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May 24, 2010

Patent Slips on Non-Slip Surface

Microthin.com sued SiliconeZone computer mouse pad patents 5,942,311 & 5,997,995, which claim "a thin, non-slip mat or pad made of plastic" and a method of making the same, respectively.  After claim construction, the district court, by summary judgment, found the asserted claims, claim 1 of each patent, anticipated by 5,738,325. Microthin.com appealed construction of the claim term "non-slip," wanting the term to include "not sticky."

Microthin.com v. SiliconeZone (CAFC 2010-1079) nonprecedential

The district court construed "non-slip" to mean "reduces or prevents smooth sliding motion." Opinion at 7, 12. Microthin challenges the district court's interpretation, arguing that "non-slip" means "to reduce or prevent smooth sliding motion without being sticky to the touch." To support its proposed construction, Microthin points to two places in the specifications where the patents discuss a non-slip surface that is not sticky to the touch. See '311 patent col.1 ll.6-10, col.3 ll.3-5; '995 patent col.1 ll.7-11, col.3 ll.7-11.

We agree with the district court that the plain and ordinary meaning of "non-slip" is "reduces or prevents smooth sliding motion" and does not distinguish between sticky and non-sticky characteristics. Claim 1 in each patent does not include any limitation suggesting that the non-slip surface must not be sticky to the touch. Moreover, dependent claim 8 of the '311 patent adds a single limitation to claim 1, "wherein the non-slip surface is not sticky to the touch." '311 patent col.6 ll.4-5 (emphasis added). "[T]he presence of a dependent claim that adds a particular limitation gives rise to a presumption that the limitation in question is not present in the independent claim." Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed. Cir. 2005) (en banc). In cases such as this, "where the limitation that is sought to be 'read into' an independent claim already appears in a dependent claim, the doctrine of claim differentiation is at its strongest." Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 910 (Fed. Cir. 2004). Hence, the claim language fully supports the district court's construction.

Microthin also cites the specification as indicating that the non-slip surface is not sticky. These statements do not, however, justify interpreting the term non-slip different from its plain and ordinary meaning. The patentee did not, in this case, act as his own lexicographer defining "non-slip" contrary to its plain and ordinary meaning. To be his own lexicographer, a patentee must use a "special definition of the term [that] is clearly stated in the patent specification or file history." Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1580 (Fed. Cir. 1996); see also CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366 ("[T]he claim term will not receive its ordinary meaning if the patentee acted as his own lexicographer and clearly set forth a definition of the disputed claim term in either the specification or prosecution history."). Here, the specification contains no such clear definition of "non-slip."

Likewise, the specification and prosecution history do not present a clear disclaimer such as the patents in SciMed Life Systems, Inc. v. Advanced Cardiovascular Systems, 242 F.3d 1337 (Fed. Cir. 2001). We have stated that "claim terms take on their ordinary and accustomed meanings unless the patentee demonstrated an intent to deviate from the ordinary and accustomed meaning of a claim term by redefining the term or by characterizing the invention in the intrinsic record using words or expressions of manifest exclusion or restriction, representing a clear disavowal of claim scope." Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1327 (Fed. Cir. 2002).

Nowhere in the specification does it suggest that a non-sticky surface is "an essential component of the invention," nor does it clearly disclaim the use of a sticky surface. See Liebel-Flarsheim, 358 F.3d at 908. We conclude that the district court correctly construed the non-slip limitation by giving it the plain and ordinary meaning.

Although anticipation is a question of fact, it may be decided on summary judgment if there is no genuine dispute of material fact. Leggett & Platt, Inc. v. VUTEk, Inc., 537 F.3d 1349, 1352 (Fed. Cir. 2008). Because Microthin's appeal of anticipation hinged entirely on our adoption of its claim construction of non-slip, we affirm the district court's grant of summary judgment; claim 1 of each patent is invalid.


Posted by Patent Hawk at May 24, 2010 3:57 PM | Claim Construction


If 'not sticky' was an important limitation why didn't they assert dependent claim 8 in the suit?

Posted by: anon at May 24, 2010 7:54 PM

"without being sticky" ?? How do you interpret non-slip to include a lack of some other unrelated factor? Why can't I put a bunch of glue on the ground and call it a "non-slip" surface?

Posted by: Patent Attorney PA NY NJ at May 25, 2010 6:11 AM