Silent Answer, Loud Delay: What the Xiaomi Find Device Patent Case Teaches Patentees

Summary

Conqueror Innovations sued Xiaomi Technology India over its Find Device feature, claiming infringement of Patent 244963 for a communication device finder system. A Single Judge refused an interim injunction, and the Delhi High Court Division Bench upheld that refusal on appeal. The Division Bench held that Find Device lacks the non-erasable message centre number retention and the silent auto-answer mode that the claim requires, and that nine years of delay independently barred interim relief. The ruling shows that a patentee must map every essential claim element to the accused product and act promptly once it knows of the alleged infringement.

Background

With barely two months left on a patent in court since 2023, the Delhi High Court was asked to restrain a smartphone maker’s remote device-recovery feature in the Xiaomi Find Device patent case.

Conqueror Innovations Private Limited and another (“Conqueror”) hold Indian Patent 244963 under the Patents Act, 1970 (“Patents Act”), titled “A Communication Device Finder System”, filed on 17 October 2006 and granted on 28 December 2010. The patent is set to expire on 17 October 2026. Independent Claim 1 covers a device with a security activation element, defined by two features following the words “characterized in that”: a flash memory with auto re-install option, or a non-erasable read only memory (“ROM”), holding data including the message centre number (Element E2); and an activation mechanism that places the device in an “auto-answer mode” with no visual or voice cues (Element E3). Dependent Claims 2, 4, 5 and 9 add tracking, sound and erasure functions.

Xiaomi Technology India Private Limited (“Xiaomi”) has sold phones in India since 2014. Its “Find Device” feature lets an owner ring, lock or erase a lost phone remotely. Conqueror sued on 19 May 2023, alleging that Find Device infringes the patent, and sought an interim injunction. On 4 July 2025, the Single Judge dismissed the applications, finding no prima facie case of infringement, noting that the balance of convenience favoured Xiaomi, and recording a nine-year gap between grant and suit. Conqueror appealed, and the Division Bench reserved judgment on 3 August 2026 before pronouncing it on 7 September 2026.

Issues

1. 1. Whether Xiaomi’s Find Device meets Element E2 of Claim 1 of Patent 244963, which requires a flash memory with auto re-install option or a non-erasable ROM containing data including the message centre number.
   2. Whether Find Device meets Element E3, and whether “auto-answer mode” means silent answering of incoming calls or covers remote activation alone.
   3. Whether Dependent Claims 2, 4, 5 and 9 can support infringement when Independent Claim 1 is not made out.
   4. Whether a gap of about nine years between grant and suit, and limited working shown in the patentee’s statements of working, justified refusal of interim relief with the patent expiring on 17 October 2026.

Conqueror’s Arguments

• • Element E2 offers flash memory and ROM as disjunctive alternatives, so Find Device, stored in ROM as a non-erasable anti-theft feature, satisfies it on its own.
  • Requiring the message centre number to sit in ROM is technically impossible and erroneously narrows the claim, so the Single Judge wrongly imposed that condition.
  • “Auto-answer mode” in Element E3 means remote activation, and triggering Find Device through a Xiaomi account meets it; importing the specification’s definition of silent answering into the claim was an error.
  • Conqueror learnt of the alleged infringement only in January 2023, non-working is not an absolute bar to an infringement action, and damages cannot adequately compensate for loss of patent rights.

Xiaomi’s Arguments

• • Conqueror changed its case on appeal: the plaint and claim chart relied on third-party anti-theft applications to make data non-erasable, not on native ROM storage.
  • The message centre number is network and SIM dependent data that cannot be permanently stored in ROM, and Element E2 requires non-erasable retention of that data.
  • “Auto-answer mode” has a specific meaning in the specification, namely answering calls at the first ring with no cue so an owner can hear the surroundings, and Conqueror’s own claim chart adopted it.
  • Remote activation was already known from prior art (US 7,103,367 and EP 1684535), and Find Device only rings, locks or erases, without silent call answering or auto re-installation of deleted data.
  • Absence of any one essential element defeats infringement, and Conqueror’s 2015 statement of working showed awareness of similar technology, making the 2023 suit delayed.

Court’s Analysis

Why storage in ROM alone does not satisfy the security activation element

The court noted that the Single Judge rightly treated the features after “characterized in that” as the novel features that Conqueror had to find in the accused product. The court observed that the plaint and claim chart pleaded infringement through third-party security applications, while the appeal narrowed the case to native ROM storage, which the court held was a new case. The court further observed that Element E2 speaks of non-erasable retention of data including the message centre number. The court reasoned that Conqueror conceded Xiaomi’s devices hold that number in neither flash memory nor ROM and offered no explanation of how the element could operate without it.

Auto-answer mode means silent answering, not remote triggering

The court held that the specification itself defines auto-answer mode as answering all incoming calls at the first ring, along with silent mode, so that the caller can hear conversations around a stolen device. The court noted that Conqueror itself pleaded this functionality before the Single Judge, and rejected the argument that the definition was imported into the claim. The court stated that remote triggering was admittedly known from prior art, so a reading that equated auto-answer mode with remote activation would expose the claim to invalidity attacks. The court found that Find Device rings, locks or erases but never answers calls silently, and that it becomes unusable after a factory reset. The court observed that Find Device protects data rather than recovering a device, so the Xiaomi Find Device patent case could not clear Element E3.

Dependent claims cannot rescue a missing essential feature

The court opined that where Independent Claim 1 is not prima facie infringed, Dependent Claims 2, 4, 5 and 9 cannot succeed, because each incorporates the limitations of the claim on which it depends.

Nine years of silence and two months of life left

The court observed that Xiaomi had sold phones in India since 2014, that the patent was granted in 2010, and that suit came in 2023. The court found Conqueror’s claim of knowledge only in January 2023 unconvincing, since its 2015 statement of working to the Patent Office acknowledged smartphone makers using similar technology. The court held that such prolonged and conscious delay showed no urgency and independently justified refusing interim relief. The court further noted, relying on Novo Nordisk A/S v. Dr. Reddy’s Laboratories Ltd. (2026 DHC 1911-DB), that an injunction on a patent with two months left would bring little practical benefit. The court stated that its observations on the Xiaomi Find Device patent case were prima facie and would not influence the trial.

Findings

In view of the observations and the arguments presented by both the parties, the Division Bench held that:

• • The Single Judge committed no error of principle in construing Elements E2 and E3 of Claim 1 of Patent 244963.
  • Conqueror failed to establish a prima facie case, since Find Device lacks both the non-erasable retention of the message centre number and the silent auto-answer mode.
  • Conqueror could not rely on narrowing its case to ROM storage on appeal, as it departed from the case pleaded in the suit.
  • Dependent Claims 2, 4, 5 and 9 fail along with Independent Claim 1.
  • The delay of about nine years, together with the patent’s imminent expiry on 17 October 2026, independently warranted refusal of interim relief.
  • The appeal and pending applications stand dismissed, and the observations are prima facie, leaving the Single Judge to decide the suit on evidence uninfluenced by them.

Case Citation: Conqueror Innovations Private Limited & Another v. Xiaomi Technology India Private Limited, FAO(OS)(COMM) 147/2025 & CM APPL. 60385/2025, 72055/2025, High Court of Delhi at New Delhi (Division Bench), decided on 7 September 2026.

Single Judge ruling: CS(COMM) 361/2023, order dated 4 July 2025 (interim applications dismissed).

Authored by Gaurav Mishra, IP Attorney, BananaIP Counsels