T 0109/00 26-07-2002

1. The appeal is admissible.

2. Amendments - Article 123(2) EPC

2.1. Claim 1 differs from claim 1 as originally filed in that the light source, the sensor means and the light beam from the source to the sensor means reflected by the sealing surface define a plane which is parallel to the rotational axis of the container and at a distance equal to the radius of the sealing surface, i.e. are arranged in a plane tangential with respect to the rotating container surface. This feature is supported by the Figures and the corresponding passage in the original description, see Figure 1 (to be compared with Figure 1 of document D2, where a radial arrangement with respect to the rotation direction is disclosed) and Figure 3, showing such a tangential arrangement including a second pair of light source and sensor means. Furthermore the present claim defines that the incident beam is a collimated beam which is incident at an acute angle onto the sealing surface. This feature finds its support in the embodiment of Figure 1, see page 6, lines 5 to 6.

2.2. Method claim 10 includes the corresponding method features, which are equally supported by the cited passages in the original disclosure.

2.3. Other minor amendments in the dependent claims equally find their support in the application as originally filed.

2.4. Therefore the Board is satisfied that the application documents are in conformity with Article 123(2) EPC.

3. Novelty

3.1. Document D1 shows in the Figures an apparatus for inspecting the finish of a container (glass 3) comprising means (turntable 4) for rotating the container; a light source (5) positioned to direct an incident beam of light at an acute angle (Figures 3 and 9) onto the sealing surface of the container; and light sensor means (1, 2) disposed to receive light reflected by the sealing surface. The light source and light sensor means are disposed above the sealing surface of the container and the incident and reflected beams are in a plane perpendicular to the sealing surface. The apparatus further includes image processing means 12 for detecting variations at the sealing surface of the container. Differing from the requirement in claim 1 of the application in suit, in the apparatus disclosed in document D1 the light from the light source to the light sensor means is in a plane which is not parallel to but coincides with the central rotational axis of the container, therefore this plane is not tangential to the rotation direction of the container surface, but intersects this surface in radial direction, the plane including the centreline of the surface. Furthermore in the apparatus disclosed in document D1 the light source does not emit a narrow collimated beam but either comprises a pair of light sources 5 (Figures 2 and 3) or a single light source emitting a divergent beam (Figures 8 and 9).

3.2. Document D2 discloses an apparatus for inspecting the finish of the sealing surface of a container. As shown in Figures 1 and 2 this apparatus includes means (26) for rotating the container about a rotational axis (23) coinciding with the central axis; a light source (strobe 42) positioned to direct an incident beam of light energy at an acute angle (claim 1) onto the sealing surface (36) of a container (32) in the rotating means; light sensor means (camera 48) disposed to receive light energy reflected by the sealing surface; wherein the light source is positioned to direct the light downwardly onto the sealing surface at an angle to the axis 23 (column 6, lines 8 to 15), whence the light source and the light sensing means define a plane perpendicular to the sealing surface. Furthermore this apparatus includes means (information processor 52 and image memory 54) for detecting variations at the sealing surface of the container (Figure 3).

As is illustrated in Figure 4 of document D2, this plane defined by the light source (illuminated area 58) and the sensor (field of view 48a of camera 48) is orthogonal to the sealing surface, i.e. the plane is arranged in radial direction. Furthermore the illuminated area 58 does not result from a narrow collimated beam, which is also visible from Figure 11. Therefore the features of the characterising portion of claim 1 are not known from this document.

3.3. Document D3 discloses an optical seam position sensor for a welding torch and is not related to an apparatus for inspecting the finish of a container within the definition of claim 1.

3.4. Therefore the subject-matter of claim 1 is novel within the meaning of Article 54 EPC.

For the same reasons the subject matter of claim 10 is considered novel, because this claim defines a method of inspecting the finish of a container with the method features corresponding to the apparatus features of claim 1.

4. Inventive step

4.1. Documents D1 and D2 disclose apparatuses and methods for inspecting the finish of a container with the features of the preamble of claims 1 and 10 of the application in suit. Therefore in addressing the question of inventive step, both disclosures may be considered as a suitable starting point for the problem-solution approach.

4.2. The subject-matter of claim 1 differs from the inspection apparatus according to D1 and the one known from D2 essentially in the arrangement of the light source and the sensor means with respect to the sealing surface of the container under inspection; the choice of the shape of the incident beam; and the data processing of the detected signal. According to the appellant, these differences solve the problem of the detection of the actual height or level of the sealing surface.

4.3. A similar problem, i.e the problem f of controlling the quality of the sealed surface in a container is also addressed in documents D1 and D2. For instance, in document D1, column 8, lines 3 to 13, the detection of uneven or varying height of the lip of the glass surface is discussed. Similarly document D2 discusses in the context of Figure 3A to 3E different exemplary types of unacceptable variations in the sealing surface. Therefore the issue is whether the skilled person, starting from the teaching of either document D1 or D2, would find in the apparatuses disclosed in these prior art documents an incentive to implement the particular solution defined in claim 1.

4.3.1. The inspection apparatus disclosed in document D1, see in particular column 5, line 16, includes a pair of light sensors (CCD cameras) wherein onto each camera the outer portion and inner portion of the lip of a glass surface to be inspected is imaged. By rotating the container and successively photographing the lip at sufficient small pitch the incremental pictures are image-processed to result in two bright lines, which can be compared to detect defects in the container surface. For this particular comparison process both inner and outer portions of the upper surface lip must be illuminated, which in the apparatus according to document D1 is realised by either two light sources (Figure 3) or a single light source with a correspondingly divergent beam (Figure 9). A modification of the light distribution employed in these embodiments by replacing this by a narrow collimated beam would no longer provide the required simultaneous illumination of the inner and outer portions of the lip. Furthermore, in order to sample the inner and outer portions of the lip during rotation of the glass container the CCD camera in the apparatus according to document D1 is arranged orthogonal to the direction of rotation, i.e. in radial direction. If this arrangement were to be modified to a tangential (parallel to the direction of rotation) the idea of comparing the inner and outer portion of the lip would have to be abandoned. Furthermore, since according to document D1 the apparatus already provides information of the uneven or varying height of the container surface, there is no obvious incentive to modify that apparatus in the way as defined in claim 1.

4.3.2. In the inspection apparatus disclosed in document D2 an angular portion of the container surface is imaged onto a linear (Figure 4) or two-dimensional detector (Figure 5) array, the entire container surface being recorded by scanning the detector signals during the rotation of the container around its axis. Also for this process it appears essential that for each scan the angular portion of the surface area is illuminated by the light source, which excludes the use of a narrow collimated beam. Furthermore also in this device the orientation of light source and detector is orthogonal to the direction of rotation of the surface, which at least for the linear detector in Figure 4 appears compulsory. Therefore it is not obvious why the skilled person would modify illumination pattern and the orientation of light source and sensor means in the inspection apparatus disclosed in D2 as defined in claim 1.

4.3.3. During the examination procedure reference had been made to document D3 for showing that the principle of triangulation and lateral effect diodes for determining height differences of a rotating surface was known. According to this document, the surface seam welded by a torch to be inspected is illuminated with a pencil-like beam, which therefore corresponds to a narrow collimated beam.

In the opinion of the board, a combination of the teachings of document D3 with either one of documents D1 or D2 would not a priori appear to be obvious, because the requirements with respect to the illumination schemes of these documents are irreconcilable with the pencil-like beam employed in the system of document D3. Furthermore the arrangement of the triangulation position sensor with respect to the welding torch in the apparatus according to document D3 is concentric in the embodiment of Figure 1 and eccentric in the embodiment of Figure 2, in both embodiments the beam scanning the area in a concentric circular pattern. Therefore this arrangement does not suggest to modify the radial arrangement of light source and sensor means used in documents D1 and D2 to a tangential arrangement as in the apparatus defined in claim 1.

4.4. Therefore claim 1 is neither anticipated nor made obvious by the available prior art. Claims 2 to 9 are dependent on claim 1 and therefore, their subject-matters also involve an inventive step.

For similar reasons the subject-matter of claim 10 is considered patentable, because this claim defines a method of inspecting the finish of a container with the method features corresponding to the apparatus features of claim 1. Claims 11 and 12 are appended to claim 10 and hence equally patentable.

5. For the above reasons, the Board finds that the appellant's request meets the requirements of the EPC and that a patent can be granted on the basis thereof.