Vehicle HUD Cam-Driven Mirror Adjustment

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Solution Overview

Problem

Existing vehicle display devices face challenges in reconciling rapid tilting for solar protection with precise adjustment to driver specifics, often resulting in increased device size, noise, and mechanical malfunctions due to complex transmission chains and intermediate parts.

Innovation Solution

A direct drive mechanism using a cam with a segment of increasing radius for mirror adjustment, combined with a return spring for stiffness and noise reduction, and a secondary means for rapid tilting, minimizing intermediate parts and noise pollution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a complex transmission chain with intermediate parts (gears, pins) is used to drive the mirror, then the mirror can be positioned accurately, but the device size increases, noise increases, and mechanical malfunctions occur more frequently

Engineering Contradiction:
Improvemirror positioning precisionVSAvoidtransmission chain complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent removes intermediate transmission components (gears, pins, belts) from the drive system. The motor directly drives the mirror through a simplified connection, extracting unnecessary complex parts while maintaining positioning precision through direct motor-mirror coupling.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a motor with reduction gear to amplify torque, the patent inverts the approach by using a high-torque motor without reduction gear, directly driving the mirror. This eliminates the need for intermediate transmission parts while maintaining both precision and torque requirements.

Inventive Principle:
Principle #13The other way round (Inversion)

2Speed

If a rapid tilting mechanism is used for solar protection, then the mirror can be cleared quickly, but the precision adjustment capability is compromised

Engineering Contradiction:
Improvemirror tilting speedVSAvoidmirror orientation precision
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent implements dynamic control of the mirror drive system. The motor can operate at different speeds depending on the required action: high speed for rapid clearing/solar protection, and low speed for precise positioning. This dynamic speed adjustment resolves the contradiction between speed and precision.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mirror operation follows periodic action patterns: rapid movement phases for clearing/solar protection alternate with slow, precise adjustment phases for positioning. This periodic variation in speed allows the system to achieve both rapid response and precise control at different times in the operation cycle.

Inventive Principle:
Principle #19Periodic action

3Reliability

If intermediate parts and transmission chains are used, then the mirror can be driven reliably, but wear, angular play, slippage and malfunctions increase

Engineering Contradiction:
Improvemirror drive reliabilityVSAvoidmechanical wear and slippage
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes intermediate transmission components (gears, pins, belts, couplings) that are sources of wear, slippage, and malfunction. The direct-drive architecture eliminates these harmful elements while maintaining reliable mirror positioning through the motor's direct connection to the mirror.

Inventive Principle:
Principle #2Taking out (Extraction)

4Area of stationary object

If the device footprint is reduced by positioning control organs behind the mirror, then the overall size decreases, but access for maintenance and assembly becomes difficult

Engineering Contradiction:
Improvedevice footprintVSAvoidassembly and maintenance accessibility
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The patent segments the control system into modular components that can be accessed independently. The direct-drive motor and control organs are positioned to allow modular access, maintaining a compact footprint while enabling easier assembly and maintenance through strategic component placement and accessibility design.

Inventive Principle:
Principle #1Segmentation

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

The solution provides precise adjustment and rapid tilting while reducing noise and mechanical issues, ensuring effective solar protection and driver information display without compromising acoustic comfort.

Implementation Method 1

a motor that directly drives a cam (4) having a segment of increasing radius for adjusting the orientation of the mirror (1) in the active position, the peripheral surface of the cam coming into sliding contact with the surface of the mirror or a lateral support extending said mirror

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

a spring for returning the mirror (1) against the surface of the cam (4)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

a spring for returning the mirror against the surface of the cam

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 4

a mirror for reflecting the display light

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3512734B1Adjustable head-up display device for a vehicle
Publication Date: 2022.05.04 MMT AG
  • EP3512734B1 patent drawingFigure 1
  • EP3512734B1 patent drawingFigure 2
  • EP3512734B1 patent drawingFigure 3

AI summary

The present invention relates to a display device for vehicles, which comprises a projection element emitting display light and a mirror (1) intended to reflect the display light, said mirror (1) being driven by a drive means intended for its angular displacement. Said drive means is formed by a motor (3) that directly drives a cam (4) having a segment of increasing radius for adjusting the orientation of the mirror (1) in the active position, the peripheral surface of the cam (4) coming into sliding contact against the surface of the mirror (1) or of a lateral stop extending said mirror (1).