Monday, 3 May 2010

T 512/07 – Deadly Decibels

The applicant filed an appeal against the decision of the examining division (ED) refusing a European patent application because the invention was not disclosed in a manner sufficiently clear and complete for it to be carried out by a skilled person (A 83 in combination with R 27(1)(e) EPC 1973).

[3] During the appeal proceedings, the appellant has extensively amended the application documents. Objections under A 83 may under some circumstances be overcome by amending the claims, since thereby the “invention” referred to in A 83 may be so changed that it no longer depends on the insufficiently disclosed aspects of the application for its realisation. However such objections cannot be overcome by amendment of the description and drawings, since the amendment would then add subject-matter to the application as filed. In general, the presently claimed subject-matter has to be examined for compliance with A 83 on the basis of the application documents as originally filed.

In the present case the objection raised by the examining division concerned the disclosure of how to determine the powers of the ACK and NACK signals. This determination remains essential to carrying out the invention as defined in the independent claim of each of the present main and auxiliary requests.

Fig. 1 of the application

[4] The appellant essentially argued that in original figures 1 and 2 the y-axis pointing upwardly from 0(DTX) showed the power level on a linear scale for the transmission power to be used for ACK signals. Similarly, the y-axis pointing downwardly from 0(DTX) showed the increasing power level on a linear scale for the transmission power to be used for NACK signals. The transmission power of the ACK and NACK signals was of opposite polarity. In the introductory portion of the specification it was explained with regard to figure 1 that the background art receiver utilized one bit to transmit the response signals […]. In general the term “one bit signal” […] was used to refer to the digital signal which could have the logical value “0” or “1”. Thus, ACK could be represented as “1” (or “0”) and NACK could be presented as “0” (or “1”). Further, the first paragraph on page 3 indicated that the ACK/NACK signals were transmitted as “+1” or “-1”, referring to the analogue form. In contrast, the first paragraph on page 16 of the description as filed was argued to be related with the logical or digital value of the acknowledgment bit that did not refer to the analogue or physical form […].

[5] However, the board finds these arguments neither clear nor convincing and agrees with the reasoning of the appealed decision that the application considered as a whole does not describe in detail at least one way of carrying out the invention claimed, as required by R 27(1)(e), and does not disclose the invention sufficiently clearly and completely for it to be carried out by a skilled person, as required by A 83. In particular, the teaching of figures 1 and 2 as originally filed, even if interpreted in the light of the corresponding parts of the description […], does not allow a skilled person to carry out the invention, for the following reasons.

[5.1] The y-axis of original figures 1 and 2 shows the power level in a logarithmic decibel (dB) scale […] according to which a power level P=0 equals minus infinity. According to the original description […] the actual DTXsignal (Discontinuous Transmission, i.e. no response) occurrence is “to occur at 0 power level”. On a logarithmic scale, the reference “0(DTX)” would therefore have to be indicated at minus infinity on the y-axis. This, however, is not the case. “0(DTX)” is shown somewhere in the middle of the y-axis, which rather leads the skilled reader to the interpretation that DTX denotes a transmission signal of zero power on a linear scale. This, however, causes the problem that the power level for a NACK-signal, which according to original figures 1 and 2 is lower than the DTX level, would have to be negative, which is not technically possible since power is always greater than or equal to zero.

There is no indication in the application documents as filed that the power levels for ACK signals and for NACK signals shown in figures 1 and 2 are mirrored at 0(DTX) forming a lower and an upper graph with a common x-axis as argued by the appellant. The skilled reader would at least expect a hint in the description or in the drawings for such an unusual interpretation which, however, is not found. The board agrees with the argument presented in […] the appealed decision that the decision regions for ACK and NACK signals, indicated on the right hand side of the graph, suggest that there is only one graph and only one decision region threshold applying to all (logarithmic) power levels from minus infinity to plus infinity. […]

[6] The appellant pointed to the corresponding granted US patent. As the appellant conceded the grant of a patent in the USA is not binding for the EPO granting procedure. In addition, the parallel US patent specification is not identical to the European application, in particular figures 1 and 2 are different with regard to the logarithmic scale, so that the US patent is based on a different disclosure.

Fig. 1 of the U.S. application

The requirements of A 83 are not fulfilled if the invention disclosed in the European Patent application can only be carried out with the knowledge of a family member. Thus, the appellant’s argument […] does not convince. […]

[10] In the light of the above identified problems with the disclosure of the invention the board concludes that the requirements of A 83 and of R 27(1)(e) are not fulfilled for the main request.

To read the whole decision, click here.