Retrofocus Zoom Lens Layout for Wide-Angle Ghost Suppression
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Solution Overview
Problem
Wide angle lenses suffer from ghost effects due to unnecessary light reflections, which degrade optical performance and image quality.
Innovation Solution
A zoom lens design with a first lens unit having negative refractive power and subsequent lens units arranged to control light reflections, using specific curvature and refractive index ratios to minimize ghosting while maintaining high optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a wide angle lens is designed with a large lens open angle to achieve a wide view angle, then the view angle is improved, but ghost effects occur due to unnecessary light reflections
Solution Approach 1:
The invention converts the harmful reflected light into a beneficial effect by designing the second lens surface with a specific radius of curvature (24.17403 mm) and the third lens surface with a radius of curvature (186.38308 mm) such that obliquely reflected light from the object-side lens surface of the second lens is redirected away from the image plane, thereby eliminating ghost effects while maintaining the wide view angle
Solution Approach 2:
The invention changes the optical parameters by specifying precise radius of curvature values for the second and third lens surfaces and controlling the air gaps between lens surfaces (7.218 mm between second and third surfaces, 6.342 mm between fourth and fifth surfaces) to control the path of reflected light and prevent it from reaching the image plane
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 design effectively reduces ghost images and enhances optical performance by controlling light reflections, ensuring high-quality imaging across a wide zoom range.
Implementation Method 1
a second lens surface having a radius of curvature of 24.17403 mm, with an air gap between the second and third lens surfaces being 7.218 mm, and of which the third lens surface has a radius of curvature of 186.38308 mm
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A zoom lens (L0) includes a first lens unit (L1) having a negative refractive power, a second lens unit (L2) having a positive refractive power, and two or more additional lens units. At zooming, the first lens unit (L1) moves, and an interval between adjacent lens units changes. The refractive index of a negative lens A disposed on a most object side of negative lenses included in the first lens unit (L1) is higher than or equal to 1.89, and the negative lens A and a lens B disposed adjacent to an image side of the negative lens A satisfy a predetermined relationship.