Hitachi, Ltd.

Nippon Hoso' Kyokai

Other

Hitachi Electronic Devices Co., Ltd.

Yasuhiko Nonaka

Keiichi Shidara

Naohiro Goto

Kenkichi Tanioka

Eisuke Inoue

Tadaaki Hirai

Yukio Takasaki

Tatsuro Kawamura

Kazutaka Tsuji

Tatsuo Makishima

Takashi Yamashita

Sachio Ishioka

Kazuhisa Taketoshi

Tsuyoshi Uda

Masaaki Aiba

Junichi Yamazaki

Kenji Sameshima

Hirofumi Ogawa

Eikyuu Hiruma

Mitsuo Kosugi

Shiro Suzuki

Masanao Yamamoto

Chushirou Kusano

Eikyu Hiruma

Yochizumi Ikeda

Masakazu Fukushima

Shinichi Kato

Masanori Maruyama

Chihaya Ogusu

Hirokazu Matsubara

Takashi Kono

Fumihiko Ando

Takaaki Unnai

Shirou Suzuki

Takao Kuriyama

Hiroshi Takakura

Michihide Shibata

Yohitsumu Ikeda

Teruo Uchida

Masamichi Moriya

Yoshizumi Ikeda

A cathode ray tube has a cathode structure including a cathode body comprised of porous refractory metal impregnated with electron-emissive material, a metal cup for containing the cathode body therein, a metal sleeve having a closed end and mounting a heater therein, a cylindrical metal eyelet and a plurality of thin metal wires stretched across one end of the metal eyelet and suspending the metal cup and the metal sleeve concentrically with and in the cylindrical metal eyelet. The metal cup and the closed end of the metal sleeve are fixed with the plurality of thin metal wires interposed therebetween, and ends of the plurality of thin metal wires are welded to a metal flange formed at the one end of the metal eyelet. The metal cup can be welded to the closed end of the metal sleeve by an electron beam with the plurality of thin metal wires interposed therebetween. By virtue of providing the metal flange, the contact area for welding the metal wires is increased, thereby improving the welding strength and reliability.

Cathode structure for a cathode ray tube

A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property. In one aspect of the present invention, the amorphous semiconductor layer is amorphous Se. In another aspect of the present invention, the amorphous semiconductor layer is composed mainly of tetrahedral elements including at least an element of hydrogen or halogens. When using the amorphous semiconductor layer composed mainly of tetrahedral elements, the charge multiplication effect is produced mainly in the interior of the amorphous semiconductor, and thus it is possible to obtain a thermally stable photoconductive device having a high sensitivity while keeping a good photoresponse.

Photoconductive imaging apparatus

Disclosed is a photoelectric conversion device which comprises: a photoconductive layer made of amorphous semiconductor material which shows charge multiplication and which converts photo signals into electric signals; and a substrate having electric circuits or the like (for example switching elements) for reading the electric signals. The amorphous semiconductor material used according to the invention shows the charge multiplication action under predetermined intensity of electric field so that a high sensitive photoelectric conversion device having a gain which is not smaller than 1 is realized.

Amorphous photoelectric conversion device with avalanche

A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property.

Photoconductive device and method of operating the same

A target of an image pickup tube, having a transparent substrate, a transparent conductive film, a p-type photoconductive film made mainly from amorphous Se, and an n-type conductive film capable of forming a rectifying contact at the interface with the p-type photoconductive film, using the rectifying contact as a reverse bias, characterized in that the p-type photoconductive film containing at least a region having more than 35%, and to 60% by weight of Te in the film thickness direction, and at least a region containing 0.005 to 5% by weight of at least a material capable of forming shallow levels in the amorphous Se in the film thickness direction, has good after-image characteristics even if operated at a high temperature.

Target of image pickup tube

There is disclosed an image pick-up tube target comprising an N-type conductive film formed on a transparent substrate, and a P-type photoconductive film in rectifying contact with the N-type conductive film and comprising a first layer containing As and Se, the average concentration of As in the first layer being below 8% by weight, a second layer containing As and Se, a third layer containing As and Se, the concentration of As being in the range of 8 to 20% by weight and thickness of the third layer being in the range of 5 to 50% of the total thickness of the P-type photoconductive film, in the order named, and a beam landing layer.

Image pick-up tube target

A camera tube device for use in a television camera comprises an electron gun including a cathode electrode for emission of an electron beam, and first and second grid electrodes respectively having apertures for controlling the diameter of the electron beam. The aperture of the second grid electrode is sufficiently smaller than the aperture of the first grid electrode. The first grid electrode is applied with a positive voltage relative to the cathode electrode and the second grid electrode is applied with a positive voltage relative to the cathode electrode which is higher than that applied to the first grid electrode. The positive voltage applied to the first grid electrode has such a value that forms the electron beam having passed through the aperture of the first grid electrode into a laminar flow beam. As the level of brightness of the object increases, the positive voltage applied to the first grid electrode is decreased to increase the amount of electron beam passing through the aperture of the second grid electrode.

Television camera tube device

A structure of a photoconductive film related to a target of an image pickup tube of the photo conductivity type is disclosed. This photoconductive film is formed from mainly Se and Te is added in a central part thereof. Further, As, which is considered to form a deep trap level which captures electrons in Se and GaF.sub.3, etc. which form negative space charges by capturing electrons in Se are added in the region adjacent to the region where Te exists. In addition, a thickness of film in the region where GaF.sub.3, etc. exists is selected to be thinner (not smaller than 20 .ANG. and not larger than 90 .ANG.) than a value which has been adopted so far.

Doped photoconductive film including selenium and tellurium

An image pickup tube target includes a Se-As-Te photoconductive layer whose arsenic concentration changes in a direction of thickness of the Se-As-Te photoconductive layer, a carrier extraction layer having a high arsenic concentration and being contiguous to the Se-As-Te photoconductive layer, a capacitive layer having a low arsenic concentration and being contiguous to the carrier extraction layer, a doped layer obtained by doping In.sub.2 O.sub.3, MoO.sub.2 or a mixture thereof in an interface between the carrier extraction layer and the capacitive layer.

Image pickup tube target

A photoconductive image pick-up tube target comprises a transparent substrate, an N-type conductive film formed on the transparent substrate, and a P-type photoconductive film in rectifying contact with the N-type conductive film and containing Se, As and Te as sensitizer. The P-type photoconductive film includes a first layer contiguous to the N-type conductive film and containing 94.+-.1% by weight of Se and 6.+-.0.5% by weight of As, a second layer formed on the first layer and containing 64.+-.4% by weight of Se, 3.+-.0.5% by weight of As, and 33.+-.2% by weight of Te, a third layer formed on the second layer and containing Se and As, and a fluoride doped region extending over the first layer and a front half layer of the second layer and having a fluoride concentration of 0.1 to 3.0% by weight. The third layer has an As concentration which has a peak of 28.+-.1% by weight at a site contiguous to a rear half layer of the second layer and reduces gradually.

A photoconductive film comprising a photo-conductive layer which is mainly made of selenium and a region added with tellurium in a direction of the thickness of the layer, wherein at least either one of a portion in a direction of hole flow of said region added with tellurium and a portion in the hole flow of another region which is located adjacent to said region added with tellurium is doped with at least one member selected from the group consisting of an oxide, a fluoride and elements which belong to the group II, III and VII, which are capable of forming a negative space charge in selenium, at a concentration in a range of 10 ppm to 1% by weight on an average. Typical examples of such oxide, fluoride and element include CuO, In.sub.2 O.sub.3, SeO.sub.2, V.sub.2 O.sub.5, MoO.sub.3, WO.sub.3, GaF.sub.2 InF.sub.3, Zn, Ga, In, Cl, I, Br and the like. The after image characteristic ascribable to incident light of high intensity can be significantly improved.

Doped photoconductive film comprising selenium and tellurium

A photoconductive image pick-up tube target comprising an N-type semiconductor film formed on a transparent substrate, and a P-type photoconductive film in rectifying contact with the N-type semiconductor film and containing Se and As and also Te as sensitizers. A layer of said P-type photoconductive film between the N-type semiconductor film and a Te-containing layer of the P-type photoconductive film has an As concentration distribution which is lower on the side of the N-type conductive film and higher on the side of the Te-containing layer.

Photoconductive image pick-up tube target

A photoconductive target having an electrode and a P-type conductive layer mainly made of Se and making rectifying contact at an interface with the electrode, with at least Te being doped in a portion of the P-type conductive layer. At least one metal fluoride forming shallow levels is doped in the region where the signal current is generated for the most part of the P-type conductive layer with an average concentration of not less than 50 ppm and not more than 5% by weight. The metal fluoride is preferably at least one selected from the group consisting of LiF, NaF, MgF.sub.2, CaF.sub.2, BaF.sub.2, AlF.sub.3, CrF.sub.3, MnF.sub.2, CoF.sub.2, PbF.sub.2, CeF.sub.3 and TlF. The high light sticking of the photoconductive target can thus be considerably reduced.

Photoconductive target

The target comprises a transparent substrate, an N-type transparent conductive film formed on the substrate, a P-type photoconductive film formed on the N-type conductive film and a heterojunction formed at the interface between the N- and P-type films. The P-type photoconductive film contains selenium, tellurium and arsenic of which selenium and arsenic are distributed continuously from the heterojunction throughout the thickness of the P-type photoconductive film whereas the distribution of tellurium is spaced from the heterojunction and localized in the vicinity of the heterojunction. The total amount of arsenic contained in the P-type photoconductive film ranges from 2.5 to 6% by weight.

Targets for use in photoconductive image pickup tubes

Growing community of inventors

Mobara, Japan

Yasuhiko Nonaka