JP2003307951A - Heat fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prolong the service life of a fixing device and to shorten the first print out time. <P>SOLUTION: In a means where pressing quantity of a fixing pressing member is variable and the pressing quantity is controlled, the control method for the pressing quantity consists of a routine which is high pressure before passing a nip → medium pressure when passing → low pressure after ejection of paper. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention
Image forming such as electrophotographic apparatus or electrostatic recording apparatus
It concerns the device. 2. Description of the Related Art Generally, as a fixing device of an image forming apparatus.
Uses a heat roller fixing device. Here, the conventional
The structure of the dressing device is shown in the figure. A heat fixing device has a halogen source, which is a heat source, inside.
The metal fixing roller on which the
Introduces recording material into the rubber pressure roller and roller nip
Separating the recording material from the entrance guide and the fixing roller
The separation claw and the recording material separated by the separation claw
Guided by a transport guide located downstream,
It is discharged out of the device by a pair. Separating claw on fixing roller
A plurality of fixing rollers are arranged in the direction of the fixing roller in contact with each other.
It is separated directly from the fixing roller. Fixing roller side of recording material
The image plane receives heat, and the degree of shrinkage is larger than that of the non-image plane.
The end of the recording material that has passed through the fixing nip
Curled to the side and guided by the transport guide. [0004] However, the separating claw
If the edge of the recording material is located in the area without
Fixing roller compared to where the end of the recording material has a separation claw
Is separated from the paper, and collides with the conveyance guide, causing paper jams.
There was a problem of causing it. [0005] Further, the recording material is made of thin paper such as thin paper.
In this case, the curl of the leading end of the recording material
Therefore, the sheet easily collides with the transport guide and paper jams easily occur. Also, the recording material does not collide with the conveyance guide.
As described above, fix the end of the conveyance guide in the recording material conveyance direction to the fixing roller.
Fusing roller and pressure through the nip between the roller and pressure roller.
How to make it far away from the normal of the straight line connecting the center with the roller
In this case, the leading edge of the recording material lands on the transport guide
Angle becomes large, and eventually the transport guide is smooth.
Not jammed, causing paper jam. Alternatively, the curl at the end of the recording material is large.
In addition, as a method of reliably guiding to the transport guide, a separation claw
Increase the number of papers and arrange them closer to the center of the recording material than the end of the recording material.
However, the number of parts, assembly time,
Cause of image stain on recording material due to adhesion of toner to the tip
Become. [0008] The present invention has been made in view of the above problems.
The purpose is to use the recording material separated by the separation claw.
Fixing device that can always reliably guide the conveyance guide
Is to provide. [0009] To achieve the above object,
Therefore, the invention according to claim 1 provides a fixing roller and a fixing roller.
A pressure roller for forming a nip by pressing, and the fixing roller
Downstream of the nip portion between the fixing roller and the pressure roller, to the fixing roller side.
The transport guide member and the recording material are arranged from the fixing roller.
In a fixing device having a plurality of separation claws to be separated,
At the end of the conveyance guide member in the recording material conveyance direction, the fixing
The fixing device passes through a nip portion between a roller and the pressure roller.
From the normal of the straight line connecting the center of the roller and the pressure roller
There are multiple guide surfaces starting from the end where the distance of
And, of the surface through which the end of the recording material passes among the guide surfaces,
The distance between the end of the nearby recording material conveyance direction and the normal is
It is characterized by being large. The invention according to claim 1, wherein the separation claw is provided.
Distance between the end of the nearby surface in the recording material transport direction and the normal
Is the minimum. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
Next, embodiments of the present invention will be described in detail. FIGS. 1 and 2 show a first embodiment of the present invention.
1 is a top view of the fixing device, and FIG. 2 is a dotted line shown in FIG.
It is the principal sectional view cut | disconnected by A. In FIG. 1, reference numeral 1 denotes a fixing frame, and 2 denotes a fixing frame.
Pressure frame, 3 is an aluminum fixing roller, 4 is a fixing roller
The rubber pressure roller 5 that presses against the
Gen heater, 6 is a fixing entrance guide, 7 is a fixing frame.
The first transport guide, which is a part of the first transport guide, is paired with the first transport guide.
The second transport guide 9 arranged to face the first transport
Separation claw arranged at the upstream end of the guide, 10
This is the center line that is used as the reference for the material being transported. 7a and 7b are first conveying guides having different gradients.
Some aspects of the do. 7c has the same gradient as 7b. B
5, the ends of the A4 size recording material are 7b and 7c, respectively.
Conveyed along the guide. In FIG. 2, the B5 size that has exited the fixing nip
The leading end S1 of the recording material is fixed by a separation roller by a separation claw.
From the first transport guide 7a
Indicates a state in which On the other hand, the leading portion S2 at the end of the recording material
Is not directly separated by the separating claw,
Separation is delayed. Also, use weak recording materials such as thin paper.
Means that the curl becomes larger on the side of the fixing roller. Therefore, S
If the conveying guide surface through which 2 passes has the same gradient as 7a,
S2 is guided perpendicular to the guide surface and collides, and the leading end of the recording material
Is likely to break and cause paper jams. Then, S2
The upstream end of the passing conveyance guide surface is 7a like 7b.
Is located farther from the nip compared to
You. By doing so, S2 does not collide with the guide surface at an obtuse angle
Only Then, when the recording material is changed from S1 and S2 to 1
When transported by about 5 mm, they are indicated by broken lines S1 'and S2'.
As a result, due to the stiffness of the recording material, S2 '
It can also cause jams. So the fixing roller 2 and
When the distance to the separation parts 7a-d is set to about 0.5mm
Good results were obtained. If the separation angle is set large, the leading edge of the paper
Because the angle around the fixing roller increases,
However, the present invention partially adjusts the setting of the separation angle.
Larger size minimizes impact on tip curl
It is possible to obtain. Separation section 7b is A4 / LTR size
Paper is located on the inside instead of the edge but separated
Since the center of the paper is more favorable,
No digitizing problems will occur. In this embodiment, when the transport reference is the center reference, separation is performed.
The notch like the part 7c becomes one set and two pieces,
There is no problem when the standard is one side. (Second Embodiment) Next, referring to FIG.
The second embodiment will be described in detail. Same as the first embodiment
One function, members of the same shape will be described again using the same symbols.
Description is omitted. In the second embodiment, in order to prevent paper waving,
A fixing device using a fixing roller having tapered portions at both ends.
In, for the separation of the tapered part where the separability decreases,
In addition to increasing the separation angle, the distance to the fixing roller
The separation guide is also provided with a tapered part to keep the
It is. FIG. 4 is an oblique view showing the end of the fixing roller and its vicinity.
FIG. In the figure, reference numeral 21 denotes an aluminum fixing row.
And 21a (not shown) and 21b are tapes provided at the ends.
In the paper section, the paper edge with the maximum paper passing width conveys this tapered part.
You. Reference numeral 20 denotes a separation guide, 20a (not shown), 2
0c is engaged with the tapered portions 21a and 21b of the fixing roller.
Separation section with taper, 20b is B5 / EXE size
Separation section for separating the paper edge, 20d other separation section
And 20'e and 20'f are mounting pins for the spacer 22.
It is. 23 (not shown) and 23 'are fixing roller bearings 2
2 (not shown), 22 'is a spacer 22'a (not shown)
) And 22 are holes 2 to be fitted with the mounting pins of the separation guide.
Reference numeral 2'c denotes an abutting surface that engages with the fixing roller 21. The waving generated at the edge of the paper is a measure against wrinkles.
And the pressure roller provided on the fixing roller
Paper generated by the force generated by the pressure applied from
Is a variant of The pressure applied from the pressure roller 3 varies in the axial direction.
The pressure roller 3 itself is not uniform but receives from the fixing roller
Due to deformation due to reaction force, the pressure at the end against the center is
high. Even under the same force, the paper is more at the edge than at the center.
Is weaker, so the end face parallel to the transport direction is wavy.
Deform to. The taper provided on the fixing roller 21 is located at the center.
Opposite the direction in which the paper is spread outwards
Axial direction acting on the paper edge by acting in the direction of pushing inward
To counteract the power of
Wear. On the other hand, the end of the paper should be along the tapered portions 21a and 21b.
Bends in the opposite direction, causing close proximity to the fixing roller and degraded separation
You. Therefore, this embodiment is similar to the first embodiment in that
The separation angle between the separation portions 20a (not shown) and 20c
Set larger than the separation part 20d to separate and fix
The same distance so as not to separate the distance from the roller 21
For example, it is inclined so as to keep it at 0.5 mm. In addition,
Sensor 22 (not shown), butting portion 22c of 22 '(not shown)
) And 22'c directly contact the fixing roller outside the paper passing area.
And fixing roller bearings 23 (not shown), 23 'external dimensions
Eliminates tolerances and allows for more accurate fixing rollers and separation guides.
It is a realization of distance. (Third Embodiment) Next, referring to FIG.
The third embodiment will be described in detail. Same as the first embodiment
One function, members of the same shape will be described again using the same symbols.
Description is omitted. The third embodiment has tapered portions at both ends.
In the fixing device using the fixing roller 21, the separation property is poor.
The taper part separation method is changed to a nail separation method.
You. FIG. 5 is a front view showing the structure of the fixing device.
Are separation guides, and 31a and 31e are separation claws 32 and 32 '.
The support portions 31b, 31c and 31d are used to separate the paper edges.
Separation section with a large separation angle, 31f is inside the paper
This is a separation section having a small separation angle for separating. 3
2, 32 'are separation claws, and 32a, 32'a are separation claw rotations.
The shaft is rotatably supported by the support portions 31a and 31e.
The illustrated claw springs 33 and 33 ′ cause the claw tip to be fixed to the fixing roller 2.
It is attached so as to be in pressure contact with 1. Separating claw 3
The axial positions of 2a and 32'a are the ends of the maximum paper passing size.
For example, about 5 to 10 mm. In this embodiment, the tapered portion 21 of the fixing roller 21 is used.
The nail separation method is applied only to the parts where
The fusing roller that has been used to prevent waving
The specified separation performance can be obtained. Also the paper edge
Since the separation angle is small, the curl at the end is smaller.
High and free of curl and wavy deformation
It can discharge high quality paper. In the nail separation method, the nail directly contacts the fixing roller.
To damage the fuser roller,
ー) adheres to the tip of the nail and this adheres to the paper.
Image quality and poor durability.
There is a title. However, in this embodiment, 5 to 10 m from the paper edge
Because the claw was provided at the position of m, the fixing roller was damaged.
Even if it is not printed at this position,
Since the degree is very small, the influence on the image is small. Again
For the same reason, the developer does not adhere much to the tip of the nail.
The frequency with which the developer material attached to the edge adheres to the paper is very low. (Fourth Embodiment) Next, the present invention will be described with reference to FIG.
The fourth embodiment will be described in detail. Same as the first embodiment
One function, members of the same shape will be described again using the same symbols.
Description is omitted. In the fourth embodiment, in order to prevent paper waving,
A fixing device using a fixing roller having tapered portions at both ends.
In, for the separation of the tapered part where the separability decreases,
A member to keep the distance between the fixing roller and the separation guide constant
Has a large separation angle and a tapered part.
A separation guide is provided. Figure 6 shows the fixing roller
It is a perspective view which shows an end part and its vicinity. In the figure, 50 is a separation guide, 50a
(Not shown), 50c is attachment of spacers 51, 51 '
And 50b are for separating the edge of the B5 / EXE size paper.
Separation part, 20d is another separation part, 50'e, 50 '
f is a mounting pin for the spacer 22. 51 (not shown
), 51 ′ are spacers, 51a (not shown), 51 ′
a 'is the mounting pin 50'e, 50'f of the separation guide.
The mating hole 51 ′ c has a protrusion engaging with the fixing roller 21.
The contact surface 51'c is a separation portion. In this embodiment, the fixing roller 21 contacts the fixing roller 21.
The separation angles of the spacers 51, 51 'are large and
Superiority due to the provision of a tapered separation section
With separation ability. The separation section of the separation guide 50 has a separation angle
Boundary between the large 50d part and the small separation angle 50b
Minutes, unlike the previous embodiment, the separation angle changes continuously
Paper is hard to catch on the paper.
The separation performance has also been improved. As described above, the present invention relates to a fixing device.
In the separation of the paper, the part where the edge of the paper is transported and the inside of the paper are transported
2 When using a fixing roller with a taper at both ends
In this case, the part where the taper part engages and the part inside the roller
And the separation conditions were changed. With this configuration, 1 For a portion where the separation conditions are severe, a reliable separation is performed.
Is possible and its area is limited,
Maintenance of conditions and stable production are easy. 2 Because the separation angle can be reduced at the center of the paper,
The tip curl can also be reduced by the rate separation method. 3 In the paper passing area or printing area,
The separation member does not come into contact with the
It is possible to maintain over time. Accordingly, the separation performance of a simple structure
An excellent fixing device can be provided. FIG. 101 is a sectional view of a copying apparatus according to the present invention.
FIG. 102 shows a perspective view. 1 is an apparatus main body, 2 is a plurality of originals D
Document transport unit that transports documents one by one.
Image reading unit for reading the image, 4 from the laser beam printer
The recording unit 5 includes a display unit, input keys, and the like.
The operation unit 6 stores a plurality of sheet materials S and transports them one by one.
Cassette feeder for feeding, 7 is MP (multi-paper) feed
A paper unit 8 is a control unit of the entire apparatus, and 9 is a power supply. An image reading unit 2 is provided on the upper part of the apparatus main body 1.
The image reading unit 2 includes a recording housing 10 that supports the recording unit 4.
And an electrical housing 11 supporting the main body control unit 51;
The support 401 supports the right front of the image reading unit 2.
Is held. Below the image reading section 3, a recording and discharging section 12 is provided.
It has a so-called internal discharge configuration,
The paper unit 12 and the image reading unit 2 are provided on the bottom provided in the image reading unit 2.
It is partitioned by a plate 402. (Reader) A document table is provided on the upper surface of the image reading section 2.
Glass 501, drifting glass 502, jump table 50
3 are provided. An original pressing plate 504 is provided above the image reading unit 2.
Document feeder unit 2 provided with
There is no hinge provided. The image reading section 2 includes image reading means.
Contact image sensor 506, carriage 507, guy
Shaft 508, timing belt 509, drive pool
510, image processing relay board 511, optional
Document size detection sensor 512 can be arranged as
Noh. The contact type image sensor 506 is not shown.
One-dimensional photoelectric conversion element and Selfoc lens (trademark)
506a and selfoc lens (trademark) 506a
A light source 506b is arranged on the side,
c. The contact type image sensor 506 is a carriage
507 is elastically supported by a spring (not shown).
And is placed on the platen glass 501.
Make sure that the distance to the placed document D does not deviate from the depth of focus.
The distance is kept constant. The carriage 507 has a reading drive motor 513
Connected to the timing belt 509 driven by
One-dimensional photoelectric conversion element in the contact type image sensor 506
Image along guide shaft 508 perpendicular to child 506d
It reciprocates in the reading unit 2. The position of the contact type image sensor 506 is
Based on the detection timing of the camera position sensor 514
Is controlled by the rotation frequency and rotation time of the motor
2 Document D is placed on platen glass 501.
The document feeder 2 provided with the document pressure plate 504 is closed.
Document size is detected at the timing of the specified opening and closing angle.
The size of the document is detected by the sensor 512. The copy start key 601a is pressed.
Then, the detected document size and the input
Recording paper of a predetermined size is selected according to the magnification information.
Then, the sheet feeding operation of the sheet material S is started. Suitable size
If no recording paper exists, the display section 602 indicates that.
indicate. After the start key 601a is pressed, the shade
Scanning from the leading edge of the original,
A / D conversion is performed by the provided image processing relay board 551,
It is sent to the image processing unit 52 of the apparatus main body. Close contact image
The sensor 506 and the image processing relay board 551 are
It is electrically connected by a rat cable. When scanning is completed, the reading drive motor 513 is reversed.
The standby position where the original image sensor 506 is rotated to rotate.
Return to (DF) Configuration of Document Conveying Unit 2 and
The operation is as follows. Document D is transported to document table 21
That can slide in the direction perpendicular to the
A rider 21a is provided, and the slider 21a is
Therefore, both sides of the document D stacked on the document table 21
Can be aligned. When document D is loaded on document loading table 21,
The presence of the original is detected by the original detection sensor 21b, and the length is detected.
Detection is performed based on the amount of movement of the sensor 21c and the slider 21a.
The width of the original is detected by the width detection sensor 21d.
The information is passed to the main body control unit 51 in the apparatus main body 1 and the operation is performed.
Write a predetermined size according to the magnification entered from the work unit 5.
Recording paper is selected. There is no paper of the appropriate size
If this is the case, this is displayed on the display unit 602. The original detection sensor 21b detects the original.
If not, the original platen glass 501 on the stationary reading side
Judge that the original is placed on top
The sensor 506 scans the original table glass 501 side. The start key 601a on the operation unit 5 is pressed.
When the contact type image sensor 506 is
The document table glass 50 with the jump table 503 interposed.
Moves below the reading glass 502 on the opposite side of 1 and stops
I do. A plurality of documents stacked on the document table 21
D by the separation roller 22b pressed against the separation pad 22a.
Separated sheet by sheet, and U-turn
The paper is conveyed by the paper passing path 22d. Further, if the original D is the original leading edge detection sensor 22f
, The first image reading unit is fed by the feed roller 22e or the like.
515, and the leading edge of the original is contact image sensor 50
6 when the image reading position reaches the stopped image reading position.
When the image starts to be scanned, the image signal is transmitted to the image processing relay board 551.
A / D conversion is performed and sent to the image processing unit 52 of the apparatus main body 1.
Can be In the first document reading section 515, the document D
Close to reading glass 502 by manuscript holding roller 22g
Then, the image information of the document D is read. The original D is scanned and read on the jump table 503.
Document 502 is picked up from the upper surface of the
Are discharged onto the document discharge tray 23 through All originals loaded on the original loading table 21
Has been read, and the original detection sensor 21b indicates "no original".
Upon detection, the contact type image sensor 506 returns to the original standby state.
Return to position. (Cassette) The cassette paper feeding section 6 is a
A feeder unit 301 detachable from the body 1 and a feeder
A paper cassette 302 detachable from the
Is done. The feeder section 301 supports the apparatus main body 1 from below.
It has a function as a structure for holding
The feeder can be connected to the lower part of the apparatus main body 1.
You. The paper cassette 302 picks up a bundle of recording paper.
A cassette middle plate 304 that urges the roller 303;
Coupling sheet of recording paper in cooperation with backup roller 303
Separation claw 305 for limiting the number, and width direction of the recording paper bundle
Regulating plate 305 for regulating the trailing edge of the recording paper bundle
And a rear end regulating plate 307. The sheet material S can be moved according to the paper size.
The side end surface is regulated by the side regulating plate 305
Control prevents skew and non-feeding.
It has become. The image is loaded on the paper cassette 302.
It is recorded on the lower surface side of the sheet material S. Also, the sheet material S
The presence or absence is detected by the cassette sensor 308. Also,
In the present embodiment, the above-described paper feed cassette 302 has about 500
It is possible to stack two sheet materials,
Can be pulled out to the front (front loading method)
Is configured. The sheet cassette 302 has a seed
Various sheet sizes (for example, A3, A4, A5, B4, B
(7 types of 5, 5, letter and legal) sheets can be loaded
It has become. Sheets loaded on paper feed cassette 302
S: the cassette middle plate 304 is moved upward by the middle plate spring 309
And pressed against the semicircular pickup roller 303.
And the separation claw 3 located on the tip side of the cassette middle plate 304.
It is squeezed out in cooperation with 05. The main body control section 51 in the main body 1
When a trigger to squeeze the material S is applied,
LA 303 receives power from a motor (not shown)
Sea power is connected by an electromagnetic clutch (not shown).
The material S is tied up. The recording paper multi-fed by squeezing is fed to the paper feed roller 3
10a and the retard roller 310b
It is. The retry sensor is located downstream of the paper feed roller 310a.
312 and a pull-out roller 313 are provided.
A trigger to drive the backup roller 303
And the sheet material S is detected by the retry sensor 3 even after a predetermined time.
If not detected in step 12, the control unit
A trigger for rotating the roller 303 is issued to generate the sheet material S.
Perform the squeezing operation. The separated sheet material S is registered after a predetermined time.
The tip is detected by the strike sensor 209. Paper feeding starts
Within a predetermined time after the registration, the registration sensor
If the tip of the material S is not detected, it is determined that a jam has occurred and the operation is performed.
The display is performed on the unit 5. Further, the above-described cassette sheet feeding section 6 and the apparatus
Although it has been described that the body 1 is detachable,
The second and subsequent cassettes having the same configuration as the
The paper feeding unit 6 can be further added. (MP) MP (multi-paper) paper feed unit 7
Are MP feed rollers 201, MP separation pads 202, M
P middle plate 203, MP tray 204, MP extension tray 20
5, MP middle leaf spring (not shown), sheet regulating plate 206
Have. The conveyance of the sheet material S from the MP sheet feeding section 7 is also performed.
Is possible, and a plurality of sheet materials S are placed on the MP tray 204.
Placed, MP feed roller 201 and separation pad 202 minutes
In cooperation with the release pad 202, the resist row inside the main body is
Conveyed to the pair of cars 210. At the time of using the MP sheet feeding unit 7, the normal size
The MP tray 204 that can be opened and closed
Of a size that cannot be stacked on the MP tray 204
Pull out MP extension tray 205 for recording paper
Causes the trailing edge of the recording paper to protrude from the MP tray 204
To prevent it from sagging. Also, M
The P middle plate 203 is urged upward by the MP middle plate spring.
However, while the MP plate 203 is in the standby state,
(Not shown), the sheet material S
It can be loaded on the MP middle plate 203. The MP feed from the main controller 51 of the apparatus main body 1
When a signal to start the operation is output, the cam (illustrated
(Not shown) is rotated, and the MP plate 203 is pushed down to release the load.
The pressed sheet material S is pressed against a semicircular MP feed roller 201.
In contact with each other, and in a friction piece separation manner by the MP separation pad 202.
Each sheet is separated and transported. Separated sheet material S
Is applied to the MP feed roller 201 and the MP separation pad 202.
The press-contact conveyance is further continued, and
They merge and are transferred to the registration roller pair 210. Within a predetermined time from the start of sheet feeding,
When the strike sensor 209 detects the leading end of the sheet material S
Means that the separated sheet material S is the MP sheet feeding roller 201
And the MP separation pad 202 keeps
The stroller pair 210 is guided to the press-contact nip portion N. Within a predetermined time from the start of sheet feeding,
When the strike sensor 209 does not detect the leading end of the sheet material S
Is determined to be a jam and is displayed on the operation unit 5.
I have. (Registration) The registration roller pair 210 is
The leading end of the sheet material S is
When it reaches the pump section, it is controlled to stop rotation.
You. The registrar whose leading end of the sheet material S is in a rotation stopped state
Abutting against the press-contact nip of the roller pair 210,
After that, pull the MP feed roller 201 or the cassette side.
The sheet material S is fed by the punching roller 313.
Then, a certain degree of bending loop is formed in the sheet material S.
Therefore, the tip side of the sheet material S is caused by the reaction force of the bending loop.
Being parallelized following the nip line of the pressure nip
Thus, the skew of the sheet material S is corrected. (Image Forming Unit) The image forming unit 13 includes an image forming unit.
14 and a fixing device 15. The imaging unit 14 is a laser scanner.
Cartridge 701 and toner-integrated process cartridge 70
2 and a transfer roller 703,
The inside of the ridge 702 is a photosensitive drum 702a and a charging roller 70.
2b, developing sleeve 702c, cleaning blade 7
02d, toner hopper 702e, cartridge housing 7
02f, and the process cartridge 702 is
It can be attached and detached to the left toward it. The laser scanner 701 is a laser beam
Oscillator 701a, polygon mirror 701b, folding
A mirror 701c and a laser beam oscillator 7
01a, and outputs a modulation signal from the polygon mirror 701b.
Irradiates the photosensitive drum 702a with scanning light, thereby turning it back.
The scanning light is reflected by the mirror 701c. (CRG) The photosensitive drum 702a
Charging roller 702b, developing sleeve 702c, cleaner
Of the recording cartridge 702 together with the printing blade 702d.
It is integrated into the inside of the
It is removable. The surface of the photosensitive drum 702a is a belt
Is uniformly charged by the electric roller 702b, and
Scanning light is emitted from the user beam oscillator 701a
As a result, a latent image is formed, and the latent image is
02c so as to be visualized by the toner supplied from
Has become. (Fixing) Sheet Conveyance Downstream of Image Forming Unit 14
In the path, a heat fixing device 704 and a first paper discharge roller 451 are provided.
Are located. The heat fixing device 704 includes a heat fixing roller 704a,
Pressing roller 704b, heat fixing roller 704b
Pressure spring (not shown) for urging in the direction of
A fixing release lever 704c for releasing the urging pressure of the roller;
It consists of a fixing frame 704d that supports
A heater 704e is provided inside the roller 704a,
Temperature detection sensor in contact with the surface of heat fixing roller 704a
(Not shown) is provided. Based on the signal of the registration sensor 209,
The registration roller pair 210 is driven at a fixed timing
And the sheet material S is imaged by the registration roller pair 210.
14. The predetermined timing is defined as
Of the toner image formed on the sheet 702a and the sheet material S
The timing is such that the tips match. The sheet material S is sensed by the transfer roller 703.
The toner image formed on the surface of the optical drum 702a is transferred.
After being transported along the sheet transport section 705,
After the toner image is fixed by the fixing device 704, the first
Discharge to the first discharge tray 452 by the discharge roller 451
Is done. A fan duct is provided behind the fixing unit 15.
And radiate the heat inside the device to the outside with a cooling fan (not shown).
ing. (Cover) The main body 1 has a cartridge cover.
A bar 212 is provided so as to be openable and closable.
04 and the cartridge cover 212 are opened.
The recording cartridge 702 is pulled out of the apparatus main body 1 and replaced.
I can do it. In addition, cartridge cover 2
12 is equipped with an interlock mechanism.
The cartridge cover 212 is open or the recording cartridge 7
If 02 is not set in the main unit 1, the recording device
The main body 1 does not operate. If a paper jam occurs during recording,
Cover 314, cartridge cover 212,
Stay inside by opening any of the bars 453
Sheet material S can be taken out
ing. (Sheet Discharge) The sheet material S after fixing is first inverted.
With the recorded image surface down by the path 454, three rows
The first discharge roller 451 is a first discharge roller.
The sheet is discharged to the paper tray 452. Three first paper ejection rollers
451, one outside the first inversion path 454 and inside
There are two provided, the inner two rollers are the outer one
Rollers are urged. Sheet material S is outside
Undergoes reverse curl correction along the outer circumference of the roller. The sheet material S is large on the first discharge tray 452.
Amount, and is detected by the first full load detection sensor 454.
Then, the full load is displayed on the operation unit 5 and the recording operation is stopped. Further, above the first discharge tray 452
Optional second output tray 457 can be provided
Noh. The sheet material S after fixing is transferred to the second discharge tray 4.
57, the sheet is discharged by the discharge flapper 456.
The conveyance direction of the material S is changed, and the second reversing path 458 and the second
The sheet is discharged to the second sheet discharge tray via the sheet discharge roller 459.
You. The second discharge roller 459 and the second full load detection sensor
Each of the first paper discharge roller 451 and the first full load detection sensor
The configuration is the same as that of the antenna 454. The second discharge tray 457 is mounted.
When the first discharge tray 452 is full
Without stopping the recording operation at the second discharge tray 457.
It is also possible to discharge the material S. In addition to the copy function, this apparatus has a facsimile function.
It has a similiar transmission / reception function and network print function
The first discharge tray 452 and the second discharge tray 45
7 can be selectively switched. (Control system) The figure uses the LBP in the present invention.
FIG. 3 is a block diagram of a main body control unit 51 of the copying machine used. Figure
, 53 is a CPU for controlling the entire copying machine;
Stores a control program for the PU 53a and the MPU 53a and the like.
ROM 53b, work areas and images for various data processing
RAM 53b used as a temporary storage of information,
The image processing unit 52 or the like that performs image scaling, resolution conversion, etc.
It is configured. The CPU 53 has a well-known configuration.
Rendering, clock function, etc. are provided.
One-touch key destination information, software switch information, etc.
The area for storing important system setting information is battery
Backup protects against accidents such as power outages
ing. The operation unit 5 includes a numeric keypad 601c and a function key.
Key 601d, one-touch key 601e, start
Key 601a, stop key 601b, energy saver
And various key switches such as a key 601f. display
A unit 602 is an LCD 602a for displaying various messages.
And multiple LEDs 602b, copier mode and facsimile
From the mode switching key 601g for switching the transmission mode.
You. The image reading section 3 is a reading drive such as a reading motor.
A control unit 54, a reading sensor 55 for reading an image,
Image shading, binarization, edge enhancement, smoothing
Image processing unit 52 for performing jigging, etc., various types for performing document detection, etc.
It consists of a sensor 56. The recording section 4 is a recording drive control section such as a recording motor.
57, control of laser scanner and electrophotographic process
Recording unit 58 to perform, smoothing of images to be recorded, etc.
The image processing unit 52 performs various operations such as detecting recording paper and the like.
(62). This apparatus functions as a facsimile transceiver.
In this case, the control system consists of the following. Outgoing and incoming calls
The communication control unit 63 that performs call, image data encoding, etc.
It has a connecting part 59 made of DEM, NCU, etc.
9, a communication network 59a and a handset 59b are connected.
You. The external interface 60 receives data directly from the CPU 53.
Interface for sending and receiving data, such as RS2
32C, SCSI, LAN, USB, IEEE1394,
Computers and peripherals outside the device through infrared and other lines
By connecting to the device, the device can be scanned by an external computer.
Use as a printer or external peripheral device
Function as a host. The HDD 61 is a large-capacity nonvolatile memory.
Used for storing image information.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an example of a film heating and fixing apparatus embodying the present invention. FIG. 2 is an example of a film heating and fixing apparatus embodying the present invention. FIG. 3 is a configuration of a laser beam printer to which the present invention is applied. FIG. 4 is a correlation diagram showing an example of a rise in pressure roller temperature when the pressure amount is 5 kg and 7 kg. FIG. 5 is a view showing a phenomenon of hot offset. FIG. 6 is a diagram showing an increase and a decrease in a pressurizing amount during printing.

Claims (1)

Claims: 1. A film is brought into contact with a heating body and moved, and a recording material is brought into close contact with a surface of the film opposite to the heating body side, and the recording material is moved and passed together with the film. Thus, in a fixing device that applies heat energy, a pressing amount of a pressing member that forms a nip with a film is variably provided, and a unit that controls the pressing amount is provided.
And by the means, the pressurizing amount is increased just before the recording material enters the nip, the pressurizing amount is reduced when the recording material enters the nip, and the pressurizing amount is reduced when the recording material exits the nip. A fixing device that performs control to further reduce the fixing device.