Light Source Device Optical Path Redirection for Compact Projectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to reduce the size of a projector's light source device while maintaining brightness, as increasing the number of light emitting elements tends to increase the device's size due to the larger condensing lens required for excitation light condensation.
Innovation Solution
The light source device includes a light source unit with two mounting substrates and a base member, a wavelength conversion unit, and an optical unit with a condensing optical system and a pickup optical system. The optical-path changing member reflects light from one light emitting element to align closer to the other, allowing for a smaller lens diameter and reduced device size, and the wavelength conversion unit is housed in a diameter-reduced section of the optical housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the number of light emitting elements is increased to generate bright illumination light, then the brightness is improved, but the outer diameter of the condensing lens increases and the device size increases
Solution Approach 1:
The patent introduces an optical-path changing member (prism) that redirects light from the second light emitting element along a different spatial path. This allows multiple light sources to contribute to the same condensing lens without requiring the lens diameter to scale proportionally with the number of light emitting elements, thus breaking the direct dimensional relationship between light source count and lens size.
Solution Approach 2:
The patent divides the light emitting elements into multiple groups (first light emitting element, second light emitting element, etc.) with different optical paths. The optical-path changing member segments the light paths so that light from different elements can be combined efficiently, allowing brightness enhancement without proportional increase in lens diameter.
2Illumination intensity
If the outer diameter of the condensing lens is increased to condense excitation light from multiple light emitting elements, then the brightness is improved, but the device size increases
Solution Approach 1:
The optical-path changing member acts as an intermediary that redirects and combines light paths before they reach the condensing lens. This intermediary component allows multiple light sources to be effectively combined without requiring a proportionally larger lens diameter, as the optical path modification enables more efficient use of the existing lens aperture.
3Volume of moving object
If the device size is reduced, then the portability is improved, but the heat dissipation becomes more difficult
Solution Approach 1:
By introducing the optical-path changing member that modifies light propagation paths, the patent enables more compact arrangement of optical components. This dimensional reorganization allows reduced device size while maintaining adequate spacing for heat dissipation, as the redirected light paths create more flexible spatial configuration options.
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 enables the generation of bright illumination light while minimizing the device's size, preventing an increase in the light source device's dimensions and improving heat dissipation and assemblability.
Implementation Method 1
an optical-path changing member including a first reflection surface and a second reflection surface and configured to reflect, with the first reflection surface, the light emitted from the second light emitting element in a direction in which the light is brought closer to the light emitted from the first light emitting element
Implementation Method 2
a wavelength conversion unit including: a wavelength conversion wheel configured to emit, from a second surface opposite to a first surface, wavelength-converted light obtained by wavelength-converting light emitted from the first light emitting element and the second light emitting element
Implementation Method 3
a condensing optical system configured to condense the light emitted from the first light emitting element and the second light emitting element on the wavelength conversion wheel
Data Source
AI summary
A light source device according to an aspect of the present disclosure includes a light source unit including a base member on which mounting substrates on which first and second light emitting elements are mounted are placed, a wavelength conversion unit including a wavelength conversion wheel configured to emit wavelength-converted light and a wheel housing configured to house the wavelength conversion wheel, and an optical unit including a condensing optical system configured to condense light emitted from the first and second light emitting elements on the wavelength conversion wheel, a pickup optical system configured to pick up the wavelength-converted light, and an optical housing. The condensing optical system includes a first lens on which the light emitted from the first light emitting element is directly made incident and an optical-path changing member configured to make the light emitted from the second light emitting element incident on the first lens.