Collimated Light Guide Source for Uniform HUD Illumination
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Solution Overview
Problem
Existing light source devices using LEDs and collimators have insufficient light utilization efficiency and uniform illumination characteristics, making them unsuitable for miniaturized and efficient illumination in display devices like HUDs and aerial floating image displays.
Innovation Solution
A light source device incorporating a collimating optical system with a high-luminance LED and a light guide, along with a reflective film that reflects blue and ultraviolet light, and a polarization conversion element to align light polarization, enhancing light utilization efficiency and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional LED and collimator optical system is used, then the light source can be miniaturized, but the light utilization efficiency and uniform illumination characteristics are insufficient
Solution Approach 1:
The optical system is segmented into multiple functional components: collimator lens, light guide, reflective film, and polarization conversion element. Each component performs a specific function to optimize light utilization, with the reflective film capturing previously wasted light and the polarization element ensuring uniform illumination characteristics.
Solution Approach 2:
A light guide is introduced as an intermediary component between the collimator and the final illumination target. The light guide redirects and distributes light uniformly, while a reflective film acts as an intermediary to capture and redirect light that would otherwise be lost, improving overall light utilization efficiency.
2Volume of moving object
If a conventional LED and collimator optical system is used, then the light source can be miniaturized, but the uniform illumination characteristics are insufficient
Solution Approach 1:
A light guide is introduced as an intermediary component between the collimator and the final illumination target. The light guide redirects and distributes light uniformly, while a reflective film acts as an intermediary to capture and redirect light that would otherwise be lost, improving overall light utilization efficiency.
Solution Approach 2:
The polarization state of light is changed through the polarization conversion element, transforming the light properties to achieve uniform illumination characteristics. This parameter change in light polarization enables consistent illumination across the display surface.
3Device complexity
If blue light and ultraviolet light are not reflected, then the optical system is simpler, but light utilization efficiency is reduced
Solution Approach 1:
The reflective film converts what would be wasted blue and ultraviolet light into useful illumination by reflecting it back toward the light guide. This transforms potentially harmful or unused wavelengths into beneficial light that contributes to overall illumination efficiency.
Solution Approach 2:
Instead of discarding blue and ultraviolet light that would normally be lost, the reflective film recovers this light and redirects it back into the optical system through the light guide, improving overall light utilization efficiency without significantly increasing device complexity.
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 achieves a miniaturized, high-efficiency, and reliable light source device suitable for miniaturized display devices, with improved light utilization and uniform illumination characteristics.
Implementation Method 1
A reflective film is provided so as to have an optical characteristic of reflecting blue light and ultraviolet light to the LED side
Implementation Method 2
A polarization conversion element is provided to reflect a part of light emitted from the LED to the LED side by an action of the reflective film, and to align a polarization direction of light emitted from the light guide in one direction
Implementation Method 3
a collimating optical system configured to, by using a high-luminance light emitting diode (LED) as a solid-state light source, convert light emitted from the solid-state light source into substantially parallel light
Data Source
AI summary
A light source device which is miniaturized, can be manufactured at low cost, and is suitable as an illumination light source of a display device of an electronic device such as an HUD and an aerial floating image display apparatus is provided. The light source device includes: a light source configured to generate white light by irradiating a phosphor with light emitted from a solid-state light source; a collimating optical system (15) configured to convert a divergent light flux of the white light emitted from the light source into parallel light; a light guide configured to cause the light emitted from the collimating optical system (15) to be incident as incident light and emit the incident light in a direction different from an incident direction; and a filter configured to reflect light in a blue region of the parallel light to irradiate the phosphor.