JPH0138350B2 - - Google Patents
Info
- Publication number
- JPH0138350B2 JPH0138350B2 JP54065775A JP6577579A JPH0138350B2 JP H0138350 B2 JPH0138350 B2 JP H0138350B2 JP 54065775 A JP54065775 A JP 54065775A JP 6577579 A JP6577579 A JP 6577579A JP H0138350 B2 JPH0138350 B2 JP H0138350B2
- Authority
- JP
- Japan
- Prior art keywords
- permanent magnet
- magnetic field
- ring
- shaped permanent
- magnet
- 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.)
- Expired
Links
- 230000002093 peripheral effect Effects 0.000 claims description 6
- 229910000831 Steel Inorganic materials 0.000 claims description 5
- 239000010959 steel Substances 0.000 claims description 5
- 238000010894 electron beam technology Methods 0.000 description 11
- 230000005684 electric field Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 229910000828 alnico Inorganic materials 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000005686 electrostatic field Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
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
- H01J29/68—Magnetic lenses using permanent magnets only
Description
【発明の詳細な説明】
本発明は、例えばテレビ用ブラウン管におい
て、電子ビームを集束する磁界を発生させるため
のフオーカスマグネツトに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a focus magnet for generating a magnetic field for focusing an electron beam, for example in a television cathode ray tube.
一般に、テレビ用ブラウン管の電子ビーム集束
装置としては、電子ビームを静電界により形成さ
れる電界レンズにより集束させる電界レンズ方式
のものが用いられている。他方、特殊管用とし
て、例えばＸ線管、マグネトロン、進行波管等に
は、電子ビームを磁界型電子レンズにより集束さ
せる磁界レンズ方式のものが用いられている。そ
して最近では、一般のテレビ用ブラウン管装置に
おいても、電界レンズ方式に比較し解像度がすぐ
れている磁界レンズ方式の適用が検討され、特に
ビデオプロジエクター等の用途にはすでに商品化
されている。 Generally, as an electron beam focusing device for a television cathode ray tube, an electric field lens system is used in which the electron beam is focused by an electric field lens formed by an electrostatic field. On the other hand, for special tubes such as X-ray tubes, magnetrons, traveling wave tubes, etc., a magnetic field lens system is used in which an electron beam is focused by a magnetic field type electron lens. Recently, the application of the magnetic field lens system, which has superior resolution compared to the electric field lens system, has been considered in general television cathode ray tube devices, and it has already been commercialized especially for applications such as video projectors.
磁界レンズ方式のフオーカスマグネツトとして
は、電子ビーム集束手段としてコイルを用いたも
のもあるが、装置の小型化及び軽量化の点では永
久磁石を用いたものが有利である。 Although some magnetic field lens type focus magnets use coils as electron beam focusing means, those using permanent magnets are advantageous in terms of making the device smaller and lighter.
しかしながら、永久磁石を用いた磁界レンズ方
式のフオーカスマグネツトは、ブラウン管のネツ
ク部に取り付けられるために重量が大であるとネ
ツク部を破損するおそれがあり、小型、軽量化が
特に必要とされている。しかして永久磁石により
生ずる中心磁界の強度が低いと、電子ビームの集
束効果が弱まり、解像度が低下してしまう。 However, since the focus magnet, which uses a magnetic field lens and uses a permanent magnet, is attached to the neck of a cathode ray tube, if it is heavy, there is a risk of damaging the neck, so there is a particular need to make it smaller and lighter. There is. However, if the strength of the central magnetic field generated by the permanent magnet is low, the focusing effect of the electron beam will be weakened and the resolution will be reduced.
しかるに従来のフオーカスマグネツトでは、磁
気回路について十分な検討がなされておらず、小
型、軽量で、しかも効率よく高い中心磁界が得ら
れるような構造とはなつていなかつた。 However, in conventional focus magnets, the magnetic circuit has not been sufficiently studied, and the structure has not been designed to be small, lightweight, and efficiently obtain a high central magnetic field.
したがつて本発明の目的は、小型かつ軽量であ
つてしかも中心磁界を効率よく得ることのできる
フオーカスマグネツトを提供することである。 SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a focus magnet that is small and lightweight and that can efficiently obtain a central magnetic field.
以下本発明を図面により説明する。 The present invention will be explained below with reference to the drawings.
第１図は本発明の一実施例に係るフオーカスマ
グネツトの縦断面図である。 FIG. 1 is a longitudinal sectional view of a focus magnet according to an embodiment of the present invention.
３は、電子ビームの進行方向である軸方向に着
磁されたリング状永久磁石である。１および２
は、中央にブラウン管のネツク５の通過孔を有す
る円板状のヨークプレートであり、リング状永久
磁石３の両端面に、リング状永久磁石３の中心軸
と同一軸上に固着されている。ヨークプレート１
および２はそれぞれ、リング状永久磁石３の内周
面と接する環状のつば部１ａおよび２ａを有す
る。４はリング状永久磁石３の外周面上に固着さ
れた製磁鋼である。本発明においては、永久磁
石、ヨークプレートおよび製磁鋼により磁気回路
部を構成するので、フオーカスマグネツトの軽量
化、小型化をはかることができる。 3 is a ring-shaped permanent magnet magnetized in the axial direction, which is the traveling direction of the electron beam. 1 and 2
is a disk-shaped yoke plate having a passage hole for the cathode ray tube neck 5 in the center, and is fixed to both end faces of the ring-shaped permanent magnet 3 coaxially with the central axis of the ring-shaped permanent magnet 3. Yoke plate 1
and 2 have annular collar portions 1a and 2a that are in contact with the inner circumferential surface of the ring-shaped permanent magnet 3, respectively. Reference numeral 4 denotes magnetic steel fixed on the outer peripheral surface of the ring-shaped permanent magnet 3. In the present invention, since the magnetic circuit section is composed of a permanent magnet, a yoke plate, and magnetic steel, it is possible to reduce the weight and size of the focus magnet.
上記の永久磁石としては、周囲温度の変化に対
する磁界強度の変動を少なくするために、温度特
性の良いもの、例えばアルニコ磁石、希土類コバ
ルト磁石を用いてもよいが、これらの磁石は一般
に高価であるので、価格的にはフエライト磁石を
用いるのが有利である。フエライト磁石は温度特
性は良くないが、本発明では永久磁石の外周面を
整磁鋼で覆うので、周囲温度の変化に対する補償
を行なうことができる。 As the above permanent magnet, in order to reduce fluctuations in magnetic field strength due to changes in ambient temperature, magnets with good temperature characteristics such as alnico magnets and rare earth cobalt magnets may be used, but these magnets are generally expensive. Therefore, it is advantageous to use ferrite magnets in terms of cost. Although ferrite magnets do not have good temperature characteristics, in the present invention, since the outer peripheral surface of the permanent magnet is covered with magnetic shunt steel, it is possible to compensate for changes in ambient temperature.
上記のように構成したフオーカスマグネツトに
おいて、永久磁石３のＮ極から流出した磁束は、
ヨークプレート１および２を通りＳ極に戻るの
で、ヨークプレートの内周面より電子ビームを集
束させる中心磁界が発生する。またヨークプレー
トの外周面より外周部漏洩磁界も発生する。良好
な集束効果をあげるためには、漏洩磁界をできる
だけ少なくし、効率よく中心磁界を発生させるこ
とが必要である。 In the focus magnet configured as described above, the magnetic flux flowing out from the N pole of the permanent magnet 3 is
Since the electron beam passes through yoke plates 1 and 2 and returns to the south pole, a central magnetic field that focuses the electron beam is generated from the inner peripheral surface of the yoke plate. Further, an outer peripheral leakage magnetic field is also generated from the outer peripheral surface of the yoke plate. In order to achieve a good focusing effect, it is necessary to reduce the leakage magnetic field as much as possible and efficiently generate the central magnetic field.
そこで本発明者等は種々検討した結果、ヨーク
プレートの外径寸法D1を永久磁石の外径寸法よ
りも小さくしかつD1／D2の値を特定の範囲、具
体的には0.85〜0.99の範囲に設定することによ
り、外周部漏洩磁界が少なくなり、高い中心磁界
が得られることが見出された。また本発明ではヨ
ークプレートの内径部につば部が設けられている
ので、永久磁石から発生する磁束はその内部に集
中し易くなり、外周部漏洩磁界をより少なくする
ことができる。 Therefore, as a result of various studies, the present inventors decided to make the outer diameter dimension D 1 of the yoke plate smaller than the outer diameter dimension of the permanent magnet, and to set the value of D 1 /D 2 within a specific range, specifically 0.85 to 0.99. It has been found that by setting the magnetic field in the range of , the leakage magnetic field at the outer circumference is reduced and a high central magnetic field can be obtained. Further, in the present invention, since the flange portion is provided on the inner diameter portion of the yoke plate, the magnetic flux generated from the permanent magnet is more likely to be concentrated inside the yoke plate, thereby making it possible to further reduce the leakage magnetic field at the outer circumferential portion.
第２図は、D1／D2と第１図のＸ点における磁
界強度、すなわち中心磁界の強度との関係を示す
図である。第２図においてハツチングを施した領
域が、電子ビームを有効に集束させることのでき
る中心磁界の範囲を示している。第２図から、
D1／D2の増加に伴つて中心磁界も増加し、D1／
D2が0.93近傍で中心磁界は最大となるが、D1／
D2がそれより大きくなると中心磁界は減少する
ことがわかる。すなわちD1／D2が特定の範囲に
あることにより高い中心磁界が得られる。 FIG. 2 is a diagram showing the relationship between D 1 /D 2 and the magnetic field strength at point X in FIG. 1, that is, the strength of the central magnetic field. The hatched area in FIG. 2 indicates the range of the central magnetic field that can effectively focus the electron beam. From Figure 2,
As D 1 /D 2 increases, the central magnetic field also increases, and D 1 /D 2 increases.
The central magnetic field is maximum when D 2 is around 0.93, but D 1 /
It can be seen that when D 2 becomes larger than that, the central magnetic field decreases. That is, a high central magnetic field can be obtained by having D 1 /D 2 within a specific range.
以上のように本発明によれば、小型かつ軽量で
あつて、しかも電子ビームを集束させるための中
心磁界を効率よく発生させることのできるフオー
カスマグネツトが得られる。 As described above, according to the present invention, it is possible to obtain a focus magnet that is small and lightweight, and that can efficiently generate a central magnetic field for focusing an electron beam.
第１図は本発明の一実施例に係るフオーカスマ
グネツトの縦断面図、第２図はヨークプレート外
径法と永久磁石外径寸法との比と中心磁界との関
係を示す図である。
１，２：ヨークプレート、１ａ，２ａ：つば
部、３：リング状永久磁石、４：整磁鋼。
FIG. 1 is a longitudinal sectional view of a focus magnet according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between the yoke plate outer diameter method, the ratio of the permanent magnet outer diameter dimension, and the central magnetic field. 1, 2: Yoke plate, 1a, 2a: collar portion, 3: ring-shaped permanent magnet, 4: magnetic shunt steel.
Claims (1)
記リング状永久磁石の外周面に固着された製磁鋼
と、前記リング状永久磁石の両端面に固着され、
中央に円孔を有しかつ前記リング状永久磁石の内
周面と接する環状のつば部を有する一対の円板状
のヨークプレートとを有するフオーカスマグネツ
トにおいて、前記ヨークプレートの外径寸法D1
と前記リング状永久磁石の外径寸法D2との比
（D1／D2）を0.85〜0.99の範囲としたことを特徴
とするフオーカスマグネツト。1. A ring-shaped permanent magnet magnetized in the axial direction, magnetic steel fixed to the outer peripheral surface of the ring-shaped permanent magnet, and fixed to both end surfaces of the ring-shaped permanent magnet,
In a focus magnet comprising a pair of disc-shaped yoke plates having a circular hole in the center and an annular flange in contact with the inner circumferential surface of the ring-shaped permanent magnet, the outer diameter dimension of the yoke plate D 1
and the outer diameter dimension D 2 of the ring-shaped permanent magnet (D 1 /D 2 ) is in the range of 0.85 to 0.99.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6577579A JPS55157844A (en) | 1979-05-28 | 1979-05-28 | Focusing magnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6577579A JPS55157844A (en) | 1979-05-28 | 1979-05-28 | Focusing magnet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55157844A JPS55157844A (en) | 1980-12-08 |
| JPH0138350B2 true JPH0138350B2 (en) | 1989-08-14 |
Family
ID=13296736
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6577579A Granted JPS55157844A (en) | 1979-05-28 | 1979-05-28 | Focusing magnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55157844A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007189910A (en) * | 2006-01-17 | 2007-08-02 | Shimizu Corp | Greening unit and greening system provided with the greening unit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5026274U (en) * | 1973-07-03 | 1975-03-26 |
-
1979
- 1979-05-28 JP JP6577579A patent/JPS55157844A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5026274U (en) * | 1973-07-03 | 1975-03-26 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55157844A (en) | 1980-12-08 |
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