Polarization Element Dichroic Mirror Optical Unit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical units and display devices using dichroic mirrors face challenges in reflecting and transmitting light from organic electroluminescent panels, as they are incident angle dependent and rely solely on transmittance-wavelength characteristics, leading to narrowed wavelength regions and reduced effective luminous flux for image display.
Innovation Solution
Incorporating a polarization element in the optical path from light-emitting elements to the dichroic prism, allowing reflection and transmission based on polarization direction, and utilizing dichroic mirrors with polarization separation characteristics to manage oblique light and maintain a wide wavelength region for image light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dichroic mirrors are used for reflection and transmission of light from organic electroluminescent panels, then color image synthesis is achieved, but the wavelength region is narrowed and effective luminous flux is reduced due to incident angle dependence
Solution Approach 1:
A polarization separation element is introduced as an intermediary between the light emitting element and the dichroic mirror. This element converts unpolarized light into polarized light with a specific polarization direction, enabling the dichroic mirror to effectively reflect and transmit light across a wider wavelength region without significant loss of luminous flux.
2Device complexity
If dichroic mirrors rely solely on transmittance-wavelength characteristics, then simple structure is maintained, but reflection and transmission cannot be appropriately performed over wide wavelength region when oblique light is present
Solution Approach 1:
The invention changes the parameter of light polarization state from unpolarized to polarized. By introducing a polarization separation element that outputs light with a specific polarization direction (e.g., s-polarized light), the system enables the dichroic mirror to maintain high reflection and transmission performance across a wide wavelength region even when handling oblique light.
3Measurement precision
If wavelength region of each color light is narrowed to widen intervals between wavelength regions, then dichroic mirror performance is improved, but effective luminous flux for image display is significantly reduced
Solution Approach 1:
The polarization separation element acts as a mediator that prepares light in a specific polarization state before it reaches the dichroic mirror. This enables the dichroic mirror to achieve effective wavelength separation across wide wavelength regions without needing to narrow the wavelength bands, thereby preserving the effective luminous flux.
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 approach enables high-quality image display without narrowing the wavelength region or reducing the effective luminous flux, even when light is significantly inclined or the dichroic mirror is incident angle dependent, thereby improving the efficiency and quality of color image synthesis.
Implementation Method 1
a polarization element that allows, of first polarized light and second polarized light having different polarization directions, the first polarized light to pass through, is arranged in an optical path from at least one of light-emitting elements
Implementation Method 2
at least one of the first dichroic mirror and the second dichroic mirror has polarization separation characteristics
Implementation Method 3
dichroic mirror is incident angle dependent... transmittance-wavelength characteristics
Implementation Method 4
the first dichroic mirror reflects the first image light toward the emission surface and allows the second image light and the third image light to pass through
Implementation Method 5
the second dichroic mirror reflects the second image light toward the emission surface and allows the first image light and the third image light to pass through
Data Source
AI summary
Provided are an optical unit and a display device that can appropriately perform reflection and transmission of image light emitted from a panel provided with a light emitting element, over a wide wavelength region in a dichroic mirror. The optical unit includes a first panel, a second panel, and a third panel arranged facing a first incident surface, a second incident surface, and a third incident surface of a dichroic prism, respectively, and each of the first panel, the second panel, and the third panel emits unpolarized image light. A polarization element is arranged between the first panel and the dichroic prism, and first image light emitted from the first panel is incident on the dichroic prism as linearly polarized light. A first dichroic mirror has polarization separation characteristics in addition to transmittance-wavelength characteristics.