Lens Barrel Position Detection via Optical Intermediary
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Solution Overview
Problem
Conventional lens barrels with retractable lens retaining frames face challenges in accurately detecting position changes and displacements, leading to complexity in mechanisms for detecting optical axis alignment during transitions between collapsed and photographing states.
Innovation Solution
A lens barrel design incorporating a telescopic cylinder, retractable lens retaining frames, and a position detector system with a cam portion and lead screw mechanism to accurately detect and align optical axes, enabling precise movement and alignment of lens groups for minimized size and improved usability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a retractable lens retaining frame is used to reduce lens barrel thickness, then the thickness of the imaging device is reduced, but it becomes difficult to accurately grasp position changes and displacement of the lens retaining frame
Solution Approach 1:
A detector is introduced as an intermediary component to accurately detect the position of the lens retaining frame. The detector comprises a light source, light-receiving element, and processing unit that work together to provide precise position information without adding mechanical complexity to the retractable lens mechanism.
Solution Approach 2:
The patent replaces complex mechanical position detection mechanisms with an optical detection system. Instead of using mechanical switches or encoders that would increase device complexity, the invention uses light-based detection to determine lens retaining frame position, thereby maintaining measurement precision while avoiding mechanical complexity.
2Measurement precision
If a mechanism for detecting lens position is added, then position detection accuracy is improved, but device complexity increases
Solution Approach 1:
The detector acts as a simple intermediary that uses optical fields rather than complex mechanical linkages. The light source and light-receiving element create an optical measurement system that is simpler than traditional mechanical position sensors, reducing overall device complexity while maintaining detection accuracy.
Solution Approach 2:
The invention changes the detection parameter from mechanical position to optical signal transmission. By detecting changes in light intensity or position rather than mechanical displacement, the system achieves accurate lens position detection with a simpler, more compact detection mechanism.
3Length of stationary object
If the lens retaining frame is retracted out of the optical axis, then the thickness of the imaging device is reduced, but it becomes difficult to accurately grasp optical axis alignment during transitions
Solution Approach 1:
The detector serves as an intermediary that continuously monitors the optical axis alignment by detecting the position of the lens retaining frame relative to the optical axis. This allows the system to accurately grasp alignment status during transitions between retracted and extended states without adding mechanical alignment mechanisms.
Solution Approach 2:
The detection system provides feedback about the lens retaining frame position and optical axis alignment status to the control system. This feedback enables real-time monitoring and adjustment, ensuring accurate alignment during transitions while maintaining the retractable design for thickness reduction.
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 allows for accurate detection of position changes and alignments, facilitating efficient operation from activation to completion of photographing, thus enhancing ease of use and minimizing device size without increasing thickness.
Implementation Method 1
a lead screw configured to advance and retreat the retractable lens retaining frame in a direction substantially extending parallel with the optical axis of the other lens group
Implementation Method 2
a female screw member screwed on the lead screw and capable of being advanced and retracted by rotation of the lead screw
Implementation Method 3
the retractable lens retaining frame including a cam portion configured to change a position of the retractable lens retaining frame between the retracted position and the photographing position
Data Source
AI summary
A lens barrel capable of accurately detecting a position of a retractable lens retaining frame. A frame female member for rotating a frame around a lead screw and driving the frame in forward and backward directions along the lead screw is formed with a T-shared protruded member as a detected portion located at a position opposite a rotation-preventing projection. The T-shared member structures a position of the frame together with a transmissive photo-interrupter, to decide a reference position in a retracted state of the frame and for an optical axis entrance completed position of the frame at a time when a transition has changed from a retracted state to a photographable state, and detects a distance from the reference position of the frame or a position of the frame in the photographable state in which a focal distance during wide-angle photographing and telephoto photographing is changed.