JPH0444079A - Heating device and image forming device - Google Patents

Abstract

PURPOSE:To prevent a film from slipping breadthwise, especially, outside a recording material by satisfying mu1>mu2, where mu1 is the coefficient of friction of the surface of a rotary body to the outer peripheral surface of the film and mu2 is the coefficient of friction of the surface of a heating body to the inner peripheral surface of the film. CONSTITUTION:The coefficient mu1 of friction of the surface of the roller (rotary body) 10 to the outer peripheral surface of the film 21 and the coefficient mu2 of friction of the surface of the heating body 19 to the inner peripheral surface of the film 21 are so related that mu1>mu2. For example, when mu<=mu2, the film 21 and a recording material sheet P slip in the sectional direction of a heat fixing means to disorder a toner image on a recording material sheet at the time of heat fixation. When, however, mu1>mu2, the film 21 and recording material sheet P are prevented from slipping on the roller 10 in the sectional direction. Consequently, the image disorder due to slip is prevented and a fixed image which is excellent is obtained stably at all times.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention introduces a recording material that supports a visible image on the side opposite to the heating body side of a heat-resistant film that is brought into pressure contact with a heating body and driven to move. A heating device of a method (film heating method) in which heat from the heating member is applied to the introduced recording material through the film by passing the heating member position together with the film in close contact with the film.
and an image forming apparatus using the same.

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. Recording materials (transfer cylinder sheet, electrofax sheet 1~,
An unfixed toner image corresponding to the desired image information, formed by an indirect (transfer) method or a direct method on the surface of an electrostatic recording sheet or printing paper, is transferred to the surface of the recording material carrying the image. It can be used as an image heat fixing device that heats and fixes a permanently fixed image.

Furthermore, it can be used, for example, in a device that heats a recording material carrying an image to modify its surface properties (to make it glossy), and in a device that performs temporary adhesion treatment.

(Background Art) Conventionally, 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 is often used, which heats the recording material while nipping and conveying it.

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

On the other hand, the present applicant has disclosed, for example, in Japanese Unexamined Patent Publication No. 63-313]82, etc., a fixedly supported heating body (hereinafter referred to as a heater) and a heat resistant It has a film and a pressure member that brings the recording material into close contact with the heater through the film, and by applying heat from the heater to the recording material through the film, the unfixed image formed and carried on the surface of the recording material is removed. We have proposed a system and configuration that heats and fixes the surface of the recording material, and have already put it into practical use.

More specifically, a thin heat-resistant film (or sheet)
a means for driving the movement of the film; a heater disposed with the film fixedly supported on one side of the film; The image fixing member has a pressure member that brings the image bearing surface of the recording material on which the image is to be fixed into close contact with the film, and the film is conveyed and introduced between the film and the pressure member at least when image fixing is performed. The recording material to be recorded is moved in the forward direction at a substantially concave speed and passed through a nip portion as a fixing portion formed by pressure contact between a heater and a pressure member with the traveling film sandwiched therebetween. Heat energy is applied to the developed image (unfixed toner image) by heating it with the heater through the film to soften and melt the developed image (unfixed toner image).Then, after passing through the fixing section, the film and the recording material are separated at a point. This is a heating means/device that is basically separated.

In such a film heating type device, since a heating element with a fast temperature rise and a thin film are used, it is possible to shorten the time from Way 1 (quick start).
It has the advantage of being able to solve various drawbacks of conventional devices,
It is effective. FIG. 13 shows a schematic configuration of an example of this type of image heat fixing device using an endless film as the heat-resistant film.

51 is an endless belt-shaped heat-resistant film (hereinafter referred to as F fixing film or film), which includes a driving roller 52 on the left side, a driven roller 53 on the right side, and a portion below between these driving rollers 52 and driven rollers 53. The three members 52, 53, and 54 of the arranged low heat capacity linear heating body 54 are parallel to each other.
A suspension cable is installed in between.

Does the fixing film 51 follow the clockwise rotation of the drive roller 52? The unfixed 1 to ner images Ta are conveyed at a predetermined circumferential speed in the poetic direction, that is, from the image forming section (not shown).
It is rotated at a circumferential speed approximately equal to the conveyance speed (process speed) of the recording material sheet P as a heated material carrying on the upper surface.

Reference numeral 55 denotes a pressure roller as a pressure member, which pinches the downward film portion of the endless belt-shaped fixing film 51 and presses it against the lower surface of the heating body 54 by a biasing means (not shown). , and rotates counterclockwise in the forward direction in the conveyance direction of the recording material sheet P.

The heating element 54 is a low heat capacity linear heating element whose length is the direction intersecting the plane movement direction of the film 51 (width direction of the film), and includes a heater substrate (base material) 56 and a current-carrying heating resistor (heating element) 57. - It is composed of a surface protection layer 58, a temperature measuring element 59, etc., and is fixedly supported by being attached to a support body 6j via a heat insulating material 60.

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 kite 62 and placed between the fixing film 51 at the pressure contact portion N between the heating body 54 and the pressure roller 55. The unfixed toner image portion enters between the fixing film 51 and the pressure roller 55, and the unfixed toner image portion comes into close contact with the lower surface of the fixing film 51, which is being rotated in the same direction and at the same speed as the conveyance speed of the recording material sheet 1-P, and is attached to the film. The heating elements 54 are overlapped together.
and the pressure roller 55, passing between the mutual pressure contact portion N.

The heating element 54 is heated with electricity at a predetermined timing, and the thermal energy on the heating element 54 side is transmitted to the recording material sheet 2 side that is in close contact with the film via the film 51, and the toner image Ta passes through the pressure contact part N. During this process, it is heated and becomes a softened and melted image Tb.

The fixing film 51 being rotated is one of the heat insulating materials 60.
At the 111% narrow edge S, the vehicle turns at a steep angle. Therefore, the old recording sheet P, which is conveyed through the pressure contact part N while overlapping with the fixing film 51, is separated from the fixing film 51 by the curvature at the edge part S and is discharged. By the time the toner reaches the paper discharge section, the toner has sufficiently cooled and solidified and is completely fixed to the recording material sheet P at a constant temperature of 71TC.

(Problems to be Solved by the Invention) The following problems are listed as problems with such a film heating type device.

That is, in the case where a rotary body presses and moves the film against the heating body, the coefficient of friction of the surface of the rotary body against the outer peripheral surface of the film is μ.
m ・The friction coefficient of the surface of the heating body against the inner peripheral surface of the film μ2 ・The friction coefficient of the surface of the rotating body against the surface of the heating body μ3 ・The friction coefficient of the outer peripheral surface of the film against the surface of the recording material μ4 ・The surface of the rotating body against the surface of the recording material The friction coefficient is μ5, and the maximum length of the recording material introduced into the device in the direction of the conveying force is f! , 1, ・When the apparatus is introduced into a transfer type image forming apparatus as an image heat fixing device, conveyance of the recording material from the image transfer means section to the nip section between the heating body and the rotating body of the fixing device. When the path length is ℃2, the relationship between μ4 and μ5 is μ4<
μ5 is set, and the relationship between 11 and °C2 is! 1>ρ2, but at this time, when μm≦μ2, the film and the recording material slip in the cross-sectional direction of the heat fixing means (the film conveyance speed is slower than the circumferential speed of the rotating body), and the heat fixation Sometimes, the toner image on the recording material is disturbed.

In addition, if the recording material and film slip together (the conveyance speed of the film and recording material is delayed relative to the circumferential speed of the rotating body), in the case of a transfer type image forming apparatus, the recording material ( When the toner image is transferred onto the recording material 1-, the toner image on the recording material 1- is also disturbed.

Further, in the relationship of μm≦μ3, the film and the rotating body slip in the width direction of the heat fixing means, and as a result, the film and the recording material slip, and the toner image on the sheet of material 24 is disturbed during heat fixation.

An object of the present invention is to provide a heating device that solves the above-mentioned problems associated with the film heating power type.

(Means for Solving the Problems) The present invention is a heating device and an image forming device characterized by the following configuration.

(1) A nip is formed by sandwiching the film between a fixed heating body, an endless heat-resistant film whose inner surface is pressed against the heating body and is driven to move, and a navigation heating body. a pressurizing rotary body introduced between the outer surface of the film in the nip portion and pressurizing the recording material supporting the microscope image to the heating body through the film, the pressurizing rotary body sandwiching the film; A rotating body is rotatably driven by a drive source while being in pressure contact with the recording heating body, and moves and drives the film at a predetermined speed in the recording material conveyance direction while sliding the inner surface of the film on the surface of the heating body. The friction coefficient of the surface of the rotating body is μm
A heating device characterized in that μ 1 >μ 2 , where μ 2 is the coefficient of friction of the surface of the heating body against the inner circumferential surface of the film.

(2) A nip is formed by sandwiching the film between a fixed heating body, an endless heat-resistant film whose inner surface is pressed against the heating body and is driven to move, and the navigation heating body. a pressurizing rotary body introduced between the outer surface of the film in the nip portion and pressurizing the recording material supporting the microscope image to the heating body through the film, the pressurizing rotary body sandwiching the film; The rotating body is in pressure contact with the heating body and is rotationally driven by a drive source to move the film at a predetermined speed in the recording material conveying direction while sliding the inner surface of the film on the surface of the heating body, and the surface of the rotating body relative to the outer circumferential surface of the film is The friction coefficient of is μ1, the friction coefficient of the surface of the rotating body against the surface of the heating body is μ3, the width of the film is C1, the length of the rotating body is Hl, the monthly length of the heating body is D, then C<H , C<D, and μm>μ3.

(3) The heating device according to claim 1 or 2 is disposed as an image heating and fixing device, and a recording medium formed by transferring an unfixed toner image by the transfer means is introduced into the device as a material to be heated. Features of the image forming device.

(Function) (1) When the film is driven and the heating body generates heat, the recording material is placed between the film and the rotating body in the nip formed between the heating body and the rotating body with the film sandwiched therebetween. When the recorder is introduced with the image-bearing surface facing the film, the recorder comes into close contact with the outer surface of the film and moves along with the film through the nip, and as it moves, it comes into contact with the inner surface of the film at the nip. Thermal energy of the heating body is applied to the recording material through the film, and the recording material supporting the visible image is heat-treated using a film heating method.

(2) The pressure contact part that presses the film against the heating element is in pressure contact with the heating element with the film in between, and is rotated by a drive source to slide the inner surface of the film against the surface of the heating element while conveying the recording material at a predetermined speed. A rotating body that is driven to move in the direction (
By using a roller body or endless heald body that performs both the functions of pressing and driving the film, the shifting force applied to the film can be reduced by one inch, and the position and position of the rotating body can be adjusted. Kia's position for driving the rotating body)+'
In order to improve the i-degree, the device configuration has been simplified,
The device can be inexpensive and highly reliable, and the total circumference length of the endless film used can be shortened.

(3) Also, 1) “As noted, the relationship between μm and μ2 is μ
By setting m>μ2, it is possible to prevent the film and the recording material from slipping with respect to the rotating body in the cross-sectional direction.

(4) Also, as mentioned above, under the conditions of C<H and C<D, by setting the relationship μm>μ3, it is possible to prevent the film from slipping against the rotating body in the width direction, especially on the outside of the recording material. can.

(5) By setting μm>μ2 and μm>μ3 in this way, the transport speed of the film and recording material can always be the same as the peripheral speed of the rotating body. Image disturbance can be prevented, and μm>μ
2. By simultaneously implementing μm>μ3, it is possible to always keep the circumferential speed of the rotating body (the process speed) and the transport speed of the film and recording material the same, and in a transfer type image forming apparatus, A stable fixed image can be obtained.

(Embodiment) The drawing shows an embodiment of the present invention (image heat fixing device 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 long device frame (bottom plate) made of sheet metal and has an upward channel-shaped cross section; 2 and 3 are a left side wall plate and a right side wall that are attached to the frame 1 at both left and right ends of the device frame 1; Plate 4 is the top cover of the device, and left and right side wall plates 2
・It is fitted between the upper ends of 3 and fixed by screwing the left and right ends to the left and right side wall plates 2 and 3, respectively. It can be removed by loosening and removing the screw 5.

6 and 7 are vertical notched elongated holes formed symmetrically in the approximately central portions of the left and right side wall plates 2 and 3, and 8 and 9 are elongated holes 6 and 7, respectively.
These are a pair of left and right bearing members that are fitted into one end of the shaft.

Reference numeral 10 denotes a film pressure roller (pressure contact roller, backup 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 left and right ends of the center shaft 11 are connected to the left and right bearing members 8, respectively.
・9 is supported by a bearing so that it can rotate freely.

Reference numeral 13 denotes a horizontally elongated stay made of sheet metal, which also serves as a supporting/reinforcing member for the two inner surface kites of the film 21, which will be described later, as well as the heating body 19 and the heat insulating member 20, which will be described later.

This stay 13 consists of 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 upright from both sides of the bottom part 14 in series.
It has a pair of left and right horizontally extending lug parts 17 and 18 that project outward from both left and right ends of the bottom part 14, respectively.

Reference numeral 19 denotes a horizontally long low heat capacity linear heating element having a structure (FIG. 6) which will be described later, and is supported by a horizontally long heat insulating member 2° (=J). The stay 13 is integrally mounted and supported in parallel with the lower surface of the oblong bottom surface portion 14 of the stay 13 facing downward.

21 is an endless heat-resistant film with a heating weight of 9
- It is externally fitted onto the stay 13 including the 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 19 and the heat insulating member 20 are larger than that of the film 21 by, for example, 3 mm. It is loosely fitted onto the stay 13 including the heat insulating member 20 with a circumferential margin.

22 and 23 connect the film 21 to the heating body 19 and heat 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. As described later, this pair of left and right flanges 2
Distance between inner surfaces 22a and 23a of nail seat of old 22 and 23・j
'Method G (Figure 8) is the width of the film 21 = J-Method C (same)
It is set slightly larger than that.

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.
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, so that the left and right flanges 2, the old 22, and
I firmly support 23.

To assemble the device, remove the cover 4 from between the left and right side wall plates 2 and 3, and press the film with the bearing members 8 and 9 fitted on the left and right ends of the support 11. The left and right bearing members 8 and 9 of the roller 10 are connected to the left 'I-i side wall plate 2.
・Insert the pressure roller 10 between the left and right side wall plates 2 and 3 by fitting it into the vertical notched elongated holes 6 and 7 of No. 3 from the open upper end, and then insert the pressure roller 10 between the left and right side wall plates 2 and 3, and insert the pressure roller 10 into the left and right bearing members 8 and 9 or the elongated holes 6 and 7. Receiver 1 at the bottom end of
1- Lower it to the position where you can see it (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 turned with the heating body 19 side facing -F. In addition, the left and right outwardly protruding ends of the heat insulating member 20 and the horizontally projecting lug portions 24 and 25 of the left and right flange members 22 and 23 are inserted into the vertical notched elongated holes 6 and 7 of the left and right side wall plates 2 and 3, respectively, from the open upper end. Fit and engage the left and right side wall plates 2 and 3.
Insert the film 21 between the film 21 and heat it until the downward heating element 19 hits the surface of the previously assembled pressure roller 10 with the film 21 in between and the receiver is stopped (drop-in type).

Additionally, coil springs 26 and 27 are attached to the lug portions 24 and 25 of the left and right flange members 22 and 23, respectively, which protrude through the long holes 6 and 7 on the closed side of the side wall panels 2 and 3. The upper cover 4 is positioned vertically using the supporting protrusions provided on the upper surface of the lug portion, and the outer projecting lug portions 28 and 29 provided on the left and right end sides of the upper cover 4, respectively, are set vertically. The coil springs 26 and 27 are connected to the lug portions 24, 28, 25, and 291 in correspondence with the upper ends of the set coil springs 26 and 27, respectively.
Don't compress it to 11, left! Side wall plates 2 and 3 of j Q) Insert until the specified position between the upper ends and screw 5 to the left! Fix it between side wall plates 2 and 3 of 1'.

As a result, the stay 13, heating element 19, heat insulating member 20, film 2I,
The entire left and right flange members 22 and 23 are pressed downward, and the heating body 19 and the pressure roller 10 are brought into contact with the film 21 almost equally on each longitudinal part with a contact pressure of, for example, 4 to 7 kg in total. is maintained in the same state.

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

Reference numeral 32 denotes a heated material artificial kite placed on the front wall of the device frame 1, which is a recording material that supports a visible image (powder toner image) Ta as a heated material introduced into the device. The sheet P (FIG. 7) is guided toward a 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 roller 1o.

33 is a heated kite (separation kite) installed on the rear wall of the device frame 1, and the recording material sheet that has passed through the nib part is transferred to the lower ejection roller. 3
4 and the upper end roller 38.

The U1 output roller 34 is rotatably supported by bearings at both left and right ends of its shaft 35 between bearings 36 and 37 provided on the left and right side wall plates 2 and 3. The shaft 38 is attached to a hook portion 4 formed by bending a part of the rear wall of the upper cover 4 inward.
The receiver is placed in the position 0 and brought into contact with the upper surface of the discharge roller 34 by its own weight and the push spring 41. This Pinjikoro 38
is rotated by the rotational drive of the U1 output roller 34.

G1, the roller shaft 11 projected outward from the right side wall plate 3;
The first Kia stuck to the right end of the G3, and the right side wall plate 3
The third gear, G2, is fixed to the right end of the discharge roller @35 that protrudes outward from the! This is a second gear as a relay gear provided pivotally on the outer surface of the first side wall plate 3, and is similar to the first gear G described above.
1 and the third Kia 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. This 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 Kia G1 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 inner surface of the endless heat-resistant film 21 slides on the surface of the heating body 19 at approximately the same speed as the circumferential rotation speed of the pressure roller 10 in the clockwise direction A. 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 on the second flow side in the film rotation direction with respect to the nip part N, so that the film 21 is moved further away from the nip part N as shown by the solid line in FIG. Also, on the upstream side in the film rotation direction, the inner surface of the film near the nip portion, that is, the approximately lower half surface portion of the outward arc curved front plate 15 as the inner surface of the film of the stay 13 on which the film 21 is externally fitted. It contacts and rotates while producing sliding motion.

As a result, the rotating film 21 rotates with tension acting on the film portion B from the starting point O of the contact sliding portion with the front plate 15 to the nip portion N on the upstream side in the film rotation direction. This means that wrinkles can be prevented from occurring on at least the film part surface, that is, the film part surface B in the vicinity of the recording material sheet entrance side of the nip part N, and the film part in the nip part N. .

Then, in the state in which the film is driven as described in - 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 guided by the human guide 32 into the nip. When the recording material sheets 1 to P are introduced between the rotary film 21 of the section N and the pressure roller 10 with the image bearing surface facing upward, the recording material sheets 1 to P come into close contact with the film 21 and move through the nip section N together with the film 21. During the movement and passing process, the recording material sheet P is heated through the film by the thermal energy of the heating element 19 that is in contact with the inner surface of the film at the nip portion N.
The toner image Ta becomes a softened and fused image Tb.

The recording material sheet P that has passed through the nip portion N separates from the surface of the film 21 in a state where the toner temperature is lower than the glass transition point and comes out through the log gate 33 and is guided between the discharge roller 34 and the punch roller 38 and sent out of the apparatus. It will be done. Recording material sheet P
The softened/melted toner image Tb is cooled and fixed as a solidified image TCL/ during the time it exits the nip portion N, leaves the surface of the film 21, and reaches the discharge roller 34.

Recording material sheet 1- introduced into the nip portion N in 1-
As mentioned above, P is under tension and always stays in close contact with the surface of the unwrinkled film portion and moves through the nip N together with the film 21, so that a situation occurs where the wrinkled film passes through the nip N. There is no occurrence of heating unevenness/fixing unevenness due to printing, and no folding of the film mi.

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 driven (Fig. 6), the film 21 is at the nip portion N.
Almost the entire circumference of the remaining part, excluding Since most of the almost entire circumference is tension-free, the overall circumference is %
Since a thin film can be used, the drive torque required for driving 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 applied to 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 hot water pressure 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 hot water pressure inner surface 23a, the film's biasing force is small, so the rigidity of the film can overcome the biasing force by -1-min and prevent the edge of the film from buckling or breaking. Does not occur. The film deviation regulating means is simple flange members 22 and 23 as in the device of this embodiment.
suffices, so in this respect as well, the device configuration can be simplified,
The cost can be reduced and an inexpensive and highly reliable device can be constructed.

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. In addition, as shown in F, the rigidity of the film 21 can be reduced to compensate for the reduction in bias force, so a thinner film with a smaller heat capacity can be used to improve the quick start performance of the device. can be improved.

(3) Regarding film 21.

In order to reduce heat capacity and improve quick start performance, the film 21 has a total IIQ thickness T of 100 μm or less, preferably 40 μm or less, and has heat resistance, mold releasability, strength, and durability f of 20 μm or more. Single layer or composite layer films can be used.

For example, Boliimi I...polyetherimide (PET)
・Polyether sulfone (PES) 4-functional polymer fluoroalkyl vinyl ether copolymer resin (PFA) ・Polyether ether ketone (PEEK)
)・Polyparabanic acid (PPA), or a composite layer film such as 20 μm thick polyimide 1 to PTFE (tetrafluoroethylene resin) P on at least the image contact side of the film
A releasable coating layer made of fluororesin such as AF-FEP, silicone resin, etc. and a conductive material (carbon black, graphite, 4-qualitative whiskers, etc.) added thereto is applied to a thickness of 10 μm.

(4) Regarding the heating body 19 and the heat insulating member 2o.

The heating element 19, similar to the heating element 54 of the apparatus shown in FIG. 13, is composed of a heater substrate 19a (see FIG. 6), an energized heating resistor (heating element) 19b, a surface protection layer 19c, a temperature measuring element 19d, and the like.

The heater board 19a is a heat-resistant, insulative, low heat capacity, and highly thermally conductive member, and has a thickness of 1 mm and 11"10, for example.
It is an alumina substrate with a length of 240 mm.

The heating element 19b is located on the lower surface of the heater board 19a (the illumination 21
For example, Ag
/Pd (silver palladium), Ta2N, RuO2, or other electrically resistive material is coated in the form of a line or strip with a thickness of about 1071 m/111 to 3 mm by screen printing, etc., and heat-resistant glass is applied as a surface protective layer 19c on top of it. Approximately 10μm
It is coated. The temperature measuring element 19d is, for example, a heater taco, a PT Ili, etc., which is provided by screen printing or the like on the approximate center of the upper surface of the plate 19a (the side opposite to the surface on which the heating element 19b is provided). It is a low heat capacity resistance temperature detector.It can also be used as a low heat capacity thermistor.

In the case of the heating element 19 of this example, the heating element 1.9b, which has a linear or narrow strip shape, is energized at a predetermined timing in response to an image formation start signal to cause the heating element 19b to generate heat over substantially its entire length.

The power supply is AClooV, and the supplied power is controlled by controlling the phase angle of the current supply by a power supply control circuit (not shown) including 1 to LIACT according to the temperature detected by the temperature measuring element 19c.

When the heating element 19 is energized, the surface of the heating element reaches a required fixing temperature (for example, 14
The temperature rises rapidly from 0 to 200°C.

The heat-resistant film 21 in contact with the heating element 19 also has a small heat capacity, and the recording material sheet 2 in pressure contact with the film via the heating element 19 receives thermal energy from the heating element 19 side.
The image is effectively transferred to the side and thermal fixation of the image is performed.

'', the surface temperature of the film facing the heating element 19 rises to a high enough temperature for the melting point of 1 hener (or the temperature at which it can be fixed on the recording material sheet P) in a short period of time, so the quick start is possible. There is no need for so-called standby temperature control in which the heating element 19 is warmed up, 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 that have heat insulating properties and high heat resistance, such as pps (polyphenylene sulfite), PAT (polyamideimide), and PI (polyimide).・PEEK (
Polyetheretherketone), liquid crystal polymer, and other highly heat-resistant resins.

(5) Regarding film width C and nip length.

As shown in the (1 method relationship diagram) in FIG. 8, the width of the filler no. In this case, it is better to set the relational structure such that C<D.

In other words, when the film 21 is conveyed by the roller 10 with the relationship C20, contrary to the above, the film conveying force (pressing force) received by the film portion within the nip length area and the film outside the nip length area are The inner surface of the former film portion is slidably transported in contact with the heating element 19, while the inner surface of the latter film portion is insulated from a different material from the surface of the heating element 19. Member 20
Since the film 21 is slidably conveyed in contact with the surface thereof, there is a possibility that damage such as wrinkles or folds may occur at both ends of the film 21 in the width direction due to the large difference.

On the other hand, by setting the relational structure of C<D, the inner surface of the entire length C in the width direction of the film 21 or the surface within the length range of the heating element 19 can be contacted and the surface of the heating element can be slid. Since the film is transported, the film transport force is made uniform over the entire length region C in the width direction of the film, thereby avoiding the problem of film end damage as described above.

In addition, the pressure roller 10 used as a rotating body in this embodiment is made of a highly elastic comb material such as silicone rubber.
When heated, the coefficient of friction of the surface changes. Therefore, when the length range dimension of the heating element 19b of the heating element 19 is E, the friction coefficient between the roller 10 and the film 21 at the portion corresponding to the length range E of the heating element 19b,
The coefficient of friction between the roller 10 and the film 21 differs in a portion corresponding to the outside of the length range E of the heating element 19b.

However, by setting the dimensional relationship configuration of E<C<D, the difference between the length range E of the heating element 19b and the film width C can be reduced, so that the difference between the length range E of the heating element 19b and the film width C can be reduced. The difference in the coefficient of friction between the roller 10 and the film 21 can reduce the influence on film transport.

This makes it possible to stably drive the film 21 with the roller 10, making it possible to prevent the edges of the film from being damaged.

Flange members 22 and 23 as film end regulating means
The film end regulating surfaces 22a and 23a are the pressure roller 10.
The length is within the range of , and even if the film shifts, the edges of the film are prevented from being damaged.

(6) Regarding the pressure roller 10.

The pressure roller 10, which forms a nip N with the film 21 sandwiched between it and the heating body 19, and serves as a rotating body for driving the film, is made of a rubber elastic body with good rigidity, such as silicone rubber, for example. 9 (A) or (
It is preferable to have an inverted crown shape as shown in the exaggerated model diagram of B), or a substantially inverted crown shape in which the end portion of the inverted crown is cut 12a.

When the effective length H of the roller 10 is, for example, 230 mm, the degree d of the inverted crown may be set to d - 100 to 200 μm.

That is, in the case of a straight shape, the pressure distribution in the width direction of the film applied by the roller to the film 21 at the nip N with the heating element 19 is greater at the center than at the ends in the width direction due to variations in particle size of the parts. It could get expensive. In other words, the conveyance force of the film by the roller is greater at the center than at the ends in the width direction of the film, and the film 21 is affected by the force that causes the portion of the film with a smaller conveying force to move toward the portion of the film with a larger conveying force as it is conveyed. Therefore, wrinkles may occur in the film as it approaches the edges of the film or the center of the film.
Furthermore, when the recording material sheet P is introduced into the nip portion N, wrinkles may occur in the old recording sheet P during the conveyance process through the nip portion.

On the other hand, by forming the pressure roller 10 into an inverted crown shape, the pressure distribution in the film width direction applied by the roller to the film 21 at the nip N with the heating element 19 is opposite to the above case. The edges in the width direction are larger than the center, and as a result, a force acts on the film 21 from the center toward both ends, that is, the film 21 is conveyed while being subjected to a wrinkle smoothing effect.
It is possible to prevent the film from being wrinkled, and also to prevent the introduced recording material sheet P from being wrinkled.

The pressure roller 10 as a rotary body presses the film 21 against the heating body 19 by sandwiching the film 21 between it and the heating body 19 as in the apparatus of this embodiment, and drives the film 21 to move at a predetermined speed to When a recording material sheet P as a heated side is introduced between the film 21 and the film 21, the recording material sheet P is brought into close contact with the film 21 surface, pressed against the heating body 19, and driven to move together with the film 21 at a predetermined speed. By making it a member, it is possible to reduce the biasing force applied to the film, and it is also possible to improve the positional accuracy of the pressure roller 10 and the gear for driving the roller.

That is, the film 21 or the film 2
1 and the recording material sheet P, and a drive function to move and drive the film 21, are provided by separate pressurizing rotary bodies (the necessary pressurizing force is obtained by pressurizing these rotary bodies). ) and a film drive function rotating body, if the alignment between the heating body 19 and the film drive function rotary body goes out of alignment, a large biasing force in the width direction will be applied to the thin film 21. As a result, the edges of the film 21 may be bent, wrinkled, or otherwise damaged.

In addition, a heating body 1 is attached to the pressurizing rotary body that also serves as a film drive member.
When applying the pressure necessary for pressure contact with 9 by pressing with a spring or the like, the position of the rotating body and the positional granularity of the gear for driving the rotating body are determined.

On the other hand, as described above, a pressure necessary for fixing is applied to the heating body 19, and the pressure roller 10, which is a rotating body, presses the recording material sheet P through the film 21, and the recording material sheet P and By driving the film 21 at the same time, the above-mentioned effects can be obtained, and the structure of the apparatus can be simplified, resulting in an inexpensive and highly reliable apparatus.

Incidentally, instead of the roller 10, the rotating body may be an endless hell l-1OA which is rotationally driven as shown in FIG.

Rotating body 10.1. The configuration in which the OA has the function of bringing the film 21 into pressure contact with the heating body 19 and the function of driving the film 21 is suitable for a film tension-free type device like the device of this embodiment (at least a part of the film 21 is driven by the film J1). A film tension type device (such as the device shown in Fig. 13 above, which constantly applies tension to the entire circumference of a film with a long circumference to maintain tension). The same operation and effect can be achieved regardless of whether the film deviation regulating means is a sensor/solenoid method, a rib regulating method, a film edge regulating method (both sides (Ill or one side)), etc. However, it is particularly suitable for application to a tension-free type device configuration.

(7) Regarding recording material sheet ejection speed.

Let VIO be the conveyance speed of the recording material sheet P as a heated material introduced into the nip portion N by the pressure roller 10 (rotating body), that is, the circumferential speed of the roller 10, and the output conveyance of the recording material sheet jJj by the discharge roller 34. When the speed, that is, the circumferential speed of the discharge roller 34 is V34, it is better to set the speed relationship such that VIO>V34. The speed difference is a few percent, for example 1 to 3%.
It is sufficient to set the degree.

When the maximum width of the recording material sheet P that can be introduced into the apparatus and used is F (see FIG. 8), in relation to the width C of the film 21, under the condition of F<C, VIO≦V3.
4, the recording material sheet P that is being conveyed astride between the nip portion N and the D ejection roller 34 has a portion of the sheet that is passing through the nip portion N that is conveyed between the nip portion N and the D ejection roller 34.
Pulled by 4.

At this time, the film 21 whose surface is coated with PTFE or the like having good mold releasability is being conveyed at the same speed as the pressure roller 10.

In addition to the conveyance force by the pressure roller 10, a tensile conveyance force by the discharge roller 34 is also applied to the recording material sheet P.
It is transported at a speed faster than the circumferential speed of the pressure roller 10. In other words, at the nip portion N, the recording material sheet P and the film 21
This causes a slipping condition, which causes the recording material sheet P to slip.
During the process of passing through the nip N, the unfixed toner image Ta (FIG. 7) or the softened/melted toner image Tb of the recording material sheet P is disturbed.
There is el.

Therefore, as described above, by setting the circumferential velocity VIO of the pressure roller 10 and the circumferential velocity V34 of the discharge roller 34 in the relationship of VIO>V34, the recording material sheet P and the film 2
1, since the pulling tension force by the discharge roller 34 does not act on the sheet P and only the conveying force of the pressure roller 1o is applied,
The slip between the sheet P and the film 21 can also prevent the above-mentioned image blur from occurring.

Although the discharge roller 34 is provided on the heating device 100 side in this embodiment, it may be provided on the Kasagi machine side of the image forming apparatus into which the heating device 100 is incorporated.

(8) Regarding the film edge regulation flange spacing.

Hot water pressure inner surface 22 as a film end regulating surface of a pair of left and right flange members 22 and 23 as film end regulating means
When the distance between a and 23a is G (FIG. 8), the relationship with the width C of the film 21 may be set such that C<G. For example, when C is set to 230 mm, G is set approximately 1 to 3 mm larger.

That is, the film 21 has a thickness of, for example, 200 at the nip portion N.
It expands upon receiving the heat from the heating element 19 at a temperature close to 0.degree. C., and its dimension C increases. Therefore, if the width dimension C of the film 21 and the flange interval dimension G at room temperature are set to C=G, and both ends of the film 21 are regulated by the flange members 22 and 23, the thermal expansion of the film described above occurs when the device is in operation. By C>
produces the state of G. Since the film 21 is a thin film of about 50 μm, for example, in a state where C>G, the film end regulating surfaces 22a and 23a of the flange members 22 and 23
The end contact pressure (end pressure) of the film 21 increases, and before it is able to withstand the pressure, the end part is subject to damage such as bending and buckling. Since the frictional force between the film end regulating surfaces 22a and 23a of the flange members 22 and 23 also increases, the film conveyance force is also reduced.

By setting the = J-law relationship of C<G, even if the film 21 expands due to heating, the gap (C
, C) are provided between both ends of the film 21 and the film end regulating surfaces 22a and 23a of the flange member, so that both ends of the film 21 do not come into contact with the film end regulating surfaces 22a and 23a of the flange member at the same time. .

Therefore, even if the film 21 expands thermally, the film end pressure contact force does not increase, making it possible to prevent damage to the end of the film 21 and to reduce the film driving force.

(9) Regarding the friction coefficient relationship between each member.

a, roller (rotating body) 1 against the outer peripheral surface of the film 21
0 The friction coefficient of the surface is μ1, b The friction coefficient of the heating body 19 surface against the inner peripheral surface of the film 21 is μl, C The friction coefficient of the roller 10 surface against the heating body 19 surface is μ3, d, Recording material as heated material The friction coefficient of the outer peripheral surface of the film 21 with respect to the surface of the sheet 2 is μ4, e, the friction coefficient of the surface of the roller 1o with respect to the surface of the recording material sheet 2 is μ5, f, the maximum length in the transport direction of the recording material sheet P introduced into the apparatus. 21. g When the device is incorporated into a transfer type image forming device as an image heat fixing device, the recording material from the image transfer means section to the image heat fixing device and the nip portion N of the device in 1. Convey path length of sheet (transfer material) P! 2.

Therefore, the relationship between μl and μl is μl>μl The relationship structure is as follows.

That is, in this type of film heating type device, the relationship between the surface numbers μ4 and μ5 is set as μ4<μ5, and in the image forming device, the relationship between the above 11 and °C2 is 11 > 12. .

At this time, if μm≦μ2, the film 21 and the recording material sheet P slip in the cross-sectional direction of the heat fixing means (the transport speed of the film 21 lags behind the circumferential speed of the roller 10).
The toner image on the recording material sheet is disturbed during heat fixing.

In addition, if the recording material sheet P and the film 21 slip together (the conveyance speed of the film 21 and the recording layer sheet P is delayed due to the circumferential speed of the roller 10), in the case of a transfer type image forming apparatus, When the toner image is transferred onto the recording material sheet (transfer material) in the image transfer means section, the toner image of the recording material is also disturbed.

By setting μm>μl as described above, the film 21 and the recording material sheet + are connected to the roller 10 in the cross-sectional direction.
can prevent slipping.

Furthermore, regarding the width C of the film 21, the length H of the roller 10 as a rotating body, and the length H of the heating body 19, under the conditions of C<H, c<D, the relationship configuration is μm>μ3. Make it.

That is, if μl≦μ3, in the width direction of the heat fixing means,
The film 21 and the roller 1o slip, and as a result, the film 21 and the recording material sheets 1 to P also slip, and the toner image on the recording material sheet is disturbed during heat fixing.

By establishing the relationship μl>μ3 as described above, it is possible to prevent the film 21 from slipping against the roller 10 in the width direction, especially on the outer surface of the recording layer sheet P.

By setting μm>μl and μm>μ3 in this way,
The conveyance speed of the film 21 and the recording layer sheet P can always be the same as the circumferential speed of the roller 10, and it is possible to prevent image blurring during fixing or transfer, and μm>μ.
By simultaneously implementing l, μl>μ3, roller 1
It becomes possible to always keep the peripheral speed of 0 (=process speed) and the conveying speed of the film 21 and the recording material sheet P the same, and a stable fixed image can be obtained in a transfer type image forming apparatus. .

(10) Regarding film shift control.

The film shift control of the embodiment apparatus shown in FIGS. 1 to 10 is performed by disposing a pair of left and right flange members 22 and 23 on both ends of the film 21 in the width direction for use in controlling the film edges. The following configuration is also effective as a method to deal with the deviation movement QR of the film (film both-side edge restriction type) or a film one-side edge restriction type.

That is, the left and right pressure coil springs 26 and 27 are driven, for example, as in the apparatus shown in FIG. By setting the force f27 of the spring 27 on the side to be higher than the force f26 of the spring 26 on the non-driving side (f27>f26), the film 21 is always moved toward the right side R, which is the driving side. In addition, the shape of the heating element 19 and the shape of the roller 10 can be changed between the drive end side and the non-drive end side to control the film conveyance force so that the film always moves in one direction. The end of the film on the closer side is regulated by means such as a flange member as a regulating member for the end of the film on that side, a film rib and an engagement guide member, etc. In other words, in the apparatus shown in FIG. 11, the film 21 Only the end of the R is restricted by the regulating member 27.
By regulating the film deviation, it is possible to stably and easily control the film deviation. As a result, when the apparatus is an image heat fixing apparatus, a stable and good fixed image can always be obtained.

Further, since the film 1 to the film 21 are driven by the pressure roller 10 forming the nip portion N, no special drive roller is required.

These effects can be obtained both in the case of a tension-type device configuration in which the film is driven by applying tension all around it, and in the case of a tension-free type device configuration like the device of this embodiment. However, the means structure is particularly suitable for tension-free types.

(11) Example of Image Forming Apparatus FIG. 12 shows a schematic configuration of an example of an image forming apparatus incorporating the image heat fixing apparatus 100 shown in FIGS. 1 to 10.

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

60 is a process cartridge, which includes a rotating drum type electrophotographic photoreceptor (hereinafter referred to as ram) 61 and a charger 6
It includes four process devices: 2, developing device 6.3, and 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 drum 61 is driven to rotate in the clockwise direction indicated by the arrow in response to the image forming start signal.
2 to a predetermined polarity and electric charge 17, and modulated in accordance with a time-series electric digital pixel signal of IJ-like image information outputted from a laser scanner 66 to the charged surface of the drum. By performing main scanning exposure using the laser beam 67, an electrostatic latent image corresponding to the target image information is sequentially formed on the surface of the l-ram 61. The latent image is then developed into a toner image by a developing device 63.

On the other hand, the recording material sheets 1 to 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 bat 70, and are synchronized with the rotation of the tram 61 by a pair of registration rollers 71. The tram 61 is fed to a pressure nip 73 which is a fixing portion between the tram 61 and a transfer roller 72 which is in pressure contact with the tram 61, and
The toner image on the first side of the drum is sequentially transferred onto the P side of the fed recording side 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 via a guide 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 and a temporary fixing device.

(Effects of the invention) As described above, the film heating type heating device of the present invention has the following features:
This makes it possible to always keep the circumferential speed of the rotating body and the transport speed of the film and the recording material (heated material) the same by preventing slips between them. It is possible to always stably obtain a good fixed image by preventing image disturbance caused by the above-mentioned slip.

By driving the film with a pressurizing rotor, the structure of the apparatus can be further simplified and costs can be reduced.

[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 a dimensional relationship diagram of the constituent members. Figures 9(A) and 9(B) each show the roller 1 as a rotating body.
An exaggerated shape diagram showing an example of the shape of 0. FIG. 10 is a diagram showing an example in which a rotating belt is used as the rotating body. FIG. 11 is a longitudinal cross-sectional view of an example of a device in which the end of the film sheet 1 is restricted. FIG. 12 is a schematic configuration diagram of an example of an image forming apparatus. FIG. 13 is a schematic diagram of a known example of a film heating type image heating fixing device. 19 is a heating body, 21 is an en 1 (less film), 13 is a stay, and 10 is a roller as a rotating body.

Claims (3)

[Claims] (1) A fixed heating body, an endless heat-resistant film whose inner surface is pressed against the heating body and is driven to move, and the film is sandwiched between the heating body to form a nip portion, and the nip portion is formed by sandwiching the film between the heating body and the heating body. a pressurizing rotary body which is introduced between the outer surface of the film in the section and presses the recording material supporting the microscope image onto the heating body through the film, the pressurizing rotary body sandwiching the film between the recording material and the heating body; A rotating body that is in pressure contact with the heating body and is rotationally driven by a drive source to move the film at a predetermined speed in the recording material conveying direction while sliding the inner surface of the film on the surface of the heating body, and the surface of the rotating body relative to the outer circumferential surface of the film is The friction coefficient of μ1
A heating device characterized in that μ1>μ2, where μ2 is the coefficient of friction of the surface of the heating body against the inner peripheral surface of the film. (2) A fixed heating body, an endless heat-resistant film whose inner surface is pressed against the heating body and is driven to move, and the film is sandwiched between the heating body to form a nip portion, and the nip portion is formed by sandwiching the film between the heating body and the heating body. a pressurizing rotary body which is introduced between the outer surface of the film in the section and presses the recording material supporting the microscope image onto the heating body through the film, the pressurizing rotary body sandwiching the film between the recording material and the heating body; The rotating body is in pressure contact with the heating body and is rotationally driven by a drive source to move the film at a predetermined speed in the recording material conveying direction while sliding the inner surface of the film on the surface of the heating body, and the surface of the rotating body relative to the outer peripheral surface of the film is When the coefficient of friction is μ1, the coefficient of friction of the surface of the rotating body against the surface of the heating body is μ3, the width of the film is C, the length of the rotating body is H, and the length of the heating body is D, C<H , C<D, and μ1>μ3. (3) The heating device according to claim 1 or 2 is arranged as an image heating and fixing device, and a recording material on which an unfixed toner image is transferred and formed by the transfer means is introduced into the device as a material to be heated. image forming apparatus.