JPH05341660A - Image forming method and device therefor - Google Patents

Abstract

PURPOSE:To obtain an image forming method and device for imparting high transferability, even to a recording paper whose surface is rough. CONSTITUTION:Until before the leading edge of an image reaches a simultaneous transferring and fixing position, the recording paper 121 is fed from a paper feeding cassette not shown by the figure, moved in the direction of the arrow (c), and passes a preliminary processing means 122 executing either of heating and pressurizing or both of them, on the recording paper. Then, the recording paper 121 is moved in the direction of the arrow (d), so as to align the leading edge of the image on an intermediate transfer body 110, with the leading edge of the recording paper 121, and inserted into a simultaneous transferring and fixing means 130, and a toner image is simultaneously, transferred and fixed on the recording paper 121.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and apparatus. More specifically, the present invention relates to an image forming method and apparatus for transferring toner on an image bearing member to an intermediate transfer member and transferring and fixing the toner on the intermediate transfer member onto a recording sheet.

[0002]

2. Description of the Related Art A conventional image forming method or apparatus for transferring toner on an image bearing member to an intermediate transfer member and transferring and fixing the toner on the intermediate transfer member onto recording paper is disclosed in Japanese Patent Laid-Open No. Sho 49-49.
There was a publication of -78559.

In a transfer simultaneous fixing section of an image forming method or apparatus in which the toner on the image carrier is transferred to the intermediate transfer member and the toner on the intermediate transfer member is transferred and fixed on the recording paper at the same time.
It is desired to transfer and fix all the toner on the intermediate transfer member onto the recording paper. Therefore, it is necessary to make the adhesive force between the toner and the intermediate transfer member smaller than the internal cohesive force of the toner and the adhesive force between the toner and the recording paper.

To reduce the adhesive force between the toner and the intermediate transfer member,
That is, an intermediate transfer member having improved toner releasability is disclosed in JP-A-2-162379. JP-A-2
The intermediate transfer member disclosed in Japanese Patent Laid-Open No. 162379/1989 has excellent toner releasability, and can be collectively transferred onto a recording paper without leaving the toner on the intermediate transfer member on a relatively smooth recording paper. It was possible.

[0005]

However, many recording papers have irregularities on the surface thereof, and particularly in the case of rough recording papers having a Beck smoothness of about 4 to 10 seconds such as bond paper, toner and recording paper are used. There are few contact points with. Therefore, it is difficult to obtain a sufficient adhesive force between the toner and the recording paper for batch transfer, and batch complete transfer cannot be achieved only by improving the releasability of the intermediate transfer member. For this reason, a large amount of toner remains on the intermediate transfer member, and the residual toner on the intermediate transfer member is scraped and removed every time, so that there is a problem that the intermediate transfer member is worn and the life is short.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an image forming method and apparatus which give high transferability even to recording paper having a rough surface. Another object of the present invention is to provide an image forming method and apparatus in which residual toner on the intermediate transfer member after transfer and fixing is reduced and the life of the intermediate transfer member is significantly improved.

[0007]

SUMMARY OF THE INVENTION The present invention is an image forming method in which toner on an image carrier is transferred to an intermediate transfer member, and the toner on the intermediate transfer member is transferred and fixed on the recording paper at the same time. After applying either or both of the pressure and the pressure, the toner on the intermediate transfer member is simultaneously transferred and fixed onto the recording paper.

The present invention provides an image forming apparatus having means for transferring the toner on the image carrier to the intermediate transfer body and means for simultaneously transferring and fixing the toner on the intermediate transfer body onto the recording paper.
It is characterized by having a pretreatment means for applying one or both of heating and pressure to the recording paper.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic view of an image forming apparatus according to the present invention.

An image carrier 101 having a photosensitive layer having a sensitivity of at least 700 to 800 nm formed on an aluminum substrate receives an image formation start signal and starts to rotate in the direction of arrow a by a conveying means (not shown). Charger 10
2, the surface of the image carrier 101 is uniformly charged.
A laser beam 103 emitted from a laser light source (not shown) starts latent image formation corresponding to an image, and a developing device 104 develops toner on the image carrier 101.

Toner is transferred from the image carrier 101 by the transfer unit 111 onto the intermediate transfer member 110 which rotates in the direction of the arrow b at the same peripheral speed as the image carrier 101 by a transporting unit (not shown).

By the time the leading edge of the image (not necessarily the leading edge of the toner image on the intermediate transfer member 110) reaches the simultaneous transfer fixing position, the recording paper 121 is fed from a paper feeding cassette (not shown), and the arrow mark Pretreatment means 12 which moves in the c direction and applies one or both of heating and pressure to the recording paper.
Pass 2. Then, the recording paper 1 is adjusted so that the leading edge of the image on the intermediate transfer member 110 and the leading edge of the recording paper 121 are aligned.
21 moves in the direction of arrow d and is inserted into the simultaneous transfer fixing unit 130.

After the image is transferred and fixed on the recording paper 121 at the same time, the recording paper 121 is peeled from the intermediate transfer member 110 by a peeling means (not shown).

After the toner is transferred to the intermediate transfer member 110, the image carrier 101 is operated by the discharging light 105 emitted from a light source (not shown) and the cleaning means 106, and the image carrier 1 is operated.
The toner and electric charge remaining on 01 are removed. Further, if necessary, after the toner is transferred and fixed onto the recording paper 121 at the same time, the intermediate transfer body 110 is subjected to removal of the toner and electric charge remaining on the intermediate transfer body 110 by a cleaning unit and a discharging unit not shown.

Through the above steps, a toner image is obtained on the recording paper.

As a result of extensive studies by the present inventor, in order to improve the adhesive force between the toner and the recording paper and to improve the transferability (simultaneous transfer fixing property) of the toner to the recording paper having a rough surface. It was found that it is effective to modify the surface of the recording paper. Surface modification includes heating the recording paper to remove moisture adhering to and adhering to the surface of the recording paper, making it easier to wet the toner and the recording paper (improving adhesive strength), pressurizing the recording paper, There are two methods of smoothing the surface of the recording paper (increasing the adhesion area), and the effect is exhibited by applying at least one of them. The pretreatment means 122 is used for modifying the surface of the recording paper 121.

FIG. 1 shows an example in which the above-mentioned surface modification is simultaneously performed as the pretreatment means 122, and the constitution thereof comprises a first heating roller 123 and a first pressure roller 124. The first heating roller 123 is maintained at a predetermined temperature, and both rollers are pressed with a predetermined load. It is desirable to dispose the first heating roller 123 on the side of the recording paper 121 on which the toner image is transferred and fixed.

Here, the first heating roller is a cylindrical roller made of a metal or alloy such as aluminum, nickel or stainless, a heat resistant resin such as polyimide or polyaramid, or a ceramic, and a first lamp 125 inside the roller. Is a built-in configuration. A heat resistant rubber layer such as silicone rubber or fluororubber may be formed on the surface of the first heating roller 123. The first pressure roller 124 is
It is composed of a metal roller, a roller around which a metal core is coated with heat resistant rubber, and the like.

Although not shown, the pretreatment means 12
2, a temperature detector is attached, and power supply to the first lamp 125 is controlled so that the surface temperature of the first heating roller 123 becomes substantially constant.

The transfer / fixing means 130 comprises a second heating roller 131 and a second pressure roller 132.
The second heating roller 131 is maintained at a predetermined temperature, and both rollers are pressed with a predetermined load. Intermediate transfer member 110
It is preferable that the second heating roller 131 is arranged on the back side of the. A second lamp 133 is arranged inside the second heating roller 131, and a second lamp 133 is arranged so that the surface temperature of the second heating roller 131 becomes substantially constant according to the temperature detected by a temperature detector (not shown). The power supply to the second lamp 133 is controlled. The pressing force of the second heating roller 131 and the second pressure roller 132 is a linear pressure of 10 g.
/ Cm to 10 kg / cm, preferably 50 g / cm to
It is 300 g / cm. Due to the heat of the second heating roller 131, the toner has a glass transition temperature or higher, preferably,
When heated above the softening temperature, it becomes rubber or softens,
The recording paper 121 gets wet and penetrates into the recording paper 121 by a pressing force, so that the toner and the recording paper 121 have an adhesive force. As described above, since the surface modification of the recording paper 121 is performed by the pretreatment means 122, the toner on the intermediate transfer member 110 is recorded on the recording paper 1.
21 is completely transferred and fixed.

The second heating roller 131 is a cylindrical roller made of a metal or alloy such as aluminum, nickel or stainless, a heat resistant resin such as polyimide or polyaramid, or a ceramic. A heat resistant rubber layer such as silicone rubber or fluororubber may be formed on the surface of the second heating roller 131. The second pressure roller 132 is composed of a metal roller, a roller having a metal cored bar covered with heat resistant rubber, and the like.

The photosensitive layer of the image carrier 101 may be an organic photoconductor, an inorganic photoconductor, a composite photoconductor of organic and inorganic materials, and is a means for forming a latent image (here, the laser beam 10 is used).
3 is used, it is sufficient to have sensitivity in the wavelength range of the light generated by (3). Further, the image carrier 101 does not have to have a cylindrical shape, and the photosensitive layer may be formed on the film substrate. As the charger 102, for example, a corotron, a scorotron, a roller type, or a brush type can be used, and the charging polarity of the image carrier 101 may be selected according to the characteristics of the photosensitive layer used. Developing means 10
As for 4, a known means, for example, a two-component magnetic brush developing means, a one-component magnetic brush developing means, a one-component jumping developing means, a one-component pressure contact developing means, etc. can be applied.

The toner is particles having a particle size of 5 to 20 μm in which a coloring material is dispersed in a binder resin such as polyester resin or styrene acrylic resin, and if necessary, metal soap, polyethylene glycol or the like is used. Surfactants (dispersants), electron-accepting organic complexes, chlorinated polyesters, nitrofunnic acid, quaternary ammonium salts, charge control agents such as pyridinium salts, mold release agents such as polypropylene wax, fillers such as talc, A fluidity improver such as SiO ₂ or TiO ₂ is added internally or externally. Each toner is uniformly mixed and dispersed in each developing device, and is charged with a predetermined electric charge. You may mix with a carrier in a developing device. The charge polarity of the toner becomes negative when the image carrier 101 is charged negatively and reversal development is performed.

The intermediate transfer member 110 may have a structure such as a cylindrical roller, a cylindrical roller having a peripheral surface cut out to form a film, or a film. Examples of rollers include metals such as aluminum, alloys, and ceramics. Examples of the film include metals such as nickel, alloys,
There are resins such as ceramics, polyimide and polyaramid, and those obtained by mixing carbon black, metal, ceramics and the like with the above resins. Since the intermediate transfer member 110 is heated by the simultaneous transfer fixing unit 130, the glass transition temperature is 2 or less.
It is preferably composed of a substance having a glass transition temperature of 00 ° C. or higher, or no glass transition. Further, as described above, it is desirable that the surface is coated with a silicone resin or a fluororesin, which is excellent in toner releasability.

The transfer means 111 may be a scorotron, a corotron, a roller type, a brush type transfer device or the like. Both are arranged on the back side of the intermediate transfer body 110 (the side where the image carrier 101 is not present).

The static elimination light 105 may be light in a wavelength range in which the photosensitive layer of the image carrier 101 has sensitivity, and is, for example, an LED lamp. An example of the cleaning unit 106 is a blade type cleaning device. If the toner and charges remaining on the image bearing member 101 can be removed, the neutralization light 10
5. The arrangement of the cleaning means 106 is arbitrary. Further, the charge removal light 105 may be applied to the image carrier 101 a plurality of times. For example, with respect to the cleaning means 106, a static elimination light generator is provided on both the upstream side and the downstream side, or
The static elimination light path may be arranged and the static elimination light 105 may be irradiated.

With this structure, the toner on the intermediate transfer member 110 can be completely transferred and fixed on the recording paper 121.

As the pretreatment means 122, the above surface modification may not be performed at the same time. For example,
It is conceivable that the recording paper 121 is heated using a heat source such as a flash and then passed through the pressure roller, or is passed through the pressure roller and then heated using a heat source. At this time, the pressure roller is pressed with a predetermined load, and it is desirable that the heat source is arranged on the side of the recording paper 121 on which the toner images are transferred and fixed.

The intermediate transfer body 110 to the recording paper 121
Since the complete transfer and fixing to the intermediate transfer member 110 is possible, the residual toner on the intermediate transfer member 110 is almost eliminated, and cleaning is not required every time, and the cleaning unit may be operated once every several times. Therefore, the life of the intermediate transfer member could be significantly improved.

The present invention is not limited to this embodiment.

To give an example, the present invention is not limited to monochromatic image formation, but is limited to monocolor, multicolor,
Widely applicable to full-color image formation.

For example, in the case of forming a full-color image, the toner formed on the image carrier is electrostatically transferred to the intermediate transfer body one by one, the toner images are superposed on the intermediate transfer body, and they are collectively transferred and fixed on the recording paper. As a result, a color image can be obtained on the recording paper. In this case, the peripheral length of the intermediate transfer member needs to be equal to or longer than the length of the maximum recording paper used.

As the image bearing member, a conductive substrate having a dielectric layer formed thereon may be used to form a latent image with an ion flow charger.

In the following Examples 2 to 4, the surface of the recording paper 121 is modified, and the recording paper is heated to remove the water adhering to and adsorbed on the surface of the recording paper to facilitate the wetting of the toner and the recording paper ( To improve the adhesive strength) and pressurize the recording paper to smooth the surface of the recording paper (increase the adhesive area), are effective for completely transferring and fixing the toner on the intermediate transfer member 110 to the recording paper 121. I did a confirmation experiment. Specifically, an experiment was conducted to confirm the effects of surface modification both in Example 2, in Example 3, and in Example 4.

Example 2 Confirmation Experiment of Surface Modification Effect The apparatus configuration used in the experiment is the same as that shown in FIG. 1, and the first pressure roller 124 and the first heating roller of the pretreatment means 122 are used. The experiment was conducted by releasing the pressure applied to 123 and changing the surface temperature of the first heating roller 123 to each value shown in Table 1. The first heating roller 123 is an aluminum tube having a diameter of 20 mmφ and a wall thickness of 2 mm.
A halogen lamp was used as the lamp 125. The pressure applied to the second heating roller 131 and the second pressure roller 132 of the simultaneous transfer fixing unit 130 is a linear pressure of 200 g /
cm, and the surface temperature of the second heating roller 131 is 15
It was set to 0 ° C. The process speed (recording paper conveyance speed) is 3 cm / sec, and the toner used has a glass transition temperature of 70.
As the recording paper 121, Ninabond paper having a Beck smoothness of 4 seconds, that is, a rough surface was used as the recording paper 121, and 1 × 1 dots were arranged on a grid point at intervals of 2 dots as an image. As the intermediate transfer member 110, one obtained by laminating PTFE in a thickness of 20 μm on a seamless belt having a conductivity of 50 μm and having a thickness of 50 μm was used.

Table 1 also shows the image evaluation results on Ninabond paper after transfer and fixing. The heating temperature in Table 1 is the first
Is the surface temperature of the heating roller 123. Here, the heating temperature: room temperature means that the surface temperature of the first heating roller 123 is made the same as room temperature without supplying the electric power to the first lamp 125 of the first heating roller 123. .. As the image evaluation, a judgment criterion was a rate at which some dots were missing, some dots were missing, etc. in the 1 × 1 dot array image on the recording paper. The symbols in the table are respectively: ◯: perfect transfer simultaneous fixing without dot missing and omission was possible, Δ: almost complete transfer simultaneous fixing with dot omission and omission ratio within 10%, x: It indicates that there was a dot dropout and dropout ratio of 10% or more, complete transfer simultaneous fixing was not carried out, and most of the images had dropouts.

[0038]

[Table 1]

From the results, it can be seen that the heating temperature: room temperature, that is, complete transfer simultaneous fixing cannot be achieved by the conventional technique, but complete heating simultaneous fixing can be achieved by heating within a predetermined optimum range. This is the effect of surface modification of the recording paper 121.

The optimum heating temperature range was 60 ° C. or higher, and preferably 80 ° C. or higher. From this,
It can be seen that when heating the surface of the recording paper for heating, it is sufficient to remove the water present on the surface of the recording paper, and it is not necessary to remove the water on the entire recording paper. However, if the heating temperature exceeds approximately 250 ° C., the members constituting the heating roller deteriorate rapidly and the recording paper deteriorates.

Since the degree of the pretreatment applied to the recording paper differs depending on the conveying speed of the recording paper, the above-mentioned optimum range is not always applicable to all cases. For example, when the recording paper conveyance speed is 1 cm / sec, the heating temperature is 60 ° C.
It was possible to obtain a complete transfer simultaneous fixed image without any dot dropouts or omissions even if only the above was added.

From the above results, the surface of the recording paper 121 is modified, the recording paper is heated to remove the water adhering to and adsorbed on the surface of the recording paper, and the toner and the recording paper are easily wetted (the adhesive strength is improved. Is effective for completely transferring and fixing the toner on the intermediate transfer member 110 to the recording paper 121.

Experiment for Confirming Surface Modification Effect of (Example 3) First heating roller 1 of pretreatment means 122 shown in FIG.
The experiment was performed by changing the pressing force of the first pressure roller 124 and the first heating roller 123 to each value shown in Table 2 without supplying electric power to the first lamp 125 of No. 23. .. Here, the first pressure roller 124 has a diameter of 10 mm.
A φ stainless steel shaft having a 5 mm thick HTV silicone rubber layer was used. The other experimental conditions were the same as in Example 2.

Table 2 also shows the image evaluation results on Ninabond paper after transfer and fixing. Image evaluation was performed in the same manner as in Example 2. The pressure of 0 g / cm in Table 2 means that the pressure applied to the first pressure roller 124 and the first heating roller 123 has been released.

[0045]

[Table 2]

From the results, the applied pressure: 0 g / cm, that is,
It is understood that the conventional technique cannot achieve complete simultaneous transfer and fixing, but it is possible to achieve simultaneous complete transfer and fixing when pressure is applied within a predetermined optimum range. This is the effect of surface modification of the recording paper 121.

Here, the optimum range of the pressing force is a linear pressure of 50.
It was at least g / cm, preferably at least 200 g / cm. However, although not shown in Table 2, the linear pressure is approximately 5k.
If it is at least g / cm, the recording paper will be completely smoothed, so the linear pressure is preferably at most 5 kg / cm.

As another experiment, a diameter of 20 mmφ and a wall thickness of 2
When an experiment was carried out using a 1 mm aluminum tube as the first pressure roller 124, the applied pressure (linear pressure) was 200 g / c.
At the time of m or more, complete transfer simultaneous fixing could be achieved.

From the above results, the surface of the recording paper 121 is modified, and the recording paper is pressed to smooth the surface of the recording paper (increase the adhesive area), but the toner on the intermediate transfer member 110 is removed. It has been proved to be effective in completely transferring and fixing to.

(Embodiment 4) Experiment for Confirming Effect of Simultaneous Surface Modification with First Embodiment In the pretreatment means 122 shown in FIG. 1, the surface temperature of the first heating roller 123 and the first pressure roller 1
An experiment was performed by changing the pressure applied to the first heating roller 123 and the first heating roller 123 as shown in Table 3. The structure of the first heating roller 123 was the same as that of Example 2, the structure of the first pressure roller 124 was that of Example 3, and the other experimental conditions were the same as those of Example 2.

Table 3 also shows the image evaluation results on Ninabond paper after transfer and fixing. Image evaluation was in accordance with Example 2.

[0052]

[Table 3]

As is clear from a comparison of Tables 1 to 3, it can be seen that the simultaneous application of both pressurization and heating can further reduce the optimum range in the case of performing each independently due to the interaction between the two.

Although not shown in the figure as another experiment, an experiment in which neither pressurization nor heating was performed at the same time was also performed.
Specifically, the pressure is applied and then the heating is performed, or the heating and then the pressure is applied. Here, the pressurization was performed by passing the paper through a pair of rollers in contact with each other at a pressing force (linear pressure) of 100 g / cm. One pair of rollers has a diameter of 2
It consists of an aluminum tube with a diameter of 0 mm and a thickness of 2 mm.
m HTV silicone rubber layer was used. Heating uses the heat of the flash lamp,
The surface of the recording paper 121 on which the toner was transferred and fixed was measured. The light intensity of the flash lamp was controlled so that the surface temperature (heating temperature) of the recording paper 121 was 60 ° C.

Under the above conditions, the Ninabond paper as the recording paper 121 was subjected to the pretreatments of pressurizing and then heating, and heating and then pressurizing, respectively. From this, it was found that even if both pressurization and heating are performed simultaneously (separately with a time lag), the optimum range can be further reduced in the case of performing each independently due to the interaction between the two.

From the above results, the surface of the recording paper 121 is modified, the recording paper is heated to remove the water adhering to and adsorbed on the surface of the recording paper, and the toner and the recording paper are easily wetted (the adhesive strength is improved. It is effective for completely transferring and fixing the toner on the intermediate transfer member 110 to the recording paper 121 by pressing the recording paper and smoothing the surface of the recording paper (increasing the adhesion area). Proved.

(Embodiment 5) FIG. 2 is a schematic view of another image forming apparatus according to the present invention.

In the figure, the same components as in the first embodiment are
The same reference numerals are given, and the description and drawings of the same contents are omitted.

The intermediate transfer member 110 stands by at a standby position (not shown) which is not in contact with the image carrier 101, and when an image formation start signal is received, it is moved in a direction opposite to the arrow b by a conveying means (not shown). Start spinning. The recording paper 121 is moved in the direction of arrow c from the position A, and the transfer simultaneous fixing unit 1
After passing through 40, either one or both of heating and pressurization is performed, and it moves in the direction of arrow x and stands by at a position of approximately B.

Here, the simultaneous transfer and fixing means 140 also serves as a preliminary processing means.

In FIG. 2, the constitution of the transfer fixing means 140 comprises a heating roller 141 and a pressure roller 142. The heating roller 141 has a built-in lamp 143,
It is kept at a predetermined temperature and both rollers are pressurized with a predetermined load. It is desirable to dispose the heating roller 141 on the side of the recording paper 121 on which the toner image is transferred and fixed.

Then, the intermediate transfer member 110 comes into contact with the image carrier 101 by a moving or rotating means (not shown), and the image carrier 101 and the intermediate transfer member 110 are respectively indicated by arrows a,
Start rotation in the b direction. The toner image formed on the image carrier 101 is transferred from the image carrier 101 to the intermediate transfer member 110. Simultaneous transfer fixing means 1 moves the recording paper 121 from the standby position of B in the direction of arrow y so that the leading edge of the image on the intermediate transfer member 110 and the leading edge of the recording paper 121 are aligned.
It is inserted in 40. Then, the image is transferred and fixed onto the recording paper 121 at the same time, the path is switched by a transport path switching means (not shown), the recording paper 121 is moved in the direction of arrow d, and is discharged to the position C to obtain a predetermined image. ..

The heating roller 141 is a cylindrical roller made of a metal or alloy such as aluminum, nickel or stainless, a heat resistant resin such as polyimide or polyaramid, or a ceramic. A heat resistant rubber layer such as silicone rubber or fluororubber may be formed on the surface of the heating roller 141. The pressure roller 142 is composed of a metal roller, a roller having a metal cored bar covered with heat resistant rubber, and the like.

The conditions of the simultaneous transfer and fixing means 140 do not necessarily have to be the same in the pretreatment and the simultaneous transfer and fixing. For example, at the time of preliminary processing, the pressure applied to the heating roller 141 and the pressure roller 142 is released, the surface of the recording paper 121 is modified (preliminary processing) only by heating, and at the time of simultaneous transfer and fixing, the heating roller 141 and the pressure roller 142 are pressed. The roller 142 and the roller 142 may be pressed to perform simultaneous transfer and fixing. The pretreatment condition and the simultaneous transfer fixing condition are as described in Examples 1 and 2.

By adopting such a configuration, the surface of the recording paper 121 was modified, and the toner on the intermediate transfer member 110 could be completely transferred and fixed onto the recording paper 121.

The conveyance path of the recording paper 121 and the image forming process are not limited to the above.

For example, the intermediate transfer member 110 may be replaced with the image carrier 10.
Even when the image forming apparatus 1 is not made to stand by at the non-contact waiting position with respect to 1, the image formation can be performed as follows. The image carrier 101 is also made rotatable in the direction of arrow a and the opposite direction, and when the intermediate transfer member 110 starts rotating in the direction opposite to the arrow b in response to the image formation start signal, the image carrier is rotated at the same rotation speed. 1
01 is rotated in the direction opposite to the arrow a. And
The recording paper 121 is passed from the position A to the simultaneous transfer and fixing means 130 to perform a preliminary process, and after moving to the standby position B, the rotation directions of the image carrier 101 and the intermediate transfer member 110 are changed.
Switching to the directions of arrows a and b, respectively, is a series of steps to form the upper toner image on the image carrier 101, the intermediate transfer member 110.
The transfer may be performed upward, the recording sheet may be conveyed from the standby position of B, and the transfer and fixing may be performed on the recording sheet 121 at the same time.

Further, it is not necessary to pass the recording paper 121 to the simultaneous transfer and fixing means 140 only once for the preliminary processing, and the recording paper 121 may be passed to the simultaneous transfer and fixing means 140 a number of times. For example, the recording paper 121 is made to stand by at the position B, the image forming signal is received, and the transfer simultaneous fixing unit 14 is provided.
It is also possible to prepare for image formation by moving 0 to the position A in the arrow y direction and again moving the simultaneous transfer and fixing unit 140 to the position B in the arrow c direction. In this case, the preliminary processing on the recording paper is performed by the simultaneous transfer and fixing unit 140 of the recording paper 121.
It is sufficient to perform either one or both of the first and second passages (forward and backward).

Further, it is not necessary to carry out a series of steps after preliminarily treating the recording paper 121 each time.
The image formation may be performed after waiting 21 at the position B.

Further, it is not necessary to pass the recording paper 121 through the transfer / fixing means 140 twice (preliminary processing and transfer / fixing simultaneously). For example, in FIG. 2, the recording paper 121 is conveyed from the position B along the pressure roller 142, and then inserted into the simultaneous transfer fixing unit 140 to simultaneously transfer the toner image on the intermediate transfer member 110 to the recording paper 121. May be fixed. In this case, since the pressure roller 142 rotates in contact with the heating roller 141, the pressure roller 142 absorbs the heat of the heating roller 141 and the surface thereof reaches a predetermined temperature. Therefore, the recording paper 121 is applied to the pressure roller 1
By feeding along 42, heating as a pretreatment is performed. However, since the surface of the recording paper 121 opposite to the surface on which the toner images are transferred and fixed simultaneously is heated, in order to remove the moisture on the surface of the recording paper 121 on the side where the toner images are transferred and fixed simultaneously. Is the pressure roller 14
2 to increase the contact time between the recording paper 121 and the surface temperature of the pressure roller 142,
It is desirable that the pressure roller 142 that raises the surface temperature of the heating roller 141 is made of a material having a high heat retention property.

[0071]

As described above, according to the present invention, the toner on the image carrier is transferred to the intermediate transfer member, and the toner on the intermediate transfer member is transferred and fixed on the recording paper at the same time. After heating or pressing the paper, or both, the toner on the intermediate transfer body is transferred and fixed to the recording paper at the same time. It has become possible to provide a forming method. Furthermore, there is no residual toner on the intermediate transfer member,
Since the number of cleanings can be reduced, it is possible to provide an image forming method in which the life of the intermediate transfer member is significantly improved.

Further, the present invention is an image forming apparatus having means for transferring the toner on the image carrier to the intermediate transfer body and means for simultaneously transferring and fixing the toner on the intermediate transfer body onto the recording paper. Since it has a pretreatment means for performing either or both of heating and pressing, it is possible to provide an image forming apparatus capable of complete transfer and simultaneous fixing even on recording paper having a rough surface. Furthermore, since the residual toner on the intermediate transfer body is eliminated and the number of cleanings can be reduced, it is possible to provide an image forming apparatus in which the life of the intermediate transfer body is significantly improved.

Further, since the image forming method and apparatus of the present invention can perform the steps of transferring and fixing the toner onto the recording paper at the same time, the apparatus can be simplified and downsized. Since the amount of toner remaining on the medium is very small, the number of times the cleaning device is driven and the volume of the waste toner container of the cleaning device can be reduced.

The image forming method and apparatus of the present invention is not limited to monochrome, and is particularly effective when applied to an image forming apparatus such as a printer, a video printer, a facsimile, a copying machine and a display.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an image forming apparatus according to the present invention.

FIG. 2 is a schematic view of another image forming apparatus according to the present invention.

[Explanation of symbols]

 101 image carrier 110 intermediate transfer member 111 transfer means 121 recording paper 122 pretreatment means 123 first heating roller 124 first pressure roller 125 first lamps 130, 140 simultaneous transfer fixing means 131 second heating roller 132 Second pressure roller 133 Second lamp 141 Heating roller 142 Pressure roller 143 Lamp

Claims (3)

[Claims] 1. An image forming method of transferring toner on an image carrier to an intermediate transfer member and transferring and fixing the toner on the intermediate transfer member onto recording paper at the same time, wherein either heating or pressure is applied to the recording paper, Alternatively, the image forming method is characterized in that the toner on the intermediate transfer member is transferred and fixed simultaneously on the recording paper after both are applied. 2. An image forming apparatus having means for transferring the toner on the image carrier to the intermediate transfer body and means for simultaneously transferring and fixing the toner on the intermediate transfer body to the recording paper. An image forming apparatus having a pretreatment unit for performing either one or both of the above. 3. The image forming apparatus according to claim 2, wherein the means for simultaneously fixing the transfer and the toner also serves as a preliminary processing means.