We claim the ornamental design for a pencil sharpener, as shown and described.
FIG. 1 is a perspective view of a pencil sharpener according to our new design;
FIG. 2 is a second perspective view of the pencil sharpener of FIG. 1;
FIG. 3 is a front elevational view of the pencil sharpener of FIG. 1;
FIG. 4 is a rear elevational view of the pencil sharpener of FIG. 1;
FIG. 5 is a right side elevational view of the pencil sharpener of FIG. 1; and,
FIG. 6 is a left side elevational view of the pencil sharpener of FIG. 1.
The broken lines showing features on the front and rear in FIGS. 1–4 are included for the purpose of illustrating environment and form no part of the claimed design.