1. At what point in time could Pfaff have applied for a patent on his invention?

2. What rule does the Supreme Court set forth for determining when the on-sale bar applies?

3. What could Pfaff have done differently in order to avoid this outcome?

OPINION: JUSTICE STEVENS delivered the opinion of the Court.

Section 102(b) of the Patent Act of 1952 provides that no person is entitled to patent an “invention” that has been “on sale” more than one year before filing a patent application. We granted certiorari to determine whether the commercial marketing of a newly invented product may mark the beginning of the 10-year period even though the invention has not yet been reduced to practice.