Head-Up Display Diffuser Film Shift Detection for Laser Eye Safety

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Solution Overview

Problem

The position shift of the diffuser film in a head-up display can cause laser light to be directly emitted into the driver's eyes, posing a safety risk due to the inability to detect and prevent such shifts effectively.

Innovation Solution

A detection apparatus comprising a power supply, conductive module, and detection module forms a closed loop with the diffuser film, detecting when the loop opens due to film shift, triggering a control module to turn off the laser light source to prevent direct emission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the diffuser film is used to scatter laser light, then the light is safely projected onto the windshield, but the diffuser film may shift position causing laser light to be directly emitted into the driver's eyes

Engineering Contradiction:
Improvesafety of laser light projectionVSAvoiddirect laser emission into driver's eyes
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by detecting the diffuser film position before laser light projection occurs. The detection module continuously monitors the film position and triggers an alarm or shuts down the laser source before harmful direct emission can occur, preventing the hazard rather than responding to it after occurrence.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using the detection module to continuously monitor the diffuser film position and provide real-time information to the control system. When the film shifts from its correct position, the feedback signal triggers the alarm module or shuts down the laser source, creating a closed-loop safety system that responds to position changes.

Inventive Principle:
Principle #23Feedback

2Reliability

If a detection system is added to monitor diffuser film position, then safety is improved, but the device complexity increases

Engineering Contradiction:
Improvesafety monitoring capabilityVSAvoidnumber of detection components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses an intermediary approach by introducing a detection module that indirectly monitors the diffuser film position through detecting light transmission changes or electrical signals from conductive elements on the film. This intermediary detection method provides safety monitoring without requiring direct physical contact or complex mechanical sensors on the film itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies self-service by designing the detection system to utilize the diffuser film's own properties (such as its transparency or integrated conductive elements) for detection purposes. The film essentially detects its own position state through its interaction with light or electrical fields, reducing the need for separate active sensing components.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4113192B1Head-up display with apparatus for detecting shift of diffusion film
Publication Date: 2025.06.25 YINWANG INTELLIGENT TECHNOLOGIES CO LTD
  • EP4113192B1 patent drawingFigure 1
  • EP4113192B1 patent drawingFigure 2~3
  • EP4113192B1 patent drawingFigure 4

AI summary

An apparatus for detecting a shift of a diffuser film and a head-up display are provided, to detect the shift of the diffuser film, and are applied to the automatic driving field. The apparatus for detecting a shift of a diffuser film includes: a power supply (100), a conductive module (200), and a detection module (300). A relatively fixed position relationship exists between the conductive module (200) and the diffuser film. When the diffuser film is in a first position, the conductive module (200) is connected to the power supply (100) to form a closed loop. When the diffuser film is shifted from the first position to a second position, the closed loop is opened. Based on that the detection module (300) detects that the closed loop is opened, it may be determined that the diffuser film is shifted, so as to remind a user in time.