Shading Element for Stray Light Reduction in Miniaturized DLP Projectors
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Solution Overview
Problem
Miniaturized DLP projectors face significant challenges in reducing stray light, which affects image quality due to the close proximity of components, leading to increased complexity and cost in existing solutions such as surface roughening and baffles.
Innovation Solution
Incorporating a single or multiple shading elements formed in one-piece with the condensing element to block off-state and flat-state light, strategically positioned between the camera module and the image beam providing device, or between the condensing element and the image beam providing device, to effectively reduce stray light without additional assembly complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If surface roughening is applied to decrease stray light, then stray light is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts the light-blocking function from the condensing element surface treatment and implements it through a separate shading element. This shading element is positioned between the light source and the condensing element to block stray light before it reaches the condensing element, thereby reducing stray light without requiring complex surface roughening treatments on the condensing element.
Solution Approach 2:
The patent introduces a shading element as an intermediary component between the light source and the condensing element. This shading element acts as a mediator that blocks stray light (off-state light and flat-state light) from reaching the condensing element, thereby reducing stray light projection without modifying the condensing element's surface properties.
2Object-affected harmful factors
If baffles are added to block stray light, then stray light is reduced, but device complexity increases
Solution Approach 1:
The patent merges the shading element with the light source assembly or housing structure, integrating the light-blocking function into an existing component rather than adding a separate baffle. This integration reduces the number of discrete parts and simplifies assembly while maintaining effective stray light blocking.
Solution Approach 2:
The shading element is designed to perform multiple functions: it blocks off-state light, blocks flat-state light, and can be integrated with the light source housing or mounting structure. This multi-functionality reduces the need for separate components and simplifies the overall device architecture.
3Volume of moving object
If component spacing is reduced for miniaturization, then projector size is reduced, but stray light increases
Solution Approach 1:
The patent applies preliminary action by blocking stray light at the earliest possible point in the optical path - immediately after the light source and before the light reaches the condensing element. The shading element is positioned to intercept off-state light and flat-state light before they can cause stray light problems, enabling miniaturization without compromising stray light control.
Solution Approach 2:
The shading element serves as an intermediary that enables closer component spacing by handling the stray light problem at the source rather than requiring larger spacing to allow stray light to diverge before reaching sensitive components.
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 significantly decreases stray light efficiency from 0.1609% to 0.0028% for off-state light and from 1.6783% to 0.0008% for flat-state light, maintaining projection efficiency and uniformity while simplifying assembly and reducing costs.
Implementation Method 1
a first shading element being not located in a path of the image beam to enter the camera module and configured at one of a first position between the camera module and the condensing element, and a second position between the image beam providing device and the condensing element to block the off-state light
Implementation Method 2
a condensing element configured to condense the light beam after the light beam is unified by the integrator
Implementation Method 3
By deflecting of the micromirrors on the DMD, the incident light may be reflected at different angles and the bright and dark effects of the light spots are achieved
Data Source
AI summary
A projection device having an image beam and an off-state light is provided, which includes a camera module, a condensing element, a digital micromirror device (DMD) and a shading element, wherein the DMD allows the image beam to enter the camera module, and the shading element is configured between the DMD and the condensing element to block the off-state light.