Light Source Device Optical Path Correction for Projection Systems
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Solution Overview
Problem
The existing light source devices in projection technology suffer from low light utilization rates and poor color uniformity due to the loss of exciting light and uneven color distribution in the projected image, primarily caused by the central portion lacking blue light, resulting in a yellowish center and uneven color uniformity.
Innovation Solution
A light source device with a light guiding system and a wavelength conversion device that guides the exciting light to a wavelength conversion section and a reflective section, ensuring no light returns along the original path, and uses an optical path correcting assembly to coincide the imaging positions of the excited and reflected light, achieving uniform spatial distribution and improved light utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a region light splitter with blue-transmitting and yellow-reflective region is used to separate blue light and yellow light, then the light can be separated into different regions, but the blue light transmitted through the central region is lost and does not reach the square bar, resulting in color unevenness
Solution Approach 1:
Instead of transmitting blue light through the central region (which causes loss), the patent inverts the approach by making the central region reflective for blue light and the peripheral region transmissive for blue light. This ensures blue light is reflected to the square bar while avoiding the transmission loss problem.
Solution Approach 2:
The patent applies different optical properties to different regions: the central region has blue light reflective property while the peripheral region has blue light transmissive property. This local differentiation ensures optimal light distribution - blue light is reflected centrally while yellow light passes through peripherally, achieving uniform color distribution.
2Productivity
If the blue light is transmitted through the blue-transmitting and yellow-reflective region to reach the phosphor color wheel, then the light utilization rate increases, but the transmitted blue light is lost after passing through the region light splitter
Solution Approach 1:
The patent inverts the optical properties: the central region reflects blue light instead of transmitting it, while the peripheral region transmits blue light. This inversion ensures blue light is directed to the square bar through reflection rather than transmission, preventing loss and improving light utilization.
Solution Approach 2:
The patent extracts the blue light path from the central region and redirects it through reflection to the square bar, separating it from the yellow light path that passes through the peripheral region. This extraction ensures blue light is efficiently utilized without being lost in transmission.
3Loss of energy
If the blue light is reflected by the blue-reflective and yellow-reflective region, then the blue light can reach the square bar, but the central portion of the beam lacks blue light resulting in yellowish center
Solution Approach 1:
The patent applies different optical properties to different regions: the central region reflects blue light to ensure it reaches the square bar, while the peripheral region transmits blue light. This local differentiation ensures uniform blue light distribution across the beam, preventing the yellowish center problem.
Solution Approach 2:
Instead of making the central region transmissive (which causes blue light loss), the patent makes it reflective to redirect blue light to the square bar. This inversion, combined with peripheral transmission, achieves both blue light delivery and uniform color distribution.
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 enhances light utilization and ensures spatial distribution uniformity of the emitted light, addressing the issues of low brightness and color unevenness, resulting in improved color uniformity and increased light efficiency.
Implementation Method 1
the wavelength conversion section absorbs the first exciting light and emits excited light
Implementation Method 2
the first exciting light is obliquely incident to a surface of the reflective section and is reflected to form second exciting light
Implementation Method 3
the optical path correcting assembly is located on an optical path of the second exciting light and is configured to reflect the second exciting light in such a manner that a main optical axis of the reflected second exciting light coincides with a main optical axis of the excited light and further to change a beam angular distribution of the second exciting light
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~4A
AI summary
Provided is a light source device and a projection system. The light source device includes a first light source (201), a light guiding system and a wavelength conversion device (206). The first light source (201) emits first exciting light which is incident to the light guiding system along an incidence light channel. The light guiding system guides the first exciting light to the wavelength conversion device (206). The wavelength conversion device (206) includes a wavelength conversion section and a reflective section. The wavelength conversion section absorbs the first exciting light and emits excited light. The first exciting light is obliquely incident to a surface of the reflective section and reflected to form second exciting light. The light guiding system collects the excited light and the second exciting light and guides them to be emitted along an emission light channel. The light guiding system includes an optical path correcting assembly (209), and the optical path correcting assembly (209) is located on an optical path of the second exciting light, and reflects the second exciting light in such a manner that main optical axes of the reflected second exciting light and the excited light coincide, and changes a beam angular distribution of the second exciting light.