Food Cavity 3D Imaging with Single-Camera Focus Variation

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Solution Overview

Problem

Existing food preparation entities face challenges in efficiently determining the three-dimensional shape of food within their cavities with limited technical effort, often requiring multiple cameras, light sources, or distance sensors.

Innovation Solution

A method using a single camera to capture images with different focus points, integrated into the door handle or door structure, which processes these images to establish three-dimensional information of the food, allowing for reduced technical complexity and improved recognition of the food's shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple cameras, light sources, or distance sensors are used to determine three-dimensional shape of food, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvethree-dimensional information accuracyVSAvoidnumber of cameras and sensors
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from capturing 2D images to extracting 3D information by utilizing the focus point dimension. By capturing multiple images with different focus points (depth of field variation) and processing them through defocus amount calculation, the system derives three-dimensional shape data from two-dimensional image planes, effectively using focus as an additional dimensional cue for depth perception.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent replaces mechanical/optical 3D sensing systems (multiple cameras, laser scanners, structured light projectors) with a computational approach using a single camera. Instead of using multiple physical sensors to directly capture 3D data, the system substitutes these mechanical systems with image processing algorithms that calculate defocus amounts and reconstruct 3D shape information from 2D images with varying focus.

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

2Device complexity

If a single camera is used to capture images, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:
Improvecamera system simplicityVSAvoidthree-dimensional information accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary action by capturing multiple images with different focus points before processing. The system systematically varies the focus point across multiple image captures, ensuring that sufficient depth information is collected in advance. This preliminary multi-focus image acquisition enables accurate 3D reconstruction during the subsequent processing stage, compensating for the limitations of using only a single camera.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the focus point parameter of the camera to extract depth information. By systematically varying the focal distance and capturing images at different focus settings, the system transforms a single-camera system into one that can perceive depth. The image processing unit analyzes changes in defocus amount across these parameter-varied images to reconstruct three-dimensional shape, effectively using parameter variation as a depth sensing mechanism.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple images with different focus points are captured and processed, then three-dimensional information accuracy is improved, but loss of time increases

Engineering Contradiction:
Improve3D shape recognition accuracyVSAvoidimage capture and processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent employs periodic action by capturing images at discrete, periodic intervals of focus point variation. Instead of continuous focus sweeping, the system captures images at specific focus settings (e.g., near focus, middle focus, far focus) in a periodic sequence. This periodic sampling of focus states provides sufficient information for 3D reconstruction while minimizing the total time required, balancing measurement precision with time efficiency.

Inventive Principle:
Principle #19Periodic action

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 the determination of three-dimensional information with reduced technical effort, allowing for accurate monitoring of volume changes and cooking status, as well as categorization of food types and adjustment of cooking parameters.

Implementation Method 1

capturing at least two images of said food received within the cavity using a camera, said images comprising different focus points

Methodology Applied
Scientific EffectOptical focusing: Focusing

Data Source

PatentEP3346190B1Food preparation entity
Publication Date: 2020.05.06 ELECTROLUX APPLIANCES
  • EP3346190B1 patent drawingFigure 1~2
  • EP3346190B1 patent drawingFigure 3~4
  • EP3346190B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for calculating three-dimensional information of food received within a cavity (2) of a food preparation entity (1), the method comprising the steps of: - capturing at least one image of said food (3) received within the cavity (2) by a plenoptic camera, said image comprising information regarding the light intensity and the direction of light rays traveling in space; or - capturing at least two images of said food received within the cavity (2), said images being taken from different positions during movement of a camera (4); or - capturing at least two images of said food received within the cavity (2) using a camera (2), said images comprising different focus points; and - processing the at least one image in order to establish three-dimensional information of said food (3) received within the cavity (2).