Dual-Display Wearable IPD Control Using Hall Sensor Feedback

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Solution Overview

Problem

Existing head-mounted devices (HMDs) fail to accurately adjust the inter-pupillary distance (IPD) between displays, leading to blurry images and user discomfort due to varying IPDs among users, despite manual user adjustments.

Innovation Solution

A wearable electronic device with a hall sensor, magnet, and processor that adjusts the distance between displays based on magnetic force data, using a movable magnet within a specified range to determine the optimal IPD.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual adjustment method is used to set inter-display distance, then user can adjust the distance between displays, but the displayed image does not match the current inter-display distance, resulting in blurry images and eye fatigue

Engineering Contradiction:
Improvemanual adjustment capabilityVSAvoidimage clarity
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the purely mechanical manual adjustment system with a hybrid system that incorporates magnetic sensors (hall sensors) to detect magnet position. This substitution allows the device to automatically determine inter-pupillary distance based on magnetic field data, resolving the contradiction between manual adjustability and image clarity by providing precise digital measurement of the physical distance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback mechanism where the hall sensor continuously monitors magnet position, and the processor uses this data to adjust display parameters accordingly. The system provides visual feedback to the user through indicators showing when optimal positioning is achieved, creating a closed-loop control system that ensures both ease of adjustment and image clarity.

Inventive Principle:
Principle #23Feedback

2Device complexity

If fixed inter-display distance is used in HMD devices, then device structure is simplified, but it cannot adapt to varying IPDs among different users

Engineering Contradiction:
Improvestructural simplicityVSAvoidIPD adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent transforms the fixed inter-display distance structure into a dynamic, adjustable system. By incorporating a movable magnet coupled to the display assembly and a hall sensor for detection, the system can adapt its configuration to match different users' IPDs while maintaining relative structural simplicity through the use of magnetic coupling rather than complex mechanical linkages.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces a magnet as an intermediary element that couples the adjustment mechanism to the display assembly. This magnet serves as a mediator that translates user adjustment actions into precise display positioning without requiring direct mechanical connection between the adjustment interface and the displays, thereby maintaining structural simplicity while enabling adaptability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If mechanical adjustment mechanism is used to change inter-display distance, then user can set distance for her eyes, but the device fails to display screen according to current inter-display distance

Engineering Contradiction:
Improvedistance setting capabilityVSAvoiddistance information accuracy
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The patent replaces mechanical distance measurement methods with magnetic field-based detection using hall sensors. This substitution eliminates the information loss inherent in mechanical systems by providing precise digital measurement of the magnet's position, which directly corresponds to the inter-display distance, thereby maintaining ease of operation while ensuring accurate distance information is captured and utilized.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Accurately adjusts the IPD for individual users, ensuring clear images and reducing eye fatigue by aligning displays with the user's specific IPD, enhancing the VR, AR, and MR experience.

Implementation Method 1

obtain magnetic force data in a plurality of directions through the hall sensor while the magnet moves from a first end to a second end of the specified range

Methodology Applied
Scientific EffectMagnetic force detection: Hall Effect

Data Source

PatentEP4435585B1Wearable electronic device comprising plurality of displays, and method for controlling same
Publication Date: 2026.03.04 SAMSUNG ELECTRONICS CO LTD
  • EP4435585B1 patent drawingFigure 1
  • EP4435585B1 patent drawingFigure 2
  • EP4435585B1 patent drawingFigure 3A~3B

AI summary

According to an embodiment, a wearable electronic device may comprise a hall sensor, a magnet, a first display, a second display disposed side by side with the first display, and at least one processor operatively connected to the hall sensor, the first display, and the second display. The magnet may move linearly in a first direction parallel to a direction in which the first display and the second display are disposed, by the same distance to the left and right with respect to the hall sensor, corresponding to a distance between the first display and the second display. The at least one processor may obtain magnetic force data in a plurality of directions through the hall sensor while the magnet moves from a first end to a second end of a movable distance in response to a change in the distance between the first display and the second display and obtain relationship information between and magnetic force data and the distance between the first display and the second display, based on magnetic force data in the first direction and magnetic force data in the second direction among the magnetic force data in the plurality of directions.