Cholesteric LCD Projection Apparatus Light Utilization
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Solution Overview
Problem
In liquid crystal display (LCD) projectors, the use of color filters results in low light transmittance and utilization rates, and the polarizer further reduces light efficiency, leading to increased panel temperatures and performance issues under high brightness light sources.
Innovation Solution
A projection apparatus utilizing a liquid crystal display panel with cholesteric liquid crystals in a conical helix texture, which reflects light based on helix pitch, eliminating the need for a color filter and enhancing light utilization by adjusting the helix pitch to control color and reflectivity, combined with optical components like Fresnel lenses to optimize light propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If color filters are used in LCD projectors to achieve color display, then color gamut is improved, but light transmittance and utilization rate deteriorate
Solution Approach 1:
The patent extracts and removes the color filter component from the LCD projector system. Instead of using traditional color filters to achieve color display, the invention uses a reflective LCD panel that reflects ambient light or light from a backlight unit, eliminating the need for color filters and thereby significantly improving light utilization rate while maintaining color gamut performance
Solution Approach 2:
The patent changes the operating principle of the LCD panel from transmission mode to reflection mode. By changing the physical state and optical properties of the LCD panel (using reflective polarizing plates and specific liquid crystal alignment), the system achieves color display without absorbing light through color filters, thus resolving the contradiction between color gamut and light utilization
2Illumination intensity
If polarizer is used to control light in LCD projectors, then display quality is improved, but light efficiency deteriorates
Solution Approach 1:
The patent merges the functions of the polarizer and the reflective LCD panel into a unified system. The reflective polarizing plates serve dual purposes: controlling the polarization state of light for display quality and reflecting light back through the LCD panel to improve overall light efficiency. This integration reduces the number of separate optical components and minimizes light loss
Solution Approach 2:
The patent implements a light recycling mechanism where light that passes through the LCD panel is reflected back by the reflective polarizing plates and passes through the panel again. This continuous action of light traversing the display medium multiple times improves both display quality and light efficiency, as the same light energy is utilized repeatedly rather than being discarded after a single pass
3Illumination intensity
If high brightness light sources are used to improve illumination, then display brightness is improved, but panel temperature increases causing performance issues
Solution Approach 1:
The patent converts the harmful effect of high light intensity (heat generation) into a beneficial effect by using reflective polarizing plates that redirect light back through the LCD panel. This allows the use of high brightness light sources while maintaining lower panel temperatures, as the reflected light path distributes heat more evenly and allows for better thermal management. The system achieves high display brightness without proportionally high panel temperatures
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
Achieves high color gamut display without a color filter and maintains a high light utilization rate, improving projector efficiency and reducing heat-related performance issues.
Implementation Method 1
the liquid crystal layer including cholesteric liquid crystals, and the cholesteric liquid crystals being configured to be in a conical helix texture under an electric field applied, so as to reflect light matched with a helix pitch of the conical helix texture
Implementation Method 2
reflect light matched with a helix pitch of the conical helix texture
Implementation Method 3
an optical component between the light emitting component and the liquid crystal display panel, and configured to adjust a propagation direction of light
Implementation Method 4
optical component... configured to adjust a propagation direction of light
Implementation Method 5
a first light focusing component, the first light focusing component is between the light emitting component and the collimating and light-extracting component, and is configured to focus the light irradiated to the first light focusing component to the collimating and light-extracting component
Data Source
AI summary
There is provided a projection apparatus, including: a light emitting component configured to generate light; a liquid crystal display panel on a light outgoing side of the light emitting component and including a liquid crystal layer between a first substrate and a second substrate, the liquid crystal layer including cholesteric liquid crystals configured to be in a conical helix texture under an electric field applied, so as to reflect light matched with a helix pitch of the conical helix texture; an optical component between the light emitting component and the liquid crystal display panel, and configured to adjust a propagation direction of light, an acute angle being formed between an optical axis of the optical component and a normal of the liquid crystal display panel; and a projection lens configured to receive and project the light reflected by the liquid crystal display panel. A display system is further provided.