Camera Module Piezoelectric Focus Adjustment
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Solution Overview
Problem
Conventional camera modules suffer from defocusing issues due to uncontrollable shrinkage of thermosetting glue and varying expansion/deformation ratios of optical lenses, leading to a fixed-focus structure that cannot adjust focal length, resulting in poor imaging quality.
Innovation Solution
Incorporating a piezoelectric plate between the lens module and the sensing chip, which deforms in response to electric power to adjust the spacing distance and maintain focus, allowing for precise focal length matching and improved imaging quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermosetting glue is used to bond the lens holder and substrate, then the lens module and substrate are combined together and particles are prevented from entering, but the glue shrinks uncontrollably after baking causing defocusing
Solution Approach 1:
The patent changes the physical-chemical parameters of the bonding material from thermosetting glue to UV-curing adhesive. The UV-curing adhesive undergoes polymerization upon UV irradiation without significant shrinkage, maintaining the spacing distance between lens group and sensing chip. This resolves the contradiction by providing both strong bonding and precise spacing control.
Solution Approach 2:
The patent replaces the thermal curing process (heat-based) with UV light-based curing. The UV-curing adhesive cures through photopolymerization when exposed to UV light, eliminating the thermal shrinkage issues associated with thermosetting glue. This substitution maintains bonding strength while preventing spacing distance changes.
2Adaptability or versatility
If different optical lenses are made of different materials, then various optical requirements are met, but the lenses have different expansion/deformation ratios at the same temperature causing defocusing
Solution Approach 1:
The patent applies preliminary action by pre-adjusting the spacing distance between the lens group and sensing chip before final assembly. The spacing is designed to account for expected thermal expansion differences, and the UV-curing adhesive locks this pre-adjusted spacing in place. This preliminary positioning ensures focus is maintained despite different lens material expansion ratios.
Solution Approach 2:
The patent changes the curing mechanism from thermal to UV-based, eliminating temperature-induced differential expansion during the bonding process. The UV-curing adhesive cures at room temperature or low temperature through photopolymerization, preventing thermal expansion mismatches between different lens materials and maintaining stable spacing.
3Manufacturing precision
If the spacing distance between lens group and sensing chip is changed to correct defocusing, then focus can be adjusted, but the fixed-focus structure cannot change focal length
Solution Approach 1:
The patent introduces a driving chip that can dynamically adjust the position of the lens holder relative to the sensing chip by actuating the support ribs. This dynamic adjustment mechanism allows the camera module to change focal length and adapt to different focusing requirements, transforming the fixed-focus structure into an adjustable one while maintaining precise focus control.
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 camera module achieves sharp images by dynamically adjusting the spacing distance between the lens group and the sensing chip, overcoming defocusing problems and enabling improved imaging quality in portable and vehicular devices while maintaining small size and light weightiness.
Implementation Method 1
a piezoelectric plate is arranged between the substrate and the lens module. When an electric power is provided to the piezoelectric plate, the piezoelectric plate is subjected to deformation
Data Source
AI summary
A camera module includes a substrate, a sensing chip, a lens module and a piezoelectric plate. The sensing chip is electrically connected with the substrate. The sensing chip includes a sensing region. The sensing chip is covered by the lens module. The sensing chip is arranged between the substrate and the lens module. When an external light beam passes through the lens module and projected on the sensing region, the sensing chip generates an image. The piezoelectric plate is arranged between the substrate and the lens module. When an electric power is provided to the piezoelectric plate, the piezoelectric plate is subjected to deformation, so that the lens group focuses on the sensing region. The present invention also provides a calibration method for the camera module.