Conductive Gear Rod Positioning for Rear View Displays

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Solution Overview

Problem

Existing rear view display positioning systems for vehicles are costly due to the use of separate potentiometers for detecting the orientation of the cover plate and have complex mechanical structures that prevent their use in state-of-the-art rearview devices.

Innovation Solution

A positioning system that uses conductive gear rods and a conductive spring jack to sense the position of the cover plate without separate potentiometers, employing constant voltage or current to determine the position through varying resistance values, allowing for a simpler and cheaper solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate potentiometers are used for detecting the orientation of the cover plate, then position detection accuracy is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveposition detection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the position detection function into the existing conductive gear rods and spring jack structure. The spring jack serves dual purposes: mechanically positioning the cover plate and electrically sensing its position through varying resistance values, eliminating the need for separate potentiometer components while maintaining detection accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The conductive spring jack and gear rods perform multiple functions simultaneously: they provide mechanical support for positioning the cover plate, enable electrical connectivity, and serve as position sensing elements through their varying resistance characteristics. This multi-functionality reduces overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If separate potentiometers are used for detecting the orientation of the cover plate, then position detection accuracy is improved, but manufacturing cost increases

Engineering Contradiction:
Improveposition detection accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent combines position detection functionality with existing conductive components (gear rods and spring jack), eliminating the need for separate potentiometer assemblies. This integration reduces part count, simplifies manufacturing processes, and lowers overall system cost while maintaining detection precision through resistance-based sensing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The conductive spring jack and gear rods inherently provide position detection capability through their own resistance properties. The system uses the existing mechanical components' electrical characteristics for sensing, eliminating the need for additional dedicated sensing components and reducing manufacturing complexity.

Inventive Principle:
Principle #25Self-service

3Device complexity

If a mechanical structure without potentiometers is used, then device complexity is reduced, but measurement capability is lost

Engineering Contradiction:
Improvesystem simplicityVSAvoidposition sensing capability
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the traditional mechanical potentiometer sensing mechanism with an electrical resistance-based sensing approach. The position of the cover plate is detected by measuring the varying resistance values in the conductive spring jack and gear rod connections, substituting mechanical contact-based sensing with electrical field-based measurement.

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

Solution Approach 2:

The system detects position changes by monitoring variations in electrical resistance parameters of the conductive spring jack and gear rods. As the cover plate orientation changes, the contact points and resistance values change, providing continuous position information without mechanical potentiometers.

Inventive Principle:
Principle #35Parameter changes

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 approach reduces the need for potentiometers, resulting in a more stable, durable, and cost-effective positioning system that maintains the advantages of traditional systems while being smaller and lighter, with improved precision and reduced maintenance.

Implementation Method 1

a spring jack (40) comprising conductive material, wherein the spring jack is adapted to contact the first gear rod (20) and the second gear rod (30); and position sensing means adapted to sense the position of the first gear rod (20) relative to the spring jack (40) with at least a first resistance value of a first conductive path between at least a first point on the first gear rod (20) and the spring jack (40) varying with the position of the first gear rod (20) relative to the spring jack (40)

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3261880B1Positioning system for a rear view display device
Publication Date: 2019.01.02 SMR PATENTS S A R L
  • EP3261880B1 patent drawingFigure 1a~1b
  • EP3261880B1 patent drawingFigure 2a~2b
  • EP3261880B1 patent drawingFigure 3

AI summary

The present invention relates to a positioning system (10, 10') for a rear view display device comprising at least a first gear rod (20, 20') for positioning a cover plate (50, 50'), wherein the first gear rod (20, 20') comprises conductive material, and second gear rod (30, 30') for positioning the cover plate (50, 50'), wherein the second gear rod (30, 30') comprises conductive material; a spring jack (40, 40') comprising conductive material, wherein the spring jack (40, 40') is adapted to contact the first gear rod (20, 20') and the second gear rod (30, 30'); and position sensing means adapted to sense the position of the first gear rod (20, 20') relative to the spring jack (40, 40') with at least a first resistance value of a first conductive path between at least a first point on the first gear rod (20, 20') and the spring jack (40, 40') varying with the position of the first gear rod (20, 20') relative to the spring jack (40, 40'). The invention also relates to a rear view display for a vehicle comprising such a positioning system (10, 10'), and to a vehicle comprising such a rear view display.