JPS63314582A - Fixing device - Google Patents

Fixing device

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Publication number
JPS63314582A
JPS63314582A JP15313187A JP15313187A JPS63314582A JP S63314582 A JPS63314582 A JP S63314582A JP 15313187 A JP15313187 A JP 15313187A JP 15313187 A JP15313187 A JP 15313187A JP S63314582 A JPS63314582 A JP S63314582A
Authority
JP
Japan
Prior art keywords
temperature
heat roller
roller
state
sheet
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
JP15313187A
Other languages
Japanese (ja)
Inventor
Masazumi Ito
正澄 伊藤
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.)
Minolta Co Ltd
Original Assignee
Minolta 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 Minolta Co Ltd filed Critical Minolta Co Ltd
Priority to JP15313187A priority Critical patent/JPS63314582A/en
Publication of JPS63314582A publication Critical patent/JPS63314582A/en
Pending legal-status Critical Current

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  • Fixing For Electrophotography (AREA)

Abstract

PURPOSE:To prolong a useful service life of a heat roller by pressing a separating claw formed by a shape memory alloy against the heat roller, only when the heat roller is below a fixing control temperature, and also, exceeds a set temperature being above a stand-by rotation start temperature. CONSTITUTION:A separating claw 10 is formed by a shape memory alloy which returns to its original shape at a martensite transformation temperature (storage temperature), and constituted so that at a temperature below the storage temperature, it holds the first state P1 that the tip is separated from a heat roller 3, and at the time of exceeding the storage temperature, it is transformed to the second state P2 that the tip is pressed against the surface of the heat roller 3. In this regard, the storage temperature is set in advance to a temperature heated by the influence from the heat roller 3, when the heat roller 3 is heated by a heater 4, it is above a fixing stand-by rotation start temperature, and also has become a separating claw press-contacting temperature being below a fixing control temperature. In such a way, a useful service life of the heat roller 3 can be extended.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は、粉体トナーを用いた複写機、プリンタ等の画
像形成装置に使用される定着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 fixing device used in image forming apparatuses such as copying machines and printers using powder toner.

(従来の技術) 従来、前記定着装置として、熱源(ヒータ)を有する熱
ローラと、該熱ローラに圧接する加圧ローラと有し、前
記熱ローラと加圧ローラとで未定着状態のトナー像を有
するシートを挾持搬送しつつ、前記シートに前記トナー
像を溶融定着するとともに、熱ローラにシートが巻き付
くのを防止するために、前記熱ローラの側部に分離爪を
付設し、これで定着後のシートを熱ローラから剥離して
分離するものが提供されている。
(Prior Art) Conventionally, the fixing device has a heat roller having a heat source (heater) and a pressure roller that is in pressure contact with the heat roller, and the toner image in an unfixed state is fixed by the heat roller and the pressure roller. In order to melt and fix the toner image on the sheet while holding and conveying the sheet having a heat roller, a separation claw is attached to the side of the heat roller in order to prevent the sheet from being wrapped around the heat roller. There has been provided a device that separates the fixed sheet by peeling it off from a heat roller.

(発明が解決しようとする問題点) しかしながら、前記分離爪は熱ローラに常時圧接してい
るため、分離爪の接触部において、熱ローラの損傷が著
しく、熱ローラの耐用寿命が短くなるという問題点を有
していた。
(Problems to be Solved by the Invention) However, since the separation claw is constantly in pressure contact with the heat roller, the heat roller is significantly damaged at the contact portion of the separation claw, resulting in a shortened service life of the heat roller. It had a point.

また、シートから熱ローラにオフセットしたトナーが分
離爪の先端に堆積し、これが夜間等の電源をオフした時
間帯に固化し、さらに、次に熱口−ラを回転を開始した
ときに前記固化したトナーの塊が分離爪の圧接面に入り
込み、熱ローラの表面を損傷するという問題点を有して
いた・ところが、分離爪は、その目的からして、常時熱
ローラに接触している必要はなく、定着装置がシートが
侵入してきた時だけ圧接していればよい。
In addition, toner offset from the sheet to the heat roller accumulates on the tip of the separating claw, and this solidifies when the power is turned off, such as at night. However, due to its purpose, the separation claw must be in constant contact with the heat roller. Instead, the fixing device only needs to press against the sheet when it enters the sheet.

そこで、本発明は、分離爪を、定着ローラが定着可能な
温度近くになると熱ローラに接触させ、それまでは非接
触状態に保持するようにしたものである。
Therefore, in the present invention, the separation claw is brought into contact with the heat roller when the fixing roller reaches a temperature close to that at which fixing can be performed, and is maintained in a non-contact state until then.

(問題点を解決するための手段) 本発明は前記[]的を達成するためになされたもので、
一実施例を示す第1.2図を参照して説明すると、熱源
(ヒータ)(4)を有する熱ローラ(3)と、該熱ロー
ラ(3)に圧接する加圧ローラ(5)とでシートを挾持
搬送しつつ、該シートに付着しているトナー像を前記シ
ートに溶融定着するとともに、前記熱ローラ(3)の側
部に分離爪(lO)を設け、該分離爪(10)で前記熱
ローラ(3)から前記シートを分離する定着装置におい
て、前記分離爪(10)を形状記憶合金で形成し、該分
離爪(10)を、前記熱ローラ(3)が、定着制御温度
(T1)以下で、かつ、定着予備回転開始温度(T、)
以上の設定温度[分離爪圧接温度(T、)]以下のとき
、前記熱ローラ(3)と非接触状態にある第1の状態(
Pυと、面記熱ローラ(3)が前記設定温度(’t’t
)以上のとき、前記熱ローラ(3)と接触する第2の状
e(p z)と、に変態しうるようにしたしのである。
(Means for solving the problems) The present invention has been made to achieve the above object,
Referring to FIG. 1.2 showing one embodiment, a heat roller (3) having a heat source (heater) (4) and a pressure roller (5) in pressure contact with the heat roller (3) will be described. While holding and conveying the sheet, the toner image attached to the sheet is melted and fixed onto the sheet, and a separating claw (10) is provided on the side of the heat roller (3), and the separating claw (10) In the fixing device that separates the sheet from the heat roller (3), the separation claw (10) is formed of a shape memory alloy, and the separation claw (10) is controlled by the heat roller (3) at a fixing control temperature ( T1) or below, and the fixing pre-rotation start temperature (T, )
When the temperature is below the set temperature [separation claw pressure contact temperature (T, )], the first state (
Pυ and the marking heat roller (3) are at the set temperature ('t't
) In the above case, it is possible to transform into the second state e(pz) in which it contacts the heat roller (3).

(実施例) 以下、本発明を、その一実施例を示す添付図面を参照し
て説明する。
(Example) Hereinafter, the present invention will be described with reference to the accompanying drawings showing one example thereof.

第1図は粉体現像型の複写機、プリンタ等における定着
装置を示し、(1)、(2)はケーシングで、これらケ
ーシング(1)、(2)で囲まれた空間内には熱ローラ
(3)、加圧ローラ(5)が収容されている。
Figure 1 shows a fixing device in a powder development type copying machine, printer, etc. (1) and (2) are casings, and in the space surrounded by these casings (1) and (2) is a heat roller. (3) and a pressure roller (5) are accommodated.

前記熟ローラ(3)は中央にヒータ(4)を有し、加圧
ローラ(5)は両端を軸受(8)(一方は図示せず)に
支持され、ホルダ(6)内に収容されているスプリング
(7)により熱ローラ(3)に圧接させである。
The ripening roller (3) has a heater (4) in the center, and the pressure roller (5) is supported at both ends by bearings (8) (one not shown) and is housed in a holder (6). The spring (7) is pressed against the heat roller (3).

熱ローラ(3)の上部には、サーミスタ測温体からなる
温度検出素子(9)が保持部材(8)を介してケーシン
グ(1)に取り付けてあり、前記温度検出素子(9)は
熱ローラ(3)の外周面に接触してその温度を検出する
ようにしである。
A temperature detection element (9) consisting of a thermistor temperature sensor is attached to the casing (1) via a holding member (8) on the upper part of the heat roller (3). (3) The temperature is detected by contacting the outer circumferential surface of the tube.

熱ローラ(3)の右側部には分離爪(10)が支軸(l
 I)を支点に回転可能に設けてあり、該分離爪(10
)はフレーム(12)に一端を取り付けたスプリング(
13)の他端が係止されて矢印(c)方向に付勢される
も、フレーム(12)のストッパ部(14)にて矢印(
c)方向への回転が規制されて、第1図に示す状態に位
置決めされている。
On the right side of the heat roller (3), a separating claw (10) is attached to a support shaft (l).
The separating claw (10
) is a spring (
13) Although the other end is locked and urged in the direction of arrow (c), the stopper part (14) of the frame (12)
c) Rotation in the direction is restricted, and the position is as shown in FIG. 1.

また、前記分離爪(lO)はマルテンサイト変態温度(
以下、「記憶温度」というX’r t’ )になると元
の形状に戻る形状記憶効果を発揮する形状記憶合金で形
成され、前記記憶温度(’rt’)以下の温度では、第
1図において実線で示すように、先端が熱ローラ(3)
から離間した第1の状態(Pυを保持し、記憶温度(T
2°)以上になると、第1図において点線で示すように
、先端が熱ローラ(3)の表面に圧接Vる第2の状態(
pt)に変態するようにしである。
Moreover, the separation claw (lO) has a martensitic transformation temperature (
It is formed of a shape memory alloy that exhibits a shape memory effect that returns to its original shape when it reaches the "memory temperature"(X'rt'), and at a temperature below the memory temperature ('rt'), As shown by the solid line, the tip is a heated roller (3)
The first state (Pυ is maintained and the memory temperature (T
2°), the tip enters a second state (V) where the tip is in pressure contact with the surface of the heat roller (3), as shown by the dotted line in Figure 1.
pt).

なお、前記記憶温度(’r t’ )は、第2図に示す
ように、熟ローラ(3)かヒータ(4)によって加熱さ
れ、定着予備回転開始温度(T3)以上で、かつ、定着
制御温度(T、)以下の分離爪圧接温度(T2)になっ
たとき、そのとき熱ローラ(3)からの影響により加熱
される温度に設定しである。
Note that, as shown in FIG. 2, the storage temperature ('r t') is heated by the maturing roller (3) or heater (4), is equal to or higher than the fixing preliminary rotation start temperature (T3), and is controlled by the fixing control. When the separation claw pressure contact temperature (T2) is lower than the temperature (T, ), the temperature is set to be heated by the influence of the heat roller (3).

以上の構成からなる定着装置では、本体電源がオフされ
ている状態では分離爪(10)は第1の状態(P、)に
ある。
In the fixing device having the above configuration, the separation claw (10) is in the first state (P,) when the main body power is turned off.

そして、電源が投入され、ヒータ(4)に通電されると
熱ローラ(3)は次第に温度上昇し、温度検出素子(9
)にて熱ローラ(3)の表面温度が予備回転開始温度(
T、)になったことが検出されると、図示しない駆動源
より熱ローラ(3)、加圧ローラ(5)が夫々矢印(a
) 、 (b)方向に回転し、熱ローラ(3)の熱が加
圧ローラ(5)に伝達され、熱ローラ(3)とともに加
圧ローラ(5)の温度が上昇する。
Then, when the power is turned on and the heater (4) is energized, the temperature of the heat roller (3) gradually rises, and the temperature detection element (9
), the surface temperature of the heat roller (3) reaches the pre-rotation start temperature (
When it is detected that the temperature has reached T, ), the heat roller (3) and the pressure roller (5) are moved by the arrow (a) from a drive source (not shown), respectively.
) and (b), the heat of the heat roller (3) is transferred to the pressure roller (5), and the temperature of the pressure roller (5) increases together with the heat roller (3).

なお、この状態ではまだ分離爪(10)は実線で示す第
1の状f3(Pl)を保持し、その先端は熱ローラ(3
)と非接触状態にある。
In this state, the separating claw (10) still maintains the first shape f3 (Pl) shown by the solid line, and its tip is connected to the heat roller (3).
) and are in a non-contact state.

そして、熱ローラ(3)の表面温度が分離爪圧接温度(
T2)になり、これに対応して分離爪(lO)が記憶温
度(Tt’ )になると、分離爪(lO)は記憶形状に
取り戻し点線状態に変態し、その先端を熱ローラ(3)
の表面に圧接する。
Then, the surface temperature of the heat roller (3) is the separating claw pressure contact temperature (
T2), and correspondingly, when the separating claw (lO) reaches the memorized temperature (Tt'), the separating claw (lO) returns to its memorized shape and transforms into the dotted state, and its tip is moved to the heated roller (3).
Press against the surface of the

このとき分離爪(10)の復元量が大きくても、その余
分な復元量はスプリング(13)に吸収され、分離爪(
10)は所定の圧力で熱ローラ(3)に圧接される。
At this time, even if the amount of restoration of the separation claw (10) is large, the extra amount of restoration is absorbed by the spring (13), and the separation claw (10) is absorbed by the spring (13).
10) is pressed against the heat roller (3) at a predetermined pressure.

熱ローラ(3)の表面温度がさらに上昇し、定着制御温
度(T1)に達っしたことが温度検出素子(9)により
検出されると、熱源(4)への通電が遮断され、以下温
度検出素子(9)からの情報を元に定着制御温度(T1
)を基窄として熱ローラ(3)の温度制御が行なわれる
When the temperature detection element (9) detects that the surface temperature of the heat roller (3) further increases and reaches the fixing control temperature (T1), the power supply to the heat source (4) is cut off, and the temperature decreases below. The fixing control temperature (T1) is determined based on the information from the detection element (9).
) is the basis for temperature control of the heat roller (3).

以上のごとく温度制御がなされている状態で定着動作が
可能となり、未定着状態のトナー像を上面に有するシー
トは矢印(d)方向から搬送され、熟ローラ(3)と加
圧ローラ(5)との回転に基づいて挾持搬送されつつ、
前記トナー像がシートに溶融定着される。
The fixing operation is enabled under temperature control as described above, and the sheet having an unfixed toner image on its upper surface is conveyed from the direction of arrow (d), and is moved between the ripening roller (3) and the pressure roller (5). While being held and conveyed based on the rotation with
The toner image is fused and fixed onto the sheet.

トナー像が定着されたシートは、第2の状態(点線状Q
Xp t)にある分離爪(lO)にて熱ローラ(3)の
表面から分離され、ガイド板(17)に沿って図示しな
い排紙部に排出される。
The sheet on which the toner image is fixed is in the second state (dotted line Q
The sheet is separated from the surface of the heat roller (3) by a separation claw (lO) located at Xp t), and is discharged to a paper discharge section (not shown) along a guide plate (17).

なお、前記トナ一定着時に熱ローラ(3)にオフセット
されたトナーの一部は、分離爪(lO)の先端部に堆積
する。しかし、熱ローラ(3)が温度制御されている状
態ではトナーは軟化しており、これが熱ローラ(3)の
表面を損傷するようなことはない。
A portion of the toner offset by the heat roller (3) when the toner is fixed is deposited on the tip of the separating claw (lO). However, when the temperature of the heat roller (3) is controlled, the toner is softened, and this does not damage the surface of the heat roller (3).

本体の電源が遮断され、熱ローラ(3)の表面温度が分
離爪圧接温度(T、)以下になると、これに対応して分
離爪(lO)も第2の状態(P、)から第1の状態(P
 、)に変態し、さらに、常温状態に低下すると、前記
分離爪(lO)の先端に堆積したトナーが冷えて固化す
る。
When the power to the main body is cut off and the surface temperature of the heat roller (3) becomes lower than the separation claw pressure contact temperature (T,), the separation claw (lO) also changes from the second state (P, ) to the first state. state (P
), and when the temperature is further lowered to room temperature, the toner deposited on the tip of the separating claw (lO) cools and solidifies.

そして、再び本体の電源が投入されて熱ローラ(3)の
表面温度が上昇していくと、これにつれて分離爪(10
)に付着したトナーは熱ローラ(3)の熱影響を受けて
軟化する。そして、熱ローラ(3)の表面温度が分離爪
圧接温度(T、)になり、分離爪(10)が第2の状Q
(p t)に変化して熱ローラ(3)の表面に圧接して
も、この時点では前述したように、すでにトナーは軟化
しているため、トナーによって熱ローラ(3)の表面が
損傷するようなことはない。
Then, when the power of the main body is turned on again and the surface temperature of the heat roller (3) rises, the separation claw (10
) is softened by the heat of the heat roller (3). Then, the surface temperature of the heat roller (3) becomes the separating claw pressure contact temperature (T, ), and the separating claw (10) reaches the second state Q.
Even if the toner changes to (p t) and comes into contact with the surface of the heat roller (3), the surface of the heat roller (3) will be damaged by the toner because at this point the toner has already softened as described above. There is no such thing.

(発明の効果) 以上の説明で明らかなように、本発明にかかる定着装置
では、分離爪を形状記憶合金で形成し、熱ローラが、定
着制御温度以下で、かつ、予備回転開始温度以上の設定
温度以上にあるときだけ分離爪が然ローラに圧接するよ
うにしている。
(Effects of the Invention) As is clear from the above description, in the fixing device according to the present invention, the separating claw is formed of a shape memory alloy, and the heat roller is heated at a temperature below the fixing control temperature and above the pre-rotation start temperature. The separating claws come into pressure contact with the roller only when the temperature is higher than the set temperature.

このため、分離爪が熱ローラに接触する頻度が少なくな
り、熱ローラの表面を損傷する度合も少なく、熱ローラ
の耐用寿命を長く保つことかできまた、機械的、電気的
手段によることなく、単に、分離爪を形状記憶合金で形
成することにより分離爪の状態を変えるようにしている
ため、構成が簡単である。
For this reason, the separation claws come into contact with the heat roller less frequently, the surface of the heat roller is less likely to be damaged, and the useful life of the heat roller can be maintained for a long time. The configuration is simple because the state of the separating claws is changed simply by forming the separating claws from a shape memory alloy.

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

第1図は定着装置の断面図、第2図は熱ローラの表面温
度状態を示す図である。 1.2・・・ケーシング、3・・・熱ローラ、4・・・
熱源、5・・・加圧ローラ、   9・・・温度検出素
子、10・・・分離爪、    P、・・・第1の状態
、P、・・・第2の状態、  T1・・・定着制御温度
、T、・・・分離爪圧接温度、T、゛・・・記憶温度、
T3・・・予備回転開始温度。
FIG. 1 is a sectional view of the fixing device, and FIG. 2 is a diagram showing the surface temperature state of the heat roller. 1.2...Casing, 3...Heat roller, 4...
Heat source, 5... Pressure roller, 9... Temperature detection element, 10... Separation claw, P,... First state, P,... Second state, T1... Fixing Control temperature, T,... Separation claw pressure contact temperature, T, ゛... Memory temperature,
T3...Preliminary rotation start temperature.

Claims (1)

【特許請求の範囲】[Claims] (1)熱源を有する熱ローラと、該熱ローラに圧接する
加圧ローラとでシートを挾持搬送しつつ、該シートに付
着しているトナー像を前記シートに溶融定着するととも
に、前記熱ローラの側部に分離爪を設け、該分離爪で前
記熱ローラから前記シートを分離する定着装置において
、前記分離爪を形状記憶合金で形成し、該分離爪を、前
記熱ローラが、定着制御温度以下で、かつ、定着予備回
転開始温度以上の設定温度以下のとき、前記熱ローラと
非接触状態にある第1の状態と、前記熱ローラが前記設
定温度以上のとき、前記熱ローラと接触する第2の状態
と、に変態しうるようにしたことを特徴とする定着装置
(1) A sheet is held and conveyed between a heat roller having a heat source and a pressure roller that is in pressure contact with the heat roller, and the toner image attached to the sheet is melted and fixed on the sheet. In a fixing device that includes a separation claw on a side and separates the sheet from the heat roller with the separation claw, the separation claw is formed of a shape memory alloy, and the separation claw is set at a temperature below the fixing control temperature of the heat roller. and a first state in which the heat roller is in a non-contact state when the temperature is lower than or equal to the preset fixing rotation start temperature, and a first state in which the heat roller is in contact with the heat roller when the temperature is higher than the preset temperature. 2. A fixing device characterized by being able to transform into the following states.
JP15313187A 1987-06-17 1987-06-17 Fixing device Pending JPS63314582A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP15313187A JPS63314582A (en) 1987-06-17 1987-06-17 Fixing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP15313187A JPS63314582A (en) 1987-06-17 1987-06-17 Fixing device

Publications (1)

Publication Number Publication Date
JPS63314582A true JPS63314582A (en) 1988-12-22

Family

ID=15555667

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15313187A Pending JPS63314582A (en) 1987-06-17 1987-06-17 Fixing device

Country Status (1)

Country Link
JP (1) JPS63314582A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6640062B2 (en) 2000-02-29 2003-10-28 Sharp Kabushiki Kaisha Toner image fixing device provided with a sheet separating portion

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6640062B2 (en) 2000-02-29 2003-10-28 Sharp Kabushiki Kaisha Toner image fixing device provided with a sheet separating portion

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