Projection tube with X-ray shielding means on target

摘要

A projection tube projects in front a visible light image produced by irradiating a target having a fluorescent screen formed on one surface thereof with an electron beam emitted from an electron gun. The projection tube includes an X-ray shield disposed to cover the surface of the target excluding the fluorescent screen, whereby the X-ray generated by irradiating the fluorescent screen on the target with the electron beam are shielded to prevent the transmission of the X-rays to the front of the projection tube, and also the X-ray shield has the effect of dissipating the heat from the target and simplifying the target positioning operation in the manufacture of projection tubes.