Alan Wilfred Redfern, 68, appeared to be driving at speed on the A64 in Sherburn when he was seen by a North Yorkshire Police safety camera van.
But when the van tried to get a reading of the exact speed of the silver Volvo estate, it was blocked from doing so.
A closer inspection of images captured by the van on August 31 showed that there was a small transponder device under the Volvo’s number plate.
When officers from the force's Traffic Bureau visited Redfern’s home in Cotswold Avenue, they found the device and seized the car.
Redfern’s car was dismantled and officers located the jammer system.
Extensive testing revealed that when a police safety camera was aimed at the Volvo, an alarm noise sounded and a red light lit up on the dashboard.
The jammer not only warned Redfern that a camera was attempting to read his speed, but also blocked the signal for long enough to allow him to slow down and avoid detection.
Redfern was found guilty at trial of perverting the course of justice by having a laser jammer device fitted to his car.
He received a four month prison sentence, suspended for two years, when he appeared at York Crown Court yesterday.
The court also banned him from driving for six months and ordered him to pay Â£2,615 in costs and fines.
Speaking about the case, investigating officer Traffic Constable Andy Forth said: “To believe you are above the law and do not have to abide by the speed limit, like Redfern clearly did, is unacceptable.
"His deliberate action to pervert the course of justice, by fitting this type of device to his vehicle, clearly shows his disregard for the law and the safety of other road users."
He said North Yorkshire Police camera operators were trained to detect the use of those type of devices and the speed of the vehicle could still be calculated.
“If evidence suggests that a person’s vehicle is fitted with any type of device which may interfere with speed enforcement equipment, North Yorkshire Police will fully investigate the matter and seek to bring any offenders before the courts,” he said.