Saturday, 1 January 2011

T 1741/07 – He Knows It All

The present decision deals with the decision of the Examining Division to refuse a patent application for lack of inventive step over a combination of documents D1 and D2.

Claim 1 of the main request read:

A railway monitoring system (100), comprising:
an optical fiber (101) having a plurality of parts spaced apart along the length of the optical fiber, each part of the plurality being attachable to a respective portion of one of a pair of rails (103,105) of a track,
an optical signal emitter (107) connected to the optical fiber (101) for emitting an optical signal into the optical fiber, and
an optical signal analyzer (111) connected to the fiber for receiving and analyzing altered optical signals;
characterised in that the plurality of parts comprises a first plurality of Bragg gratings (S), each Bragg grating (S) having a distinct reflected wavelength which is altered upon a change in strain arising from a respective portion of the rail, and said optical signal analyzer (111) receives altered optical signals in the form of reflected signals and is adapted to detect shifts in the reflected wavelengths of the Bragg gratings, a shift being indicative of a change in strain at a respective portion of the rail.

The appellant argued, inter alia, that the relevant skilled person, a railway engineer with experience in the field of network monitoring systems, was of a very conservative nature, and would not have considered introducing new unproven technologies.

[2.1] The document D1, like the present application, to railway monitoring systems based on optical sensors, and is the only available prior art document relating to such systems. Thus it is considered to represent the best starting point for the assessment of inventive step.

[2.1.1] It is noted that the appellant has argued extensively, in particular with reference to the two “witness statements” […], that the person skilled in the art is a railway engineer with experience in the field of network monitoring systems, and that such persons are of a very conservative nature, and would thus not consider it obvious to introduce new unproven technologies (contrasted to the conventional systems using electro-magnetic sensors).

In the present case, the implication of this argument is that the skilled person would not consider replacement of the conventional system using electro-magnetic sensors with a system based on optical fibres, since these have not previously been used in the railway network, and would thus not consider D1.

[2.1.2] This argument appears to the board to be based on the assumption that the skilled person is starting from a situation in which only electro-magnetic sensors were known. However, it is part of the established case law of the boards of appeal that the skilled person is aware of all of the prior art in the relevant technical field.

Thus, in the present case he would be aware of the teaching of D1, and for the reason indicated in paragraph [2.1] above, the skilled person would adopt this document as his starting point and hence assume the use of optical fibres in a railway monitoring system.

Unsurprisingly, the request was rejected for lack of inventive step.

Should you wish to download the whole decision, just click here.

To have a look at the file wrapper, click here.

NB: This decision has already been reported on Kluwer Patent Blog.