From the Kodak website here How they work
It all starts with our exclusive sensor design, the foundation of our unique system. Our intraoral and extraoral sensors consistently provide a high-quality, film-resolution image, free from distortion and noise. The sensor records the image and transforms it into an electrical signal that is converted to binary information and displayed on your PC.
The Optical Fiber
The optical fiber receives light from the scintillator then transfers the light into the sensor and blocks x-ray photons not converted to light by the scintillator so that it does not damage the sensor or create electronic noise on the image.
The Scintillator Screen
This highly sensitive screen receives the x-ray photons and converts them to light through fluorescence, which is received first by the optical fiber and then by the sensor to create the image.
The resulting electronic signal is converted to a digital file and the resulting image is displayed on the computer monitor.