JPS62146649A - Thermal head protective circuit - Google Patents

Thermal head protective circuit

Info

Publication number
JPS62146649A
JPS62146649A JP60288832A JP28883285A JPS62146649A JP S62146649 A JPS62146649 A JP S62146649A JP 60288832 A JP60288832 A JP 60288832A JP 28883285 A JP28883285 A JP 28883285A JP S62146649 A JPS62146649 A JP S62146649A
Authority
JP
Japan
Prior art keywords
thermal head
transistor
pressed
state
printing paper
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
JP60288832A
Other languages
Japanese (ja)
Inventor
Hiromi Kaneko
金子　浩美
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.)
NEC Corp
Original Assignee
NEC Corp
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 NEC Corp filed Critical NEC Corp
Priority to JP60288832A priority Critical patent/JPS62146649A/en
Publication of JPS62146649A publication Critical patent/JPS62146649A/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
    • B41J2/375—Protection arrangements against overheating

Landscapes

  • Electronic Switches (AREA)

Abstract

PURPOSE:To make it possible to prevent the destruction of a thermal head even when a power source is not closed and even if the detachment of a thermal head is performed in such a state that the thermal head is not pressed to printing paper, by controlling the supply of a current to the thermal head on the basis of a signal such that the thermal head is pressed to printing paper. CONSTITUTION:A signal going to a high level when a thermal head is pressed but going to a low level at the other time is inputted to an inverter IC2. The output of the inverter IC2 is brought to an ON-state when the thermal head is pressed to printing paper and a current flows to the base of a transistor 1 through a resistor 3 to bring the transistor 1 to an ON-state and a power source for the thermal head supplies a current to the thermal head. The output of the inverter IC2 is brought to an OFF-state when the thermal head is not pressed to the printing paper and the base current of the transistor 1 does not flows and the transistor 1 goes to an OFF-state to supply no current to the thermal head.

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、特にサーマルヘッドの保護
回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal printer, and particularly to a protection circuit for a thermal head.

〔従来の技術〕[Conventional technology]

従来、この種のプリンタは、電源が投入されている間は
常にサーマルヘッドに通電されていて、サーマルヘッド
の通電を制御する回路は特になかった。Conventionally, in this type of printer, the thermal head is always energized while the power is turned on, and there is no particular circuit for controlling the energization of the thermal head.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

上述した従来のサーマルプリンタは、電源が投入されて
いる時でもサーマルヘッドの脱着が可能になっているの
で、誤ワて電源が投入された状態でサーマルヘッドの脱
着を行なってしまうと、サーマルヘッド脱着の時にサー
マルヘッド上に実装されたサーマルヘッド制御用ＩＣの
動作が不安定になり、サーマルヘッドの発熱体に異常に
長時間の通電がなされたり、号−マルヘッド制御用ＩＣ
Ｋ異常な電圧が印加され、サーマルヘッドが破壊してし
まうという欠点があった。In the conventional thermal printers mentioned above, the thermal head can be attached or detached even when the power is on, so if you accidentally attach or detach the thermal head while the power is on, the thermal head may During attachment and detachment, the operation of the thermal head control IC mounted on the thermal head may become unstable, and the heating element of the thermal head may be energized for an abnormally long time.
There was a drawback that an abnormal voltage was applied and the thermal head was destroyed.

〔問題点を解決するための手段〕[Means for solving problems]

本発明のサーマルヘッド保護回路は、サーマルヘッドに
対する通電をサーマルヘッドを印字用紙に押し付けてい
るときのみ行なう機能を有している。The thermal head protection circuit of the present invention has a function of energizing the thermal head only when the thermal head is pressed against printing paper.

〔実施例〕〔Example〕

次に本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.

第１図は本発明の一実施例の回路図である。トランジス
タ１はサーマルヘッド用電源とサーマルヘッドの間に接
続され、インバータＩＣ（オーブンコレクタ出力）２に
よって抵抗３を通して駆動される。抵抗４はトランジス
タ１のペースとサーマルヘッド用電源の間に接続される
。FIG. 1 is a circuit diagram of an embodiment of the present invention. A transistor 1 is connected between a thermal head power supply and a thermal head, and is driven by an inverter IC (oven collector output) 2 through a resistor 3. A resistor 4 is connected between the pace of the transistor 1 and the power supply for the thermal head.

インバータＩＣ２にはサーマルヘッドを押し付けている
時にハイ・レベル、それ以外はローレベルになる信号を
入力する。サーマルヘッドを押し付けている時にはイン
バータＩＣ２の出力はＯＮ状態となり、抵抗３を通して
トランジスタ１０ベースに電流が流れる。トランジスタ
１のペースに電流が流れる事により、トランジスタ１は
オン状態となりサーマルヘッド用電源がサーマルヘッド
に通電される。A signal is input to the inverter IC2 which is at a high level when the thermal head is being pressed, and which is at a low level at other times. When the thermal head is being pressed, the output of the inverter IC2 is in the ON state, and current flows through the resistor 3 to the base of the transistor 10. When a current flows through the transistor 1, the transistor 1 is turned on, and the thermal head power supply is applied to the thermal head.

サーマルヘッドが印字用紙に押し付けられていない時に
はインバータ２の出力がオフ状態となシトランジスタ１
のペース電流が流れずトランジスタ１はＯＦＦ状態とな
りサーマルヘッドには通電されない。When the thermal head is not pressed against the printing paper, the output of inverter 2 is off.
Since no pace current flows, transistor 1 is turned off and no current is applied to the thermal head.

〔発明の効果〕〔Effect of the invention〕

以上説明したように本発明は、サーマルヘッドを印字用
紙に押し付けていない時には印字動作を行なわない事か
ら、サーマルヘッドを印字用紙に押し付けているという
信号によってサーマルヘッドへの通電を制御することに
より、電源が投入されている時でも印字待ち状態のよう
にサーマルヘッドが印字用紙に押し付けられていない状
態に於いてサーマルヘッドの脱着を行なっても、サーマ
ルヘッドの破壊を防止する効果がある。As explained above, the present invention does not perform a printing operation when the thermal head is not pressed against the printing paper, so by controlling the energization to the thermal head based on a signal indicating that the thermal head is pressed against the printing paper, Even when the power is turned on and the thermal head is attached and detached in a state where the thermal head is not pressed against the printing paper, such as in a printing standby state, it is effective in preventing damage to the thermal head.

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

第１図は本発明のサーマルヘッド保護回路の一実施例の
回路図である。 １・・・・・・トランジスタ、２・・・・・・インバー
タＩＣ（オープンコレクタ出力）、３・・・・・・抵抗
、４・・・・・・抵抗。FIG. 1 is a circuit diagram of an embodiment of the thermal head protection circuit of the present invention. 1... Transistor, 2... Inverter IC (open collector output), 3... Resistor, 4... Resistor.

Claims (1)

【特許請求の範囲】[Claims] サーマルヘッドを印字用紙に押し付けている時のみサー
マルヘッドの発熱体に通電する機能を有したサーマルヘ
ッド保護回路。A thermal head protection circuit that has the function of energizing the heating element of the thermal head only when the thermal head is pressed against the printing paper.
JP60288832A 1985-12-20 1985-12-20 Thermal head protective circuit Pending JPS62146649A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP60288832A JPS62146649A (en) 1985-12-20 1985-12-20 Thermal head protective circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60288832A JPS62146649A (en) 1985-12-20 1985-12-20 Thermal head protective circuit

Publications (1)

Publication Number Publication Date
JPS62146649A true JPS62146649A (en) 1987-06-30

Family

ID=17735322

Family Applications (1)

Application Number Title Priority Date Filing Date
JP60288832A Pending JPS62146649A (en) 1985-12-20 1985-12-20 Thermal head protective circuit

Country Status (1)

Country Link
JP (1) JPS62146649A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109414939A (en) * 2016-10-05 2019-03-01 佐藤控股株式会社 Printer

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56159182A (en) * 1980-05-14 1981-12-08 Ricoh Co Ltd Thermosensitive recording device
JPS58193172A (en) * 1982-05-07 1983-11-10 Fujitsu Ltd Thermal printer

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56159182A (en) * 1980-05-14 1981-12-08 Ricoh Co Ltd Thermosensitive recording device
JPS58193172A (en) * 1982-05-07 1983-11-10 Fujitsu Ltd Thermal printer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109414939A (en) * 2016-10-05 2019-03-01 佐藤控股株式会社 Printer
EP3524435A4 (en) * 2016-10-05 2019-11-13 Sato Holdings Kabushiki Kaisha Printer
US10882330B2 (en) 2016-10-05 2021-01-05 Sato Holdings Kabushiki Kaisha Printer
CN109414939B (en) * 2016-10-05 2021-07-16 佐藤控股株式会社 Printer with a movable platen

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