JPS6149852A - Printing head for dot printer - Google Patents

Abstract

PURPOSE:To reduce the capacity of a transistor for auxiliary demagnetizing coils by a method in which main demagnetizing coils are provided on the periphery of a focusing pole column, auxiliary demagnetizing coils are provided to each of the pole columns, and a small current is flowed in the auxiliary demagnetizing coil for selection of printing needles. CONSTITUTION:For the conventional constitution of internal permanent magnet type, main demagnetizing coils 31 are set on the periphery of a focusing pole column 11. Auxiliary demagnetizing coils 10a are provided to each of the pole columns 9. The turns number and drive current of the coil are set up properly in such a way as to enable main demagnetizing magnetic flux to generate in the coil 31 and also as much as demagnetizing magnetic flux as to select printing needles to generate in the coil 10a. In short, in the case of the printing head of 24 pins, since driving can be made by only one of 24 coils 10a, the capacity of the transistors can be reduced, and therefore, transistor array and IC devices can be obtained.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、各種コンピュータの出力端末機として使用さ
れているドツトプリンタ用印字ヘッドに関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a print head for a dot printer used as an output terminal for various computers.

従来例の構成とその問題点 近年、各種コンピュータの進展により、各種用紙に印字
が可能で、かつ低価格のドツトプリンタが多く利用され
、より一層の小形化、低価格化が強く要望されている。Conventional configurations and their problems In recent years, with the advancement of various computers, low-cost dot printers that can print on various types of paper have come into widespread use, and there is a strong demand for further miniaturization and lower prices.

以下に従来のドツトプリンタ用印字ヘッド（以下、印字
ヘッドと略す）について、第１図ａ、ｂ、第２図、第３
図ａｌ　ｂ　％および第４図により説明３べ− する。The conventional print heads for dot printers (hereinafter abbreviated as print heads) are shown below in Figures 1a and b, Figures 2 and 3.
The explanation is based on Figure 3 and Figure 4.

第１図ａ、ｂは、内磁永久磁石型の従来の印字ヘッドの
概略平面断面図、および概略側断面図であり、第２図は
特願昭５６−１３４２４７号に記載の従来の外磁永久磁
石型の印字ヘッドの概略側断面図である。尚、第２図の
印字ヘッドについては、磁気干渉防止コイル２３のみに
ついて説明し、その他は説明を省略する。次に第３図ａ
、ｂは磁気干渉の状態を示す印字ヘッドの模式図であり
第４図は、２４ピン印字ヘッドについての磁気干渉特性
図である。FIGS. 1a and 1b are a schematic plan sectional view and a schematic side sectional view of a conventional internal permanent magnet type print head, and FIG. FIG. 1 is a schematic side sectional view of a permanent magnet type print head. Regarding the print head shown in FIG. 2, only the magnetic interference prevention coil 23 will be explained, and the explanation of the others will be omitted. Next, Figure 3a
, b are schematic diagrams of the print head showing the state of magnetic interference, and FIG. 4 is a magnetic interference characteristic diagram for the 24-pin print head.

第１図において、１は印字針、２は印字針１の一端を案
内する案内孔を有する軸受、３は軸受２を保持する筐体
、４は印字針１の他端に固着された作動体、６は作動体
４の一端に固着された板ばね、６はスペーサ、７はスペ
ーサ６を介して板ばね５の一端を支持する支持リング、
８は支持リング７を略円周状に配設する基板、９は支持
リング７の内側で基板８上に配され、かつ板ばね５と対
向する面を有する磁極柱、１０は磁極柱９の外周に巻か
れた消磁コイル、１１は基板８の中心部に配された収束
磁極柱、１２は作動体４に磁気力を及ぼすように収束磁
極柱１１の上面に接合された永久磁石、１３は永久磁石
１２の上面に接合された継鉄板を示している。ここで、
板ばね５および作動体４は、複数個略円環状に配置され
、磁極柱９は、板ばね６と対向するように配置されてい
る。In FIG. 1, 1 is a printing needle, 2 is a bearing having a guide hole for guiding one end of the printing needle 1, 3 is a housing that holds the bearing 2, and 4 is an actuating body fixed to the other end of the printing needle 1. , 6 is a leaf spring fixed to one end of the operating body 4, 6 is a spacer, 7 is a support ring that supports one end of the leaf spring 5 via the spacer 6,
Reference numeral 8 denotes a substrate on which the support ring 7 is disposed substantially circumferentially, 9 a magnetic pole column arranged on the substrate 8 inside the support ring 7 and having a surface facing the leaf spring 5, 10 a magnetic pole column of the magnetic pole column 9; A degaussing coil wound around the outer circumference, 11 a converging magnetic pole column arranged at the center of the substrate 8, 12 a permanent magnet bonded to the upper surface of the converging magnetic pole column 11 so as to exert a magnetic force on the operating body 4, and 13 a permanent magnet A yoke plate joined to the upper surface of the permanent magnet 12 is shown. here,
A plurality of leaf springs 5 and operating bodies 4 are arranged in a substantially annular shape, and the magnetic pole column 9 is arranged to face the leaf spring 6.

捷た、継鉄板１３には、作動体４を抱き込むように、複
数の先端柱１４を形成し、継鉄板１３と先端柱１４とで
継鉄柱が構成される。A plurality of tip columns 14 are formed on the cut yoke plate 13 so as to enclose the actuating body 4, and the yoke plate 13 and the tip columns 14 constitute a yoke column.

以上のように構成された従来の印字ヘッドについて、以
下その動作を説明する。まず、通常は、永久磁石１２の
磁束が、継鉄板１３および先端柱１４を介して、作動体
４に導かれ、板ばね６を通って、磁極柱９．基板８．収
束磁極柱１１を帰環して、永久磁石１２に戻る。したが
って、作動体４は板ばね５の反発力に打ち勝って吸引さ
れ、板ばね６はたわんだ状態と々っている。次に消磁コ
イル１０に電流を通すと、永久磁石１２の磁束が打ち消
され作動体４の吸引力が減少するため、板５ベーノ゛ ばね６の復元力により、作動体４は、図中上方に加速き
れる。この時、印字針１も上方に加速されるため、軸受
２より突出し、インクリボンを衝撃し、点状の印字を行
う。ζらに消磁コイル１０の電流を止めると、上述の如
く、作動体４は、永久磁石１２の磁束により吸引され元
の位置に復帰する。以上の動作を１サイクルとし、印字
ヘッドを用紙に対し左右に走査しながら、印字針１を適
時に動作きせる事により点状のマトリクス印字が行なわ
れる。The operation of the conventional print head configured as described above will be described below. First, normally, the magnetic flux of the permanent magnet 12 is guided to the actuating body 4 via the yoke plate 13 and the tip post 14, passes through the leaf spring 6, and then passes through the magnetic pole post 9. Substrate 8. The converging magnetic pole column 11 is returned to the permanent magnet 12. Therefore, the actuating body 4 overcomes the repulsive force of the leaf spring 5 and is attracted, and the leaf spring 6 remains in a bent state. Next, when current is passed through the degaussing coil 10, the magnetic flux of the permanent magnet 12 is canceled and the attractive force of the actuating body 4 is reduced, so the actuating body 4 is moved upward in the figure by the restoring force of the plate 5 and vane spring 6. I can accelerate. At this time, the printing needle 1 is also accelerated upward, so that it protrudes from the bearing 2, impacts the ink ribbon, and performs dot printing. When the current in the degaussing coil 10 is stopped at ζ, the actuating body 4 is attracted by the magnetic flux of the permanent magnet 12 and returns to its original position, as described above. The above operations constitute one cycle, and dotted matrix printing is performed by moving the printing needle 1 at appropriate times while scanning the print head left and right across the paper.

しかし々がら、上記従来の印字ヘッドは、磁気干渉によ
り、作動体４の動作電流が大となっていた。磁気干渉の
状態について第３図により説明する。第３図ａにおいて
、２６は継鉄柱、２７は永久磁石、２Ｂａ、２８ｂ、２
８ｃは磁極柱、２９ａ。However, in the conventional print head described above, the operating current of the operating body 4 is large due to magnetic interference. The state of magnetic interference will be explained with reference to FIG. In Fig. 3a, 26 is a yoke column, 27 is a permanent magnet, 2Ba, 28b, 2
8c is a magnetic pole column, 29a.

２９ｂ　、２９ｃは消磁コイル、３０ａ、３０ｂ。29b and 29c are demagnetizing coils, 30a and 30b.

３０ｃは作動体を示す。ここで板ばねは図示してい々い
Ｏ第３図ａにおいて作動体３Ｑａ、３０ｂ。30c indicates an operating body. Here, the leaf springs are shown as operating bodies 3Qa and 30b in FIG. 3a.

３０Ｃは、永久磁石２７の磁束により、各々磁極柱２８
ａ　、２８ｂ　、２８ｃに吸引されている。こ　Ａ− の吸引磁束の流れ方を作動体３０ｂについて、Ａで表わ
す。つまり、永久磁石２７の磁束は、磁極柱２８ｂを通
り、作動体３０ｂの図中下面より側面を通って継鉄柱２
６を帰還して永久磁石２７に戻る。次に第３図すに磁束
Ａを打ち消すために消磁コイル２９ｂに消磁電流を流し
た時の消磁磁束の流れをＢおよびＣで示す。ここで、消
磁磁束Ｂば、磁極柱２８ｂ２作動体３０ｂ、継鉄柱２６
を通り、永久磁石２７を介して磁極柱２８ｂに帰還する
ループを有する。しかし永久磁石２７の透磁率は、一般
に空気と同程度の非常に小さい値であるため、上記のル
ープは磁気抵抗が大きい。そのため、作動体３０ｂを通
り、作動体３０ａ、および３０ｃに捷わり込み、磁極柱
２８ａ、および２８ｃを帰還して、磁極柱２８ｂに至る
洩れ磁束が発生する。しかしこの点線で示す洩れ磁束の
ループＣは、磁極柱２８ａ、２８ｃの磁束り、Ｅに対し
ては、これと同じ向き、つまシ吸引磁束を強める方向に
なる。したがって、消磁コイル２９ａ。30C, each magnetic pole column 28 is caused by the magnetic flux of the permanent magnet 27.
It is attracted to a, 28b, and 28c. The flow of this magnetic flux A- is represented by A with respect to the actuating body 30b. In other words, the magnetic flux of the permanent magnet 27 passes through the magnetic pole column 28b, passes from the lower surface of the actuator 30b to the side surface of the yoke column 28b, and passes through the yoke column 28b.
6 and return to the permanent magnet 27. Next, in FIG. 3, the flows of the demagnetizing magnetic flux when a demagnetizing current is passed through the demagnetizing coil 29b to cancel the magnetic flux A are shown by B and C. Here, the demagnetizing magnetic flux B, the magnetic pole column 28b2, the operating body 30b, the yoke column 26
It has a loop that returns to the magnetic pole column 28b via the permanent magnet 27. However, since the magnetic permeability of the permanent magnet 27 is generally very small, comparable to that of air, the above-mentioned loop has a large magnetic resistance. Therefore, leakage magnetic flux is generated that passes through the actuating body 30b, twists into the actuating bodies 30a and 30c, returns through the magnetic pole columns 28a and 28c, and reaches the magnetic pole column 28b. However, the loop C of the leakage magnetic flux shown by the dotted line is in the same direction as the magnetic flux E of the magnetic pole columns 28a and 28c, which is a direction that strengthens the magnetic flux attracted by the pole. Therefore, the demagnetizing coil 29a.

２９ｂ、２９Ｃに同時に電流を流すと上述の洩れ７　′
″− 磁束ループが、互いに影響を及ぼし合うため、駆動ピン
数が増すにつれて、１ピンあたりの最低駆動電流も増し
てし脣う。この状態を第４図に示す。When current is applied to 29b and 29C at the same time, the above leakage 7'
''- Because the magnetic flux loops influence each other, as the number of drive pins increases, the minimum drive current per pin also increases. This situation is shown in FIG.

これは、２４ピン印字ヘッドについて測定値の一例であ
り、横軸には駆動ピン数、縦軸には、任意の１ピンにつ
いて、その１ピンのみ駆動した時の最低駆動電流を１と
し、順時駆動ピン数を増した時の前記任意の１ピンにつ
いての規格化駆動電流を表わしている。この図から明ら
かな様に、一般に駆動ビン数２４ピンの場合は、１ピン
のみの駆動に対して、１ピンあたり約２倍の電流を必要
とする。このため、２４ピン駆動の場合２〜４〔Ａ〕の
大電流を必要とし、印字ヘッド駆動用トランジスタは大
容量のものを使わざるを得す、印字ヘッド駆動回路のコ
スト低減の大きな障害となっていた。This is an example of a measured value for a 24-pin print head. The horizontal axis shows the number of driving pins, and the vertical axis shows the lowest driving current when only that one pin is driven as 1. It represents the normalized drive current for the arbitrary pin when the number of drive pins is increased. As is clear from this figure, in general, when the number of drive bins is 24 pins, approximately twice the current per pin is required for driving only one pin. For this reason, in the case of 24-pin drive, a large current of 2 to 4 [A] is required, and the print head drive transistor must have a large capacity, which is a major obstacle to reducing the cost of the print head drive circuit. was.

次に第２図は、従来の外磁永久磁石型の印字ヘッドで、
永久磁石２１の内側に磁気干渉防止コイル２３を巻いた
もので、１５は印字針、１６は作動体、１７は板ばね、
１８は継鉄柱、１９はスペーサ、２０はリング、２１は
永久磁石、２２は基板、２３は磁気干渉防止コイル、２
４は磁極柱、２５は消磁コイルである。ここで磁気干渉
防止コイル２３は、消磁コイル２５の全数と直列接続さ
れているため、印字ピン数に拘わらずかつ、消磁コイル
２５に印加する電圧や１駆動時間を変えることなく均一
な印字力が得られるものである。しかし、外磁永久磁石
型の印字ヘッドは、永久磁石の洩れ磁束が大きい等の欠
点があった。きらに、前述の様に、磁気干渉防止コイル
２３が、消磁コイル２５の全数と直列接続きれているた
め、消磁コイル２５のインダクタンスが犬となり、シタ
がって、消磁コイル２５に流す電流の立ち上りが遅くな
るため、作動体１６の応答性が低下し結局印字速度が低
下するという欠点があった。これをさけるためには、駆
動電圧を高くしなければならないが、これは、前述の印
字ヘッド駆動トランジスタの大容量化を招くという欠点
を有していた。Next, Figure 2 shows a conventional external permanent magnet type print head.
A magnetic interference prevention coil 23 is wound inside a permanent magnet 21, 15 is a printing needle, 16 is an actuating body, 17 is a leaf spring,
18 is a yoke pole, 19 is a spacer, 20 is a ring, 21 is a permanent magnet, 22 is a substrate, 23 is a magnetic interference prevention coil, 2
4 is a magnetic pole column, and 25 is a degaussing coil. Here, since the magnetic interference prevention coil 23 is connected in series with all the degaussing coils 25, uniform printing force can be achieved regardless of the number of printing pins and without changing the voltage applied to the demagnetizing coils 25 or the driving time. That's what you get. However, the external permanent magnet type print head has drawbacks such as large leakage magnetic flux of the permanent magnet. Furthermore, as mentioned above, since the magnetic interference prevention coil 23 is not connected in series with all the degaussing coils 25, the inductance of the degaussing coil 25 becomes a dog, and the current flowing through the degaussing coil 25 rises. As a result, the responsiveness of the operating body 16 decreases, resulting in a decrease in printing speed. In order to avoid this, it is necessary to increase the driving voltage, but this has the drawback of increasing the capacity of the print head driving transistor mentioned above.

発明の目的 本発明は、上記従来の欠点を除去するものでありベー／
゛ す、印字ヘッド駆動トランジスタを小容量化し駆動回路
の低価格化を目的とするものである。OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned drawbacks of the prior art and
The purpose is to reduce the capacity of the print head drive transistor and reduce the cost of the drive circuit.

発明の構成 上記目的を達成するために本発明は、印字針を有する複
数の作動体と、前記複数の作動体の一端にそれぞれ固着
された板ばねと、前記板ばねの一端を支持する支持リン
グと前記支持リングを略円周状に配設する基板と、前記
支持リングの内側で前記基板の上に配されかつ前記板ば
ねと対向する面を有する複数の磁極柱および副消磁コイ
ルと、前記基板の中心部に配された収束磁極柱と、前記
作動体に磁気力を及ぼすように、前記収束磁極柱の一面
に設けられた永久磁石と、前記永久磁石の他面に設けら
れた継鉄柱と、前記収束磁極柱と、前記継鉄柱のいずれ
か一方に主消磁コイルを配した構成となっており、これ
により前記主消磁コイルと前記副消磁コイルを各々独立
して通電し、前記副消磁コイルのうちいずれかを通電す
る時のみ前記主消磁コイルに通電し、前記主消磁コイル
の電流を、駆動ピン数が多い時は犬、少ない時は小１０
ハ、−〕 とするもので、印字ヘッド駆動トランジスタを小容量化
し、駆動回路を低価格化する事ができる。Structure of the Invention In order to achieve the above object, the present invention provides a plurality of actuating bodies having printing needles, a leaf spring fixed to one end of the plurality of actuating bodies, and a support ring supporting one end of the leaf spring. a substrate on which the support ring is disposed substantially circumferentially; a plurality of magnetic pole columns and a sub-demagnetizing coil disposed on the substrate inside the support ring and having a surface facing the leaf spring; A converging magnetic pole column arranged at the center of the substrate, a permanent magnet provided on one side of the converging magnetic pole column so as to exert magnetic force on the operating body, and a yoke column provided on the other side of the permanent magnet. and a main demagnetizing coil is disposed on either the converging magnetic pole column or the yoke column, whereby the main demagnetizing coil and the sub-demagnetizing coil are energized independently, and the sub-demagnetizing coil is energized independently. The main degaussing coil is energized only when any one of the coils is energized, and the current of the main degaussing coil is set to 100% when the number of drive pins is large, and 10% when there are few.
C,-], the capacity of the print head drive transistor can be reduced, and the cost of the drive circuit can be reduced.

実施例の説明 以下本発明の一実施例を、第５図ａ　、　ｂ、第６図お
よび第７図により説明する。第６図ａ、ｂは本発明の一
実施例によるドツトプリンタ用印字ヘッド（以下単に印
字ヘッドという）の概略平面断面図および概略側断面図
であり、第６図ば２４ビン印字ヘッドについての駆動回
路、第７図ば２４ビン印字ヘッドについての主消磁コイ
ルの駆動電圧制御の一実施例を示す。第５図ａ、ｌ）に
おいて、第１図ａ、ｔ）に示す内磁永久磁石型の従来の
印字ヘッドと異なるのは、３１主消磁コイルのみで、そ
の他の構成は同じであるので説明は省略する。DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 5a and 5b, FIGS. 6 and 7. 6a and 6b are a schematic plan sectional view and a schematic side sectional view of a print head for a dot printer (hereinafter simply referred to as print head) according to an embodiment of the present invention, and FIG. 6 is a drive circuit for a 24-bin print head. FIG. 7 shows an embodiment of drive voltage control of the main degaussing coil for a 24-bin print head. In FIG. 5 a, l), the only difference from the internal permanent magnet type conventional print head shown in FIG. Omitted.

第５図すにおいて、収束磁極柱１１の外周部に主消磁コ
イル３１が配されており、各磁極柱９にはそれぞれ副消
磁コイル１０ａが配されている。In FIG. 5, a main demagnetizing coil 31 is arranged on the outer periphery of the converging magnetic pole column 11, and a sub-demagnetizing coil 10a is arranged in each magnetic pole column 9, respectively.

次に第６図においてＱｏは主消磁コイル用トランジスタ
、３２は主消磁コイル、Ｑ１〜Ｑ２４は、副消磁コイル
用トランジスタ、３３〜５６は副消１１べ。Next, in FIG. 6, Qo is a main demagnetizing coil transistor, 32 is a main demagnetizing coil, Q1 to Q24 are sub demagnetizing coil transistors, and 33 to 56 are sub demagnetizing coils.

磁コイルを示している。ここで主消磁コイル３２の巻き
数および駆動電流を適当に設定し、主たる消磁磁束は、
主消磁コイル３２で発生させれば、副消磁コイル３３〜
５６には印字針を選択するだけの消磁磁束を発生させる
だけで良い。つまり、副駆動用としてトランジスタ０１
〜Ｑ１２　は極めて小さい容量のもので良く、トランジ
スタ・アレイ。A magnetic coil is shown. Here, the number of turns and drive current of the main demagnetizing coil 32 are set appropriately, and the main demagnetizing magnetic flux is
If it is generated by the main demagnetizing coil 32, the sub demagnetizing coil 33~
56, it is sufficient to generate a demagnetizing magnetic flux sufficient to select the printing needle. In other words, transistor 01 is used for sub-drive.
~Q12 can be of extremely small capacitance and is a transistor array.

もしくは１．Ｃ，化する事も可能である。Or 1. It is also possible to convert it into C.

また、副消磁コイル３３〜５６のうちいずれかを通電す
る時のみ、主消磁コイル３２に通電すればより省電力化
を計ることができる。Further, power can be further saved by energizing the main demagnetizing coil 32 only when any one of the sub-demagnetizing coils 33 to 56 is energized.

きらに、例えば第７図に示すように、駆動ピン数に応じ
て、主消磁コイル３２の駆動電流Ｅｍを制御すれば、よ
り印字力の変動を少くしかつ省電力化する事が可能とな
る。For example, as shown in FIG. 7, if the drive current Em of the main degaussing coil 32 is controlled according to the number of drive pins, it is possible to further reduce fluctuations in printing force and save power. .

尚、主消磁コイル３１は収束磁極柱１１に設けたが、継
鉄柱に設けてもよく、収束磁極柱１１と継鉄柱の両方に
設けてもよい。Although the main degaussing coil 31 is provided on the converging magnetic pole column 11, it may be provided on the yoke column, or may be provided on both the converging magnetic pole column 11 and the yoke column.

発明の効果 以上のように本発明の印字ヘッドによれば、次の効果が
得られる。Effects of the Invention As described above, the print head of the present invention provides the following effects.

（１）副消磁コイルは、単に印字針の選択をするのみで
あるので、極めて小さい電流で印字ヘッドを駆動できる
ため、副消磁コイル用トランジスタを小容量化でき、従
来２４ピン印字ヘッドの場合は２４ケのトランジスタを
用いていたのに対し、これをトランジスタアレイもしく
は１．Ｃ化する事ができる。(1) Since the sub degaussing coil simply selects the printing needle, the print head can be driven with an extremely small current, so the capacity of the transistor for the sub degaussing coil can be reduced, compared to the conventional 24-pin print head. Instead of using 24 transistors, this can be replaced by a transistor array or 1. It can be converted into C.

（２）印字力の変動を少くする事ができる。(2) Fluctuations in printing power can be reduced.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図ａ、ｂは、内磁永久磁石型の従来の印字ヘッドの
概略平面断面図、および概略側断面図、第２図は従来の
外磁永久磁石型の印字ヘッドの概略側断面図、第３図ａ
、ｂは磁気干渉の状態を示す印字ヘッドの模式図、第４
図は２４ピン印字ヘッドについての磁気干渉特性図、第
５図ａ、ｂは本発明の一実施例における印字ヘッドの概
略平面断面図、および概略側断面図、第６図は本発明の
一実施例における印字ヘッドの駆動回路図、第７図は主
消磁電流の制御方法を示す図である。 １３べ　。 １・・・・・・印字針、２・・・・・軸受、３・・・・
・筐体、４・・・・・作動体、５・・・・・・板ばね、
６・・・・スペーサ、７・・・支持リング、８・・・・
・・基板、９・・・・・・磁極柱、１゜・・・・・消磁
コイル、１０　ａ・・・・・・副消磁コイル、１１・・
・・・収束磁極柱、１２・・・・永久磁石、１３・・川
・継鉄板、１４・・・・・・先端柱、３１・・・・・・
主消磁コイル。 代理人の氏名　弁理士　中　尾　敏　男　はが１名第１
図 第２図 第３図 （ｃＬ） ＣＧ 第４図 １６区ナカと・ン朝く 第５図 第６図 ｏＮｏｕ　　　　　　　３２ ■［−σ０ ＯＮ 」−〇＋−３３ ＯＮ　　　　　　　　＝　　　　　３４−■−〇２　　
　　　＼ ｌ：１ ｊ ■ ｊ ｊ ＯＮ　　　　　　　ｌ　　　　　　ｓＧ’甫−９２４１ 第７図 １硫重力乙０ン裟ｒ瓜〕1A and 1B are a schematic plan sectional view and a schematic side sectional view of a conventional internal permanent magnet type print head, and FIG. 2 is a schematic side sectional view of a conventional external permanent magnet type print head. Figure 3a
, b is a schematic diagram of the print head showing the state of magnetic interference, the fourth
The figure is a magnetic interference characteristic diagram for a 24-pin print head, FIGS. 5a and 5b are a schematic plan sectional view and a schematic side sectional view of the print head in an embodiment of the present invention, and FIG. 6 is an embodiment of the present invention. FIG. 7, which is a drive circuit diagram of the print head in the example, is a diagram showing a method of controlling the main degaussing current. 13be. 1... Printing needle, 2... Bearing, 3...
・Housing, 4... Actuating body, 5... Leaf spring,
6...Spacer, 7...Support ring, 8...
... Substrate, 9... Magnetic pole column, 1°... Demagnetizing coil, 10 a... Sub-demagnetizing coil, 11...
...Converging magnetic pole column, 12...Permanent magnet, 13...River/yoke plate, 14...Tip column, 31...
Main degaussing coil. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3 (cL) CG Figure 4 16th ward in the morning Figure 5 Figure 6 oNou 32 ■[-σ0 ON ''-〇+-33 ON = 34-■-〇2
＼ l:1 j ■ j j j ON l sG'甫-9241 Figure 7 1 Sulfuric acid gravity

Claims (4)

【特許請求の範囲】[Claims] （１）印字針を有する複数の作動体と、前記複数の作動
体の一端にそれぞれ固着された板ばねと、前記板ばねの
一端を支持する支持リングと、前記支持リングを略円周
状に配設する基板と、前記支持リングの内側で前記基板
上に配され、かつ前記板ばねと対向する面を有する複数
の磁極柱および副消磁コイルと、前記基板の中心部に配
された収束磁極柱と、前記作動体に磁気力を及ぼすよう
に、前記収束磁極柱の一面に設けられた永久磁石と、前
記永久磁石の他面に設けられた継鉄柱とを具備し、前記
収束磁極柱と前記継鉄柱の少なくともいずれか一方に、
主消磁コイルを配した事を特徴とするドットプリンタ用
印字ヘッド。(1) A plurality of actuating bodies having printing needles, a leaf spring fixed to one end of the plurality of actuating bodies, a support ring supporting one end of the leaf spring, and a substantially circumferential shape of the support ring. a plurality of magnetic pole columns and sub-demagnetizing coils arranged on the substrate inside the support ring and having a surface facing the leaf spring; and a convergent magnetic pole arranged at the center of the substrate. a permanent magnet provided on one surface of the converging magnetic pole column so as to exert a magnetic force on the operating body, and a yoke column provided on the other surface of the permanent magnet, the converging magnetic pole column and At least one of the yoke columns,
A print head for dot printers featuring a main degaussing coil. （２）主消磁コイルと副消磁コイルを各々独立して通電
する事を特徴とする特許請求の範囲第１項記載のドット
プリンタ用印字ヘッド。(2) The print head for a dot printer according to claim 1, wherein the main demagnetizing coil and the sub-demagnetizing coil are each energized independently. （３）複数の副消磁コイルのうちいずれかを通電する時
のみ、主消磁コイルに通電する事を特徴とする特許請求
の範囲第１項記載のドットプリンタ用印字ヘッド。(3) The print head for a dot printer according to claim 1, wherein the main degaussing coil is energized only when any one of the plurality of sub-degaussing coils is energized. （４）主消磁コイルの電流を、駆動ピン数に略比例して
制御する事を特徴とする特許請求の範囲第１項記載のド
ットプリンタ用印字ヘッド。(4) The print head for a dot printer according to claim 1, wherein the current of the main degaussing coil is controlled approximately in proportion to the number of driving pins.