JPH01218855A - Printing apparatus - Google Patents

Printing apparatus

Info

Publication number
JPH01218855A
JPH01218855A JP63046209A JP4620988A JPH01218855A JP H01218855 A JPH01218855 A JP H01218855A JP 63046209 A JP63046209 A JP 63046209A JP 4620988 A JP4620988 A JP 4620988A JP H01218855 A JPH01218855 A JP H01218855A
Authority
JP
Japan
Prior art keywords
thermal head
voltage detection
resistance value
value
printing
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
JP63046209A
Other languages
Japanese (ja)
Inventor
Akitoshi Aritaka
有高　明敏
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP63046209A priority Critical patent/JPH01218855A/en
Publication of JPH01218855A publication Critical patent/JPH01218855A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/315—Typewriters 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
    • B41J2/32—Typewriters 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
    • B41J2/35—Typewriters 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 providing current or voltage to the thermal head
    • B41J2/355—Control circuits for heating-element selection

Abstract

PURPOSE:To detect the resistance value of a thermal head in a state mounted to a printing apparatus and to easily judge the quality of the thermal head, by measuring the voltage of the resistor element connected to the heat generating element of the thermal head and controlling a switching element so as to shortcircuit the resistor element at the time of printing. CONSTITUTION:When the number of printing papers reach a prescribed value, a control part 1 opens the measuring terminal G1-G2 of a voltage detection part 10 by a switching element SW to make the input of a voltage detection circuit ADC effective. The value of the current flowing through the resistor element of a thermal head is measured by the voltage detection circuit ADC. This operation is repeated n-times up to the final heat generating resistor element. The control part I inspects the change of a resistance value on the basis of the measured data. The life of a heat generator resistance value is usually set to the point of time when the change quantity from the initial resistance value reaches 10% or more and the damage of a resistor can be easily judged because a current value I reaches O.

Description

【発明の詳細な説明】 産業上の利用分野 本発明はファクシミリ等に用いられるサーマルヘッドを
用いた印字装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a printing device using a thermal head used in facsimiles and the like.

従来の技術 従来より０、保守が容易である利点を生かしてファクシ
ミリ等の印字装置として、サーマルヘッドを用いた感熱
印字が多用されてきた。これらの印字装置に用いられる
サーマルヘッドは発熱抵抗体にパルス状の電流を供給し
、熱パルスを感熱紙に伝達し、発色させるものである。2. Description of the Related Art Thermal printing using a thermal head has been widely used in printing devices such as facsimile machines due to its ease of maintenance. The thermal head used in these printing devices supplies a pulsed current to a heating resistor, transmits the heat pulse to the thermal paper, and causes the paper to develop color.

発明が解決しようとする問題点 しかしながら、上記したサーマルヘッドは過電力又は機
械的摩耗などによって発熱体素子が損傷を受けた場合に
、外観上の異常を伴わないと実印字動作を行わなければ
良否の判定が出来ないという問題点を有していた。Problems to be Solved by the Invention However, if the heating element is damaged due to overpowering or mechanical wear, the above-mentioned thermal head cannot function properly unless actual printing operation is performed unless there is an abnormality in appearance. The problem was that it was not possible to make a determination.

又製造工程の不良等によって発熱抵抗値の異常に小さい
サーマルヘッドが製造され、このようなサーマルヘッド
を印字装置に組み込んだ場合、ヘッドの制御回路に異常
な電流が流れて制御回路に損傷を与える場合があった。Furthermore, if a thermal head with an abnormally small heating resistance value is manufactured due to a defect in the manufacturing process, and such a thermal head is incorporated into a printing device, an abnormal current will flow through the head's control circuit, causing damage to the control circuit. There was a case.

問題点を解決するための手段 本発明は、上記問題点を解決するためサーマルヘッドの
発熱素子と直列に接続された抵抗素子と、抵抗素子と並
列に接続された開閉素子と、抵抗素子の両端の電圧を検
知する電圧検知回路を備え、印字動作時は開閉素子を閏
にし非印字動作時は開閉素子を開にするとともに電圧検
知回路の出力信号を見て抵抗素子の両端の電圧が特定の
範囲より外にある場合警報を出力する制御手段を有した
ものである。Means for Solving the Problems In order to solve the above problems, the present invention provides a resistor element connected in series with the heating element of the thermal head, a switching element connected in parallel with the resistor element, and both ends of the resistor element. Equipped with a voltage detection circuit that detects the voltage of the resistance element, the switching element is incremented during printing operation, and the switching element is opened during non-printing operation, and the output signal of the voltage detection circuit is checked to detect the voltage across the resistance element. It has a control means that outputs an alarm when the temperature is outside the range.

作　　用 この構成によってサーマルヘッドの抵抗値の異常の検出
が可能となり、サーマルヘッドを印字装置に取り付けた
状態でサーマルヘッドの良否判定を行える。Function: With this configuration, it is possible to detect an abnormality in the resistance value of the thermal head, and it is possible to determine the quality of the thermal head while the thermal head is attached to the printing device.

実施例 以下本発明の一実施例について、図面を参照しながら説
明する。EXAMPLE An example of the present invention will be described below with reference to the drawings.

第１図は本発明の一実施例に於けるサーマルヘッド部の
ブロック図でありサーマルヘッドの構成を示すものであ
る。FIG. 1 is a block diagram of a thermal head section in one embodiment of the present invention, showing the structure of the thermal head.

第１図に於て、Ｒ１ａ＝Ｒｎｂは発熱抵抗体、Ｔ１〜Ｔ
ｎはヘッド駆動トランジスタ、Ａ１〜八〇はゲート、Ｄ
はデータ出力素子であり、これらは従来より一般的なも
のであるので詳細な説明を省略する。In Fig. 1, R1a=Rnb is a heating resistor, T1 to T
n is a head drive transistor, A1 to 80 are gates, D
are data output elements, and since these are conventionally common elements, detailed explanations will be omitted.

Ｒｓは駆動トランジスタＴ１〜Ｔｎのエミッタ部に一端
を接続するとともに両端をヘッド外部に端子Ｇｌ、Ｇ２
として引きだした抵抗素子である。One end of Rs is connected to the emitters of the drive transistors T1 to Tn, and both ends are connected to terminals Gl and G2 to the outside of the head.
This is a resistance element drawn out as follows.

第２図は本発明の一実施例に於けるサーマルヘッド電流
検知部のブロック図であり、Ｇ１．Ｇ２はヘッド端子、
ＳＷは開閉素子、ＡＤＣは電圧検知回路である。FIG. 2 is a block diagram of a thermal head current detection section in an embodiment of the present invention, and shows G1. G2 is the head terminal,
SW is a switching element, and ADC is a voltage detection circuit.

第３図は本発明の印字装置を用いたファクシミリ装置の
構成を示すブロック図である。FIG. 3 is a block diagram showing the configuration of a facsimile machine using the printing device of the present invention.

第３図において２は操作部、３は外部機器とのインター
フェイス部、４は読み取りセンサーで５のセンサー回路
部に接続される。６は原稿駆動モータ、７は原稿駆動プ
ラテンで８の駆動回路により駆動される。９はサーマル
ヘッド、１１はヘッド駆動回路、１２は印字駆動モータ
、１３は印字プラテンで１４の印字駆動回路とともに印
字装置を構成する。これらは従来のファクシミリと同よ
うなものであり、その動作の説明は省略する。In FIG. 3, reference numeral 2 denotes an operating section, 3 an interface section with external equipment, and 4 a reading sensor connected to a sensor circuit section 5. Reference numeral 6 is a document drive motor, and 7 is a document drive platen, which is driven by a drive circuit 8. 9 is a thermal head, 11 is a head drive circuit, 12 is a print drive motor, and 13 is a print platen, which together with 14 print drive circuits constitute a printing device. These are similar to conventional facsimile machines, and a description of their operations will be omitted.

１は本発明の要部をなす抵抗値の測定及び判定を行うマ
イクロプロセサを中心とした制御回路部であり、ｌＯは
第２図に示した電圧検知部である。Reference numeral 1 denotes a control circuit section mainly including a microprocessor for measuring and determining resistance values, which is an important part of the present invention, and lO is a voltage detection section shown in FIG.

又第４図はヘッド電流の測定シーケンスを示すフローチ
ャートである。FIG. 4 is a flowchart showing the head current measurement sequence.

以上のように構成されたファクシミリ装置の制御部１に
ついて、以下その動作を説明する。The operation of the control section 1 of the facsimile machine configured as described above will be described below.

今、本印字装置を搭載したファクシミリ装置が予め定め
られた枚数を印字しサーマルヘッドのチエツクを行うも
のとする。先ず制御部１は印字枚数をページ毎にチエツ
クしくステップ１）、規定の枚数に到達した場合は電圧
検知部１０の測定端子Ｇ１−Ｇ２を開閉素子ＳＷにて開
放し、電圧検知回路ＡＤＣの入力を有効とする。（ステ
ップ２）続いてヘッド駆動回路１１を介しデータ出力素
子りをクリアし、（ステップ３）測定シーケンスへ進む
。ステ、ツブ４の測定シーケンスではサーマルヘッド９
の第１ドツトの発熱抵抗体Ｒ１ａ。Now, it is assumed that a facsimile machine equipped with this printing device prints a predetermined number of sheets and checks the thermal head. First, the control section 1 checks the number of printed sheets for each page (Step 1), and when the specified number of sheets is reached, the measurement terminals G1-G2 of the voltage detection section 10 are opened by the switching element SW, and the input of the voltage detection circuit ADC is performed. shall be valid. (Step 2) Next, the data output element is cleared via the head drive circuit 11, and (Step 3) the process proceeds to the measurement sequence. In the measurement sequence of step and knob 4, thermal head 9
The heating resistor R1a of the first dot.

Ｒｌｂから順次に駆動トランジスタＴ１をゲートＡ１を
介してＯＮＬ、、抵抗素子Ｒｓを流れる電流値を電圧検
知回路ＡＤＣにて測定する。これを最終発熱抵抗素子ま
でｎ回繰り返す。この後、制御部１は開閉素子ＳＷによ
り測定端子Ｇ　１−０２を短絡し、実動作可能に戻す。The voltage detection circuit ADC measures the value of the current flowing sequentially from Rlb through the drive transistor T1 through the gate A1 to ONL, and through the resistance element Rs. This is repeated n times until the final heating resistor element is reached. Thereafter, the control section 1 short-circuits the measurement terminal G1-02 using the switching element SW, and returns the device to actual operation.

（ステップ５）ここで制御部１は測定したデータに基づ
き、抵抗値の変化を検査する。（ステップ６）駆動トラ
ンジスタのコレクターエミッタ間電圧をＶｃｅ、発熱体
抵抗Ｒｈ、測定抵抗Ｒｓ、供給電圧Ｖｃｃ、電流値！と
すると発熱体抵抗は次式で計算される。(Step 5) Here, the control unit 1 inspects the change in resistance value based on the measured data. (Step 6) The collector-emitter voltage of the drive transistor is Vce, the heating element resistance Rh, the measurement resistance Rs, the supply voltage Vcc, and the current value! Then, the heating element resistance is calculated by the following formula.

Ｒｈ＝　（Ｖｃ　ｃ−Ｖｃ　ｅ−ＶＲｓ　）　／　１但
しＶＲｓ＝ＩＸＲｓ 従って発熱体抵抗Ｒｈの変化は電流値Ｉの変化によって
計算可能である。ここで発熱体抵抗値の寿命は一般に初
期抵抗値からの変化分が１０％以上にて寿命とされ、ま
た抵抗体の損傷では電流値１　′がＯとなり容易に判定
可能である。制御部ｌが異常なドツトを検知した場合は
、ステップ７へ進みアラームにより操作者へ報知し動作
を停止する。Rh=(Vcc-Vce-VRs)/1 However, VRs=IXRs Therefore, the change in the heating element resistance Rh can be calculated by the change in the current value I. Here, the life of the resistance value of the heating element is generally considered to be the end of life when the change from the initial resistance value is 10% or more, and in the case of damage to the resistor, the current value 1' becomes O, which can be easily determined. If the control unit 1 detects an abnormal dot, the process proceeds to step 7, where an alarm is issued to notify the operator and the operation is stopped.

一方正常な場合はステップ８の次工程へ進む。On the other hand, if it is normal, proceed to the next process of step 8.

本発明の説明において印字動作途中の動作を説明したが
ヘッドの交換などを行った場合は、初期の電源投入シー
ケンス甲に前記ステップ２からの動作を組み込むことで
、ヘッド交換に対応できることは明らかであり、説明は
省略する。In the description of the present invention, the operation during the printing operation was explained, but it is clear that when the head is replaced, etc., it is possible to cope with the head replacement by incorporating the operation from step 2 into the initial power-on sequence A. Yes, the explanation will be omitted.

発明の効果 以上のように本発明は、非印字動作時には印字装置の主
要部であるサーマルヘッドの発熱素子に直列に接続され
た供給され抵抗素子の電圧を測定し、また印字時には抵
抗素子を短絡するよう開閉素子を制御する制御回路を設
けたため、サーマルヘッドを印字装置に取り付けた状態
でサーマルヘッドの抵抗値の検出が可能となり、容易に
サーマルヘッドの良否判定が行える。その結果、サーマ
ルヘッドの特性劣化及びヘッド交換時を容易に知ること
ができ、また不良のサーマルヘッドを取り付けることに
よって生じる故障等の除去を行うことができ、使用者に
よる印字装置の保守をなどを容易に行うことができると
いう効果を奏するものである。Effects of the Invention As described above, the present invention measures the voltage of the resistive element connected in series with the heating element of the thermal head, which is the main part of the printing device, during non-printing operations, and short-circuits the resistive element during printing. Since a control circuit is provided to control the opening/closing element so that the thermal head is attached to the printing device, the resistance value of the thermal head can be detected, and the quality of the thermal head can be easily determined. As a result, it is possible to easily know when the characteristics of the thermal head have deteriorated and when to replace the head, and it is also possible to eliminate failures caused by installing a defective thermal head, and to reduce the maintenance of the printing device by the user. This has the effect of being easy to perform.

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

”第１図は本発明の一実施例に於けるサーマルヘッドの
ブロック図、第２図は本発明の一実施例に於けるサーマ
ルヘッド電流検知部のブロック図、第３図は本発明の印
字装置を用いたファクシミリ装置の構成を示すブロック
図、第４図はヘッド電流の測定シーケンスを示すフロー
チャートである。 １・・・・・・・・制御回路部 ２・・・・・・・・操作部 ３・・・・・・・・インターフェイス部４・・・・・・
・・読み取りセンサー ５・・・・・・・・センサー回路部 ６・・・・・・・・原稿駆動モータ ７・・・・・・・・原稿駆動プラテン ８・・・・・・・・駆動回路 ９・暢・拳・拳・・サーマルへ・ソド １０・・・・・・・電圧検知部 １１・・・・・・・ヘッド駆動回路 １２・・・・・・・印字駆動モー°り １３・・・・・・・印字プラテン １４・・・・・・・印字駆動回路 １５・・・・・・・印字駆動回路 Ｒｌａ−Ｒｎｂ・・発熱抵抗体 Ｔ１〜Ｔｎ・・・・駆動トランジスタ Ａ１〜Ａｎ・・・・ゲート Ｄ・・・・・・・・データ出力素子 Ｒｓ・・・・・・・抵抗素子 Ｇｌ、Ｇ２・・・・ヘッド端子 ＳＷ・・・・・・・開閉素子 ＡＤＣ・・・・・・電圧検知回路"Figure 1 is a block diagram of a thermal head in an embodiment of the present invention, Figure 2 is a block diagram of a thermal head current detection section in an embodiment of the present invention, and Figure 3 is a block diagram of a thermal head in an embodiment of the present invention. A block diagram showing the configuration of a facsimile machine using the device, and FIG. 4 is a flowchart showing the head current measurement sequence. 1. Control circuit section 2. Operation. Section 3...Interface section 4...
...Reading sensor 5...Sensor circuit section 6...Document drive motor 7...Document drive platen 8...Driving Circuit 9・Fist・Fist・・To thermal・Sodo 10・・・・・Voltage detection part 11・・・・・Head drive circuit 12・・・Print drive mode 13 ......Print platen 14...Print drive circuit 15...Print drive circuit Rla-Rnb...Heating resistor T1~Tn...Drive transistor A1~ An...Gate D...Data output element Rs...Resistance element Gl, G2...Head terminal SW...Switching element ADC... ...Voltage detection circuit

Claims (1)

【特許請求の範囲】[Claims] 複数個の発熱素子と駆動素子を搭載したサーマルヘッド
と、前記駆動素子の共通接地配線部に接続された抵抗素
子と、前記抵抗素子と並列に接続された開閉素子と、前
記抵抗素子の両端の電圧を検知する電圧検知回路を備え
、印字動作時は前記開閉素子を閉にし非印字動作時は前
記開閉素子を開にするとともに前記電圧検知回路の出力
信号を見て前記抵抗素子の両端の電圧が特定の範囲より
外にある場合警報を出力する制御手段を有することを特
徴とする印字装置。A thermal head equipped with a plurality of heating elements and drive elements, a resistance element connected to a common ground wiring section of the drive element, a switching element connected in parallel to the resistance element, and a thermal head at both ends of the resistance element. It is equipped with a voltage detection circuit that detects voltage, and closes the switching element during printing operation, opens the switching element during non-printing operation, and detects the voltage across the resistance element by checking the output signal of the voltage detection circuit. 1. A printing device characterized by having a control means for outputting an alarm when the value is outside a specific range.
JP63046209A 1988-02-29 1988-02-29 Printing apparatus Pending JPH01218855A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP63046209A JPH01218855A (en) 1988-02-29 1988-02-29 Printing apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63046209A JPH01218855A (en) 1988-02-29 1988-02-29 Printing apparatus

Publications (1)

Publication Number Publication Date
JPH01218855A true JPH01218855A (en) 1989-09-01

Family

ID=12740698

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63046209A Pending JPH01218855A (en) 1988-02-29 1988-02-29 Printing apparatus

Country Status (1)

Country Link
JP (1) JPH01218855A (en)

Similar Documents

Publication Publication Date Title
US6199969B1 (en) Method and system for detecting nonfunctional elements in an ink jet printer
JP5720098B2 (en) Head element operation confirmation mechanism and head element operation confirmation method
US4769657A (en) Fault detection device for thermal printing head heating circuits
WO2010066162A1 (en) A thermal printhead detecting device and method and a thermal printer using the same
JPH01218855A (en) Printing apparatus
JP5915704B2 (en) Head element number confirmation method and head element number confirmation mechanism
US7940288B2 (en) Print control device for a thermal printer
JPH05238038A (en) Control system of resistance measurement of thermal head
JPH0926451A (en) Deterioration diagnosing device for relay coil
JP2954049B2 (en) Thermal head
JP2002258688A (en) Image forming apparatus
JPH0637781U (en) Inspection device for pull-up resistance
JPH07285234A (en) Thermal head measuring circuit and printer
JPH05169706A (en) Apparatus for detecting defect of print head and printer controlling apparatus
JPH05104763A (en) Dot inspection device of thermal printer
KR960012517B1 (en) A current trans inspection apparatus and method of dryer
JPH04236117A (en) Overload protective device
JPH05212906A (en) Image forming device
JPH03193367A (en) Thermal recorder
JPH074641Y2 (en) Fixing temperature control circuit
JPH0474653A (en) Dot printer
JP3235465B2 (en) Printer
JPH0410864B2 (en)
JPH04296567A (en) Burning prevention device of printer printing head
JPH029645A (en) Thermal line printer