Mere characterization of the prior art that does not form the basis of an argued distinction does not rise to the level of prosecution history disclaimer. Here, for example, the patentee’s characterization of the prior art as including only a single perforation line on its containers but instead distinguishing the prior art from the claimed invention on the basis of a missing bridge connector was found to be insufficient to disclaim single perforation designs from the scope of the claimed invention. Nevertheless, it may be best to avoid unnecessary characterizations of the prior art that do not form the basis of an argued distinction.
Background / Facts: The patents being asserted here are directed to plastic food containers having tamper-evident and tamper-resistant features. The claims recite containers having a hinged plastic bridge between the top and bottom portions of the container, with the bridge having a “frangible section” (e.g., a score line or perforation) that must be severed in order to open the container. In response to a rejection during examination, the patentee described the prior art’s frangible section as “a perforated line, a groove or the like around the receptacle 210 in the outer segment 222.”
Issue(s): Whether this characterization of the prior art as including only a single perforation disclaims single perforation designs from the scope of the claimed invention.
Holding(s): No. “[The patentee’s] description of [the prior art] as containing a ‘perforated line, a groove or the like,’ was not the basis of [the argued] distinction. To the contrary, [the patentee] distinguished its invention from [the prior art] on the basis that ‘[n]owhere in [the prior art] is there any disclosure, teaching or suggestion to modify the container therein to provide a tamper evident bridge that connects a cover portion to a base portion.’ … The distinction between [the prior art] and the [claimed] device has no relation to the number of score lines on a tear strip, but rather to differences in the structure and opening mechanism as a whole.”