JPS5995163A - Printing head - Google Patents

Abstract

PURPOSE:To form a high speed head, in a printing head constituted of a spring charge system, by extending a fixing member for fixing a leaf spring to the vicinity of the central part of the available length of the leaf spring. CONSTITUTION:When a current is supplied to a coil 54 for a definite time toward a direction for negating the magnetic flux of a permanent magnet 56, an armature 51 is relieved from an attracted state to be rotated by the elastic force of a leaf spring 52 while the wire 55 secured to the leading end thereof is protruded to perform dot printing onto recording paper and, thereafter, the armature 51 is attracted to a core 53 by the magnetic flux of the permanent magnet 56 and the wire 55 is also returned to the stand-by position. Because an upper yoke 58 is extended to the P-point in the vicinity of the central part of the available length of the leaf spring 52, the deformation of the leaf spring to a B- direction generated by the movement due to shock generated when the wire 55 is collided with the recording paper and the inertia of the leaf spring is limited by the upper yoke 58. Therefore, secondary vibration generated by the leaf spring is suppressed and the wire is rapidly returned in a short contact time to be stopped after the collision with the recording paper.

Description

【発明の詳細な説明】 本発明はワイヤドツトプリンタの印字ヘッドに係り、更
に詳細にはばねに蓄えた弾性エネルギーによってワイヤ
を突出させるいわゆるスプリングチャージ方式の印字ヘ
ッドに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a print head for a wire dot printer, and more particularly to a so-called spring charge type print head in which a wire is protruded by elastic energy stored in a spring.

ドツトプリンタにおいては印字速度の高速化が図られて
おり、これに伴い印字ヘッドの応答性の向上が要請され
ている。従来のスプリングチャージ方式の印字ヘッドに
おいてはワイヤを駆動する板ばねに生ずる振動のため高
応答性が実現できないという欠点を有していた。第４図
には従来のスブリンチャージ方式印字ヘッドの構造を示
す。In dot printers, printing speeds are being increased, and as a result, there is a demand for improved responsiveness of print heads. Conventional spring-charge type print heads have the disadvantage that high responsiveness cannot be achieved due to vibrations generated in the leaf springs that drive the wires. FIG. 4 shows the structure of a conventional submerged charge type print head.

板ばね１０２に固着されたアーマチャ１０１は永久磁石
１０６の磁束によりコア１０３に吸引され、板ばね１０
２を偏倚された状態に保っている。永久磁石１０６の磁
界を打消す方向にコイル１０４に通電すると、アーマチ
ーア１０１は解放され、板ばね１０２の弾性力により回
転し、先端に固着されたワイヤ１０５が突出し、図示し
ていないインクリボンを介して記録紙を打撃してドツト
を形成する。第５図は、ワイヤ変位の時間変化を実線で
示す。同図に見られるように、ワイヤは記録紙に衝突後
復帰過程に入るまでに時間遅れを生ずる。これは板ばね
に発生する２次的な振動に起因する。第６図にはワイヤ
が記録紙に衝突した直後の板ばねの状態を模式的に示す
。ワイヤと記録紙との衝突によってうける衝撃によって
アーマチャに生ずる衝撃中心に関する回転モーメントや
、板ばねの慣性等によって、板ばねが図に示すように変
形し２次的な振動が生ずるためと考えられている。この
ために従来の構造においては、ワイヤの接触時間が長く
復帰速度が遅くなり、ワイヤの復帰静止に要する時間が
長くかかった。また高周波駆動時には特に板ばね等の運
動系の動作が不安定になりヘッドの高応答性が実現でき
ないという欠点を有していた。The armature 101 fixed to the leaf spring 102 is attracted to the core 103 by the magnetic flux of the permanent magnet 106, and the leaf spring 10
2 is kept biased. When the coil 104 is energized in a direction that cancels the magnetic field of the permanent magnet 106, the armature 101 is released and rotated by the elastic force of the leaf spring 102, and the wire 105 fixed to the tip protrudes, passing through an ink ribbon (not shown). The dots are formed by hitting the recording paper with the dots. FIG. 5 shows the change in wire displacement over time using a solid line. As seen in the figure, there is a time delay before the wire enters the recovery process after colliding with the recording paper. This is due to secondary vibrations generated in the leaf spring. FIG. 6 schematically shows the state of the leaf spring immediately after the wire collides with the recording paper. It is thought that this is because the leaf spring deforms as shown in the figure due to the rotational moment about the center of impact generated in the armature due to the impact caused by the collision between the wire and the recording paper, the inertia of the leaf spring, etc. as shown in the figure, and secondary vibrations occur. There is. For this reason, in the conventional structure, the contact time of the wire was long, and the return speed was slow, and the time required for the wire to return to rest was long. Furthermore, when driven at high frequencies, the operation of the motion system such as the leaf spring becomes unstable, making it impossible to achieve high responsiveness of the head.

これらの板ばねの２次的な振動をなくすため、２枚の板
ばねを十字形に配する構造Ｑ特公昭５６−４６９８９　
）も知られているが部品点数が増加し、ばねとアーマチ
ャとの固定部が複雑な構造となりコストアップや可動部
慣性質量の増加等の欠点を有していた。In order to eliminate the secondary vibrations of these leaf springs, a structure Q was developed in which two leaf springs were arranged in a cross shape.
) is also known, but it has disadvantages such as an increase in the number of parts, a complicated structure of the fixing part between the spring and the armature, an increase in cost, and an increase in the inertia mass of the movable part.

本発明はこれらの欠点を除いて高速ヘッドを実現するこ
とを目的とする。The present invention aims to eliminate these drawbacks and realize a high-speed head.

以下、図面を用いて本発明の詳細な説明する。Hereinafter, the present invention will be explained in detail using the drawings.

第１図は本発明の一実施例を示す印字ヘッドの断面図で
あり、スペーサ５７．下ヨーク５９は磁性体からなり、
永久磁石５６をはさみ込み磁路を形成する、アーマチャ
５１を固着した板ばね５２はスペーサ５７と磁性体から
なる上ヨーク５８にはさまれて固定される。アーマチャ
５１は永久磁石５６の磁束によりコア５３に吸引され、
板ばね５２を偏倚された状態に保っている。上ヨーク５
８は板ばね５２の固定端側から有効ばね長の中央部Ｐ点
付近まで伸びており、板ばね５８は矢印Ａ方向の動きに
は有効ばね長全長にわたってフリーであるが、矢印Ｂ方
向の動きはＰ点から固定部Ｑまで部分は、上ヨーク５８
によって規制される次に動作を説明する。永久磁石５６
の磁束を打消す方向にコイル５４に一定時間通電すると
、アーマチャ５１は吸引状態から解放され、板ばね５２
の弾性力により回転し、先端に固着されたワイヤ５５が
突出する。ワイヤ５５は図示していないインクリボン、
記録紙に衝突し、記録紙上にドツトを印字する。ドツト
印字後、アーマチャ５１は永久磁石５６の磁束によりコ
ア５３に吸引され、ワイヤ５５も待機位置に復帰する。FIG. 1 is a sectional view of a print head showing an embodiment of the present invention, and shows a spacer 57. The lower yoke 59 is made of a magnetic material,
A leaf spring 52 to which an armature 51 is fixed, which sandwiches a permanent magnet 56 to form a magnetic path, is sandwiched and fixed between a spacer 57 and an upper yoke 58 made of a magnetic material. The armature 51 is attracted to the core 53 by the magnetic flux of the permanent magnet 56,
The leaf spring 52 is kept biased. Upper yoke 5
8 extends from the fixed end side of the leaf spring 52 to near the center point P of the effective spring length, and the leaf spring 58 is free to move in the direction of arrow A over the entire effective spring length, but it is free to move in the direction of arrow B. The part from point P to fixed part Q is the upper yoke 58
The following describes the operations regulated by: Permanent magnet 56
When the coil 54 is energized for a certain period of time in the direction of canceling the magnetic flux, the armature 51 is released from the attracted state and the leaf spring 52
The wire 55 is rotated by the elastic force of the wire 55, and the wire 55 fixed to the tip protrudes. The wire 55 is an ink ribbon (not shown),
It collides with the recording paper and prints a dot on the recording paper. After dot printing, the armature 51 is attracted to the core 53 by the magnetic flux of the permanent magnet 56, and the wire 55 also returns to the standby position.

本実施例においては、上ヨーク５８が板ばね５２の有効
ばね長の中央部Ｐ点付近まで伸びているため、ワイヤ５
５が記録紙と衝突した際の衝撃によるモーメント及び板
ばね慣性によって生ずる板ばねのＢ方向への変形は上ヨ
ーク５８によって規制される。従って板ばねに生ずる２
次的な振動が抑えられ、ワイヤの変位の時間的変化は第
５図破線で示されるようになる。実線で示す従来例とく
らべて、ワイヤは記録紙との衝突後短い接触時間で速か
に復帰し静止する。さらに高周波駆動時にも安定して作
動する。In this embodiment, since the upper yoke 58 extends to near the point P at the center of the effective spring length of the leaf spring 52, the wire 58
The upper yoke 58 restricts the deformation of the leaf spring in the direction B, which is caused by the moment due to the impact and the inertia of the leaf spring when the sheet 5 collides with the recording paper. Therefore, 2 which occurs in the leaf spring
The subsequent vibrations are suppressed, and the temporal change in the displacement of the wire becomes as shown by the broken line in FIG. Compared to the conventional example shown by the solid line, the wire quickly recovers and comes to rest in a short contact time after colliding with the recording paper. Furthermore, it operates stably even when driven at high frequencies.

第２図は本発明の他の実施例を示す印字ヘッド断面図、
第３図はその駆動ユニ、トの分解図である。FIG. 2 is a sectional view of a print head showing another embodiment of the present invention;
FIG. 3 is an exploded view of the drive unit.

下ヨーク３にコア２を固定し上ヨーク４との間に永久磁
石１をはさみ込み固定軸１２を用いて固定する。板ばね
７の自白端部にはレバー８がプランジャ乙により一体に
かしめられる。レバー８は薄板からなり先端はワイヤ９
を巻込む形状で両者は抵抗溶接、ロー付等の手段で固定
される。板はね７は上ヨーク４と押え板１０の一部１０
ｃはレバー８の待機位置における度当りの機能も有し、
レバーとの衝突面にはゴム拐で形成されるストッパ１１
が取り付けられる。コア２に巻回されるコイル５の２つ
の電極端子１５．１６はばね性を有する。上述の駆動ユ
ニット３０は個別に組立調整後ヘッド本体に着脱可能で
ある。ヘッド本体への組込はヘッドフレーム１６のガイ
ド穴１３αに駆動ユニットの突起１０αを係合させて行
い、配線基板１７の対応するパターンと電極端子１５゜
１６を圧接して電気的接続が行われる。ヘッドフレーム
１３と駆動ユニット間にはゴムシート１４を介在させて
各駆動ユニット間の長さのバラツキによる組立上の不具
合を解消するとともに騒音の発生を防止する。次に裏ブ
タ２５を固定ばね２６により弾性的に固定することによ
りヘッドが組立てられる。A core 2 is fixed to a lower yoke 3, a permanent magnet 1 is inserted between it and an upper yoke 4, and fixed using a fixed shaft 12. A lever 8 is swaged together with the free end of the leaf spring 7 by a plunger B. The lever 8 is made of a thin plate and has a wire 9 at the tip.
The two are fixed by resistance welding, brazing, etc. The plate spring 7 is a part 10 of the upper yoke 4 and the presser plate 10.
c also has the function of perforating the lever 8 in its standby position;
A stopper 11 made of rubber is provided on the collision surface with the lever.
can be installed. The two electrode terminals 15 and 16 of the coil 5 wound around the core 2 have spring properties. The above-mentioned drive unit 30 can be individually attached to and detached from the head body after assembly and adjustment. Incorporation into the head body is performed by engaging the protrusion 10α of the drive unit with the guide hole 13α of the head frame 16, and electrical connection is made by pressing the corresponding pattern of the wiring board 17 and the electrode terminals 15° 16. . A rubber sheet 14 is interposed between the head frame 13 and the drive unit to eliminate assembly problems caused by length variations between the drive units and to prevent noise from occurring. Next, the head is assembled by elastically fixing the back cover 25 with the fixing spring 26.

本実施例では、板ばね７はワイヤ９とほぼ平行に配置さ
れており、この点で先の実施例と異なる。押え板１０の
板ばね固定部１０ｄは板ばね７の有効ばね長の中央部Ｒ
点付近まで伸びており、板ばね７は矢印Ｏ方向の動きは
有効ばね長全長にわたってフリーであるが、矢印り方向
の動きはＲ点から固定端側の部分は押え板の板はね固定
部１０ｄにより規制される。待機状態では永久磁石１の
磁束によりプランジャ６はコア２に吸着され、板はね７
は矢印Ｃ方向に偏倚保持される。コイル５に永久磁石１
の磁界を打消す方向に一定時間通電するとプランジャ６
が吸引状態から解放され、板はね７の弾性力によりレバ
ー８が回転してワイヤ９が突出し、印字が行なわれる。In this embodiment, the leaf spring 7 is arranged substantially parallel to the wire 9, which is different from the previous embodiment. The leaf spring fixing portion 10d of the holding plate 10 is located at the center R of the effective spring length of the leaf spring 7.
The leaf spring 7 is free to move in the direction of the arrow O over the entire effective spring length, but the part of the leaf spring 7 in the direction of the arrow from the fixed end side from the point R is due to the leaf spring fixing part of the presser plate. 10d. In the standby state, the plunger 6 is attracted to the core 2 by the magnetic flux of the permanent magnet 1, and the plate spring 7
is held biased in the direction of arrow C. Permanent magnet 1 in coil 5
When the current is applied for a certain period of time in the direction of canceling the magnetic field of the plunger 6
is released from the suction state, the lever 8 is rotated by the elastic force of the plate spring 7, the wire 9 is projected, and printing is performed.

印字後プランジャ６はコア２に吸引され待機状態に復帰
する。After printing, the plunger 6 is attracted by the core 2 and returns to the standby state.

板はね７の有効ばね長の中央部Ｒ点付近まで、板はね固
定部１ｏｄが伸びているため、先の実施例と同様に、印
字後の板ばねの２次振動が防止され、ワイヤは速やかに
待機位置に復帰する。Since the plate spring fixing part 1od extends to near point R of the effective spring length of the plate spring 7, secondary vibration of the plate spring after printing is prevented as in the previous embodiment, and the wire quickly returns to the standby position.

以上述べてきたように本発明によれば、ｆｊＮ単な構造
で応答性の高い印字ヘッドが実現できる。更に可動体の
有する運動エネルギが有効にワイヤに伝えられ高い印字
濃度か得られるという効果も有する。As described above, according to the present invention, a print head with high responsiveness can be realized with a simple fjN structure. Furthermore, the kinetic energy of the movable body is effectively transmitted to the wire, resulting in a high print density.

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

第１図は本発明の一実施例を示す印字ヘッドの断面図、
第２図は他の実施例を示す印字ヘッドの断面図、第６図
はその駆動ユニ、トの分解図、第４図は従来例を示す印
字ヘッドの断可図、第５図はワイヤ変位の時間変化を示
す図、第６図は従来例の印字の際の模式図である。 １．５６・・・・・・永久磁石 ７．５２・・・・・・板ばね ９．５５・・・・・・ワイヤ １０・・・・・・・・・・・・押え板 取　　上 出願人　エプソン株式会イλ 第２図FIG. 1 is a sectional view of a print head showing an embodiment of the present invention;
Fig. 2 is a sectional view of the print head showing another embodiment, Fig. 6 is an exploded view of its drive unit, Fig. 4 is a cutaway view of the print head showing a conventional example, and Fig. 5 is a wire displacement diagram. FIG. 6 is a schematic diagram showing a conventional printing process. 1.56... Permanent magnet 7.52... Leaf spring 9.55... Wire 10... Holder board upper applicant Epson Corporation Iλ Figure 2

Claims (1)

【特許請求の範囲】[Claims] 永久磁石により板ばねに固着した磁性体を吸引して前記
板ばねを偏倚し、消磁コイルの通電により前記永久磁石
の磁界を打消して前記吸ｉＪ＋状態を解放して前記板ば
ねに連結されたワイヤを突出させるバネチャージ方式の
印字ヘッドにおいて、前記板ばねを固定する固定部材は
、前記板ばねの有効ばね長の中央部近辺まで前記吸引方
向と反対の部分が延長されていることを特徴とする印字
ヘッド。A permanent magnet attracts the magnetic body fixed to the leaf spring to bias the leaf spring, and energization of a degaussing coil cancels the magnetic field of the permanent magnet to release the attracted iJ+ state and connect the leaf spring. In the spring-charged print head in which the wire protrudes, the fixing member for fixing the leaf spring has a portion opposite to the suction direction extending to a vicinity of the center of the effective spring length of the leaf spring. print head.