The smile scanner aims to improve service to customers
A Japanese rail firm has introduced a system to check that staff are smiling enough at all times.
Computerised scanners around 15 Tokyo stations will measure the smile's curvature to ensure it is broad enough.
Those failing to measure up - literally - will be advised to look less serious and more cheerful.
The system will also be introduced at a hospital in Osaka to check staff friendliness and at a truck stop to measure the tiredness of drivers.
The BBC's Roland Buerk, in Tokyo, says that the Japanese highly value customer service.
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It's nice when someone smiles, but it's more important to give good service
It is standard practice, our correspondent explains, for smartly-dressed train conductors to bow as customers enter and leave train carriages.
The software has been developed by Japanese firm Omron.
They suggests that future applications may include shops - where they could be positioned to measure the reaction of customers to products on display.