Multi-Block Image Pickup Lens Design for Compact Mobile Terminals
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Solution Overview
Problem
Existing image pickup lenses face challenges in achieving compactness, mass productivity, and heat resistance while maintaining optical quality, with issues such as diffractive surfaces causing manufacturing difficulties, low aberration-correcting ability, and sensitivity to manufacturing errors.
Innovation Solution
An image pickup lens comprising three lens blocks with a specific power arrangement, where each block is connected to a parallel flat plate substrate, and the lens blocks are formed of different materials, with the first lens block having positive power and the second having negative power, allowing for aberration correction and reduced sensitivity to manufacturing errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a diffractive surface is used in the image pickup lens, then compactness can be improved, but manufacturing difficulty increases and optical quality deteriorates due to wavelength-dependent diffraction efficiency and ghost images
Solution Approach 1:
The patent removes the diffractive surface from the lens system entirely. Instead of using a diffractive optical element, the invention employs conventional refractive lens surfaces that can be manufactured using standard molding techniques, thereby eliminating manufacturing complexity while maintaining compact lens design through optimized refractive power distribution.
Solution Approach 2:
The patent adopts conventional plastic lens materials and standard optical surfaces that are inexpensive to manufacture through mass production molding processes. This approach replaces expensive and difficult-to-manufacture diffractive surfaces with affordable, easily replicable refractive surfaces suitable for mass production.
2Volume of moving object
If the lens block at the closest position to the object has excessively strong power to achieve compactness, then total optical length is reduced, but sensitivity to manufacturing errors increases and optical quality deteriorates
Solution Approach 1:
The patent divides the lens system into three separate lens blocks with distributed optical powers. The first lens block has positive power, the second has negative power, and the third has positive power. This segmentation allows the total optical power to be distributed across multiple elements rather than concentrated in one element, reducing sensitivity to manufacturing errors while achieving compact overall length.
Solution Approach 2:
The patent optimizes the power distribution parameters of the three lens blocks by satisfying specific conditional expressions for focal lengths and power ratios. By carefully controlling these parameters, the system achieves compact size while maintaining low sensitivity to manufacturing tolerances through balanced power distribution.
3Device complexity
If only two lens blocks are used to simplify the structure, then device complexity is reduced, but aberration-correcting ability becomes insufficient for high-pixel image pickup elements
Solution Approach 1:
The patent employs three lens blocks instead of two, with each block containing multiple lens elements. This segmentation provides sufficient degrees of freedom to correct various types of optical aberrations including spherical aberration, coma, and chromatic aberration, thereby achieving the aberration-correcting ability required for high-pixel image pickup elements while maintaining reasonable structural complexity.
4Productivity
If conventional lens structures are used to maintain ease of manufacture, then mass productivity is achieved, but heat resistance is insufficient to withstand reflow processing during mounting
Solution Approach 1:
The patent uses plastic lens materials that possess both moldability for mass production and sufficient heat resistance to withstand reflow processing. The composite lens block structure combines multiple plastic elements with different thermal and optical properties, achieving both manufacturability and thermal stability required for mounting processes.
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 enables a compact image pickup lens with improved aberration correction and reduced sensitivity to manufacturing errors, facilitating mass production and heat resistance, suitable for camera modules in mobile terminals.
Implementation Method 1
an image pickup lens which includes at least three lens blocks BK1 to BK3... the first lens block BK1 has a positive power, and the second lens block BK2 has a negative power
Data Source
AI summary
Disclosed is an image pickup lens (LN) including at least three lens blocks (BK) each equipped with a lens substrate (LS) being a parallel flat plate, and a lens or lenses (L) having a positive or negative power and being connected to at least one of an object-side surface and an image-side surface of the lens substrate (LS). In the image pickup lens (LN), a first lens block (BK1) arranged at a closest position to an object side has a positive powder, a second lens block (BK2) arranged at an image side of the first lens block (BK1) has s negative power, and predetermined conditional expressions are satisfied, whereby the image pickup lens capable of being easily produced at a low cost and having a high performance and a compact size can be provided.