【発明の詳細な説明】［産業上の利用分野］本発明は、時間的遅延を持つ手段により、発熱体への通
電しゃ断を行なう電力制御装置に関するもので、発熱体
としては、たとえば、トナー画像を記録材に加熱定着す
る定着装置などの発熱体を対象とするものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power control device that cuts off current to a heating element by means with a time delay. The object is a heat-generating body such as a fixing device that heats and fixes images onto a recording material.
［従来の技術］従来、電力制御による発熱体の電力制御装置は、発熱体
の異常温度時に、異常事態を解除するために、電力供給
回路をしゃ断装置により、しゃ断している。[Prior Art] Conventionally, in a power control device for a heating element using power control, when the temperature of the heating element is abnormal, a power supply circuit is cut off by a cutoff device in order to release the abnormal situation.
上記しゃ断装置は、たとえば、第４図の回路図のように
、機械的なしゃ断手段として、メカニカルリレー３０が
あり、このメカニカルリレー３０の駆動装置は、半導体
３１、電流ヒユーズ３２の二段構えで構成されている。For example, as shown in the circuit diagram of FIG. 4, the above-mentioned breaker device includes a mechanical relay 30 as a mechanical breaker, and the drive device for this mechanical relay 30 is a two-stage structure including a semiconductor 31 and a current fuse 32. It is configured.
そして、発熱体３４の異常温度を図示されていない検知
手段が検知し、半導体３１を導電させると、該リレー３
０のコイル端子電圧は、およそゼロボルトになることで
瞬時に該リレー３０が開き、その後、Ｖｃｃから半導体
３１を通した電流により、電流ヒユーズ３２が溶断し、
該リレー３０の駆動回路が電気的に完全に開放されるこ
とにより、該リレー３０の接点は開放状態となる。When a detection means (not shown) detects an abnormal temperature of the heating element 34 and makes the semiconductor 31 conductive, the relay 3
When the coil terminal voltage of 0 becomes approximately zero volts, the relay 30 opens instantly, and then the current fuse 32 is blown by the current flowing from Vcc through the semiconductor 31.
By completely electrically opening the drive circuit of the relay 30, the contacts of the relay 30 become open.
以上の動作で、電源３３から発熱体３４への電力供給回
路が完全にしゃ断される。With the above operation, the power supply circuit from the power source 33 to the heating element 34 is completely cut off.
また前記電流ヒユーズ３２の代わりにヒユーズ抵抗器を
用いたものもある。Further, there is also one in which a fuse resistor is used instead of the current fuse 32.
［発明が解決しようとする課題］しかしながら、上記の従来の技術においては、電流ヒユ
ーズ３２では、検知手段の過渡的な動作による瞬時電流
が流れた場合には、溶断してしまうという問題点があり
、またヒユーズ抵抗器を用いた場合は、溶断時間が長い
ため、発熱体３４の異常事態が短時間で解除されてしま
うと、ヒユーズの溶断によるリレー駆動回路の完全な開
放か達成されないという問題点がある。[Problem to be Solved by the Invention] However, in the above-mentioned conventional technology, there is a problem that the current fuse 32 is blown out when an instantaneous current flows due to the transient operation of the detection means. In addition, when a fuse resistor is used, the blowing time is long, so if the abnormality of the heating element 34 is cleared in a short time, the relay drive circuit cannot be completely opened by blowing the fuse. There is.
本発明は、上記のような問題点を解決しようとするもの
である。すなわち、本発明は、過渡的動作による誤動作
の防止と、電力供給回路の完全な電気的しゃ断とを可能
にした発熱体電力制御装置を提供することを目的とする
ものである。The present invention attempts to solve the above problems. That is, an object of the present invention is to provide a heating element power control device that is capable of preventing malfunctions due to transient operations and completely electrically shutting off a power supply circuit.
［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、電力制御によっ
て発熱する発熱体と、該発熱体の温度異常時に電流をし
ゃ断する通電しゃ断手段およびこの通電しゃ断手段を制
御する際に、時間的遅延動作をする制御手段とを有する
発熱体電力制御装置において、前記制御手段に、時間的
保持手段が設けられているものとした。[Means for Solving the Problems] In order to achieve the above object, the present invention provides a heating element that generates heat through power control, an energization cutoff means that cuts off current when the temperature of the heating element is abnormal, and this energization cutoff means. In the heating element power control device having a control means that performs a time delay operation during control, the control means is provided with a time holding means.
［作 用コ本発明によれば、発熱体の温度異常時に電流をしゃ断す
る通電しゃ断手段およびこの通電しゃ断手段を制御する
際に、時間的遅延動作をする制御手段を有し、この制御
手段に、時間的保持手段が設けられているので、前記発
熱体の異常状態が解除された後にも、一定時間だけ通電
しゃ断手段に電力を供給することができ、したがって、
過渡的動作による誤動作の防止が可能となり、また電力
供給回路の完全な電気的しゃ断が可能となる。[Function] According to the present invention, there is provided an energization cutoff means that cuts off the current when the temperature of the heating element is abnormal, and a control means that performs a time delay operation when controlling the energization cutoff means. Since the time holding means is provided, power can be supplied to the energization cutoff means for a certain period of time even after the abnormal state of the heating element is released.
Malfunctions due to transient operations can be prevented, and the power supply circuit can be completely electrically cut off.
［実 施 例］第１図は本発明の第１実施例を示している。[Example]FIG. 1 shows a first embodiment of the invention.
同図において、１は発熱体の温度を検出するサーミスタ
、２は演算比較器、３は該演算比較器２に与える基準温
度、４は該演算比較器２の出力を保持させる保持回路、
５はリレーコイルおよびヒユーズ抵抗器を制御する半導
体スイッチ、６はヒユーズ抵抗器、７はリレーコイルに
電力を供給するリレーコイル用電源、８はリレーコイル
、９は発熱体、１０は該発熱体９に電力を供給する電源
、１１は該発熱体９と電源１０に直列に接続されるリレ
ー接点である。In the figure, 1 is a thermistor that detects the temperature of the heating element, 2 is an arithmetic comparator, 3 is a reference temperature given to the arithmetic comparator 2, and 4 is a holding circuit that holds the output of the arithmetic comparator 2.
5 is a semiconductor switch that controls a relay coil and a fuse resistor; 6 is a fuse resistor; 7 is a relay coil power source that supplies power to the relay coil; 8 is a relay coil; 9 is a heating element; 10 is the heating element 9 A power supply 11 is a relay contact connected in series to the heating element 9 and the power supply 10.
上記構成において、サーミスタ１で検出された温度と基
準温度とを演算比較器２で比較し、発熱体９の温度か基
準温度３よりも高くなれば、演算比較器２の出力が半導
体スイッチ５を制御し、半導体スイッチ５により、リレ
ーコイル８への電力供給は停止され、リレー接点１１が
開き、発熱体９への電力供給が停止され、温度は下降す
る。基準温度３は保持回路４により設定温度が低く変更
されるので、サーミスタ１による検出値が下がっても演
算比較器２の出力は、異常温度状態を保ち、半導体スイ
ッチ５からヒユーズ抵抗器６に入力され続け、やがてヒ
ユーズ抵抗器６は溶断され、リレーコイル８に供給され
る電力は完全に停止され、リレー接点１１は開放し続け
る。In the above configuration, the temperature detected by the thermistor 1 and the reference temperature are compared by the arithmetic comparator 2, and if the temperature of the heating element 9 is higher than the reference temperature 3, the output of the arithmetic comparator 2 switches the semiconductor switch 5. Under the control, the semiconductor switch 5 stops the power supply to the relay coil 8, opens the relay contact 11, stops the power supply to the heating element 9, and the temperature decreases. The reference temperature 3 is changed to a lower set temperature by the holding circuit 4, so even if the value detected by the thermistor 1 decreases, the output of the arithmetic comparator 2 maintains the abnormal temperature state and is input from the semiconductor switch 5 to the fuse resistor 6. Eventually, the fuse resistor 6 is blown out, the power supplied to the relay coil 8 is completely stopped, and the relay contacts 11 continue to be open.
以上の動作によって、電源１０から発熱体９への電力供
給は完全にしゃ断される。By the above operation, the power supply from the power source 10 to the heating element 9 is completely cut off.
第２図は第１図のしゃ断手段の制御装置を示している。FIG. 2 shows a control device for the cutoff means of FIG.
同図において、１２はサーミスタ、１３は発熱体、１４
はリレーコイルの接点、１５は本発明の要部であるリレ
ー制御回路、１６は該サーミスタ１２から出力値を解析
して電力制御の情報を与える温度検出回路、１７は該温
度検出回路１６からの情報により供給電力を制御する電
力制御回路、１８は該発熱体１３に電力を供給する電源
である。In the figure, 12 is a thermistor, 13 is a heating element, and 14
15 is a relay control circuit which is a main part of the present invention; 16 is a temperature detection circuit that analyzes the output value from the thermistor 12 and provides information for power control; and 17 is a contact point from the temperature detection circuit 16. A power control circuit 18 is a power source that supplies power to the heating element 13, which controls power supply based on information.
ここで、正常な状態では、温度検出回路１６と電力制御
回路１７により、発熱体１３への供給電力は制御される
が、ひとたび、温度検出回路１６あるいは電力制御回路
１７に異常が起こり、発熱体１３が異常温度になると、
リレー制御回路１５が働き、前記接点１４が開ぎ、電力
供給が停止される。In a normal state, the temperature detection circuit 16 and the power control circuit 17 control the power supplied to the heating element 13, but once an abnormality occurs in the temperature detection circuit 16 or the power control circuit 17, the power supplied to the heating element 13 is controlled. 13 becomes abnormal temperature,
The relay control circuit 15 is activated, the contact 14 is opened, and the power supply is stopped.
第３図は本発明の第２実施例を示している。FIG. 3 shows a second embodiment of the invention.
同図において、１９は発熱体の温度を検出するサーミス
タ、２０は演算比較器、２１は該演算比較器２０に与え
る基準温度、２２は該演算比較器２０の出力を保持する
保持回路、２３は該演算比較器２０の出力により制御さ
れる半導体スイッチ、２４はヒユーズ抵抗器、２５はリ
レーコイルに電力を供給するリレーコイル用電源、２６
はリレーコイル、２７は発熱体、２８は該発熱体２７に
電力を供給する電源、２９は該発熱体２７と電源２８に
直列に接続されるリレーの接点である。In the figure, 19 is a thermistor that detects the temperature of the heating element, 20 is an arithmetic comparator, 21 is a reference temperature given to the arithmetic comparator 20, 22 is a holding circuit that holds the output of the arithmetic comparator 20, and 23 is a A semiconductor switch controlled by the output of the arithmetic comparator 20, 24 a fuse resistor, 25 a relay coil power supply that supplies power to the relay coil, 26
27 is a relay coil, 27 is a heating element, 28 is a power source that supplies power to the heating element 27, and 29 is a contact point of a relay connected in series to the heating element 27 and the power source 28.
すなわち、前記第１実施例では、演算比較器の出力値を
、基準温度を変化させることで保持していたが、この第
２実施例では、記憶回路によって、入力値に関係なく、
異常時の出力値を保持するようにしたものである。That is, in the first embodiment, the output value of the arithmetic comparator is held by changing the reference temperature, but in the second embodiment, the output value of the arithmetic comparator is held by changing the reference temperature, but in the second embodiment, the output value of the arithmetic comparator is held by changing the reference temperature.
It is designed to hold the output value at the time of abnormality.
［発明の効果］以上説明したように本発明によれば、発熱体の温度異常
時に電流をしゃ断する通電しゃ断手段およびこの通電し
ゃ断手段を制御する際に、時間的遅延動作をする制御手
段を有し、この制御手段に、時間的保持手段が設けられ
ているので、前記発熱体の異常状態が解除された後にも
、一定時間だけ通電しゃ断手段に電力を供給することが
でき、したがフて、過渡的な現象による誤動作をなくす
ことが可能となり、また時間的遅延を持つ制御手段の確
実な動作完了を可能にするなどの効果を奏する。[Effects of the Invention] As explained above, according to the present invention, there is provided an energization cutoff means that cuts off the current when the temperature of the heating element is abnormal, and a control means that performs a time delay operation when controlling the energization cutoff means. However, since this control means is provided with a time holding means, even after the abnormal state of the heating element is released, power can be supplied to the energization cutoff means for a certain period of time. , it is possible to eliminate malfunctions due to transient phenomena, and it is also possible to ensure the completion of the operation of the control means having a time delay.
第１図は本発明の第１実施例を示した説明図、第２図は
第１図のしゃ断手段の制御装置の説明図、第３図は本発
明の第２実施例を示した説明図、第４図は従来の技術の
一例を示した説明図である。１・・・サーミスタ ２・・・演算比較器３・
・・基準温度 ４・・・保持回路５・・・半
導体スイッチ ６・・・ヒユーズ抵抗器７・・・リ
レーコイル用電源 ８・・・リレーコイル９・・・発熱
体 １０・・・電源１１・・・リレー接点
１３・・・発熱体１５・・・リレー制御回路
１６・・・温度検出回路１７・・・電力制御回路
２２・・・保持回路２４・・・ヒユーズ抵抗器
２７・・・発熱体他４名Fig. 1 is an explanatory diagram showing a first embodiment of the present invention, Fig. 2 is an explanatory diagram of a control device for the shutoff means in Fig. 1, and Fig. 3 is an explanatory diagram showing a second embodiment of the invention. , FIG. 4 is an explanatory diagram showing an example of a conventional technique. 1... Thermistor 2... Arithmetic comparator 3.
... Reference temperature 4 ... Holding circuit 5 ... Semiconductor switch 6 ... Fuse resistor 7 ... Power supply for relay coil 8 ... Relay coil 9 ... Heating element 10 ... Power supply 11. ...Relay contact 13...Heating element 15...Relay control circuit 16...Temperature detection circuit 17...Power control circuit 22...Holding circuit 24...Fuse resistor 27...Heating element 4 others
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2253590AJPH03226983A (en) | 1990-02-01 | 1990-02-01 | Heating element power control device |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2253590AJPH03226983A (en) | 1990-02-01 | 1990-02-01 | Heating element power control device |
| Publication Number | Publication Date |
|---|---|
| JPH03226983Atrue JPH03226983A (en) | 1991-10-07 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2253590APendingJPH03226983A (en) | 1990-02-01 | 1990-02-01 | Heating element power control device |
| Country | Link |
|---|---|
| JP (1) | JPH03226983A (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013038084A (en)* | 2006-04-05 | 2013-02-21 | Mks Instruments Inc | Multiple heater control system with expandable modular functionality |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013038084A (en)* | 2006-04-05 | 2013-02-21 | Mks Instruments Inc | Multiple heater control system with expandable modular functionality |
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