Claims of a patent specification are of paramount importance as it determine the metes and bounds of protection granted to the patentee. Section 10(4)(c) states that claims define the scope of invention for which protection is sought. An applicant can modify the scope of protection by amending the claims. However, the applicant does not have the liberty to alter/ amend the scope of claims in an unbridled manner. As laid down in the Ayyangar Committee Report, 1959[2], an assessment whether an amendment to the claims is allowable or not, is made by comparing the scope of claims before and after such amendment. An amended claim shall not broaden the scope of the original claim.

            However, it is well settled that addition of limitation to certain features in the original claim results in limiting the scope of the claim. In such circumstances, adding such limitation(s) to the feature in the original claim acts as a disclaimer and the same can be allowed. Therefore, adding features to the claims may not necessarily result in broadening of scope, and therefore, should not be construed unallowable under all circumstances.  

            A current ruling from the Delhi High Court reaffirms the above, while interpreting provisions of Section 59 of the Act.

            In its order dated 08 May 2023, the Hon’ble Delhi High Court has allowed certain features to be added to the principal claim, which is in effect an additional limitation to the said claim, and thereby setting aside the Controller’s refusal u/s 59(1) of the Act.


1.      The application was filed by Sony Corporation on 15th May, 2013 for an invention on DATA PROCESSING DEVICE AND DATA PROCESSING METHOD. The application was a national phase of International application PCT/JP2011/076173 and claimed priority from the JP Patent Application no. 2010-259665 dated 22nd November, 2020.

2.      The First Examination Report was issued on 26 August 2019, pursuant to which the applicant filed a detailed response and amended the claims in line with that of the corresponding EP application.

3.      The oral hearing was appointed and pursuant to which, the applicant amended the claims.

4.      Subsequently, on 16th February, 2022, the applicant further amended the claims 1 to 8, in terms of which, the amended independent claims 1 and 4 corresponded with the independent claims 4 and 10 of the corresponding European Divisional Patent. European Patent no. EP3429084 (B1) was granted on a EP divisional application out of main EP application no. EP2645579, which is counterpart application to the subject application.

5.      The original Indian application corresponded to both the main EP application as well as the EP divisional application. Subsequently, as per the final amendment, applicant gave up its claims corresponding to the main EP application and chose to proceed only with the claims corresponding to the EP divisional application.

6.      The Controller refused the application for the reason that the claims amended on 16th February 2022 were beyond the scope of the original claims. One of the primary reasons for refusal was that, as indicated in his written decision, the amended claims corresponded to the divisional EP patent and not to the parent EP patent, which is counterpart to the instant Indian application.

7.      The decision of the Controller was appealed before the Delhi High Court, and the Hon’ble Justice Amit Bansal, J., has been pleased to hold that the amendment proposed in the claims by the applicant is well within the scope of Section 59(1).

            The basis of his decision is as follows:

            The Hon’ble court has clarified that no negative inference can be drawn against the appellant on account of the fact that amended claims correspond to the granted EP claim of the divisional application.

            Paragraph 13 of the order underlines the fact that when an invention embraces two inventive concepts permissible under 10(5) of the Act, the applicant has full liberty to either drop off or file divisional, with one of inventive concepts.

“In my considered view, the appellant having filed the subject application in respect of two inventive concepts, which was permissible in terms of Section 10(5) of the Act, was at full liberty to give up claims in respect of one of the inventions and only pursue one of them that corresponded with the divisional application of the European patent.”

            It is an undisputed position that both the European Patent, main as well as divisional, corresponded to the application filed in India, and both the patents have been granted in Europe.

Assessing the doctrine of disclaimer in pre grant amendments.

            Conforming to the elementary principles of claim amendment, the ruling has echoed the observation of this Court in AGC Flat Glass Europe v. Anand Mahajan and Others, 2009, that,

“…it has been observed that amendments which limit the scope of the specification to a sub-combination which was within the original claim would be a disclaimer (which can be allowed), and the absence of an appendant claim in the original document to such sub-combination cannot of itself be a reason for refusing the amendment.”

            The disclaimer doctrine thus means that a right holder is delimiting the scope of the invention by narrowing down the claims in a way which makes the amended claims not inconsistent with the earlier claims in the original specification.

            Thus, the law operates differently when it comes to narrowing down or crystallizing the claims and apportioning those claims/subjects which are irrelevant and ultimately making it narrow and limiting the scope of the invention.

The Ayyangar Committee Report when applied to Section 59 of the Act.

            Putting reliance upon Nippon A&L Inc. v. The Controller of Patents, 2022:DHC:2434, the Hon’ble Court further observed that so long as the invention is disclosed in the specification and the claims are being restricted to the disclosures already made in the specification, the amendment ought not be rejected, especially, at the stage of examination prior to grant. When this standard, as also contemplated by the Ayyangar Committee Report, is applied to Section 59 of the Act as it stands today, it becomes clear that amendments to a patent specification or claims prior to grant ought to be construed more liberally rather than narrowly.

            The Report is also categorical in its observation that the invention before and after amendment need not be identical in case of amendment before acceptance “so long as the invention is comprehended within the matter disclosed.”

            In paragraph 12 of the decision the Hon’ble Court held that the amendments are well-supported by the specification filed with the subject application and that the additional feature introduced in the principal claim is in effect an additional limitation to the said claim. The said additional limitation is also supported by the disclosure provided in the complete specification of the subject patent application.

            Hence, the order clarifies that when one or more features added in the principal claim is in effect an additional limitation to the said claim, and the additional limitation is also supported by the original disclosure, the nature of the amendment is to make the scope of the patent more specific and clearer and hence allowable under Section 59 of the Act.


            This is an important decision as it affirms the stand of the judiciary in the case of claim amendment by way of disclaimer. It strengthens the applicant’s right to add new features in the claims from the disclosure, if such addition restricts the scope of the claimed invention. The order would also serve as a useful judicial precedence for applications at various stages of prosecution facing similar constraints with respect to claim amendments.

Author: Dipanjana Chakraborty

Dipanjana Chakraborty

Patent Attorney

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