Focusing Control Device Dynamic Range Adjustment
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Solution Overview
Problem
Existing imaging devices face challenges in maintaining focus on a target subject, especially when the subject moves rapidly, as existing focusing control methods do not effectively manage the movement of the focus lens to prevent other subjects from being in focus.
Innovation Solution
A focusing control device and method that utilize signal detection sections to control the movement of a focus lens within a defined range, adjusting the movement allowable range based on phase difference measurements to ensure continuous focus on the target subject, even during rapid movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the focus lens is prevented from moving when defocus amount changes are large, then other subjects are prevented from being in focus, but the target subject becomes out of focus when it moves rapidly
Solution Approach 1:
The patent dynamically adjusts the movement allowable range of the focus lens based on the detected defocus amount changes. When defocus changes are small, the movement range is restricted to prevent focusing on other subjects. When defocus changes exceed a threshold indicating rapid subject movement, the movement range is expanded to allow the focus lens to track the moving target subject, thus resolving the contradiction between focus accuracy and tracking speed
Solution Approach 2:
The system changes the parameter of movement allowable range based on the detected defocus amount. By comparing the current defocus amount with the previous defocus amount, the system determines whether to restrict or expand the focus lens movement range, enabling adaptive response to different subject movement scenarios
2Stability of the object's composition
If the focus lens movement is continuously restricted to prevent other subjects from being in focus, then focus stability is improved, but the system cannot respond to rapidly moving target subjects
Solution Approach 1:
The system transitions from a static focus control approach to a dynamic one by continuously monitoring defocus amount changes and adjusting the movement allowable range accordingly. This enables the system to maintain focus stability under normal conditions while adapting to rapid subject movements when they occur
Solution Approach 2:
The system uses feedback from defocus amount detection to control focus lens movement. By continuously detecting the defocus amount and comparing it with previous values, the system receives feedback about subject movement and adjusts the movement allowable range to maintain appropriate 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 solution allows for accurate and continuous focus on the target subject while preventing other subjects from being in focus, enhancing the imaging device's ability to capture clear images during dynamic scenes.
Implementation Method 1
a phase difference measurement unit that measures a phase difference amount between a first signal group output from the plurality of first signal detection sections and a second signal group output from the plurality of second signal detection sections
Data Source
AI summary
A focusing control device includes: a plurality of signal detection sections that receives luminous fluxes passing through an imaging optical system including a focus lens capable of moving in an optical axis direction in a first range and detects signals corresponding to light reception amounts; a movement allowable range control unit that controls a movement allowable range in which movement of the focus lens set in the first range is allowed; and a lens driving control unit that moves the focus lens within the movement allowable range controlled by the movement allowable range control unit based on a signal group output from the plurality of signal detection sections.