T 0950/05 12-07-2007

1. Late filing of documents

1.1 Document D1'

Document D1' was introduced into the opposition proceedings by the Opposition Division. This document is referred to in document D1 at page 3, lines 16 to 20, as showing a module for use in the printhead of document D1.

In view of the relevance of document D1' to the decision under appeal, the Opposition Division correctly exercised their discretion in introducing this document into the proceedings.

1.2 Document D7

Document D7 was not considered in the proceedings before the Opposition Division and was introduced into the present proceedings with the statement of grounds of appeal.

In the decision under appeal, the patent in suit was maintained in amended form, claim 1 having been amended so as to make clear an otherwise unclear feature concerning the separation of the orifices.

The disclosure of document D7 is relevant to this feature. During the course of the appeal proceedings, the respondent had ample time to consider this document. The Board accordingly considers it appropriate to exercise their discretion and admit document D7 into the present proceedings.

2. Main Request

2.1 Amendments

The opponent is the sole appellant against an interlocutory decision maintaining a patent in amended form. The patent proprietor is primarily restricted during the appeal proceedings to defending the patent in the form in which it was maintained by the Opposition Division in its interlocutory decision (cf. decision G 9/92 (OJ EPO 1994, 875); point 16 of the Reasons). Amendments proposed by the patent proprietor as a party to the proceedings as of right under Article 107 EPC, second sentence, may be rejected as inadmissible by the Board of Appeal if they are neither appropriate nor necessary (decision G 9/92; point 16 of the Reasons).

The reference to the ink jet printing head being a piezoelectric ink jet printing head, and the expression "along the direction of the print lines", which qualifies the distance of separation of the orifices in claim 1 as maintained in the decision under appeal, are omitted from claim 1. The omission of these features allows the claim to cover print heads and arrangements of the orifices that would not be covered by claim 1 as maintained in the decision under appeal.

The omission of these features thus gives rise to a reformatio in peius to the disadvantage of the appellant. In the Board's judgement, these amendments are therefore neither appropriate nor necessary and the request has to be rejected as inadmissible.

3. First Auxiliary Request

3.1 Novelty

Document D1 discloses, with particular reference to Figure 2(a), (b) and (c), a printhead comprising layers of modules grouped in stacks. As stated at page 3, lines 16 to 20, the modules may be those of document D1' or D2. The disclosure of document D1 must thus be read in conjunction with that of documents D1' and D2 as regards the construction of the modules.

Document D2 discloses, with particular reference to Figure 1(a), (b) and (c), such a module having rectangular ink channels, the longer edge of the channels extending normal to the plane containing the channel axes (page 4, lines 6 to 8). As disclosed at page 4, lines 8 to 10, the aspect ratio of the channels is "typically 3 to 30". In addition, it is disclosed at page 4, lines 36 to 38, that the aspect ratio of the actuator wall, that is, the wall separating the channels, is "typically 3-30 or more".

The use of an aspect ratio for the channels and actuator walls of 30 inevitably results in the orifices being arranged in a pattern such that adjacent parallel lines on the print medium are served by orifices that have different positions in the array along the direction of the print lines, and are separated along the direction of the print lines by a distance that is at least an order of magnitude greater than the distance between adjacent orifices in a direction perpendicular to the print-line direction.

It was argued on behalf of the respondent that the teaching in document D2 at page 1, lines 37 to 43, encourages the person skilled in the art to reduce the distance between the rows of modules. In the light of this teaching, the aspect ratio of 3, rather than 30, would be selected. This cannot be accepted in the context of the consideration of the question of novelty. Document D2 provides a clear teaching of an aspect ratio of 30 and indicates at page 4, lines 5 and 6, that this feature enables a high density of packing of the ink channels. There is thus no reason for the skilled reader of document D2 to ignore this disclosure.

The subject-matter of claim 1 thus lacks novelty in view of the disclosure of document D1 read in conjunction with that of document D2.

4. Second and Third Auxiliary Requests

4.1 Clarity

Claim 1 (both requests) is directed to "a method for avoiding or at least diminishing the disadvantageous effects of web weave and poor line merging". As explained in paragraph [0020] of the patent in suit, the effects of web weave can be reduced by minimizing the spacing along the direction of the print lines between orifices serving adjacent print lines. The effects of poor line merging, however, may be mitigated by allowing as much time as possible to pass between drop formation of adjacent print lines (see paragraph [0027] and Figure 5 of the patent in suit).

Whilst claim 1 specifies a minimum value for the distance between adjacent orifices in a direction perpendicular to the print line-direction, no upper limit is specified. Thus, whilst the features of the claim may be regarded as potentially addressing the problem of poor line merging, the claim does not specify any technical features which would contribute to a solution to the problem of poor drop placement resulting from web weave.

In addition, the effect of poor line merging, as discussed in the patent in suit in paragraphs [0022] to [0024], is not only dependant upon orifice spacing, but also, for example, web speed, absorbency of the substrate and ink viscosity.

It was suggested on behalf of the respondent that decisions G 2/88 and G 6/88 of the Enlarged Board of Appeal are applicable to claim 1. In decision G 6/88, the question referred to the Enlarged Board was answered as follows: "a claim to the use of a known compound for a particular purpose, which is based on a technical effect which is described in the patent, should be interpreted as including that technical effect as a functional technical feature, and is accordingly not open to objection under Article 54(1) EPC provided that such technical feature has not previously been made available to the public".

These decisions do not, however, apply in the present case. Claim 1 fails to specify a "particular purpose, which is based on a technical effect" and merely refers to the alleged advantage of "avoiding or at least diminishing the disadvantageous effects of web weave and poor line merging". In fact, the purpose of the claimed use is forming a printed image, which is not distinguishable from the purpose of the prior art.

Claim 1 thus fails to specify the technical features of the method which are essential for solving the technical problem with which the patent in suit is concerned. The requirements of Article 84 EPC are thus not satisfied.

5. Fourth Auxiliary Request

5.1 Novelty

As shown in, for example, Figure 2(a) of document D1, each of the orifice plates is associated with a print-head module that prints a swath along the web, the swath being narrower than the target width. In addition, the printhead of document D1 is intended for printing on a moving web (see page 2, line 2), and is piezoelectrically actuated (see page 3, line 16).

The features which distinguish claim 1 from claim 1 of the first auxiliary request are thus also known from document D1, so that the subject-matter of the claim lacks novelty.

6. Fifth Auxiliary Request

6.1 As compared with claim 1 as maintained in the decision under appeal, claim 1 omits, inter alia, the wording "along the direction of the print lines" (second occurrence). Thus, claim 1 as maintained in the decision under appeal specifies the distance between orifices serving adjacent print lines in terms of the distance as measured along the direction of the print lines. However, claim 1 of the present request does not specify how this distance is to be measured, so that it must be assumed that it is the actual distance between the orifices that is intended.

Orifices serving adjacent parallel lines that are separated along the direction of the print lines by a distance that is somewhat less than an order of magnitude greater than the distance between adjacent orifices in a direction perpendicular to the print-line direction may, nevertheless, be separated by a distance (measured directly) that is at least an order of magnitude greater than the distance between adjacent orifices in a direction perpendicular to the print-line direction.

Thus, printheads which would not fall under claim 1 as maintained in the decision under appeal may fall under claim 1 of the present request.

The omission of this wording thus gives rise to a reformatio in peius to the disadvantage of the appellant. This amendment therefore has to be rejected as inadmissible.

7. Sixth Auxiliary Request

7.1 Amendments

Claim 1 is amended to specify that adjacent parallel lines on the print medium are served by orifices that are separated along the direction of the print lines by a distance that is no more than two orders of magnitude greater than the distance between adjacent orifices in a direction perpendicular to the print-line direction.

In the application as filed, there is a disclosure in the paragraph bridging pages 9 and 10 that, "in the example of figures 10 through 12, the distance along the web direction … is between 1.2 and 2.0 inches for every adjacent pair of printing line orifices (which is more than an order of magnitude and almost two orders of magnitude larger than the orifice spacing - 1/50 inch - in a given array module)". There is, however, no disclosure to the effect that a ratio of two orders of magnitude may constitute an upper limit or that such a ratio is applicable to printing heads other than that with which this paragraph is concerned.

The amendment thus does not satisfy the requirements of Article 123(2) EPC.

8. Seventh Auxiliary Request

8.1 Amendments

Claim 1 is amended to specify that the ratio between the largest distance between adjacent orifices in the print-line direction and the smallest distance between adjacent orifices in the print-line direction is no greater than 1.67:1.

In the application as filed, there is a disclosure in the paragraph bridging pages 9 and 10 that, "in the case of figures 11 and 12, the ratio is 1.67". There is, however, no indication that this ratio may constitute an upper limit or that such a ratio is applicable to printing heads other than that with which this paragraph is concerned.

The amendment thus does not satisfy the requirements of Article 123(2) EPC.

9. Eighth Auxiliary Request

9.1 Inventive Step

9.1.1 Closest Prior Art

Document D7 discloses, with particular reference to the embodiment of Figures 3 and 4, a first embodiment of a single-pass piezoelectric ink jet printing head 10, the printing head comprising an array of ink jet outlets sufficient to cover a target width of a print substrate at a predetermined resolution, and an orifice plate 90, the orifices of which are arranged in a pattern such that adjacent parallel lines on the print medium are served by orifices that have different positions in the pattern along the direction of the print lines (see column 4, lines 35 to 42).

Figures 6 and 7 of document D7, as mentioned at column 5, lines 61 to 64, show a printhead comprising modules arranged as in the first embodiment. The orifices serving adjacent print lines are separated along the direction of the print lines by about 0.34 to 0.4 inch (column 6, line 39). Adjacent orifices in a direction perpendicular to the print-line direction are separated by about 0.020 inch (column 5, lines 63 and 64). The ratio between these dimensions as specified in claim 1 is thus greater than an order of magnitude.

As disclosed at column 6, line 1 of document D7, a print image of about 10 1/4 inches may be produced using the embodiment of Figures 6 and 7.

The subject-matter of claim 1 is distinguished over the disclosure of this document solely in that the printhead comprises a plurality of orifice plates, each of the orifice plates serving some but not all of the area to be printed.

9.1.2 Problem to be Solved

It was suggested on behalf of the respondent that the problem to be solved may be regarded as being to overcome the disadvantages resulting from web weave and poor line merging. However, this problem is not addressed by the use of multiple orifice plates.

The problem to be solved may be regarded as being to enable single pass printing of print images having a greater width.

9.1.3 Solution

This problem can be solved by either increasing the width of the printing head or by arranging two or more of the printheads as known from document D5 side by side. The choice between these two alternatives is a trivial matter depending on manufacturing considerations. The use of two or more of the known printing heads side by side would result in a printing head comprising a plurality of orifice plates, each of the orifice plates serving some but not all of the area to be printed.

The subject-matter of claim 1 thus does not involve an inventive step within the meaning of Article 56 EPC.