JPH04204984A - Heater - Google Patents

Abstract

PURPOSE:To effectively correct the curling of a recording material by providing a recording material separating and guiding member which transports and guides the recording material from a press contact nip part while stripping this material from a press roller. CONSTITUTION:The recording material P is transported along a recording material guide surface 33a of an upward grade of the recording material separating and guiding member 33 disposed on the recording material outlet side of the press contact nip part N after the recording material emerges from the nip part N. The end 33b on the downstream side in the recording material transporting direction of the guide surface 33a exists in the position higher than the nip part N in such a case and, therefore, the recording paper P emerging from the nip part N is forcibly curved in the direction opposite from the curling direction of the recording material P between the nip part N and the end 33b and is successively transported in this state while climbing on the guide surface 33a. Consequently, the curling of the recording material P is corrected by the force reverse curling treatment reverse from the curling direction.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention involves bringing a recording material into close contact with a heating body through a heat-resistant film, moving the heating body and the heat-resistant film relative to each other, and dissipating the heat of the heating body. A method of applying the film to the recording material through the adhesive film (
This invention relates to a heating device using a film heating method.

This device is an image heating fixing device in an image forming apparatus such as an electrophotographic copying machine, a printer, or a fax machine, that is, it is made of heat-melting resin, etc., by an appropriate image forming process means such as electrophotography, electrostatic recording, magnetic recording, etc. Unfixed toner that corresponds to the desired image information and is formed using toner on the surface of a recording material (transfer material sheet, electrofax sheet, electrostatic recording sheet, printing paper, etc.) using an indirect (transfer) method or a direct method. An image heat fixing device that heats and fixes an image as a permanently fixed image on the surface of a recording material carrying the image; a device that heats the recording material carrying the image to modify its surface properties (such as gloss); It can be used for devices that perform temporary attachment treatment.

(Background Art) Conventional 1 For example, a recording material heating device for heat fixing an image uses a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and in pressure contact with the heating roller. ,
A heated roller system that heats the recording material while nipping and conveying it is often used.

In addition, various other methods are known, such as a flash heating method, an oven heating method, a hot plate heating method, a belt heating method, and a high frequency heating method.

On the other hand, the present applicant has proposed a film heating type heating device as described above in, for example, Japanese Unexamined Patent Publication No. 63-313182.

The heating body is fixedly supported, the heat-resistant film (or sheet) is conveyed (moved and driven) while being in pressure contact with the heating body, and the recording material is pressed into close contact with the heating body through the film layer. This device has a system and structure that heats and fixes an unfixed image formed and carried on the recording material surface onto the recording material surface by applying heat from a heating body to the recording material through a film.

More specifically, it includes a thin heat-resistant film, a means for moving the film, a heating element fixedly supported on one side of the film with the film inside, and the heating element on the other side. A pressure member is disposed facing the heating body and brings the image bearing surface of the S recording material into close contact with the heating body through the film, and the film is pressed against the film at least when fixing the image. The recording material to be image-fixed is conveyed and introduced between the film and the pressure member, and the film is moved in the forward direction at a substantially concave speed, and the film is formed by pressure contact between the heating body and the pressure member with the film in between. The image-bearing surface of the recording material is heated by the heating body through the film, thereby imparting thermal energy to the developed image (unfixed toner image). Soften and melt.

Next, the heating means/device is basically to separate the film and the recording material after passing through the fixing section at a separation point.

This kind of film heating type equipment uses a heating element with a fast temperature rise and a thin film, which makes it possible to shorten wait time (quick start) and solve various drawbacks of conventional equipment. It has advantages.

A schematic configuration of an example of an image heat fixing device of this type using an endless film as a heat-resistant film is shown in the 11th [ffl].

51 is an endless belt-shaped heat-resistant film (hereinafter referred to as fixing film or simply film), which includes a drive roller 52 on the left, a driven roller 53 on the right, and a film between the drive roller 52 and the driven roller 53. The three members 52 and 52 of the low heat capacity linear heating element 19 arranged below are substantially parallel to each other.
The suspension is installed between 53 and 19.

The fixing film 51 is rotated clockwise at a predetermined circumferential speed as the driving roller 52 rotates clockwise, that is, as a heated material carrying an unfixed toner image Ta conveyed from an image forming section (not shown) on its upper surface. The recording material sheet P is rotated at approximately the same peripheral speed as the conveyance speed (process speed) of the recording material sheet P.

Reference numeral 55 denotes a pressure roller as a pressure member, which holds the downward film portion of the endless belt-shaped fixing film 51 between it and the heating body 19, and attaches an unillustrated attachment to the lower surface of the heating body. The recording material sheet P is pressed into contact with the recording material sheet P by a force means, and rotates in a direction opposite to a forward direction in the conveying direction of the recording material sheet P.

The heating body 19 is a low heat capacity linear heating body whose length is in the direction intersecting the plane movement direction of the film 51 (width direction of the film), and includes a heater substrate (base material) 19a and a heating element (current-carrying heating resistor) 19b. - It is made of a surface protection layer 19c, etc., and is fixedly supported by being attached to a support body 80 via a heat insulating member 20.

A recording material sheet P carrying an unfixed toner image Ta on its upper surface, conveyed from an image forming section (not shown), is guided by a guide 81 to a pressure contact portion N (pressure nip portion) between the heating body 19 and the pressure roller 55. The unfixed toner image surface enters between the fixing film 51 and the pressure roller 55, and the unfixed toner image surface comes into close contact with the lower surface of the fixing film 51, which is being rotated in the same direction at the same speed as the conveyance speed of the recording material P. Then, it passes between the mutual pressure contact portion N between the heating body 19 and the pressure roller 55 in an overlapping state together with the film.

The heating body 19 is electrically heated at a predetermined timing, and the thermal energy on the heating body 19 side is transmitted to the recording material sheet P side that is in close contact with the film via the film 51, and the toner image Ta passes through the pressure contact portion N. During this process, it is heated and becomes a softened and melted image Tb.

The rotating direction of the fixing film 51 is changed at an acute angle θ at an edge portion S of the heat insulating member 20 having a large curvature. Therefore, the recording material sheet P conveyed through the pressure contact part N in a state overlapping with the fixing film 51 passes through the fixing film 5 at the edge part S. curvature separation from l,
By the time the toner reaches the paper ejection section, the toner has been sufficiently cooled and solidified and is completely fixed on the recording material sheet P.

The fixing film 51 is not limited to an endless belt shape.
As shown in the example in FIG. 2, the fixing film 51 with an end wound in a roll around the feed-out shaft 82 is passed between the heating body 19 and the pressure roller 55, and is locked to the take-up shaft 83. It is also possible to adopt a configuration (film winding retype) in which the recording material sheet P runs at the same speed as the conveyance speed of the recording material sheet P from the side toward the winding shaft 83 side.

(Problems to be Solved by the Invention) In this type of heating device, the recording material introduced into the device and subjected to heat treatment has a large convex curl on the side facing the heating body (the surface side of the recording material). There was a problem that more or less particles were formed.

That is, as shown in FIG. 13, the heat-resistant film 51 and the pressure roller 55 at the pressure nip portion N between the film sliding plane of the heating body 19 and the pressure roller 55 formed with the heat-resistant film 51 sandwiched therebetween. The recording material P introduced between the heating element 19 has a convex curl (the surface side of the recording material) on the side opposite to the heating element 19 (the surface side of the recording material A downward curl) is formed. This curling is caused by the shape of the pressure nip N (the member on one side of the pressure nip N is heated by the heating element 1).
This is thought to be due to the heating direction and the fact that the other side member is the circular arc surface of the pressure roller 55 which is in pressure contact with the film sliding plane portion of No. 9.

Formation of curls as described above on the recording material P that has passed through the heating device may cause sheet jams during the sheet path from the heating device to the ejecting section, and may reduce the handling of the output recording material. This may cause a sheet jam to occur in the sheet path in the sorter when the recording material is introduced into the sorter, or the recording material on which one side or the first image has been formed may be introduced into the re-feed sheet path in double-sided or multiple image forming mode. If this occurs, it may cause a sheet jam in the sheet path, a loading failure on the intermediate tray, a re-feeding failure, etc.

Undesirable.

Even if the recording material is curled by passing through the pressure nip section of the heating device, the present invention has a simple means structure to remove the curl immediately after the recording material passes through the pressure nip section. By effectively straightening the sheet (removal of curls and decurling), problems such as sheet jamming as described above are prevented from occurring.

(Means for Solving the Problems) The present invention comprises: a fixedly supported heating body; a heat-resistant film that slides in close contact with a film sliding plane portion of the heating body; The moving plane part has a pressure roller that presses the heat-resistant film between them, and the heat-resistant film and the pressure roller are in a pressure-contact nip area between the heating body and the pressure roller, which are formed by sandwiching the heat-resistant film. It is a heating device that applies heat from a heating body to the recording material through the heat-resistant film at the pressure-welding nip by introducing a recording material between the two and moving it through the pressure-welding 277 portion together with the heat-resistant film, and the pressure-welding nip It is placed on the recording material exit side of the unit.

It has a recording material separation guide member that conveys and guides the recording material that has passed through the pressure nip while peeling it from the pressure roller, and the recording material guide surface of the recording material separation guide member faces toward the downstream side in the recording material conveyance direction. The heating device is characterized in that the surface is an upward slope, and the downstream end of the recording material guide surface in the recording material conveying direction is located at a higher position than the pressure nip portion position.

Further, in the heating device having the above-mentioned structure, the present invention provides an upward inclination angle A of the recording material guide surface of the recording material separation guide member of 10.
This is a heating device whose # characteristic is that "≦A≦30."

(Function) That is, as specifically shown in FIG. 8, even if the recording material P is curled (indicated by a two-dot chain line) by passing through the pressure nip N of the heating device, the recording material After exiting the pressure nip N, the recording material separation guide member 33 disposed as described above on the recording material exit side of the pressure nip N has an upwardly inclined recording material guide surface 33a, that is, on the downstream side in the recording material conveyance direction. In this case, the recording material guide surface 33a is conveyed while going up the inclined guide surface 33a.
is located at a higher position than the pressure welding nip N position,
The portion of the recording material that has exited the pressure nip is forcibly curved in the opposite direction to the curl direction of the recording material P between the pressure nip N and the higher end 33b of the recording material guide surface 33a (reverse warping). In this state, the paper is conveyed while climbing up the inclined guide surface 33a.

As a result, the recording material is corrected by the above-mentioned forced reverse warping in the opposite direction to the curling direction. This curl correction can be effectively carried out because the recording material P has just passed through the two pressing knees and still has sufficient heat.

The upward f1M angle A of the recording material guide surface 33a of the recording material separation guide member 33 is preferably set in the range of 10@≦A≦30'''; when A<10'', the curl correction effect is insufficient for practical use. , A>30'', the conveyance resistance of the recording material becomes large, which may impede conveyance.

Note that if the end 33b of the recording material guide surface 33 on the downstream side in the recording material conveying direction is lower than the pressure nip portion N position, there is actually no reverse warping of the recording material P, and no curl correction effect can be obtained.

/ (Example) The drawing shows an apparatus according to an embodiment of the present invention (image heat fixing apparatus 100).
).

(1) Overall schematic structure of the device 100 FIG. 1 is a cross-sectional view of the device 100, FIG. 2 is a longitudinal sectional view, FIGS. 3 and 4 are right and left side views of the device, and FIG. is an exploded perspective view of main parts.

1 is a horizontally elongated device frame (bottom plate) made of sheet metal and has an upward channel (groove) cross section; 2 and 3 are a left side wall plate and a right side wall that are integrally provided at both left and right ends of this IT frame l. A plate 4 is an upper cover of the device, which is fitted between the upper ends of the left and right side wall plates 2 and 3, and its left and right ends are fixed to the left and right side wall plates 2 and 3 with screws 5, respectively. It can be removed by loosening and removing the screws 5.

6 and 7 are vertical notched elongated holes formed symmetrically in the substantially central portions of the left and right side wall plates 2 and 3, and 8 and 9 are elongated holes 6 and 7, respectively.
A pair of left and right bearing members are fitted and engaged with the lower end portions of the bearing members.

Reference numeral 10 denotes a film pressure roller (pressure contact roller) as a rotating body that sandwiches the film with a heating body to be described later to form a nip portion and drives the film.

The back-up roller is composed of a central shaft 11 and a roller portion 12 made of a rubber elastic material with good mold releasability such as silicone rubber, which is sheathed around this shaft. The members 8 and 9 are rotatably supported by bearings.

Reference numeral 13 denotes a horizontally elongated stay made of sheet metal, which serves as an inner surface guide member for a film 21 (described later) and a supporting/reinforcing member for a heating body 19-insulating member 20 (described later).

This stay 13 includes a horizontally long flat bottom part 14, and a front wall plate 15 and a rear wall plate 16 each having an outwardly curved cross section and extending in series from both longitudinal sides of the bottom part 14.
It has a pair of left and right horizontally projecting lug parts 17-18 that project outward from both left and right ends of the bottom surface part 14, respectively.

Reference numeral 19 denotes a horizontally long low heat capacity linear heating body having a structure (FIG. 9) to be described later, and is mounted and supported by a horizontally long heat insulating member 20, and the heat insulating member 20 is placed with the heating body 19 side facing downward. The stay 13 is integrally attached and supported in parallel to the lower surface of the oblong bottom surface portion 14.

21 is an endless heat-resistant film, heating element 19
It is externally fitted onto the stay 13 including the φ heat insulating member 20. The inner circumferential length of this endless heat-resistant film 21 and the outer circumferential length of the stay 13 including the heating element 19φ heat insulating member 20 are larger than the film 21 by, for example, 3 mm. The circumferential length of the stay 13 including the stay 20 is loosely fitted around the stay 13 with a margin.

22 and 23 connect the film 21 to the heating body 19φ insulating member 20
These are a pair of left and right film end regulating flange members that are fitted onto the stay 13 containing the stay 13 and then fitted onto and supported by the horizontally projecting lug portions 17 and 18 at the left and right ends of the stay 13.

The distance between the inner surfaces 22a and 23a of the flanges of the pair of left and right flange members 22-23 is set to be slightly larger than the width of the film 21.

24 and 25 are the pair of left and right flange members 22 and 23.
This is a horizontally extending lug portion that protrudes outward from the outer surface of the stay 13 side.
The left and right flange members 22 and 18 are fully fitted into insertion holes provided within the wall thickness of the horizontally extending lug portions 24 and 25 of the flange members 22 and 23, respectively.
I firmly support 23.

To assemble the device, remove the upper cover 4 from between the left and right side wall plates 2 and 3, and attach the film pressure roller 10 with the left and right bearing members 8 and 9 fitted in advance to the left and right ends of the shaft 11.
The left and right bearing members 8 and 9 are fitted into the vertical notched long holes 6φ7 of the left and right side wall plates 2 and 3 from the open upper end, and the pressure roller 10 is inserted between the left and right side wall plates 2 and 3. The bearing members 8 and 9 are lowered to the position where they are stopped at the lower ends of the elongated holes 6 and 7 (drop-in type).

Next, the intermediate assembly, in which the stay 13, the heating body 19, the heat insulating member 20, the film 21, and the left and right flange members 22 and 23 are assembled in advance in the relationship shown in the figure, is placed with the heating body 19 facing downward and the heat insulating member The left and right outward protruding ends of 20 and the horizontally extending lug portions 2 of the left and right flange members 22 and 23
The left and right side wall plates 2 and 3 are assembled by fitting and engaging the 4φ25 holes into the vertical notched elongated holes 6 and 7 of the left and right side wall plates 2φ3 from the upper end openings, respectively.
(J-insertion type) in which the heating element 19 facing downward hits the upper surface of the previously assembled pressure roller 10 with the film 21 in between and lowers the receiver until it is stopped.

Coil springs 26 and 27 are provided on the upper surfaces of the lugs on the lugs 24 and 25 of the left and right flange members 22@23, respectively, which protrude through the elongated holes 6 and 7 on the outside of the left and right side wall plates 2 and 3. The upper cover 4 is positioned vertically with support protrusions, and the outer projecting lug portions 28 and 29 provided on the left and right end sides of the upper cover 4 are attached to the upper ends of the coil springs 26-27 set above. While compressing the coil springs 26 and 27 between the lug parts 24, 28, 25, and 29, fit them to the specified position between the upper ends of the left and right side wall plates 2 and 3, and tighten the left and right screws 5. Fix it between the side wall plates 2 and 3.

As a result, the stay 13, heating element 19, heat insulating member 20, film 21.
The entire left and right flange members 22 and 23 were pressed downward, and the heating body 19 and the m-pressure roller 10 were brought into contact with each other approximately equally in the longitudinal direction with the film 21 in between, for example, with a total contact pressure of 4 to 7 kg. held in state.

Reference numerals 30 and 31 designate connectors for supplying power to the heating body 19, which are fitted to both left and right ends of the heat insulating member 20 that protrudes from the outside of the left and right side wall plates 2 and 3 through long holes 6 and 7.

32 is a device! This is a heated material inlet guide installed on the front wall of the 7-frame L. 7) is guided toward the nip portion (heat fixing portion) N between the heating body 19 and the pressure roller 10, which are in pressure contact with each other with the film 21 in between, between the film 21 and the pressure roller 10.

Reference numeral 33 denotes a recording material separation guide member attached to the rear wall of the apparatus frame l, which guides the recording material sheet that has passed through the edge portion N to the nip between the lower discharge roller 34 and the upper pinch roller 38. I will guide you to the department.

The recording material separation guide member 33 has an upstream end 33c in the recording material conveying direction close to the outer surface of the pressure roller 10.
Even if the recording material P exiting the nip portion N is conveyed in close contact with the outer surface of the pressure roller 10, the leading edge of the recording material P is separated from the surface of the roller 10 by the edge portion of the recording material separation guide member 33c for recording. The recording material P is guided to the upper surface 33 a of the material separation guide member 33 to prevent the recording material P from being caught up in the roller 10 .

Further, as shown in FIG. 8, the recording material separation guide member 33 has a recording material guide surface 33a that is inclined upwardly toward the downstream side in the recording material conveyance direction (10°≦incline angle A≦30°), and An end 33b of the recording material guide surface 33a on the downstream side in the recording material conveying direction is located at a position higher than the nip portion N position.

The discharge roller 34 has both left and right ends of its shaft 35 rotatably supported between bearings 36 and 37 provided on the left and right side wall plates 2 and 3. The pinch roller 38 has a hook portion 40 formed by bending a part of the rear wall of the upper cover 4 inward at its shaft 39.
The receiver is inserted into the container and brought into contact with the upper surface of the discharge roller 34 by its own weight and the pressure spring 41. The pinch roller 38 rotates as the discharge roller 34 rotates.

G1 is a roller shaft 11 that projects outward from the right side wall plate 3.
It's stuck on the right side of the page! The $1 gear, G3, is a third gear fixed to the right end of the discharge roller shaft 35 which also projects outward from the right side wall plate 3, and G2 is a relay gear provided pivotably on the outer surface of the right side wall plate 3. The second gear is the first gear G mentioned above.
1 and third gear G3.

The first gear G1 receives a driving force from a driving gear GO of a drive source mechanism (not shown), and the pressure roller 10 is rotationally driven in the counterclockwise direction in FIG. It is transmitted to the third gear G3 via the second gear G2, and the discharge roller 34 is also rotationally driven in the counterclockwise direction in FIG.

(2) Operation When the endless heat-resistant film 21 is not driven, the remaining part of the endless heat-resistant film 21 except for the part sandwiched between the nip N between the heating body 19 and the pressure roller 10 is shown in the enlarged view of the main part in FIG. Most of the entire circumference is tension-free.

When the drive is transmitted from the drive gear GO of the drive source mechanism to the first gear Gl and the pressure roller 10 is rotationally driven in the counterclockwise direction in FIG. A feeding movement force is applied due to the frictional force with the pressure roller 10, and the endless heat-resistant film 21 moves in the clockwise direction A while the inner surface of the film slides on the surface of the heating body 19 at approximately the same speed as the peripheral rotational speed of the pressure roller 10. It is driven to rotate and move.

In this driving state of the film 21, a pulling force f acts on the part of the film that is closer to the film rotation force than the nip N, so that the film 21 is moved further than the nip N as shown by the solid line in FIG. It is provided upstream in the film rotation direction and comes into contact with the inner surface guide portion of the film near the nip portion, that is, approximately the lower half surface portion of the outwardly curved front plate 15 serving as the inner surface guide of the film of the stay 13 on which the film 21 is externally fitted. It rotates while causing sliding motion.

As a result, the rotating film 21 rotates with tension acting on the film portion B from the starting point 0 of the contact sliding portion with the front plate 15 to the nip portion N on the downstream side in the film rotation direction. As a result, wrinkles are prevented from forming at least on the film portion surface, that is, on the film portion surface B near the recording material sheet entrance side of the nip portion N, and on the film portion of the nip portion N, due to the action of the tension described above.

Then, while the film is driven and the heating element 19 is energized, the recording material sheet P carrying the unfixed toner image Ta as the material to be heated is rotated through the nip portion N while being guided by the entrance guide 32. Dynamic film 21 and pressure roller 10
When the recording material sheet P is introduced with the image bearing surface facing upward,
passes through the nip N together with the film 21 in close contact with the surface of the film 21, and in the process of moving and passing, the thermal energy of the heating element 19 that is in contact with the inner surface of the film at the nip N causes the film to The toner image Ta applied to the recording material sheet P through the toner image becomes a softened and fused image Tb.

The recording material sheet (P) that has passed through the nip portion N is separated from the film 21 surface in a state where the toner temperature is higher than the glass transition point, is guided by the exit guide 33 between the discharge roller 34 and the pinch roller 38, and is sent out of the apparatus. It will be done. Recording material sheet) P
The softened φ fused toner image Tb is cooled, solidified into an image Te, and fixed while the molten toner image Tb exits the nip portion N, leaves the surface of the film 21, and reaches the discharge roller 34.

Furthermore, even if the recording material P that has exited the nip portion N is conveyed in close contact with the outer surface of the pressure roller 10, the recording material separation guide member 3
No. 3, the edge portion of the approaching end 33c to the pressure roller 10 separates the recording material from the surface of the roller 10 and guides it to the upper surface 33a of the recording material separation guide member 33, so that it does not wrap around the outer peripheral surface of the roller 10.

As explained in the above (effect) section, the recording material P that has left the nip portion N is curled in the opposite direction to the curling direction in the process of being transported and passed through the guide surface 33a, thereby preventing uncurling. It will be done.

As mentioned above, the recording material sheet P introduced into the nip part N is under tension and always adheres to the unwrinkled film part surface and moves through the nip part N together with the film 21, so that the wrinkled film is not produced. Occurrence of heating unevenness and fixing unevenness due to a situation where the liquid passes through the nip part N,
No creases on the film surface.

The film 21 has a part N of its total circumference both when being driven and when being driven.
Or, since tension is applied only to B-N, that is, when not being driven (Fig. W46), most of the remaining 1 minute of the entire circumference of the film 21 excluding the nip portion N is tension-free, and even when being driven, the film 21 is tension-free. Tension acts only on part N and film part B in the vicinity of the recording material sheet entrance side of the nip part N, and most of the remaining part, almost the entire circumference, is tension-free, and the circumference is short overall. Since film can be used, the drive torque required to drive the film is small, and the structure of the film device, parts, and drive system can be simplified, downsized, and lowered in cost.

Also, when the film 21 is not driven (FIG. 6) and when it is driven (FIG. 7),
2), tension is applied to the film 21 only on part N or B@N of the entire circumference as described above, so when the film is driven, the film 21 is placed on one side Q in the film width direction (Fig. 2) or Even if a shift toward the other side R occurs, the shift force is small.

Therefore, the film 21 shifts Q or R, and its left edge becomes the straddle inner surface 22a as the film end regulating surface of the left flange member 22, or its right edge becomes the right flange member 23.
Even if the film is pressed against the inner surface 23a of the straddle seat, the film's biasing force is small, so the rigidity of the film sufficiently overcomes the biasing force, and the edge of the film does not buckle or break. As the deviation regulating means is sufficient as the simple flange members 22 and 23 as in the device of this embodiment, the device configuration can be simplified, downsized, and lowered in cost in this respect as well, resulting in an inexpensive and highly reliable device. can.

In addition to the flange members 22 and 23 in the case of the device of this embodiment, for example, a rib made of heat-resistant resin is provided at the end of the film 21 in the circumferential direction of the endless film as the film deviation regulating means, and this rib is regulated. Good too.

Furthermore, as the film 21 to be used, the rigidity can be reduced by the reduction in the biasing force as described above, so that the quick start performance of the device can be improved by using a film that is thinner and has a smaller heat capacity.

(3) Film 21 In order to reduce the heat capacity of the film 21 and improve quick start performance, the film thickness T of the film 21 is set to a total thickness of 10
A single layer or composite layer film having heat resistance, mold releasability, strength, durability, etc. of 0 gm or less, preferably 40 pm or less, and 20 pm or more can be used.

For example, polyimide polyetherimide (PEI)
Polyether sulfone (PES) ・Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) ・Polyether ether ketone (PEEK)
)-polyparabanic acid (PPA), or PTFE (tetrafluoroethylene resin)/P at least on the image contact side of a composite layer film, such as a 20 pm thick polyimide film.
10jL of mold releasable coat made by adding conductive materials (carbon black, graphite, conductive whiskers, etc.) to fluororesin silicone resin such as AF-FEP.
For example, it is applied to a thickness of m.

(4) Heating body 19 FIGS. 9(A) and 9(B) are partially cutaway planes of the surface side (the side facing the heat-resistant film 21) of the heating body 19 attached to the heat insulating member 20, respectively. and an enlarged cross-sectional view.

The substrate 19a is a heat-resistant, electrically insulating, low heat capacity, high heat conductive member, and has a diameter of 4 f, a thickness of 1 mm, a radius of 6 mm,
It is a 240 mm long alumina substrate.

The heating element 19b is arranged along the central part of the surface of the substrate 19a, for example, Ag/Pd (silver), Ta
2 Electrically resistive material such as N or RuO2 with a thickness of about 10 pm.
It is coated in the form of a line or strip with a width of 1 to 3 mm by screen printing or the like.

Conductive patterns 19d are formed as first and second power feeding electrodes on the surface of the substrate on both longitudinal ends of the heating element 19b.
-19e are electrically connected to the ends of the heating elements.

The conductive pattern portions as the first and second power feeding electrode portions 19d to 19e are formed by coating, for example, by a screen printing method, and are made of a material with good conductivity, such as Au (gold).
These include Ag (silver) and Cu (copper).

Then, the heating element 19b, the first and second power feeding electrode parts 1
The surface of the substrate 19a on which the electrodes 9dj-19e are formed is coated with a glass material as a surface protective layer 19c, except for the surface portions on both ends of the substrate where the first and second power supply electrode portions 19d are present.
Coating method and baking method with a layer of heat-resistant and film-sliding material such as fluororesin such as PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin) and PTFE (polytetrafluoroethylene resin) It is formed with a thickness of about 1107z.

The heating body 19 having the above-mentioned structure is mounted and supported with the front side facing outward via the heat insulating member 20 on the bottom part 14 of the above-mentioned horizontally long stay 13 made of sheet metal as a support body.

In its attachment, in the supported state, the left and right ends of the heat insulating member 20 protrude outward from the left and right ends of the stay 13, and the power supply connectors 30 and 31 are fitted to the left and right outward protrusions.

The power supply connectors 30 and 31 are electrically connected to w41 and the second power supply electrode portions 19d and 19e, respectively, and are connected to a power supply circuit (not shown) via lead wires 30a and 31a, respectively.

As a result, the power supply circuit → lead wire 30a → first power supply connector 30 → first electrode part 19d of heating element 19 → heating element 19b → second electrode part 19e → second power supply connector 31 → lead wire 31a → Heating element 19b in the power supply circuit path
Electricity is applied to the heating element 19, causing the heating element 19 to generate heat.

Although not shown in the figure, a temperature measuring element such as a low heat capacity thermistor or a low heat capacity temperature measuring resistor such as a Pt film, and a safety element such as a fuse are arranged on the back side of the heating body 19.

The heating element 19b of the heating element 19 of this example is energized at a predetermined timing in response to an image forming start signal.
3 energization to generate heat over almost the entire length of b is AC100V
The supplied power is controlled by controlling the phase angle of energization by an energization control circuit (not shown) including a triac in accordance with the temperature detected by the temperature measuring element.

The heating element 19 heats the substrate 1 by energizing the heating element 19b.
Since the heat capacity of the entire heating element 9a, including the fist heating element 19b and the surface protective layer 19c, is small, the temperature of the heating element surface rapidly rises to the required fixing temperature (for example, 140 to 200° C.).

The heat-resistant film 21 in contact with the heating body 19 also has a small heat capacity, and the recording material sheet P is in pressure contact with the film via the film 21, which is the thermal energy key on the side of the heating body 19.
The image is effectively transferred to the side and thermal fixation of the image is performed.

As mentioned above, the surface temperature of the film facing the heating element 19 rises in a short time to a high enough temperature relative to the melting point of the toner (or the temperature at which it can be fixed to the recording material sheet P), which improves quick start performance. This is excellent because there is no need for so-called standby temperature control in which the temperature of the heating element 19 is raised in advance, energy saving can be achieved, and temperature rise inside the machine can also be prevented.

The heat insulating member 20 insulates the heating element 19 to make effective use of heat generated, and is made of materials having heat insulating properties and high heat resistance, such as PPS (polyphenylene sulfide), PAI (polyamideimide), PI (polyimide), and PEEK. (
Polyetheretherketone), liquid crystal polymer, and other highly heat-resistant resins.

(5) Example of Image Forming Apparatus FIG. 10 shows a schematic configuration of an example of an image forming apparatus incorporating the image heating and fixing apparatus 100 shown in FIGS. 1 to 9.

The image forming apparatus of this example is a laser beam printer using a transfer type electrophotographic process.

PC is a process cartridge, which includes a rotating drum type electrophotographic photoreceptor (hereinafter referred to as drum) 61 and a charger 62
- It includes four process devices: a developing device 6311 and a cleaning device 64. This process cartridge can be attached to and removed from a predetermined position within the apparatus by opening the opening/closing part 65 of the apparatus and opening the inside of the apparatus.

The Tochimura 1 is driven to rotate in the clockwise direction of the arrow by the image forming start signal, and the surface of the rotating drum 61 is connected to the charger 62.
The drum is uniformly charged to a predetermined polarity and potential, and is outputted from the laser scanner 66 to the charged surface of the drum. By performing main scanning exposure using the laser beam 67 modulated in accordance with time-series electric digital pixel signals of the desired image information, electrostatic latent images corresponding to the desired image information are sequentially formed on the surface of the drum 61. The latent image that is being formed is then developed into a toner image by a developing device 63.

On the other hand, the recording material sheets P in the paper feed cassette 68 are separated and fed one by one by the cooperation of the paper feed roller 69 and the separation pad 70, and are synchronized with the rotation of the drum 61 by a pair of registration rollers 71. and a transfer roller 72 that is in opposing pressure contact with the transfer roller 72 and is fed to a pressure nip 73 that is a fixing section,
The toner image on the first side of the drum is sequentially transferred onto the first side of the fed recording material sheet.

The recording material sheet P that has passed through the transfer section 73 is separated from the surface of the drum 61 and introduced into the fixing device 100 by a kite 74.
The unfixed toner image is heat-fixed by the operation and action of the device 100 described above, and is outputted from the output lower 5 as an image-formed product (print).

The surface of the drum 61 from which the recording material sheet P has been separated through the transfer section 73 is subjected to removal of adhered contaminants such as untransferred toner by a cleaning device 64, and is used repeatedly for image formation.

The heating device of the present invention can be effectively utilized not only as an image heating and fixing device of the image forming apparatus described above, but also as an image surface heating and polishing device, a temporary fixing device, and the like.

(Effects of the Invention) As described above, according to the present invention, the curl formation of the recording material after passing through the pressure nip portion N, which is a problem in film heating type heating devices, can be effectively corrected with a simple configuration, and recording It is possible to prevent troubles such as sheet jamming caused by material curling, and the intended purpose is well achieved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the device. Figure 2 is a longitudinal sectional view. Figure 3 is a right side view. Figure 4 is a left side view. FIG. 5 is an exploded perspective view of the main parts. FIG. 6 is an enlarged cross-sectional view of the main part showing the state of the film when not driven. FIG. 7 is the same diagram as above when driving. FIG. 8 is an explanatory diagram of the operation of the recording material separation guide member. FIGS. 9(A) and 9(CB) are a partially cutaway plan view and an enlarged cross-sectional view of the surface side of the heating body attached to the heat insulating member, respectively. FIG. 10 is a schematic configuration diagram of an example of an image forming apparatus. FIGS. 11 and 12 are schematic configuration diagrams of an example of an image heating fixing device using a film heating method, respectively. FIG. 13 is an explanatory diagram of curl formation (occurrence) on a recording material. 19 is a heating body, 20 is a heat insulating member, 21 and 51 are heat-resistant films, 13 is a stay, 10 is a roller as a rotating body,
33 is a recording material separation guide member. Patent applicant Canon Co., Ltd. 7 Figures 1 Kaya 6 Figures

Claims (2)

[Claims] (1) A fixedly supported heating body, a heat-resistant film that slides in close contact with the film sliding plane of the heating body, and a heat-resistant film sandwiched between the film sliding plane of the heating body. A heat-resistant film is produced by introducing a recording material between the heat-resistant film and the pressure roller at the pressure-contact nip between the heating body and the pressure roller, which are formed with a heat-resistant film in between. A heating device that applies heat from a heating body to the recording material through a heat-resistant film in the pressure nip by moving and passing through the pressure nip, and is disposed on the recording material exit side of the pressure nip, and It has a recording material separation guide member that conveys and guides the recording material that has passed through the nip portion while peeling it from the pressure roller, and the recording material guide surface of the recording material separation guide member ascends toward the downstream side in the recording material conveyance direction. A heating device characterized in that the surface is an inclined surface, and an end of the recording material guide surface on the downstream side in the recording material conveyance direction is located at a higher position than the pressure nip portion position. (2) The heating device according to claim 1, wherein the upward inclination angle A of the recording material guide surface of the recording material separation guide member is 10°≦A≦30°.