[Development of the computed electroradiography. Trial manufacture of digital imaging system]

The fundamental element of a latent image on a selenium plate of Electroradiography is a electrical charge. Therefore, the spatial resolution which can be expected from Electroradiography is extremely high. Here, the author developed the Pulse Electron Beam Scanner (PEBS) as the technique to obtain digital pictorial information from the latent image and obtained following results; 1. We succeeded in converting the latent image into digital signal with high accuracy by using secondary emitted electron through the apparatus that features pulsed electron beam, summing function for secondary emitted electron and plurally arranged detectors and extraction field applied grid. 2. The spatial resolution which we can enjoy to obtain through this apparatus is greater than 500 Lp/mm and the dynamic range at the time when we obtained 500 Lp/mm in terms of the voltage applied to the electrode was +60V to +110V. 3. We succeed in obtaining the digital X ray picture of the bone trabecular structure of human spongy bone with 50 power magnification without using any enlargement picture taking method. The above results indicate that converting the latent image on the selenium plate into digital signal with very high spatial resolution by using PEBS system was achieved. Therefore, we can conclude that we succeeded in obtaining the high spatial resolution digital image from the electroradiographic latent image which has the spatial resolution as high as electrical charge distribution.