An imaging sensor was a piece of sensor technology used to take photographs or images of something.
According to Sub-Commander T'Pol, Vulcan hand scanners were equipped with imaging sensors. In June 2151, she was asked by Captain Jonathan Archer to use these imaging sensors to take images of the secret Vulcan listening post they discovered beneath the monastery at P'Jem and hand it to the Andorians. (ENT: "The Andorian Incident")