Digital Camera Focusing Control for Still and Video Modes
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Solution Overview
Problem
Digital cameras face challenges in seamlessly transitioning between still image and moving image shooting modes, particularly in focusing operations, which affect the quality and usability of both types of photography.
Innovation Solution
A digital camera design that incorporates a mirror member to split the subject light beam, allowing for different focusing operations in still image and moving image modes by varying the focusing tolerance and driving speed of the focusing optical system, and uses phase-difference AF methods for accurate focusing and constant angle-of-view maintenance during moving image recording.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the same focusing operation is used for both still image and moving image modes, then the camera structure remains simple, but the focusing quality and user experience deteriorate due to inability to optimize for each mode
Solution Approach 1:
The patent implements dynamic focusing operations by detecting the shooting mode (still image or moving image) and automatically selecting appropriate focusing parameters. The focusing part varies focusing tolerance range and driving speed based on mode detection, allowing the system to adapt its behavior without requiring manual intervention or complex physical reconfiguration.
Solution Approach 2:
The patent changes focusing parameters such as focusing tolerance range and driving speed according to the shooting mode. By modifying these parameters dynamically, the system achieves optimized focusing performance for each mode while maintaining a relatively simple overall structure, resolving the contradiction between operational optimization and device complexity.
2Ease of operation
If the focusing tolerance range is widened for moving image mode, then the ease of operation improves, but the focusing precision deteriorates
Solution Approach 1:
The system dynamically adjusts focusing tolerance range based on the detected shooting mode. During moving image recording, the focusing tolerance range is widened to facilitate easier tracking of moving subjects, while maintaining narrower tolerance during still image mode for precise focusing. This dynamic adaptation resolves the contradiction between ease of operation and precision.
Solution Approach 2:
The patent implements parameter changes by varying the focusing tolerance range according to shooting mode. This allows the system to prioritize ease of operation during moving image mode while maintaining precision during still image mode, effectively resolving the trade-off between these two requirements.
3Productivity
If the driving speed of focusing optical system is increased, then the productivity improves, but the focusing quality deteriorates due to potential overshoot or vibration
Solution Approach 1:
The system dynamically adjusts focusing driving speed based on shooting mode detection. During still image mode, high driving speed is used to quickly achieve focus. During moving image mode, the driving speed is reduced to prevent overshoot and vibration, ensuring stable focusing quality. This dynamic control resolves the contradiction between productivity and precision.
Solution Approach 2:
The patent implements parameter changes by varying the driving speed of the focusing optical system according to the detected mode. This allows the system to maximize productivity during still image shooting while maintaining focusing quality during moving image recording, effectively resolving the trade-off between speed and precision.
4Adaptability or versatility
If the mirror member is positioned to reflect light for distance measurement, then the adaptability improves, but the optical path complexity increases
Solution Approach 1:
The mirror member is designed to serve multiple functions: it reflects light for distance measurement during moving image mode and can be retracted or repositioned for still image mode. This multi-functionality allows a single component to support both shooting modes, improving adaptability while minimizing the increase in optical path complexity.
Solution Approach 2:
The patent implements dynamic positioning of the mirror member based on shooting mode detection. The mirror can be repositioned or retracted as needed, allowing the system to adapt its optical path configuration dynamically. This dynamic adjustment enables mode-specific optimization without permanently increasing overall system complexity.
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
Enables easy-to-use digital cameras capable of capturing high-quality both still and moving images by optimizing focusing operations and maintaining a constant angle of view during moving image shooting, improving user experience and image quality.
Implementation Method 1
a mirror member arranged in an optical path of a photographing lens to reflect part of a subject light beam passing through the photographing lens and transmit the remaining part of the subject light beam
Implementation Method 2
an imaging part for receiving the subject light beam transmitted through the mirror member to output a subject image signal
Implementation Method 3
a distance measurement part for receiving the subject light beam reflected by the mirror member to detect a defocus amount of the photographing lens
Data Source
AI summary
A digital camera is disclosed, which has a still image shooting mode and a moving image shooting mode, and performs different focusing operations between the still image shooting mode and the moving image shooting mode. According to present invention, the range of focusing tolerance or the driving speed of a focusing optical system can vary between the still image shooting mode and the moving image shooting mode such as to set the range of focusing tolerance wider or the driving speed of the focusing optical system slower in the moving image shooting mode.