Zoom-Focus Lens Timing Control for Precise Position Synchronization
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Solution Overview
Problem
Conventional imaging devices lack precision in controlling lens positions during zoom drives, which affects the quality of live view and movie images, and do not effectively prevent interference between lens groups.
Innovation Solution
A lens control device and method that utilize stepping motors for zoom and focus lenses, with a processor setting drive times based on a specified control unit time, ensuring at least one motor is driven at a constant rate, and dividing the drive period into multiple periods to maintain precise lens positioning and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional imaging devices drive multiple lens groups simultaneously with individual motors, then zoom and focus operations can be performed, but lens position precision deteriorates and interference between lens groups occurs
Solution Approach 1:
The patent implements feedback control by detecting actual lens positions during zoom drive and comparing them with target positions. Based on this feedback, the system adjusts drive commands for individual lens groups to ensure they reach target positions simultaneously, preventing interference and improving positioning precision.
Solution Approach 2:
The patent merges the control of multiple lens groups under a unified control system that coordinates their movements. By integrating position detection and centralized control logic, the system ensures synchronized operation of zoom and focus lenses, eliminating interference that occurs with independent control.
2Object-generated harmful factors
If lens groups are driven to approach specified positions during zoom, then interference between lenses is prevented, but live view and movie image quality deteriorates due to positioning errors
Solution Approach 1:
The system continuously monitors actual lens positions during zoom operations and uses this feedback to correct positioning errors. By comparing detected positions with target positions and adjusting drive commands accordingly, the system maintains both interference prevention and high positioning accuracy for improved image quality.
Solution Approach 2:
The patent implements dynamic adjustment of lens drive parameters during zoom operations. The control system adapts drive speeds and timing based on real-time position feedback, allowing lens groups to reach target positions accurately while maintaining coordinated movement to prevent interference.
3Measurement precision
If stepping motors are driven at constant rate with divided periods, then lens positioning precision is improved, but control system complexity increases
Solution Approach 1:
The patent segments the zoom drive operation into multiple periods with different drive rates. By dividing the constant speed period into sub-periods with alternating drive times, the system achieves higher positioning precision through finer control granularity while managing complexity through structured temporal segmentation.
Solution Approach 2:
The system uses periodic alternating drive times (first time and second time) within constant speed periods to achieve precise lens positioning. This periodic variation in drive parameters allows the system to compensate for positioning errors while maintaining a relatively simple control structure based on time-division multiplexing.
Data Source
AI summary
A lens control device, comprising a first stepping motor that drives a zoom lens contained in the photographing lens, a second stepping motor that drives a focus lens contained in the photographing lens, and a processor that controls the first stepping motor and the second stepping motor, whereby, within a given section in which the zoom lens and the focus lens are driven, there is a period in which at least one of the first stepping motor and the second stepping motor is driven at a constant rate, and the processor makes a time, required to move the specified section with a specified number of pulses, a specified time.