Imaging Lens Assembly with Movable Diaphragm for Depth of Field
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Solution Overview
Problem
Users of portable electronic devices, such as smartphones, face challenges in achieving a large depth of field while maintaining a compact lens size and small size, which existing imaging lens assemblies struggle to address effectively.
Innovation Solution
An imaging lens assembly comprising a sequence of lenses with specific refractive powers and surface types, including a movable diaphragm, aspheric surfaces, and carefully configured distances and thicknesses, which allows for a variable aperture and high imaging quality, enabling a large depth of field and compact structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the lens assembly size is reduced for compact portable devices, then the device compactness is improved, but the depth of field becomes smaller
Solution Approach 1:
The lens assembly is divided into six distinct lens elements with alternating positive and negative refractive powers, allowing each element to contribute differently to the overall optical performance. This segmentation enables compact sizing while maintaining adequate depth of field through coordinated design of individual elements.
Solution Approach 2:
Different regions of the lens assembly are designed with specific properties: the first lens has positive refractive power for convergence, the second and sixth lenses have negative refractive power for divergence and field correction, and the fourth lens incorporates an aspheric surface for aberration correction. This local differentiation optimizes both compactness and depth of field.
2Measurement precision
If the focal length is increased for better imaging, then the imaging quality is improved, but the lens assembly size increases
Solution Approach 1:
The lens assembly incorporates a movable diaphragm that can adjust its position to change the effective aperture and focal characteristics dynamically. This allows the system to achieve variable focal lengths and imaging qualities without proportionally increasing the physical length of the lens assembly.
Solution Approach 2:
The six lens elements are arranged in a compact nested configuration where each subsequent element builds upon the optical function of the previous ones. This nested arrangement maximizes the imaging performance within a minimized overall length by ensuring each element contributes efficiently to the total focal length.
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 solution achieves a balance of small size, compact structure, and high imaging quality, meeting the requirements for portable electronic devices by optimizing the refractive powers, surface types, and configurations of the lenses, thereby providing a large depth of field and variable aperture.
Implementation Method 1
a first lens with a positive refractive power, a second lens with a negative refractive power, a third lens with a refractive power, a fourth lens with a refractive power, a fifth lens with a refractive power and a sixth lens with a negative refractive power
Implementation Method 2
the object-side surface of the first lens to an image-side surface of the sixth lens include at least one aspheric mirror surface
Data Source
AI summary
The disclosure provides an imaging lens assembly, which sequentially includes, from an object side to an image side along an optical axis, a movable diaphragm, a first lens with a positive refractive power, a second lens with a negative refractive power, a third lens with a refractive power, a fourth lens with a refractive power, a fifth lens with a refractive power and a sixth lens with a negative refractive power, wherein TSmin is a distance from the movable diaphragm at a minimum distance from an imaging surface of the imaging lens assembly to an object-side surface of the first lens on the optical axis, TSmax is a distance from the movable diaphragm at a maximum distance from the imaging surface of the imaging lens assembly to the object-side surface of the first lens on the optical axis and EPDmin is a minimum entrance pupil diameter of the imaging lens assembly.