Zoom Lens Autofocus Auxiliary Light Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In cameras with a zoom function, the precision of autofocus (AF) is compromised due to insufficient light quantity and irradiation range of auxiliary light, which varies with the zoom position of the taking lens.
Innovation Solution
An imaging device that controls the emitted light quantity and irradiation range of auxiliary light based on the zoom position of the photographic optical system, using methods such as adjusting the applied voltage, current flow, number of light sources, or combination of irradiation lenses to maintain optimal AF precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the zoom position of the taking lens is changed, then the photographing range and F value are changed, but the light quantity of the AF auxiliary light becomes insufficient
Solution Approach 1:
The patent applies dynamics by making the AF auxiliary light quantity and irradiation angle adjustable according to the zoom position. The control unit dynamically changes the light output based on the current zoom state, ensuring adequate illumination for autofocus across all focal lengths. This resolves the contradiction by adapting the light system to the changing optical conditions rather than using a fixed configuration.
Solution Approach 2:
The patent changes physical parameters of the AF auxiliary light system - specifically the light quantity (luminous flux) and irradiation angle - based on the zoom position parameter. When the zoom lens is at different focal lengths, the control unit adjusts these parameters to maintain optimal autofocus performance. This directly addresses the contradiction by varying light parameters to compensate for changes in the photographing range and F value.
2Adaptability or versatility
If the zoom position of the taking lens is changed, then the photographing range and F value are changed, but the irradiation range of the AF auxiliary light becomes insufficient
Solution Approach 1:
The patent makes the irradiation angle of the AF auxiliary light dynamically adjustable based on zoom position. The control unit changes the angle at which light is projected onto the subject according to the current focal length, ensuring the illuminated area matches the photographing range. This dynamic adjustment resolves the contradiction between zoom adaptability and sufficient irradiation range.
Solution Approach 2:
The patent changes the irradiation angle parameter of the AF auxiliary light system in response to zoom position changes. By adjusting this angular parameter, the system ensures that the light covers the appropriate area for autofocus at each focal length, resolving the contradiction between adaptability and irradiation range sufficiency.
3Device complexity
If a fixed AF auxiliary light system is used, then the device complexity is reduced, but the AF precision deteriorates at certain zoom positions
Solution Approach 1:
The patent introduces dynamic control of the AF auxiliary light system based on zoom position detection. The control unit receives zoom position information and automatically adjusts light quantity and angle accordingly. This dynamic approach maintains high AF precision across all zoom positions while keeping the control mechanism relatively simple, resolving the contradiction between complexity and precision.
Solution Approach 2:
The patent implements a feedback mechanism where the control unit monitors the zoom position and uses this information to adjust the AF auxiliary light parameters. This closed-loop control ensures that the light system adapts to changing optical conditions, maintaining precision without requiring complex manual adjustment mechanisms. The feedback from the zoom position sensor drives the automatic light adjustment.
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
Improves the precision of autofocus operations by ensuring consistent and appropriate auxiliary light conditions across different zoom positions, enhancing the accuracy of focusing.
Implementation Method 1
an auxiliary light source emitting an auxiliary light and which irradiates the auxiliary light to a subject
Implementation Method 2
which makes the auxiliary light reflected by the subject incident on the photographic optical system to perform focusing operation
Data Source
AI summary
The present invention provides an imaging device including a photographic optical system having a zoom function, an auxiliary light irradiation device which includes an auxiliary light source emitting auxiliary light and which irradiates the auxiliary light towards a subject, a range finding device which makes the auxiliary light reflected by the subject incident on the photographic optical system to perform a focusing operation, and an auxiliary light control device which controls at least one of emitted light quantity of the auxiliary light and irradiation range of the auxiliary light in accordance with a zoom position of the photographic optical system.