T 0328/00 17-09-2002

1. Admissibility of appeal

The appeal is admissible.

2. Admissibility of opposition

The appellant objected for the first time in his statement of the grounds of appeal that the opposition had not been appropriately substantiated in the statement of grounds of opposition.

As already pointed out by the board in the annex to the summons to oral proceedings, during the opposition proceedings before the first instance the appellant apparently had no particular difficulty in understanding and countering the arguments put forward in the notice of opposition in support of an alleged lack of inventive step in view of the documents cited by the opponent (respondent), from which it can be concluded that the opposition was adequately substantiated, at least in respect of the alleged lack of inventive step. The appellant did not dispute this view during the subsequent oral proceedings, and the board concludes that the opposition is admissible in so far as at least one of the grounds of opposition invoked by the respondent under Article 100(a) EPC, namely that based on lack of inventive step (Articles 52(1) and 56 EPC), has been properly substantiated as required by Rule 55(c) EPC (see decisions T 182/89, OJ 1991, 391, point 3 of headnote II and T 204/91, not published in OJ, point 5 of the reasons, last paragraph).

3. Appellant's main request - Compliance of the amendments with the requirements of Articles 123(2) and (3) EPC

3.1. Claim 1 according to the main request differs from claim 1 as granted in that the expression "one or more drilling parameters" has been replaced by "at least two drilling parameters", and in that the expression "at least one of" preceding the recitation of the two particular drilling parameters considered in the claim has been deleted.

In the original application the dwell times are said to depend upon, and to be determined by "various drilling parameters" (column 6, lines 25 to 31 of the publication of the original application), wherein "one drilling parameter used is the size or diameter of the drill tool" (column 6, lines 35 to 37) and "another parameter [...] is the hole [placement] accuracy" (column 6, lines 46 to 51), the description further specifying "other possible parameters affecting the dwell time" (column 6, line 56 to column 7, line 6). In the board's view, these statements constitute a clear basis for the determination of the dwell time on the basis of two or, alternatively, on the basis of more than two of the drilling parameters, the parameters including the diameter of the drill tool and the degree of hole placement accuracy. The determination of the dwell time on the basis of just two parameters constituted by the diameter of the drill tool and the degree of hole placement accuracy is also supported by the embodiment disclosed in the original application with reference to the table shown in Figure 4 and involving the use of two such parameters (column 7, lines 22 to 26).

Accordingly, there is a clear basis in the original disclosure for the amendments made to claim 1 according to the main request.

3.2. Independent claim 3 of the main request differs from claim 3 as granted in that the expression "according to one or more predefined drilling parameters" has been replaced by "according to at least two predefined drilling parameters".

As already put forward in point 3.1 above, the determination of the dwell times according to at least two drilling parameters is directly and unambiguously derivable from the disclosure of the original application. The argument of the respondent that there is no basis in the original application for the limitation to at least two parameters without simultaneously restricting the parameters to the two particular drilling parameters specified in the amended claims 1 and 10 is not convincing because the original claim 3 and the passage in column 6, line 56 to column 7, line 6 of the original description already support the determination of the dwell times on the basis of a plurality of drilling parameters, without these parameters being necessarily restricted to the drill tool diameter and the placement accuracy of the drill hole.

3.3. Independent claim 10 of the main request differs from claim 10 as granted in that the dwell times also vary "in accordance with a desired degree of placement accuracy of a given hole to be drilled" and in that the selected dwell time also corresponds to "said desired degree of placement accuracy".

These amendments are also based on the passages of the original disclosure mentioned in point 3.1 above, and in particular on those passages referring to the determination of the dwell time according to the desired hole placement accuracy.

3.4. The additional features of the remaining claims 2 and 4 to 9 are identical to the corresponding features of claims 2 and 4 to 9 as granted.

3.5. The description has been adapted to the amended wording of the claims and supplemented with a brief summary of the relevant content of document E1 to comply with the requirements of Rules 27(1)(b) and (c) EPC. The Board is satisfied that these amendments comply with the requirements of Article 123(2) EPC.

3.6. Since the amendments made to the patent clearly limit its scope of protection, the Board is satisfied that no extension of the protection conferred has occurred.

3.7. Accordingly, the patent documents as amended according to the appellant's main request satisfy the requirements of Articles 123(2) and (3) EPC.

4. Document E1 - Availability to the public

Document E1, a booklet containing the programming and operating instructions of the "SYSTEM CNC 25.05 D" of Sieb & Meyer both in German and English, bears the imprint "January 80" on its front page and the heading "software code from November 1980" on the last page of the document. It is therefore reasonable to assume that the booklet was drawn up about twelve years before the priority date (27 July 1992) of the patent in suit. A booklet containing the programming and operating instructions of a device and having the characteristics of document E1 is usually addressed to the users that have purchased the device, and therefore it can be assumed that the booklet was issued for public use. The instruction at the penultimate paragraph on page 21 of document E1 to ask the machine tool manufacturer for optimum parameters, the detailed description in the letter of Sieb & Meyer dated 22 November 1999 as filed by the appellant during the opposition proceedings of the characteristics of the system series "CNC 25.05", of which the system "CNC 25.05 D" constitutes a low cost version (document E1, first sentence on page 12), and the reference in document E2, a patent document published on 18 December 1991 and relating to a high speed precision drilling system, to a "model 35 controller marketed by Sieb & Meyer GmbH" as being "a commercially available unit" (column 27, lines 37 to 40) constitute further indications that the system disclosed in document E1 was intended to be freely available on the market. In these circumstances, the appellant's contention that the booklet was issued by the company Sieb & Meyer for internal use only is not considered convincing. In addition, although there is no evidence as to the exact date at which document E1 was actually made available to the public, a period of time of twelve years is long enough to assume that the document was in any case made available to the public within this twelve-year period. The plausibility of the further contention of the appellant that the booklet might have been kept confidential until at least the priority date of the patent in suit is so low that, in the Board's view, the burden of proof for this contention would be incumbent on the appellant. The appellant, however, has submitted no evidence whatsoever in support of his submissions in this respect.

Accordingly, in the present circumstances the Board is convinced that document E1 was made available to the public before the priority date of the patent in suit and that, consequently, this document is comprised in the state of the art.

5. Appellant's main request - Patentability of the subject matter of the claims

5.1. Procedural matters

In accordance with the requests made by both the appellant and the respondent during the oral proceedings held before the Board (see point II above), the Board deemed it appropriate to exercise its discretion under Article 111(1) EPC to decide itself on the patentability of the subject matter of the claims according to the appellant's main request, even if this issue has not been considered by the opposition division.

5.2. The prior art

It was undisputed by the parties that - if document E1 was considered as a prior art document - the drilling method and the system "CNC 25.05 D" disclosed in this document represents the closest prior art from which the invention defined in any of the independent claims sets out. This system constitutes the operation control system of a drilling machine (page 1, first sentence and page 13, penultimate sentence of either one of the German and English versions) for drilling a workpiece mounted on a worktable by means of a drill tool mounted on a spindle, the drill tool being selected among a plurality of drill tools (see page 20, in particular features (a) and (b)). The control system enables control of the movement of the worktable in a horizontal plane (see the XY servo-drive control on pages 89 and 90) as well as manual and programmable automatic drill tool change (see entry "T1 ÷ T15" on page 4). The control system also includes software for controlling the different operations of the drilling machine (pages 3 to 7 and 12), and in particular includes data source identifying each of the selectable drill tools by the corresponding drill diameter and assigning to each of the drill tools a predetermined value for each of a plurality of parameters, which values are input in the control system beforehand (pages 20 and 21 and the example on page 24). The parameters include, among others, the dwell time, i.e. the delay in initiating the drill stroke after positioning of the hole drilling location relative to the drill tool (page 21, penultimate paragraph). Thus, the drilling control operation of the system disclosed in document E1 results in a sequence of drilling operations each carried out with a selected one of the available drill tools, the dwell time of each of the drilling operations being determined by the drill tool selected for the corresponding drilling operation.

Document E2 discloses an automatic drilling apparatus for precision drilling of workpieces such as printed circuit boards, the apparatus comprising a tool changer and a computer controller (abstract together with column 4, lines 32 to 36 and column 27, lines 33 to 47).

5.3. Independent claim 3

The Board will deal with independent claim 3 first for reasons of simplicity.

It follows from the analysis of document E1 in point 5.2 above that the operation of the control system disclosed in the document results in a method of drilling a workpiece using a drilling machine, from which the method defined in independent claim 3 differs essentially in that the plurality of dwell times available for controlling the drilling operation vary not just according to one drilling parameter, i.e. according to the selected drill tool identified by its drill diameter, but according to at least two drilling parameters, the automatic selection of the dwell time corresponding to a set of conditions of a drilling operation being carried out in accordance with the at least two drilling parameters in order to obtain a satisfactory degree of hole placement accuracy and hole quality of the hole drilled during the drilling operation while optimizing the speed with which the drilling operation is performed.

According to the appellant and as discussed in the patent specification (column 2, lines 25 to 29 and column 5, line 52 to column 6, line 2), the technical effect achieved by the distinguishing features identified above is a larger degree of freedom in the selection of the dwell times so as to allow optimization of the drilling rate while at the same time achieving a satisfactory placement accuracy and quality of the drill holes.

Accordingly, the objective problem solved by the method defined in independent claim 3 with respect to document E1 as the closest prior art is the optimization of the throughput of the drilling machine while at the same time achieving a satisfactory degree of hole placement accuracy and hole quality.

The skilled person, faced with the objective problem formulated above, would understand that the use in document E1 of a different dwell time for each drill tool inherently achieves a predetermined degree of hole placement accuracy and hole quality and a predetermined hole drilling rate. However, the control system of document E1 is designed to accept as an input one single dwell time for each drill tool (page 21, lines 1 to 12), and there is no teaching or indication in the prior art that would lead the skilled person to modify the operation of the control system of document E1 so as to arrive to the drilling method according to claim 3. In particular, even if it were assumed that the skilled person would recognise in the indication in document E1 requiring the operator to ask the machine tool manufacturer "for the optimum dwell times" (page 21, penultimate paragraph) a possibility of improving the accuracy and quality of the drill holes and/or the throughput of the machine, he would then at the most consider the optimization of the dwell time and therefore the drill precision and the drill speed associated with each individual drill tool. This procedure, however, would result in the replacement of the set of dwell times stored in the control system by the new set of optimized dwell times which would in turn be automatically selected according to one single parameter, i.e. according to the drill tool selected for each drilling operation.

The respondent has submitted that the skilled person would regard as an imperative the use of the appropriate dwell time in the drilling operation of each hole in order to drill all holes with the desired degree of placement accuracy and quality, and that for this reason the skilled person would consider, without the exercise of any inventive ingenuity, automatically varying the dwell time assigned to a specific drill tool according to a second parameter relating to the placement accuracy and quality of the hole to be drilled. This line of argument, however, does not persuade the Board as no hint can be found in the prior art that would lead the skilled person to depart from assigning a predetermined dwell time, and therefore a predetermined drilling speed and a predetermined degree of accuracy, to all the drilling operations carried out with the same drill tool as taught in document E1 in order to solve the problem formulated above. On the contrary, the respondent's submission runs counter the disclosure of document E1 that all parameters that might have an influence on the accuracy and the speed of the drilling operation, such as the dwell time and the remaining drilling parameters considered in the document (see parameters (b), (c) and (d) on page 20), are all unequivocally determined by the drill tool selected to carry out the drilling operation. In addition, document E2, the other one of the documents considered during the proceedings, does neither disclose nor suggest drilling with varying dwell times and therefore does not provide any teaching in this respect.

The Board concludes that, having regard to the prior art considered by the parties, the skilled person would not have reached the subject matter of claim 3 in an obvious way. Therefore, the subject matter of independent claim 3 of the main request involves an inventive step within the meaning of Article 56 EPC.

5.4. Independent claim 1

The drilling method defined in claim 1 differs from the method disclosed in document E1 and referred to in points 5.2 and 5.3 above, apart from the straightforward application to the drilling of printed circuit boards as known from document E2, essentially in that the dwell time depends upon and is determined not only by the selected drill tool identified by its drill diameter, but also at least by a second parameter including a desired degree of placement accuracy of the hole to be drilled.

The technical effect achieved by these distinguishing features is the same as that achieved in respect of the distinguishing features of independent claim 3 (see point 5.3 above). Accordingly, the objective problem is the same as that formulated in point 5.3 above with respect to the subject matter of claim 3.

As pointed out in point 5.3 above, however, none of the prior art references would lead the skilled person to vary the dwell time of a drilling operation to be carried out with a selected one of the drill tools according to an additional drilling parameter, still less according to the degree of placement accuracy of the hole to be drilled.

For this reason, also the subject matter of claim 1 of the main request can be considered to involve an inventive step within the meaning of Article 56 EPC.

5.5. Independent claim 10

The disclosure of document E1 relative to the operation control system of a drilling machine results in a drilling machine for drilling a workpiece comprising a controller, from which the drilling machine defined in independent claim 10 differs essentially in that the dwell times contained in the data source stored in the controller vary not only in accordance with the diameter of the drill tool used in the drilling operation, but also in accordance with a desired degree of placement accuracy of the hole to be drilled so as to optimize the efficiency of the drilling machine and the quality of the holes drilled.

The prior art would not lead the skilled person to a drilling machine having the features of claim 10 for reasons analogous to those put forward in point 5.4 above with regard to the subject matter of claim 1. For this reason, also the subject matter of independent claim 10 of the main request can be considered to involve an inventive step within the meaning of Article 56 EPC.

5.6. For the above reasons, independent claims 1, 3 and 10. according to the appellant's main request are allowable under Article 52 EPC. Dependent claims 2 and 4 to 9 are also allowable by virtue of their dependency on allowable independent claims 1 and 3, respectively.

6. Auxiliary requests

Since the subject matter of the claims according to the main request is allowable, consideration of that of the auxiliary requests is not necessary.

7. The Board concludes that the patent as amended according to the appellant's main request and the invention to which it relates meet the requirements of the convention. Accordingly, the patent can be maintained as amended (Article 102(3) EPC).