Proximity Gesture Detection That Ignores Wrist Reflection

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Solution Overview

Problem

Existing display-based operation detection systems, particularly in automotive settings, face issues with incorrect hand position detection due to infrared light reflection from users' wrists and arms, leading to omitted operation acceptance when a hand moves beyond a predetermined threshold distance.

Innovation Solution

A proximity detection device using infrared light sources and photodetectors positioned outside the display to accurately detect hand movement in both left-right and up-down directions, with a notification system to prevent erroneous detection by setting the position immediately before movement decrease as the end position, ensuring operation acceptance when the hand moves beyond a threshold value.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If infrared light is emitted from below the display face to detect hand approach, then hand approach detection is enabled, but erroneous detection occurs due to reflection from user's wrist and arm

Engineering Contradiction:
Improvehand position detection accuracyVSAvoidinfrared light reflection from wrist and arm
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The infrared light source is extracted from below the display face and positioned at the side of the display. This removes the harmful reflection effect caused by light emitting from below, while preserving the hand approach detection function. The light source is now disposed outside the display face in the left-right direction, eliminating the reflection issue from wrists and arms.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a reflective member (diffuse reflector) as an intermediary between the infrared light source and the detection region. This reflector redirects the infrared light from the side position to effectively illuminate the front side of the display face, enabling hand detection without requiring the light source to be positioned below the display where it would cause reflection issues.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If hand movement threshold is set to accept operations, then operation acceptance is enabled, but operations are omitted when hand moves beyond display due to erroneous position detection

Engineering Contradiction:
Improveoperation acceptance rateVSAvoidoperation detection accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system continuously monitors the detected hand position and compares it with the display boundaries. When the detected position indicates the hand has moved beyond the display (erroneously due to reflection), the system provides feedback by determining that no operation should be accepted, even if the movement threshold is met. This feedback mechanism prevents erroneous operation acceptance while maintaining normal operation detection within the display area.

Inventive Principle:
Principle #23Feedback

3Area of stationary object

If display is disposed between driver's seat and passenger's seat, then space utilization is improved, but operation detection becomes unreliable due to user's arm position

Engineering Contradiction:
Improvedisplay placement space utilizationVSAvoidhand position detection accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The infrared light source is positioned asymmetrically at the side of the display rather than symmetrically below it. Specifically, the light source is disposed at one side of the display in the left-right direction, which optimizes the detection angle for the driver's hand movements while avoiding the reflection issues that would occur with symmetric below-display positioning in the vertical direction.

Inventive Principle:
Principle #4Asymmetry

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

This solution effectively suppresses the omission of user operations by accurately detecting hand movements and preventing erroneous position detection due to reflections, ensuring that operations exceeding a predetermined distance are correctly accepted by the data processing device.

Implementation Method 1

detects reflected light of the infrared light reflected by the user's hand

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3926444B1Proximity detection device and information processing system
Publication Date: 2023.10.18 ALPINE ELECTRONICS INC
  • EP3926444B1 patent drawingFigure 1
  • EP3926444B1 patent drawingFigure 2
  • EP3926444B1 patent drawingFigure 3A~3B

AI summary

"A proximity detection device and an information processing system" which suppress omission of acceptance of an operation due to reflection by a user's wrist or arm are provided. When a right-moving gesture operation of moving the hand close to the display (2) from left to right in the display (2) is performed (a), the transition of the position where the hand returns to the left side due to the reflection by the wrist or the like may be detected (b). The detection control unit (323) which detects the approach of the hand to the display (2) and notifies the data processing device (1) of the position of the hand notifies the data processing device (1) of non-detection of hand approach at the time Pd when the amount of movement dx of the position of the hand to the right direction starts to decrease after exceeding the threshold value Th. The data processing device (1) calculates the amount of movement Δx to the right direction from the position xS when the detection of the approach of the hand is started until the position xPd-1 immediately before the time Pd when notification of the non-detection is provided, and accepts the right-moving gesture operation to perform a predetermined process when the amount of movement Δx exceeds the threshold value Th (d).