Lens Barrel Wobble Autofocus Mechanism
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Solution Overview
Problem
Conventional camera lens barrels with separate zoom and focus lens groups for capturing still and moving pictures result in increased noise and power consumption, leading to shorter imaging time and larger barrel size.
Innovation Solution
A lens barrel with a first and second zoom/focus lens group, each driven by a dedicated actuator, and a drive controller that independently controls these actuators to minimize auto-focusing operations during moving picture imaging by wobbling only the lightest lens group along the optical axis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If separate zoom and focus lens groups are used to vary focal distance and imaging distance, then the lens barrel becomes larger, but if multiple lens groups are used with individual actuators for compactness, then noise increases and power consumption increases
Solution Approach 1:
The lens system is divided into multiple lens groups (first zoom/focus lens group and second zoom/focus lens group), each capable of independent movement controlled by separate actuators. This segmentation allows selective operation of individual lens groups during auto-focusing, enabling compact overall design while controlling noise by activating only one lens group at a time for wobbling operations.
2Measurement precision
If multiple lens groups are operated simultaneously for auto-focusing, then accurate focusing can be achieved, but power consumption increases and imaging time decreases
Solution Approach 1:
The drive controller implements periodic wobbling action by reciprocating only the first zoom/focus lens group in the optical axis direction during auto-focusing. This periodic reciprocating movement allows focal position detection through contrast variation, achieving accurate auto-focusing while minimizing the number of moving components and reducing power consumption compared to simultaneous operation of multiple lens groups.
3Measurement precision
If multiple lens groups are operated simultaneously for auto-focusing, then focusing accuracy improves, but noise increases that may be recorded during moving picture imaging
Solution Approach 1:
The wobble operation is extracted from the second zoom/focus lens group and assigned exclusively to the first zoom/focus lens group. By taking out the wobbling function from one lens group and assigning it to another, the system achieves focal position detection through contrast variation while minimizing the number of simultaneously operating lens groups, thereby reducing operating noise that could be recorded during moving picture imaging.
Data Source
AI summary
A lens barrel comprises a first zoom/focus lens group and a second zoom/focus lens group configured to respectively vary a focal distance and imaging distance by moving in an optical axis, a first actuator configured to drive the first zoom/focus lens group, a second actuator configured to drive the second zoom/focus lens group, and a drive controller configured to independently control the first actuator and the second actuator. The drive controller is configured to wobble the first zoom/focus lens group by reciprocating only the first zoom/focus lens group out of the first and second zoom/focus lens groups in a optical axis direction.