JP2003084590A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of securing productivity and avoiding the occurrence of blister at the time of fixing. SOLUTION: This image forming apparatus 10 is equipped with a primary fixing part 20 and a secondary fixing part 62. Therefore, by carrying special film to which a toner image is transferred to the primary fixing part 20, the toner image is fixed at the lowest fixing temperature at which the toner image is not be faultily fixed at specified carrying speed. Since the toner image is fixed at the low temperature in such a way, gas in a tone layer is gradually discharged to the outside and the blister is prevented from occurring. The special film primarily fixed in such a way is carried to the secondary fixing device 62, and the toner image is fixed at the fixing temperature at which it is excellently fixed. Since the gas has been mostly discharged, the toner image is excellently fixed without causing the blister. Namely, the blister is prevented and the image is excellently fixed without decreasing the fixing processing speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, as disclosed in Japanese Patent Laid-Open No. 8-262903, in order to quickly fix a toner image on a recording sheet and improve productivity,
A fixing device using a heating roll, a pressure pad, and a fixing belt (hereinafter referred to as a fixing device of a conventional example) has been proposed.

On the other hand, it has been attempted to make meter panels for automobiles and motorcycles by using an image forming apparatus. Specifically, a toner image is fixed on a special film for a panel by an image forming apparatus to form a light transmitting portion and a light non-transmitting portion. In this case, it is necessary to form a large amount of toner on the special film on the light non-transmissive portion.

[0004]

As described above, a large amount of toner is formed in the light non-transmissive portion in order to secure the concealing property. In addition, the special film that is the base material of the meter panel has a very high air permeability, and the gas contained in the toner layer formed on the special film is released only from the toner surface side (atmosphere side) during fixing. To be done.

Therefore, when fixing is carried out by a fixing device which processes quickly as in the conventional example, water in the special film or water in the toner layer is vaporized at the time of fixing and a blister which destroys the toner layer occurs. I will end up. As a result, there is a disadvantage that a pinhole is formed in the light non-transmissive portion and the hiding property is impaired.

On the other hand, in order to avoid the blister, a method of lowering the fixing temperature or the fixing speed can be considered.
However, lowering the fixing temperature may cause poor fixing, and lowering the fixing speed may lower productivity.

Therefore, an object of the present invention is to provide an image forming apparatus which ensures productivity and avoids blisters.

[0008]

The invention according to claim 1 is
In an image forming apparatus that forms an image on a recording medium by an electrophotographic method, a toner image forming unit that forms a toner image, a transfer unit that transfers the toner image onto the recording medium, and the transferred toner image are recorded by the recording unit. A plurality of fixing means for fixing to the medium, and the fixing temperature or the fixing pressure is increased for the fixing means located on the downstream side in the transport direction of the recording medium among the plurality of fixing means.

The operation of the invention according to claim 1 will be described.

The toner image formed by the toner image forming means is transferred onto the recording medium by the transfer means. The toner image is fixed on the recording medium to which the toner image is transferred by a plurality of fixing means. At this time, the plurality of fixing means are set so as to increase the fixing temperature or the fixing pressure toward the fixing means on the downstream side in the conveying direction, so that the blister is avoided while conveying at a conveying speed that does not impair the production efficiency. Then, the toner image is fixed.

Specifically, among the plurality of fixing means, the fixing means on the upstream side in the conveying direction is the minimum fixing that does not cause fixing failure of the toner image formed on the recording medium at a conveying speed that does not impair the production efficiency. Blisters are suppressed by setting the temperature or fixing pressure.

On the other hand, in the fixing means located on the most downstream side in the conveying direction, the fixing temperature or fixing pressure is set so that the toner image is favorably fixed on the recording medium at a predetermined conveying speed. Here, since most of the water and the like in the special film have already been vaporized because the fixing is performed by the fixing means on the upstream side in the transport direction. Therefore, blisters do not occur even when the fixing is performed at a predetermined fixing temperature or fixing pressure.

As described above, the plurality of fixing means are provided, and the fixing temperature or the fixing pressure is gradually increased toward the downstream side in the conveying direction, so that the image can be processed at a conveying speed that does not lower the image forming processing efficiency during the fixing. The toner image can be fixed without causing blister.

This is particularly effective when a thick toner layer is formed on the recording medium to form the light opaque portion or when the recording medium has a high air permeability.

According to a second aspect of the invention, in an image forming apparatus for forming an image on a recording medium by an electrophotographic method, a toner image forming means for forming a toner image and a transfer means for transferring the toner image on the recording medium. And a plurality of fixing means for fixing the transferred toner image to the recording medium, and the distance in the conveyance direction between adjacent fixing devices is longer than the maximum length of the recording medium.

The operation of the invention according to claim 2 will be described.

The toner image formed by the toner image forming means is transferred onto the recording medium by the transfer means. The toner image is fixed on the recording medium to which the toner image is transferred by a plurality of fixing means. At this time, the distance in the conveyance direction between the adjacent fixing units is set longer than the maximum length of the recording medium. Therefore, it is possible to prevent wrinkles and image defects from occurring on the recording medium due to the leading end of the recording medium undergoing the fixing process by the fixing unit on the upstream side in the conveying direction entering the fixing unit on the downstream side in the conveying direction and performing the fixing process.

According to a third aspect of the present invention, in an image forming apparatus for forming an image on a recording medium by an electrophotographic method, a toner image forming means for forming a toner image and a transfer means for transferring the toner image on the recording medium. And a plurality of fixing means for fixing the transferred toner image on the recording medium, and a control means for setting a parameter of the fixing means based on input image-related data.

The operation of the invention according to claim 3 will be described.

The toner image formed by the toner image forming means is transferred onto the recording medium by the transfer means. The toner image is fixed on the recording medium to which the toner image is transferred by a plurality of fixing means. At this time, the control means sets the fixing parameter based on the image-related data input to the apparatus. That is, the parameters of the fixing unit (fixing frequency, fixing speed, fixing temperature, etc.) are adjusted by determining the amount of toner constituting the transferred toner image and the air permeability of the recording medium based on the image-related data. Then, the toner image is satisfactorily fixed on the recording medium. That is, the toner image can be satisfactorily fixed on the recording medium regardless of the amount of toner and the type of recording medium.

The invention according to claim 4 is characterized in that, in the invention according to claim 3, the image-related data is an image density of the image.

The operation of the invention according to claim 4 will be described.

The fixing parameter for favorably fixing the toner image varies depending on the image density (the number of pixels to be imaged / the total number of pixels).

When the image density is high, for example, when it is necessary to form the light non-transmissive portion like a meter panel for automobiles, the fixing parameters (fixing temperature, fixing pressure, number of fixings, etc.) are increased. There is a need. On the other hand, when a toner image having a low image density is fixed by the fixing device located at the most downstream side in the conveyance direction in which a fixing parameter for fixing a toner image having a high image density is properly fixed, peeling (offset) of the toner layer occurs It cannot be satisfactorily fixed on the recording medium.

Therefore, for example, when the image density is high, the fixing is performed twice, and when the image density is low, the fixing is performed only once on the upstream side in the conveying direction. Is to be fixed in.

According to a fifth aspect of the invention, in the third aspect of the invention, the image-related data is a transfer bias value for the recording medium.

The operation of the invention of claim 5 will be described.

The transfer bias (current in the case of a constant voltage, voltage in the case of a constant current) value changes depending on the amount of toner constituting the toner image transferred to the recording medium. Therefore, the control unit changes the fixing parameter based on the transfer bias value, so that the toner image can be satisfactorily fixed on the recording medium regardless of the change in the amount of toner forming the toner image.

According to a sixth aspect of the invention, in the third aspect of the invention, the image-related data is recording medium information on which an image is formed.

The operation of the invention according to claim 6 will be described.

For example, the conditions under which blisters occur during fixing (fixing parameters) differ depending on the air permeability of the recording medium. Therefore, the control means controls the recording medium information, for example,
By changing the fixing parameters based on the type, thickness, air permeability, etc. of the recording medium, the toner image is satisfactorily fixed on the recording medium while reliably avoiding the occurrence of blisters.

According to a seventh aspect of the invention, in the invention according to any one of the third to sixth aspects, the parameter of the fixing means is the number of times of fixing.

The operation of the invention described in claim 7 will be described.

By changing the number of times of fixing depending on the image-related information, it is possible to satisfactorily fix the toner images having different image-related information. For example, when the image density is low or the air permeability of the recording medium is low, the number of fixings is reduced, and when the image density is high or the air permeability of the recording medium is high, the number of fixings is increased. It is possible to satisfactorily fix toner images having different image-related information while avoiding blisters at a transport speed that does not impair production efficiency.

The invention according to claim 8 is characterized in that, in the invention according to any one of claims 3 to 6, the parameter of the fixing means is a fixing speed.

The operation of the present invention will be described.

By changing the fixing speed according to the image-related information, the toner images having different image-related information can be fixed well. For example, when the image density is low or the air permeability of the recording medium is low, the fixing speed is increased, and when the image density is high or the air permeability of the recording medium is high, the fixing speed is decreased. It is possible to satisfactorily fix toner images having different image-related information while avoiding blisters at a transport speed that does not impair production efficiency.

The invention of claim 9 is characterized in that, in the invention of any one of claims 3 to 6, the parameter of the fixing means is a fixing temperature.

The operation of the invention according to claim 9 will be described.

By changing the fixing temperature according to the image-related information, the toner images having different image-related information can be fixed well. For example, by lowering the fixing temperature when the image density is low, and by increasing the fixing temperature when the image density is high, toner having different image-related information while avoiding blisters at a transport speed that does not impair production efficiency. Each image can be fixed well.

[0041]

DETAILED DESCRIPTION OF THE INVENTION An image forming apparatus according to an embodiment of the present invention will be described.

The image forming apparatus 10, as shown in FIG.
A main body 6 for laminating toner images of respective colors, transferring the toner images onto a special film described later, and primarily fixing the transferred toner images.
0 and the toner image that was primarily fixed is fixed again (secondary fixing)
A secondary fixing device 62, and a conveyor belt 64 that conveys the special film from the main assembly 60 of the apparatus to the secondary fixing device 62.
A paper discharge tray 66 on which a special film on which a toner image is secondarily fixed is laminated, and a paper discharge that is disposed between the apparatus main body 60 and the secondary fixing device 62 and stores the special film discharged without secondary fixing. And a tray 58.

As shown in FIG. 2, the apparatus main body 60 has an image processing section 12 for inputting image-related information and drivingly controlling each section described later, and a toner image of each color according to a drive signal from the image processing section 12. Image forming unit 14 for forming
And a transfer unit 16 for transferring a toner image to a special film, which will be described later, and a supply unit 18 for supplying the special film to the conveyance path.
And a primary fixing unit 2 for fixing the toner image on a special film
0, and a switching plate 22 for transporting the special film on which the toner image is primarily fixed to the secondary fixing device 62 or switching the discharge to the discharge tray 58.

The toner image forming section 14 forms toner images of white (W), black (K1), red (R), and black (K2), respectively.
R, 14K2 (hereinafter referred to as 14W to 14K2; other reference numbers are also the same).

Here, the recording color is black twice because, as will be described later, when a meter panel or the like is manufactured, a large amount of light is formed in order to form a portion that does not transmit light (light non-transmission portion). This is because black toner must be formed on the special film. Other recording colors may be different recording colors as long as the colors used in this meter panel are white and red.

The toner image forming portions 14W to 14K2 are respectively provided with chargers 2 around the photosensitive drums 24W to 24K2.
6, an optical scanning device 28, a developing device 30, a primary transfer device 32, and a toner removing blade 34 are provided. The photosensitive drums 24W to 24K2 are charged by the charger 26 by being rotated clockwise in FIG. 1, and electrostatic latent images are formed by the scanning of the laser beams 36W to 36K2 of the optical scanning device 28, and the electrostatic latent images are formed. In the configuration, the toner images of the colors corresponding to the respective image signals are formed by the developing device 30 on the portions where the electric latent images are formed.

The transfer portion 16 is wound around three rollers 38 and is rotatably arranged counterclockwise in FIG. 1, and an intermediate transfer belt 40, and a toner image formed on the photosensitive drums 24W to 24K2. Is transferred to the intermediate transfer belt 40, and a secondary transfer unit 44 for transferring the toner image transferred on the intermediate transfer belt 40 to a special film.

The special film transport system is constructed so that the special film can be discharged from the supply unit 18 to the switching plate 22 via the secondary transfer unit 44 and the primary fixing unit 20.

The primary fixing section 20 includes a heat drum 48,
It is composed of a pressure bonding belt 50 that conveys the special film while pressing the special film against the heat drum 48 by the pressing force of the pressing pad 49, and fixes the transferred toner image on the special film. Here, the surface temperature of the heat drum 48 is set to the minimum temperature T1 ° C. at which the image can be fixed on the special film without lowering the transport speed when the image for forming the meter panel is formed on the special film. ing.

The special film referred to here is a base material for forming a meter panel or the like, and has a predetermined strength and is formed transparent or semitransparent for transmitting light. Is.

Further, between the secondary transfer portion 44 and the primary fixing portion 20, there are decelerating conveying belts 46A and 46B for reducing the conveying speed of the special film in two steps in order to adjust the processing speed difference therebetween. It is arranged.

Further, as shown in FIG. 1, the switching plate 22 is configured to be able to switch between a solid line position and a broken line position, and the special film primarily fixed at the solid line position is attached to the secondary fixing device 62. Along with the guide, it is configured to guide to the paper discharge tray 58 at the position of the broken line.

On the other hand, the secondary fixing device 62 arranged on the downstream side of the apparatus main body 60 in the conveying direction is composed of a heat roll 68 and a pressure roll 70, and the pressure roll 70 forms an image forming surface of a special film. The toner image is fixed on the special film by being pressed by the heat roll 68 and being heated by the heat roll 68.

The surface temperature of the heat roll 68 does not impair the processing efficiency. For example, the toner image on which the light opaque portion of the meter panel is formed is transferred to the special film at the same transfer speed as the transfer speed of the primary fixing section 20. It is set to a temperature T2 ° C. (> T1 ° C.) at which the toner can be properly fixed.

A case where a meter panel of an automobile is produced by the image forming apparatus 10 configured as described above will be described.

As a meter panel of an automobile, a type in which a warning light is turned on by a backlight is generally used. In this case, there are a light non-transmissive portion that does not transmit the light of the backlight and a light transmissive portion that transmits the light of the backlight. In this light transmitting portion, a transparent portion that allows the backlight to pass through and a coloring portion (highlight portion) that develops a predetermined color.
There is.

Hereinafter, a case where an image is formed in each of the light opaque portion, the transparent portion, and the highlight portion will be described.

First, when the light non-transmissive portion is formed, the image processing portion 12 outputs an output signal of 100% to each of the chargers 26 of the toner image forming portions 14K1 and 14K2. Here, the output refers to the maximum / minimum transmission density of the image of each color formed on the special film when the potentials of the photoconductor drums 24W to 24K2 due to the charging from the charger 26 of each color are maximized / minimized. Is the ratio of the transmission density of the image formed (output = [(transmission density-minimum transmission density) / (maximum transmission density-minimum transmission density)] × 100
(%)). However, in the case of this embodiment, black (K
(Color) has a toner image formed at two locations, so it is formed on a special film when both the potentials of the photoconductor drums 24K1 and 24K2 due to the charging of both toner image forming portions 14K1 and 14K2 are maximized / minimized. The ratio of the transmission density of the formed image to the maximum / minimum transmission density of the K-color image will be referred to.

In this way, by inputting a signal with an output of 100%, the maximum transmission density (maximum thickness) is obtained.
The toner layers (toner images) of K1 and K2 are formed on the photosensitive drums 24K1 and 24K2, and the intermediate transfer belt 4
By being stacked and transferred to 0, a thick K color toner layer which does not transmit light is formed.

Next, when forming a blank portion, the image processing section 12 outputs a signal of 0% output to the chargers 26 of the toner image forming sections 14W to 14K2. As a result, an image is not formed on the portion of the special film, and a portion (blank portion) where the backlight is bare is formed.

Finally, the case of forming a highlight portion will be described. The highlight portion outputs a signal having a predetermined transmission density, for example, a signal of 20% output, to the toner image forming portion of the color, for example, the charger 26 of the toner image forming portion 14R so that the color is developed in a predetermined color. Output. As a result, an R color toner layer (toner image) having a predetermined transmission density is formed on the photoconductor drum 24R. When forming a highlight portion of K color with a predetermined transmission density, for example, by outputting signals of the same output value to the toner image forming portions 14K1 and 14K2, the photosensitive drums 24K1 and 24K are output.
The toner images of 2 are formed and stacked on the intermediate transfer belt 40 to form a toner image of a predetermined transmission density.

In this way, the photosensitive drum 24K1,
Each toner image formed on 24K2 is transferred to the primary transfer device 32.
Is transferred onto the intermediate transfer belt 40 in a laminated manner, and further transferred onto the special film conveyed from the supply section 18 by the secondary transfer device 44.

By the way, the image processing section 12 switches the number of fixings based on the image data. That is,
The image density of each image data (the number of pixels forming an image / the total number of pixels) is detected, and when this image density is equal to or more than a threshold value (for example, 5%), it is determined to be a meter panel, and fixing is performed twice. It is determined to be performed, and the switching plate 22 is positioned at the solid line position.

Therefore, the special film on which the toner image is transferred is conveyed to the primary fixing section 20 by the decelerating conveyance belts 46A and 46B, and the surface temperature is set to the minimum temperature T1 ° C. at which the fixing is not defective. Then, it is pressed by the pressure bonding belt 50 (pressing pad 49) to perform the primary fixing. At this time, the special film has high air permeability,
The light-impermeable portion has a thick toner layer because toner layers of 100% output for K1 and K2 colors are laminated, but since the toner is fixed at the minimum surface temperature T1 ° C., the gas in the toner layer gradually increases. It is possible to prevent the blister from being generated by being discharged.

Thus, the toner image is primarily fixed (assumed)
The special film thus formed is conveyed to the secondary fixing device 62 via the switching plate 22 and the conveying belt 64. Secondary fixing device 6
In 2, the special film is pressed against the heat roll 68 by the pressure roll 70 and fixed. At this time, the surface temperature of the heat roll 68 is set to a temperature (T2 ° C.) at which the toner image is satisfactorily fixed even if a thick toner layer such as a light opaque portion is formed. Is well fixed on the special film. Since most of the gas has already escaped from the toner layer during primary fixing,
Even if it is fixed by the heat roll 68 having a surface temperature of T2 ° C., there is no possibility of blister generation.

In this way, the fixing is carried out in two steps, and the fixing temperature (surface temperature) of the secondary fixing device 62 (heat roller 68) on the downstream side (the most downstream side) in the conveying direction is good for the toner image on the meter panel. To a temperature (T2 ° C) at which
Primary fixing unit 20 (heat drum 48) upstream in the transport direction
By setting the fixing temperature (surface temperature) of (1) to the minimum temperature (T1 ° C. (<T2 ° C.)) at which fixing failure does not occur, the gas in the toner layer can be gradually discharged, and blister can be suppressed.

From the primary fixing section 20 to the secondary fixing device 6
The distance up to 2 is ensured to be longer than the maximum length in the transport direction of the special film, and the leading end of the special film being fixed in the primary fixing unit 20 enters the secondary fixing device 62 and the heat roll 68 and the pressure roll 70. Since the special film is prevented from being wrinkled or a defective image is caused by being sandwiched between the image film, the image processing unit 12 detects the image density from the input image data, and the image density is a threshold value. If it is below (for example, 5%), it is decided to set the number of times of fixing to one, and the switching plate 22 is switched to the sheet discharge tray 58 side (solid line position → dotted line position in FIG. 1).

As a result, the special film to which the toner image has been transferred is fixed to the primary fixing section 20 (heat drum 48 having a surface temperature T1 ° C.) and is discharged to the paper discharge tray 58. This is the minimum surface temperature T1 ° C at which fixing failure does not occur with a toner image having a high image density such as a meter panel.
However, if the toner image has a low image density, the toner can be surely melted and satisfactorily fixed on the special film.

When the special film on which the toner image having such a low image density is formed is conveyed to the secondary fixing device 62 for secondary fixing, the surface temperature T1 ° C. at which the image can be well fixed.
Since the fixing process is performed by the heat roll 68 having a surface temperature T2 ° C. higher than that, there is a problem that the toner image adheres to the heat roll 68 and is separated (offset) from the special film.

As described above, in the image forming apparatus 10 according to this embodiment, the primary fixing section 20 and the secondary fixing device 62 are provided,
For a meter panel transferred to a special film having a high air permeability by primary fixing with a heat drum 48 having a minimum surface temperature T1 ° C. that does not cause fixing failure at a conveying speed that does not impair processing efficiency in the primary fixing unit 20. Even with a high image density toner image (a toner layer with a thick light-impermeable portion), the gas is gradually discharged, and is not discharged all at once. Therefore, the occurrence of blisters can be suppressed. Further, the surface temperature T2 ° C. (>) at which the secondary fixing device 62 can satisfactorily fix
By fixing with the heat roll 68 at T1 ° C., a toner image with a thick toner layer can be satisfactorily fixed without generating blisters in the light opaque portion or the like. Therefore, it is possible to avoid the formation of a pinhole in the light opaque portion of the meter panel and ensure the concealing property.

In particular, fixing of a toner image in which a thick toner layer is formed on a special film having a high air permeability such as a meter panel can be satisfactorily carried out by preventing blisters.

In addition, by raising the fixing temperature in two steps to perform fixing as described above, good fixing can be performed without reducing the fixing processing speed (conveying speed) to avoid the occurrence of blister. It is possible to maintain high productivity of the meter panel that requires concealment.

By the way, when the number of times of fixing is set to one, the sheet is discharged to the sheet discharge tray 58. Therefore, when the image formed immediately such as the test pattern is checked, the sheet discharge tray 68 can be used. Even if it is not necessary to take it, it is convenient that it can be taken out immediately from the paper discharge tray 58 beside the apparatus main body.

In the present embodiment, the number of times of fixing is set to two, but it is not limited to this as long as it is plural.

In the present embodiment, the fixing temperatures of the plurality of fixing means (the primary fixing section 20 and the secondary fixing device 62) are increased toward the downstream side in the conveying direction, but the fixing pressure may be increased. .

Further, in the present embodiment, the switching plate 22 is used to change the number of fixings. However, by releasing the nip between the heat roll 68 and the pressure roll 70 of the secondary fixing device 62, the number of fixings of the special film is changed. Can be changed to once.

Furthermore, in the image forming apparatus of the present embodiment, the image density is detected based on the image data input to the image processing section 12, and the number of fixings is changed based on this image density. The method is also good. For example, the number of fixings may be changed by feeding back the transfer bias of the secondary transfer unit 44 to the image processing unit 12. this is,
Since the toner is a resistor, the current value fluctuates according to the amount of toner when transferring at a constant voltage. Further, if it is a constant current, the voltage value changes. Therefore, by changing the number of fixings in accordance with the change in the current value or the voltage value, the toner image can be fixed well regardless of the toner amount.

Further, although the case of forming an image on a special film has been described in the present embodiment, the present invention can be applied to the case of forming an image on a recording medium of a different type, for example, paper. In this case, the number of fixings is changed based on the recording medium information by inputting the recording medium information such as the type (air permeability) and the thickness of the recording medium to the image processing unit 12. Is also possible. As a result, the toner image can be satisfactorily fixed regardless of the type of recording medium.

Further, although the number of times of fixing is changed as the fixing parameter in the present embodiment, the fixing temperature and fixing speed of the primary fixing section 20 and the secondary fixing device 62 may be changed.

Further, the secondary fixing device 62 is of a two roll type consisting of the heat roll 68 and the pressure roll 70, but is not limited to this.

In this embodiment, the number of toner image forming units is four for the purpose of diverting the existing color image forming apparatus, but the present invention is not limited to this.

[0082]

According to the image forming apparatus of the present invention, the toner image can be satisfactorily fixed on the recording medium without impairing the processing speed.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram of a device body of the image forming apparatus according to the embodiment of the invention.

[Explanation of symbols]

10 image forming apparatus 14 Toner image forming unit (toner image forming means) 16 Transfer unit (transfer means) 20 Primary fixing section (fixing means) 62 Secondary fixing device (fixing means)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoko Miyamoto             Fuji Zero, 2274 Hongo, Ebina City, Kanagawa Prefecture             Co., Ltd. Ebina Office (72) Inventor Nowakazu Takahashi             Fuji Zero, 2274 Hongo, Ebina City, Kanagawa Prefecture             Co., Ltd. Ebina Office F-term (reference) 2H033 AA47 BA01 BA02 BA10 BA59                       BB00 CA16 CA18 CA23 CA27                       CA35 CA39 CA40

Claims (9)

[Claims] 1. An image forming apparatus for forming an image on a recording medium by an electrophotographic method, a toner image forming means for forming a toner image, a transfer means for transferring the toner image on the recording medium, and the transferred image. A plurality of fixing means for fixing the toner image to the recording medium, wherein the fixing temperature or the fixing pressure is increased for the fixing means located on the downstream side in the conveying direction of the recording medium among the plurality of fixing means. A characteristic image forming apparatus. 2. An image forming apparatus for forming an image on a recording medium by an electrophotographic method, a toner image forming means for forming a toner image, a transfer means for transferring the toner image on the recording medium, and the transferred image. An image forming apparatus comprising: a plurality of fixing units for fixing a toner image to the recording medium, and a distance in a conveyance direction between adjacent fixing devices is longer than a maximum length of the recording medium. 3. An image forming apparatus for forming an image on a recording medium by an electrophotographic method, a toner image forming means for forming a toner image, a transfer means for transferring the toner image on the recording medium, and the transferred image. An image forming apparatus comprising: a plurality of fixing means for fixing a toner image on the recording medium; and a control means for setting a parameter of the fixing means based on input image-related data. 4. The image forming apparatus according to claim 3, wherein the image-related data is an image density of the image. 5. The image forming apparatus according to claim 3, wherein the image-related data is a transfer bias value for the recording medium. 6. The image forming apparatus according to claim 3, wherein the image-related data is recording medium information on which an image is formed. 7. The image forming apparatus according to claim 3, wherein the parameter of the fixing unit is the number of times of fixing. 8. The image forming apparatus according to claim 3, wherein the parameter of the fixing unit is a fixing speed. 9. The image forming apparatus according to claim 3, wherein the parameter of the fixing unit is a fixing temperature.