Daniel Gareth Dobb, 28, of Willow Holt, Retford, used a seven-inch knife to carry out a robbery at a shop on Carlton Road.
After pleading guilty Dobb was convicted of robbery, three counts of shop theft and possession of a knife.
At Nottingham Crown Court on Tuesday 21st October 2014 he was sentenced to four years and ten months in prison.
The court heard that Dobb and another man had entered the shop at about 8.50am on 1st July 2014.
They threatened the shopkeeper and demanded takings from the till before making off with about £400.
Through their investigations officers linked Dobb to the scene using CCTV analysis and he was arrested.
It was also revealed that he was involved in thefts totalling about £120 at Sainsbury’s Prospect Precinct, on 29th June 2014, and at One Stop, Long Lane, Carlton-In-Lindrick, and Co-op, Doncaster Road, on 2nd July 2014.
Detective Constable Colette Melrose said: “This was a terrifying ordeal for the shopkeeper who feared for her life and has subsequently resigned from the business due to the effect this incident had on her. No one deserves to be faced with such circumstances as they go about their daily business.”
“Armed robberies are thankfully a rare occurrence in Worksop and the sentence reflects the seriousness of the offence.”
A man who was also charged with robbery on 4th July 2014 was released with no further action ahead of the trial.