Projector Lighting Device Color Balance Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing projector systems using phosphor-based lighting devices face challenges in maintaining accurate color balance due to temperature-related deterioration of semiconductor lasers and phosphor degradation, leading to shifts in color balance and inefficiencies in light emission, particularly exacerbated by blue crosstalk from yellow fluorescent light.
Innovation Solution
A lighting device and projector system that includes a first light source for yellow fluorescent light, a second light source for blue light, a light sensor to detect the blue component and a distinct color component within the yellow fluorescent light, and a control unit to adjust the luminance of both light sources based on measured light quantities to achieve a predetermined ratio, thereby correcting color balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the first blue semiconductor laser and second blue semiconductor laser are used to generate yellow fluorescent light and blue light respectively, then the projector can achieve high brightness and color gamut, but temperature-related deterioration of the semiconductor lasers and phosphor degradation cause shifts in color balance over time
Solution Approach 1:
The system performs preliminary measurement of the blue component in yellow fluorescent light and stores this information for later compensation. By measuring the blue crosstalk characteristic in advance and using it to calculate correction values, the system proactively addresses color balance deterioration before it affects image quality, thereby maintaining reliable color reproduction over time despite phosphor degradation and laser aging
Solution Approach 2:
The system implements a feedback mechanism where the measured blue component quantity from yellow fluorescent light is used to calculate and apply correction values to the blue light output. This closed-loop control continuously compensates for color balance shifts caused by temperature changes and component degradation, ensuring stable color reproduction while maintaining high brightness output
2Loss of energy
If the yellow fluorescent light from the phosphor is transmitted through the dichroic mirror together with the blue light, then the light emission efficiency is improved, but blue crosstalk from the yellow fluorescent light interferes with the blue light component and complicates color balance adjustment
Solution Approach 1:
The system segments the detection process by separately measuring the blue component within yellow fluorescent light using a dedicated blue detection channel. By isolating the blue wavelength measurement from the overall yellow light measurement, the system can precisely quantify blue crosstalk without interference from other wavelengths, enabling accurate compensation while maintaining efficient light transmission through the dichroic mirror
Solution Approach 2:
The system introduces an intermediary measurement step that detects the blue component quantity in yellow fluorescent light before applying correction. This intermediary detection acts as a mediator between the mixed light transmission and final color balance adjustment, allowing the system to maintain high light emission efficiency through the dichroic mirror while accurately compensating for blue crosstalk effects
3Manufacturing precision
If the luminance of the first blue semiconductor laser is adjusted to correct color balance, then the color accuracy is improved, but the adjustment time increases and productivity decreases
Solution Approach 1:
The system performs preliminary measurement and calculation of correction values during the manufacturing process. By measuring the blue component in yellow fluorescent light in advance and pre-calculating the necessary luminance adjustment values, the system enables rapid color balance correction during assembly without requiring time-consuming iterative adjustments, thereby improving both color accuracy and production efficiency
Solution Approach 2:
The system replaces manual or iterative mechanical adjustment methods with an automated calculation and control system. By using measured blue component data to automatically calculate correction values and control laser luminance, the system eliminates time-consuming trial-and-error adjustment processes, achieving high color balance accuracy rapidly during manufacturing
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 solution enables precise adjustment of red, green, and blue light ratios, effectively mitigating the effects of temperature-related deterioration and phosphor degradation, ensuring accurate color balance and improved light emission efficiency.
Implementation Method 1
The phosphor wheel has a phosphor region that contains a phosphor that emits yellow fluorescent light in response to excitation by the first blue light
Implementation Method 2
The dichroic mirror is a color combination element in which the cutoff wavelength is set to approximately 90 nm and has characteristics of high reflectivity for a wavelength component which is shorter than the cutoff wavelength and high transmission for a wavelength component which is longer than the cutoff wavelength
Implementation Method 3
The yellow fluorescent light that is transmitted through the dichroic mirror and the second blue light that is reflected by the other surface of the dichroic mirror are incident to one end surface of the rod integrator along the same light path
Data Source
AI summary
A lighting device includes: a first light source that supplies yellow fluorescent light; a second light source that supplies blue light; a light sensor that detects the light quantity of a blue component of combined light, in which the yellow fluorescent light and blue light have been combined, and the light quantity of a first color component that is contained in the yellow fluorescent light and that differs from the blue component; and a control unit that adjusts the luminance of the first and second light sources. The control unit acquires each of a first light quantity that is the light quantity of the first color component and a second light quantity that is the light quantity of the blue component in a first state in which the first light source is ON and the second light source is OFF, and acquires a third light quantity.