Microthin.com, Inc. v. SiliconeZone USA, LLC, No. 06 C 1522, Slip Op. (N.D. Ill. May 6, 2009) (Kendall, J.).

Judge Kendall construed the claims of plaintiff Microthin’s patents to non-slip mats and based on the constructions granted defendant SiliconeZone summary judgment of invalidity as to the first claim of each patent. Of particular interest, the Court construed the following terms:

  • Non-Slip meant reducing or preventing smooth sliding motion, but the Court declined to add Microthin’s proposed requirement that it not be sticky to the touch because there was an independent claim that only added the requirement that the non-slip surface was not sticky to touch.
  • Consisting of was construed as a closed transitional phrase, as it is normally used in patent law.

Based on its construction of non-slip, the Court held the first claims of each patent invalid. Microthin’s sole argument against the asserted prior art was that it did not teach a non-slip surface because the surface was sticky to the touch. Because the Court construed non-slip without the sticky limitation, the first claims of each patent were invalid.