Conjugate Illumination System for LCD Projectors
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Solution Overview
Problem
Conventional LCD projectors suffer from significant lighting loss due to low polarization efficiency, leading to inefficiencies in energy usage, heat dissipation, and increased costs, with existing pseudo-technologies offering little to no improvement.
Innovation Solution
A conjugate illumination system for LCD projectors comprising an LED light source, square cone condenser, collimating lens, quarter-wave plate, brightness-enhancing polarizer, LCD light valve, field lens, and projection lens, where the light-transmitting surface of the square cone condenser is bisected to form sub-surfaces for optical conjugation of the LED light source and reflector, allowing for efficient separation and reuse of polarized light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If natural light is used to illuminate the LCD light valve, then the projector can be manufactured with simple structure and low cost, but over 50% of the light energy is filtered by the polarizer resulting in low lighting efficiency and high energy loss
Solution Approach 1:
The patent recovers the polarized light that would otherwise be discarded by the polarizer. The reflector redirects the reflected light back through the LCD light valve, allowing the same light energy to be utilized multiple times. This transforms a single-pass system into a multi-pass system, significantly improving lighting efficiency without requiring complex additional optical components
Solution Approach 2:
The patent implements continuous utilization of light energy by circulating it through the system. The reflector enables the light to pass through the LCD light valve multiple times in succession, maintaining useful action rather than allowing the light to be wasted after a single pass. This continuous action approach maximizes the extraction of useful work from each photon
2Reliability
If the polarizer filters natural light to create linearly polarized light, then the LCD light valve can function properly, but 38%-45% polarization efficiency results in 55%-62% energy loss and increased heat dissipation
Solution Approach 1:
Instead of discarding the light energy filtered by the polarizer, the system recovers it using the reflector. The reflected light is redirected back through the LCD light valve, allowing the same energy to perform useful work again. This recovery mechanism dramatically reduces the effective energy loss that would otherwise occur at the polarizer
Solution Approach 2:
The patent converts the harmful reflected light (which normally represents wasted energy and heat) into a beneficial resource. By using the reflector to redirect this light back through the system, the previously harmful reflected portion becomes useful illumination, effectively turning waste into value and reducing overall energy consumption
3Ease of manufacture
If conventional polarization systems are used, then the optical system can be manufactured with simple structure, but the heat dissipation burden increases fundamentally limiting performance
Solution Approach 1:
The patent converts the harmful heat-generating reflected light into a beneficial resource by redirecting it back through the LCD light valve via the reflector. This approach reduces the net energy that must be dissipated as heat, lowering the thermal burden on the system while maintaining manufacturing simplicity
Solution Approach 2:
The system recovers the energy that would otherwise be lost as heat through the polarizer. By redirecting this energy back through the optical path, the system extracts additional useful work from it before final dissipation, effectively reducing the total heat generation and improving thermal management
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 system significantly enhances lighting efficiency, reduces power consumption, minimizes projector volume and noise, and lowers production costs by effectively recycling polarized light that would otherwise be lost, resulting in improved performance and user experience.
Implementation Method 1
a quarter-wave plate (4)... the quarter-wave plate (4), focusing by the collimating lens (3)... passing the reflected light through the quarter wave plate (4) twice, and rotating polarization plane by 90°
Implementation Method 2
a brightness-enhancing polarizer (5)... the brightness-enhancing polarizer (5) transmits the linearly polarized light required by the LCD light valve (6)... the brightness-enhancing polarizer (5) reflects linearly polarized light orthogonal to the polarization plane
Implementation Method 3
a collimating lens (3)... the collimating lens (3)... collimated by the collimating lens (3)
Implementation Method 4
a square cone condenser (2)... the square cone condenser (2)... collecting by the square cone condenser (2)
Implementation Method 5
a reflecting mirror (9)... the reflector (9)... reflecting by the reflecting mirror (9), then being collected by the square cone condenser (2)
Implementation Method 6
since the transmissive single LCD projector is based on illuminating its liquid crystal molecules with online polarized light, bright and dark images are generated through an analyzer
Data Source
AI summary
An efficient conjugate lighting system for an LCD projector, includes an LED light source, a square cone condenser, a collimating lens, a quarter-wave plate, a brightness-enhancing polarizer, an LCD light valve, a field lens and a projection lens which are provided in sequence according to a direction of light travel; wherein the efficient conjugate lighting system for the LCD projector further comprises a reflecting mirror provided at an entrance port of the square cone condenser; a light-transmitting surface of the entrance port of the square cone condenser is bisected along a horizontal centerline or a vertical centerline to form a first sub-light-transmitting surface and a second sub-light-transmitting surface; a light-emitting surface of the LED light source is provided on the first sub-light-transmitting surface, and the reflector is provided on the second sub-light-transmitting surface.