JPH0622102B2 - Cathode ray tube - Google Patents
Cathode ray tubeInfo
- Publication number
- JPH0622102B2 JPH0622102B2 JP60052791A JP5279185A JPH0622102B2 JP H0622102 B2 JPH0622102 B2 JP H0622102B2 JP 60052791 A JP60052791 A JP 60052791A JP 5279185 A JP5279185 A JP 5279185A JP H0622102 B2 JPH0622102 B2 JP H0622102B2
- Authority
- JP
- Japan
- Prior art keywords
- ray tube
- cathode ray
- lens
- electron
- 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 - Lifetime
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
- H01J29/68—Magnetic lenses using permanent magnets only
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は永久磁石に成る電子レンズを用いた陰極線管の
改良に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an improvement of a cathode ray tube using an electron lens which is a permanent magnet.
［発明の概要］ 陰極線管において、少なくとも２個の別個に着磁された
リング永久磁石をＺ軸に沿って同一磁極方向に連結させ
た電子レンズを用い、その磁束密度分布の半値幅を永久
磁石の内径の８０％以上とすることにより、レンズ径を
変えることなく、球面収差の少ない電子レンズとしたも
のである。[Summary of the Invention] In a cathode ray tube, an electron lens in which at least two separately magnetized ring permanent magnets are connected in the same magnetic pole direction along the Z axis is used, and the half-value width of the magnetic flux density distribution is set to a permanent magnet. By setting the inner diameter to 80% or more, the electron lens has little spherical aberration without changing the lens diameter.
［従来の技術］ 従来のリング状永久磁石を使用する電子レンズとしては
第３図に示すように１個の磁石又は２個の磁石を相反す
る磁極方向に組み合わせたものが使用されていた。[Prior Art] As a conventional electron lens using a ring-shaped permanent magnet, as shown in FIG. 3, one magnet or a combination of two magnets in opposite magnetic pole directions has been used.
［発明が解決しようとする課題］ しかしこのような従来の電子レンズには、例えばブラウ
ン管の集束レンズとして使用した場合、電子ビームのス
ポットをある程度以上更に絞ろうとしても、球面収差が
大きくハレーションが現われる等の欠点があった。[Problems to be Solved by the Invention] However, in such a conventional electron lens, when it is used as a focusing lens of a cathode ray tube, for example, even if the spot of the electron beam is further narrowed down to a certain degree or more, a large spherical aberration causes halation. There were drawbacks such as.
本発明の目的は球面収差が小さく、ハレーションを生じ
ない電子レンズ用永久磁石を用いた陰極線管を提供する
ことである。An object of the present invention is to provide a cathode ray tube using a permanent magnet for an electron lens, which has a small spherical aberration and does not cause halation.
［問題点を解決するための手段］ 上記目的を達成するために、本発明による陰極線管は、
ブラウン管のネック部内に配された電子銃と、前記ネッ
ク部外周に配置され、前記電子銃より出射された電子ビ
ームを集束する電子ビーム集束装置を有する陰極線管で
あって、前記電子ビーム集束装置は、同一磁極方向に少
なくとも２個連結されたリング状永久磁石片を有し、前
記電子ビーム集束装置のＺ軸上の磁束密度分布の判値幅
は前記リング状永久磁石片の内径の８０〜２００％の値
であることを要旨とする。[Means for Solving the Problems] In order to achieve the above object, the cathode ray tube according to the present invention comprises:
A cathode ray tube having an electron gun arranged in a neck portion of a cathode ray tube and an electron beam focusing device arranged on the outer periphery of the neck portion and focusing an electron beam emitted from the electron gun, wherein the electron beam focusing device is , The ring-shaped permanent magnet pieces connected in the same magnetic pole direction, and the judgment width of the magnetic flux density distribution on the Z axis of the electron beam focusing device is 80 to 200% of the inner diameter of the ring-shaped permanent magnet pieces. The gist is that it is the value of.
［作用］ 以下にまず、本発明の陰極線管に使用される電子レンズ
用永久磁石の基本的作用の原理から説明する。[Operation] First, the principle of the basic operation of the permanent magnet for an electron lens used in the cathode ray tube of the present invention will be described.
レンズ系の球面収差はレンズ径とレンズ焦点距離に関係
するが、レンズ径は物理的制約を受けることが多い。し
たがって、ここではレンズ強度（焦点距離）のみについ
て論ずるが、定性的には光学レンズとの対比で理解でき
るので、まず光学レンズの場合を説明する。The spherical aberration of the lens system is related to the lens diameter and the lens focal length, but the lens diameter is often physically restricted. Therefore, only the lens strength (focal length) will be discussed here, but since it can be qualitatively understood by comparison with the optical lens, the case of the optical lens will be described first.
光学レンズの場合、球面収差係数（ＣＳ）は、次式のよ
うに、焦点距離（ｆ）の３乗の逆数に比例する。In the case of an optical lens, the spherical aberration coefficient (C S ) is proportional to the reciprocal of the cube of the focal length (f), as in the following equation.
ＣＳ∝ １／ｆ３ したがって、Ｎ個の弱いレンズ（焦点距離Ｎｆ）を組み
合わせれば、その合成レンズの球面収差は となり、１／Ｎ2となる。カメラなどはこれを応用して
いる。C S ∝ 1 / f 3 Therefore, if N weak lenses (focal length Nf) are combined, the spherical aberration of the synthetic lens will be And becomes 1 / N 2 . Cameras and the like apply this.
この原理を陰極線管に使用される電子レンズ用永久磁石
で実現したのが本発明の趣旨である。永久磁石の磁束密
度分布は、反磁界成分があるため、第２図に示すように
なるが、その焦点距離は となる。図中両端に矢印を付した線分は半値幅（ＢW）
を示す。The purpose of the present invention is to realize this principle with a permanent magnet for an electron lens used in a cathode ray tube. The magnetic flux density distribution of the permanent magnet has a demagnetizing field component, so it is as shown in Fig. 2, but its focal length is Becomes The line segment with arrows at both ends in the figure is the full width at half maximum (B W ).
Indicates.
問題となるのは作用領域であるＢ(z)（磁束分布）であ
るが主な作用領域は、正分布なので正分布の半値幅をＢ
(z)のパラメータとする。半値幅（ＢW）を増やすには、
第３図からわかるようにレンズ径（Ｌ）と磁石幅（Ｍ）
が考えられる。The problem is B (z) (magnetic flux distribution), which is the action area, but the main action area is the positive distribution, so the half-value width of the positive distribution is B
It is a parameter of (z). To increase the full width at half maximum (B W ),
As can be seen from FIG. 3, lens diameter (L) and magnet width (M)
Can be considered.
第４図は、任意の区間で半値幅（ＢW）とレンズ径（磁
石の内径＝Ｌ）の関係を実験で求めたものである。FIG. 4 shows the relationship between the full width at half maximum (B W ) and the lens diameter (the inner diameter of the magnet = L) obtained by an experiment in an arbitrary section.
ＢW＝０．５５Ｌ レンズ径を大きくすることは半値幅を大きくする上で可
成りの効果があるが、制約が多く、変えられないので、
これもパラメータに加える。すなわち、 Ｈ＝半値幅／レンズ径 を新しいＢ(z)のパラメータとする。B W = 0.55 L Increasing the lens diameter has a considerable effect on increasing the half width, but there are many restrictions and it cannot be changed.
This is also added to the parameter. That is, H = half-width / lens diameter is used as a new parameter for B (z).
第５図の直線ａは、Ｈを大きくするためのもう一方のパ
ラメータである磁石幅との関係を実験的に求めたもの
で、同図から近似的に下式が得られる。The straight line a in FIG. 5 is an experimentally obtained relation with the magnet width, which is the other parameter for increasing H, and the following equation is approximately obtained from the same figure.
Ｈ＝０．００４Ｍ＋０．４９ この式から明らかなように磁石幅の効果は小さい。H = 0.004M + 0.49 As is clear from this formula, the effect of the magnet width is small.
そこで、第６図に示すように、例えば、２個の別個の着
磁された弱い永久磁石１，２を磁極板３を介して同一磁
極方向に連結して、Ｈとの関係を実験的に求めたのが第
５図直線ｂで、これより下式が近似的に求められる。Therefore, as shown in FIG. 6, for example, two separate weakly magnetized permanent magnets 1 and 2 are connected in the same magnetic pole direction via the magnetic pole plate 3, and the relationship with H is experimentally determined. The line b shown in FIG. 5 was obtained, and the following equation is approximately obtained from this.
Ｈ＝０．０１Ｍ＋０．５３ 上記式からわかるように第６図の磁石構成とすれば、レ
ンズ径に関係なくＨを大幅に増やすことが可能となる。H = 0.01M + 0.53 As can be seen from the above equation, with the magnet configuration shown in FIG. 6, H can be significantly increased regardless of the lens diameter.
［実施例］ 第１図は本発明による電子レンズを含むブラウン管の一
実施例における電子銃付近の断面図で、４はカソード、
５は第１グリッド、６は第２グリッド、７はアノードで
ある。アノード７の前方には第６図に示す電子レンズ用
永久磁石１，２が配設され、夫々の磁石に設けた磁極板
３は微調節のためのスペーサの役も果たす。またこれに
代えて微調整コイルを設けることもできる。第７図は第
１図に示す電子レンズによるＺ軸上の磁束密度分布を実
線で示す。比較のために単独永久磁石の場合の磁束密度
分布を破線で示す。[Embodiment] FIG. 1 is a sectional view of the vicinity of an electron gun in an embodiment of a cathode ray tube including an electron lens according to the present invention, and 4 is a cathode,
Reference numeral 5 is a first grid, 6 is a second grid, and 7 is an anode. Electron lens permanent magnets 1 and 2 shown in FIG. 6 are arranged in front of the anode 7, and the magnetic pole plate 3 provided on each magnet also serves as a spacer for fine adjustment. Alternatively, a fine adjustment coil may be provided instead. FIG. 7 shows the magnetic flux density distribution on the Z axis by the electron lens shown in FIG. 1 by a solid line. For comparison, the magnetic flux density distribution in the case of a single permanent magnet is shown by a broken line.
第８図は第５図ｂに示すＨと球面収差係数比（ＣSR）と
の関係を実験で求めたものである。ＣSRはＨの増大とと
もに減少し、０．８以上で飽和することがわかった。FIG. 8 shows the relationship between H and the spherical aberration coefficient ratio (C SR ) shown in FIG. It has been found that C SR decreases with an increase in H and saturates above 0.8.
Ｈ＝０．５とＨ＝１．０を比較すると球面収差係数は７
０％改善される。このことから本発明の陰極線管用の電
子レンズとして、実用的にはＺ軸上の磁束密度分布の半
値幅が永久磁石１，２の内径の８０〜２００％の値を有
するようにするのが有効であること明らかである。When H = 0.5 and H = 1.0 are compared, the spherical aberration coefficient is 7
It is improved by 0%. From this, it is practically effective for the cathode ray tube electron lens of the present invention that the half-value width of the magnetic flux density distribution on the Z axis has a value of 80 to 200% of the inner diameters of the permanent magnets 1 and 2. It is clear that
第９図は本発明の陰極線管における電子レンズのビーム
集束特性を実線で示し、比較のために単独磁石によるビ
ーム集束特性を破線で示す。FIG. 9 shows the beam focusing characteristic of the electron lens in the cathode ray tube of the present invention by a solid line, and the beam focusing characteristic by a single magnet is shown by a broken line for comparison.
［発明の効果］ 以上説明した通り、本発明によれば、永久磁石を同一磁
極方向に少なくとも二つ連結して使用することによって
収差が小さく、ハレーションを起こさない電子レンズを
用いた陰極線管を得ることができる。[Effects of the Invention] As described above, according to the present invention, by using at least two permanent magnets connected in the same magnetic pole direction, a cathode ray tube using an electron lens having a small aberration and causing no halation is obtained. be able to.
第１図は本発明による電子レンズを含むブラウン管の一
実施例における電子銃付近の断面図、第２図は単独永久
磁石の磁束密度分布図、第３図はリング状永久磁石の磁
束分布図、第４図は半値幅（ＢW）と磁石内径（Ｌ）の
関係を示すグラフ、第５図は磁石幅（Ｍ）と半値幅を表
わすパラメータ（Ｈ）の関係を示すグラフ、第６図は本
発明による陰極線管の電子レンズの側面図、第７図は本
発明による陰極線管の電子レンズにおける磁束密度分布
図、第８図は半値幅を表わすパラメータ（Ｈ）と球面収
差係数比（ＣSR）の関係を示すグラフ、第９図は永久磁
石によるビーム集束特性を示すグラフである。 １，２……永久磁石、３……磁極板、４……カソード、
５……第１グリッド、６……第２グリッド、７……アノ
ード。FIG. 1 is a sectional view of the vicinity of an electron gun in an embodiment of a cathode ray tube including an electron lens according to the present invention, FIG. 2 is a magnetic flux density distribution diagram of a single permanent magnet, and FIG. 3 is a magnetic flux distribution diagram of a ring-shaped permanent magnet. FIG. 4 is a graph showing the relationship between the half width (B W ) and the magnet inner diameter (L), FIG. 5 is a graph showing the relationship between the magnet width (M) and the parameter (H) representing the half width, and FIG. FIG. 7 is a side view of the electron lens of the cathode ray tube according to the present invention, FIG. 7 is a magnetic flux density distribution diagram in the electron lens of the cathode ray tube according to the present invention, and FIG. 8 is a parameter (H) representing a half width and a spherical aberration coefficient ratio (C SR). ), And FIG. 9 is a graph showing the beam focusing characteristic of the permanent magnet. 1, 2 ... Permanent magnets, 3 ... Pole plates, 4 ... Cathode,
5 ... 1st grid, 6 ... 2nd grid, 7 ... Anode.
Claims (1)
と、 前記ネック部外周に設置され、前記電子銃より出射され
た電子ビームを集束する電子ビーム集束装置を有する陰
極線管であって、 前記電子ビーム集束装置は、同一磁極方向に少なくとも
２個連結されたリング状永久磁石片を有し、 前記電子ビーム集束装置のＺ軸上の磁束密度分布の半値
幅は前記リング状永久磁石片の内径の８０〜２００％の
値であることを特徴とする陰極線管。1. A cathode ray tube comprising: an electron gun arranged in a neck portion of a cathode ray tube; and an electron beam focusing device installed on the outer circumference of the neck portion for focusing an electron beam emitted from the electron gun. The electron beam focusing device has at least two ring-shaped permanent magnet pieces connected in the same magnetic pole direction, and the half-value width of the magnetic flux density distribution on the Z axis of the electron beam focusing device is the inner diameter of the ring-shaped permanent magnet piece. Of 80 to 200% of the cathode ray tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60052791A JPH0622102B2 (en) | 1985-03-15 | 1985-03-15 | Cathode ray tube |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60052791A JPH0622102B2 (en) | 1985-03-15 | 1985-03-15 | Cathode ray tube |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61211940A JPS61211940A (en) | 1986-09-20 |
| JPH0622102B2 true JPH0622102B2 (en) | 1994-03-23 |
Family
ID=12924655
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60052791A Expired - Lifetime JPH0622102B2 (en) | 1985-03-15 | 1985-03-15 | Cathode ray tube |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0622102B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62290048A (en) * | 1986-05-01 | 1987-12-16 | Hitachi Metals Ltd | Forcus magnet |
| JPH07118281B2 (en) * | 1987-11-30 | 1995-12-18 | 日立金属株式会社 | Focus magnet |
| US5113162A (en) * | 1991-05-23 | 1992-05-12 | Hitachi Metals, Ltd. | Focus magnet with separate static and dynamic control coils |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55143761A (en) * | 1979-04-24 | 1980-11-10 | Hitachi Metals Ltd | Focus magnet |
| JPS5787462U (en) * | 1980-11-18 | 1982-05-29 | ||
| JPS57113545A (en) * | 1981-01-07 | 1982-07-15 | Sony Corp | Cathode ray tube apparatus |
| JPS57132645A (en) * | 1981-02-10 | 1982-08-17 | Toshiba Corp | Cathode-ray tube |
| JPS59215642A (en) * | 1983-05-23 | 1984-12-05 | Toshiba Corp | Electromagnetic focusing cathode ray tube |
-
1985
- 1985-03-15 JP JP60052791A patent/JPH0622102B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61211940A (en) | 1986-09-20 |
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