Transparent Display Device with Simplified Polarization Control
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Solution Overview
Problem
The existing transparent liquid crystal display devices have a complex configuration due to the liquid crystal panel being disposed between two polarizers and a prism arranged between the liquid crystal panel and the light guide plate, which results in a background not being clearly visible from the front side.
Innovation Solution
A display device with a simplified configuration that includes a first illuminant/ambient light adjusting unit, a polarized illumination unit, and polarized component separating units to modulate and transmit polarized light, allowing the background to be seen through by controlling the polarization directions of ambient and illumination light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a liquid crystal panel is disposed between two polarizers to achieve transparent display, then the display can show images, but the configuration becomes complicated
Solution Approach 1:
The patent removes one polarizer from the traditional two-polarizer liquid crystal display configuration. By extracting the unnecessary polarizer and using a reflective polarizing film on the light guide plate, the configuration is simplified while maintaining the transparent display functionality. This reduces the number of optical layers and simplifies the overall device structure.
Solution Approach 2:
The patent inverts the traditional transmission-type polarizing arrangement by using a reflective polarizing film. Instead of transmitting polarized light through multiple layers, the reflective film reflects polarized light back through the liquid crystal panel, achieving the same display effect with fewer components and improved optical efficiency.
2Illumination intensity
If a prism and light reflective sheet are arranged between the liquid crystal panel and light guide plate to change light direction, then light can be directed to the normal direction, but the background becomes unclear and visibility is reduced
Solution Approach 1:
The patent removes the prism and light reflective sheet from the optical path between the liquid crystal panel and light guide plate. By extracting these components, the optical path is simplified and background visibility is restored. The light direction control is achieved instead through the reflective polarizing film and optimized light guide plate structure.
3Ease of manufacture
If multiple optical components are arranged to modulate light polarization, then image display is achieved, but the number of components increases and device complexity increases
Solution Approach 1:
The patent merges the functions of multiple optical components into fewer integrated elements. The reflective polarizing film combines polarization and reflection functions, while the light guide plate integrates light distribution and structural support functions. This merging reduces the total number of components and simplifies the optical system architecture.
Solution Approach 2:
The light guide plate is designed to perform multiple functions simultaneously: it guides illumination light, reflects polarized light, and provides structural support. This multi-functionality reduces the need for separate dedicated components, simplifying the overall device configuration while maintaining effective light modulation and display performance.
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 display device achieves clear visibility of the background while displaying images, with improved transparency and reduced glare, and can switch between displaying images and showing only the background, similar to organic EL displays.
Implementation Method 1
a first illuminant/ambient light adjusting unit that is configured of a pixel array having a plurality of pixels arranged therein and modulates a polarization direction of incident light for each of the pixels and transmits the incident light to the front side in a case where a voltage corresponding to an externally provided image signal is applied
Implementation Method 2
a polarized illumination unit that is arranged on a rear surface of the first illuminant/ambient light adjusting unit, transmits ambient light incident from a rear side thereof toward the first illuminant/ambient light adjusting unit, and emits polarized illumination light, of illuminant light emitted from an illuminant, including a specific polarization direction toward the first illuminant/ambient light adjusting unit
Implementation Method 3
a first polarized component separating unit that is arranged on a front surface of the first illuminant/ambient light adjusting unit and transmits at least any of the ambient light and the polarized illumination light having a polarization direction in the same direction as a transmission axis thereof to the front side in a case where at least any of the ambient light and the polarized illumination light is incident
Data Source
AI summary
Provided is a display device that can be realized with a simple configuration and functions as a transparent display allowing background to be clearly seen therethrough. When a liquid crystal panel is in an ON state, polarized backlight that is incident from a polarized backlight unit reaches a front surface. At this point, ambient light that is incident from a rear side also reaches the front surface. Accordingly, an observer who is on a front side of a transparent display can visually recognize an image that is displayed in an overlaid manner on the background seen through the transparent display. In a case where the liquid crystal panel is placed into an OFF state, the polarized backlight cannot reach the front surface of the transparent display, and the ambient light reaches the front surface.