JP3525682B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to an electrophotographic system.
Image forming equipment used for linters and copiers
You. [0002] 2. Description of the Related Art Conventionally, a toner image formed on a photosensitive member is
Primary transfer electrostatically on the intermediary transfer member, then transfer on the intermediate transfer member
Intermediate transfer body superimposed with the toner image
The recording material is heated and pressed with a heating and pressing roll.
While transferring the toner image on the intermediate transfer body onto the recording material,
An image type that adopts the so-called simultaneous transfer and fixing method for fixing
An apparatus is known. This transfer-fixing simultaneous image type
The image forming apparatus adopts the electrostatic transfer method for the secondary transfer.
Higher image quality with higher transfer efficiency and better color balance than devices
Has the advantage of obtaining
Commonly used. However, this simultaneous transfer and fixing method
When an image is formed on both sides of a recording material using an image forming apparatus,
After forming the image on the first surface of the recording material, forming the image on the second surface
When performing the transfer, the transferred toner image on the first surface is
When the image quality of the first surface is degraded by heating and pressing again by the
There is a problem. As a solution to this problem, Japanese Patent Publication No.
Japanese Patent No. 29217 discloses two intermediate transfer units.
First, a toner image for the first surface is formed on the photoreceptor.
This is transferred to the first intermediate transfer unit, and then on the photoreceptor.
Forming a toner image for the second surface on the second intermediate transfer member
Unit, and finally these two intermediate transfer unit
The paper is pressed against each other with the recording material
The toner image on each intermediate transfer unit on both sides of the recording material.
A double-sided image forming method for transferring images at the same time is disclosed. This
In the two-sided image forming method, the two-sided image is simultaneously transferred and fixed.
Therefore, the image on the first surface is not heated and pressed again.
It is possible to prevent image deterioration. [0004] However, the above two-sided image
The image forming apparatus adopting the image forming method has two intermediate transfers.
Since the body unit needs to be equipped, the image forming
The problem that the size of the body increases, which leads to an increase in cost
Problem arises. Realizing a small and low-cost image forming apparatus
In order to achieve this, one intermediate transfer unit
It is desirable that an image can be formed on the surface. [0005] By the way, transfer and fixing using an intermediate transfer member are performed.
When double-sided image formation is performed by the
The image already formed on the first surface of the material is heated and pressed again
Image quality degradation caused by
Appear in shape. FIG. 11 shows an image of a conventional simultaneous transfer and fixing system.
Image gloss when double-sided image formation is performed
It is a graph which shows a mode of a fall. FIG. 11 shows an image formation by simultaneous transfer and fixing method.
When an image is formed on both sides of the recording material by the apparatus, 1
Of the image of the first side obtained by forming the image only on the side
The image gloss and the image obtained by image formation on the first side are the second side
1st image after heating and pressurizing again by image formation
The difference from the image gloss is shown. In the graph of FIG.
Shows the measurement results of the glossiness of the image for two types of recording materials
In the recording material A, the glossiness of the image on the first side is
Was about 97 gloss, but the image formation on the second side
The glossiness of the image is reduced to about 50 gloss.
The glossiness of the image on the first side was about 62 gloss
Has gloss of about 28 gloss due to image formation on the second side
Has declined. FIG. 12 shows an image of a conventional simultaneous transfer and fixing system.
Image on the first side when double-sided image formation is performed by the image forming apparatus
FIG. 3 is a cross-sectional view of a toner image during image formation. Simultaneous transfer and fixing
In the image forming apparatus of (1), as shown in FIG.
In the primary transfer process, the toner
A toner image 2 is formed by the particles, and then, FIG.
As shown in (b), the toner image 2 is
The intermediate transfer body 1 and the recording material 3 sandwiched therebetween are heated and pressed by a pressing member.
As shown in FIG. 12 (c).
Thus, the fixed toner image is formed on the surface 3a of the recording material 3 after the transfer and fixing.
2a is formed. This fixed toner image 2a has smoothness
It is heated and pressed in a state in which it is in close contact with the surface of the intermediate transfer member 1
A surface with high smoothness due to melting of the surface
The glossiness of the image is high because it is formed as a toner image.
No. However, as shown in FIG.
Inside 2a, a gap depending on the toner particle shape before dissolution
G remains. FIG. 13 shows an image of a conventional simultaneous transfer and fixing system.
Image on the second side when double-sided image formation is performed by the image forming apparatus
FIG. 4 is a schematic diagram illustrating a state of a toner image during image formation. FIG.
As shown in (a), the surface 3a is formed by the image formation on the first surface.
The recording material 3 on which the fixed toner image 2a is formed is shown in FIG.
As shown in (b), a toner image has not been formed yet
With the back surface 3b facing the heating and pressing roller 4, the heating and pressing roller
Rollers 4 and 5 are supplied to the nip portion. On the other hand, the recording material 3
In accordance with the timing supplied to the nip,
The intermediate transfer body 1 moving in the direction
And reaches the nip, where the intermediate rotation occurs.
The toner image 2 on the second surface on the photoreceptor 1
5, heated and pressurized, the back surface of the recording material 3
3b is transferred and fixed. The recording material 3
The first fixed toner image 2a on the front surface 3a is also heated and pressed.
The rollers 4 and 5 receive the heat and pressure again. As a result,
As shown in FIG. 13C, one surface on the surface 3a of the recording material 3
The smooth surface of the fixed toner image 2a of the eyes is re-melted,
The gap G between the toner particles hidden under the surface appears on the surface.
As a result, dents P and cracks are formed on the surface, and the surface becomes uneven.
The glossiness decreases. The present invention has been made in consideration of the above circumstances, and has been made in consideration of the above circumstances.
High gloss image on both sides even if image is formed on the side
To provide an image forming apparatus capable of forming
Aim. [0010] [Means for Solving the Problems] [0011] [0012]UpThe present invention that achieves the above objectsPaintingImage forming equipment
The installation isOnce the toner image is formed and the formed toner image is
After being transferred onto the photocopying body, it is conveyed by the recording material conveying means and
Heating on the recording medium superimposed on the intermediate transfer member;
Transferred and fixed by pressurization and cooled the toner image
After the recording material is peeled off from the intermediate transfer member, recording is performed.
Image form that forms an image consisting of a toner image fixed on a material
In the production equipment,The recording material conveying means is,RecordBoth sides of recording material
When it is instructed to form an image on the
Only the recording material on which an image is formed,
Roll on the above-mentioned intermediate transfer member so that it is in contact with the intermediate transfer member.
The image corresponding to the image formed on the back surface of the recording material
Superimposed on the above intermediate transfer body so that the toner image is sandwiched
And, furthermore,Surface roughness less than toner particles
Having a belt-shaped member that can freely contact and separate from the intermediate transfer member,Record
When it is instructed to form images on both sides of the recording material
After the image formation on the surface is completed,
The heating and pressurizing member
Heated byandOn the recording material surface after pressurizationthe aboveElement
Formed on the surface of the recording material by contacting
Having a toner image smoothing means for smoothing the surface of
It is characterized by. [0013] [0014] DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
explain. FIG. 1 shows a first embodiment of the image forming apparatus of the present invention.
It is a schematic structure figure showing a form. This embodiment corresponds to the present invention.
The first image forming apparatus is transferred and fixed using an intermediate transfer member.
Time-based digital color printer
You. The image forming apparatus 100 is designed to print on both sides of a recording material.
Double-sided mode, which forms an image on one side, and
It has two operation modes, one-sided mode for performing image formation.
To analyze the input data from the outside and
A mode determination unit 20 that determines whether a command has been issued,
Image forming apparatus 10 based on the determination result of mode determination unit 20
0 indicates the operation mode of the duplex mode or the simplex mode.
Process control unit that controls whether to operate based on the mode
21 and the surface of the recording material when the duplex mode is specified.
And a recording material reversing device 30 for reversing the back.
You. The recording material reversing device 30 includes transport direction switches 31 and 3
2. Recording material reversing unit 33 and recording material transport roll 34
a, 34b, etc. The image forming apparatus 100 shown in FIG.
(Personal computer) Image data sent from 7
Is input, the mode determination unit 20 performs
That is, the image data input from the PC 7 to the image forming apparatus 100.
By analyzing the control signals contained in the data,
Indicate which operation mode, one-sided or one-sided,
Is determined, and the result is sent to the process control unit 21.
introduce. The process control unit 21
The processing of each unit in the image forming apparatus 100 is performed based on the determination result.
Control in accordance with the designated operation mode. This implementation
Control unit 21 in the embodiment has a
Toner amount control for controlling the amount of toner attached to the electrostatic latent image
A circuit 22 is provided. The input image data is IPS (image
Processing system) 8
It is sent to the knits 9a, 9b, 9c, 9d. Laser Dora
From the units 9a, 9b, 9c, 9d
Exposure corresponding to each color of black, yellow, magenta, cyan
Light is output. Exposure light is transmitted through mirrors 10a, 10b, 10
photoconductor drum rotating in the direction of arrow A via
Irradiation is performed on the beams 6a, 6b, 6c and 6d. The photosensitive drums 6a, 6b, 6c, 6d
Prior to the formation of the electrostatic latent image, the photosensitive drums 6a, 6b,
Charger 11 for uniformly charging the surfaces of 6c and 6d
a, 11b, 11c, and 11d are provided.
By the electric chargers 11a, 11b, 11c, 11d.
On the charged photosensitive drums 6a, 6b, 6c, 6d
And the laser driver units 9a, 9b, 9c, 9d
From the photosensitive drums 6a, 6b, 6
c, 6d on black, yellow, magenta, cyan
Each corresponding electrostatic latent image is formed. Here, the mode is determined by the mode determination section 20.
Operation mode is either double-sided mode or single-sided mode
Depending on the toner amount control circuit 22, the toner amount control circuit 22
The amount of toner to be controlled is controlled. Details of toner amount control
Will be described later. On the photosensitive drums 6a, 6b, 6c, 6d
The black, yellow, magenta, and cyan colors
The corresponding electrostatic latent image is a photoconductor at the developing position D.
Approaching or touching the drums 6a, 6b, 6c, 6d
Developing roll for transporting toner to developing position D
Corresponds to 12a, 12b, 12c, 12d
Color toner is applied on each photosensitive drum.
A toner image corresponding to each color is formed. Photoconductor
Toner images formed on drums 6a, 6b, 6c, 6d
Indicates a core located at the primary transfer position T1 of each photosensitive drum.
By rotron transfer units 14a, 14b, 14c, 14d
In addition, the proximity to each photosensitive drum at the primary transfer position T1
Or circulate in the direction of arrow B placed in contact with
Primary so as to be superimposed on the
Is transferred to form a multicolor toner image on the intermediate transfer body 1.
You. On the photosensitive drums 6a, 6b, 6c, 6d
Downstream of the primary transfer position T1 are cleaners 13a, 13
b, 13c and 13d are arranged, and the end of the primary transfer
Remaining on the surfaces of the photosensitive drums 6a, 6b, 6c, 6d
Removed toner. Multicolor toner image formed on intermediate transfer body 1
Is supported by the support rolls 17a, 17b, 17c and 17d.
And carried on the intermediate transfer body 1 circulating in the direction of arrow B.
And a nip is formed by a pair of heating and pressing rolls 4 and 5.
To the heating / pressing position T2. On intermediate transfer member 1
Is transferred to the heating and pressing position T2.
The recording material transport roll 19
Recording material 3 is supplied from paper tray 18 to heating / pressing position T2
Is done. In a state where the multicolor toner image is overlaid
The intermediary transfer body 1 and the recording material 3 are heated and pressed at the heating and pressing position T2.
Heated and pressed by hot press rolls 4 and 5
Thus, the multicolor toner image on the intermediate transfer member 1 is transferred onto the recording material 3.
And is established. The surface is multicolored by the heating and pressing rolls 4 and 5.
The recording material 3 onto which the toner image has been transferred and fixed is placed on a support roll 17b.
It is further separated from the intermediate transfer body 1. Where the operation mode
If the instruction from the determination unit 20 is the one-sided mode,
The material 3 is discharged by the discharge roller 15 by the transfer direction switch 31.
Although discharged to the outside of the image forming apparatus, the operation mode determination unit 20
If the instruction is in the duplex mode, the recording material 3
The recording material is conveyed toward the material reversing device 30 and
By switching back, the front and back of the recording material 3 are inverted.
Recording material transport rolls 34a and 34b, and transport direction
The recording material 3 is temporarily stored in the tray 18 by the switch 32.
Further, the heating / pressing position is
The sheet is transported to T2, and image formation on the second surface is performed. Multicolor
The intermediate transfer body 1 after transferring the toner image onto the recording material 3 is a bell.
The surface is cleaned by the cleaner 16 and again
The photosensitive drum circulates toward the primary transfer position T1.
You. In this embodiment, the IPS 8 and the
The driver units 9a, 9b, 9c, 9d, mirror
10a, 10b, 10c, 10d, and charged charge
The keys 11a, 11b, 11c and 11d are the electrostatic
This corresponds to a latent image forming unit, and is used in the present embodiment.
Developing rolls 12a, 12b, 12c, and 12d according to the present invention.
In this embodiment.
Rolls 12a, 12b, 12c, 12d and
And a predetermined distance between each of these developing rolls and each photosensitive drum.
A power source (not shown) for applying a developing bias
This embodiment corresponds to a toner image forming means referred to in the present embodiment.
Transfer devices 14a, 14b, 14c in the state
14d corresponds to the primary transfer means in the present invention.
The heating and pressing rolls 4 and 5 in the present embodiment are
It corresponds to the heating and pressing member of the transfer fixing means described above.
The support roll 17b according to the present embodiment is different from the present invention.
It corresponds to a peeling means, and in this embodiment
The recording material transport roll 19 and the recording material reversing device 30
This is equivalent to the recording material conveying means mentioned in
The mode determining unit 20 in the embodiment is a determining means according to the present invention.
And the process system according to the present embodiment.
The toner amount control circuit 22 provided in the control unit 21 according to the present invention
This corresponds to the toner amount control means. Next, the toner amount control in this embodiment will be described.
explain about. FIG. 2 shows a first embodiment of the present invention.
4 is a flowchart of an image forming process in the present embodiment. As shown in FIG.
When image data is input to this image forming apparatus,
Mode determination unit 20 (see FIG. 1) is a double-sided mode, a single-sided mode.
It is determined which operation mode of
(Step S01) The determination result is transmitted to the toner amount control circuit 22.
(See FIG. 1). The toner amount control circuit 22
If the result of the determination is the double-sided mode, the first side
Exposure light intensity when forming an image
Set the exposure light intensity to a “high level” higher than the light intensity.
Setting information of the laser driver units 9a, 9b, 9
c, 9d. Laser driver unit 9a,
9b, 9c and 9d are "high level" based on the setting information.
Exposure light with an exposure light intensity of
A latent image is formed (Step S02). Next, the toner image shape
Each process of formation, primary transfer, and transfix is executed
Step S03). By doing so, the photoconductor
To the electrostatic latent images on the rams 6a, 6b, 6c and 6d.
The first image formed on the surface of the recording material
The image is formed with a larger amount of toner than usual. One side
The recording material having the eye image formed on the surface is supplied to the recording material conveying means.
Front and back so that the back of the recording material contacts the intermediate transfer member
After being reversed, it is temporarily stored in the paper tray 18 (see FIG. 1).
(Steps S04 and S05). Next, the second side
Each process of image formation is started. Toner amount control circuit
Reference numeral 22 denotes the exposure light intensity when performing image formation on the second side.
Exposure light intensity of `` normal level '' and set information
Transmit to driver units 9a, 9b, 9c, 9d
You. Laser driver units 9a, 9b, 9c, 9d
Is the “normal level” of the exposure light intensity based on the setting information.
Form an electrostatic latent image by irradiating each photosensitive drum with exposure light
(Step S06). Next, toner image formation, primary transfer, transfer
Each process of copying and fixing is sequentially started (step S0).
7). Here, when the transfer fixing process starts
The recording material transporting unit moves onto the intermediate transfer
Equivalent to the second image formed on the back of the recorded recording material
Superimposed on the intermediate transfer body so that the toner image
To the heating / pressing position T2. Thus, the back of the recording material
That the image of the second side was formed on one side and the image was formed on both sides
The recording material is discharged out of the machine by discharge rollers 15 (see FIG. 1).
(Step S08). On the other hand, mode determination in step S01
If the result of the determination is in one-sided mode, the toner amount control
The circuit 22 sets the exposure light intensity to the “normal level” exposure light intensity.
And set the setting information to the laser driver unit 9
a, 9b, 9c, 9d. Laser driver
The knits 9a, 9b, 9c, 9d are based on the setting information.
Exposure light of "normal level" exposure light intensity is applied to each photosensitive drum.
To form an electrostatic latent image (step S09). Next
The toner image formation, primary transfer, and transfer fixing processes are
Next, it is executed (step S03). Thus, the recording material
An image is formed on one side. The recording material is a discharge roller 15 (see FIG.
1) (see step S10). FIG. 3 shows a conventional image shown as a comparative example.
Toner corresponding to the image formed on both sides by the forming device
FIG. 4 is a top view and a cross-sectional view of an image, and FIG.
Image formed in the duplex mode by
FIG. 3 is a top view and a cross-sectional view of a corresponding toner image. Conventional image
The first side when double-sided image formation is performed by the image forming apparatus
During image formation, as shown in FIG.
1 is a toner image formed with a normal amount of toner.
2 is formed, and this toner image 2 is
(See FIG. 1), the image is transferred and fixed to the surface 3a of the recording material 3.
As shown in FIG. 3B, the surface 3a of the recording material 3 has
The fixed toner image 2a of the surface is formed. Then, intermediate rotation
A toner image on the second surface is formed on the photoreceptor 1, and this toner image
Is transferred and fixed by the heating and pressing rolls 4 and 5, and FIG.
As shown in (c), the second surface is fixed on the back surface 3b of the recording material 3.
The applied toner image 2b is formed. This second side fixing toner
Image 2b is transferred and fixed by heating and pressing rolls 4 and 5.
The surface is molten and shows high gloss. The fixing toner
Although the gap G remains inside the image 2b,
Heating and pressurizing by
The fused high gloss surface remains intact. in addition
On the other hand, the fixing surface of the first surface formed on the surface 3a of the recording material 3
The toner image 2a is heated and pressed by the heating and pressing rolls 4 and 5.
Since the toner image has been received twice, the fixed toner image 2
b had the same high gloss surface as the b
The toner image is re-melted by heating and pressing, and the internal gap G is formed.
As the surface is going to disappear, dents P and cracks are formed on the surface.
Become uneven, and the glossiness decreases. Next, both images are formed by the image forming apparatus of the present embodiment.
An image formed in the plane mode will be described. This embodiment
Form of Image on First Side in Duplex Mode of Image Forming Apparatus
At the time of formation, as shown in FIG.
Is a toner image formed with more toner than normal
2 (the toner image based on the normal toner amount shown in FIG.
2), and the toner is larger than the normal toner amount.
The toner image 2 formed by the heating and pressing rollers 4 and 5 (FIG.
1), is transferred and fixed to the surface 3a of the recording material 3,
As shown in FIG. 4 (b), the first surface
Is formed. Next, the intermediate transfer member
A toner image with a normal toner amount on the second side is formed on
The toner image is transferred and set by the heating and pressing rolls 4 and 5.
After being attached, as shown in FIG.
The fixed toner image 2b on the second side is formed on the surface b. These two sides
The eye-fixed toner image 2b is formed with a normal amount of toner.
And transfer by the heating and pressing rolls 4 and 5
Since the image is received only once, the fixed toner image 2b
Although the gap G remains in the portion, the fixed toner image 2b
The surface is melted by transfer and fixing with heating and pressing rolls 4 and 5.
It shows high gloss. On the other hand, the intermediate transfer member 1
The toner image 2 formed thereon (see FIG. 4A)
The recording material is formed with more toner than the amount of toner.
3 is the first fixed toner image 2a formed on the front surface 3a.
Is the gap between the two heating and pressing by the heating and pressing rolls 4 and 5.
Toner is sufficient to fill the gap G
-The image is completely melted from the inside to the surface, and as a result, FIG.
As shown in (c), no irregularities are generated on the surface.
In addition, the fixed toner image 2a on the first surface shows high glossiness. FIG. 5 shows a first embodiment of the present invention.
When the image is formed by changing the exposure light intensity
6 is a graph showing a change in gloss. As shown in FIG.
This graph shows the exposure light intensity for two types of recording materials A and B.
Gross reduction rate when changing to three levels of high, medium and low
It is a plot of dG / G. First, the image formation of the first side is performed on the surface of the recording material.
The measurement point is sampled from the obtained first image.
To measure the gross of the measurement point and perform the first image formation
The subsequent gloss G is determined. Next, the second side of the recording material
An image is formed. First side of recording material with images formed on both sides
The measurement point is sampled from the image of
The loss was measured to determine the gloss G 'after the second image formation.
You. Next, the gloss G after the first image formation and the second image
From the difference dG (G-G ') from the gloss G' after image formation,
To calculate the gloss reduction rate. Gloss reduction rate = dG / G The image formed on the surface of the recording material by this image forming test
The reduction rate of the image glossiness due to the second transfer and fixing is the exposure light intensity.
How it changes depending on the degree of the degree is required. Figure
As shown in FIG. 5, the exposure light intensity of both recording materials A and B was increased.
The gross reduction rate dG / G decreases as the value increases. this child
From the above, the exposure light intensity is increased to increase the amount of toner adhering to the electrostatic latent image.
The glossiness during double-sided image formation by increasing
It can be seen that can be prevented. In the first embodiment,
Control the electrostatic latent image forming means to change the exposure light intensity.
Means for controlling the amount of toner by
Instead of an image forming apparatus provided with
The developing bias by controlling the toner image forming means.
And a toner amount control means for controlling the toner amount by
The image forming apparatus may include a step. Also, the electrostatic latent image in the first embodiment
By controlling the forming means and changing the exposure light intensity
Image formation with toner amount control means for controlling toner amount
Instead of the device, the toner amount control means controls the primary transfer means.
The amount of toner by controlling the transfer bias
Image formation with toner amount control means adapted to be controlled
It may be a device. Next, a second embodiment of the present invention will be described.
I will tell. This embodiment corresponds to a second image forming apparatus of the present invention.
It is an embodiment about. Image in the second embodiment
The configuration of the forming apparatus is the same as the image of the first embodiment shown in FIG.
It is similar to the configuration of the forming apparatus, and the difference between them is the first.
Provided in the process control unit 21 of the image forming apparatus according to the embodiment.
Second embodiment instead of the used toner amount control circuit 22
Pressure control circuit in the process control unit of the image forming apparatus
The only thing that is provided is a road. This pressure control circuit
Is a heating / pressurizing roller based on the determination result by the mode determination unit 20.
The pressure at the time of transfer and fixing is controlled by the rules 4 and 5. What
The pressure control circuit is a pressure control means according to the present invention.
Is equivalent to FIG. 6 shows a second embodiment of the present invention.
3 is a flowchart of an image forming process. As shown in FIG.
When image data is input to the image forming apparatus, a mode
The operation mode of the duplex mode or the simplex mode is determined by the judgment unit.
Mode is instructed, and
Electrostatic latent image forming means, toner image forming means, and primary transfer means
Formation of an electrostatic latent image on the first side by a step, formation of a toner image, and
Each process of the primary transfer is executed (Step S0)
1). Next, the determination result (step
When S02) is the double-sided mode, the pressing force control circuit
The pressing force at the time of transfer and fixing by the heating and pressing rolls 4 and 5 is
Normal level pressure 4kg / cm^Two Higher pressure 6k
g / cm^Two Control to "high level". Heat and pressure roll
4 and 5 are pressure 6kg / cm^Two To transfer the toner image on the first side
The image is fixed (step S03). This is the first image
The recording material with the image formed on the surface is
Display so that the back side of the recording material faces the intermediate transfer body.
After the back is inverted, the paper is temporarily placed on the paper tray 18 (see FIG. 1).
It is stored (step S04). Next, the second image
Each process of forming is sequentially started (Step S0)
5). When the transfer fixing process starts
At the same time, the recording material conveying means
Toner corresponding to the second image formed on the back surface of the recording material
-Heat the image onto the intermediate transfer member so that the image is
It is transported to the pressure position T2. The pressing force control means is
The pressing force at the time of transfer and fixing by the pressure rolls 4 and 5 is set to “high level”.
6kg / cm^Two To control. Thus,
A second image is formed on the back side of the recording material, and an image is formed on both sides
The discharged recording material is discharged outside the machine by a discharge roller 15 (see FIG. 1).
(Step S06). On the other hand, mode determination in step S02
If the result of (1) is the one-sided mode, the pressing force control circuit
Pressing force by hot press rolls 4 and 5 to "normal level"
Pressure 4kg / cm^Two And the heating and pressing rolls 4 and 5
Pressure 4kg / cm^Two To transfer and fix the toner image on the first side
Perform (Step S07). Thus, one side of the recording material
A face image is formed. The recording material is a discharge roller 15 (see FIG.
1) (see step S10). FIG. 7 shows a second embodiment of the present invention.
The gloss of the image when the pressure during transfer and fixing is changed
It is a graph which shows a change. As shown in FIG.
The pressure is 2, 4, 6 kg / cm ^Two 3
Gross decrease rate dG / G
It is a thing that I did. How to measure the gross reduction rate dG / G
This is the same as in the first embodiment. As shown in FIG. 7, the pressure at the time of transfer and fixing is
The gross reduction rate dG / G decreases as the value increases. This
This is because the pressure on the recording material is increased by increasing the pressure during transfer and fixing.
Increasing the amount of deposition increases the degree of melting of the toner image
The gap between toner particles in the toner image on the first side of the recording material is reduced.
To form a dense fixed toner image.
Also makes it difficult to create irregularities on the surface
It is thought to be reduced. Next, a third embodiment of the present invention will be described.
I will tell. This embodiment corresponds to a third image forming apparatus of the present invention.
It is an embodiment about. FIG. 8 shows a third image of the present invention.
It is a schematic structure figure of one embodiment of a forming device. This implementation
The third embodiment uses a third image forming apparatus of the present invention using an intermediate transfer member.
Digital color printer with simultaneous transfer and fixing
Applied. This image forming apparatus 200 is used for both sides of a recording material.
Double-sided mode, which forms an image on one side, and
It has two operation modes, one-sided mode for performing image formation.
To analyze the input data from the outside and
A mode determination unit 20 that determines whether a command has been issued,
Image forming apparatus 10 based on the determination result of mode determination unit 20
0 indicates the operation mode of the duplex mode or the simplex mode.
Process control unit that controls whether to operate based on the mode
21 and the surface of the recording material when the duplex mode is specified.
And a recording material reversing device 30 for reversing the back.
You. The recording material reversing device 30 includes transport direction switches 31 and 3
2. Recording material reversing unit 33 and recording material transport roll 34
a, 34b, etc. Further, the image forming apparatus 200
When the operation mode is set to duplex mode,
The recording material on which the image has been formed is
Heat and pressure by the heating and pressing member
After recording, the surface roughness of the recording material
Is formed on the surface of the recording material by bringing the
Toner image smoothing device 40 for smoothing the surface of the
Provided. The structure of the image forming apparatus 200 is shown in FIG.
The configuration of the image forming apparatus 100 according to the first embodiment shown in FIG.
Although similar, both are processes of the image forming apparatus 100.
The toner amount control circuit 22 provided in the control unit 21
It is not provided in the image forming apparatus 200, and instead,
The fact that a toner image smoothing device 40 is provided is an advantage.
Wrong. The image forming apparatus 200 shown in FIG.
When the image data sent from
Reference numeral 20 denotes an image forming apparatus 1 from the PC 7 prior to image formation.
The control signal included in the image data input to 00 is
Analyzes can be performed in either duplex mode or simplex mode.
Determines whether the shift operation mode has been specified and the result
Is transmitted to the process control unit 21. Process control unit 21
Is an image forming apparatus based on the determination result of the mode determination unit 20.
The process of each part in the 200 is adjusted to the specified operation mode.
Control. The image forming apparatus 200 operates in a duplex mode.
2 when image data is input when forming an image by
Transfer and fixation on the back surface of the recording material 3 in the image formation of the surface
The process up to this point is the same as in the first embodiment.
It is like. Formed by transfer-fixing on the back surface of the recording material 3
The image on the second side is recorded as described with reference to FIG.
The first fixed toner image formed on the surface of the material is the second
The surface is uneven due to heating and pressing, and the gloss is reduced.
are doing. The toner image smoothing device 40 shown in FIG.
Transfer fixing with reduced glossiness due to uneven surface like
This is an apparatus for smoothing the surface of an image later. FIG.
Explanation of the operation of smoothing the image surface by the toner image smoothing device
FIG. As shown in FIG. 8 and FIG.
The smoothing device 40 is an endless belt-shaped toner having a smooth surface.
A smoothing member 41 and a support for supporting the toner smoothing member 41
Holding roller 42 and toner smoothing member 41 on the surface of recording material 3
The toner smoothing member 41 on the surface of the recording material 3
From the toner smoothing member moving device 43 which is kept away from
Become. As shown in FIG.
Corresponds to the image on the first side during the transfer and fixing of the second side
The recording paper 3 on which the toner image 2a has been formed on the front surface 3a is turned over.
So that the back surface 3b of the recording material 3 contacts the intermediate transfer member 1.
Then, the back surface of the recording material 3 primarily transferred onto the intermediate transfer body 1
3b, a toner image 2b corresponding to the image formed
And the heating and pressing low
At the heating and pressing position T2 formed by the nip of
Supplied. The recording paper 3 is supplied to the heating and pressing position T2
The timing corresponds to the image of the second surface on the intermediate transfer body 1
Timing when the toner image 2b reaches the heating and pressing position T2
Is consistent with As shown in FIG. 9B, the heating and pressing position T
The recording paper 3 supplied to 2 is heated and rolled by rolls 4 and 5
Heated and pressed, the second surface on the intermediate transfer member 1
The toner image 2b corresponding to the image of FIG.
And the first surface formed on the surface 3a of the recording paper 3
The toner image 2a corresponding to the image of FIG.
And pressurized. Surface of recording paper 3
The surface of the first toner image 2a on 3a is heated and pressed for the second time.
The surface becomes uneven due to the
The recording paper 3 that has passed the pressure position T2 is
In contact with the toner smoothing member 41 having surface roughness
As shown in FIG. 9C, the toner having a rough surface
-The unevenness on the surface of the image 2a is smoothed again and has a high glossiness
The surface is reformed. Record passed through the heating and pressing position T2
On the back surface 3b of the paper 3, a high-gloss transfer fixed toner image 2b is provided.
An image with high gloss on both sides because it is formed
Is obtained. FIG. 10 shows a third embodiment of the present invention.
Of glossiness of image by presence or absence of toner smoothing member
FIG. As shown in FIG.
Indicates that the toner is used when forming the second image in the duplex mode.
Formed on the surface 3a of the recording material 3 using the smoothing member 41
The case where only the first side image is smoothed and the case where the toner smoothing unit
The gross reduction rate dG / G when the material 41 is not used.
It is a lot. How to measure the gross reduction rate dG / G
The method is the same as in the first and second embodiments.
You. As shown in FIG. 10, the toner smoothing member 4
1 to smooth the image of the first surface already formed on the recording material surface
If the toner smoothing member 41 is not used,
The gloss reduction rate is reduced to about one third as compared with the case.
This is because of the surface of the toner image generated by the second transfer fixing.
Unevenness is smoothed by the toner smoothing member 41 and high gloss
This is because the surface was re-formed. In this embodiment, the IPS 8 and the
The driver units 9a, 9b, 9c, 9d, mirror
10a, 10b, 10c, 10d, and charged charge
The keys 11a, 11b, 11c and 11d are the electrostatic
This corresponds to a latent image forming unit, and is used in the present embodiment.
Developing rolls 12a, 12b, 12c, and 12d according to the present invention.
This corresponds to the toner image forming means described in
Transfer device 14a, 14b, 14 in the form
c and 14d correspond to the primary transfer means in the present invention.
The heating and pressing rolls 4 and 5 in the present embodiment are
Equivalent to the heating and pressing member of the transfer fixing means according to the invention
The support roll 17b in the present embodiment is the present invention.
This corresponds to the peeling means described in
Recording material transport roll 19 and recording material reversing device 30
This corresponds to the recording material conveying means according to the present invention.
The mode determination unit 20 in the embodiment determines according to the present invention.
The toner according to the present embodiment
The image smoothing device 40 is used as a toner image smoothing unit according to the present invention.
It is equivalent. Next, the fourth embodiment of the present invention will be described.
The form will be described. According to the fourth image forming apparatus of the present invention,
The configuration is the same as that of the image forming apparatus of the first embodiment shown in FIG.
Image forming apparatus similar in configuration but of the first embodiment
Mode judgment unit 20 and process control unit 2 provided in
1, and the toner amount control circuit 22 is not provided.
Instead, in the fourth image forming apparatus of the present invention,
Is a pair of heating and pressing rolls 4 and 5 which are heating and pressing members.
The heating / pressing roll 5 on the side in contact with the recording material 3
It is composed of a roll having a surface roughness equal to or less than the particle size. As described above, the surface of the heating and pressing roll 5 is
-By having a smooth surface with a surface roughness equal to or less than the particle size,
Irregularities on the image surface depending on the surface shape of the heating / pressing roll 5
Can be suppressed. Further, the fourth aspect of the present invention
Immediately after the heating and pressing rolls 4 and 5 of the image forming apparatus of FIG.
And the toner smoothing device 40 shown in FIG.
Image formation on the second side by the toner smoothing device 40.
Of the image on the first surface of the recording material 3 after heating and pressing at the time
By smoothing the image surface, one surface of the recording material surface
This can further increase the smoothness of the toner image surface of the eye image.
Can be. [0051] As described above, according to the first aspect of the present invention,
According to the image forming apparatus, the electrostatic latent image formed on the photoreceptor is
Providing toner amount control means for controlling the amount of toner to be attached
Therefore, according to the second image forming apparatus of the present invention,
Pressing force control to control the pressing force by the heating and pressing member
Means to form images on both sides of the recording material.
The image on the first side
Surface of the toner image to be smooth
In both cases, a high gloss image can be obtained. According to the third image forming apparatus of the present invention,
For example, the surface of the recording material heated and pressed by the heating and pressing member
Contacting a member having a surface roughness equal to or less than the
Smoothes the surface of the image formed on the recording material surface
By providing a toner image smoothing means, both sides of the recording material
The second time when it is instructed to form an image
Surface of the toner image corresponding to the image on the first surface by heating and pressing
Even if unevenness occurs on the surface, make the toner image surface smooth again
And a glossy image can be obtained on both sides. According to the fourth image forming apparatus of the present invention,
For example, the side of the pair of heating and pressing rolls
Roll the heating and pressing roll with a surface roughness smaller than the toner particle size.
The side in contact with the heating and pressing roll
Surface of the recording material can be made a smooth surface,
High gloss image can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a first embodiment of an image forming apparatus of the present invention. FIG. 2 is a flowchart of an image forming process according to the first embodiment of the present invention. 3A and 3B are a top view and a cross-sectional view of a toner image corresponding to an image formed on both sides by a conventional image forming apparatus, which is shown as a comparative example. 4A and 4B are a top view and a cross-sectional view of a toner image corresponding to an image formed in the duplex mode by the image forming apparatus according to the embodiment. FIG. 5 is a graph showing a change in glossiness of an image when an image is formed by changing an exposure light intensity according to the first embodiment of the present invention. FIG. 6 is a flowchart of an image forming process according to a second embodiment of the present invention. FIG. 7 is a graph illustrating a change in glossiness of an image when a pressing force during transfer and fixing is changed according to the second embodiment of the present invention. FIG. 8 is a schematic configuration diagram of an embodiment of a third image forming apparatus of the present invention. FIG. 9 is a diagram illustrating an operation of smoothing an image surface by a toner image smoothing device. FIG. 10 is a graph showing the effect on the glossiness of an image depending on the presence or absence of a toner smoothing member according to the third embodiment of the present invention. FIG. 11 is a graph showing a state in which the gloss of an image is reduced when a double-sided image is formed by a conventional image forming apparatus employing the simultaneous transfer and fixing method. FIG. 12 is a cross-sectional view of a toner image at the time of forming an image on the first side in a case where double-sided image formation is performed by a conventional image forming apparatus employing a simultaneous transfer and fixing method. FIG. 13 is a schematic diagram showing a state of a toner image when forming an image on the second surface when a double-sided image is formed by a conventional image forming apparatus employing a simultaneous transfer and fixing method. [Description of Signs] 1 Intermediate transfer body 2 Toner image 2a, 2b Fixed toner image 3 Recording material 3a Front surface 3b Back surface 4, 5 Heat / press rolls 6a, 6b, 6c, 6d Photoconductor drum 8 IPS 9a, 9b, 9c, 9d Laser driver units 10a, 10b, 10c, 10d Mirrors 11a, 11b, 11c, 11d Charging chargers 12a, 12b, 12c, 12d Developing rolls 13a, 13b, 13c, 13d Cleaners 14a, 14b, 14c, 14d Corotron transfer unit 15 Discharge Roller 16 Belt cleaners 17a, 17b, 17c, 17d Support roll 18 Paper tray 19 Recording material transport roll 20 Mode determination unit 21 Process control unit 22 Toner amount control circuit 30 Recording material reversing device 31, 32 Transport direction switching unit 33 Recording material reversal Units 34a, 34b Recording Material Conveyance Roll 40 Toner image smoothing device 41 toner smoothing member 42 supporting roller 43 toner smoothing member moving devices 100 and 200 an image forming apparatus

Continuation of the front page (72) Inventor Tetsuo Yamada 430 Nakai-cho, Ashigara-gun, Kanagawa Prefecture Green Tech Nakai Fuji Xerox Co., Ltd. (56) References JP-A-5-19642 (JP, A) JP-A-5-249795 (JP) JP-A-6-289686 (JP, A) JP-A-6-308839 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/16

Claims (1)

(57) [Claim 1] A toner image is formed.
After being transferred onto the intermediate transfer body, it is conveyed by the recording material conveying means.
On the recording medium superimposed on the intermediate transfer member.
The toner image is transferred and fixed by heat and pressure to form a toner image.
After cooling, the recording material is separated from the intermediate transfer member.
From the toner image fixed on the recording material.
In the image forming apparatus, the recording material conveying unit forms an image on both sides of the recording material.
Image is formed only on the surface when
The recording material contacted with the intermediate transfer body on the back side of the recording material.
The recording material transferred onto the intermediate transfer member
The toner image corresponding to the image formed on the back side of
The intermediate transfer member, and further has a surface roughness equal to or less than toner particles.
It has a belt-like member that can be freely attached to and detached from the transfer body.
To the surface when it is instructed to form an image
Is completed, and the back surface contacts the intermediate transfer member.
After heating and pressurizing
By bringing the member into contact with the recording material surface, the recording material
Image smoothing to smooth the surface of the image formed on the surface
An image forming apparatus characterized by including the means.