Autofocus Adapter Light Split Unit for Compact Focus Detection
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Solution Overview
Problem
Existing autofocus systems for imaging lenses face challenges in compactness and cost-effectiveness, particularly when integrating focus state detection, as they often require a relay lens system that prevents the use of extender optical systems and results in increased overall length.
Innovation Solution
A compact autofocus adapter system that includes a light split unit and separate optical systems for image formation and focus state detection, allowing for focus state detection without a relay optical system, enabling attachment to existing imaging lenses with extender systems and maintaining compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a relay lens system is used for focus state detection, then focus detection capability is improved, but the overall length increases and extender optical systems cannot be used
Solution Approach 1:
The optical system is segmented into separate functional modules: a first optical system for image formation and a second optical system for focus state detection. These systems operate independently and can be attached to existing imaging lenses without requiring a relay lens system, thereby maintaining compactness while enabling focus detection.
Solution Approach 2:
A light split unit is introduced as an intermediary component that divides the incident light into two separate optical paths: one for image formation and another for focus state detection. This allows both functions to coexist without requiring a relay lens system, solving the contradiction between compactness and focus detection capability.
2Measurement precision
If a relay optical system is incorporated for focus state detection, then focus detection is enabled, but the system becomes complex and costly
Solution Approach 1:
The system is divided into distinct optical paths: a first optical system for image formation and a second optical system for focus state detection. Each system can be independently designed and attached to existing imaging lenses, reducing overall system complexity and cost compared to integrated relay lens systems.
Solution Approach 2:
The adapter system is designed to be universally applicable to existing imaging lenses with extender optical systems. The light split unit and separate optical systems can be attached to any compatible lens, providing multi-functionality without requiring complex custom designs for each application.
3Measurement precision
If light is split for focus state detection, then focus detection capability is improved, but light flux may be shaded reducing optical performance
Solution Approach 1:
A light split unit is introduced as an intermediary component that carefully divides the incident light into two separate optical paths. By positioning and designing this component optimally, the system achieves effective focus state detection while minimizing light flux shading and maintaining adequate optical performance for both image formation and detection functions.
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 efficient autofocus control of imaging lenses while maintaining compactness and reducing costs, as it splits the light flux effectively for focus state detection without shading and uses a positive lens group configuration to minimize optical performance degradation.
Implementation Method 1
a light split unit (a first split unit) being placed on the optical axis of the imaging lens (a first optical axis) when the autofocus adapter is attached for splitting subject light passing through the imaging lens into subject light for image formation (second subject light) and the focus state detection subject light
Implementation Method 2
a first lens group having negative power as a whole and placed on the side of an object with respect to the light split unit; and a second lens group having positive power as a whole and placed on the side of an image with respect to the light split unit
Data Source
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AI summary
An autofocus adapter (10) is provided and includes a first optical system (10A) placed on the optical axis (Z1) of an imaging lens (20) and a focus state detection adapter second optical system (10B) placed on an optical axis (Z2) different from that of the imaging lens. The imaging adapter optical system (10A) has a light split prism (P1) for splitting subject light passing through the imaging lens into imaging subject light and the focus state detection subject light, a first lens group (L1) having negative power and placed on the object side with respect to the light split prism, and a second lens group (L2) having a positive power as a whole and placed on the image side with respect to the light split prism.