Projection Device Polarizing Plate View-Through Balance

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Solution Overview

Problem

Conventional projection apparatuses with opaque screens hinder the view of the surroundings, while light transmissive reflectors used in head-up displays face challenges in balancing image density for safe driving, as too high density obstructs the view outside and too low density compromises driving information visibility.

Innovation Solution

A projection apparatus with a polarizing plate that absorbs and reflects output light, featuring an aromatic disazo compound, achieving a reflectance of 10% or more and single transmittance between 30% to 90%, allowing clear image display and sufficient view-through capability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a light transmissive reflector is used in a head-up display, then the driver can view both the projected image and the sight outside the vehicle, but the image density becomes difficult to balance - too high density obstructs the view outside while too low density compromises driving information visibility

Engineering Contradiction:
Improveviewing capabilityVSAvoidimage density
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent applies parameter changes by optimizing the reflectance and transmittance parameters of the polarizing plate. Specifically, the polarizing plate is designed with reflectance of 10% or more and single transmittance of 30% to 90%, creating an optimal balance between image visibility and outside view. This quantitative parameter optimization resolves the contradiction by finding the precise range where both viewing capability and image density requirements are satisfied simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If an opaque screen is used in a projection apparatus, then the projected image is clearly visible, but the observer cannot view the sight behind the screen through the projection apparatus

Engineering Contradiction:
Improveimage visibilityVSAvoidviewing capability
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent employs composite materials by combining the polarizing plate with specific optical properties into the projection apparatus. The polarizing plate acts as a composite optical element that simultaneously provides reflection for image projection and transmission for outside viewing. This composite structure resolves the contradiction by integrating multiple functions (image display and transparency) into a single component, enabling both clear image visibility and viewing capability behind the screen.

Inventive Principle:
Principle #40Composite materials

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

Enables clear projection of images while allowing sufficient view-through, optimizing image density for safe driving by using a polarizing plate with specific reflectance and transmittance properties to balance image clarity and visibility of surroundings.

Implementation Method 1

a polarizing plate including a polarizer irradiated with the output light, in the polarizing plate, an absorption axis is arranged to absorb and reflect the output light by the polarizing plate

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

reflectance of the polarizing plate for the output light is 10% or more

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3153895B1Projection device and vehicle
Publication Date: 2019.09.04 NITTO DENKO CORP
  • EP3153895B1 patent drawingFigure 1(a)~1(b)
  • EP3153895B1 patent drawingFigure 2~3
  • EP3153895B1 patent drawingFigure 4(a)~4(b)

AI summary

The present invention provides a projection apparatus capable of clearly displaying a projected image, and allowing the sight behind the projected image to be viewed to a sufficient degree. A projection apparatus 1 of the present invention includes a light irradiation device 3 configured to emit an output light 2 having one polarized light component, and a polarizing plate 4 including a polarizer 41 irradiated with the output light 2, wherein in the polarizing plate 4, an absorption axis is arranged to absorb and reflect the output light 2 by the polarizing plate, reflectance of the polarizing plate 4 for the output light 2 is 10% or more, and single transmittance of the polarizing plate 4 is in the range of 30% to 90%.