US 9402120

An analysis of US Patent 9,402,120 reveals the following details regarding the invention and its legal status.

Title: Wireless earbuds

Assignee: The current assignee of the patent is Earin AB. The original assignee was Epickal AB.

Inventors: The inventors of this patent are Olle Lindén, Kiril TRAJKOVSKI, Per Sennström, Carl Ståhl, Markus Millfjord, and Henrik Hovmøller.

Filing Date: The patent application was filed on September 5, 2014.

Issue Date: The patent was granted on July 26, 2016.

Abstract: The patent describes a wireless earbud with a specific internal component layout. The earbud housing is essentially cylindrical and contains a loudspeaker, a rechargeable battery, a main printed circuit board (for wireless communication, audio processing, and control), and a charging interface. These components are arranged sequentially along the main longitudinal axis of the earbud.

Overview of Independent Claims:

This patent has four independent claims which define the core aspects of the invention:

Claim 1: This claim details the physical construction of a wireless earbud. It specifies a housing with a generally circular cross-section that contains the main printed circuit board, a rechargeable battery, and a loudspeaker, all arranged in a line. The claim explicitly states the circuit board is located at the distal end (the end furthest from the eardrum), followed by the battery, and then the loudspeaker element closer to the front.

Claim 12: This claim focuses on the placement and design of the antenna within the wireless earbud. It describes an earbud with its internal components arranged in successive order. The key inventive aspect of this claim is that the antenna for the wireless radio is an "elongate radiator pattern" located on the circumference of the main printed circuit board.

Claim 20: This claim describes a method for automatic power preservation and connection management in a wireless earbud. The earbud has an "idle mode" and an "operational mode." It enters idle mode when it detects it is connected to a charger, at which point it disconnects from a second earbud and a host device (e.g., a smartphone). Upon being disconnected from the charger, it enters operational mode, attempts to reconnect to the second earbud for true wireless stereo (TWS), and if it is the "master" device, it will then attempt to reconnect to the host device.

Claim 22: This claim pertains to a wireless audio streaming host device (like a smartphone) that interacts with two wireless earbuds. The host device is configured to receive the battery status from each earbud. Based on the battery levels and the current "master" and "slave" roles of the earbuds, the host device can assess whether to switch these roles between the two earbuds. This allows for more balanced power consumption, as the "master" role typically consumes more power.

Litigation:

As of the current date, US Patent 9,402,120 is the subject of litigation. A search of court records indicates that a lawsuit was filed in the U.S. District Court for the District of Delaware on March 13, 2026. The case is docketed as Earin AB v. Skullcandy, Inc., 1:2026cv00276. I have high confidence in this information based on the direct search result. I do not have authoritative information on the current status or outcome of this specific case from the available search results. A search of the U.S. Court of Appeals for the Federal Circuit (CAFC) dockets for 2026 did not yield any specific results for this patent number, suggesting any appeal has not yet been docketed in 2026 or that the district court case is ongoing.