Projector Optical Element Shift for Color Shift Correction
Solution Overview
Problem
Image projecting apparatuses face significant deterioration in image quality due to color shift caused by assembly errors during the assembly of lenses into a lens barrel, leading to decentering lateral chromatic aberration, which is exacerbated by increasing resolution of image display elements.
Innovation Solution
The apparatus incorporates an optical system with an optical element that shifts in a direction perpendicular to the optical axis, accompanied by an adjusting mechanism to correct color shift, ensuring the optical element's combined Abbe number, focal length, and pixel pitch satisfy specific conditions to minimize decentering coma and tilt, thereby reducing color shift effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If assembly errors occur during lens assembly, then manufacturing complexity increases, but color shift and decentering aberration worsen
Solution Approach 1:
The patent introduces an adjusting mechanism that allows changing the positional parameters of optical elements after assembly. By enabling adjustment of lens positions in directions perpendicular to the optical axis, the system can compensate for assembly errors and reduce decentering lateral chromatic aberration without requiring extremely precise manufacturing.
Solution Approach 2:
The patent transforms the static lens assembly into a dynamic system where lens positions can be adjusted. The adjusting mechanism enables the optical elements to be repositioned during or after assembly, allowing the system to adapt to assembly variations and maintain optimal optical performance.
2Device complexity
If simple decentration adjustment is applied, then device complexity is reduced, but color shift reduction is insufficient
Solution Approach 1:
The patent divides the lens system into multiple adjustable components, with each optical element capable of independent adjustment in specific directions. This segmentation allows targeted correction of decentering aberrations by adjusting individual lenses, providing effective color shift reduction without requiring a completely complex redesign of the entire optical system.
3Manufacturing precision
If optical elements are decentered to correct assembly errors, then manufacturing precision requirements are relaxed, but decentering coma and tilt increase
Solution Approach 1:
The patent incorporates an adjusting mechanism that enables feedback-based correction of optical aberrations. By allowing post-assembly adjustment of lens positions, the system can detect and compensate for decentering effects, reducing both assembly error impacts and the resulting coma and tilt aberrations through iterative optimization.
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 approach effectively corrects color shift and maintains high image resolution by adjusting the optical element's position, ensuring minimal decentering coma and tilt, even with high-resolution image display elements, resulting in improved image quality with reduced color shift.
Implementation Method 1
an optical element that shifts in a direction having a component in a direction perpendicular to the optical axis... effectively corrects color shift and maintains high image resolution by adjusting the optical element's position, ensuring minimal decentering coma and tilt
Data Source
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AI summary
An image projecting apparatus includes an image display element, an optical system that projects an image displayed on the image display element onto a screen, an optical element that shifts in a direction perpendicular to an optical axis of the optical system, an adjusting mechanism that can shift the optical element in the direction perpendicular to the optical axis, and a holding member that fixes the optical element to a lens barrel, wherein a combined Abbe number vdch of materials of the optical element with respect to a d-line, a combined focal length fdch of the optical element with respect to the d-line, and the pixel pitch P of the image display element satisfy an appropriate condition.