PCT International Search and Preliminary Examination Guidelines
PART III EXAMINER CONSIDERATIONS COMMON TO BOTH THE INTERNATIONAL SEARCHING AUTHORITY AND THE INTERNATIONAL PRELIMINARY EXAMINING AUTHORITY
Chapter 13 Inventive step
13.14 The following examples provide guidance, as to circumstances where a claimed invention should be regarded as obvious or where it involves a positive determination of an inventive step (non-obviousness). It is to be stressed that these examples are only guides for the examiners and that the applicable principle in each case is "was it obvious to a person skilled in the art?" Examiners should avoid attempts to fit a particular case into one of these examples where the latter is not clearly applicable. Also the list is not exhaustive.
(a) Claimed inventions involving the application of known measures in an obvious way and in respect of which an inventive step is therefore lacking:
(i) The teaching of a prior document is incomplete as to the entire claimed invention and at least one of the possible ways of supplying the missing claim feature(s) would naturally or readily occur to the person skilled in the art thereby resulting in the claimed invention.
Example: The claimed invention relates to a building structure made from aluminum. A prior document discloses the same structure and says that it is of lightweight material but fails to mention the use of aluminum. Aluminum is a light-weight material that is well known in the art to be useful as a building material.
(ii) The claimed invention differs from the prior art merely in the use of well-known equivalents (mechanical, electrical or chemical) possessing the same purpose, wherein the equivalency is recognized in the prior art. Note that the applicant's recognition within the international application that an element is equivalent to another, which had previously been used for a different purpose, does not mean that the use of this element instead of the other is obvious.
Example: The claimed invention relates to a pump-motor combination which differs from a known pump-motor combination solely in that the motor is hydraulic instead of an electric motor.
(iii) The claimed invention consists merely in a new use of a well-known material employing the known properties of that material.
Example: A washing composition containing as a detergent a known compound having the known property of lowering the surface tension of water, this property being known to be an essential one for detergents.
(iv) The claimed invention consists in the substitution in a known device of a recently developed material whose properties make it plainly suitable for that use (analogous substitution).
Example: An electric cable comprises a polyethylene sheath bonded to a metallic shield by an adhesive. The claimed invention lies in the use of a particularly newly developed adhesive known to be suitable for polymer-metal bonding.
(v) The claimed invention consists merely in the use of a known technique in a closely analogous situation (analogous use).
Example: The claimed invention resides in the application of a pulse control technique to the electric motor driving the auxiliary mechanisms of an industrial truck, such as a fork-lift truck, the use of this technique to control the electric propulsion motor of the truck being already known.
(b) Claimed inventions involving the application of known measures in a non-obvious way and in respect of which an inventive step is therefore present:
(i) A known working method or means when used for a different purpose involves a new, surprising effect.
Example: It is known that high-frequency power can be used in inductive butt welding. It should therefore be obvious that high-frequency power could also be used in conductive butt welding with similar effect. An inventive step would exist in this case, however, if high-frequency power were used for the continuous conductive butt welding of a coiled strip but without removing scale (such scale removal being ordinarily necessary in order to avoid arcing between the welding contact and the strip). The unexpected result is that scale removal is found to be unnecessary because at high frequency the current is supplied in a predominantly capacitive manner via the scale which forms a dielectric.
(ii) A new use of a known device or material involves overcoming technical difficulties not resolvable by routine techniques providing that the means for overcoming the technical difficulties are defined in the claim.
Example: The claimed invention relates to a device for supporting and controlling the rise and fall of gas holders, enabling the previously employed external guiding framework to be dispensed with. A similar device was known for supporting floating docks or pontoons but practical difficulties not encountered in the known applications needed to be overcome in applying the device to a gas holder.
(c) Obvious combination of features not involving an inventive step:
The claimed invention consists merely in the juxtaposition or association of known devices or processes functioning in their normal way and not producing any non-obvious working interrelationship.
Example: Machine for producing sausages consists of a known mincing machine and a known filling machine disposed end to end.
(d) Not obvious and consequently a combination of features involving an inventive step:
The combined features mutually support each other in their effects to such an extent that a new technical result is achieved. It is irrelevant whether each individual feature is fully or partly known by itself.
Example: A mixture of medicines consists of a painkiller (analgesic) and a tranquilizer (sedative). It was found that through the addition of the tranquilizer, which intrinsically appeared to have no pain-killing effect, the analgesic effect of the pain-killer was intensified in a way which could not have been predicted from the known properties of the active substances.
(e) Obvious selection or choice among a number of known possibilities not involving an inventive step:
(i) The claimed invention consists merely in choosing from a number of equally likely alternatives.
Example: The claimed invention relates to a known chemical process in which it is known to supply heat electrically to the reaction mixture. There are a number of well-known alternative ways of so supplying the heat; the claimed invention resides merely in the choice of one alternative way of supplying the desired heat.
(ii) The claimed invention resides in the choice of particular dimensions, concentrations, temperature ranges or other parameters from a limited range of possibilities, and it is clear that these parameters or workable ranges were encompassed by the prior art and could be arrived at by routine trial and error or by the application of normal design procedures. Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.
Example: The claimed invention relates to a process for carrying out a known reaction and is characterized by a specified rate of flow of an inert gas. The prescribed rates are merely those which would necessarily be arrived at by a person skilled in the art.
(iii) The claimed invention can be arrived at merely by a simple extrapolation in a straightforward way from the known art.
Example: The claimed invention is characterized by the use of a specified minimum content of a substance X in a preparation Y in order to improve its thermal stability, and this characterizing feature can be derived merely by extrapolation on a straight-line graph, obtainable from the known art, relating thermal stability to the content of substance X.
(iv) The claimed invention consists merely in selecting a small number of chemical compounds (that is, a subgenus or species) from a broad field of chemical compounds (genus).
Example: The prior art discloses a chemical compound characterized by a generic formula including a substituent group designated "R." This substituent "R" is defined so as to embrace entire ranges of broadly defined radical groups such as all alkyl or aryl groups either unsubstituted or substituted by halogen and/or hydroxy. Only a very small number of examples of specific embodiments within the broadly defined radical groups are disclosed in the prior art. The claimed invention consists in the selection of a particular radical or small group of radicals from among those well-known to be contained within the broadly defined radical groups disclosed in the prior art as the substituent "R". The prior art provides motivation to select any well-known member of the broadly defined radical groups and thus, provides motivation to one skilled in the art to make the modifications needed to arrive at the claimed compound(s). Moreover, the resulting compounds:
- are not described as having, nor shown to possess, any advantageous properties not possessed by the prior art examples; or
- are described as possessing advantageous properties, compared with the compounds specifically referred to in the prior art but these properties are ones which the person skilled in the art would expect such compounds to possess so that he is likely to be led to make this selection.
(f) Non-obvious selection or choice and consequently inventive step among a number of known possibilities:
(i) The claimed invention involves the special selection within a process of particular operating conditions (for example, temperature and pressure) within a known range, such selection producing unexpected effects in the operation of the process or the properties of the resulting product.
Example: In a process where substance A and substance B are transformed at high temperature into substance C, it was known in the prior art that there is in general a constantly increased yield of substance C as the temperature increases in the range between 50 and 130°C. It is now found that in the temperature range from 63 to 65°C, which previously had not been explored, the yield of substance C was considerably higher than expected.
(ii) The claimed invention consists in selecting particular chemical compounds (subgenus or species) from a broad field of compounds (genus), wherein the specific compounds selected have unexpected advantages.
Example: In the example of a substituted chemical compound given at (iv) under (e), above, the claimed invention again resides in the selection of the substituent radical "R" from the total field of possibilities defined in the prior art. In this case, however, not only does the invention embrace the selection of specific compounds from the possible generic field of compounds and result in compounds that are described and shown to possess advantageous properties, but there are no indications which would lead the person skilled in the art to this particular selection rather than any other in order to achieve the described advantageous properties.
(g) Overcoming a technical prejudice:
As a general rule, there is an inventive step if the prior art leads the person skilled in the art away from the procedure proposed by the claimed invention. This applies in particular when the person skilled in the art would not even consider carrying out experiments to determine whether these were alternatives to the known way of overcoming a real or imagined technical obstacle.
Example: Drinks containing carbon dioxide are, after being sterilized, bottled while hot in sterilized bottles. The general opinion is that immediately after withdrawal of the bottle from the filling device, the bottled drink must be automatically shielded from the outside air so as to prevent the bottled drink from spurting out. A process involving the same steps but in which no precautions are taken to shield the drink from the outside air (because none are in fact necessary) could therefore involve an inventive step.