公开(公告)号：JPH11238477A

公开(公告)日：1999-08-31

申请号：JP4084398

申请日：1998-02-23

Applicant: SONY CORP

Inventor： HARA MICHIO ,  SAKATA MIYOSHI

IPC: H01J29/04 ,  H01J29/48 ,  H01J29/50

Abstract: PROBLEM TO BE SOLVED: To provide an electron gun which is free of a temperature rise too much in the first grid or second grid even if an impregnated cathode is used and can prevent the stray emission intensity from becoming excessive. SOLUTION: An electron gun is structured so that an inner sleeve 10 incorporating a heater H to whose one end an impregnated cathode K is attached fast, is inserted into an outer sleeve 20 and fixed and using a holder 30, and the outer sleeve 20 is installed by means of a holder on a ceramic disc 40 furnished with a first grid G1 and second grid G2, wherein the thermal conductive resistance of a thermal conduction path leading from the heater to the grids G1 and G2 is increased by structuring the inner sleeve 10 so that its length is at most 8 mm, inside diameter at most 1.3 mm, wall thickness at most 40 μm, structuring the outer sleeve 20 so that its wall thickness is at most 40 μm, and the holder s that its wall thickness is at most 80 μm, and thereby the temperature of the grids G1 and G2 in operation is made at most 300 deg.C.

公开(公告)号：JPH11144614A

公开(公告)日：1999-05-28

申请号：JP31200997

申请日：1997-11-13

Applicant: SONY CORP

Inventor： KODAMA TAKESHI ,  HARA MICHIO

IPC: H01J1/28 ,  H01J9/04

Abstract: PROBLEM TO BE SOLVED: To provide a manufacturing method which can improve mass productivity of an impregnated cathode for an electron tube. SOLUTION: A porous tungsten disk 10 composed of a porous metal substrate is impregnated with an electron emitting material 11 (e.g. Ba) at 1650 deg.C for instance, and washed in a washing process 30. Subsequently, an Ir film is formed on the surface of the porous tungsten disk 10. After that, the obtained cathode is subjected to a vacuum heat treatment, for instance, for 5 minutes at 1650 deg.C in a vacuum heat treatment process 40, so that the cathode is activated. Subsequently, a cap 50 and a sleeve 60 are brazed to obtain a completed inner sleeve 80.

公开(公告)号：JPH11120909A

公开(公告)日：1999-04-30

申请号：JP27884497

申请日：1997-10-13

Applicant: SONY CORP

Inventor： HARA MICHIO

IPC: H01J9/04

Abstract: PROBLEM TO BE SOLVED: To avoid the occurrence of a straight emission by performing a heating treatment for mainly removing carbon which is the impurity of an electron emitting material to the electron emitting material prior to a heating treatment for fusing the electron emitting material to impregnate a cathode base with the electron emitting material. SOLUTION: As the electron emitting material, for example, BaCO3 , CaCO3 , and Al2 O3 are blended in a molar ratio of 4:1:1, mixed by wet method by use of a ball mill, and then dried. A binder, for example, paraffin is mixed thereto to manufacture a granular powder having a grain size of about 100 p m. This is pressed into a disc having a diameter of 1.2 mm and a thickness of 0.5 mm to manufacture a compact of electron emitting material. This is thermally treated in vacuum or in an atmosphere of an inert gas such as N2 or hydrogen within the range of 600 deg.C±200 deg.C, preferably at 600 deg.C for 1-30 minutes. The resulting compact 1 is superposed on a cathode base 2, and a fusing heating treatment for impregnation is performed.

公开(公告)号：JPH0528905A

公开(公告)日：1993-02-05

申请号：JP18241691

申请日：1991-07-23

Applicant: SONY CORP

Inventor： HARA MICHIO

IPC: H01J1/28 ,  H01J1/14 ,  H01J29/04

Abstract: PURPOSE:To provide an impregnated type cathode whose electron emission characteristic at low electric fields is remarkably improved and which is capable of practical use at a cathode operating temperature of about 800 deg.CB (luminance temperature). CONSTITUTION:A high melting-point metallic thin layer 2 and a thin layer 3 composed mainly of Sc23 are provided in sequence on the surface of an impregnated type cathode pellet comprising a heat-resistant porous metal base 4 impregnated with an electron-emitting material 5. Thereby the electron emission characteristic of the cathode is such that space-charge limited current is obtained from the operation of the cathode at low temperatures.

公开(公告)号：JPH0436925A

公开(公告)日：1992-02-06

申请号：JP14253190

申请日：1990-05-31

Applicant: SONY CORP

Inventor： HARA MICHIO ,  OGAWA SHINJI ,  TAKEUCHI KATSUSUE ,  KANNA KENICHI

IPC: H01J9/44 ,  H01J9/04

Abstract: PURPOSE:To enhance the electron emitting ability by incorporating such processes in manufacture of an oxide cathode containing In or In compound that decomposition of coprecipitation carbonates is activated after heating of the oxide layer of the cathode under specific heating conditions, and thereby avoiding melting at the time of decomposition activation of the oxide layer. CONSTITUTION:In manufacturing an oxide cathode containing In or In compound, decomposition of coprecipitation carbonates is activated 15 after heating 14 of the oxide layer of the cathode at 500-800 deg.C for three min or more. The processes are such that an electron gun having cathode coated with coprecipitation carbonate is encapsulated in a tubing, and the cathode decomposition activating process 15 is conducted in the condition where the inside of this tubing is put under high degree of vacuum ranging 10 thru 10 Torr.

公开(公告)号：JPH08138535A

公开(公告)日：1996-05-31

申请号：JP27772694

申请日：1994-11-11

Applicant: SONY CORP

Inventor： KODAMA TAKESHI ,  NAKAHIRA TADAKATSU ,  HARA MICHIO

IPC: H01J9/04

Abstract: PURPOSE: To provide a manufacturing method of an impregnated cathode which effectively suppresses a variation of a cut-off voltage with the elapse of time and grid emission and further excels in mass productivity. CONSTITUTION: In a process after impregnating a base metal with an electron emitting substance and further before incorporating it into a cathode-ray tube, excessive Ba in the electron emitting substance contained in the base metal is eliminated. An excessive substance eliminating process is conducted within a range of 1600-2000 deg.C and heating time 0.1-60 minutes, particularly the about 1800 deg.C and heating time of about 10 minutes being desirable. The heating is desirable to be conducted in a vacuum or non-oxidizing atmosphere. The excessive substance eliminating process is desirable to be conducted in a process before the base metal is fixed to a cap.

公开(公告)号：JPH0794074A

公开(公告)日：1995-04-07

申请号：JP25644993

申请日：1993-09-20

Applicant: SONY CORP

Inventor： HARA MICHIO ,  NAKAHIRA TADAKATSU ,  KODAMA TAKESHI

IPC: H01J1/28 ,  H01J1/14 ,  H01J9/04

Abstract: PURPOSE:To provide an impregnated cathode and an impregnated cathode assembly which require no complicated work of confirming the surface and reverse surface of the impregnated cathode when the impregnated cathode is house in a cup, and a method for manufacturing the impregnated cathode in which a sufficient connecting strength can be provided between a porous base body and a supporting cup without using a brazing material. CONSTITUTION:An impregnated cathode 1 is formed of a porous base body 12 consisting of a high melting point metal and an electron emitting material impregnated in the porous base body, and platinum metal layers 14 are formed on the surface and reverse surface of the porous base body 12. An impregnated type cathode assembly is formed of a cup consisting of a high melting point metal, and the impregnated type cathode 10 housed in the cup, and the inner surface of the cup 20 is fused to the platinum metal layer 14 formed on one surface of the porous base body 12. A method for manufacturing the impregnated type cathode assembly comprises fixing the porous base body into the inner surface of the cup, and then impregnating the porous base body with the electron emitting material.

公开(公告)号：JPH0668788A

公开(公告)日：1994-03-11

申请号：JP22396292

申请日：1992-08-24

Applicant: SONY CORP

Inventor： NOGAMI YASUHIRO ,  HARA MICHIO

IPC: H01J9/04

Abstract: PURPOSE:To provide a manufacturing method of an impregnation type cathode structure body by which rated electric power can be reduced when it is operated and dispersion of a temperature can be restrained and reliability can be improved without degrading a body structure member such as a cup. CONSTITUTION:In a manufacturing method of an impregnation type cathode body structure having a cathode base body 1 composed of a porous metallic body impregnated with an electron emitting material, a high melting point metallic cup 2 to which the cathode base body is fixed and a high melting point metallic sleeve 4 where the cup 2 is embedded in/welded to the top part, fixation of the cathode base body 1 and the high melting point metallic cup 2 is carried out by means of brazing while being heated in a vacuum by interposing a brazing material 3 between the cathode base body 1 and the cup 2.

公开(公告)号：JPH04253138A

公开(公告)日：1992-09-08

申请号：JP2800691

申请日：1991-01-29

Applicant: SONY CORP

Inventor： HARA MICHIO ,  SHIROMIZU SHINICHIRO ,  OGAWA SHINJI

IPC: H01J1/28 ,  H01J1/14

Abstract: PURPOSE:To provide a stable low-temperature operation by forming a scandium oxide layer with the thickness 1-50nm on the electron emitting face of an impregnated cathode. CONSTITUTION:An electron emitting material 3 is impregnated into a heat- resistant porous substrate 2. A scandium oxide layer 4 with the thickness 1-50nm is formed on the surface. The substrate 2 is a disk-shaped substrate sintered with tungsten grains. The substrate 2 preferably has the relative density 70-80% (porosity 15-30%). An electron emitting material containing Ba is used as the electron emitting material 3 to be impregnated into the substrate 1, and a composite oxide made of BaO, CaO, Al2O3 is normally used.

公开(公告)号：JPH0393126A

公开(公告)日：1991-04-18

申请号：JP22843389

申请日：1989-09-05

Applicant: SONY CORP

Inventor： HARA MICHIO

IPC: H01J1/14 ,  H01J1/142 ,  H01J1/20 ,  H01J9/04

Abstract: PURPOSE:To improve electron emitting function by using alkaline earth metal carbonates which contain at least one of zinc(Zn) and aluminum(Al) in their crystal structure as alkaline earth metal carbonates. CONSTITUTION:In an oxide-coated type cathode, alkaline earth metal carbonates containing at least one of Zn and Al in their crystal structure are used as alkaline earth metal carbonates. Addition of Zn and Al to the cathode has an effect to improve electron emitting function in the same as addition of In and further during the preparation of the cathode, characteristic of Zn and Al as elements forming amphoteric compounds are made effective so that supposed-to-be harmful elements or their compounds contained in the alkaline earth metal carbonate are sufficiently removed. In this way, the property of the cathode is stabilized easily and the improvement of the electron emitting function of the cathode results in decreasing the working temperature of the cathode and also extending its service life.