Lighting Device Optical Coupling Cutout Vignetting
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Solution Overview
Problem
Conventional lighting devices for projectors experience vignetting when guiding coupled light beams from pair of light source lamps, leading to reduced light intensity and difficulty in forming high-brightness projections.
Innovation Solution
A lighting device with an optical coupling device featuring reflection members, such as triangular prisms with cutout portions, that reflect and couple light beams from multiple light sources without blocking, and a homogenization device to ensure efficient light transmission and high-brightness output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a reflector plate with V-shape in section is used to couple light beams from a pair of light source lamps, then the light beams can be reflected and coupled in one direction, but vignetting occurs in the coupled light beam by the rod integrator which decreases the quantity of light beam incident on the rod integrator
Solution Approach 1:
The reflector plate is divided into multiple reflection members (first reflection member and second reflection member) arranged in parallel. Each reflection member has a reflection surface that reflects light from one light source. This segmentation allows independent optimization of each reflection member to prevent vignetting while maintaining coupling efficiency.
Solution Approach 2:
A light guide plate is introduced as an intermediary component between the reflection members and the rod integrator. The light guide plate includes a light incident surface that receives light from the reflection members and a light extraction surface that extracts light uniformly. This intermediary structure prevents vignetting by redistributing light before it enters the rod integrator.
2Stability of the object's composition
If the coupled light beam is formed with optical axes of the pair of light source lamps horizontally separated from each other with a predetermined gap, then the light beams can be coupled, but the quantity of light beam incident on the rod integrator is decreased
Solution Approach 1:
The invention transitions from horizontal separation of optical axes to vertical arrangement of reflection members. The first and second reflection members are arranged in the vertical direction with their reflection surfaces facing each other. This dimensional change allows light from both sources to be coupled without horizontal gap while preventing vignetting through the light guide plate's light extraction function.
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 effectively couples and homogenizes light beams, preventing vignetting and enabling high-brightness light output for projection applications.
Implementation Method 1
an optical coupling device including a plurality of reflection members each having a reflection surface, the optical coupling device reflecting a plurality of light beams emitted in a plurality of directions from the plurality of light sources at the reflection surfaces of the plurality of reflection members and coupling the plurality of light beams to generate a coupled light beam in an identical direction
Data Source
AI summary
A lighting device includes plural light sources, an optical coupling device including plural reflection members each having a reflection surface, the optical coupling device reflecting plural light beams emitted in plural directions from the plural light sources at the reflection surfaces of plural reflection members and coupling the plural light beams to generate a coupled light beam in an identical direction, and a homogenization device that homogenizes the coupled light beam from the optical coupling device. In at least one of the plural reflection members, a cutout portion is formed to transmit an incident light beam on the reflection surface of the other reflection member such that the incident light beam is not blocked by a part of a region of the at least one reflection member on the way to the reflection surface of the other reflection member.