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Kim & Chang Successfully Defends Patent Invalidation Action Regarding Vehicular Lamp Patent


Kim & Chang's Intellectual Property Practice recently defended a Dutch global lighting equipment manufacturer in a nullity action asserted against its patent by a local lighting equipment manufacturer in Korea.  By successfully showing that the technical idea of the subject patent resided in reducing heat transfer within vehicular lamps by forming protrusions between metal and plastic elements, and that this technical idea was not previously recognized in the prior art, Kim & Chang persuaded the three-judge Patent Court panel to recognize the inventiveness of the subject patent, overturning the negative first instance ruling that had been issued by the Intellectual Property Trial and Appeal Board (the “IPTAB”).

Vehicular headlamps, while small in size, play an important role in ensuring visibility for the driver and notifying other vehicles or pedestrians of the vehicle's presence.  With the commercialization of small LED headlamps in the 2000s, the thermal stability of lamps has emerged as an important technical challenge.  The inventor of the subject patent developed a technology to create a space between the metal and plastic parts of the lamp by adding small protrusions to the lamp, allowing the heat of the LED light source to bypass the plastic parts and be discharged to the outside.  This technology has been patented in numerous countries, including the United States, Japan and China, and this novel idea has significantly reduced manufacturing costs by allowing companies to use lower-grade plastic which are up to 4 times cheaper than heat-resistant plastics that must be used in conventional vehicular lamps.

Yet, after the nullity action was filed, the IPTAB ruled that the subject patent was invalid based on a prior art document that appeared to illustrate a vehicular lamp with a barb forming a space between metal parts and plastic parts, by determining that it would have been evident that such a space would have a heat transfer reduction effect.

On appeal to the Patent Court, our team thoroughly analyzed the prior art document at issue as well as researching in depth the field of vehicular lamps, and persuasively demonstrated that the technical idea of forming a space between metal and plastic parts to reduce their contact area and heat transfer actually was not known in the art prior to the subject patent.  Further, we successfully showed that the prior art “barb” that had been cited by the IPTAB was merely a means for fastening two disparate parts, and that its relative location, operating principle, and effects were different from the protrusions of the subject patent, resulting in the Patent Court overturning the IPTAB’s ruling.  As the local company did not appeal, the Patent Court decision was final and conclusive, and our client’s valuable technology was successfully protected.