Imaging Device Lens Barrel Thread Groove Focus Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging devices face challenges in focus adjustment and optical axis displacement due to variations in screw fastening force and thermal expansion, which require careful assembly and can lead to inaccuracies.
Innovation Solution
The imaging device incorporates a lens barrel with a thread groove in its outer periphery and a housing with a threaded portion, allowing for precise focus adjustment and reduced optical axis displacement by positioning the rotation center close to the image-side principal point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If screw fastening is used to mount the imaging element, then the imaging element can be securely fixed, but the focus position varies and the optical axis may tilt due to uneven fastening force
Solution Approach 1:
The patent extracts the imaging element from the traditional screw-fastened substrate mounting and relocates it to a dedicated imaging element holder. This separation allows the holder to provide precise positioning while the substrate maintains structural support, eliminating the conflict between strong fixation and precise focus positioning.
Solution Approach 2:
The imaging element holder acts as an intermediary component between the substrate and the imaging element. It provides a stable mounting interface with precise dimensional control, serving as a mediator that ensures both secure fixation and accurate focus positioning without the drawbacks of direct screw fastening.
2Ease of manufacture
If traditional adhesive films are used to fix the lens, then assembly is simplified, but thermal expansion causes focus shift and optical axis displacement
Solution Approach 1:
The patent changes the material parameter selection criterion from general adhesion to matching thermal expansion coefficients. By selecting adhesive materials whose thermal expansion coefficients closely match those of the lens and holder, the system maintains dimensional stability under temperature variations while still providing easy assembly through adhesive bonding.
3Stability of the object's composition
If the lens is held firmly in the lens holder, then position stability is improved, but optical axis displacement occurs due to thermal expansion differences
Solution Approach 1:
The patent modifies the material selection parameters by choosing materials with matched thermal expansion coefficients. This parameter change allows the lens holder and lens to expand and contract together under temperature variations, maintaining both firm holding and optical axis stability without the harmful displacements caused by differential thermal expansion.
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
This configuration facilitates easier focus adjustment and minimizes optical axis displacement, improving the imaging device's accuracy and reliability, especially in varying temperature conditions.
Implementation Method 1
a rotational displacement caused by thermal expansion or contraction of the adhesive member 151 due to temperature variation
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
An imaging device includes a lens barrel in which a plurality of lenses are held and that has a thread groove in a cylindrical outer periphery thereof; an imaging element that captures a subject image incident on the imaging element through the lenses; a housing that holds the imaging element and that includes a threaded portion configured to engage with the thread groove in the outer periphery of the lens barrel; and an adhesive member positioned between the thread groove in the outer periphery of the lens barrel and the threaded portion of the housing. The thread groove is provided in a range including a position at which a principal plane of an optical system including the plurality of lenses crosses the outer periphery of the lens barrel.