JPH0569570A - Thick film type thermal head - Google Patents
Thick film type thermal headInfo
- Publication number
- JPH0569570A JPH0569570A JP8943091A JP8943091A JPH0569570A JP H0569570 A JPH0569570 A JP H0569570A JP 8943091 A JP8943091 A JP 8943091A JP 8943091 A JP8943091 A JP 8943091A JP H0569570 A JPH0569570 A JP H0569570A
- Authority
- JP
- Japan
- Prior art keywords
- scanning direction
- heating resistor
- thermal head
- sub
- common electrode
- 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.)
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Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、個別対向型の厚膜型サ
ーマルヘッドに係り、特に昇華式プリンタ等の記録装置
の印字品質を向上させるための新規な構造を備えた厚膜
型サーマルヘッドに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an individually opposed thick film thermal head, and more particularly to a thick film thermal head having a novel structure for improving the printing quality of a recording device such as a sublimation printer. Regarding
【0002】[0002]
【従来の技術】感熱方式プリンタやファクシミリ等の記
録装置の記録手段に用いられる記録ヘッドとしては、製
造の容易さから所謂厚膜型サーマルヘッドと呼ばれる記
録ヘッドが広く採用れている。感熱方式記録装置の一形
式として、インクドナーフィルムのインクを加熱昇華さ
せて記録媒体に画像や文字を形成する昇華式記録装置が
知られている。2. Description of the Related Art As a recording head used for recording means of a recording device such as a thermal printer or a facsimile, a recording head so-called a thick film type thermal head is widely adopted because of its ease of manufacture. As one type of thermal recording apparatus, there is known a sublimation recording apparatus that heats and sublimates ink in an ink donor film to form an image or a character on a recording medium.
【0003】図5は厚膜型サーマルヘッドを印字ヘッド
とした昇華式記録装置の要部説明図であって、1はセラ
ミックス等の絶縁材料からなる基板、2は共通電極、3
は個別電極、4は発熱抵抗体、6は発熱抵抗体と共通電
極および個別電極を覆って形成された保護層であるオー
バーグレーズ層で、これらの構成層により厚膜型サーマ
ルヘッド10が構成される。また、7はプラテン、8は
記録媒体、80はインクドナーフィルムである。同図に
おいて、記録時には記録媒体8とインクドナーフィルム
80とが厚膜型サーマルヘッド10とプラテン7との間
に矢印Pで示した押圧力で挟持押圧され、サーマルヘッ
ドの発熱によりインクドナーフィルム80が加熱される
ことによって昇華した染料が記録媒体(昇華型記録紙)
8に移転さて記録が行なわれる。サーマルヘッドはその
電極の配置構造から分類して、共通電極と個別電極とが
副走査方向に対向配置された個別対向型サーマルヘッド
と、共通電極と個別電極とが主走査方向に櫛歯状に配列
された交互リード型サーマルヘッドとに大別される。FIG. 5 is an explanatory view of a main part of a sublimation type recording apparatus using a thick film type thermal head as a print head. Reference numeral 1 is a substrate made of an insulating material such as ceramics, 2 is a common electrode, and 3 is a common electrode.
Is an individual electrode, 4 is a heating resistor, 6 is an overglaze layer which is a protective layer formed to cover the heating resistor, the common electrode and the individual electrode, and the thick film type thermal head 10 is constituted by these constituent layers. It Further, 7 is a platen, 8 is a recording medium, and 80 is an ink donor film. In the drawing, at the time of recording, the recording medium 8 and the ink donor film 80 are nipped and pressed between the thick film type thermal head 10 and the platen 7 with the pressing force shown by the arrow P, and the ink donor film 80 is generated by the heat generation of the thermal head. The dye sublimated by heating the recording medium (sublimation type recording paper)
Moved to 8 for recording. The thermal head is classified according to the arrangement structure of its electrodes. The individual facing thermal head in which the common electrode and the individual electrode are arranged to face each other in the sub-scanning direction, and the common electrode and the individual electrode are comb-shaped in the main scanning direction. It is roughly classified into an arrayed alternating read type thermal head.
【0004】図6は従来技術による個別対向型の厚膜型
サーマルヘッドの構造を説明する要部平面図であって、
010は厚膜型サーマルヘッド、01はセラミック基
板、02は共通電極、03は個別電極、04は発熱抵抗
体、06は保護層であるオーバーグレーズ層である。こ
の種の厚膜型サーマルヘッドは、電極層形成材料や発熱
体となる抵抗層形成材料をペースト状として印刷し、塗
布・焼成して所望の構成層を得るリフトオフ法により製
作される。FIG. 6 is a plan view of an essential part for explaining the structure of an individually opposed type thick film type thermal head according to the prior art.
Reference numeral 010 is a thick film type thermal head, 01 is a ceramic substrate, 02 is a common electrode, 03 is an individual electrode, 04 is a heating resistor, and 06 is an overglaze layer which is a protective layer. This type of thick film type thermal head is manufactured by a lift-off method in which an electrode layer forming material and a resistance layer forming material serving as a heating element are printed in a paste form, applied and fired to obtain a desired constituent layer.
【0005】図7は図6に示した厚膜型サーマルヘッド
の断面図で、(a)は図6のA−A線に沿った副走査方
向断面を、(b)は図6のB−B線に沿った主走査方向
断面を示す。同図(a)(b)に示されたように、発熱
抵抗体04は共通電極02と個別電極03を形成した上
にこれら両電極の上部に橋絡して形成される。したがっ
て、この種のリフトオフ法により製作した個別対向型の
厚膜型サーマルヘッドは、発熱抵抗体04の副走査方向
の断面形状が記録媒体方向に凸であるために、オーバー
グレーズ層06も凸形状をなしている。なお、上記従来
の厚膜型サーマルヘッドを開示したものとしては、特開
平1−123756号公報,特開昭64−44762号
公報を挙げることができる。上記各公報に開示の厚膜型
サーマルヘッドは、発熱抵抗体の形状を主および副走査
の各方向の断面形状を矩形とすることによって発熱抵抗
体の発熱分布を均一とし、発熱抵抗体の平面形状の再現
性すなわちドット再現性を向上させたものである。FIG. 7 is a sectional view of the thick film type thermal head shown in FIG. 6. FIG. 7A is a sectional view in the sub-scanning direction along the line AA of FIG. 6, and FIG. 7B is a sectional view of FIG. A cross section in the main scanning direction along line B is shown. As shown in FIGS. 3A and 3B, the heating resistor 04 is formed by forming a common electrode 02 and an individual electrode 03, and bridging above these electrodes. Therefore, in the individually opposed type thick film type thermal head manufactured by the lift-off method of this kind, since the sectional shape of the heating resistor 04 in the sub-scanning direction is convex in the recording medium direction, the overglaze layer 06 is also convex. Is playing. As a disclosure of the conventional thick film type thermal head, there are JP-A-1-123756 and JP-A-64-44762. The thick film type thermal head disclosed in each of the above publications makes the heating resistor uniform in heat generation by making the heating resistor have a rectangular cross-sectional shape in each of the main and sub-scanning directions, and the heating resistor has a flat surface. The shape reproducibility, that is, the dot reproducibility is improved.
【0006】[0006]
【発明が解決しようとする課題】従来のこの種の厚膜型
サーマルヘッドにおいては、共通電極02と個別電極0
3の間隔Dと発熱抵抗体04の副走査方向幅dとの寸法
に大きな差が無いため、共通電極02と個別電極03を
介して発熱抵抗体04に通電すると、発熱抵抗体04は
そのエッジまでの全長に亘って加熱される。そのため、
オーバーグレーズ層06もそのエッジまでの凸部全体が
加熱されることになる。このサーマルヘッドの昇華式記
録装置に搭載して昇華式記録媒体に印字等の記録を行な
うと、発熱抵抗体上のオーバーグレーズ層の凸形状部分
全体が、発熱抵抗体の発熱と共に記録媒体8の表面を加
熱し、インクドナーフィルムの染料を昇華させる温度に
達する中央部分にインクの染料が移転されて記録がなさ
れることになる。In the conventional thick film type thermal head of this type, the common electrode 02 and the individual electrode 0 are not used.
Since there is no great difference in the dimension between the distance D of 3 and the width d of the heating resistor 04 in the sub-scanning direction, when the heating resistor 04 is energized via the common electrode 02 and the individual electrode 03, the heating resistor 04 has its edge. Is heated over its entire length. for that reason,
In the overglaze layer 06 as well, the entire convex portion up to the edge thereof is heated. When the sublimation recording device of this thermal head is mounted and recording such as printing is performed on the sublimation recording medium, the entire convex portion of the overglaze layer on the heating resistor is heated by the heating resistor and the recording medium 8 is heated. Recording is performed by transferring the dye of the ink to the central portion where the surface is heated and reaches the temperature at which the dye of the ink donor film is sublimated.
【0007】図8は個別対向型の厚膜型サーマルヘッド
を用いた昇華型記録媒体の記録状態を説明する模式図で
あって、従来は、例えば10dot/mmのサーマルヘ
ッドにおいて、発熱抵抗体の主走査幅を70μm、また
電極間幅140μmに対し、発熱抵抗体の副走査幅を従
来は170μm程度としている。この場合、発熱抵抗体
突起(オーバーグレーズ層の突起)の圧痕そのものは該
突起のエッジの形状を転写した凹11となり、その結果
圧痕の周りは凸になる。また、10dot/mmで上記
の発熱抵抗体サイズの場合、紙送り0.1mm/lin
eであるから、70μmの凹11の重なり代が生じ、そ
の重なり代で記録媒体表面の凹凸が激しくなる。上記発
熱抵抗体(オーバーグレーズ層)のエッジの凸形状で記
録媒体に圧痕がつくのは、発熱抵抗体副走査方向端部の
エッジまで、したがってオーバーグレーズ層のエッジま
で熱が伝わり、昇華式記録媒体表面の上記エッジが当た
る領域はすべて変形しやすくなるためである。FIG. 8 is a schematic diagram for explaining a recording state of a sublimation type recording medium using an individually opposed type thick film type thermal head. Conventionally, in a thermal head of 10 dots / mm, for example, a heating resistor is used. While the main scanning width is 70 μm and the inter-electrode width is 140 μm, the sub-scanning width of the heating resistor is conventionally about 170 μm. In this case, the indentation itself of the heating resistor projection (projection of the overglaze layer) becomes the recess 11 in which the shape of the edge of the projection is transferred, and as a result, the circumference of the indentation becomes convex. When the above heating resistor size is 10 dot / mm, the paper feed is 0.1 mm / lin.
Since it is e, an overlapping margin of the recess 11 of 70 μm occurs, and the unevenness of the surface of the recording medium becomes severe due to the overlapping margin. The indentation on the recording medium due to the convex shape of the edge of the heating resistor (overglaze layer) causes the heat to reach the edge of the heating resistor in the sub-scanning direction, and thus to the edge of the overglaze layer, and the sublimation recording. This is because all the regions of the medium surface where the above edge hits are easily deformed.
【0008】すなわち、昇華式記録用の記録媒体8の表
面は熱により変形しやすい状態となるものであるため、
上記のサーマルヘッドで印字すると、同図(a)に示す
ように、記録媒体8の表面には厚膜型サーマルヘッドの
発熱抵抗体4のエッジ,したがってこの発熱抵抗体4の
エッジとほぼ同一サイズのオーバーグレーズ層6のエッ
ジによる凸形状がそのまま凹部11として転写される。
そして、上記凹部11の中央部に昇華温度に達して昇華
したインクの染料9が移転する。染料9が移転した記録
媒体部分は、図示のごとく膨潤して僅かに凸状となる。
そして、次の記録動作で(b)に示したように先の記録
で形成された凹部11にさらに凹部11が重畳し、これ
が(c)に示した如く次々に凹部11と膨潤部が形成さ
れる。このため、記録媒体8の表面に凹凸が激しく発生
してドット再現性が損なわれ、その結果画質の劣化を招
くという問題がある。なお、昇華式記録に関しては、例
えば、「テレビジョン学会技術報告」(vol.14,
no.6,pp.1〜6,”昇華型熱転写印刷における
高画質化”1990を挙げることができる。That is, since the surface of the recording medium 8 for sublimation recording is easily deformed by heat,
When printing is performed with the above-mentioned thermal head, as shown in FIG. 6A, the edge of the heating resistor 4 of the thick film type thermal head, and therefore the edge of the heating resistor 4, is approximately the same size on the surface of the recording medium 8. The convex shape due to the edge of the overglaze layer 6 is directly transferred as the concave portion 11.
Then, the dye 9 of the ink sublimated by reaching the sublimation temperature is transferred to the central portion of the recess 11. The recording medium portion to which the dye 9 has transferred swells and becomes slightly convex as shown.
Then, in the next recording operation, the recess 11 is further overlapped with the recess 11 formed in the previous recording as shown in (b), and this forms the recess 11 and the swollen portion one after another as shown in (c). It For this reason, there is a problem in that the surface of the recording medium 8 is severely uneven and dot reproducibility is impaired, resulting in deterioration of image quality. Regarding the sublimation recording, for example, “Technical Report of the Television Society” (vol. 14,
no. 6, pp. 1 to 6, "improvement of image quality in sublimation type thermal transfer printing" 1990.
【0009】前記のような問題を解消するものとして、
リフトオフ法による個別対向型の厚膜型サーマルヘッド
において発熱抵抗体副走査方向の幅を電極間隔の幅の2
倍以上として上記抵抗体の副走査方向端部のエッジ(す
なわち、オーバーグレーズ層の副走査方向エッジ)の影
響を受けないようにし、ドット再現性の良さを損なうこ
となく、昇華式記録装置で記録した記録媒体表面の凹凸
をなくし、画質を向上させることが提案されている。個
別対向リフトオフ法で上記の発熱抵抗体を作成する際
に、フォトレジストの露光,現像により形成するフォト
レジストパターンに、形成すべき発熱抵抗体形状の開口
部を設けることが行なわれるが、近接して形成すべき発
熱抵抗体を分離する部分のフォトレジスト(以下、フォ
トレジスト柱という)は副走査方向幅が長くなるほど倒
れたり折れたりし易くなる。これを無くすために、フォ
トレジストレジスト柱の主走査方向幅を大きくすると、
発熱抵抗体の主走査方向幅が小さくなって、記録ドット
の主走査方向の繋がりが悪化するという問題が生じる。To solve the above problems,
In the individually opposed type thick film thermal head by the lift-off method, the width of the heating resistor in the sub-scanning direction is equal to the width of the electrode interval of 2
As a double or more, it is not affected by the edge of the resistor in the sub-scanning direction end (that is, the edge of the overglaze layer in the sub-scanning direction), and recording is performed by the sublimation recording device without impairing the dot reproducibility. It has been proposed to improve the image quality by eliminating the irregularities on the surface of the recording medium. When the above heating resistor is formed by the individual counter lift-off method, the photoresist pattern formed by exposure and development of the photoresist is provided with an opening in the shape of the heating resistor to be formed, but it is close to it. The photoresist (hereinafter, referred to as a photoresist pillar) in a portion for separating the heating resistor to be formed as described above is more likely to fall or break as the width in the sub-scanning direction becomes longer. To eliminate this, if the width of the photoresist column in the main scanning direction is increased,
The width of the heating resistor in the main scanning direction becomes smaller, which causes a problem that the connection of the recording dots in the main scanning direction deteriorates.
【0010】図9は発熱抵抗体形成工程における発熱抵
抗体形成用フォトレジストパターンの説明図であって、
(a)は従来のサーマルヘッド製作用のフォトレジスト
パターン、(b)は本発明によるサーマルヘッド製作用
のフォトレジストパターンの一実施例を示す。同図
(a)において、Fは露光により硬化したフォトレジス
ト、FR1,FR2, FR3, ・・・・は発熱抵抗体形成用開
口部、C1,C2,C3,・・・・は隣接する発熱抵抗体形成
用開口部FR1,FR2, FR3, ・・・・間を分離するフォ
トレジスト柱である。このフォトレジスト柱C1,C2,C
3,・・・・は、その副走査方向が長い,すなわち上記従
来技術における抵抗体副走査方向の幅を電極間隔の幅の
2倍以上としたサーマルヘッドの抵抗体を形成するため
に抵抗体ペーストを当該開口部FR1,FR2, FR3, ・・
・・に充填する工程において、隣接する開口部FR1,F
R2, FR3, ・・・・側に倒れ込みが生じたり、折れが生
じて、発熱抵抗体の形状を歪めたり、隣接する抵抗体間
の分離がなされなかったりする。そのために、製造歩留
りは低下し、図6に示した従来の通常サイズの抵抗体を
備えたサーマルヘッドに比べて歩留りが40パーセント
近く低下する。FIG. 9 is an illustration of a photoresist pattern for forming a heating resistor in the heating resistor forming step,
1A shows an example of a conventional photoresist pattern for producing a thermal head, and FIG. 1B shows an example of a photoresist pattern for producing a thermal head according to the present invention. In FIG. 4A, F is a photoresist hardened by exposure, F R1, F R2, F R3, ... Are openings for heating resistor formation, C 1, C 2, C 3 ,. Is a photoresist pillar for separating the adjacent heating resistor forming openings F R1, F R2, F R3, ... This photoresist pillar C 1, C 2, C
3, ... are resistors for forming a resistor of the thermal head whose length in the sub-scanning direction is long, that is, the width in the sub-scanning direction of the resistor in the above-mentioned prior art is twice or more the width of the electrode interval. Paste the openings F R1, F R2, F R3, ...
..Adjacent openings F R1, F in the filling process
R2, F R3, ... The side of the heating resistor may be collapsed or bent to distort the shape of the heating resistor or the adjacent resistors may not be separated. As a result, the manufacturing yield is reduced, and the yield is reduced by nearly 40% as compared with the thermal head including the conventional normal size resistor shown in FIG.
【0011】また、抵抗体ペーストの主走査方向のサイ
ズに比べて副走査方向が長いと、該抵抗体ペーストの焼
成時にその副走査方向の収縮が大きくなって、焼成後の
発熱抵抗体に大きな内部歪みが発生し、ステップ スト
レス テスト強度(Stepp Stress Tes
t:以下SST強度という)が低下するという問題があ
る。ちなみに、下記に説明する図4の(a)に示した抵
抗体の副走査方向幅を電極間隔幅の2倍とした巨大抵抗
体(主走査方向×副走査方向:70μm×350μm)
においては、SST強度は同図(b)に示した通常のサ
イズの抵抗体(同70μm×170μm)よりも25パ
ーセント以上の低下がみられる。If the sub-scanning direction is longer than the size of the resistor paste in the main-scanning direction, the shrinkage of the resistor paste in the sub-scanning direction becomes large at the time of firing, which is large in the heating resistor after firing. Internal strain occurs and the step stress test strength (Step Stress Tests
There is a problem that (t: hereinafter referred to as SST strength) decreases. Incidentally, a giant resistor (main scanning direction × sub scanning direction: 70 μm × 350 μm) in which the width in the sub scanning direction of the resistor shown in FIG. 4A described below is twice the electrode spacing width
In Fig. 5, the SST intensity is 25% or more lower than that of the normal-sized resistor (70 µm x 170 µm) shown in Fig. 7B.
【0012】図4は、(a)が従来サイズ、(b)が上
記巨大サイズ、(c)が本発明の一実施例におけるSS
T強度測定結果を示す説明図で、テスト時間(SSTt
ime)を20sec,印加パルス幅(pulse w
idth)を6msec,パルス周期を20msec,
ドロップ電圧(drop voltage)を0.5V
として、横軸に印加電力(W ワット)を、縦軸に抵抗
偏差(resistance variance パー
セント)をとって示している。本発明の目的は、個別対
向型リフトオフサーマルヘッドを構成する発熱抵抗体副
走査幅を電極間隔の例えば2倍以上として該抵抗体副走
査方向エッジによる記録媒体上の圧痕発生を解消しよう
とするサーマルヘッドを精度よく製造可能とすると共
に、発熱抵抗体の内部歪みを低減させて、画像品質を向
上させたサーマルヘッドを提供することを目的とする。In FIG. 4, (a) is a conventional size, (b) is the huge size, and (c) is an SS according to an embodiment of the present invention.
It is explanatory drawing which shows the T strength measurement result, and shows test time (SSTt
20 sec, the applied pulse width (pulse w)
idth) 6 msec, pulse period 20 msec,
Drop voltage (drop voltage) 0.5V
The horizontal axis represents applied power (W watt) and the vertical axis represents resistance deviation (percentage of resistance variance). It is an object of the present invention to set a sub-scanning width of a heating resistor forming an individually opposed lift-off thermal head to, for example, two times or more the electrode interval, and to eliminate an indentation on a recording medium due to an edge in the sub-scanning direction of the resistor. An object of the present invention is to provide a thermal head capable of manufacturing a head with high accuracy and reducing internal distortion of a heating resistor to improve image quality.
【0013】[0013]
【課題を解決するための手段】上記目的を達成するため
に、本発明は、発熱抵抗体の副走査幅が電極間隔の2倍
以上としたサーマルヘッドの上記発熱抵抗体の共通電極
側および個別電極側のそれぞれの上部に主走査方向のス
リットを設け、このスリットによって副走査方向に分離
された副走査方向端部側の発熱抵抗体をダミー抵抗体と
したことを特徴とする。すなわち、本発明は、共通電極
と、共通電極に対して互いに独立して対向し主走査方向
に配置される複数の個別電極と、上記共通電極と個別電
極のそれぞれに副走査方向に橋絡する発熱抵抗体と、上
記共通電極,個別電極および発熱抵抗体を覆う保護層と
を有する厚膜型サーマルヘッドにおいて、前記共通電極
と個別電極のそれぞれの上に前記発熱抵抗体の副走査方
向端部に隣接してダミー抵抗体を設けたことを特徴とす
る。In order to achieve the above object, the present invention provides a thermal head in which the sub-scanning width of the heating resistor is twice or more the electrode interval, and the common electrode side and the individual of the heating resistor. A slit in the main scanning direction is provided on each of the upper portions on the electrode side, and the heating resistor on the end side in the sub scanning direction separated by the slit in the sub scanning direction is a dummy resistor. That is, according to the present invention, a common electrode, a plurality of individual electrodes that face the common electrode independently of each other and are arranged in the main scanning direction, and bridge the common electrode and the individual electrode in the sub-scanning direction. In a thick film type thermal head having a heating resistor and a protective layer covering the common electrode, the individual electrode and the heating resistor, an end portion of the heating resistor in the sub-scanning direction is provided on each of the common electrode and the individual electrode. Is characterized in that a dummy resistor is provided adjacent to.
【0014】[0014]
【作用】共通電極と個別電極のそれぞれの上に前記発熱
抵抗体の副走査方向端部に隣接してダミー抵抗体を設け
たことにより、発熱抵抗体の副走査方向幅を電極間隔の
2倍以上とした昇華型記録装置用のサーマルヘッドのよ
うに、抵抗体の副走査方向幅が主走査方向幅より相当大
きいサイズとしたサーマルヘッドと同等の効果を有する
サーマルヘッドをフォトリソグラフ技法で作成する際の
フォトレジスト柱の倒れや折れを無くし、かつ発熱抵抗
体の内部歪みを低減させて精度のよい発熱抵抗体を形成
し、記録品質を向上させると共に、歩留りの大きいサー
マルヘッドを得ることができる。また、発熱体として機
能する発熱抵抗体のSST強度を、該抵抗体の副走査方
向幅と電極間隔幅の寸法関係が2倍未満である従来形式
のサーマルヘッドと同等のものとすることが可能とな
る。The dummy resistor is provided on each of the common electrode and the individual electrode so as to be adjacent to the end of the heating resistor in the sub-scanning direction, so that the width of the heating resistor in the sub-scanning direction is twice the electrode interval. Like the thermal head for the sublimation type recording apparatus described above, a thermal head having the same effect as that of the thermal head in which the width of the resistor in the sub-scanning direction is considerably larger than the width in the main scanning direction is produced by the photolithography technique. In this case, it is possible to prevent the photoresist column from collapsing or bending, reduce the internal strain of the heating resistor to form an accurate heating resistor, improve recording quality, and obtain a thermal head with a high yield. .. Further, the SST strength of the heating resistor functioning as a heating element can be made equal to that of a conventional type thermal head in which the dimensional relationship between the width of the resistor in the sub-scanning direction and the electrode interval width is less than twice. Becomes
【0015】[0015]
【実施例】以下、本発明の実施例につき、図面を参照し
て詳細に説明する。図1は本発明による厚膜型サーマル
ヘッドの一実施例を説明する要部平面図であって、1は
セラミック基板、2は共通電極、3は個別電極、4は発
熱抵抗体、5a,5bはダミー抵抗体、6はオーバーグ
レーズ層である。また、図2は図1に示した厚膜型サー
マルヘッドの断面図で、(a)は図1のA−A線に沿っ
た副走査方向断面図、(b)は図1のB−B線に沿った
断面図である。図1,図2において、このサーマルヘッ
ドは、セラミック基板1の上面に共通電極2と複数の個
別電極3とを形成し、それぞれ間隔D(電極間隔幅)で
対向する共通電極2と個別電極3との上に橋絡して配置
した発熱抵抗体4を有し、さらに共通電極2と個別電極
3のそれぞれの上に、上記発熱抵抗体4の副走査方向端
部とスリットを介して配置されたダミー抵抗体5a,5
bを備えている。そして、ダミー抵抗体5a,5bを含
む副走査方向の幅d’は電極間隔Dの2倍以上である。
発熱抵抗体4の電極対向端からそれぞれ所定距離だけ副
走査方向に離れた位置に、主走査方向に沿ったスリット
を有して、このスリットで分離された発熱抵抗体部分
を、それぞれダミー抵抗体5a,5bとしている。この
ダミー抵抗体5a,5bは発熱抵抗体4から熱的に分離
されて、副走査方向幅dの発熱抵抗体4が発熱部を形成
し、インクドナーフィルムの昇華に寄与する。Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a plan view of an essential part for explaining an embodiment of a thick film type thermal head according to the present invention, in which 1 is a ceramic substrate, 2 is a common electrode, 3 is an individual electrode, 4 is a heating resistor, 5a and 5b. Is a dummy resistor, and 6 is an overglaze layer. 2 is a sectional view of the thick film type thermal head shown in FIG. 1, (a) is a sectional view in the sub-scanning direction along the line AA of FIG. 1, and (b) is a sectional view taken along the line BB of FIG. It is sectional drawing which followed the line. 1 and 2, the thermal head has a common electrode 2 and a plurality of individual electrodes 3 formed on the upper surface of a ceramic substrate 1, and the common electrode 2 and the individual electrodes 3 are opposed to each other at an interval D (electrode interval width). And a heating resistor 4 arranged in a bridging manner above the heating resistor 4, and further disposed on each of the common electrode 2 and the individual electrode 3 via the end of the heating resistor 4 in the sub-scanning direction and a slit. Dummy resistors 5a, 5
b. The width d'in the sub-scanning direction including the dummy resistors 5a and 5b is at least twice the electrode spacing D.
The heating resistor 4 has slits along the main scanning direction at positions separated from the electrodes facing each other by a predetermined distance in the sub-scanning direction, and the heating resistor portions separated by the slits are respectively dummy resistors. 5a and 5b. The dummy resistors 5a and 5b are thermally separated from the heating resistor 4, and the heating resistor 4 having a width d in the sub-scanning direction forms a heating portion, which contributes to sublimation of the ink donor film.
【0016】図3は図1,図2に示した本実施例のサー
マルヘッドで記録した記録媒体の(a)表面図と(b)
断面図である。具体的な寸法例として、上記電極間幅D
が140μmのサーマルヘッドにおいて発熱抵抗体4の
副走査方向の幅dを170μm、発熱抵抗体4の副走査
方向に幅30μmのスリットを介して副走査方向幅が2
5μmのダミー抵抗体5a,5bを設けて、発熱抵抗体
4とダミー抵抗体5a,5bの副走査方向の合計幅d’
を電極間幅Dの2倍(280μm)としたもので記録し
た。同図に示すように、副走査方向の発熱抵抗体4のエ
ッジ(オーバーグレーズ層6のエッジ)による圧痕
(凹)が見られず、昇華染料移転部9が若干膨潤した状
態となる。そのため、記録媒体の表面状態は従来技術の
サーマルヘッドによるものに比較して極めて平滑とな
り、良好な画質を提供できる。また、オーバーグレーズ
層6を、発熱抵抗体4およびダミー抵抗体の上面におい
て平坦化することで、画質向上効果をさらに上げること
ができる。このオーバーグレーズ層6の平坦化は、オー
バーグレーズ層を形成する材料の粘度,ぬれ性などの選
択、オーバーグレーズ層材料を多層印刷して発熱抵抗体
およびダミー抵抗体の厚さ以上に形成した後、ラッピン
グ処理で研磨して平坦化する方法を採ることができる。
なお、上記数値はあくまで一例であり、本発明は発熱に
寄与する抵抗体の副走査方向端に、該発熱に寄与する抵
抗体と一定の距離において分離したダミー抵抗体を設け
ることで、従来技術における記録媒体の圧痕の発生を無
くし、画像品質を向上できる。FIG. 3 is a (a) surface view of a recording medium recorded by the thermal head of the present embodiment shown in FIGS. 1 and 2 and (b).
FIG. As a specific dimension example, the inter-electrode width D
Is 140 μm, the width d of the heating resistor 4 in the sub-scanning direction is 170 μm, and the width of the heating resistor 4 in the sub-scanning direction is 2 μm through the slit of 30 μm in the sub-scanning direction.
By providing the dummy resistors 5a and 5b of 5 μm, the total width d ′ of the heating resistor 4 and the dummy resistors 5a and 5b in the sub-scanning direction.
Was recorded twice as wide as the interelectrode width D (280 μm). As shown in the figure, no indentation (concave) due to the edge of the heating resistor 4 (edge of the overglaze layer 6) in the sub-scanning direction is seen, and the sublimation dye transfer portion 9 is in a slightly swollen state. Therefore, the surface condition of the recording medium becomes much smoother than that of the conventional thermal head, and good image quality can be provided. Further, by flattening the overglaze layer 6 on the upper surfaces of the heating resistor 4 and the dummy resistor, the image quality improving effect can be further enhanced. The flattening of the overglaze layer 6 is performed by selecting the viscosity and the wettability of the material forming the overglaze layer, and after forming the overglaze layer material in multiple layers to form the overglaze layer with a thickness equal to or larger than that of the heating resistor and the dummy resistor. It is possible to adopt a method of polishing and flattening by lapping treatment.
It should be noted that the above numerical values are merely examples, and the present invention provides a dummy resistor that is separated from the resistor that contributes to heat generation at a fixed distance at the end of the resistor that contributes to heat generation in the sub-scanning direction. It is possible to improve the image quality by eliminating the generation of indentations on the recording medium.
【0017】図4はSST強度測定結果を示す説明図で
あって、前記で説明したように、(a)が従来サイズ、
(b)が上記巨大サイズ、(c)が本発明の一実施例に
おけるSST強度測定結果を示す説明図で、テスト時間
(SSTtime)を20sec,印加パルス幅(pu
lse width)を6msec,パルス周期を20
msec,ドロップ電圧(drop voltage)
を0.5Vとして、横軸に印加電力(W ワット)を、
縦軸に抵抗偏差(resistance varian
ce パーセント)をとって示している。(a)(b)
については、前記で説明済みである。(c)は本発明の
一実施例のサーマルヘッドにおける発熱抵抗体のSST
結果であり、この結果から顕かなように、(a)の従来
技術によるサーマルヘッドと同等のSST強度が得られ
ることが分かる。すなわち、ダミー抵抗体を設けること
により、発熱抵抗体ペーストの焼成時に焼成の加熱によ
る抵抗体の収縮が3箇所に分散するため、内部歪みの絶
対値が小さくなってSST強度が良好となる。なお、上
記実施例は、個別対向型の厚膜型サーマルヘッドに本発
明を適用したものであるが、本発明はこれに限定される
ものではなく、交互リード型の厚膜型サーマルヘッドに
適用することも可能である。また、インクリボンと普通
紙を使用するインク溶着転写型感熱式記録装置に用いら
れる厚膜型サーマルヘッド、あるいは感熱記録媒体を用
いる記録装置に本発明を適用することもできる。FIG. 4 is an explanatory view showing the SST intensity measurement results. As described above, (a) is the conventional size,
(B) is the above-mentioned huge size, (c) is an explanatory view showing the SST intensity measurement result in one embodiment of the present invention, the test time (SSTtime) is 20 sec, the applied pulse width (pu)
lse width) for 6 msec and a pulse period of 20
msec, drop voltage (drop voltage)
Is 0.5 V, the applied power (W watt) is on the horizontal axis,
The vertical axis represents the resistance deviation
ce percentage). (A) (b)
Has already been described above. (C) is the SST of the heating resistor in the thermal head of one embodiment of the present invention
As is clear from these results, it can be seen that the SST strength equivalent to that of the conventional thermal head of (a) can be obtained. That is, by providing the dummy resistor, the shrinkage of the resistor due to the heating during firing is dispersed at the time of firing the heating resistor paste, so that the absolute value of the internal strain becomes small and the SST strength becomes good. In addition, although the present invention is applied to the thick film type thermal head of the individual facing type in the above-mentioned embodiment, the present invention is not limited to this, and is applied to the alternate lead type thick film type thermal head. It is also possible to do so. The present invention can also be applied to a thick film type thermal head used in an ink fusion transfer type thermal recording apparatus using an ink ribbon and plain paper, or a recording apparatus using a thermal recording medium.
【0018】[0018]
【発明の効果】以上説明したように、本発明によれば、
副走査方向における発熱抵抗体副走査幅の端部にダミー
抵抗体を設けることによって、副走査方向の発熱抵抗体
エッジ部すなわちオーバーグレーズ層のエッジ部が記録
媒体の変形をもたらすことがなく、昇華方式の厚膜型サ
ーマルヘッドとして用いたときの記録媒体の表面状態を
略平滑に保ち、良好な画質の記録を行なうことができ
る。また、発熱抵抗体の製作工程におけるフォトレジス
ト柱の主走査方向幅を厚くせずに発熱抵抗体を形成でき
るので、該発熱抵抗体の主走査方向幅を狭くすることな
く製造歩留りを向上でき、さらに、SST強度も良好に
維持できる。As described above, according to the present invention,
Heating resistor in the sub-scanning direction By providing the dummy resistor at the end of the sub-scanning width, the edge of the heating resistor in the sub-scanning direction, that is, the edge of the overglaze layer does not cause deformation of the recording medium, and the sublimation is performed. The surface condition of the recording medium when used as a thick film type thermal head of the system can be kept substantially smooth, and recording with good image quality can be performed. Further, since the heating resistor can be formed without increasing the width of the photoresist pillar in the main scanning direction in the manufacturing process of the heating resistor, the manufacturing yield can be improved without narrowing the width of the heating resistor in the main scanning direction, Further, the SST strength can be maintained well.
【図1】 本発明による厚膜型サーマルヘッドの一実施
例を説明する要部平面図である。FIG. 1 is a plan view of relevant parts for explaining an embodiment of a thick film thermal head according to the present invention.
【図2】 本発明による厚膜型サーマルヘッドの一実施
例を説明する図1の断面図である。FIG. 2 is a cross-sectional view of FIG. 1 illustrating an example of a thick film type thermal head according to the present invention.
【図3】 本発明の一実施例のサーマルヘッドで記録し
た記録媒体の(a)表面図と(b)断面図である。FIG. 3 is (a) a front view and (b) a cross-sectional view of a recording medium recorded by a thermal head according to an embodiment of the present invention.
【図4】 発熱抵抗体のSST強度の説明図である。FIG. 4 is an explanatory diagram of SST strength of a heating resistor.
【図5】 厚膜型サーマルヘッドを印字ヘッドとした昇
華式記録装置の要部説明図である。FIG. 5 is an explanatory view of a main part of a sublimation type recording apparatus using a thick film type thermal head as a print head.
【図6】 従来技術による個別対向型の厚膜型サーマル
ヘッドの構造を説明する要部平面図である。FIG. 6 is a plan view of relevant parts for explaining the structure of an individually opposed thick film thermal head according to a conventional technique.
【図7】 従来技術による個別対向型の厚膜型サーマル
ヘッドの構造を説明する図6の(a)A−A線に沿った
副走査方向断面と(b)B−B線に沿った主走査方向断
面である。FIG. 7 is a cross-sectional view in the sub-scanning direction taken along the line AA of FIG. 6 and a main portion taken along the line BB of FIG. It is a cross section in the scanning direction.
【図8】 従来技術による個別対向型の厚膜型サーマル
ヘッドを用いた記録状態を微視的に示した模式図であ
る。FIG. 8 is a schematic view microscopically showing a recording state using an individually opposed type thick film thermal head according to a conventional technique.
【図9】 発熱抵抗体形成工程における発熱抵抗体形成
用フォトレジストパターンの説明図であって、(a)は
従来のサーマルヘッド製作用のフォトレジストパター
ン、(b)は本発明によるサーマルヘッド製作用のフォ
トレジストパターンの一実施例を示す。9A and 9B are explanatory views of a photoresist pattern for forming a heating resistor in a heating resistor forming step, wherein FIG. 9A is a conventional photoresist pattern for manufacturing a thermal head, and FIG. 9B is a thermal head manufacturing according to the present invention. An example of a photoresist pattern for use in the present invention is shown.
1・・・・セラミック基板、2・・・・共通電極、3・
・・・個別電極、4・・・・発熱抵抗体、5a・・・・
ダミー抵抗体、5b・・・・ダミー抵抗体、6・・・・
オーバーグレーズ(保護層)。1 ... Ceramic substrate, 2 ... Common electrode, 3 ...
... Individual electrodes, 4 ... Heating element, 5a ...
Dummy resistor, 5b ... Dummy resistor, 6 ...
Overglaze (protective layer).
Claims (1)
立して対向し主走査方向に配置される複数の個別電極
と、上記共通電極と個別電極のそれぞれの上に、副走査
方向に橋絡する発熱抵抗体と、上記共通電極,個別電極
および発熱抵抗体を覆う保護層とを有する厚膜型サーマ
ルヘッドにおいて、 前記共通電極と個別電極のそれぞれの上に、前記発熱抵
抗体の副走査方向端部に隣接してダミー抵抗体を設けた
ことを特徴とする厚膜型サーマルヘッド。1. A common electrode, a plurality of individual electrodes facing each other independently of each other in the main scanning direction, and a bridge in the sub-scanning direction on each of the common electrode and the individual electrode. In a thick film type thermal head having a heating resistor that is entangled and a protective layer that covers the common electrode, the individual electrode, and the heating resistor, a sub-scan of the heating resistor is provided on each of the common electrode and the individual electrode. A thick film type thermal head characterized in that a dummy resistor is provided adjacent to the end in the direction.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8943091A JPH0569570A (en) | 1991-03-29 | 1991-03-29 | Thick film type thermal head |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8943091A JPH0569570A (en) | 1991-03-29 | 1991-03-29 | Thick film type thermal head |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0569570A true JPH0569570A (en) | 1993-03-23 |
Family
ID=13970448
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP8943091A Pending JPH0569570A (en) | 1991-03-29 | 1991-03-29 | Thick film type thermal head |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0569570A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2005070683A1 (en) * | 2004-01-26 | 2005-08-04 | Rohm Co., Ltd. | Thermal print head |
US7097280B2 (en) | 2004-02-12 | 2006-08-29 | Lexmark International, Inc. | Printheads having improved heater chip construction |
-
1991
- 1991-03-29 JP JP8943091A patent/JPH0569570A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2005070683A1 (en) * | 2004-01-26 | 2005-08-04 | Rohm Co., Ltd. | Thermal print head |
US7352381B2 (en) | 2004-01-26 | 2008-04-01 | Rohm Co., Ltd. | Thermal print head |
US7097280B2 (en) | 2004-02-12 | 2006-08-29 | Lexmark International, Inc. | Printheads having improved heater chip construction |
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