T 0237/96 22-04-1998

1. The appeal is admissible.

2. Refusal by the Examining Division to consent to the amendment to claim 1 proposed by the appellant on 29. August 1994

2.1. Under Rule 86(3) EPC, after reply to the first communication from the Examining Division (in this case by appellant's letter dated 15 June 1993), amendment of a European patent application cannot be made without the consent of the Examining Division and is therefore matter of discretion for the latter.

According to consistent case law of the Boards of Appeal of the EPO, an Examining Division when exercising such discretion must consider all relevant factors of the specific case and balance in particular the applicant's interest in obtaining an adequate protection for his invention and the EPO's interest in bringing the examination to a close in an effective and speedy way. Furthermore, once an Examining Division has exercised such discretion, a Board of Appeal should only overrule it if it comes to the conclusion either that the Examining Division has not exercised its discretion in accordance with the right principles or that it has exercised its discretion in an unreasonable way and has thus exceeded the proper limit of its discretion; see in particular the decision of the Enlarged Board of Appeal G 7/93, OJ EPO 1994, 775, points 2.5 and 2.6 of the Reasons and decision T 182/88, OJ EPO 1990, 287, points 3 and 4 of the Reasons.

2.2. The Examining Division did not found its decision on the sole fact that appellant's request for amending claim 1 had been filed later than the issuance of the communication under Rule 51(4) EPC which was based on a version previously accepted by him. The Examining Division also felt that the reason given for filing the amendment - namely that it had been noted that the embodiment of Figure 2 was not covered by the claims as proposed for grant - was not consistent with the appellant's previous submissions in his responses to the two communications of the Examining Division which preceded the issuance of the communication under Rule 51(4) EPC.

The appellant had indeed in these responses entirely concentrated his argumentation in support of inventive step on the merits of the embodiment of Figures 6 to 8 with the controlling of a DC component of the alternating voltage supplied to the electrostatic separating means. He had also expressly stated that the embodiments of Figures 2 to 5 which involved instead control of the duty ratio of an AC voltage were not to be regarded as embodiments in accordance with the invention; see appellant's letters dated 15 June 1993, page 3, third paragraph and 9 February 1994, page 2, sixth paragraph.

2.3. The Examining Division also emphasized that, had it given its consent to the amended version of the claim, the examination should have been re-started from the beginning, which, given the prima facie lack of clarity of the claim, would have led to a considerable delay.

Whether resuming examination could have been expected to lead to a considerable delay or not is of course a matter of judgement and experience.

To refuse minor amendments of merely editorial nature, or amendments relating to aspects of the invention of no relevance to the assessment of the patentability of the claimed subject-matter, if such amendments were clearly acceptable under Articles 84 and 123(2) EPC, may for instance not be considered reasonable of an Examining Division.

In the present circumstances, however, there is little doubt that the feature of a "DC component" of the alternating voltage being supplied to the electrostatic separating means, which was removed from claim 1 by the appellant after issuance of the communication under Rule 51(4) EPC, actually played a central role for the assessment of inventive step in the examining procedure up to the issuance of the communication under Rule 51(4) EPC. The appellant did not however in his letter of 29 August 1994 submit any reasoned argument whatsoever in support of the patentability of the subject-matter of the proposed broader claim. Such patentability clearly could not follow from his earlier submissions, which were all expressly directed to the embodiment with the control of a DC component only.

Concerning the prima facie lack of clarity of amended claim 1, which was also alleged by the Examining Division to justify its decision to refuse its consent to the amendment, the reference to "a component" of a periodic voltage which has a certain polarity and which is controlled so as to achieve a constant difference of the positive and negative currents supplied to the separating means can, in the Board's judgement, hardly be considered to clearly encompass the controlling of the duty ratio of an alternating voltage disclosed in the description with reference to Figures 2 to 5.

Moreover, when the duty ratio of an alternating voltage is varied, the waveform of the voltage is necessarily changed, and it cannot therefore be maintained as is set out at the end of the claim.

2.4. For these reasons, the Examining Division does not in the circumstances appear to have exercised its discretion under Rule 86(3) EPC in a wrong or unreasonable manner.

2.5. The refusal by the Examining Division to admit the amended claim 1 into the procedure is not considered either to have infringed against the provisions of Article 113(2) EPC, as was further submitted by the appellant.

Article 113(2) EPC indeed specifies that a decision on a European patent application can only be based on the text submitted or agreed by the applicant, and the Examining Division would certainly have offended against these provisions, had it decided to grant a patent or refused the application on the basis of the application documents indicated in its communication pursuant to Rule 51(4) EPC, to which the appellant no longer agreed.

Article 113(2) EPC cannot however be interpreted in the sense that the Examining Division is bound to accept any amendment which the applicant might propose, only to ensure that there is a version approved by him.

In circumstances in which, like in the present case, amendments proposed by the applicant are not allowed by the Examining Division by virtue of Rule 86(3) EPC and the applicant does not give its agreement to any other version of the application documents, the established practice of the EPO, sanctioned by consistent case law, is to refuse the application on the ground that there is no version approved by the applicant in the sense of Article 113(2) EPC, on which a patent could be granted.

3. Appellant's main request

3.1. Claims 1 to 14 of the set of claims according to appellant's main request correspond to the claims on the basis of which the Examining Division intended to grant a patent, as indicated in its communication pursuant to Rule 51(4) EPC, the expression "periodic voltage" having however being amended to "alternating voltage" throughout the claims for consistency with the description.

The Board sees no reason to question the Examining Division's conclusion, reflected by its intention to grant a patent, that these claims fulfilled the requirements of the Convention.

The subject-matter of independent claim 1 was indeed disclosed originally in relation with the embodiment of Figures 6 to 8.

The nearest prior art as defined in the preamble of independent claim 1 is constituted by the apparatus disclosed in either of documents JP-A-60 220 381 or JP-A-62 043 681 as referred to in the introductory portion of the present description. The technical problem solved by the distinguishing features set out in the characterising portion of claim 1, namely the provision of a DC component having a polarity opposite to the polarity of a voltage applied to the transfer means and the controlling of the level of said DC components so that the current difference between the positive component and the negative component of the current supplied to the separating means is constant while the wave form of the alternating voltage supplied to the separating means is maintained, is to guarantee a proper separation of the transfer material from the photosensitive member under all circumstances, in particular independently of whether the transfer material comprises toner free or toner carrying portions. None of the documents presently on the file discloses nor suggests these features, nor addresses the technical problem underlying the invention and the interest of controlling the current difference between the positive and the negative components of the current supplied to the separating means.

3.2. The preamble of additional independent claim 15 is identical to the preamble of independent claim 1 and its characterising portion is comprised of a combination of the features of dependent claims 6 and 7 as originally filed. Independent claim 15 thus defines the embodiment of the invention originally disclosed in relation to Figures 2 and 5, which is distinguished from the embodiment defined in claim 1 in that the current difference between the positive and the negative components of the current supplied to the separating means is maintained constant by controlling the duty ratio of the alternating voltage instead of controlling the level of the DC component.

From the detailed explanations given by the appellant in his letter dated 24 March 1998 as supported by the attached English translation of document JP-A-62 043 681, it is immediately apparent that the reasons which justify the non-obviousness of the subject-matter of independent claim 1 also apply to the subject-matter of independent claim 15.

Document JP-A-62 043 681 indeed discloses two distinct embodiments in which the duty ratio of the alternating voltage supplied to the separating means is either 1:1 (see Figure 2) or 1:3 (see Figure 4). There is however no hint in the document to control the duty ratio in a single embodiment, for any purpose whatsoever.

3.3. The version of the description which formed the basis of the Examining Division's communication under Rule 51(4) EPC has been maintained unamended. Obviously, the generic reference made on page 6a, line 2 to claim 1 should be corrected so as to refer also to independent claim 15. No further adaptation is considered necessary, because the passage from line 17 of page 10 to line 26 of page 11, in particular its last sentence, clearly implies that the embodiment of Figure 2, which is compared there to the prior art system, is part of the invention.

3.4. Thus, in contrast with the situation which prevailed when the Examining Division took its decision to refuse the application, in which in particular the amendment brought to claim 1 raised new issues as to clarity and was not supported by any argumentation by the appellant in favour of the inventive step involved by the amended subject-matter, it is now clear that the present amendment, consisting essentially in an additional independent claim directed to a further embodiment of the invention disclosed in the description, is immediately acceptable.

The Board, exercising its powers within the competence of the Examining Division as provided for in Article 111 EPC therefore gives its consent under Rule 86(3) EPC to the claims being amended in accordance with appellant's main request, and confirms that a patent can be granted on the basis of these claims.

4. Since the Board could not identify any substantial procedural violation by the Examining Division (see above, point 2 of the Reasons), appellant's request for reimbursement of the appeal fees is dismissed.

His auxiliary request for oral proceedings was conditional to a patent not being granted on the basis of his main request, and it need not therefore be considered.