The imaging principle of CR (Computer Photograph) is briefly described.

an IP (imaging plate) consisting of a base layer, a phosphor layer and a protective layer is irradiated by X-rays, and the received X-ray photon energy is stored in the crystal in a latent image mode. The IP is placed in the cassette of general X-ray photography, and the exposed imaging plate (IP) is sent to the reader. The IP is automatically taken out and scanned by the laser beam, so that the latent image stored in the IP crystal emits fluorescence, which is received by the photomultiplier tube and converted into an electrical signal. The reader transmits the digital image information to the processor, and the processed image can be stored in an optical disk, a magnetic disk or printed into a CR photo by laser.