Radiation image inspection apparatus

Abstract

A radiation image inspection apparatus for inspecting articles. The inspection apparatus includes a radiation source which generates and directs radiation, preferably x-rays, toward and around the article. The radiation penetrates and passes around the article and strikes a screen having a coating formed of a rare earth element. The coating exhibits fluorescence when struck by incident radiation and becomes illuminated, generating a first light image of the article. The first light image passes through a plurality of lenses which maintain the intensity of the light image before striking a camera having a front camera screen. The camera by means of an internal sweep beam scans the camera screen and generates an electrical output signal corresponding to the image on the camera screen. A controller controls the operation of the camera and radiation source in either of two modes. In the first mode of operation the radiation source is energized to continually generate radiation and the camera output is blanked for a pre-determined amount of time after the inspection sequence begins to enable radiation energy to build up on the screen thereby maximizing the intensity of the visible light image generated on the screen. At the end of the pre-determined time interval, the camera is activated to generate a signal corresponding to the image on the camera screen. In the second mode of energization, the radiation source and the camera are pulsed for a short time period, with the radiation source being energized at a high intensity level.