JPS55143761A - Focus magnet - Google Patents
Focus magnetInfo
- 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
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.
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)
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 |
-
1979
- 1979-04-24 JP JP5040779A patent/JPS55143761A/en active Pending
Cited By (10)
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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