Superorthicon-type television camera tube having target and fine-mesh metal grid coated with semiconductor material of relatively low inelastic electron reflection factor

A superorthicon-type television camera tube comprising a photoelectric cathode, a target spaced opposite the cathode, said target including a film, said film being subject to secondary emission upon exposure to a photoelectric image and storing a resulting charge, a fine-mesh metal grid between said film and said cathode, a coating on both said grid and film of the target and of a semiconductor material having an inelastic electron reflection factor lower than that of the material of said film, semiconductor material being selected from the group comprising oxides of magnesium, aluminum, lithium and compounds of said oxides, said grid having a side facing the cathode and a side facing the target, said coating being on the side of the grid facing said cathode, an electron gun for scanning said target, and an evacuated envelope in which said cathode, target and gun are located.