Luminescent Wheel Synchronization for Projector Light Source Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light source units for projectors face issues with low light utilization efficiency, temperature-related deterioration of luminescent materials, and flickering due to uneven excitation light distribution, particularly when using high-intensity discharge lamps or luminescent wheels with fixed excitation light sources.
Innovation Solution
A light source unit with a luminescent wheel and an excitation light shining device, where the light source control device synchronizes the rotation speed of the luminescent wheel with the excitation light emission periods, and includes red and blue semiconductor light sources to enhance luminescence without a green light emitting diode, ensuring even excitation and prolonged performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If excitation light is shone continuously on luminescent material layers to maintain high luminance, then light output is improved, but temperature increases causing deterioration of luminescent materials
Solution Approach 1:
The patent applies periodic action by controlling the excitation light source to emit light in alternating periods with the luminescent wheel rotation, rather than continuous emission. The excitation light is turned on during specific time periods when corresponding luminescent light emitting areas pass through the light emission position, and turned off during other periods, creating a periodic excitation pattern that reduces cumulative heat buildup while maintaining required luminance output.
Solution Approach 2:
The patent implements dynamics by synchronizing the excitation light emission timing with the rotational position of the luminescent wheel. The control device dynamically adjusts the excitation light emission periods based on the rotation speed and position of the luminescent wheel, ensuring excitation light is applied only when needed for each luminescent light emitting area, thereby optimizing light output while minimizing thermal stress on the luminescent materials.
2Speed
If the luminescent wheel rotates at high speed to increase frame rate, then image quality is improved, but synchronization with excitation light emission becomes difficult causing flickering
Solution Approach 1:
The patent employs feedback by using a sensor to detect the rotational position of the luminescent wheel and feeding this information back to the control device. The control device uses this feedback signal to precisely time the excitation light emission, ensuring that excitation light is applied at the correct moment when each luminescent light emitting area passes through the light emission position, maintaining synchronization even at varying rotation speeds and preventing flickering.
3Productivity
If excitation light is applied to all luminescent light emitting areas simultaneously, then all colors are emitted at once, but light utilization efficiency decreases due to sequential emission requirements
Solution Approach 1:
The patent applies segmentation by dividing the luminescent wheel into distinct luminescent light emitting areas corresponding to different colors (red, green, blue), and controlling excitation light emission separately for each area in sequence. Rather than attempting to excite all areas simultaneously, the system segments the excitation process to match the sequential passage of each luminescent area through the light emission position, thereby improving light utilization efficiency.
Solution Approach 2:
The patent implements continuity of useful action by ensuring that excitation light is continuously applied to the luminescent wheel in a sequential manner as different luminescent light emitting areas pass through the light emission position. This continuous sequential excitation maintains uninterrupted color emission throughout each rotation cycle, optimizing the utilization of excitation light energy across all luminescent materials.
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 maintains long-term performance of luminescent material layers, prevents flickering, and achieves enhanced luminance and color balance by dynamically controlling the excitation light distribution and rotation speed, optimizing light emission efficiency.
Implementation Method 1
a luminescent wheel on which a luminescent material layer or layers which convert ultraviolet light emitted from the excitation light source into visible light are formed
Implementation Method 2
a luminescent wheel on which a luminescent material layer or layers which convert ultraviolet light emitted from the excitation light source into visible light are formed
Data Source
AI summary
To provide a light source unit which prevents a reduction of light emitting efficiency in a luminescent material layer and a projector, a projector includes a light source unit, a display device and a projector control device, the light source unit includes an excitation light shining device, a luminescent wheel on which a luminescent material layer is laid circumferentially which receives the excitation light to emit luminescent light of a predetermined wavelength band, two types of light source devices for emitting light rays of wavelength bands which are different from the predetermined wavelength band, and a light source control device for controlling individually the emission of light by the excitation light shining device and the two types of light source devices and for controlling the rotating speed of the luminescent wheel in accordance with a period of time when the excitation light shining device is turned on.