Adjustable pencil sharpener

A pencil sharpener comprising:

• a waste case having
• a mounting hole defined in the waste case and having an inner wall;
• and
• multiple positioning segments formed on the inner wall of the mounting hole;
• a blade base mounted in the waste case and having a bottom;
• a blocking chunk moveably mounted on the bottom of the blade base along an axial direction of the blade base and having a bottom;
• a blade mounted securely on the blade base;
• a rotating knob mounted rotatably in the mounting hole of the waste case and having at least one engaging segment, wherein each one of the at least one engaging segment selectively engaging one of the positioning segments of the waste case;
• and
• an adjusting shaft connected securely with the rotating knob and disposed on the bottom of the blocking chunk, wherein when the rotating knob is rotated, the adjusting shaft is rotated to push the blocking chunk to move along the axial direction of the blade base.