Is the Examining Division always correct when interpreting prior art?

Background

In the decision under appeal, the decision of the ED to refuse application no. EP14744010.1 was appealed by the A. The key issue at hand was that the ED refused the application on grounds that the subject-matter of claims 1, 8 and 9 of the sole request lacked inventive step over the disclosure of document D1 in combination with document D2 and the common general knowledge of the person skilled in the art. 

The Appeal

The decision of the ED to refuse the EP14744010.1 was appealed by the A. With its statement of grounds of appeal, the A provided arguments against the ED’s finding of lack of inventive step. The A requested that the decision under appeal be set aside and that a patent be granted on the basis of the documents on file at the time of filing of the statement of grounds of appeal. As an auxiliary measure, the A also requested oral proceedings.

The A received a notice of the summons to oral proceedings, wherein the Board gave the preliminary opinion that it tended to agree with the A that the ED’s conclusion of lack of inventive step in light of D1 in combination with D2 and the common general knowledge of the skilled person was incorrect. The Board therefore signalized that it was inclined to remit the case to the department of first instance for further prosecution, should the applicant agree to withdraw the request for oral proceedings. The A agreed.

Inventive Step

In brief, claim 1 concerned a network device comprising a receiver configured to receive a transport stream of a sequence of packets via which a video data stream was transported, wherein, among other features, it was specified that the video data stream had tiles of pictures of the video encoded thereinto along a coding order in units of slices, wherein each slice started with a slice header. It was also specified that the network device of claim 1 further comprised an error handler configured to identify lost packets in the sequence of packets by identifying the slice headers of a first not lost packet in the sequence of packets in the event one or more packets would get lost from the sequence of packets in the transport stream.

The inventive step assessment in the decision under appeal hinged on document D1, which disclosed signalling a slice address of a reference slice in a header of a dependent slice so that a loss of the reference slice could be detected thanks to a presence of a syntax element "ref_slice_address" specifying the address of the reference slice on which the “current slice” was dependent on. The ED considered that the syntax element "ref_slice_address" in the header of a dependent slice pointed to the independent slice that contained the dependent slice, whereas A was of the opinion that the syntax element "ref_slice_address" in a dependent slice segment (dependent slice) referred to the slice address of the immediate predecessor slice segment rather than to the slice address of the independent slice segment (independent slice) to which a current slice segment belonged. The A hence argued that the ED had erroneously interpreted D1, based on a difference of interpretation of the disclosure of D1. During the appeal, the Board sided with the interpretation presented by the A, concluding that since D1 did not disclose a signalling method with a syntax element in the header of a dependent slice pointing to an independent slice that contained the dependent slice, the person skilled in the art adapting the method known from document D1 would not have arrived at the claimed signal syntax.

Hence, the Board held that the ED based its inventive step assessment on its erroneous interpretation of D1, which led to the ED’s erroneous conclusion that the subject-matter of claim 1 lacked inventive step. 

Decision of the Board of Appeal

The Board decided that the ED’s erroneous interpretation of document D1 not only called into question the relevance of the document for assessing patentability but also the completeness of the search conducted for the invention. Thus, the Board concluded that if it were itself to decide on the substance of the case, it would have to carry out a full examination of the application with regard to patentability requirements. The Board considered that the misinterpretation of D1 could have brought the search to a premature end, which could mean that an additional search was necessary. As a consequence, the Board found it justified to remit the case to the department of first instance for further prosecution.