T 1351/04 (File search method/FUJITSU) 18-04-2007

1. Admissibility of the appeal

The appeal complies with the requirements referred to in Rule 65(1) EPC and is therefore admissible.

2. Amendments

The Board is satisfied that the amended claims are properly based on the original disclosure, so that Article 123(2) EPC is complied with.

Claim 2

3. The claimed subject-matter

The Board considers it useful first to deal with claim 2, which is dependent on claim 1 in the sense of Rule 29(4) EPC. It is directed to a computer-executable file search method comprising computer-executed steps. The method requires that the file to be searched be structured as records containing fields forming different hierarchical levels. First an index file is created. This file contains nodes in a tree structure which are used for searching for key character strings. At each node there is so-called management information, which includes information about the starting position and the number of corresponding records in the file to be searched. This information permits the desired records to be retrieved directly when the node having the desired key character string has been found (cf paragraph [0042] of the description). When only keys of high-level nodes are used it is thus not necessary to follow the tree structure all the way down to the leaf nodes in order to retrieve the desired record information.

4. Technicality

The claimed method requires the use of a computer. It has therefore technical character and constitutes an invention within the meaning of Article 52(1) EPC (cf T 258/03 - Auction method/HITACHI, OJ EPO 2004,575).

5. The prior art

The Board agrees with the appellants and the examining division that D1 is the closest prior art document. According to D1 (cf Table 1), the file to be searched ("primary file") is divided into records (r1 to r14). Each record comprises values for attributes Ai (p.19, first paragraph). Records that have the same key character string in a field at the same hierarchical level (cf Table 1, eg string "18" at level A1) are arranged in series (eg r1 to r7, the records corresponding to the condition A1 = "18"). An index file having a tree structure is generated. As shown in fig.1, horizontal pointers connect all the son nodes of a parent node. Vertical pointers are used to change levels in the tree. The leaf nodes (the bottom row of nodes in fig.1) contain references to the primary file. There is no indication that non-leaf nodes also contain such references.

6. Novelty

6.1 The examining division found the following differences between the invention and D1:

a) the method according to the invention is carried out on a more specific file structure; and

b) each node in the index includes the starting position information and number information used for retrieving records.

6.2 The Board is however not convinced that the allegedly distinguishing feature a) exists. As noted above, according to D1 a record (r) comprises values (Ai) allocated to each of a plurality of hierarchical levels. The location of these values may be termed fields (corresponding to the columns in Table 1). The file is constructed in such a way that records having the same key character string in a field at the same hierarchical level are arranged in series (cf Table 1). Moreover, for each record the first field is the top hierarchical level (A1), and subsequent fields (A2, A3) form lower hierarchical levels (cf fig.1). Hence, the file structure appears to be identical in the terms of the claim.

6.3 On the other hand, in D1 the non-leaf nodes are not said to contain references to the primary file. Thus, due to distinguishing feature b), or at least its implementation, the subject-matter of claim 2 is new (Article 54 EPC).

7. Inventive step

7.1 To assess the inventive step it must first be considered in how far the features of the claim, and in particular distinguishing feature b) (cf point 6.1), contribute to the solution of a technical problem.

7.2 According to the description of the present application, the invention relates to a method for "promptly searching for and extracting data from a file" (cf paragraph [0001]). The data searched for can be of any kind, eg of a commercial nature as in the described embodiment, and thus have no technical relevance in themselves. They are stored as records having certain "start positions", ie memory addresses in the file to be searched. The computer reads these addresses in the form of "management information" in the index file and retrieves the associated data from the file to be searched. The management information thus controls the computer by directing it to a certain memory location. Functional data, intended for controlling a technical device, are normally regarded as having technical character. One example of this is decision T 110/90 - Editable document form/IBM (OJ EPO 1994,557), in which "control items" (eg "carriage return") were regarded as having a technical effect due to their being capable of controlling hardware such as a printer. It therefore appears that the management information contained in the present claims should be regarded as contributing to the technical character of the search method. The technical effect is the control of the computer along the path leading to the desired data. The path itself, which is determined by the search strategy as reflected by the management information, has technical character for the same reason. Obviously the choice of path will determine the searching characteristics, such as the speed, something which can constitute an additional indication of technicality.

7.3 The above conclusion is also consistent with decision T 52/85 - Listing of semantically related linguistic expressions/IBM (not published in the OJ EPO). That case concerned a method for displaying a list of expressions semantically related to an input linguistic expression (cf point IV of the decision). The method comprised looking up addresses for accessing memories. These features were said to be conventional (point 5.3) but not nontechnical. The decision points out that "internally a computer functions technically" (point 5.8). Decision T 52/85 seems to suggest that as long as a claimed method for searching a data file is concerned with the way a computer performs the search, it may be technical. If however the kind of data is decisive, the method's contribution is nontechnical (cf T 52/85, point 5.2). As already noted, in the present case the kind of data searched for is of no importance.

7.4 It follows that all features of claim 2 that have a direct bearing on how the search is conducted should be considered for inventive step. This includes distinguishing feature b). Their effect is to speed up searches that involve only keys of high-level nodes. The technical problem when starting out from D1 can thus be seen as devising a search method that is particularly efficient for searching a data file using mainly keys of high-level nodes.

7.5 The examining division held that adding starting position information and number information to non-leaf nodes was obvious if the doubly-chained tree indexing scheme described in D1 were applied to the same file content as in the present application (cf the decision, p.2, last complete paragraph). However, as already noted (point 6.2), the file structure shown in D1 and the one according to the claim appear to be identical. Moreover, the examining division failed to indicate why the skilled person would make this change, ie what technical problem he expected it to solve. It is naturally always possible to allege that the skilled person would have foreseen any advantages an invention achieves, especially when the differences between the invention and the prior art are small, but in the absence of any hint in the prior art such an argument is indistinguishable from hindsight and thus inherently weak.

7.6 The Board has also considered the fact that the index according to the invention occupies more memory because of the extra record information stored. It could therefore be argued that the invention simply defines a new trade-off point at which searching speed is valued higher and memory cost lower than in the prior art. However, nothing proves that the skilled person was aware that such a trade-off existed since, again, in the prior art the record information is always located in the leaf nodes.

7.7 A final point is that D1 does not stress the importance of the structure of the primary file. Only the present application has demonstrated that this structure enables the direct access from a high-level (non-leaf) node to all the records associated with this node. This can be regarded as a non-obvious insight.

7.8 It follows that the subject-matter of claim 2 must be regarded as involving an inventive step over the available prior art (Article 56 EPC).

Claim 1

8. Claim 1, on which claim 2 is dependent, is directed to a computer-executable index file creation method. It also comprises distinguishing feature b) (cf point 6.1 above). However, it contains no searching steps but only steps of establishing an index to be used for searching a file. The question therefore arises whether the features of claim 1 contribute to a technical character in the same way as in claim 2.

9. Since the claimed method does not comprise the search, the computer does not read the management information. The claim is instead concerned with the automatic collection and storage of this information (cf the last feature of claim 1). The method results in the creation of an index file. This file is a technical means since it determines the way the computer searches information, held above (cf point 7.2) to be a technical task. The subject-matter of claim 1 can thus be regarded as a method of manufacturing a technical means. Normally, such a method has technical character. The Board is of the opinion that the present case is no exception since the claimed method, although involving only the recognition and storage of information, requires virtually no human intervention and is independent of the kind of information involved.

10. It follows that distinguishing feature b) in claim 1 contributes to a technical solution of a technical problem. For the reasons given in connection with claim 2, the method of claim 1 is new and involves an inventive step (Articles 54 and 56 EPC).

Claims 3 and 4

11. The index file creation device according to claim 3, realised by a computer program installed in hardware, is a physical entity comprising processing units which, by their nature, have technical character. Thus it is an invention within the meaning of Article 52(2) EPC. Furthermore, it is new and involves an inventive step for the reasons given above in connection with claims 1 and 2.

12. The same applies to claim 4, which is dependent on claim 3.

Claims 5 to 7

13. The computer program of claim 5 is defined in the same terms as method claim 1. When run, it controls the computer in a way which the Board holds to have technical character. This means that it produces a "further technical effect" in the sense of decision T 1173/97 - Computer program product/IBM (OJ EPO 1999, 609). Thus, it is not excluded from patentability under Article 52(2),(3) EPC. Furthermore, it is new and involves an inventive step for the reasons given above in connection with claims 1 and 2.

14. The same applies to claim 6, which is dependent on claim 5. The memory product of claim 7, which includes the features of claim 5 or 6, is also patentable.