right view of a pen case of FIG. 7;
FIG. 11 is a plan view of a pen case of FIG. 7; and,
FIG. 12 is a bottom view of a pen case of FIG. 7.
The broken lines shown are included for the purpose of illustrating the unclaimed portions of and form no part of the claimed design.