JPS6120761A - Temperature controlling circuit for thermal head - Google Patents

Temperature controlling circuit for thermal head

Info

Publication number
JPS6120761A
JPS6120761A JP59140681A JP14068184A JPS6120761A JP S6120761 A JPS6120761 A JP S6120761A JP 59140681 A JP59140681 A JP 59140681A JP 14068184 A JP14068184 A JP 14068184A JP S6120761 A JPS6120761 A JP S6120761A
Authority
JP
Japan
Prior art keywords
posistor
comparator
thermal head
thermistor
temperature
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.)
Pending
Application number
JP59140681A
Other languages
Japanese (ja)
Inventor
Kazufumi Naito
和文 内藤
Kazuhiko Takemura
和彦 竹村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ishida Scales Manufacturing Co Ltd
Ishida Co Ltd
Original Assignee
Ishida Scales Manufacturing Co Ltd
Ishida Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ishida Scales Manufacturing Co Ltd, Ishida Co Ltd filed Critical Ishida Scales Manufacturing Co Ltd
Priority to JP59140681A priority Critical patent/JPS6120761A/en
Publication of JPS6120761A publication Critical patent/JPS6120761A/en
Pending legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/315Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material
    • B41J2/32Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads
    • B41J2/375Protection arrangements against overheating

Abstract

PURPOSE:To make a thermal head to be protected from a trouble of overheatong by a method wherein the electric current to a posistor is cut off by detecting troubles such as a disconnection or an inferior contact in a signal line connected to a thermister mounted on a thermal head. CONSTITUTION:As the resistances r2, r3 are determined so that the input voltage E0, E1 of a comparator OP1 is in the condition of E1>E0, when a sigal line L1 is in normal condition, L1 is outputted and make the switch Sa OFF and the switch Sb in ON. As the variable resistance VR is adjusted so that the input voltages E2, E3 are in the condition of E3>E2 at more than the preheat temperature, when the temperature is in less than the preheat temperature the posistor is heated up. When the troubles such as a disconnection or a inferior contact in a signal line occurs, the comparator OP1 outputs H in the condition of E0>E1 since the resistance of thermistor 3 becomes infinitive and the electric current to the posistor is cut off.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は、サーマルプリンタ等の記録装置に用いられる
サーマルヘッドの温度制御回路の改良に関する。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a temperature control circuit for a thermal head used in a recording device such as a thermal printer.

(従来技術) サーマルプリンタは、複数の発熱素子をサーマルヘッド
上に直線状に配置し、発熱素子に対向、接触させた感熱
ラベル等の感熱紙を所定ピッチで走行させると共に、感
熱素子を印字データに応じて選択的に発熱させることに
より、感熱ラベル等の上に所定のパターンを発色、印刷
させるものである。
(Prior art) A thermal printer has a plurality of heating elements arranged in a straight line on a thermal head, and runs thermal paper such as a thermal label facing and in contact with the heating elements at a predetermined pitch. By selectively generating heat according to the temperature, a predetermined pattern is colored and printed on a heat-sensitive label or the like.

第6図はこのようなサーマルプリンタに用いるサーマル
ヘッドの配属図である。図において、発熱素子のパター
ン4が配置されるサーマルヘッド1にポジスタ2を取り
付ける。感熱紙は規定の発色温度以上で急激に発色する
ので、サーマルヘッドを、発色温度以下の所定の予熱温
度に暖めておくと、発熱素子を発熱させる際の応答性が
良好になることから、サーマルヘッドを所定の予熱温度
まで加熱する予熱用のポジスタが取付けられるものであ
る。また、サーマルヘッドの温度を検出するサーミスタ
3が配置されており、信号ラインLlを通して検出信号
を温度制御回路5に送り、温度制御回路からポジスタ駆
動回路6にポジスタ2の通電を制御する信号Soが送出
される。
FIG. 6 is an arrangement diagram of a thermal head used in such a thermal printer. In the figure, a posister 2 is attached to a thermal head 1 on which a pattern 4 of heating elements is arranged. Thermal paper rapidly develops color when it exceeds the specified coloring temperature, so if you warm the thermal head to a predetermined preheating temperature that is below the coloring temperature, the responsiveness when generating heat from the heating element will be better. A preheating posister is attached to the head to heat the head to a predetermined preheating temperature. Further, a thermistor 3 for detecting the temperature of the thermal head is arranged, and a detection signal is sent to the temperature control circuit 5 through the signal line Ll, and a signal So for controlling the energization of the POSISTOR 2 is sent from the temperature control circuit to the POSISTOR drive circuit 6. Sent out.

(従来技術の問題点) このようなサーマルヘッドの使用中には、種々の原因に
より局部的な過熱を生じることがあり、その対策として
サーマルヘッドを強制冷却したり、また特開昭58−5
5262号公報に提案されているように、発熱部分を所
定の処理が終了する毎に所定ピッチずらせるように構成
したものがあった・ しかしながら、サーミスタの信号ラインL1が断線した
り、その信号ラインのコネクタに接触不良が生じる等の
事故が発生すると、サーミスタは加熱前の検出状態と等
価になるため、温度制御回路はサーマルヘッドが低温状
態であると判断してポジスタには通電電流が流れ続ける
ので、遂にハ、サーマルヘッドをオーバーヒートサセて
ヘッドを破壊してしまうことがあり、これを防止する有
効な手段は講じられていなかった。例えば、このような
事故防止のために、ポジスタの発熱限界温度(設定温度
)をサーマルヘッドの所定の予熱温度まで下げることも
考えられるが、そうすると今度は、サーマルヘッドが所
定の予熱温度になるまでにかなりの時間(例えば10分
以上)がかかり、通電後直ちに使用出来ないという不便
を生じる。
(Problems with the prior art) When such a thermal head is used, local overheating may occur due to various causes, and as a countermeasure, the thermal head is forcibly cooled, and
As proposed in Publication No. 5262, there was a structure in which the heat generating part was shifted by a predetermined pitch each time a predetermined process was completed. However, the signal line L1 of the thermistor was disconnected, or the signal line If an accident occurs such as a poor contact in the connector, the thermistor will be in the same detection state as before heating, so the temperature control circuit will determine that the thermal head is in a low temperature state and the current will continue to flow through the POSISTOR. As a result, the thermal head may eventually overheat and be destroyed, and no effective means have been taken to prevent this. For example, in order to prevent such accidents, it may be possible to lower the heat generation limit temperature (set temperature) of POSISTOR to a predetermined preheating temperature of the thermal head. This results in the inconvenience that it takes a considerable amount of time (for example, 10 minutes or more) to do so, and that it cannot be used immediately after power is applied.

(発明の目的) 本発明は、サーミスタの信号ラインが断線したり、コネ
クタの接触不良が生じても、ポジスタの発熱限界温度を
落とさずにサーマルヘッドの過熱を防止するこができる
、新規な温度制御回路を提供することを目的とする。
(Object of the Invention) The present invention provides a novel temperature control system that can prevent overheating of the thermal head without lowering the heat generation limit temperature of the POSISTOR even if the thermistor signal line is disconnected or the connector has a poor contact. The purpose is to provide a control circuit.

(発明の概要) 本発明のサーマルヘッドの温度制御回路は、ポジスタに
より予熱されるサーマルヘッドの温度を検出するサーミ
スタ、一方端子にはサーミスタの出力信号が、他方端子
には分圧された基準電圧が印加されて、サーミスタの信
号ラインの事故を検知し得るように配置された第1の比
較器、第1の比較器の出力信号で駆動されるスイッチン
グ手段、−・方端子にはスイッチグ手段の出力側の電位
が、他方端子にはポジスタの設定温度に比例する電圧が
印加される第2の比較器を具備しサーミスタの信号ライ
ンが正常のときには、上記スイッチング手段を介して第
2の比較器よりポジスタの通電信号が出力され、サーミ
スタの信号ラインに事故が発生したときには第2の比較
器よりポジスタの通電を停止する信号が出力されるよう
に構成したものである。
(Summary of the Invention) The thermal head temperature control circuit of the present invention includes a thermistor that detects the temperature of the thermal head preheated by a POSISTOR, one terminal of which receives the output signal of the thermistor, and the other terminal of which is a divided reference voltage. a first comparator arranged so as to be able to detect a fault in the signal line of the thermistor; a switching means driven by the output signal of the first comparator; The potential on the output side is provided with a second comparator to which a voltage proportional to the set temperature of the POSISTOR is applied to the other terminal, and when the signal line of the thermistor is normal, the second comparator is connected via the switching means. The second comparator outputs a signal for energizing the POSISTOR, and when a fault occurs in the signal line of the thermistor, the second comparator outputs a signal for stopping the energization of the POSISTOR.

(実施例) 次に、図により本発明の一実施例について説明する。第
1図は本発明のサーマルヘッドの温度制御回路の回路図
である0図において、サーミスタ3の一端は基準電圧+
■の電源に、他端は第1の比較器OF、の一側端子に接
続される。第1の比較器OP1の+側端子は、分圧抵抗
r2、r3を介して基準電圧+■の電源に接続される。
(Example) Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram of the temperature control circuit of the thermal head of the present invention. In FIG. 0, one end of the thermistor 3 is connected to the reference voltage +
(2), and the other end is connected to one side terminal of the first comparator OF. The + side terminal of the first comparator OP1 is connected to the power source of the reference voltage +■ via voltage dividing resistors r2 and r3.

第1の比較器OF、の出力信号は、トランジスタTrの
ベースとスイッチSaに供給される。また、トランジス
タTrのコレクタ側の出力はスイッチsbに供給される
。スイッチSa、Sbの接続点は、第2の比較器OP2
の一側端子に接続され、第2の比較器の+側端子は分圧
抵抗r81 r91可変抵抗VRを介して基準電圧子V
の電源に接続され設定温度に比例した電圧が印加される
。第2の比′岐器OP2からは、ポジスタ駆動回路の駆
動信号Soが出力される。これによって、ポジスタの通
電または通電停止の制御を行なう。
The output signal of the first comparator OF is supplied to the base of the transistor Tr and the switch Sa. Further, the collector side output of the transistor Tr is supplied to the switch sb. The connection point between the switches Sa and Sb is the second comparator OP2.
It is connected to one side terminal, and the + side terminal of the second comparator is connected to the reference voltage V
A voltage proportional to the set temperature is applied. The second ratio divider OP2 outputs a drive signal So for the POSISTOR drive circuit. This controls the energization or de-energization of the POSISTOR.

尚、rloはスイッチング時のチャタリングを防止する
ための抵抗である。
Note that rlo is a resistance for preventing chattering during switching.

この温度制御回路は次のように動作する。This temperature control circuit operates as follows.

(1)サーミスタの信号ラインL1に断線やコネクタの
接触不良等の異常のない場合。
(1) If there is no abnormality in the thermistor signal line L1 such as disconnection or poor contact of the connector.

このときには、比較器OF、の入力電圧は、El >E
oとなるようにr2及びri!iの値を定めているので
、常に、 (a)比較器OPIの出力レベルはLとなる。
At this time, the input voltage of the comparator OF is El > E
r2 and ri! so that o! Since the value of i is determined, (a) the output level of comparator OPI is always L.

(b)トランジスタTrのコレクタ電位はHとなる。(b) The collector potential of the transistor Tr becomes H.

(C)スイッチSaはオフ、スイッチsbはオンの状態
になる。
(C) Switch Sa is turned off and switch sb is turned on.

また、比較器oP2の入力電圧E2.E、は、サーマル
ヘッドの所定の予熱温度以上ではE3>E2.以下では
E2 >E5となるように可変抵抗VRで調整されてい
るので、 (a)サーミスタの検出温度が上記予熱温度以下になれ
ば、比較器OP2の出力がHレベルになってポジスタを
加熱する。
In addition, the input voltage E2. of the comparator oP2. E is equal to or higher than a predetermined preheating temperature of the thermal head, E3>E2. In the following, since it is adjusted by variable resistor VR so that E2 > E5, (a) If the detected temperature of the thermistor becomes below the above preheating temperature, the output of comparator OP2 becomes H level and heats the POSISTOR. .

(b)また、サーミスタの検出温度が上記予熱温度以上
になれば、比較器OP2の出力がLレベルになってポジ
スタへの通電を停止させる。
(b) Furthermore, when the temperature detected by the thermistor becomes equal to or higher than the preheating temperature, the output of the comparator OP2 becomes L level, and the power supply to the POSISTOR is stopped.

(2)信号ラインL、に断線やコネクタの接触不良等の
事故が発生して異常がある場合。
(2) If there is an abnormality in the signal line L due to an accident such as a disconnection or poor contact of the connector.

この時には、サーミスタの抵抗値が無限大になるので、
EO>El となる。従って、(a)比較器OP、のレ
ベルはHとなる。
At this time, the resistance value of the thermistor becomes infinite, so
EO>El. Therefore, the level of (a) comparator OP becomes H.

(b)トランジスタTrのコレクタ電位はLとなる。(b) The collector potential of the transistor Tr becomes L.

(C)従って、スイ・ンチSaはオン、スイッチSbは
オフの状態になる。
(C) Therefore, the switch Sa is on and the switch Sb is off.

(d)すると、比較器OP2の入力レベルE2+E3は
g5>E2に固定されるので、その出力はLレベルに変
化し、ポジスタへの通電を停止させる。
(d) Then, since the input level E2+E3 of the comparator OP2 is fixed to g5>E2, its output changes to the L level, and the energization to the POSISTOR is stopped.

(3)信号ラインが正常に戻った場合。(3) When the signal line returns to normal.

このときには、比較器OPIの入力電圧はEl>E、と
なるので、比較器OP1の出力レベルはLに切り変わる
。従って、再びスイッチSaはオフ、sbはオンとなっ
て、サーミスタによる温度制御が可能になる。
At this time, the input voltage of the comparator OPI is El>E, so the output level of the comparator OP1 switches to L. Therefore, the switch Sa is turned off and the switch sb is turned on again, making it possible to control the temperature using the thermistor.

(発明の効果) 以上説明したように、本発明によるサーマルヘッドの温
度制御回路は、サーミスタの信号ラインの断線や接続不
良等の事故を検出して、このような事故が生じた時には
ポジスタへの通電を停止するように17だので、ポジス
タの急峻な発熱特性を落さずに、サーマルヘッドを過熱
事故から保護することができる。
(Effects of the Invention) As explained above, the temperature control circuit for a thermal head according to the present invention detects accidents such as disconnection or poor connection of the thermistor signal line, and when such an accident occurs, the temperature control circuit for the thermal head according to the invention 17 to stop energization, the thermal head can be protected from overheating without reducing the steep heat generation characteristics of the POSISTOR.

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

第1図は本発明の回路図、第2図は本発明の概略図であ
る。 1・・・サーマルヘッド、2・・・ポジスタ、3・・・
サーミスタ、4・・・発熱素子のパターン、5・・・温
度制御回路、6・・・ポジスタ駆動回路、OP、・・・
第1の比較器、OP2・・・第2の比較器。 特許出願人  株式会社 石田衡器製作所代  理  
人   弁理士   辻        實(外1名) 第1図 第2図
FIG. 1 is a circuit diagram of the present invention, and FIG. 2 is a schematic diagram of the present invention. 1...Thermal head, 2...Posistor, 3...
Thermistor, 4... Heat generating element pattern, 5... Temperature control circuit, 6... POSISTOR drive circuit, OP,...
First comparator, OP2... second comparator. Patent applicant: Ishida Kouki Seisakusho Co., Ltd.
People Patent attorney Minoru Tsuji (1 other person) Figure 1 Figure 2

Claims (1)

【特許請求の範囲】[Claims] ポジスタにより予熱されるサーマルヘッドの温度を検出
するサーミスタ、一方端子にはサーミスタの出力信号が
、他方端子には分圧された基準電圧が印加されて、サー
ミスタの信号ラインの事故を検知し得るように配置され
た第1の比較器、該第1の比較器の出力信号で駆動され
るスイッチング手段、一方端子には前記スイッチング手
段の出力側の電位が、他方端子にはポジスタの設定温度
に比例する電圧が印加される第2の比較器を具備し、サ
ーミスタの信号ラインが正常のときには、上記スイッチ
ング手段を介して第2の比較器よりポジスタの通電信号
が出力され、サーミスタの信号ラインに事故が発生した
ときには第2の比較器よりポジスタの通電を停止する信
号が出力されることを特徴とする、サーマルヘッドの温
度制御回路。
The thermistor detects the temperature of the thermal head preheated by the POSISTOR.The output signal of the thermistor is applied to one terminal, and the divided reference voltage is applied to the other terminal, so that it is possible to detect an error in the thermistor signal line. a first comparator disposed in the first comparator, a switching means driven by the output signal of the first comparator, one terminal having a potential on the output side of the switching means, and the other terminal having a voltage proportional to the set temperature of the POSISTOR. When the signal line of the thermistor is normal, the second comparator outputs the energization signal of the POSISTOR via the switching means, and the voltage is applied to the signal line of the thermistor. 1. A temperature control circuit for a thermal head, wherein a second comparator outputs a signal to stop energization of a POSISTOR when this occurs.
JP59140681A 1984-07-09 1984-07-09 Temperature controlling circuit for thermal head Pending JPS6120761A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59140681A JPS6120761A (en) 1984-07-09 1984-07-09 Temperature controlling circuit for thermal head

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59140681A JPS6120761A (en) 1984-07-09 1984-07-09 Temperature controlling circuit for thermal head

Publications (1)

Publication Number Publication Date
JPS6120761A true JPS6120761A (en) 1986-01-29

Family

ID=15274279

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59140681A Pending JPS6120761A (en) 1984-07-09 1984-07-09 Temperature controlling circuit for thermal head

Country Status (1)

Country Link
JP (1) JPS6120761A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6327286A (en) * 1986-07-18 1988-02-04 Nec Corp Printer
JPS6480555A (en) * 1987-09-24 1989-03-27 Aisin Seiki Thermal head protecting apparatus
JPH0195066A (en) * 1987-10-07 1989-04-13 Fuji Xerox Co Ltd Protector for thermal head
JPH01116665A (en) * 1987-10-30 1989-05-09 Fuji Xerox Co Ltd Light quantity control device such as printer using led head
JPH03216374A (en) * 1990-01-23 1991-09-24 Oki Electric Ind Co Ltd Thermal alarm detector of printing head
US5529408A (en) * 1986-11-26 1996-06-25 Canon Kabushiki Kaisha Thermal transfer recording method including preheating thermal transfer recording medium
JP2006062121A (en) * 2004-08-25 2006-03-09 Tohoku Ricoh Co Ltd Platemaking device and platemaking printer

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6327286A (en) * 1986-07-18 1988-02-04 Nec Corp Printer
US5529408A (en) * 1986-11-26 1996-06-25 Canon Kabushiki Kaisha Thermal transfer recording method including preheating thermal transfer recording medium
JPS6480555A (en) * 1987-09-24 1989-03-27 Aisin Seiki Thermal head protecting apparatus
JPH0195066A (en) * 1987-10-07 1989-04-13 Fuji Xerox Co Ltd Protector for thermal head
JPH01116665A (en) * 1987-10-30 1989-05-09 Fuji Xerox Co Ltd Light quantity control device such as printer using led head
JPH03216374A (en) * 1990-01-23 1991-09-24 Oki Electric Ind Co Ltd Thermal alarm detector of printing head
JP2006062121A (en) * 2004-08-25 2006-03-09 Tohoku Ricoh Co Ltd Platemaking device and platemaking printer
JP4651995B2 (en) * 2004-08-25 2011-03-16 東北リコー株式会社 Plate making apparatus and plate making printing apparatus

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