Interchangeable Lens Variable Focusing Speed Control
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Solution Overview
Problem
Existing interchangeable lens systems face challenges in efficiently driving focusing optical systems and communicating image plane movement coefficients to camera bodies, leading to suboptimal focusing accuracy and speed.
Innovation Solution
An interchangeable lens system with a movable focusing optical system and a communication module that transmits specific image plane movement coefficients to the camera body, allowing for precise control of focusing speed and accuracy based on lens positions, using ultrasonic motors and encoder feedback for precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the focusing optical system is driven at high speed, then focusing speed is improved, but focusing accuracy deteriorates
Solution Approach 1:
The patent applies dynamics by making the driving speed of the focusing optical system variable rather than constant. The driving speed is dynamically adjusted based on the current lens position and the specific focusing stage (rough focus vs. precise focus), allowing high speed during rough focusing and low speed during precise focusing, thus resolving the contradiction between focusing speed and accuracy
Solution Approach 2:
The patent segments the focusing process into multiple stages: rough focusing stage and precise focusing stage. Each stage uses different driving speeds appropriate to its requirements. The rough focusing stage uses higher speed to quickly bring the lens near the focus position, while the precise focusing stage uses lower speed to achieve accurate focus, thereby resolving the speed-accuracy contradiction
2Device complexity
If a single image plane movement coefficient is used for all lens positions, then device complexity is reduced, but focusing accuracy deteriorates
Solution Approach 1:
The patent applies local quality by using different image plane movement coefficients for different lens positions. Instead of using a single universal coefficient, the system selects appropriate coefficients based on the current lens position range, ensuring high focusing accuracy for each specific position while managing complexity through structured coefficient tables and position-based selection
3Productivity
If the focusing optical system is driven at high speed, then productivity is improved, but focusing accuracy deteriorates
Solution Approach 1:
The patent applies periodic action by alternating between high-speed driving periods (rough focusing) and low-speed driving periods (precise focusing). This periodic variation in driving speed allows the system to maintain high overall productivity while ensuring accurate focus is achieved in the low-speed phase, resolving the contradiction between efficiency and accuracy
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
Enhances focusing accuracy and speed by adjusting driving speed based on real-time image plane movement coefficients, ensuring optimal focus detection and image quality across varying lens positions.
Implementation Method 1
using ultrasonic motors and encoder feedback for precise positioning
Implementation Method 2
using ultrasonic motors and encoder feedback for precise positioning
Data Source
AI summary
An interchangeable lens attachable to a camera body, the interchangeable lens including: a focusing optical system configured to vary a focal position of the interchangeable lens; and a transmitter configured to transmit a first value and a second value to the camera body, the first value indicating a relationship between an amount of movement of the focusing optical system and an amount of movement of an image plane at a position to which the focusing optical system has moved, the second value indicating a relationship between an amount of movement of the focusing optical system and an amount of movement of the image plane, the second value being equal to or smaller than the first value.