Light Source Unit Time-Division Luminance
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Solution Overview
Problem
Existing projection apparatuses face challenges in achieving sufficient luminance due to low luminous efficiency, particularly in forming colors using a single light source or fluorescent light, which limits the brightness of projected images.
Innovation Solution
A light source unit comprising a first and second light emitting elements, a luminescent wheel with fluorescent regions emitting different wavelength bands, and a color wheel with specific transmissive regions, synchronized to emit light in a time division manner to enhance luminance and color reproduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single light source or fluorescent light is used to form colors, then the device complexity is reduced, but the luminance and brightness of projected images deteriorate due to low luminous efficiency
Solution Approach 1:
The light source unit is segmented into multiple independent light emitting elements (first light emitting element for first wavelength band, second light emitting element for second wavelength band) instead of using a single light source. This segmentation allows each element to be optimized for specific wavelength bands, improving overall luminous efficiency and luminance while maintaining manageable device complexity through modular design
Solution Approach 2:
The patent introduces a temporal dimension by sequentially controlling different light emitting elements to emit light in different time periods (first light emitting element in first output period, second light emitting element in second output period). This time-division multiplexing approach allows multiple light sources to function without simultaneously increasing spatial complexity, thereby improving luminance through cumulative light output while maintaining simple device structure
2Device complexity
If fluorescent light is used to generate color, then the device complexity is reduced, but the color reproducibility deteriorates due to limited wavelength bands
Solution Approach 1:
The color generation system is segmented into multiple specialized components: first light emitting element for first wavelength band, second light emitting element for second wavelength band, luminescent wheel with first fluorescent light emitting region for third wavelength band and second fluorescent light emitting region for fourth wavelength band. This segmentation enables precise control over wavelength bands, achieving superior color reproduction by combining light from multiple discrete spectral regions
Solution Approach 2:
The patent adds temporal sequencing to color generation by controlling different light emitting elements and fluorescent regions to operate in different time periods (first output period, second output period). This time-based dimension allows the system to synthesize full-color output by sequentially presenting different wavelength bands, achieving versatile color reproduction without requiring all components to operate simultaneously, thus managing device complexity effectively
3Device complexity
If a single light source emits all colors, then the device complexity is reduced, but the luminance in specific color periods deteriorates due to energy distribution across all colors
Solution Approach 1:
The light emission function is segmented into dedicated components for different wavelength bands (first light emitting element, second light emitting element, first fluorescent light emitting region, second fluorescent light emitting region). This segmentation concentrates energy into specific wavelength bands during their respective time periods, maximizing luminance in each color period rather than distributing energy across all colors simultaneously, while the modular structure keeps device complexity manageable
Solution Approach 2:
The patent introduces temporal dimension to energy distribution by sequentially activating different light emitting elements and fluorescent regions in different output periods. This time-based energy concentration allows full energy resources to be dedicated to each wavelength band during its active period, achieving high luminance in specific color periods without requiring physically larger or more complex simultaneous multi-color light sources
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 significantly improves luminance and color reproducibility by synthesizing light from red, green, blue, and yellow wavelength bands, enabling the projection of bright and vibrant images.
Implementation Method 1
a first light emitting element configured to emit a first wavelength band light
Implementation Method 2
a second light emitting element configured to emit a second wavelength band light
Implementation Method 3
a first fluorescent light emitting region irradiated with the second wavelength band light to emit a third wavelength band light
Data Source
AI summary
A light source unit includes: a first light emitting element configured to emit a first wavelength band light; a second light emitting element configured to emit a second wavelength band light; a luminescent wheel configured to have a first fluorescent light emitting region irradiated with the second wavelength band light to emit a third wavelength band light, and a second fluorescent light emitting region that emits a fourth wavelength band light including a wavelength band of the first wavelength band light and the third wavelength band light having a wavelength band adjacent to the first wavelength band light being provided in parallel in a circumferential direction; a color wheel configured to have a second transmissive region that transmits the first wavelength band light to the fourth wavelength band light, and a third transmissive region that transmits only the first wavelength band light or transmits only the first wavelength band light and the second wavelength band light being installed in parallel in the circumferential direction, and synchronously rotate with the luminescent wheel; and a controller configured to cause the second wavelength band light to be emitted in each output period and the first wavelength band light to be emitted in the output period in which the fourth wavelength band light is emitted, in a plurality of output periods in a frame.