T 1099/22 16-07-2024

I. The appeal lies from the decision of the opposition division to revoke European patent No. 3 224 025.

II. Two oppositions were filed against the patent as a whole. The opposition by respondent I (opponent 1) was based on the grounds for opposition under Article 100(a) together with Article 54(1) EPC (lack of novelty) and Article 56 EPC (lack of inventive step), under Article 100(b) EPC and under Article 100(c) EPC. The opposition by respondent II (opponent 2) was based on the grounds for opposition under Article 100(a) together with Article 54(1) EPC (lack of novelty) and Article 56 EPC (lack of inventive step), and under Article 100(c) EPC.

III. In the decision under appeal, the opposition division came to the following conclusions.

- The subject-matter of claim 1 as amended according to the main request filed in reply to the notices of opposition extended beyond the content of the application as filed for three different reasons (i) to (iii).

- Auxiliary requests 1 to 7 filed with letter dated 12 November 2021 were admitted into the opposition proceedings.

- The subject-matter of claim 1 as amended according to each of auxiliary requests 1 to 7 extended beyond the content of the application as filed.

- Auxiliary requests 8 and 9 filed during the oral proceedings held on 23 November 2021 were not admitted into the opposition proceedings.

IV. Oral proceedings before the board were held on 16 July 2024.

V. The appellant (patent proprietor) requested that:

- the decision under appeal be set aside and that the patent be maintained as amended on the basis of the claims of the main request underlying the decision under appeal or,

- alternatively, on the basis of the claims of one of auxiliary requests 1 to 9 filed with the statement of grounds of appeal (corresponding to auxiliary requests 1 to 9 underlying the decision under appeal),

- the decision under appeal be set aside and the patent be maintained as amended on the basis of the claims of one of auxiliary requests 10 to 18 filed with letter dated 9 February 2023 if the board were to admit respondent II's new objection of intermediate generalisation into the appeal proceedings,

- the case be remitted to the opposition division for further prosecution if the board were to find the claims of the main request or any of the auxiliary requests 1 to 18 to meet the requirements of Article 123(2) EPC, in so far as the reasons (i), (ii) and (iii) were concerned.

The respondents I and II (opponents 1 and 2) requested:

- that the appeal be dismissed,

- by way of auxiliary request that the case be remitted to the opposition division for further prosecution,

- not to admit auxiliary requests 8 and 9 into the appeal proceedings.

Respondent II (opponent 2) also requested not to admit auxiliary requests 10 to 18 into the appeal proceedings.

VI. Independent claim 1 of the main request has the following wording (the claim feature numbering used by the opposition division appears in square brackets):

"[1.1] Apparatus (1) for producing an object (2) by means of additive manufacturing, comprising:

- [1.2] a process chamber (3) for receiving a bath of material (4) which can be solidified by exposure to electromagnetic radiation (72);

- [1.3] a support (5) for positioning the object (2) in relation to the surface level (L) of the bath of material (4);

- [1.4] a solidifying device (7) for solidifying a selective layer-part of the material on the surface level (L) by means of electromagnetic radiation (71);

- [1.5] a registering device (81) for registering a characteristic related to the surface level (L) of the bath of material (4); and

- [1.6] a control unit (91) connected to the registering device (81) and arranged for using the characteristic obtained by the registering device (81) for controlling the position of the electromagnetic radiation (72) emitted by the solidifying device (7);

- [1.7] a deflector unit (74), which is arranged for deflecting electromagnetic radiation (72) emitted by the solidifying device (7) towards the surface level (L) of the bath of material (4);

[1.8] wherein the registering device (81) comprises at least one imaging device, in particular an optical imaging device, such as a camera unit; and

[1.9] wherein the apparatus (1) comprises a plurality of calibration elements (82, 82a, 82b, 82c, 8d) provided on or near the support (5), [1.10a] wherein the control means are arranged for controlling the solidifying device (7) based on a geometric characteristic of the plurality of calibration elements (82, 82a, 82b, 82c, 8d) registered by the registering device (81) [1.10b] between the manufacturing of different individual layers of the object by means of the solidifying of a selective layer-part of the material on the surface level (L),

[1.11a] wherein the imaging device is arranged such that the characteristic is registered via the deflector unit (74),

[1.12] wherein the imaging device is arranged for making an image of the plurality of calibration elements (82, 82a, 82b, 82c, 8d), and wherein the registering device (81) is arranged for determining the geometric characteristic of the plurality of calibration elements (82, 82a, 82b, 82c, 8d), providing information on the geometric position of the calibration elements with respect to the surface level of the bath of material, based on the image obtained by the imaging device,

[1.13] wherein the imaging device is arranged such that an optical path (71) of the imaging device, during use of the imaging device, at least partly coincides with an optical path (71) of the electromagnetic radiation (72) generated by the solidifying device (7), during use of the solidifying device (7)."

VII. Independent claim 1 of auxiliary request 1 has the following amendment to feature 1.9 (emphasis by the board).

"[1.9] wherein the apparatus (1) comprises a plurality of calibration elements (82, 82a, 82b, 82c, 8d) provided [deleted: on or] near the support (5),"

VIII. Independent claim 1 of auxiliary request 2 is identical to independent claim 1 of the main request except for the following amendments to features 1.10a and 1.10b (emphasis by the board).

"[1.10a] wherein the control means are arranged for controlling the solidifying device (7) based on a geometric characteristic of the plurality of calibration elements (82, 82a, 82b, 82c, 8d) registered by the registering device (81), during manufacturing of the object, [1.10b] between the manufacturing of different individual layers of the object by means of the solidifying of a selective layer-part of the material on the surface level (L) for using the characteristic for controlling the position of the electromagnetic radiation emitted by the solidifying device during manufacturing of a subsequent layer,"

IX. Independent claim 1 of auxiliary request 3 combines the amendments of auxiliary requests 1 and 2. The independent claims 1 of auxiliary requests 4 to 7 have identical wording to independent claim 1 of the main request, auxiliary request 1, auxiliary request 2 and auxiliary request 3, respectively.

X. Compared to independent claim 1 of the main request, independent claim 1 of auxiliary request 8 has the following amendments to feature 1.10a and 1.12 (emphasis by the board).

"[1.10a] wherein the control [deleted: means are] unit is arranged for controlling the solidifying device (7) based on a geometric characteristic of each of the plurality of calibration elements (82, 82a, 82b, 82c, 8d) registered by the registering device (81)"

"[1.12] wherein the imaging device is arranged for making an image of each of the plurality of calibration elements (82, 82a, 82b, 82c, 8d), and wherein the registering device (81) is arranged for determining the geometric characteristic of each of the plurality of calibration elements (82, 82a, 82b, 82c, 8d), providing information on the geometric position of each of the calibration elements with respect to the surface level of the bath of material, based on the image obtained by the imaging device,"

XI. Compared to independent claim 1 of auxiliary request 3, independent claim 1 of auxiliary request 9 has the following amendments to feature 1.10a, 1.11a and 1.12 (emphasis by the board).

"[1.10a] wherein the control [deleted: means are] unit is arranged for controlling the solidifying device (7) based on a geometric characteristic of each calibration element of the plurality of calibration elements (82, 82a, 82b, 82c, 8d) registered by the registering device (81), during manufacturing of the object,"

"[1.11a] wherein the imaging device is arranged such that the characteristic of said each calibration element is registered via the deflector unit (74),"

"[1.12] wherein the imaging device is arranged for making a[deleted: n] respective image of said each calibration element of the plurality of calibration elements (82, 82a, 82b, 82c, 8d), and wherein the registering device (81) is arranged for determining the geometric characteristic of said each calibration element of the plurality of calibration elements (82, 82a, 82b, 82c, 8d), providing information on the geometric position of said each calibration element of the plurality of calibration elements with respect to the surface level of the bath of material, based on the respective image obtained by the imaging device,"

XII. The appellant's submissions may be summarised as follows.

Main request - Article 123(2) EPC

The opposition division was incorrect in its finding that the requirements of Article 123(2) EPC were not fulfilled.

- Reason (i)

Feature 1.12 of claim 1 of the main request had basis in the application as filed. On page 41, lines 3 to 5 of the application as filed, it was disclosed that the camera unit was arranged for making one or more images of calibration elements. By the use of this wording, the application as filed disclosed a first possibility that the camera was arranged for making one image of plural calibration elements and a second possibility that the camera was arranged for making several images of plural calibration elements. This had to be read together with the next sentence according to which the one or more images of one or more of the calibration elements obtained by the registering device were processed by the registering device itself, or were fed to the control unit for being processed there. Hence, this disclosure was not limited to an embodiment comprising a camera unit, but to any imaging device. Although the passages mentioned were part of the description of an embodiment that did not fall within the scope of claim 1 of the main request, the passage extending from page 41, line 32 to page 42, line 1 of the application as filed indicated that the aforementioned disclosure was not limited to the embodiment of Figure 1, but also to the apparatus of the embodiment of Figure 2. The embodiment of Figure 2 largely corresponded to that of Figure 1 and was thus also arranged for making one image of plural calibration elements. Respondent I's statement that the skilled person would understand that the passages cited in relation to the embodiment of Figure 1 did not apply to the embodiment of Figure 2 was a mere allegation without presenting serious doubts, substantiated by verifiable facts. Furthermore, the mere fact that the imaging device of the embodiment of Figure 2 had a different field of view compared to the embodiment of Figure 1 did not necessarily imply that the imaging device of Figure 2 would not be able to take a single image of plural calibration elements. Its field of view was not reduced to the extent that the respondents claimed it to be. On the contrary, it followed from page 42, lines 10 to 13 and page 5, lines 29 to 31 of the application as filed that an image could be obtained of at least a part of the calibration area. Either side of the bath of powdered material as shown in Figures 3 and 4 of the application as filed might be considered a calibration area provided with plural calibration elements. Nothing implied that the calibration area was restricted to a single calibration element. Reference was further made to claim 6 and page 5, lines 27 to 33 of the application as filed. The alternative embodiment as described on page 41, lines 13 to 31 of the application as filed was not according to claim 1 as granted, nor to claim 1 of the main request or to claim 1 of any of the auxiliary requests. Therefore, this passage was irrelevant in the present appeal proceedings. It should further be considered that the consideration whether the application as filed disclosed how an image of a plurality of calibration elements could be taken was not a matter of Article 123(2) EPC.

- Reason (ii)

Feature 1.10a had basis in the application as filed. The appellant agreed with the statement of the opposition division that a calibration element, by definition, had a geometric characteristic. Hence, a plurality of calibration elements together also, by definition, had a geometric characteristic. In this regard, attention was drawn to page 4, lines 4 to 5 and and page 5, lines 1 to 3 of the application as filed. In other words, an example of a geometric characteristic of plural calibration elements together might be a distance between two lines of two calibration elements. In addition to the relative distance, each of the calibration elements 82a-f shown in Figures 3 and 4 of the application as filed had a geometric characteristic in the form of its XY-position. It was further pointed out that the passages on page 4, lines 1 to 3 and on page 4, lines 3 to 5 of the application as filed were not inextricably linked, nor was there an exclusive link with the passage on page 5, lines 1 to 3 of the application as filed, which did not mention the calibration area. The passage on page 4, lines 27 to 29 of the application as filed merely disclosed an alternative embodiment without limiting the disclosure as regards page 4, lines 4 to 5 and page 5, lines 1 to 3 of the application as filed. The creation of the characteristic by the solidifying device was merely an optional requirement suggested on page 5, lines 5 to 6 of the application as filed.

Auxiliary requests 1 to 7

For the same reasons, the requirements of Article 123(2) EPC were fulfilled for claim 1 of each of auxiliary requests 1 to 7.

Auxiliary requests 8 and 9

Auxiliary requests 8 and 9 prima facie met the requirements of Article 123(2) EPC. The board was requested to admit these requests under Rule 12(6) RPBA into the appeal proceedings.

Independent claim 1 of auxiliary request 8 contained limitations that had basis on page 41, lines 4 to 9 and on page 5, lines 14 to 15 of the application as filed. The definite article at the end of feature 1.12 referred to "an image of each of the plurality of calibration elements" at the beginning of feature 1.12. In view of the wording of claim 1 of auxiliary request 8 in its entirety, an interpretation wherein only a single image was obtained by the imaging device was illogical. Claim 1 of auxiliary request 8 clearly required that the imaging device was arranged for making a plurality of images each comprising an image of a calibration element. The amendments therefore solved the objections raised in the context of the main request.

The limitations introduced in independent claim 1 of auxiliary request 9 were based on page 4, lines 14 to 18, on page 6, lines 11 to 15 and on page 41, lines 5 to 12 of the application as filed. By virtue of the wording "[i]n particular" in said last passage, it was clear that the embodiment was not limited to one geometric characteristic of one calibration element only. The skilled person would derive from the application as filed that the characteristic of each calibration element was obtained and a respective image of each calibration element was made so that the control of the solidifying device was based on the respective image obtained by the imaging device. Claim 1 of auxiliary request 9 was not limited to an embodiment wherein after each layer a calibration element was registered and, after another layer, another calibration element was registered. An alleged failure of the application as filed to disclose at what time of the process each of the calibration elements were registered was not a matter of Article 123(2) EPC. In this context, particular reference was made to the passages on page 4, lines 19 to 26 and on page 42, lines 17 to 24, whereby the possibility of repeating the registering step directly after the solidifying step was part of an embodiment of the method and was not disclosed as an essential feature. Claim 1 of auxiliary request 9 consistently used the wording "the object" so that it was clear that the usage of the plurality of calibration elements related to the manufacturing of a single object.

XIII. The respondents' submissions may be summarised as follows.

Main request - Article 123(2) EPC

The opposition division was correct in its finding that, at least for the following reasons, claim 1 of the main request did not fulfill the requirements of Article 123(2) EPC.

- Reason (i)

There was no direct and unambiguous disclosure for feature 1.12 of claim 1 of the main request. The sentence on page 41, lines 4 to 5 of the application as filed related to the embodiment shown in Figure 1, in which the camera 81, contrary to what was required by feature 1.11a, was not arranged such that the characteristic was registered via a deflector unit. Therefore, this embodiment did not fall within the scope of the claims. Furthermore, it had to be taken into account that the next sentence referred to "one or more images of one or more of the calibration elements", i.e. one image contained one calibration element and several images contained several calibration elements. This had to be understood in that the registering device 81 of the embodiment of Figure 1 only captured a single calibration element 82, as opposed to the use of a plurality of registering devices for improved accuracy mentioned on page 41, lines 28 to 31 of the application as filed. Following the passage extending from page 41, line 32 to page 42, line 13 of the application as filed, the main difference between the embodiments of Figures 1 and 2 lied in the position of the imaging device 81 in the apparatus. Unlike the alternative use of a plurality of registering devices in the preceding passage, only one imaging device was mentioned here. Already for this reason, the apparatus of Figure 2 must only capture a single calibration element in one image. Separate images were thus required to capture different calibration elements. It also had to be considered that the arrangement of the imaging device 81 shown in Figure 2 and described on page 42, lines 3 to 6 of the application as filed was the reason that its optical path 71 had to be directed via a deflection unit and at least partially coincided with the path of the electromagnetic radiation generated by the solidifying device (see feature 1.13 of claim 1). According to page 5, lines 24 to 33 of the application as filed, such an arrangement had the advantage of giving a more direct feedback. The skilled person would thus understand that the embodiments of Figures 1 and 2 differed in how the imaging device was arranged in the apparatus and, as a consequence, in what was viewed by the imaging device. Hence, the arrangement of the camera unit described in the context of the embodiment of Figure 1 on page 41, lines 4 to 5 could not be read across to the embodiment of Figure 2 so that there was no direct and unambiguous disclosure in the application as filed of an apparatus of the type as shown by Figure 2 that could make a single image of plural calibration elements. It was also technically not possible for the imaging device of Figure 2 to record an image of several calibration elements. Due to its specific arrangement requiring an optical device and a deflection unit, the imaging device could not see the entire construction field with all the calibration elements. In practice, the field of view of the imaging device changed depending on the position of the electromagnetic radiation. In the representation of Figure 2, the field of view of the imaging device could only detect the calibration element shown on the left-hand side of the bath. In order to detect the calibration element shown on the right-hand side of the bath, another image must be made. It was thus only possible to detect different calibration elements in separate images. But even if this were technically possible, there was no direct and unambiguous disclosure of such a possibility in the application as filed. In this context, it should be noted that the expression "calibration area" on page 42, lines 10 to 16 was not defined. Moreover, the sentence on page 42, lines 32 to 34 of the application as filed did not exclude that the four calibration elements 82a-d were registered by means of different images.

- Reason (ii)

The application as filed did not provide any basis for a single geometric characteristic of a plurality of calibration elements as claimed in features 1.10a and 1.12 of claim 1 of the main request. The geometric characteristic was always mentioned together with a single calibration element, such as on page 4, lines 1 to 6 and page 5, lines 1 to 3 of the application as filed. The passage on page 4, lines 14 to 23 of the application as filed only referred to an image obtained providing information on the geometric position of a single calibration element. Page 6, lines 11 to 15 concerned an embodiment with a plurality of calibration elements without, however, mentioning a geometric characteristic. Assuming that, by definition, a single calibration element had a geometric characteristic (e.g. a length), then, by definition, each calibration element of a plurality of calibration elements should have a geometric characteristic. But this did not mean that a single geometric characteristic was directly and unambiguously disclosed for a plurality of calibration elements. For example, how should one measure the length of a large number of calibration elements? It might be that the geometric position of plural calibration elements would cover information such as the distance between two calibration elements. Such information was contextual but could not be derived without ambiguity from the application as filed. The appellant's interpretation that the distance between the "parallel lines" mentioned on page 5, lines 1 to 3 of the application as filed corresponded to a geometric characteristic of a plurality of calibration elements had no basis whatsoever in the application as filed. Furthermore, the application as filed did not disclose that the solidifying device was controlled based on a geometric characteristic of a plurality of calibration elements. The only disclosure related to the general use of a characteristic for controlling the solidifying device was limited to exactly one calibration element. The passage on page 42, lines 32 to 34 linked plural calibration elements with the registering of geometric information, but claim 1 of the main request was much broader since it did not require the registering of the geometric position.

Auxiliary requests 1 to 7

The requirements of Article 123(2) EPC were not fulfilled for each of auxiliary requests 1 to 7. The arguments provided in respect of the main request apply mutatis mutandis for auxiliary request 1 to 7.

Auxiliary requests 8 and 9

Auxiliary requests 8 and 9 were only submitted during the oral proceedings before the opposition division and were therefore filed late. As correctly stated in points 2.4 and 2.5 of the decision under appeal, auxiliary requests 8 and 9 could not remedy the deficiencies raised under Article 123(2) EPC. On the contrary, they introduced even further deficiencies. Therefore, auxiliary requests 8 and 9 were rightly not admitted by the opposition division and should also not be admitted into the appeal proceedings.

Regarding auxiliary request 8, the wording "an image of each of the plurality of calibration elements" in feature 1.12 of claim 1 did not necessarily mean that plural images were taken, each of which captured a single calibration element. The appellant relied on page 41, lines 4 to 9 of the application as filed as basis for this amendment. However, this passage related to the embodiment shown in Figure 1 in which the camera unit did not register the images via the deflector unit. As such, there was no basis for taking a single image of each of a plurality of calibration elements when the image was registered via the deflector unit. Also the passage on page 5, lines 14 to 15 of the application as filed did not provide basis for the amendment. The appellant's allegation that an interpretation wherein only a single image was obtained by the imaging device was illogical contradicted the same passage on page 41, lines 4 to 9 of the application as filed. There was no indication in the application as filed that this passage should be interpreted as excluding a single image of a plurality of calibration elements. Moreover, the wording "a geometric characteristic of each of the plurality of calibration elements" in feature 1.10a still encompassed the possibility that the solidifying device was controlled based on a single characteristic of the plurality of calibration elements, which was objected to in the context of the main request. Therefore, claim 1 of auxiliary request 8 did not prima facie meet the requirements of Article 123(2) EPC and should not be admitted into the proceedings.

As regards claim 1 of auxiliary request 9, the opposition division correctly concluded that there was no direct and unambiguous disclosure in the application as filed of using a geometric characteristic of each calibration element of the plurality of calibration elements for controlling the position of the electromagnetic radiation during manufacturing of a subsequent layer. Nor was there basis for registering the geometric characteristic of each calibration element of the plurality of calibration elements between the manufacturing of different individual layers of the object. The passage on page 41, lines 5 to 12 of the application as filed relied on by the appellant only referred to using a geometric characteristic of one calibration element for controlling the solidifying device. In addition, the passage was part of the description of the embodiment shown in Figure 1 and was thus not relevant. Hence, there was no disclosure of the amendment to feature 1.10b in the context of an embodiment where the imaging device registered the characteristic via the deflector unit. Also the passage on page 4, lines 19 to 26 of the application as filed only disclosed a control based on a characteristic of a single calibration element. Moreover, it was confined to the manufacture of a single product. In contrast, by virtue of feature 1.10b, claim 1 of auxiliary request 9 covered an embodiment where for example two products were manufactured, wherein the characteristic was registered after a first part of a layer relating to a first product had been solidified, but before solidification of a second part of the layer relating to the second product began. Nor could the amendment be directly and unambiguously derived from page 42, lines 17 to 24 of the application as filed, which related to repeating the step of registering the characteristic directly after the solidifying step. As the opposition division correctly observed, page 6, lines 11 to 15 of the application as filed appeared to be the most relevant passage as regards a plurality of calibration elements. However, it did not describe how such a plurality of calibration elements could increase the accuracy of the calibration. Therefore, auxiliary request 9 should not be admitted into proceedings because it prima facie violated Article 123(2) EPC.