Virtual Image Display Optics for High See-Through Transmittance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing virtual image display devices with liquid crystal panels suffer from reduced see-through transmittance near the center of the field of view, requiring larger optical systems to maintain higher transmittance, which increases device size.
Innovation Solution
A virtual image display device incorporating a segmented OLED panel with light emission and transparent regions, a display element with sub-pixels and transparent regions, a patterned half-waveplate with different polarization regions, and a polarization imaging optical system to manage light polarization and transmission, enabling simultaneous observation of virtual images and external light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If processing such as formation of dots and application of a scattering material is performed on the light emission region of the light guide plate, then the video light can be properly displayed, but the see-through transmittance near the center of the field of view is reduced
Solution Approach 1:
The light guide plate is divided into a light emission region and a light transmission region. The light emission region undergoes processing (dot formation, scattering material application) for video light display, while the light transmission region remains unprocessed to maintain high see-through transmittance. This segmentation allows different regions to serve different functions without compromising either video display quality or see-through performance.
Solution Approach 2:
Different regions of the light guide plate are given different optical properties. The light emission region has scattering properties for video light emission, while the light transmission region maintains high transparency for external light passage. This local differentiation of optical characteristics resolves the contradiction between video display quality and see-through transmittance.
2Illumination intensity
If an optical system with higher see-through transmittance is separately required, then see-through display with higher transmittance can be realized, but the device size increases
Solution Approach 1:
The light guide plate serves multiple functions: it guides backlight for video display in the light emission region and transmits external light for see-through display in the light transmission region. This multi-functionality eliminates the need for separate optical systems, achieving high see-through transmittance without increasing device size.
Solution Approach 2:
The video display function and see-through display function are merged into a single light guide plate structure. By combining these functions in one component with regionally differentiated properties, the device avoids the size increase that would result from adding a separate optical system for see-through display.
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
Enhances see-through transmittance by optimizing light polarization and transmission, allowing for compact device design without compromising image quality.
Implementation Method 1
a patterned half-waveplate having a first polarization region that faces the sub-pixel and has a first polarization characteristic selectively functioning with respect to a linearly-polarized light in a polarization direction parallel to a first axis direction and a second polarization region that faces the second transparent region and has a polarization characteristic different from that of the first polarization region
Data Source
AI summary
A virtual image display device includes a segmented OLED panel having a light emission region emitting a backlight and a first transparent region transmitting an external light, a display element having a pixel including a sub-pixel that faces the light emission region and transmits the backlight to emit a video light and a second transparent region that faces the first transparent region and transmits the external light, a patterned half-waveplate having a first polarization region that faces the sub-pixel and has a first polarization characteristic selectively functioning with respect to a linearly-polarized light in a polarization direction parallel to a first axis direction and a second polarization region that faces the second transparent region and has a polarization characteristic, and a polarization imaging optical system that faces the display element with the patterned half-waveplate in between, images the video light, and transmits the external light.