JPS55143761A - Focus magnet - Google Patents

Focus magnet

Info

Publication number
JPS55143761A
JPS55143761A JP5040779A JP5040779A JPS55143761A JP S55143761 A JPS55143761 A JP S55143761A JP 5040779 A JP5040779 A JP 5040779A JP 5040779 A JP5040779 A JP 5040779A JP S55143761 A JPS55143761 A JP S55143761A
Authority
JP
Japan
Prior art keywords
pair
permanent magnets
focus
axial direction
magnetic poles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP5040779A
Other languages
Japanese (ja)
Inventor
Teruo Umehara
Norio Matsumoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Proterial Ltd
Original Assignee
Hitachi Metals Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Metals Ltd filed Critical Hitachi Metals Ltd
Priority to JP5040779A priority Critical patent/JPS55143761A/en
Publication of JPS55143761A publication Critical patent/JPS55143761A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/58—Arrangements for focusing or reflecting ray or beam
    • H01J29/64—Magnetic lenses

Landscapes

  • Microwave Tubes (AREA)

Abstract

PURPOSE:To facilitate the just focus adjusting of an electron beam by holding a pair of permanent ring magnets having two opposite magnetic poles in axial direction between a pair of yoke plates. CONSTITUTION:Yoke plates 1a-1c having the neck hole 11 of Braun tube at the center are faced each other, where a pair of permanent magnets 2a, 2b having N and S poles in axial direction are held between them such that adjascent magnetic poles have same polarity. Then coils 3a, 3b are located at the inner circumference of the permanent magnets 2a, 2b. When rotating the focus magnet and varying the relative position against an electron gun to adjust the strength of central field, the rotation of the electron gun can be prevented by the repulsion of the permanent magnets 2a, 2b resulting in the facilitation of the just focus adjustment.
JP5040779A 1979-04-24 1979-04-24 Focus magnet Pending JPS55143761A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5040779A JPS55143761A (en) 1979-04-24 1979-04-24 Focus magnet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5040779A JPS55143761A (en) 1979-04-24 1979-04-24 Focus magnet

Publications (1)

Publication Number Publication Date
JPS55143761A true JPS55143761A (en) 1980-11-10

Family

ID=12858004

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5040779A Pending JPS55143761A (en) 1979-04-24 1979-04-24 Focus magnet

Country Status (1)

Country Link
JP (1) JPS55143761A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61211940A (en) * 1985-03-15 1986-09-20 Sony Corp Permanent magnet for electron lens
JPS62290048A (en) * 1986-05-01 1987-12-16 Hitachi Metals Ltd Forcus magnet
EP0251381A2 (en) * 1986-06-25 1988-01-07 Philips Electronics Uk Limited Magnetic lens system
JPH01227336A (en) * 1988-03-04 1989-09-11 Hitachi Metals Ltd Focus magnet
JPH0519180U (en) * 1991-08-21 1993-03-09 吉村化成株式会社 Container
US5227752A (en) * 1990-12-31 1993-07-13 Samsung Electron Devices Co., Ltd. Focus magnet for a projection type cathode-ray tube
EP2302664A1 (en) * 2008-06-24 2011-03-30 Advantest Corporation Multicolumn electron beam exposure apparatus and magnetic field generating apparatus

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61211940A (en) * 1985-03-15 1986-09-20 Sony Corp Permanent magnet for electron lens
JPS62290048A (en) * 1986-05-01 1987-12-16 Hitachi Metals Ltd Forcus magnet
EP0251381A2 (en) * 1986-06-25 1988-01-07 Philips Electronics Uk Limited Magnetic lens system
EP0251381A3 (en) * 1986-06-25 1989-02-08 Philips Electronics Uk Limited Magnetic lens system
JPH01227336A (en) * 1988-03-04 1989-09-11 Hitachi Metals Ltd Focus magnet
US5227752A (en) * 1990-12-31 1993-07-13 Samsung Electron Devices Co., Ltd. Focus magnet for a projection type cathode-ray tube
JPH0519180U (en) * 1991-08-21 1993-03-09 吉村化成株式会社 Container
EP2302664A1 (en) * 2008-06-24 2011-03-30 Advantest Corporation Multicolumn electron beam exposure apparatus and magnetic field generating apparatus
EP2302664A4 (en) * 2008-06-24 2011-09-28 Advantest Corp Multicolumn electron beam exposure apparatus and magnetic field generating apparatus
US8390201B2 (en) 2008-06-24 2013-03-05 Advantest Corp. Multi-column electron beam exposure apparatus and magnetic field generation device

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