Abstract: For obtaining an improved characteristic, particularly an improved after-image characteristic of image pickup tubes, a target of the tube is produced by at first forming a striped transparent conductive film on a substrate such that the angle formed between the surface of the substrate and the edges of cross-section of the film falls within a range below 20.degree., and then forming a photoconductive film on the striped transparent conductive film. In order to control the angle formed between the surface of the substrate and the side edges of cross-section of the transparent conductive film, at first a mask of a predetermined pattern is formed on the transparent conductive film with a posi-type photosensitive material, and is subjected to an ultraviolet ray. The mask is then heat treated so that the side edges of the mask may be suitably tapered. Finally, the transparent conductive film is formed by sputter etching.

Abstract: An apparatus for vacuum deposition comprising a turn-table for holding substrates for deposition, and a plurality of evaporation boats arranged in opposition to a circumferential part of the turn-table, the turn-table being rotated at deposition whereby vapors from the respective boats can be cyclically accumulated and stuck onto the substrates, further comprises at least one film-thickness monitor which is fixed to the turn-table and which detects the quantity of a deposited substance of one layer stuck every time the substrates pass over each boat, and means to receive a signal from the film-thickness monitor and divide the signal time sequentially, thereby detecting at least one of the deposition rate and the total amount of the vapor from each boat, and to control the quantity of the vapor arriving to the substrates for deposition from each boat while comparing the detected value with a predetermined value.

Abstract: A photoconductive film comprises a first region containing Se in which Te and an element capable of forming deep levels in Se are added at concentrations lower than 10 atomic % inclusive on average, respectively, a second region disposed on the first region and containing Se in which Te is added with a continuous distribution of concentration having a peak value greater than 15 atomic % inclusive, a third region disposed on the second region and containing Se in which an element capable of forming deep levels in Se is added with a continuous distribution of concentration having a peak value greater than 15 atomic % inclusive, and a fourth region disposed on the third region and containing Se in which Te and an element capable of forming deep levels in Se are added at concentrations lower than 10 atomic % inclusive on average, respectively.

Abstract: In a target structure for use in a photoconductive image pickup tube, a P-type photoconductive film is deposited on an N-type transparent conductive film which is deposited on a transparent substrate. The P-type photosensitive film comprises first and second photoconductive substances. The commencement of the deposition of the first photoconductive substance is delayed a predetermined time from that of the second photoconductive substance thereby forming a film of the first photoconductive substance which is not contiguous to the junction surface between the N-type transparent conductive film and the P-type photoconductive film.

Abstract: An image pickup tube target wherein a rectifying contact which is formed at a boundary of a first layer of a material selected from the group consisting of tin oxide, indium oxide, titanium oxide, cadmium sulfide, zinc sulfide, cadmium selenide, zinc selenide, n-type germanium, n-type silicon and mixture thereof, and a second layer of a material mainly consisting of selenium and including halogen, is reversely biased and operated at a region where signal current is saturated with respect to applied voltage. The second layer of the material includes 50 atomic percent or more of selenium and 0.1 - 1000 atomic ppm of halogen. More preferably, the second layer comprises 3-20 atomic % of arsenic, 0.1-20 atomic ppm of iodine and balance mainly consisting of selenium.