Eyeball Rotation Measurement Using Head-Mounted Visual Targets

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Solution Overview

Problem

Conventional methods for measuring rotation characteristics of an eyeball, such as those using a line-of-sight information correction device, face challenges in accurately capturing these characteristics due to slight head or body movements by the subject, especially when rotation characteristics are near their limits, leading to inaccuracies in measuring rotation characteristics.

Innovation Solution

A method utilizing a head-mounted display secured to the subject's head, which changes display information position and content to determine the range of recognition, enabling accurate measurement of rotation characteristics by assessing the subject's ability to recognize displayed content at various positions and angles, with adjustments for eyeglass lenses if worn.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a headband-mounted eyeball photographing camera is used to measure line-of-sight information, then line-of-sight information can be obtained, but measurement accuracy deteriorates when the subject moves their head or body slightly

Engineering Contradiction:
Improveline-of-sight information accuracyVSAvoidmeasurement stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a head-mounted display as an intermediary device that presents visual targets directly to the subject's eyes. This mediator enables precise control of the viewing target position while the subject's head remains relatively stable, allowing accurate measurement of eyeball rotation characteristics without requiring the subject to move their head or body

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a feedback mechanism where the system presents visual targets at specific positions and angles, measures the subject's visual response and eyeball rotation, and uses this information to adjust and refine subsequent measurements. This feedback loop enables accurate determination of rotation characteristics even when minor head movements occur, as the system can compensate and recalculate based on observed responses

Inventive Principle:
Principle #23Feedback

2Measurement precision

If display information is shown at positions separated from reference position to measure rotation characteristics, then rotation range can be assessed, but measurement accuracy deteriorates due to head or body movement

Engineering Contradiction:
Improverotation characteristics accuracyVSAvoidhead and body movement interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by having the subject wear the head-mounted display and establish a stable head position before beginning the rotation characteristics measurement. The reference position is pre-established, and the measurement process begins with the subject's head already in the correct position, preventing movement interference during the actual measurement of rotation characteristics

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the measurement process into distinct phases: first establishing the reference position with the head in a stable state, then measuring rotation characteristics by presenting display information at separated positions while maintaining head stability. This segmentation allows the system to isolate and measure pure eyeball rotation without confounding head movement effects

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3951482B1Measuring method for measuring rotation characteristic of eyeball of subject and setting method for progressive power lens
Publication Date: 2026.03.11 HOYA LENS THAILAND LTD
  • EP3951482B1 patent drawingFigure 1
  • EP3951482B1 patent drawingFigure 2A~2B
  • EP3951482B1 patent drawingFigure 3

AI summary

A measuring method for measuring rotation characteristics of an eyeball of a subject includes: showing display information on a display screen, at a position separated from a reference position, the display screen being shown in front of the eyeball of the subject by a display device that is secured to a head of the subject, the reference position being where a front line of sight of the eyeball of the subject who looks forward straightly, crosses the display screen; changing a direction of a line of sight from the eyeball to the display information by switching the display information to other contents while changing a displayed position of the display information; and judging whether the subject can recognize the contents of the display information at the changed position, to measure the rotation characteristics of the eyeball.