Compact MTF Evaluation Optics for Short-Footprint Camera Testing

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Solution Overview

Problem

Existing methods for evaluating the modulation transfer function (MTF) of cameras require a large testing footprint due to the significant hyper-focal distance of many cameras, making them impractical for compact systems, and often result in uneven target illumination.

Innovation Solution

A compact MTF evaluation system using a combination of collimated target sources and image analysis components, which create a virtual image at a reduced distance, allowing for MTF calculation with a significantly smaller footprint while maintaining image quality comparable to full-size systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a conventional processor architecture is used to evaluate transfer functions, then computational capability is provided, but the system occupies a large amount of chip area and consumes excessive power

Engineering Contradiction:
Improvepower consumptionVSAvoidprocessor architecture complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent replaces conventional digital processor architectures with an analog computing system that directly performs transfer function evaluations using continuous physical signals. This substitution eliminates the need for complex digital logic circuits, reducing both power consumption and chip area while maintaining computational capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the fundamental operating parameters from digital discrete values to analog continuous signals. By using analog voltages and currents to represent data and perform computations, the system achieves the same computational function with significantly reduced complexity and power requirements compared to digital processors.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If high-precision floating-point arithmetic is implemented, then computational accuracy is improved, but the device complexity and resource requirements increase

Engineering Contradiction:
Improvecomputational accuracyVSAvoidarithmetic unit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex digital floating-point arithmetic units with analog computational circuits that perform mathematical operations directly on continuous signals. This substitution maintains computational accuracy for transfer function evaluations while dramatically reducing the complexity and resource requirements of the arithmetic units.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If a fixed-function processor is used, then the system is simple to implement, but it lacks the flexibility to adapt to different machine learning models and operations

Engineering Contradiction:
Improvemodel adaptabilityVSAvoidprocessor flexibility
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent designs a universal analog computing platform that can evaluate different types of transfer functions (e.g., ReLU, sigmoid, tanh) by configuring the analog circuit parameters. This multi-functional approach allows the same hardware to adapt to various machine learning models and operations without requiring complex reconfiguration mechanisms, achieving versatility with minimal added complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 system achieves MTF evaluation with a footprint reduction to 85 mm x 65 mm x 60 mm, ensuring image quality within five percent of standard methods at a ninety-five percent confidence level, reducing costs and improving usability.

Implementation Method 1

a relay lens configured to direct light representing the provided pattern from the image source toward the camera such that the desired image appears as a virtual image

Methodology Applied
Scientific EffectLens: Lens

Data Source

PatentEP3230776B1Compact modular transfer function evaluation system
Publication Date: 2021.05.26 TRW AUTOMOTIVE US LLC
  • EP3230776B1 patent drawingFigure 1~5
  • EP3230776B1 patent drawingFigure 2
  • EP3230776B1 patent drawingFigure 3

AI summary

A system for evaluating the modulation transfer function (MTF) of a device under test is provided. The system includes an image projector configured to provide light in a pattern representing a desired image. The system further includes a lens configured to direct the provided light toward the device under test as a collimated beam. An image analysis component calculates the MTF for the device under test from the at least one image taken at the device under test and the known characteristics of the image projector and the lens.