Magnification Conversion Optical Unit for Focal Length Adjustment
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Solution Overview
Problem
Existing optical systems face challenges in easily changing focal length while maintaining appropriate optical performance, particularly when using magnification conversion optical units, due to inappropriate lens configurations and difficulty in rapid insertion and removal.
Innovation Solution
An optical system design that includes a magnification conversion optical unit insertable and removable between specific lens units, maintaining a constant total lens length, with a configuration that allows for easy size reduction and enhanced optical performance by optimizing the refractive powers and positions of the magnification conversion optical unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a magnification conversion optical unit is inserted into the optical path to change the focal length, then the focal length range is extended, but the optical performance is significantly reduced due to inappropriate lens configuration
Solution Approach 1:
The patent applies parameter changes by precisely controlling the focal length of the magnification conversion optical unit and its insertion position relative to the aperture stop. By satisfying specific conditional expressions for these parameters, the system maintains appropriate optical performance while achieving focal length conversion. This resolves the contradiction by showing that with proper parameter selection, both extended focal length range and maintained optical performance are achievable.
2Reliability
If the magnification conversion optical unit is made larger to improve optical performance, then the optical performance is maintained, but rapid insertion and removal becomes difficult
Solution Approach 1:
The patent resolves this contradiction by changing the parameter of the magnification conversion optical unit's focal length to satisfy specific conditional expressions. This allows the unit to be compact in size while maintaining appropriate optical performance, thereby enabling rapid insertion and removal without sacrificing optical quality.
3Ease of operation
If the magnification conversion optical unit is inserted at a position with wide air gap to facilitate insertion, then insertion is easier, but the optical performance is significantly reduced
Solution Approach 1:
The patent applies preliminary action by pre-determining the optimal insertion position of the magnification conversion optical unit relative to the aperture stop before actual insertion. By satisfying the conditional expression for the distance relationship between the optical unit and aperture stop, the system ensures both ease of insertion and maintenance of appropriate optical performance, resolving the contradiction between these two requirements.
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 easy change in focal length with maintained optical performance, reducing the size of the magnification conversion unit and improving image stabilization without increasing sensitivity.
Implementation Method 1
a magnification conversion optical unit EXT... configured by a front lens unit EXTa having a positive refractive power and a rear lens unit EXTb having a negative refractive power
Data Source
Figure 1
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AI summary
An optical system (OL) includes a magnification conversion optical unit (EXT) configured to be insertable and removable at a position between an aperture stop (SP) and an image plane (IP) of the optical system in order to change a focal length of the optical system, a total lens length of the optical system is constant before and after insertion of the magnification conversion optical unit, and a length Lp on an optical axis from the aperture stop to the image plane of the optical system, and a length Le on the optical axis from a lens surface closest to an object side of the magnification conversion optical unit to the image plane when the magnification conversion optical unit is inserted are appropriately set.