Camera Tester Evaluating Fixed Focus Lens Phase Difference Range
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Solution Overview
Problem
Existing camera testing technologies face challenges in efficiently evaluating the focusing characteristics of fixed focus (FF) modules without the burdens of high cost, time, and component procurement issues associated with auto-focus (AF) modules, particularly due to the need for complex and costly components like voice coil motors (VCM) for auto focusing.
Innovation Solution
A camera testing device that evaluates the focusing characteristics of FF modules by using a method involving a first and second chart positioned at different distances from the camera, with a camera tester aligning the camera, measuring blur, and calculating the phase difference range (PDR) based on a circle of confusion (CoC) model, allowing for cost-effective and time-efficient testing without the need for AF module components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If AF module components (VCM) are used for testing focusing characteristics, then focusing evaluation capability is improved, but testing cost and device complexity increase
Solution Approach 1:
The patent extracts the essential function of focusing evaluation from the complex AF module system by removing the VCM actuator and using only the lens module with fixed focus capability. The testing device uses a first chart at infinity distance and a second chart at macro distance to evaluate focusing characteristics without requiring the full AF module assembly, thereby simplifying the device structure while maintaining measurement capability.
Solution Approach 2:
The patent creates a simplified testing scenario that copies the essential focusing evaluation function without replicating the entire AF module. By using a fixed focus lens module with two charts at different distances, the device replicates the focusing characteristic measurement capability without needing the expensive VCM components, achieving cost-effective testing through functional copying.
2Measurement precision
If AF module components are procured for testing, then focusing test capability is improved, but procurement time and cost increase
Solution Approach 1:
The patent performs preliminary setup by positioning the first chart at infinity distance and the second chart at macro distance before conducting the actual focusing evaluation. The lens module is pre-configured with fixed focus settings, eliminating the need for time-consuming VCM calibration and assembly preparation. This preliminary configuration enables immediate testing without the procurement and setup delays associated with AF module components.
3Measurement precision
If complex testing procedures with AF modules are used, then focusing evaluation accuracy is improved, but testing process complexity increases
Solution Approach 1:
The patent segments the focusing evaluation process into two distinct measurement stages: first, capturing an image of the chart at infinity distance to establish baseline focus; second, capturing an image of the chart at macro distance to measure phase difference. This segmentation simplifies the操作流程 by breaking down the complex AF module testing into manageable steps with clear measurement criteria, making the procedure easier to execute while maintaining 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
Enables efficient evaluation of focusing characteristics of FF modules, reducing testing costs and time by eliminating the need for AF module-related components and procedures, while providing a reliable assessment of phase difference range.
Implementation Method 1
setting a camera to align the camera and a first chart structured to provide a first scene for testing such that the camera is focused on the first chart disposed at a first distance from the camera
Implementation Method 2
measuring a blur in an image of a second chart captured at a second distance from the camera
Data Source
AI summary
A method for testing a focusing characteristic of a camera may include setting a camera to align the camera and a first chart structured to provide a first scene for testing such that the camera is focused on the first chart disposed at a first distance from the camera, measuring a blur in an image of a second chart captured at a second distance from the camera, the second chart being structured to provide a second scene for testing, and evaluating a phase difference range (PDR) of the camera based on the measured blur and a blur calculated through a circle of confusion (CoC) model.