Tag Archives: patent search

Best Practices for Conducting a Patent Invalidation Search


Patent invalidation/validation searches are performed to assess the validity of a granted patent. In general, an invalidation search is sought by companies sued for infringing a granted patent claim(s), and a validation search is sought by an entity/individual before suing an infringer to assess the patent’s validity. The procedure followed for preforming both these searches is identical to a large extent. However, the terminology and preferences may vary depending whether the search is sought by a patent holder or an alleged infringer. Additionally, invalidation/validation searches may also be considered before seeking license for a patent, and in evaluating the strength and value of patent portfolio during mergers and acquisitions.

Establishing priority date:

Before performing an invalidation search, one has to first establish the priority date of the claims in the patent which needs to be invalidated. In general, any disclosure that is available to the public before the date of filing of the patent to be invalidated is considered prior art. Also, even if a patent application is published after the filing date of the patent to be invalidated, but the published patent applications filing date is before the filing date of the patent in question, then the published patent application is considered to be a prior art.

That being said, there will be scenarios where the patent to be invalidated is a continuation patent or a continuation-in-part patent (referred to as patent of addition in some countries), which can claim priority from one or more patent applications. In such scenarios, it may be difficult to identify the exact priority date since the patent is claiming priority from multiple applications. A searcher has to analyze the claims of the patent to be invalidated to determine the first patent application in the entire family, which discloses all the limitations in the claims (at least the independent claim) of the patent to be invalidated. In most of the cases, majority of the features may be disclosed in the previously filed patent applications, however there may be features which are be disclosed only in the patent to be invalidated. In case such features/limitations are part of the claims of the patent in question, then it can be argued that the priority date for such claims should be the filing date of the patent to be invalidated.   

In case a searcher faces any difficulty in identifying the priority date, it may be better to discuss the same with the attorney and the client. However, as a rule of thumb, it’s always advisable to consider the filing date of the patent in performing an invalidation search, as an attorney can take the final decision and filter the references at a later stage, if required.

Additionally, in case a reference found to invalidate the patent is a PCT (Patent Co-operation Treaty) application or a national phase application claiming priority from different applications, a searcher should keep in mind that the effective date calculation for the reference may vary based on the jurisdiction of the patent to be invalidated. For example, in certain scenarios, as per US laws, a U.S. patent application publication of a National Stage application and a WIPO (World Intellectual Property Organization) publication of an international application are considered to be prior art as of the international filing date only if the international application was filed on or after November 29, 2000 designating the United States and was published in English.

Sources and strategies:

Once the priority date is established for the patent to be invalidated, the searchers next goal is to find references (non-patent literature or patent literature) which are available before the established priority date and disclose the claimed limitations of the patent in question. Essentially, the main objective will be to find a single reference disclosing all the claimed limitations; however it may not always be possible.

A searcher in analyzing the claimed features must adopt broadest reasonable interpretation, and may also refer to the file history of the patent in order to identify the novel aspects of the claims. Such analysis may also provide an insight into keywords, key strings, and classification used by the examiner, references cited by examiner and applicant, arguments of both parties, and reasons for allowing claims, among others. Further, the searcher may have a clear idea about the aspects of the claims which are critical, and can lay out strategies for finding references teaching such aspects. In some cases, analyzing the references cited by the examiner and there family members can be helpful, as it’s always possible that the examiner may have missed out on few key excerpts which may help in invalidating the patent.

Paid patent databases usually enable identification of superior results as compared to free databases for various reasons such as, wide data coverage, abundant options to query the database, flexible search interface, and various additional features like similar patent search and citation analysis, among others. However, one may also consider free databases as they may also provide good results at times. Searchers should also focus on Non-Patent Literature (NPL) as not all examiners rely on them during prosecution. NPL includes any public document or disclosure other than patent literature. One common problem faced with NPL’s is in determining the date they are made available to public, for example, disclosure on websites may sometime not include date on which it is made available. In such scenarios, searchers can utilize web archive resources like “waybackmachine.org” to check whether the disclosure is available before the established priority date.

Searcher should also keep in mind that every search is different and a single protocol for all searches does not exist. The keywords, key strings, classifications and search strategies used for a search should evolve with time based on the search results found.

To know more about general prior art search strategies click here

I hope you found this article helpful. You may also download a copy for your reference. 

You may subscribe to our articles to receive notification of such interesting articles in your inbox.

Feel free to check our patent services page to find out, if we can cater to your requirements.

Best regards – Team InvnTree   

This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License


Using Patent Citations as an Effective Tool While Conducting Prior Art Search


A prior art search is conducted for several reasons. Some of the reasons may include assessment of novelty, invalidation of patents, competitor and technology monitoring, and patent landscape study among others. A prior art search may be carried by using a combination of various techniques. Typically, techniques for carrying out prior art search include key-words strings, patent classifications, inventor based searching, assignee based searching and citation based searching.

Among the techniques of searching, citation based searching is frequently ignored, although citation based searching can deliver extraordinary results. 

Patent citations

A patent citation is an instance where a patent or an application mentions or includes a reference to an earlier patent or patent application. Its function is similar to an academic paper citation which cites an earlier published work. Patent citations may be added by the patent examiner as well as the applicants of the patent.

Generally, patent citations included by the examiner are for the purpose of restricting patent claims, while those included by the inventor/applicant are for demonstrating prior art related to the invention. In either case, prior art patent citations are used to assess patentability of an alleged invention.

A patent/application, which may be referred to as a root document, may primarily have two types of patent citations, viz., backward citations and forward citations. Backward citations of a root document are patents/applications that are referred by the root document. Forward citations of a root document are patent/application referring to the root document. Any of the backward and forward citations may be a self-citation. Self-citation is when the root document cites or be cited by a patent/application that mentions the same author or assignee as the root document.

Finding patent citations

Backward citations of a root document may be found in the root document itself under a heading of “References cited” or similar headings. Forward citations may be found in online patent databases. One should note that the list of forward citations, unlike backward citations, may grow over time. The European Patent Office database is a freely available resource where both forward and backward citations can be found. Most other free databases only make backward citations available. Most of the paid private patent databases make both the citations available, since these databases use INPADOC, which is a database created and maintained by the European Patent Office. 

Reasons for using patent citation based search

There are several reasons why patent citation based searching technique has to be part of the overall prior art search strategy, and some of the reasons are discussed below.  

Tapping into ready-to-use human curated relevant search results

Patent citations are a result of one or more (in case of forward citations) examiners' efforts to identify relevant prior art references while conducting examination. The examiner cites a prior art reference after having reviewed the reference in detail, and not just because the prior art reference has a few key words that appear to be relevant. Hence, human intelligence would have been applied in citing a reference as relevant. It would be wise to use the set of documents grouped together by way of citations in prior art searching. Once a patent/application has been identified as relevant, its citations may disclose aspects related to the root document, which may also be relevant to the prior art search. 

Improving the ability to structure claims and description better

One of the key challenges in claims drafting is defining the spread of prior art. A set of citations, when considered together, can help in defining the spread of prior art teaching in the context of a proposed invention. Such a contextual understanding of prior art can help in defining the scope of the claims in a way that the claims are neither too broad, thereby resulting in the prior art rendering the claims un-patentable, nor too narrow, thereby failing to exploit the full potential of the invention. 

Identify a technological trend

Patent citations are one of the best sources to track the flow of innovation in a particular field of technology. With the help of backward and forward citations, it is possible to map knowledge spill-overs from earlier inventors to later inventors. Additionally, citations help in recognizing trends in technology and innovation which may be useful in determining potential research fields. It is also possible to identify seminal patents by analysing patent citations, among other factors. A seminal patent covers an invention which is considered to be so important that it creates a technological shift in a particular field of technology. A patent having a relatively large number of forward citations when compared to other patents in its field may be a seminal patent. 

Assessing patent’s commercial value

A variety of situations may require a market value to be estimated for patents. As an example, patent valuation may be required when a patent owner is looking for investors or manufacturers, in case of company takeovers, or during the buying/licensing of patents. In such situations, analysis of patent citations may help towards assessing commercial value of patents. It is generally accepted that a patent having numerous forward citations may turn out to be more valuable when compared to patents with fewer forward citations. This is because, having many forward citations means that the technology disclosed by the patent was used by many other inventors in subsequent developmental efforts, resulting in various new innovations that have their roots in this patent, thereby increasing the value of the patent.

Mitigating infringement risks  

Freedom to operate studies are conducted to identify patents that might have the potential of being infringed by a product/process. In case patents that may adversely impact the freedom to operate are identified, then it would be wise to also consider citations of such patents in the freedom to operate study. Since citations mostly disclose information that may be closely related to the root patent, there is a likelihood that claims of such citations may also be relevant in assessing freedom to operate.


Effectiveness of prior art search has far reaching implications. Hence, attempts are made to make prior art search as robust as possible by using various search strategies. Among the search strategies, classification based searching and key-words strings based searching will in most scenarios be the primary search strategies. Once a bunch of relevant references are identified by using these primary strategies, citation based searching using the identified relevant references will exponentially improve the quality of the prior art search exercise. Hence, although citation based searching can most often be a secondary search strategy, its impact should not be neglected and citation based searching should always be part of prior art search exercise.

I hope you found this article helpful. You may also download a copy for your reference. 

You may subscribe to our articles to receive notification of such interesting articles in your inbox.

Feel free to check our patent services page to find out, if we can cater to your requirements.

Best regards – Team InvnTree   

This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License

How can I find out whether my invention is patentable?

In order for a proposed invention to be awarded a patent, it has to pass the following five tollgates:
  • Patentable subject matter
  • Novelty
  • Non-obviousness/inventive-step
  • Industrial application
  • Enablement 
Patentable subject matter
The proposed invention which seeks a patent should fall outside the scope of “non-patentable subject matter”. Almost every country provides a list of subject matter, which cannot be patented.
In India, section 3 and 4 of Indian Patent Act (Law governing patent system in India) , discloses such non-patentable subject matters. For example, in India, non-patentable subject matter include, laws of nature or anything opposing them, physical phenomenon, abstract ideas, discovery of any living thing or non living substance, method of agriculture or horticulture, new form of know substances, method of playing games, any aesthetic creations, anything that causes a serious harm to human, animal, plant life or to the environment, among others.
Once a proposed invention passes this tollgate, the patent office will look into the novelty aspect.
The proposed invention will be announced as novel, if it has not been anticipated by information available in public domain prior to the priority date (first filling date) of a patent application for the proposed invention. Proposed invention passing this tollgate will be further scrutinized to check compliance with non-obviousness requirement of patentability.
The invention can pass the non-obviousness tollgate, if it has technical advancement with respect to know prior art (existing public knowledge). This technical advancement should not seem obvious to a person skilled in the field of the proposed invention, in light of prior art. Most of the proposed inventions find it difficult to pass this tollgate, as the interpretation of law governing this requirement is subjective in nature.
Industrial application
The next tollgate in obtaining a patent is industrial application. Industrial application according to the Indian Patent Act means, the proposed invention should be capable of being made or used in the industry. Most proposed inventions satisfy this requirement, unless the proposed invention is frivolous in nature.
Enablement requirement can be met as long as the inventors have sufficient information to reduce the proposed invention to practice. Information that enables the proposed invention to be reduced to practice should be included in the patent application corresponding to the proposed invention. The Indian Patent Act requires the patent application to include information that enables a person with ordinary skill to practice the invention. The Patent Act also requires the patent applicants to disclose the best approach of practicing the invention, which is known to them at the time of filing the application.
I hope you found this article helpful. You may also be interested in reading our other related articles:
Please feel free check our patent services page to find out if we cater to your patent requirements.
You can download a copy of this article here
Best regards,
Team InvnTree   

Determination of Obviousness/Inventive Step by the European Patent Office


Basic Patentability requirements are

  • NOVELTY/NEW – Not previously known by others or previously available in the  public domain
  • USEFUL-  Must have practical utility to accomplish an useful purpose
  • NONOBVIOUSNESS / INVENTIVE STEP-The invention must not be obvious to one of ordinary skill in the art.
The Inventive step and Non-obviousness implies the same meaning in most patent laws. The expression “Inventive step” is used in Europe while “Non-Obviousness” is used in United States.
Need for Inventive step 
Inventive step is a critical element in patentability. To obtain a patent, the patent system expects something more than merely novel subject matter. The European Patent Convention (EPC) states that, an invention must be new and must involve an inventive step. One of the main reasons is that, it is relatively easy to make something which is merely new, for example by adding minor workshop modification to something that is already known. The requirement of inventiveness or non-obviousness has thus been developed over time so as to exclude from patentability, minor matters that are considered obvious.
Evaluating Inventive step 
As per Art 56 of EPC "an invention shall be considered as involving an inventive step if, having regard to the state of the art, it is not obvious to a person skilled in the art".
  • State of the art: "everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of the filing of the European patent application"
  • Person skilled in the art: “should be presumed to be a skilled practitioner in the relevant field of technology, who possesses average knowledge and ability, and is aware of what was common general knowledge in the art at the relevant date ".
The boards of Appeal of the European Patent office (EPO) have developed an approach, called the "Problem-Solution approach”. This problem solution approach is applied by the examining division, the opposition divisions and the boards of Appeal of the EPO to decide whether an invention involves inventive step. The EPO considers it essential for reason of legal certainty to devise a legal test which could be applied in all situations and which goes beyond simply asking "is it obvious to a person skilled in the art?” 
Problem-Solution Approach 
The problem-solution approach essentially consists three steps:
  •        Selecting the closest prior art
  •        Formulating the technical problem
  •        Assessing the obviousness of the claimed solution
Selecting the closest Prior art 
When selecting the closest prior art, the first consideration is that, it should be directed to a similar purpose or effect as the invention, or at least belong to the same or a closely related technical field. It is important to remember that, the document, which is most relevant for assessing novelty, is not necessarily the most promising starting point for assessing inventive step. 
In general, the closest prior art corresponds to a similar use as the claimed invention and requires the minimum of structural and functional modifications to arrive at it. The closest prior art must be assessed from the point of view of the skilled person on the day before the filing date or priority date of the claimed invention. 
Assessing the technical difference 
In the second stage of the problem-solution approach starts with the question “what is the difference, in terms of the technical features, between the claim and the closest prior art?" This question arises only when novelty of the invention is satisfied.
The difference between the closest prior art and the claimed invention helps in determining the presence of an invention step. This difference is formulated in terms of features, such as:
  • additional features
  • modified features
  • functional features
Example: The claimed invention is directed to a table having a flat surface supported by four legs, one of them being telescopic, i.e. retractable or extendable thus having an adjustable length. The inventor argues that the claimed invention solves the problem of wobbling tables. The closest prior art is a normal table having four legs of fixed length.In terms of the technical features, the technical difference between the claim on the one hand and the closest prior art on the other is that, one leg of the table is telescopic. 
The second question in the second stage is determining the technical effect caused by the difference, which defines the objective technical problem.  
The technical effect is the result of the difference achieved by features which distinguish the claimed invention over the closest prior art. The features which contribute to the technical character of the invention should be considered. 
One starting point for the assessment of the technical effect can be the analysis of what the applicant states in the description to be the effect of his /her invention. However, one might have a closest prior art different from the starting point of the applicant, the technical effect might be correspondingly different. It may also be that both the claimed invention and the closest prior art achieve the same technical effect, only in different ways.  
Considering the same example mentioned above, in which the technical effect caused by this difference is that the table can be placed on an uneven surface without wobbling. 
The last question in the second stage is, examining the objective technical problem underlying in the claimed invention. In terms of the problem-solution approach, the "objective technical problem" comprises the reason for and the task of modifying or adapting the closest prior art to provide the technical effects that the invention provides over the closest prior art. The objective technical problem is based on objectively established facts, in particular those appearing in the prior art revealed in the course of the proceedings. 
A particular difficulty in assessing inventive step arises when the distinguishing features (the difference) and the corresponding result achieved (technical effect) are already known.
Considering the example, the objective technical problem underlying the claimed invention is how to modify the table known from the closest prior art so that it does not wobble when placed on the uneven surface. In this case, the problem proposed by the applicant is considered to be the objective technical problem. 
In the third stage of the problem-solution approach, it is determined whether there is any teaching in the prior art as a whole that not only could, but would have prompted the skilled person, faced with the objective technical problem, to modify or adapt the closest prior art while taking account of that teaching, thereby arriving at something falling within terms of the claims, and thus achieving what the invention achieves. 
With reference to the example, the closest prior art is a normal table having four legs of fixed length. The technical difference, in terms of the technical features, between the claim on the one hand and the closest prior art on the other is that, one leg of the table is telescopic. The technical effect caused by this difference is that the table can be placed on an uneven surface without wobbling. The objective technical problem underlying the claimed invention is how to modify the table known from the closest prior art so that it does not wobble when placed on an uneven surface. 
A second prior art document discloses a milk stool having three legs as used by milkers in cow sheds or in the field. The document acknowledges that the three-legged construction provide stability to these stools, which are normally used on uneven surfaces. 
The invention is not obvious, since the person skilled in the art of furniture would not find in this second document any indication to arrive at the claimed subject-matter when starting from the closest prior art and confronted with the objective technical problem. Although the second document is confronted with the same problem, the combination of the two documents would lead to a table having three legs. These tables would be stable on an uneven surface, thus solving the problem in an alternative way. No hint is given to providing a telescopic leg. It is therefore concluded that the claimed invention is not obvious and is therefore inventive. 
Combining pieces of prior art 
During the problem-solution approach, a situation occurs where the invention is a solution to a plurality of independent "partial problems”. In such a case, it is necessary to separately assess, for each partial problem, whether the combination of features solving the partial problem is obviously derivable from the prior art. Hence, a different document can be combined with the closest prior art for each partial problem. For the subject-matter of the claim to be inventive, it suffices however that one of these combinations of features involves an inventive step.
In determining whether it would be obvious to combine two or more distinct disclosures, the examiner should also have regard in particular to the following:
  • whether the content of the disclosures (e.g. documents) is such as to make it likely or unlikely that the person skilled in the art, when faced with the problem solved by the invention, would combine them – for example, if two disclosures considered as a whole could not in practice be readily combined because of inherent incompatibility in disclosed features essential to the invention, the combining of these disclosures should not normally be regarded as obvious;
  •  whether the disclosures, e.g. documents, come from similar, neighbouring or remote technical fields;
  • the combining of two or more parts of the same disclosure would be obvious if there is a reasonable basis for the skilled person to associate these parts with one another. It would normally be obvious to combine with a prior-art document a well-known textbook or standard dictionary; this is only a special case of the general proposition that it is obvious to combine the teaching of one or more documents with the common general knowledge in the art. It would, generally speaking, also be obvious to combine two documents one of which contains a clear and unmistakable reference to the other. In determining whether it is permissible to combine a document with an item of prior art made public in some other way, e.g. by use, similar considerations apply.
Combination vs. juxtaposition or aggregation 
An invention claimed is considered as a whole. When a claim consists of a "combination of features", it is not correct to argue that the separate features of the combination taken by them are known as obvious and therefore the whole subject-matter claimed is obvious.
However, the invention claimed is merely an aggregation or juxtaposition of features and not a true combination; it is enough to show that the individual features are obvious to prove that the aggregation of features does not involve an inventive step. A set of technical features is regarded as a combination of features if the functional interaction between the features achieves a combined technical effect which is different from, e.g. greater than, the sum of the technical effects of the individual features. 
Case study for the claimed invention vs the prior art Document for the lack of Inventive step  
According to the art 100(a) and (b) the opposition for the granted patent can be raised on the grounds of the invention claimed in the complete specification does not involve inventive step. This was well established in the case TeliaSonera Finland Oyj vs Giesecke & Devrient Gmbh order on 19 February 2013 case number T 0662/10. The invention is relating to the method for the utilisation of applications stored on a subscriber identity module (SIM) and for the secure treatment of information associated with them, the closest article disclosed is Digital cellular telecommunications systems; Specification of the Subscriber Identity Module – Mobile Equipment interface (ME). 
Comparisons were made and with respect to the claims, appellant 1 specifically argued that the claimed system required more than one operating mode to be available for selection by a respective predetermined code. The board however noted that the presence of more than one operating mode is known from prior art and that the selection between them would have been obvious to the skilled person and the reasons were pointed out. 
The two reasons pointed out were: 
I.            The term "subset mode" had no specific meaning in the art, it is understood by the board in its broadest sense and, hence, includes a communication mode. This understanding was not changed by the statement in the description of the patent in suit that a "subset mode" is used as a synonym for a "security mode" , since a communication mode which uses ciphering keys, as in GSM, may also be understood as a security mode. Further, the board did not see any difference between a "normal" communication mode, as referred to in the claim, and a communication mode. 
With this understanding, which is at variance with that of the opposition division, the problem underlying the claimed subject-matter when starting from prior art may be seen in expanding the functions of the known SIM card in order to give the user a choice between several usage modes, at least one of which comprises a restricted right of access. 
II.            The problem and its solution were already suggested to the skilled person by the prior art. The file structure shown in prior art includes at the same level as DFGSM the further files DFTELECOM and DFIS-41. Prior art is specifically concerned with the interface between the SIM and the ME for use during the network operation phase of GSM, with the consequence that after SIM activation the ME selects DFGSM . Considering that further network operation possibilities like DFTELECOM and DFIS-41 exist on the SIM card, it would have been obvious to the skilled person that a user should be able to make use of them.
To know the case in detail please click on the link http://www.epo.org/law-practice/case-law-appeals/pdf/t100662eu1.pdf
Inventive Step is one of the main reasons for revocation of a patent application filed. Statistics suggest that 43% of the patents have been revoked due to lack of inventive step. So it’s always in the best of interest that a prior art search is done before the priority date and follow the problem-solution approach, and arrive at a point wherein an individual or an applicant can be confident enough to go ahead with the patent application. In addition, when a prior art compared with the invention to be claimed has found to lack inventive step, then the applicant should make sufficient improvement/modification that were left out in the prior art. To conclude with a prior art search is a must before filing a patent application so that one can avoid the cost of legal proceedings.
You may be interested in reading our related articles:
Feel free to contact us or ask us  a question and have it answered within 24 hours. 


Determination of Obviousness/Inventive Step in United states of America

Introduction – Non obviousness

Non obviousness is one of the essential patentability requirements to obtain a patent in United States, as stated under section 35 U.S.C. § 103. The purpose of including a non-obviousness requirement is to encourage innovations that are not mere combination of prior art, without any technical advancement.  

 Title 35, United States Code 103(a):

 A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art, to which said subject matter pertains.
The U.S. Patent Act of 1952 added 35 U.S.C. § 103, which effectively codified non obviousness as a requirement to obtain a patent. Hotchkiss vs. Greenwood, 52 U.S. 248 (1850), was the first US Supreme Court case to introduce the concept of non-obviousness as a requirement of patentability. Prior to the patent act 1952, novelty and utility were the only grounds for patentability. The Supreme Court first attempted to articulate the process for determining non obviousness in Graham v. John Deere (1966). The Court held that non obviousness could be determined by: 
  • Determining the scope and content of prior art 
  • Analysing the differences between the prior art and the claims at issue
  • The level of ordinary skill in the pertinent art 
  • Evaluating evidence of secondary considerations. Secondary considerations include commercial success, a long felt but unmet need for a device, and the failure of others to solve the particular problem addressed by the invention in question. 

Further, the Supreme Court in KSR v. Teleflex case identified a number of rationales to support a conclusion of obviousness, which are consistent with the proper “functional approach” to the determination of obviousness as laid down in Graham. 

Case Law:

Teleflex, Inc. sued KSR International, claiming that one of KSR's products infringed Teleflex's US 6237565 entitled “Adjustable pedal assembly with electronic throttle control”. KSR argued that claim 4 of US 6237565 was obvious under 35 U.S.C. § 103 and therefore invalid. The district court ruled in favor of KSR, but the Court of Appeals for the Federal Circuit reversed the order in January 2005. However, on April 30, 2007, the Supreme Court unanimously reversed the judgment of the Federal Circuit, stating that claim 4 of US 6237565 was obvious under the requirements of 35 U.S.C. §103. 

Guidelines to evaluate obviousness 

Combination of prior art elements: 

One of the steps to determine obviousness is to articulate whether the claimed invention is a result of mere combination of prior art elements. It is always desirable to find, if a person skilled in the art can come up with the claimed invention by combining the elements of known methods, wherein each element would have performed the same function as it would have separately. Sundance, Inc. v. DeMonte Fabricating Ltd is a hallmark case for revocation of patent based on aforementioned statement. Sundance, Inc invention was related to a segmented and mechanized cover for trucks, swimming pools, or other structures. Sundance, had sued DeMonte Fabricating Ltd for infringement of their US patent 5026109. However, DeMonte Fabricating Ltd argued that claim 1 of US patent 5026109 was invalid and obvious citing two prior art references. The first prior art reference  taught a reason for making a segmented cover with ease of repair, in which a single damaged segment could be readily removed and replaced when necessary. A second prior art reference taught the advantages of a mechanized cover for ease of opening. The Federal Circuit noted that the first reference and the second reference would perform in the same manner it would have individually, even after combination. Therefore, it was obvious for a person of ordinary skill in the art  to expect that addition of replaceable segments as taught by the first reference to the mechanized cover of the other would result in a cover that maintained the advantageous properties of both of the prior art covers

Substitution of elements to obtain predictable results 

Substitution of an element by another element (analogue) performing similar function is considered as one of the grounds for determination of obviousness. In re Fout, 675 F.2d 297, 213 USPQ 532 (CCPA 1982) had claimed decaffeinating coffee or tea from fatty material. In re Fout, had substituted an evaporative distillation step for separating caffeine from oil. However, prior art disclosed an aqueous extraction step (Pagliaro) and direct distillation process (Waterman) for decaffeinating coffee or tea from fatty material. The court stated that both Pagliaro and Waterman taught a method for separating caffeine from oil and therefore, it is obvious for a person skilled in art to substitute a method for another performing similar function. 

Known technique to improve similar devices: 

A method is said to be obvious if it enhances a particular class of devices (methods, or products) known in the prior art by using a known technique. In re Nilssen case, the invention was directed to a means by which the inverter can be disabled if current exceeded pre-established threshold level for a specified period. The United States Patent and Trademark Office Board of Patent Appeals and Interference rejected claims 1-4, 9-11, and 16 of Nilssen's patent application Serial No. 476,150 on the ground of obviousness citing two prior art references as provided below: The first prior art USSR Certificate No. 729,738, described a device for indicating the high-load condition via a control means in an inverter, but did not indicate the specific manner of overload protection.The second prior art U.S. Patent No. 3,305,793(Kammiller) disclosed disabling the inverter circuit by means of a cut off switch if there exist a high load current condition. The federal circuit stated that it would have been obvious to one of ordinary skill in the art to use the threshold signal produced in the USSR device to activate a cut off switch to render the inverter inoperative as taught by Kammiller. 

Applying a known technique to a known device (method, or product) ready for improvement to yield predictable results 

Applying a known technique to a known device (method or product) for improvement of the device, and finding that the results obtained over such improvement would have been predictable by a person of ordinary skill in the art can be considered as obviousness. Nilssen case can be cited in this context as well.  

Obvious to try 

The concept of “obvious to try” is a quite sensible requirement for determination of obviousness. “Obvious to try” can be examined as follows:

  • The need for designing the claimed invention to solve a problem being recognised at the time of invention.

  • Existence of a finite number of known solutions for the problem recognised

  • Implementing one of the known solutions, which is obvious to a person skilled in the art for solving the problem recognised.

Pfizer, Inc. v. Apotex, Inc 

Pfizer had been selling amlodipine besylate drug in tablet form under the trademark Norvasc® in U.S. At the time of invention of amlodipine besylate, amlodipine (Apotex) was known to posses similar therapeutic properties as were claimed by Pfizer for amlodipine besylate. Pfizer however, argued stating that amlodipine besylate had better manufacturing property as compared to amlodipine.

Court’s decision: 

The court found that a person skilled in the art would have obviously tried to formulate the salt form of the compound, if he had problems with the machinability of amlodipine and would have been able to narrow the group of potential salt-formers to a group of 53 anions known to form pharmaceutically acceptable salts, which would be an acceptable number to achieve “a reasonable expectation of success.”

Known work in one field of endeavor may prompt variations of it for use in either the same field or a different one based on design incentives or other market forces if the variations are predictable to one of ordinary skill in the art

The scope and content of the prior art, whether in the same field of endeavor as that of the applicant’s invention or a different field of endeavor, including a similar or analogous device should be identified to examine obviousness. Further, design incentives or market forces prompting to adaptation of the known device (method, or product); the differences between the claimed invention and the prior art encompassed in known variations or in a principle known in the prior art are important aspects for determining obviousness relating to the claimed invention. In addition to the above mentioned criteria for determining obviousness, it is also essential to know how a person with ordinary skill in the art, in view of the identified design incentives or other market forces, would have implemented the claimed variation of the prior art, and how would have been the claimed variation predictable to a person of ordinary skill in the art.

The claimed invention in Ex parte Catan, 83 USPQ2d 1568 (bd. Pat. App. & Int. 2007) was a consumer electronics device using bio authentication for enabling sub users to place orders up to a preset maximum credit over.

The first prior art (Nakano) disclosed a consumer electronics device like the claimed invention, which provided security through a password authentication rather than a bio authentication device. The second prior art (Harada) disclosed the use of a bio authentication device (fingerprint sensor) on a consumer electronics device (remote control) to provide bio authentication information (fingerprint). The third prior art (Dethloff) disclosed that it was known in the art at the time of the invention, to substitute bio authentication for PIN authentication to enable a user to access credit via a consumer electronics device.

The Board stated that a person with ordinary skill in the consumer electronic device domain at the time of the invention would have been familiar with using bio authentication information interchangeably with or in lieu of PINs to authenticate users. The Board concluded that it would be obvious to a person with ordinary skill in the art of consumer electronic devices to update the prior art password device with the modern bio authentication component and thereby gain, a secure and reliable authentication procedure.

TSM test 

TSM stands for teaching, suggestion and motivation. A claimed invention fulfils the requirement of being non obviousness, if combination of know elements, which forms the invention, not motivated, suggested or taught in prior art. 


The very fact that a number of approaches have been suggested to determine whether a proposed invention is obvious or not, is an evidence that determining obviousness is a complex subject. Hence, it is important for patent professionals to be abreast with the subject, so that informed advice can be provided to clients at least based on existing guidelines.

You may be interested in reading our articles:


eel free to contact us or ask us  a question and have it answered within 24 hours. 
This work is licensed under a  Creative Commons Attribution-NonCommercial 3.0 Unported License

Determination of Obviousness/Inventive Step- Indian Approach

Patentability requirements

For an invention to be patentable:

  •  it has to be novel (new)
  • it has to involve an inventive step (non-obvious)
  • it has to be industrially applicable (can be made or used in an industry)
Apart from satisfying these criteria, the invention should also not fall under the category of non patentable subject matter, as per Section 3 of the Indian Patent Act.
It is important that before applying for a patent, one tries to ascertain whether the proposed invention satisfies all these criteria for the successful grant of a patent for a proposed invention. The criteria related to novelty and industrial applicability are generally regarded as being well defined and understood based on the definition provided in the Act. However, the concept of non obviousness or the presence of inventive step in a proposed invention is still under debate among the patent office, courts and patentees.

Indian defining of “Invention” – History and Evolution   

 First definition, 1972  

“Invention” means any new and useful-   

(i) art, process, method or manner of manufacture;   

(ii) machine, apparatus or other article;   

(iii) substance produced by manufacture.  

and includes any new and useful improvement of any of them, and an alleged invention.

As can be seen above, the phrase “inventive step” was not even included in the definition.  

Second definition, 2002  

(i). “invention” means a new product or process involving an inventive step and      capable of industrial application;  

(ii) “inventive step” means a feature that makes the invention not obvious to a       person skilled in the art.

The phase “inventive step” was included in the definition of “invention”. Further, the phrase “inventive step” was also defined.

Current definition, 2005:   

(i). “invention” means a new product or process involving an inventive step and capable of industrial application;   

(ii) “inventive step” means a feature of an invention that involves technical advance as compared to the existing knowledge or having economic significance or both and that makes the invention not obvious to a person skilled in the art.

The definition of the phrase “inventive step” was amended to broaden the scope of “inventive step”.  

“Inventive Step” as laid by the Indian Patent Act

The term “inventive step” plays a vital role in deciding whether a patent should be granted to a proposed invention.

As per sec 2 (l) of the Patents Act, a new invention means any invention or technology which has not been anticipated by publication in any document or used in the country or elsewhere in the world before the date of filing of patent application with complete specification, i.e., the subject matter has not fallen in public domain or that it does not form part of the state of the art.

In 2005, India, for the first time, defined as to what constitutes an "inventive step" by incorporating a new provision in the definition section of the Patents Act. Section 2(1)(ja) of the Act defines "inventive step" to mean "a feature of an invention that involves technical advance as compared to the existing knowledge or having economic significance or both and that makes the invention not obvious to a person skilled in the art".
If an invention lacks the presence of an inventive step, then, this deficiency can be considered as valid grounds for opposition for the grant of a patent, under section 25 (1)(e) and 25 (2)(e) and for revocation under section 64 (1)(f) of the Act.    

Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries: Case Law Interpretation on Inventive step

This case can be considered to be the most important case in interpretation of inventive step in the Indian jurisdiction. Though the case was decided in 1978, the principles laid down in the case are followed even today and have been codified in the Indian Patent Act.

The plaintiff (Hindustan Metal Industries, a registered partnership firm carrying on the business of manufacturing brass and German silver utensils at Mirzapur) in this case claimed to have invented a device and method for manufacturing utensils, introducing improvement, convenience, speed, safety and  better finish, in the  old prevalent method which was fraught with  risk to the workers, in as much as the utensils used to fly off from the headstock, during the manufacturing process. The plaintiff got the invention patented, as an assignee, under the Indian Patent and Designs Act, 1911 on May 6, 1951 with effect from December 13, 1951. In September1952, the plaintiff learnt that the defendant (Bishwanath Prasad Radhey Shyam, a concern carrying on the business of manufacturing dishes and utensils in Mirzapur) was using and employing the method under the former’s patent. The plaintiff served a notice upon the defendant asking him to desist from infringing the plaintiff’s patent and further claim damages for Rs. 3000. The validity of the patent was challenged by defendants on the ground of lack of novelty and inventive step and also filed a counter claim praying for the revocation of the plaintiff’s patent on the same ground. A division bench of a district court of Allahabad started its analysis of inventive step and after considering the prior art in the case, stated that the patented invention was merely an application of an old invention, known for several decades before the plaintiff’s patent,  which was no more than a workshop improvement. The court as a result had issued the petition for revocation on the patent. The plaintitiff made appeals to a division bench of the High Court, where the appellate bench concluded that the method of manufacture did not involve any inventive step or novelty. Furthermore, as the invention was publicly used by the patent holder before the date of filing of the patent application, the Court observed that the novelty of the invention was negated. In the light of its analysis, the court concluded that the invention lacked novelty and inventive step. 

Assessment of Inventive Step

If, a product or a process is novel, the next question that arises is "Is the approach obvious and if it not then what is the depth of the inventive measures taken by the inventor”. To determine obviousness is to find out whether the person, with ordinary skill in the art, would have come up with similar innovation for the technical problem under similar circumstances without being provided with the solution.

Since the Patents Act (1970) was brought into force, there have been a few cases in India that have dealt with the obviousness issue extensively. The Supreme Court held that obviousness has to be strictly and objectively judged. The Supreme Court further recognized that obviousness is something that is a natural suggestion of what was previously known.

A test to determine whether a document can negate the existence of inventive step is as follows:

Had the document been placed in the hands of a competent craftsman (or engineer as distinguished from a mere artisan), endowed with the common general knowledge at the 'priority date', who was faced with the problem solved by a patentee but without knowledge of the patented invention, would he have said, "this gives me what I want". To put it in another form: "was it for practical purposes obvious to a skilled worker, in the field concerned, in the state of knowledge existing at the date of the patent to be found in the literature then available to him, that he would or should make the invention the subject of the claim concerned?” 

Novartis v. Union of India case law interpretation on Obviousness  

Novartis filed an application for grant of patent for chemical compound called Imatinib Mesylate which is a therapeutic drug for chronic myeloid leukemia and certain kinds of tumours and is marketed under the names “Glivec” or “Gleevec” at the Chennai Patent Office on July 17, 1998. In the application it claimed that the invented product, the beta crystal form of Imatinib Mesylate, has  more beneficial flow properties better thermodynamic stability and lower hygroscopicity than the alpha crystal form of Imatinib Mesylate and further claimed that the aforesaid properties makes the invented product novel. The patent application had attracted five (5) pre-grant oppositions in terms of section 25(1) of the Act. The Assistant Controller of Patents and Designs heard all the parties, on December 15, 2005, as provided under rule 55 of the Patent Rules, 2003, and rejected the appellant’s (Novartis) application for grant of patent to the subject by 5 (five) separate, though similar, orders passed on January 25, 2006 on the opposition petitions. The Assistant Controller held that the invention claimed by the appellant was anticipated by prior publication, i.e., the Zimmermann patent; that the invention claimed by the appellant was obvious to a person skilled in the art in view of the disclosure provided in the Zimmermann patent specifications. The Supreme Court of India rejected Novartis patent plea on April 1, 2013
Person skilled in the art                                                  

Obviousness is judged based on the hypothetical construct of a "person of ordinary skill in the art". The person of ordinary skill in the art must:

  • belong to the relevant field.
  • look at the prior art from a position of his personality, considering his/her interest in risk taking.
  • be well aware of the fact that even a small structural change in a product or in a procedure can produce dramatic functional changes.
The person of ordinary skills in the art must be given the problem and asked whether he can solve it. This is what is referred to as the 'Hindsight Element'. Obviousness is not established by drawing a line from the solution to the problem, or by finding the explanation for how the inventor did it. It is not permissible to look at the invention and try and figure out the logic behind it and then look for prior art documents which support disclosures throwing light on such logic. Therefore, the person of ordinary skill in the art would constantly be conditioned by the prior art and, before taking action, would carefully ponder any possible modification, change or adjustment against the background of the existing knowledge.  

India has been witnessing an increase in patent enforcement activities. Going forward, one can anticipate much more refined tests for determining the presence of inventive step in inventions. It is recommended that patent practitioner keep themselves educated about this fascinating topic of “inventive step/obviousness” and provide informed opinions.

You may be interested in reading our articles:


Feel free to contact us or ask us  a question and have it answered within 24 hours. 
This work is licensed under a  
Creative Commons Attribution-NonCommercial 3.0 Unported License

How can I find out if my invention has already been invented?

This question may get asked when,

Researchers, before investing their time and money, would want to know, if it’s worthwhile to research on a product.  They would want to find out, what kind of similar products exists in the market and what technological improvements can be made to those products.

For any new technological improvements/inventions, inventors may want to patent their invention. Before starting the process of patenting, inventors would want to access their chances of patentability of the invention. In order to access the patentability of an invention, a search to identify prior art is required.

When a product is to be launched into the market, to avoid infringement, it is advisable to determine freedom to operate for the product in question. In order to determine Freedom to operate, a search of patent documents of the jurisdiction in question is to be conducted. To know more about freedom to operate, you can go through our article about Freedom to Operate

Different strategies can be adopted to determine the answers to the above scenarios:

A search for prior art can be conducted on the internet using search engines. This strategy may uncover some data, but will not always uncover  very relevant data. This is owing to the fact that patent documents and publications may not have been indexed in search engines. Search strategies involved in searching of relevant patent and non patent data requires considerable skill and technique. To know more about search strategies and techniques to be adopted, you can read our article How to conduct a patent search

Another strategy to be adopted is to Search for non patent literature. Searching of non patent literature can aid in finding out if a similar invention exists. Searching of non patent literature be conducted using databases such as  IEEE, Science Direct, IPmenu which hold enormous amount of data relating to non patent literature. Searching of such non patent literature data can uncover similar technology and would help in taking an informed decision regarding the invention. If a similar technology exists in non patent literature, it will affect the patentability of the invention, but it will have no bearing on the freedom to operate for a product, as non patent literature does not provide rights to the owner of that publication from stopping others from making and selling of those products.Note that if a publication about an invention exists in non patent literature, it does not mean that the owners would not have sought patent protection as well. It is advisable to cross check patent data as well before taking a decision about Freedom to operate.

 Another strategy to be adopted is to search patent literature. Searching of patent literature can be conducted using various free and paid patent databases. It is important to know a few facts about patents.

Patents are jurisdiction specific. It means that to obtain patent protection, one has to file for patents in all the jurisdictions one wishes to obtain protection. 

While determining freedom to operate for a specific country, only patent documents from that jurisdiction are to be considered. 

To determine the patentability of an invention, one needs to consider relevant patent documents from all jurisdictions.

I hope you find this article helpful. Check our  patent services page to find out if we can cater to your patent requirements. Also feel free to contact us or ask us a question and have it answered within 24 hours.
This work is licensed under a

Is my product infringing on others patents?

This is the question all technology companies need to ask themselves at a very early stage of product development.To understand whether you product/process infringes on others patent rights; we first need to understand what patent infringement means. 

Patent infringement
A patent is said to be infringed when a product/process violates the rights granted to a patentee. A patentee (also referred to as an assignee of a patent) is given the rights to exclude others from making, using, importing, selling or offering for sale the patented invention for up to 20 years. This scope of protection granted to a patentee gives him the right to take legal action against the infringing parties.
How do we determine if a product/process infringes upon a patent?
To determine infringement of a patent by a product/process, one has to go through a section of a patent document called the claims. The claims section of a patent document describes in detail, the scope of protection granted to a patent.
The claims have to be analyzed in detail to find out if a product/process infringes upon the rights of a patentee. Depending on the nature of the claim, the claim would include a number of elements or process steps. Subsequently the scope of each of the elements/process steps has to be determined. Thereafter, your product/process has to be compared with the elements/process steps of the claim. The above comparison helps you determine whether the claimed elements/steps exist in your product/process.
A claim is said to be infringed if all the elements of the claim exists in your product. Similarly, a claim that includes process steps is said to be infringed, if all the process steps are present in the process that you intend to follow. 
In other words, if all the elements in the claims of the patent map on to the features of your product, your product is infringing upon the patent rights of the patentee.
It should be noted that, if your product does not have at least one element of the claim, then your product does not infringe upon the patent rights of the patentee. This analysis of infringement is carried out by well established doctrines developed over many years. This analysis is generally referred to as infringement analysis study/product mapping/claim mapping.
Now to give you an idea of how this works let me explain with an example.
Let’s take an example relating to a patent for a car seat, the claim describes a car seat which can be electronically height adjusted, backrest can be adjusted, and the seat can slide forward and backward. Now you should check whether all the elements of the patent claim appear in your product, i.e. whether your car seat product has an electronically height adjustable feature along with adjustable backrest and forward and backward sliding seat, if so, your product infringes upon the patent rights of the patentee.
If your product has all the features of the elements of the claim of the patent and has additional features like seat warmers, even then your product infringes upon the patent.
If your product does not have at least one feature mentioned in the elements of the claim, such as electronically height adjusting, but has the remaining features, then your product does not infringe upon the patent.    
I hope you found this article useful. Feel free to contact us for any information that you may require.
You can visit our website to know more about the patent services that we offer.
You can download a copy of this article here
Thank you,
Team InvnTree