Microwave oven that recognizes position of food item within cavity for cooking and method of operating the same
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Microwave ovens with automatic heating functions face inaccuracies in determining food item position relative to the infrared sensor when the food and cavity temperatures are similar, leading to suboptimal heating operations and user dissatisfaction.
Innovation Solution
The microwave oven employs an array of infrared sensor pixels and a controller to estimate food item position by recognizing temperature changes caused by the user's hand placing the food, allowing for accurate placement verification before heating, and optionally repositioning the food for optimal sensing and heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the microwave oven waits for temperature contrast between food and cavity to determine food position, then the infrared sensor can accurately detect food position, but the heating operation is delayed and user satisfaction decreases
Solution Approach 1:
The system performs preliminary detection of the user's hand position and movement trajectory before the food is actually placed in the cavity. By detecting the hand's temperature and movement pattern in advance, the system can predict where the food will be placed, eliminating the need to wait for temperature contrast after placement. This preliminary action resolves the contradiction by obtaining position information before the heating operation begins.
Solution Approach 2:
The user's hand serves as an intermediary object that carries temperature information from outside the cavity. By detecting the hand's temperature and trajectory, the system indirectly determines the food's placement position without requiring the food itself to create temperature contrast with the cavity. This intermediary approach allows position detection to occur before the food is heated.
2Adaptability or versatility
If the food item is placed far from the infrared sensor, then the cavity can accommodate the food item, but the temperature determination accuracy decreases
Solution Approach 1:
The system performs preliminary detection of the user's hand position and movement trajectory before the food is actually placed in the cavity. By detecting the hand's temperature and movement pattern in advance, the system can predict where the food will be placed, eliminating the need to wait for temperature contrast after placement. This preliminary action resolves the contradiction by obtaining position information before the heating operation begins.
Solution Approach 2:
The user's hand serves as an intermediary object that carries temperature information from outside the cavity. By detecting the hand's temperature and trajectory, the system indirectly determines the food's placement position without requiring the food itself to create temperature contrast with the cavity. This intermediary approach allows position detection to occur before the food is heated.
3Measurement precision
If the microwave oven heats the food item first to create temperature contrast, then the infrared sensor can detect food position, but the heating time is wasted and user experience deteriorates
Solution Approach 1:
The system performs preliminary detection of the user's hand position and movement trajectory before the food is actually placed in the cavity. By detecting the hand's temperature and movement pattern in advance, the system can predict where the food will be placed, eliminating the need to wait for temperature contrast after placement. This preliminary action resolves the contradiction by obtaining position information before the heating operation begins.
Solution Approach 2:
The user's hand serves as an intermediary object that carries temperature information from outside the cavity. By detecting the hand's temperature and trajectory, the system indirectly determines the food's placement position without requiring the food itself to create temperature contrast with the cavity. This intermediary approach allows position detection to occur before the food is heated.
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
This method ensures accurate temperature determination and improves user satisfaction by allowing for precise food placement verification and automatic repositioning, enhancing the efficiency and effectiveness of the automatic heating process.
Implementation Method 1
an infrared sensor comprising an array of pixels, each pixel configured to generate an output and each pixel corresponding to a different position of the array of positions of the cavity
Implementation Method 2
recognize a rise and fall in the temperature at one or more positions of the array of positions within the cavity
Implementation Method 3
a magnetron within the microwave oven can emit microwaves into the cavity. Water molecules of the food item within the microwave oven absorb the microwaves, which causes the water molecules to vibrate and generate heat
Data Source
AI summary
A microwave oven includes a controller in communication with an infrared sensor and a human-machine interface, the controller configured: (i) to determine a temperature at each position of a cavity as a function of the output of each pixel of the infrared sensor; (ii) to recognize a rise and fall in the temperature at one or more positions within the cavity; (iii) to estimate the position or positions within the cavity that a food item occupies as a function of the one or more positions within the cavity where the controller recognized the rise and fall in temperature occurred; and (iv) to determine whether the position or positions that the food item is estimated to occupy is adequate for the controller to determine accurately a temperature of the food item during an automatic heating operation that utilizes the infrared sensor.