Hybrid Lighting Device for Projectors Using Laser-Excited Fluorescence
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Solution Overview
Problem
Projectors using solid-state light sources face challenges with low luminous flux and efficiency, particularly with blue light emission, necessitating innovative solutions to enhance brightness and lifespan.
Innovation Solution
A lighting device configuration utilizing a combination of a laser-excited fluorescent light source and a light-emitting diode, with distinct light-converging optics and illumination optical systems, where the f-number for the light-emitting diode's beam is lower than that for the fluorescent light source's beam, to maximize light use efficiency and brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a solid-state light source (semiconductor laser or light-emitting diode) is used instead of a discharge lamp, then the lifespan and reliability are improved, but the luminous flux and brightness are reduced
Solution Approach 1:
The patent combines multiple light sources (semiconductor laser and light-emitting diode) with a fluorescent light source to create a hybrid illumination system. The semiconductor laser provides blue light that excites the fluorescent material to generate yellow light, while the light-emitting diode supplements the blue component, achieving high luminous flux comparable to discharge lamps while maintaining the long lifespan of solid-state sources.
Solution Approach 2:
The patent uses a fluorescent light source comprising a fluorescent material layer formed on a reflective film, creating a composite optical structure. This composite design enables efficient conversion of blue light to yellow light while maintaining high overall light output and color quality.
2Reliability
If a light-emitting diode is used for blue light to improve safety and lifespan, then the reliability is improved, but the light use efficiency is reduced due to large light-emitting surface area
Solution Approach 1:
The patent merges the light-emitting diode with the laser-excited fluorescent light source system. The light-emitting diode supplements the blue light component that is not sufficiently generated by the fluorescent conversion process, thereby improving overall light use efficiency while maintaining the safety advantages of solid-state light sources.
3Illumination intensity
If multiple light sources are combined to increase luminous flux, then the brightness is improved, but the device complexity increases
Solution Approach 1:
The patent combines multiple light sources and optical systems into a unified illumination device where the semiconductor laser, light-emitting diode, and fluorescent light source work together in an integrated manner, achieving high luminous flux without proportionally increasing device complexity.
4Use of energy by moving object
If a laser beam is used for blue color to improve light use efficiency, then the brightness is improved, but safety concerns arise due to coherent light
Solution Approach 1:
The patent uses the fluorescent material as an intermediary that converts the coherent blue laser beam into incoherent yellow light through fluorescent emission. This intermediary conversion process eliminates the safety hazards of coherent laser light while preserving the high light use efficiency benefits of laser excitation.
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 configuration results in a high-efficient lighting device that enhances the brightness and extends the lifespan of projectors while ensuring safety by converting laser beams into incoherent light, achieving high-definition and high-brightness projections with favorable color reproduction.
Implementation Method 1
Ultraviolet light from a light-emitting diode 1 is incident on a color wheel 2... By the ultraviolet light incident on the color wheel 2, red, green, and blue light is emitted
Implementation Method 2
first light-converging optics configured to converge light from the first light source into a first light beam
Implementation Method 3
an illumination optical system configured to make the first light beam and the second light beam into illumination light
Data Source
AI summary
A lighting device includes a first light source, a second light source of a light-emitting surface area larger than that of the first light source, first light-converging optics configured to converge light from the first light source into a first light beam, second light-converging optics configured to converge light from the second light source into a second light beam, and an illumination optical system configured to make the first light beam and the second light beam into illumination light, with a f-number of the illumination optical system for the second light beam being lower than a f-number of the illumination optical system for the first light beam.