Laser Diode Projector Elliptical Light Alignment
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Solution Overview
Problem
In projectors using laser diodes as light sources, the elliptical shape of light emitted by laser diodes leads to inefficiencies in light distribution and alignment with the DMD's image forming surface, resulting in color irregularities and reduced brightness of projected images.
Innovation Solution
The projector is designed with laser diodes and a display device configuration where the major axis of the elliptical light section is oriented parallel to the longer sides of the display device, ensuring uniform light distribution and alignment, reducing light loss and enhancing brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If laser diodes are used as light sources, then high-intensity light is obtained, but the elliptical shape of emitted light causes uneven distribution and alignment issues with the DMD
Solution Approach 1:
The patent applies asymmetry by intentionally matching the asymmetric elliptical light profile from laser diodes with an asymmetric arrangement of optical components. The cylindrical lens and reflecting mirror are positioned and oriented to complement the elliptical shape, transforming the asymmetry from a problem into a design feature that enables precise alignment with the DMD's micromirror array.
2Productivity
If the elliptical light section is not aligned with the display device, then light distribution is inefficient, but realigning requires changing the optical path configuration
Solution Approach 1:
The patent introduces a cylindrical lens as an intermediary optical element between the laser diode and the reflecting mirror. This intermediary component transforms and redirects the elliptical light profile, enabling efficient alignment with the DMD without requiring complex reconfiguration of the entire optical path. The cylindrical lens acts as a mediator that adapts the light shape to match the display device geometry.
3Speed
If reflecting mirrors are used to redirect laser beams, then light direction is changed, but misalignment between the elliptical light shape and mirror orientation causes light loss
Solution Approach 1:
The patent applies parameter changes by carefully controlling the orientation angle and positional parameters of the reflecting mirror relative to the elliptical light profile. The mirror is positioned at a specific angle that matches the major axis of the ellipse, ensuring optimal reflection efficiency. By adjusting these geometric parameters, the system achieves effective light direction control while minimizing energy loss.
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 improves the intensity of reflected light per unit area on the DMD, reduces color irregularity, and achieves a brighter projected image with improved illuminance uniformity.
Implementation Method 1
a radiation angle relative to a junction surface of the diode differs between a vertical direction and a horizontal direction. It is known that because of this characteristic, a section of light emitted from the laser diode takes an elliptic shape
Implementation Method 2
the direction of the axis of the laser beam is changed by 90 degrees by a reflecting mirror
Data Source
AI summary
There is provided a projector including a plurality of laser diodes and a rectangular display device on to which light emitted from the plurality of laser diodes is shone, wherein the display device is disposed so that a direction of a major axis of an elliptic section of light emitted from each of the plurality of laser diodes becomes substantially parallel to a direction of longer sides of the display device.