Aspect Ratio Conversion in Optical Projection Systems
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Solution Overview
Problem
Existing optical projection systems face challenges in maintaining balanced light usage efficiency and telecentricity when converting aspect ratios, as external converters increase projector size and complexity, and rear arrangement-type relay systems restrict telecentricity and are not suitable for optical projection systems.
Innovation Solution
An optical projection system with a diaphragm and adjustable lens groups, including an adjustment optical device group and a rotationally symmetric lens group, which can be interchanged on the optical path to control aspect ratios and maintain telecentricity, allowing for balanced light usage and precise image projection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a front arrangement-type converter is used for aspect ratio conversion, then aspect ratio conversion is achieved, but the projector size increases and the optical system becomes more complex
Solution Approach 1:
The patent integrates the aspect ratio conversion function directly into the projector's internal optical system by combining the conversion lens group with the projection lens group. This merging eliminates the need for separate external converters, thereby reducing device complexity while maintaining aspect ratio conversion capability.
Solution Approach 2:
The projection lens group is designed to perform multiple functions: both standard image projection and aspect ratio conversion. By making the projection lens group universal, the system can handle different aspect ratios without requiring additional dedicated components, thus reducing overall system complexity.
2Adaptability or versatility
If a rear arrangement-type relay system is used for aspect ratio conversion, then aspect ratio conversion is achieved, but telecentricity is degraded and light usage efficiency becomes unbalanced
Solution Approach 1:
The patent applies different optical properties to different parts of the lens system. The conversion lens group has specific focal lengths in the vertical and horizontal directions to achieve aspect ratio conversion, while the projection lens group is designed to maintain telecentricity. This local differentiation of optical properties allows both functions to coexist without compromising telecentricity.
Solution Approach 2:
The patent employs movable lens groups that can be positioned at different locations along the optical path. By dynamically adjusting the position of the conversion lens group relative to the projection lens group, the system can maintain optimal telecentricity while performing aspect ratio conversion, avoiding the fixed limitations of rear arrangement-type systems.
3Adaptability or versatility
If an external converter is used for aspect ratio conversion, then aspect ratio conversion is achieved, but the adjustment of the optical system becomes more complex
Solution Approach 1:
By merging the aspect ratio conversion function into the internal optical system, the patent eliminates the need for separate external converters that would require independent adjustment. The unified optical system can be adjusted as a single integrated unit, significantly simplifying the adjustment process.
4Stability of the object's composition
If lenses are not replaced in the optical projection system, then system stability is maintained, but a general-purpose relay system with interchangeable lenses is not necessary
Solution Approach 1:
The patent designs the projection lens group to be universal, capable of performing both standard projection and aspect ratio conversion functions. This universality provides the necessary adaptability without requiring lens replacement, thereby maintaining system stability while achieving versatility through a fixed optical configuration.
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 system achieves balanced light usage and high telecentricity in both longitudinal and lateral directions, enabling efficient aspect ratio conversion and maintaining image quality without increasing projector size or complexity.
Implementation Method 1
an adjustment optical device group having different powers in a longitudinal direction and a lateral direction of the optical modulation device
Implementation Method 2
a rotationally symmetric lens group including one or more rotationally symmetrical lenses having the same power in a longitudinal direction and a lateral direction
Implementation Method 3
a diaphragm which restricts a passage of light flux
Data Source
AI summary
An optical modulation device side lens group has different powers in the longitudinal direction and the lateral direction of a liquid crystal panel. Therefore, as the entire system of the optical projection system, the optical modulation device side lens group has different magnification in the longitudinal and lateral directions. Therefore, it is possible to make the aspect ratio of an image of the liquid crystal panel different from the aspect ratio of an image projected on a screen. That is, conversion can be performed on an aspect ratio. At this time, a distance p between each focus or a diaphragm and the screen SC side end surface of the optical modulation device side lens group satisfies the conditional expressions, so it is possible to achieve a predetermined or higher telecentricity in both states, that is, a first operating state and a second operating state.