T 1179/11 30-06-2016

1. Applicable law

It is noted that the revised version of the Convention (EPC 2000) does not apply to European patent applications pending at the time of its entry into force (13 December 2007), unless otherwise provided. In this decision, where Articles or Rules of the former version of the EPC apply, their citation is followed by the indication "1973".

2. Admissibility of the appeal

The appeal meets the requirements of Articles 106 to 108 EPC and Rule 99 EPC. It is thus admissible.

3. Main request

3.1 Admissibility

The main request was submitted with the grounds of appeal. Therefore, it is in the appeal proceedings (Article 12(1)(a) RPBA).

3.2 Clarity

3.2.1 In the Board's judgement, an essential feature of the claimed transponder is missing in claim 1 of the main request. As recited in claim 1, the second circuit, which is coupled to the antenna assembly, is configured to receive a progression of response signals from said antenna assembly, said response signals having an identifying characteristic. There is, however, no mention in the claim of the fact that the progression of response signals results from transmission of a detection signal progression.

According to a preferred embodiment of the invention, the detection of a transponder in the read range of the transponder detector is performed by evaluating the decay rate of each response signal (cf. published application, paragraph [0075], Figures 6A and 6B). In effect, according to this preferred embodiment, the response signals are constituted by the detection signals themselves possibly distorted because of the electromagnetic coupling resulting from the presence in the read range of the transponder detector of the resonating circuit of a transponder.

While it is acknowledged that the description envisages other techniques for detecting the presence of a transponder in the read range (cf. paragraph [0074]), it does not suggest that the response signals could possibly be generated spontaneously, i.e. independently of any detection signals or in response to signals of a different origin. In other terms, the application as a whole is consistent about the fact that the response signals are signals that result from the generation and transmission by the transponder detector of the detection signal progression (cf. Figure 5, blocks 142, 144). It is further emphasized that it is also not disclosed how the identifying characteristic could be determined in the absence of any causal link between detection signals and response signals.

3.2.2 At the oral proceedings, the appellant did not comment on this issue.

3.2.3 It follows that claim 1 of the main request does not fulfill the requirements of Article 84 EPC 1973.

Therefore, the main request is not allowable.

4. Auxiliary request 1

4.1 Admissibility

4.1.1 Auxiliary Request 1 corresponds to auxiliary request 2 as filed on 6 June 2016 with the letter of reply to the communication of the Board pursuant to Article 15 RPBA.

4.1.2 Under Article 13(1) RPBA, "Any amendment to a party's case after it has filed its grounds of appeal or reply may be admitted and considered at the Board's discretion. The discretion shall be exercised in view of inter alia the complexity of the new subject matter submitted, the current state of the proceedings and the need for procedural economy". It is generally accepted practice that the claimed subject-matter of a late filed request must be so clear and straightforward that it can be easily understood and regarded as solving all the outstanding issues without giving rise to any new objection (cf. Case Law of the Boards of appeal of the EPO, 7th edition 2013, section IV.E.4.4.2, first paragraph).

4.1.3 Claim 1 of auxiliary request 1 differs from claim 1 of the main request in that the feature regarding the second circuit has been specified so as to clarify that it is configured to receive a progression of response signals resulting from transmission of the detection signal progression from said antenna assembly.

The feature that the Board considered to be essential for the definition of the invention and that was missing in claim 1 of the main request is thus explicitly recited in claim 1 of auxiliary request 1.

4.1.4 Moreover, claim 1 does not contain any reference to the "series resistance" or "parallel capacitance", which were objected to by the examining division in its decision to refuse the application.

4.1.5 The Board holds, contrary to the view of the examining division, that the concepts of "first resistance switch", "second resistance switch", "first capacitance switch" and "second capacitance switch" are clear as such. In this respect, it is reminded that the application must be construed by a mind willing to understand, not a mind desirous of misunderstanding (cf. decision T 190/99, not published). In the present context, claim 1 specifies that the first circuit is configured to generate and transmit signals of a high, middle and low frequency. The objected terms relate to switches associated to first and second resistors as well as first and second capacitors of said first circuit. It is well-known to the skilled person that the characteristics of a resonating circuit associated to a given inductance (antenna), i.e. the central resonating frequency and the resonating bandwidth, are defined by the resistors and capacitors it incorporates. The skilled person would thus have recognised that the desired resonance conditions are obtained by an appropriate selection, i.e. by switching, of said circuit elements. The interpretation suggesting that the switches might themselves incorporate resistors or capacitors appears, in this respect, artificial and should therefore be rejected.

4.1.6 The Board thus concludes that it has been remedied to the outstanding clarity objections. Moreover, the amendment introduced in claim 1 is as such clear.

4.1.7 For these reasons, the first auxiliary request is admitted into the proceedings (Article 13(1) RPBA).

4.2 Inventive step

4.2.1 Document D1 discloses a transponder detector which shares a plurality of structural features and a common purpose with the claimed invention. For this reason, document D1 is considered to constitute a realistic starting prior art when deciding on the inventive merits of the subject-matter of claims 1 and 7 of auxiliary request 1.

4.2.2 The transponder detector according to claim 1 essentially differs from the known transponder detector in that the first circuit is configured to generate three detection signals of different frequencies whereas, in D1, the transponder detector generates two frequencies only. In the absence of any details in D1 as to the configuration of the circuits involved, the claimed arrangement further differs from the transponder detector of D1 in that the detection signals generated by the first circuit are obtained by appropriately switching resistors and capacitors in the resonating circuit incorporating the radiating antenna.

The claimed arrangement, with its multiple switchable resistors and capacitors, permits communication with a larger variety of transponders, in particular with transponders operating in at least three different frequency bands. In the absence in claim 1 of any indication as to which resistor(s) or capacitor(s) should be switched, the sole effect which can be recognised would consist in that the Q-factor of the resonating circuit can be varied.

4.2.3 The problem of communicating with transponders resonating at various resonating frequencies is explicitly addressed in document D2 (cf. page 3, lines 2-14). In D2, a plurality of capacitors is foreseen, each of which is added, alone or in combination with other capacitors, in parallel to a main tuning capacitor, as it is the case for the present invention (cf. page 10, lines 1-11; Figure 4), so as to generate a sequence of detection signals of various resonating frequencies.

While document D2 privileges a solution including a multiplicity of resonating frequencies in order to maintain high sensitivity of the transponder detector, it nevertheless does not exclude the possibility to use low-Q antenna circuits in the detector (cf. page 4, lines 3-12; page 5, lines 1-3; page 14, lines 3-14). In the Board's judgement, this indication would constitute a clear hint for the skilled person to incorporate one or more resistances in the antenna circuit disclosed in document D1 so as to affect the Q-factor of the resonating circuit.

As put forward by the appellant, it is acknowledged that said Q-factor may also be affected by modifying the inductance. However, the Board holds that this option, should it not be excluded, would have not been privileged. A change of the inductance would indeed imply a shift of the resonating frequency only to be avoided by simultaneously modifying the capacitance of the resonating circuit so that the product of inductance by capacitance be kept constant. Moreover, a change of inductance would be detrimental to a good functioning of the antenna since it would directly affect the magnetic field it generates and, as a consequence, its read range.

For these reasons, the skilled person would have undoubtedly selected a solution with switchable resistors which would neither affect the resonating frequency of the circuit nor the emitting characteristics of the antenna.

4.2.4 The subject-matter of claim 1 of auxiliary request 1, therefore, results in an obvious manner from a combination of documents D1 and D2 and is thus not inventive in the sense of article 56 EPC 1973.

As a consequence, auxiliary request 1 is not allowable.

5. Auxiliary request 2

5.1 Admissibility

5.1.1 Auxiliary request 2 was filed during the oral proceedings before the Board following the announcement by the Chairman that auxiliary request 1 does not meet the requirements of article 56 EPC 1973.

5.1.2 When exercising its discretion under Article 13(1) RPBA, the Board considered whether the amendments carried out affected the finding of lack of inventive step reached with regard to claim 1 of auxiliary request 1.

5.1.3 Firstly, the feature of a ping output signal source does not appear to define any additional difference between the claimed subject-matter of claim 1 and document D1, since D1 refers in paragraph [0027] explicitly to the emission of "ring signals" as disclosed, inter alia, in document US-A-6 476 708, i.e. the same document as the one referred to by reference in the present application when referring to the emission of the detection signals.

Secondly, the presence of the resistors and capacitors of the circuit between the excitation source (ping output signal source) and the antenna, appears to reflect one possibility among equally likely alternatives. It is stressed in this respect that the resonating characteristics of the circuit are, in particular, defined by the values of the resistance(s), capacitance(s) and inductance(s) as resulting from the presence in the serial circuit of the corresponding circuit elements.

Thirdly, the indication according to which the first circuit is configured to generate the low or middle frequency detection signal by selectively increasing the capacitance(s) and resistance(s) in the circuit path of the ping signal does also not appear to be sufficient to justify an inventive step. While it is acknowledged that the claimed feature implies that the bandwidth of the resonating circuit is larger for smaller frequencies than that for higher frequencies, the appellant did not indicate which advantages resulted therefrom. The Board is thus unable to identify any specific problem solved by the claimed arrangement on the basis of which the presence of an inventive step could have been assessed.

5.1.4 For these reasons, claim 1 of auxiliary request 2 does not appear to affect the finding regarding the lack of an inventive step reached by the Board with regard to claim 1 of auxiliary request 1.

Auxiliary request 2 is therefore not admitted into the proceedings.

6. Auxiliary request 3

6.1 Admissibility

6.1.1 Auxiliary request 3 corresponds to auxiliary request 4 as filed on 6 June 2016 with the letter of reply to the communication of the Board.

6.1.2 Claim 1 of auxiliary request 3 includes the amendment concerning "an inverter (82) connected between the first switched parallel capacitor (74) and the first series resistance (64) to shape the generated and transmitted signal temporally and in amplitude".

The claimed feature defines an unallowable generalisation of a specific embodiment of the invention, as disclosed with regard to Figure 4 and paragraph [0053] of the published application, contrary to Article 123(2) EPC. According to said embodiment of the invention, an inverter is connected between the series resistances 62, 64, 68 and the parallel capacitances 72, 74, 78. The claimed wording now covers various alternatives as, for example, a configuration with an inverter between the switched series resistance (64) and resistance 62 or between capacitance 72 and switched capacitance 74. There is no indication to be found in the description suggesting that the specific configuration of Figure 4 could be modified without affecting the functionality of the resonating circuit.

6.1.3 The appellant did not comment on the objection raised by the Board.

6.1.4 Therefore, auxiliary request 3 is not admitted into the appeal proceedings (Article 13(1) RPBA).

7. Auxiliary request 4

7.1 Admissibility

7.1.1 Auxiliary request 4 was filed during the oral proceedings before the Board.

7.1.2 Claim 1 of auxiliary request 4 differs from claim 1 of auxiliary request 1 in that it has been specified that "the controller (22, 44) is further configured to evaluate a power level of the received progression of response signals and to assert a protection mechanism to protect the second circuit(42) from the incoming energy when an unsafe threshold level is exceeded".

The added features derive directly and unambiguously from Figure 4 and paragraphs [0085] to [0087] of the published application.

7.1.3 The claims of auxiliary request 4 overcome all outstanding objections without giving rise to any new objection. In particular, the Board is satisfied that claim 1 meets the requirements of Article 84 EPC 1973, Article 123(2) EPC and Article 83 EPC 1973.

7.1.4 Therefore, auxiliary request 4 is admitted into the appeal proceedings (Article 13(1) RPBA).

7.2 Decision in respect of the appeal

7.2.1 The new features in independent claims 1 and 10 of auxiliary request 4 are not disclosed in any of the documents presently available. The added features permit to identify any surge of energy potentially dangerous to the second circuit and to react accordingly. The analysis relied upon by the Board to justify the objection of lack of an inventive step of the subject-matter of claim 1 of auxiliary request 1 therefore does not apply to claims 1 and 10 of auxiliary request 4.

7.2.2 Moreover, it is underlined that said new features derive from the description. For this reason, the Board holds that it would be expedient to remit the case to the examining division for further prosecution (Article 111(1) EPC). During the oral proceedings, the appellant agreed to the remittal of the case.