Projector Illumination Architecture Using Blue-to-Green Conversion
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Solution Overview
Problem
Existing projector architectures face challenges in achieving high color gamut coverage with efficient use of green light, leading to either low color performance or high costs due to excessive green laser diode usage, and they also incur additional costs for resolving laser speckle issues.
Innovation Solution
A comprehensive optical architecture incorporating blue, green, and red laser modules along with a wavelength conversion component, which reduces the number of green light sources or their intensity while maintaining overall light intensity, achieving wide color gamut coverage at lower costs by integrating optical adjustments within the wavelength conversion component.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If an excitation light source, phosphor wheel, and filter wheel are used to generate different colors at different timings, then the architecture can produce yellow light by exciting phosphor, but color gamut coverage of visible light is low and green light is highly consumed
Solution Approach 1:
The patent segments the green light generation into two independent paths: a first green light source (laser diode) and a second green light source (phosphor conversion of blue light). This segmentation allows each path to contribute differently to the overall green light output, enabling better color gamut coverage while reducing excessive green light consumption by optimizing the contribution from each source.
Solution Approach 2:
The patent merges multiple light sources (first green light source, second green light source, red light source, blue light source) and combines their outputs through a light combining device. This merging approach integrates the advantages of different light generation methods to achieve superior color performance and wide color gamut coverage while maintaining efficient green light usage.
2Ease of manufacture
If red, green, and blue laser diode arrays are used to generate light in different colors at different timings, then color gamut coverage of visible light is high, but a large quantity of green LDs is used which is costly
Solution Approach 1:
The patent segments the green light generation into two independent paths: a first green light source (laser diode) and a second green light source (phosphor conversion of blue light). This segmentation reduces the quantity of green LDs needed while maintaining high color gamut coverage, as the phosphor-based path supplements the laser diode path.
Solution Approach 2:
The patent introduces a wavelength conversion component (phosphor wheel) as an intermediary to convert blue light to green light. This intermediary approach provides an alternative to direct green laser diode emission, reducing the quantity of green LDs required while maintaining color gamut coverage.
3Reliability
If a diffusion wheel is added to a laser path to resolve a laser speckle problem, then speckle issues are addressed, but the system becomes costly
Solution Approach 1:
The patent resolves laser speckle by introducing a rotating diffusion wheel that adds temporal and spatial dimensionality to the laser beam path. The rotation creates multiple slightly different beam paths that overlap, effectively reducing speckle patterns through dynamic averaging without requiring complex static diffusion structures.
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 solution enables projection devices to achieve high color gamut coverage with improved color performance and reduced costs by utilizing a comprehensive optical architecture that includes a wavelength conversion component, effectively managing green light sources and eliminating speckle issues.
Implementation Method 1
a wavelength conversion component (140), configured to convert the blue beam into a green beam
Implementation Method 2
a blue laser module (110), configured to emit a blue beam (BB) with a full width at half maximum (FWHM) of a light intensity spectrum being less than or equal to 25 nm
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2A~3
AI summary
The invention provides an illumination system (100), configured to provide an illumination beam (IB). The illumination system (100) includes blue (110), green (120), and red (130) laser modules respectively configured to provide blue (BB), green (GB), and red (RB) beams and a wavelength conversion component (140). The wavelength conversion component (140) includes a wavelength conversion region (WCR, 144) and an optical output region (OOR, 150). In a first time interval (T1), the blue, green, and red beams are sequentially transmitted to the optical output region (OOR, 150), where the illumination beam (IB) includes the blue, green, and red beams. In a second time interval (T2), the blue beam is transmitted to the wavelength conversion region (WCR, 144) to form a converted beam (CB), where the illumination beam (IB) includes the converted beam. A projection device (200) including the illumination system (100) is also provided. The projection device (200) using the illumination system (100) in the invention achieves color performance of a wide color gamut at relatively low costs.