Vehicle Display Rear Pointer Light Source Positioning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing motor vehicle speedometer displays face issues with light loss and reduced readability, especially under sunlight or street lighting conditions, due to decoupling of light into the rear pointer, leading to insufficient visibility of displayed values.

Innovation Solution

A display device design where the light source is positioned at the outer end of the rear pointer, radiating into an optical element that creates a contoured light spot on the display surface, minimizing light losses and ensuring improved readability by eliminating the need for a movable mirror arrangement and allowing for variable light spot shaping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If light is decoupled into the rear pointer using a stationary laser cannon and pivoted mirror, then the target value marking can be displayed, but light loss occurs and readability is insufficient especially under sunlight or street lighting

Engineering Contradiction:
ImprovereadabilityVSAvoidlight loss
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent extracts the light source from the traditional decoupling mechanism and positions it directly at the outer end of the rear pointer. This eliminates the need for light to be decoupled through complex optical paths involving stationary laser cannons and pivoted mirrors, thereby reducing light loss and improving readability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an optical element as an intermediary between the light source and the display surface. This optical element shapes the light into a contoured light spot that is projected onto the display surface, improving the visibility and readability of the displayed value while minimizing light loss.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a movable mirror arrangement is used to deflect laser beam into predetermined position, then target value marking can be displayed, but device complexity increases

Engineering Contradiction:
Improvedisplay functionalityVSAvoidmovable mirror arrangement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent removes the movable mirror arrangement from the system entirely. Instead of using a complex mechanism to deflect laser beams, the light source is directly positioned at the rear pointer's outer end, and an optical element shapes the light into the desired contoured spot pattern, greatly simplifying the device structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical movable mirror system with a stationary optical element that shapes light directly. This substitution eliminates moving parts and complex mechanical arrangements while achieving the same display functionality through optical means.

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

3Illumination intensity

If light source is positioned at outer end of rear pointer radiating into optical element, then readability is significantly improved with minimum light losses, but additional optical components are required

Engineering Contradiction:
ImprovereadabilityVSAvoidoptical element
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent applies local quality by positioning the light source specifically at the outer end of the rear pointer where it is most needed for displaying the displayed value. The optical element is strategically placed to shape light only in the specific region where the contoured light spot is required, optimizing readability without unnecessary complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The optical element serves multiple functions: it shapes the light into a contoured spot, directs the light onto the display surface, and maintains the structural integrity of the pointer assembly. This multi-functionality reduces the need for additional separate components.

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

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 design enhances readability and maintains independence of the pointer shape from the light spot, providing clear and unambiguous representation of both driving speed and set speed values under various environmental conditions with reduced effort and cost.

Implementation Method 1

the light source is arranged on the rear pointer at its outer end section and radiates into an optical element of the display device

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 2

which delimits a contoured light spot displayed on the display surface

Methodology Applied
Scientific EffectOptical beam shaping: Lens

Data Source

PatentEP1880890B1Display device
Publication Date: 2009.10.07 ROBERT BOSCH GMBH
  • EP1880890B1 patent drawingFigure 1
  • EP1880890B1 patent drawingFigure 2
  • EP1880890B1 patent drawingFigure 3~4

AI summary

The invention relates to a display device (1) for a motor vehicle with two pointers (2, 3) arranged to pivot in parallel planes, to which a common dial (4) is assigned. For this purpose, the rear pointer (3) is at least partially covered by the circular dial (4) and is therefore only visible to the viewer in the area of ​​an annular display surface (5). To display a contoured light spot (6) designed as a light symbol, the rear pointer (3) has a light source (8) at its outer end section (7), which shines onto a light guide element (9) connected to the display surface (5) from the rear. Further light sources (10) can serve for the background illumination of the display surface (5).