Optical Device Using Reflective Polarizing Plates and Rotators
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Solution Overview
Problem
Existing electronic devices, such as goggles-type and glasses-type devices, face challenges in achieving a thin, lightweight, and high-contrast display with low power consumption due to the use of half mirrors with low light utilization efficiency.
Innovation Solution
A thin optical device is designed using a configuration of a first reflective polarizing plate, a first lens, an optical rotator, a second reflective polarizing plate, and a second lens, which enhances light utilization efficiency by eliminating the need for a half mirror.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a half mirror is used in the optical device, then the device can be made thin with short focal length, but the light utilization efficiency is low
Solution Approach 1:
The patent removes the half mirror component from the optical system and replaces it with a combination of reflective polarizing plates and optical rotators. This extraction of the problematic half mirror eliminates the inherent light loss while maintaining the short focal length requirement for thin optical devices.
Solution Approach 2:
The patent changes the optical parameters by using reflective polarizing plates with specific polarization characteristics and optical rotators with controlled rotation angles. This parameter change allows for high light utilization efficiency while achieving the desired thin profile and short focal length.
2Loss of energy
If the luminance of the display apparatus is increased to compensate for low light utilization efficiency, then the light utilization can be improved, but the power consumption increases and reliability decreases
Solution Approach 1:
By removing the half mirror that causes light loss, the patent eliminates the need to increase display luminance to compensate for inefficiency. The new optical system inherently achieves high light utilization efficiency, thereby reducing power consumption without sacrificing light output.
Solution Approach 2:
The patent replaces the mechanical/optical half mirror system with a polarization-based optical system using reflective polarizing plates and optical rotators. This substitution fundamentally changes the light control mechanism to one that preserves light energy, reducing the need for high power consumption.
3Device complexity
If a half mirror is used in the optical device, then the device structure can be simplified, but the light utilization efficiency is low
Solution Approach 1:
The patent segments the optical system into distinct functional components: reflective polarizing plates for polarization control and optical rotators for rotation control. This segmentation replaces the single half mirror component with a coordinated system that, while having more parts, achieves superior light utilization efficiency through specialized functions of each component.
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 proposed optical device achieves high light utilization efficiency, enabling the development of small, thin, and low-power electronic devices with improved reliability and portability.
Implementation Method 1
The first reflective polarizing plate can transmit first linearly polarized light and can reflect second linearly polarized light that is orthogonal to the first linearly polarized light
Implementation Method 2
The optical rotator can rotate a polarization plane of the first linearly polarized light by 45°
Data Source
AI summary
A thin optical device having high light utilization efficiency and a small electronic device including the optical device are provided. The thin optical device includes a reflective polarizing plate, a lens, and an optical rotator. The optical device can be a thin optical device that is small in overall length by rotation of the polarization plane of linearly polarized light with the optical rotator and utilization of properties of transmitting and reflecting light of the reflective polarizing plate. Furthermore, the optical device does not use a half mirror; thus, the optical device has a property of high light utilization efficiency, and the power consumption of the electronic device can be reduced and the reliability of the electronic device can be improved.