nir-vana innovation network

Traditional bread toasting devices have a timer to regulate the toast browning shade of the toast. It is tricky for the user to determine the shade to be obtained since it is common to find different sliced bread (white, whole wheat, gluten-free, etc.) that require different toasting strengths and toasting times. This results in toasting longer than desired or even in the toast being calcined, generating frustration in the user, wasting electricity and wasting bread.
For these reasons, the need arises to propose a substantial improvement in the electric toaster's original design. The proposed invention, developed by research group from a Spanish university, consists of a device that prompts the user to determine the desired shade of toast in food through a shade selection interface. This device can automatically detect the slice of bread and eject it when the toast reaches the toast shade selected by the user.
The toasting device comprises at least one machine vision perception system, consisting of a color sensor camera with a wide-angle lens, installed on the side of the toasting area to capture the entire toasting surface. This system is isolated from the heat of the toasting area using a glass, capable of creating a thermal break between both sides. Besides, it has a lighting system at the bottom of the toasting area, achieving a uniform illumination of the toast.
Once the slice of bread has been introduced by the user and the desired toasting tone has been defined, a microcontroller activates the lighting system and analyzes an image taken by the camera, detecting the area of the image where the slice of toast is located. The controller activates the thermal heating system consisting of halogens and continuously monitors the detected slice surface color. When the user-defined browning shade is reached, the controller stops the thermal heating system and actuates the ejection mechanism.
Thanks to the device described in the present invention, a very efficient and low-cost sensing system is available, with a much higher resolution of the toast shade than can be provided by photodiode-based systems. Also, by having an artificial vision system, the slice of bread introduced can be of any shape or type since the toast's surface is automatically detected to evaluate the shade during toasting.
The group is looking for appliance design and manufacturing companies for license or manufacturing agreements.

Advantages & innovations

The invention herein proposed consists of the machine vision-based perception system for a bread toasting device adaptive to the type of bread and slice, capable of analyzing the toasting shade in real-time, such that when the toasting shade matches the one selected by the user, it automatically stops the toasting process avoiding calcining the slice, providing the user with a toast with the desired grade. - The perception system can analyze the toastiness of the entire surface of the bread rather than at a single point described in other patents. - The system uses a machine vision-based perception system comprised of a low-cost color sensor camera instead of LDR sensors proposed in other patents. - The system is entirely autonomous; there is no need to reconfigure different roasting times beforehand. - In addition to identifying the inserted slice of bread and its type to adjust the toasting settings to the optimal ones, the system can monitor how the toasting evolves and stop it at the user's desired point. - The user experience is entirely redesigned by introducing a toast color selector instead of time or power numbers.

Stage of development

Available for demonstration

Partner sought

They are looking for appliance design and manufacturing companies for license or manufacturing agreements.