Anamorphic Projection Optical System Aspect Ratio Shift Compensation
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Solution Overview
Problem
Projection optical systems face issues with positional deviation of the projection image due to aspect ratio conversion, particularly when the center of the image element is not aligned with the optical axis, leading to incorrect positioning on the screen.
Innovation Solution
A projection optical system with a first group and a second anamorphic optical system that can advance and retract, combined with a driving section featuring shift and zoom mechanisms, allows for adjustment of the image position to maintain alignment and correct deviation caused by aspect ratio changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the second group (anamorphic optical system) advances and retracts to convert aspect ratio, then the aspect ratio conversion is achieved, but the projection position deviates from the center of the screen
Solution Approach 1:
The patent introduces a driving section as an intermediary mechanism that includes both shift driving and zoom driving. The shift driving mechanism acts as a mediator to correct the positional deviation caused by the anamorphic optical system's advancement and retraction, while the zoom driving mechanism mediates to maintain proper projection magnification. This intermediary driving section resolves the contradiction by actively compensating for the position deviation while preserving the aspect ratio conversion capability.
Solution Approach 2:
The patent employs parameter changes by dynamically adjusting the position of the first group and the magnification of the projection optical system through the driving section. When the second group advances or retracts for aspect ratio conversion, the driving section changes the positional parameters (through shift driving) and magnification parameters (through zoom driving) to compensate for the resulting projection position deviation, thereby maintaining accurate screen positioning despite the parameter changes in the anamorphic system.
2Adaptability or versatility
If tilt projection is used to project image with center out of optical axis, then projection flexibility is improved, but positional deviation upon aspect ratio conversion increases
Solution Approach 1:
The patent implements a feedback mechanism through the driving section that continuously monitors and corrects the projection position. When tilt projection is used and the center of the image element is out of the optical axis, the driving section detects the resulting positional deviation upon aspect ratio conversion and provides corrective feedback by adjusting the first group's position and magnification, thereby maintaining proper screen alignment despite the initial misalignment.
Solution Approach 2:
The patent applies dynamics by making the first group and the projection magnification dynamically adjustable through the driving section. This dynamic adjustment capability allows the system to adapt to the conditions created by tilt projection, where the image center is out of the optical axis, and automatically corrects the projection position during aspect ratio conversion, thus resolving the conflict between projection flexibility and position alignment precision.
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
Enables precise control over the aspect ratio conversion and positional adjustment, ensuring the projection image remains centered and correctly positioned on the screen, even when the aspect ratio is altered.
Implementation Method 1
a second group including an anamorphic optical system which has different power in a vertical direction and a horizontal direction of the light modulation element
Data Source
AI summary
A second group has different power in the vertical direction and the horizontal direction of the liquid crystal panel. Therefore, the horizontal-to-vertical ratio of the image of the liquid crystal panel and the horizontal-to-vertical ratio of the image projected on the screen can be set to be different. That is, the projection optical system is able to convert the aspect ratio which is a ratio of width and height. At this time, at the time of converting the aspect ratio, that is, at the time of switching the projection state, it is possible to adjust the position of the image on the screen through a zoom operation or a shift operation of the first driving mechanism or the fourth driving mechanism.