Japan hopes the 2020 Olympics will be a chance to put its tech sector back on the map after years in which the country's reputation as an industry leader has flagged.

Auto giant Toyota has a roster of five robots with different roles to play, from cutesy renditions of the Olympic mascots to a staid transport bot.

Undoubtedly the most appealing are the toddler-sized versions of the Tokyo 2020 Olympic and Paralympic mascots, the futuristic Miraitowa and Someity.

Blue- or pink-checked, with huge eyes and pointy ears, the mascot robots have multiple joints and arms which can be remotely controlled.

And while the pint-sized pair can't move or talk, a camera inside their heads helps them interact with spectators and athletes, said Tomohisa Moiradaira, an official responsible for Tokyo 2020 robot development at Toyota.

"Thanks to the camera, the robots can recognize people's expressions and respond back," he told reporters.

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"If a person moves away it will look sad."

The mascot's "feelings" are reflected in its eyes: they can display hearts or stars depending on emotions.

Toyota has suggested the mascot robots could welcome athletes and spectators, and possibly help engage children with the Games.

Significantly less cute -- but slightly more practical -- is the company's Field Support Robot, a suitcase-sized automaton on wheels that will help Olympic staff.

It is capable of following staff, while avoiding obstacles, and can be loaded with items like javelins or discusses, helping "reduce the amount of time needed to retrieve items as well as reduce the amount of staff labor for events", Toyota said.

Other offerings include robots designed to support people in wheelchairs or deliver food to spectators.

For those who can't attend the Games, there's the T-TR1, effectively a human-sized narrow screen on wheels equipped with a camera.