Light Source Apparatus with Polarization Control for Outdoor Display
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Solution Overview
Problem
Conventional projection information display systems face inefficiencies in light utilization and power consumption when displaying images outside a vehicle or room, particularly due to wide diffusion angles of light sources and insufficient brightness under bright conditions.
Innovation Solution
A light source apparatus is configured with a point or surface light source, an optical element to reduce divergence, and a light guide body with a reflection surface, utilizing a reflection type polarization plate and retardation plate for polarization conversion, and a lenticular lens to control the divergence angle and enhance light directionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a wide diffusion angle light source is used for outdoor image display, then the light coverage area is improved, but the light utilization efficiency deteriorates
Solution Approach 1:
The patent applies local quality by providing different surface characteristics at different locations on the light guide body. The reflection surface has a specific roughness (Ra: 0.03μm to 0.3μm) that creates controlled scattering, while other surfaces maintain different properties. This localized surface treatment enables the light to spread coverage area while maintaining directional control and efficiency.
Solution Approach 2:
The patent changes the physical parameter of the reflection surface roughness to optimize light propagation. By controlling the surface roughness within a specific range (Ra: 0.03μm to 0.3μm), the system achieves improved light utilization efficiency while maintaining adequate coverage area for outdoor display applications.
2Device complexity
If conventional light sources are used without polarization control, then the device complexity is reduced, but the contrast ratio under bright conditions deteriorates
Solution Approach 1:
The patent introduces a polarization plate as an intermediary component between the light guide body and the image display apparatus. This polarization plate, combined with the controlled reflection surface, acts as a mediator that enhances contrast ratio by controlling light polarization states, thereby improving outdoor visibility without excessive complexity increase.
3Illumination intensity
If high power light sources are used to increase brightness for outdoor display, then the illumination intensity is improved, but the power consumption increases
Solution Approach 1:
The patent converts the potentially harmful effect of light loss into a beneficial outcome by using a reflection surface with optimized roughness. Instead of losing light at the reflection interface, the controlled scattering from the roughened surface redirects light efficiently, turning what would be wasted light into useful illumination, thereby achieving high brightness with lower power consumption.
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 configuration enables high-resolution image display with reduced power consumption by efficiently delivering light with a narrow diffusion angle and specific polarization, improving light utilization efficiency and contrast ratio, allowing for effective outdoor image projection.
Implementation Method 1
a reflection surface configured to reflect the light from the light source toward the reflection type polarization plate
Implementation Method 2
a reflection type polarization plate arranged between the light guide body and the image display apparatus, wherein light in a specific polarization direction reflected by the reflection type polarization plate
Implementation Method 3
the light is caused to pass a retardation plate twice, thereby performing polarization conversion
Data Source
AI summary
A light source apparatus configured to supply light in a specific polarization direction to an image display apparatus includes a point or surface light source, an optical unit configured to reduce a divergence angle of light from the light source, and a light guide body having a reflection surface configured to reflect the light from the light source and propagate it to the image display apparatus, the reflection surface of the light guide body is arranged so as to face the image display apparatus, and a reflection type polarization plate and a retardation plate are arranged in order from a side closer to the image display apparatus between the image display apparatus and the reflection surface.