T 0927/10 29-01-2014

1. The appeal is admissible.

2. Background of the invention

The invention relates to a glow plug energization control apparatus and method. The aim of the invention is to improve the ease with which a diesel engine can be started by better energization control of a glow plug during starting. In particular the invention aims to energize the glow plug in such a way as to avoid unwanted drops in temperature of the glow plug due to variations in battery voltage or cooling effects such as swirl, see specification, paragraphs [0005] to [0008].

3. Main and first auxiliary requests : added subject matter, Article 123(2) EPC:

3.1 The main and first auxiliary requests add to claim 1 as granted the feature of judging that "an input of a start signal ... is continuously on for a predetermined time".

3.2 The appellant argues that there is a basis for the feature "predetermined time" in paragraph [0077] of the published application in conjunction with figure 5, step S33. The relevant passage in paragraph [0077] states : "Then [after a step S32] the procedure proceeds to step S33, and it is judged whether the input of the start signal is continuously on for 0.1 sec, specifically, whether the input of the start signal is continuously on for eight periods", while step S33 in figure 5 is labelled "whether start signal input is continuously on for 0.1 sec?". Neither expressly disclose the term "predetermined time", rather both disclose a specific time of 0.1 seconds, during which it is continuously judged whether the input of the start signal is continuously on. The feature "predetermined time" therefore represents a generalisation of the specific time period of 0.1 seconds.

Whilst the skilled person might recognise from the stated purpose of continuously checking for a start signal input for 0.1 seconds - namely to exclude noise erroneously generating a start signal (column 17, lines 34 to 37) - that other time periods would also be suitable, he would also understand from second half of the cited passage in paragraph [0077] that the period is not arbitrary but is "specifically" linked to a certain number of clock periods, namely eight such periods. In other words although the skilled person might understand that periods other than 0.1 seconds could be used for reliably generating a start signal, he would not directly and unambiguously derive the feature of any predetermined time period, without the limitation of being a certain number of clock cycle periods. For this reason alone the Board holds that the main and first auxiliary requests add subject matter extending beyond the application as filed.

3.3 Moreover, according to established jurisprudence, see the Case Law of the Boards of Appeal (CLBA), 7th edition, 2010 (herein CLBA), II.E.1.2, and the decisions cited therein, it is normally not admissible under Article 123(2) EPC to extract isolated features from a set of features originally disclosed only in combination in a specific embodiment. An amendment of this nature would only be justified in the absence of any clearly recognisable functional or structural relationship between said features.

3.3.1 In paragraph [0077] of the published application and figure 5, judgement step S33 forms part of a detailed explanation - paragraphs [0071] to [0090] and figures 4 to 10 - of how the energization of the glow plug takes place in the invention.

The effects of this complex energization control are explained in paragraph [0073] of the published application. During the pre-glow step the glow plug resistance heater is rapidly heated to a first target temperature. During the subsequent up-keep and cranking glow steps, a drop in temperature is prevented. Finally during the after starting glow step , the temperature is made a second target temperature which is kept. Thus the energization control is a sequencing and energy control routine for optimising the process of starting a diesel engine.

The various features set out in paragraphs [0073] to [0090] of the published application together define a complex routine made up of many steps giving rise to these effects. None of the steps is given particular prominence, rather the skilled person sees the entire sequence as contributing to the claimed invention's aim of improving engine starting.

The step of judging whether the start signal is continuously on for 0.1 seconds, S33 - which the appellant would have as a basis for the feature "judged...for a predetermined time" as claimed - is thus a single step embedded in a complex routine. Lifting it out of this context by adding it in a generalised form to claim 1 therefore represents a generalisation of the specific routine in which it first appears. Furthermore, it is given a significance over the other features of the routine which is not present in the original disclosure.

3.3.2 The Board acknowledges that in paragraph [0077], continuously checking for 0.1 seconds before deciding that the key switch is in the start position is presented as having the particular effect of avoiding identifying an erroneous start signal due to noise. However, the Board considers that this would not lead the skilled person to conclude that the step S33 has no functional relationship with the remaining features of the entire routine as the appellant has argued. On the contrary, the skilled person would see the feature in the context of reliably being able to pass to the step of setting a start signal flag (step S34) or to take alternative action if the start condition is not met (steps S35 and S36). Setting a start signal flag is, in turn, a small part of the entire glow plug energization routine in which at step S7, see paragraph [0081] of the published application, it is decided whether the start signal flag is set, which if satisfied, allows the routine to pass from step S6, figure 4, paragraph [0080] - calculating an after starting glow duty ratio - to step S8, figure 4, paragraph [0082] - cranking glow processing. Thus the above feature influences how the entire energization routine operates and cannot be seen isolated therefrom.

Even if, as in the first auxiliary request, the (generalised) feature of continuously checking for 0.1 seconds is combined with the further step of setting a start signal flag, step S34, the skilled person still sees these combined steps as part of a complex routine, which is not originally presented in isolation. For example, the combination cannot be isolated from further steps shown in figure 5 and described in paragraph [0077] such as clearing the start signal flag in step S36, or as explained above, decision step S7 of the main routine. Thus the amendments to claim 1 of both the main and first auxiliary request add subject matter not originally disclosed.

3.3.3 Incorporation of isolated features is also not justified by T461/05 as argued by the Appellant. That case concerned the omission of originally claimed features, that were not presented as necessary and had a recognizable function of their own that was independent and thus dissociable from that of the rest of the system, see T461/05 reasons 2.6. In the present case, since the entire glow plug energization routine contributes to improving engine starting as explained above, the skilled person would not see all the remaining features of the specific embodiment, once the step of waiting a predetermined time in order to start the cranking step as claimed has been isolated, as either unnecessary for carrying out the invention or easily dissociable from overall functioning of the routine.

3.3.4 Thus the Board holds that giving the general feature "predetermined time" prominence in the definition of the invention according to the main and first auxiliary requests, that is making it a core feature for achieving the aims of the patent, represents a new teaching which cannot be inferred from the original specific disclosure of the time period 0.1 seconds.

3.4 From the above the Board concludes that both the main and first auxiliary request add subject matter extending beyond the application as filed. The Board concludes that the subject matter of claim 1 according to the main and first auxiliary requests does not meet the requirements of Article 123(2) EPC.

3.5 The Board adds that it arrives at the same conclusion for the independent claim 7 of these requests. Claim 7 sets out the method steps necessarily carried out by the apparatus defined in claim 1. Therefore for the same reasons as given for claim 1, claim 7 likewise does not meet the requirements of Article 123(2) EPC.

4. Second and third auxiliary requests: added subject-matter, Article 123(2) EPC

4.1 The second and third auxiliary requests add to claim 1 , amongst others, the further features that:

- by control of the pre-glow unit, the temperature of the resistance heater is raised up to a first target temperature; and

- by control of the after starting glow unit, the temperature is dropped from the first target temperature

The third auxiliary request then adds the further information that the temperature is dropped from the first target temperature to make the temperature of the resistance heater a second target temperature and to keep this.

4.2 Turning firstly to the third auxiliary request, by specifying a drop in temperature from the first target temperature, claim 1 of this request implies that the (second) target temperature of the resistance heater in the after starting glow phase is lower than the first target temperature in the pre-glow phase. This feature therefore concerns the after starting glow unit, which is generally described in paragraph [0013] of the published application.

The Board is unable to infer from paragraph [0013] any information concerning the relative values of the first and second target temperatures. Paragraph [0013] specifies that the after starting glow unit supplies a lower electric power to the glow plug than is supplied during the pre-glow phase. However, during the pre-glow phase the temperature of the glow plug must be rapidly increased from cold to the first target temperature, paragraph [0010] of the published application - in other words its thermal energy must be rapidly increased - whereas during the after starting glow phase, the second target temperature of the hot glow plug is merely kept stable - that is only energy losses must be compensated. Therefore the relative energy inputs during the two phases gives no information as to the relative values of the first and second target temperatures.

4.2.1 The Board notes that whilst various parts of the published application, see paragraphs [0003], [0073], [0109], [0010] and figure 11, disclose a specific second target temperature (900°C) which is lower than a specific first target temperature (1000°C), the only explicit disclosure of the resistance heater temperature dropping from a first (generic) target temperature to a second (generic) target temperature is in paragraph [0109] of the published application, which forms part of the description of the specific embodiment of the invention. Here it is stated that the temperature of the sheath (resistance) heater is gradually dropped from the first target temperature to a second target temperature and that this is then kept. The appellant argues that this provides a basis for the corresponding feature in claim 1.

4.2.2 The Board disagrees. In paragraph [0109] of the published application, no particular effect is attributed to the drop in temperature from the first target temperature. The technical contribution of the after starting glow unit to the overall aim of reliable starting is generally described in paragraph [0013] of the published application. Amongst others, these are accelerating engine warm-up and preventing diesel knock. All the effects are attributed there to the glow plug being stably heated, that is keeping the temperature stable, without mention of a drop in temperature. This is born out by other parts of the original disclosure, see paragraph [0117] and claims 5 and 12 of the published application.

Therefore, whilst the skilled person would consider it important to keep the second target temperature stable during the after starting glow step, he would attribute neither a particular effect nor any special significance to dropping the temperature of the resistance heater from the first target temperature.

As above, the latter feature is one part of a complex glow plug energization process, described in paragraphs [0092] to [0112] of the published application, with reference to figures 4 to 10. Applying the approach outlined above in point 3.3, the Board holds that lifting the feature out of this specific context and inserting it into the claim therefore represents a generalisation of the specific energization routine and method in which the feature originally appears. Furthermore the extraction raises the feature to prominence, giving it a significance over those other features not included, which it does not have in the original disclosure.

Thus, it is immaterial that the feature per se might have an explicit disclosure in the example embodiment, the skilled person attributes no significance to the drop in temperature of the resistance heater from the first to the second target temperature. The Board has no reason to believe that the skilled person would recognize immediately from this specific disclosure a more general teaching in which dropping temperature to a lower value has some importance or significance in its own right as a desired result which can be abstracted from the specific steps that achieve it. Consequently, including the feature in isolation gives it a prominence in the definition of the invention, that is those features that achieve the aim of the patent as described above, and which is not supported by what the skilled person infers from the original disclosure with regard to this feature.

4.2.3 The Board concludes that adding to claim 1 the feature that the temperature of the resistance heater is dropped from the first target temperature, as claimed, adds subject matter not originally disclosed, contrary to Article 123(2) EPC. Whether or not there is a basis in the original disclosure for the remaining features added to claim 1 is therefore of no further relevance.

4.2.4 The Board adds that it arrives at the same conclusion for independent method claim 6, which sets out the method steps necessarily carried out by the apparatus defined in claim 1. Therefore for the same reasons as given for claim 1, claim 6 does not meet the requirements of Article 123(2) EPC.

4.3 Turning now to the second auxiliary request, the corresponding independent claims 1 and 7 indicate only that temperature drops but not that it drops to a second, kept temperature.

Since the relevant paragraph [0109] of the published application mentions the dropping of temperature of the resistance heater from the first target temperature only in conjunction with the second target temperature, which is kept once it is reached, omission of the second kept temperature represents a generalisation of that specific disclosure, for which there is no basis apparent in the original disclosure. Given that in the original disclosure, keeping the second target temperature is presented as being important during the after starting glow step, see section 4.2.2 above, the skilled person would understand that the feature of dropping from the first target temperature cannot be isolated from a second target temperature which is then kept.

Moreover, temperature drop is portrayed in the original disclosure as part of a complex glow plug energization process, as set out in the previous section. As explained there this step cannot be seen in isolation from the other steps making up that process without adding subject-matter. Consequently, this request also fails for added subject-matter, Article 123(2) EPC.

5. Conclusion

As none of the requests are allowable for added subject-matter, Article 123(2) EPC, the appeal must fail.