Light Source Unit for Compact Projectors
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Solution Overview
Problem
Conventional projectors face challenges in miniaturization due to the need for light tunnels to control laser diode emissions, which result in a Gaussian intensity distribution that is not suitable for optical modulators and limits the projector's size reduction.
Innovation Solution
A light source unit incorporating a light emitting device with high intensity uniformity in a predetermined direction and a superposition transforming optical device to control intensity distribution in the unstable direction, using cylindrical lens arrays and intensity transforming lenses to convert Gaussian distributions into top-hat distributions, allowing for compact projector design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light tunnel is used to control laser diode emissions, then the intensity distribution can be transformed, but the projector size increases
Solution Approach 1:
The invention divides the intensity transformation function into two separate optical components: an intensity transforming lens that handles the major axis direction, and a superposition transforming optical device that handles the minor axis direction. This segmentation allows each component to be optimized independently, reducing the overall optical path length and projector size while achieving uniform intensity distribution in both directions.
Solution Approach 2:
The invention addresses the two-dimensional intensity distribution problem by applying different optical transformation methods along each axis dimension. The intensity transforming lens operates primarily in one dimension (major axis), while the superposition transforming optical device operates in the perpendicular dimension (minor axis), enabling compact design without compromising uniformity in either direction.
2Volume of moving object
If conventional laser diodes with Gaussian distribution are used, then the light source is compact, but the intensity distribution is not suitable for optical modulators
Solution Approach 1:
The invention introduces two intermediary optical components between the laser diode and the optical modulator: the intensity transforming lens and the superposition transforming optical device. These intermediaries transform the Gaussian intensity distribution of the compact laser diode into a uniform top-hat distribution suitable for optical modulators, maintaining both compactness and uniformity.
Solution Approach 2:
The invention changes the intensity distribution parameter of the laser beam from Gaussian to top-hat distribution through optical transformation. The intensity transforming lens modifies the beam profile in the major axis direction, while the superposition transforming optical device modifies it in the minor axis direction, achieving uniform intensity distribution while preserving the compact laser diode source.
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 production of rectangular illumination with uniform intensity, enhancing optical efficiency and allowing for a smaller projector size without the need for large optical components like light tunnels or microlens arrays.
Implementation Method 1
an intensity transforming lens formed to control the intensity distribution in the predetermined direction and on which the light emitted from the light emitting device is incident
Implementation Method 2
a superposition transforming optical device formed to control the intensity distribution in the unstable direction by dividing the intensity distribution into a plurality of directions and superposing divided intensity distributions one on the other
Data Source
AI summary
A light source unit of the present invention includes a light emitting device emitting light having a characteristic in which emitted light travels in a predetermined direction in which a uniformity in intensity distribution relative to an axis of the emitted light is high and an unstable direction in which a uniformity in intensity distribution relative to the axis of the emitted light is lower than that in the predetermined direction, the unstable direction being at right angles to the predetermined direction, an intensity transforming lens formed to control the intensity distribution in the predetermined direction and on which the light emitted from the light emitting device is incident, and a superposition transforming optical device formed to control the intensity distribution in the unstable direction by dividing the intensity distribution into a plurality of directions and superposing divided intensity distributions one on the other.