A pervert who posed online as a teenage boy to persuade underage girls to send pictures of themselves was collared when he took his phone to a shop for repair.
Jeffrey Roe, 33, claimed to be a 17-year-old boy on social networking sites to persuade girls to send explicit pictures of themselves.
Newcastle Crown Court heard the pervert built up a sickening collection of 55 "folders", each containing images of named young women and had a haul of hundreds of random images of children being abused.
Detectives managed to trace five youngsters Roe had been communicating with.
One girl had been convinced to send him a total of 102 pictures of herself, believing she was sending them to a teenage boy.
Roe was collared when he took his mobile phone to the O2 shop in King Street, South Shields, using a false name, because it developed a fault and a shocked worker realised what it contained so alerted the police.
A total of 1,695 images and movies, some of the most serious of their type were found on two phones belonging to Roe, who admitted himself his collection was "terrifying".
Roe, of Oak Crescent, Whitburn, admitted possessing indecent images of children and encouraging the commission of an offence.
Judge Tim Gittins sentenced him to 16 months behind bars and said he must comply with the terms of a sexual harm prevention order and sign the sex offenders register for ten years.
The judge told him: "You sought assistance for your mobile phone that was not workng properly. The shop assistant who was dealing with you observed, when he checked the phone, there was indecent images, which undoubtedly alarmed and shocked him.
"He took entirely the proper step.
"Examination of your phones revealed not just a large quantity of images of various categories, from the most serious category A images of penetrative sex with young children, to category C involving sexual posing but importantly it revealed contact you had had with a number of girls where you used an identity over social media, purporting to be a 17-year-old youth to persuade them, successfully on a number of occasions, to send indecent images."
Roe asked "I'm actually going to jail?" and said "I'm sorry" as he was led away to start his jail term.
Graeme Cook, defending, said Roe is a carer of his mother, who feels real remorse for what he did.
Mr Cook said: "If his liberty was removed it would cause catastrophic problems for his mother."