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American Science & Engineering Inc. v Rapiscan Systems Limited, UK, High Court (Patents Court), Arnold J, 11 April 2016

ASE’s patent related to a covert mobile X-ray scanning system. By the time the case came to trial Rapiscan had admitted that their rival scanning system would infringe if the patent was valid but contended that the patent lacked inventive step over an earlier disclosure (Swift).

Two key features were found to be missing from the Swift disclosure. The detector module in Swift was not entirely contained within the body of an enclosed conveyance as the closet doors containing the detector in Swift were required to be opened and secured when the detector was in use. In addition Swift also lacked a relative motion sensor for generating a relative motion signal based on relative motion between the enclosed conveyance and an inspected object.

The judge considered that the inventive concept of the patent was the combination of (i) a vehicle containing a flying spot X-ray source and a backscatter detector, (ii) the source and the detector being entirely enclosed within the body of the vehicle when the vehicle is in motion during the course of an inspection and (iii) a relative motion sensor generating a signal based on the relative motion of the vehicle and the inspected object (thus enabling the aspect ratio of the image to be corrected).

This enabled a mobile X-ray scanner to be used for covert imaging in three modes: (i) with the vehicle moving past the target (“drive-by” mode), (ii) with the vehicle stationary as the target moves past it (stationary or “drive-past” mode) and (iii) with the vehicle overtaking the target while they are both in motion.

Although the individual steps to adapt the Swift disclosure to arrive at the claimed invention might have been individually obvious, the judge considered that in order to arrive at the combination, the skilled person would have to conceive of making a mobile, covert, backscatter-only system which could operate in drive-past mode and incorporated a relative motion sensor for that purpose, despite the fact that Swift contains no hint of either covert or drive-past operation and indeed teaches away from both. It was only with hindsight that it could be seen that the necessary changes were relatively simple ones and hence the patent was upheld as valid.

A copy of the judgement can be found here.

Headnote: Nicholas Fox, Simmons & Simmons