Workshop Tweaks Aren't Inventions
Facts of the Case:This case involves a challenge to the refusal of a patent application by the Indian Patent Office. The appellant, Saint Gobain Glass France, is a French company that makes and researches various glass products used in buildings, cars, airplanes, solar panels, and interior designs. They filed a patent application in India as part of an international process under the Patent Cooperation Treaty (PCT). The application, numbered 201717045317 and titled "Material comprising a stack of thin layers," claimed priority from a French filing dated 9 July 2015. It was filed in India on 18 December 2017, examined on the same day, and published on 19 January 2018.
The invention describes a special coating for glass that uses layers of materials, including a silver-based metal layer, to create a shiny silver look on the outside while keeping good light transmission and solar energy control. The goal is neutral colors when light passes through and a reflective silver appearance without harming energy efficiency.
During the process, the Patent Office issued a First Examination Report (FER) on 25 April 2019, raising issues like lack of newness (novelty), lack of inventive step, non-patentability under Section 3(d) of the Patents Act, 1970 (which bars mere discoveries or new forms of known substances without enhanced efficacy), and unclear claims under Sections 10(4)(c) and 10(5). The appellant responded on 11 October 2019 by amending the claims, making a lower blocking layer optional.
On 20 August 2019, Respondent No. 2 (an opponent) filed a pre-grant opposition under Section 25(1) of the Act. Hearings happened multiple times in 2023, with more prior art documents shared. The appellant filed replies, affidavits from experts, and further amendments. On 5 January 2024, the Assistant Controller refused the application, mainly because it lacked inventive step under Section 2(1)(ja) of the Act and Section 25(1)(e) (obviousness ground for opposition).
The appellant appealed this refusal under Section 117A of the Patents Act, 1970, to the High Court. An interim order on 11 April 2024 kept the application status as "pending" during the appeal. Oral arguments were heard over several dates in late 2024 and 2025, and judgment was reserved on 11 July 2025.
The Dispute:The core dispute is whether the invention meets the requirements for patentability under the Patents Act, 1970, especially Section 2(1)(ja), which defines "inventive step" as a feature that makes the invention not obvious to a person skilled in the art (a skilled worker in the field). The Controller said no, because the idea was obvious from existing knowledge (prior art)—just tweaking layer thicknesses in known glass coatings to get the desired silver look and reflection over 30%, without real innovation.
The appellant argued the Controller wrongly mixed bits from different old documents (cherry-picking) using hindsight (judging based on the invention itself, not what was known before). They said their invention provides real technical improvements like better neutral colors and solar performance, supported by data and expert evidence. They also claimed a similar patent was granted in France, so it should be in India.
The respondents (Patent Office and opponent) defended the refusal, saying the prior arts already taught similar layer stacks, and the changes were routine adjustments anyone skilled could make.
Detailed Reasoning: The Court applied a structured approach to check for inventive step, drawing from Supreme Court and High Court precedents. It relied on Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries (1979) 2 SCC 511, which says an invention must go beyond simple tweaks or combinations of known things—it needs to create something new or better through real creativity, not just obvious steps. The Court also used the five-step test from the Division Bench in F. Hoffmann-La Roche Ltd. v. Cipla Ltd. (2015 SCC OnLine Del 13619) to test obviousness objectively, without hindsight bias.
Step 1: Who is the 'person skilled in the art'? The Court agreed with the Controller: This is someone familiar with glass building and manufacturing basics, like how to layer coatings for light and energy control.
Step 2: What common knowledge existed before the priority date (9 July 2015)? The Court listed key prior arts (old documents):
Document A (WO 2014/164674): Teaches multi-metal layers for glass coatings.
Document B (WO 2014/177798): Shows silver layers between dielectric and blocking layers for better looks and reflection, but with triple silver (not single) and max 23.7% external reflection.
Document D2 (WO 2011/062574 A1): Describes bronze-colored glass with reflection under 28%, blue transmission, and tips on thickness tweaks for colors and solar performance.
Documents 3022/KOLNP/2010 and 3417/KOLNP/2010: The appellant's own earlier filings, showing single silver layers with 30-50% reflection and thin dielectric layers (5-25 nm), but different setups.
These show that stacking silver between protective layers for reflection and color was already known.
Step 3: What is the inventive concept? The Court saw it as: (i) Using one silver layer with specific surrounding layers for neutral transmission colors; (ii) Getting a glossy silver external reflection over 30% without worsening solar factor (energy gain).
Step 4: Differences from prior art?
Vs. A: A has three metals; invention uses one.
Vs. B: Similar stack, but B requires three silvers and lower reflection (23.7%).
Vs. D2: D2 aims for bronze/blue with lower reflection (<28%); invention wants silver over 30%.
Vs. 3022/KOLNP/2010: Similar reflection goal (30-50%), but different features.
Vs. 3417/KOLNP/2010: Single silver between anti-reflective layers, thin dielectrics.
The main difference: Specific thicknesses for silver look and high reflection without a lower blocking layer.
Step 5: Are these differences obvious (no inventive step)? Here, the Court sided with the Controller. The appellant's data (Tables 2-3) and expert affidavit didn't prove big improvements over prior art—no clear gains in solar factor, transmission, or colors without the optional layer. The expert missed key metrics like energy transmission (ET%) and external reflection (ERext%).
Prior arts (A, B, D2) already sandwich silver between dielectric/blocking layers and teach thickness tweaks for reflection, colors, and solar tweaks. D2 specifically says adjust layers for bronze from blue glass—obvious to try for silver. The appellant's own old filings show they knew single-silver stacks could hit 30-50% reflection and <60% transmission.
The Court rejected "cherry-picking": Combining related teachings from the same field isn't hindsight—it's what a skilled person does to solve similar problems. Citing Bishwanath Prasad, tweaks like thickness optimization are "workshop improvements," not inventions, unless they yield unpredictable new results. Here, outcomes were predictable.
On France grant: Patents are territorial (Communication Components Antenna Inc. v. ACE Technologies Corpn., 2019 SCC OnLine Del 9123). India's standards (e.g., who counts as "skilled") differ; foreign grants don't bind.
The Court said the invention fails Section 2(1)(ja)—obvious routine work. Dependent claims (2-13) add nothing new. No need to revisit other objections like Section 3(d) or clarity, as inventive step alone bars grant.
Decision:The High Court dismissed the appeal on 11 September 2025, upholding the Controller's refusal under Section 2(1)(ja). The pending application (I.A. 8216/2024) was disposed of. The interim order (status as "pending") was vacated. The Registry must send a copy to the Patent Office. No costs awarded. This means no patent for the invention in India, emphasizing that obvious tweaks to known tech don't qualify as inventions.
This ruling reinforces strict scrutiny for inventive step in coatings/glass patents, stressing evidence of non-obvious advances and warning against hindsight in prior art combos. It guides applicants to show real, unpredictable benefits over old knowledge.
Case Title: Saint Gobain Glass France Vs. Assistant Controller of Patents and Designs & Anr.
Order Date: 11 September 2025
Case Number: C.A.(COMM.IPD-PAT) 13/2024
Neutral Citation: 2025:DHC:7941
Name of Court: High Court of Delhi
Name of Hon'ble Judge: Hon'ble Mr. Justice Amit Bansal
Disclaimer: The information shared here is intended to serve the public interest by offering insights and perspectives. However, readers are advised to exercise their own discretion when interpreting and applying this information. The content herein is subjective and may contain errors in perception, interpretation, and presentation.
Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi
