JPH04122970A - Color image forming device - Google Patents

Abstract

PURPOSE:To obtain a device having an easy mechanism and also a compact size by performing the re-fixation of a transfer material on which the fixation is performed once by use of the fixing means of a main body. CONSTITUTION:When image forming is finished under an ordinary mode, an OHP button on an operation panel11 is depressed.And then, the transfer material on which the fixation is performed once is inserted into an opening part 38 after turning the transfer material over, and when the transfer material is still more inserted along a guide member 40, it is detected by a transfer material detecting sensor 37, and the signal is outputted to a controlling means. After the OHP button on the operation panel 11 is depressed and also after confirming that the transfer material on which the re-fixation is to be performed is set by the sensor 37, the re-fixation is performed. That means, the re-fixation sequence is actuated by the controlling means under a re-fixation mode where the fixation temperature is 200 deg.C and a transfer material carrying velocity by a paper re-feeding roller 34, a fixation roller 30 and a paper ejecting roller 31 is 30mm/sec., and after the transfer material is fed to the fixation roller 30 by the paper re-feeding roller 34, the re-fixation is performed, and then, the transfer material is ejected by the paper ejecting roller 31.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color image forming method in which a toner image is formed on an image carrier by electrophotography and transferred onto a transfer material to obtain a color image. Regarding equipment.

In particular, the present invention relates to color image forming apparatuses such as printers, copiers, facsimile machines, etc., which can form color images with excellent color reproducibility on transfer materials such as OHP films.

[Conventional technology]

Conventional color image forming apparatuses require excellent color toner images when forming color images on transfer materials, especially cardboard and OHP films (transparent film and synthetic resin recording media for overflow projectors). In order to obtain color reproducibility, it is necessary to dissolve the toner almost completely to eliminate irregularities on the surface of the toner layer and make the surface smooth, so the fixing conditions have been changed to fix the color toner image.

Methods for changing the fixing conditions include changing the fixing temperature and changing the fixing speed. The former method of changing the fixing temperature takes a long time to reach a predetermined temperature, and also tends to cause offset due to temperature changes.Additionally, simply increasing the temperature may result in poor color reproducibility. There are problems such as whether it is sufficient or not. On the other hand, the latter method of changing the fixing speed requires the distance from the transfer means to the fixing means to be longer than the transfer material, and also requires that the rear end of the previous transfer material and the front end of the subsequent transfer material be There is a problem in that the fixing speed can only be slowed down to such an extent that they do not overlap.

In any case, image formation using the method of changing the fixing temperature or fixing speed has excellent color reproducibility! Unable to obtain Yucolor image.

Taking these problems into consideration, the applicant has proposed
Japanese Patent No. 41767 discloses an image forming apparatus that can obtain a color image with excellent color reproducibility by conveying a transfer material that has been fixed by a transfer material conveyance means to be fixed again. is suggesting.

[Problem that the invention seeks to solve]

However, in the image forming apparatus disclosed in the above-mentioned publication, the transfer material that has been fixed once is transported to the re-fixing transport path by the guide claw and then fixed again by the fixing means, so the structure of the transport path is However, it has the disadvantage that it is complicated and the device must also be larger.

The present invention has been made in order to solve the above-mentioned drawbacks, and an object of the present invention is to be able to re-fix a transfer material that has been fixed twice using a fixing means in the main body, with a simple mechanism, Moreover, it is possible to provide a compact color image forming apparatus. Another object of the present invention is to provide a color image forming apparatus equipped with a re-fixing mechanism that can improve gloss, light transmittance, and fixing performance when fixing of color images or OHP films is insufficient. be.

[Means for solving problems]

The above object is to provide a fixing means for fixing a toner image on a transfer material, a paper ejection means for ejecting the transfer material to the outside of the apparatus, and a fixing means for fixing a toner image on a transfer material, a paper ejection means for ejecting the transfer material to the outside of the apparatus, and a transfer means for discharging the toner image on the transfer material when the paper is ejected by the paper ejection means when in the first position. This is achieved by a color image forming apparatus characterized by having a movable storage means that can store the material, and a re-fixing feeding means that feeds the material to the stage.

〔Example〕

Next, the present invention will be described based on an embodiment shown in the accompanying drawings.

FIG. 1 shows a main cross section of a color printer to which the present invention is applied, viewed from the left side. [Apparatus body] O is surrounded by an operation panel 11, an openable and closable upper cover 12, a toner supply cover 13, a front cover 14, etc. on the front side, and inside there is a detachable process cartridge 15 and a paper feed power center 16. It is provided.

In FIG. 1, the photoreceptor belt 17, which is an image carrier, is
The belt has a visible photosensitive layer coated on its surface, and is stretched between a driving roller 18 and a driven roller 19. The drive roller 18 rotates (not shown) and conveys the photoreceptor belt 17 in a clockwise direction via a drive gear meshing with a gear provided on the main body 10 of the apparatus. Furthermore, the distance maintaining member 20 keeps the distance between the developing device 23 and the photoreceptor belt 17 constant, making it possible to form a stable and good image.

In this embodiment, the photoreceptor belt 17 is used as the image carrier, but the present invention is not limited thereto, and can be applied to existing image carriers having a photosensitive layer such as a photoreceptor drum.

A charging means 21, an exposing means 22, a developing means 23, a transferring means 24, and a cleaning means 25 are arranged around the photoreceptor belt 17.

The charging means is provided to uniformly charge the photosensitive layer on the surface of the photoreceptor belt 17 with a predetermined polarity, and is an existing charger 21 such as a corona belt or a Suflotron charger, and is used to charge the OPC photoreceptor. For this purpose, a scorotron charger is preferably used.

The exposure means is a semiconductor laser writing system unit 22, which exposes the surface of the photoreceptor belt 17 charged by the charger 21 to form an electrostatic latent image.

The developing means includes a plurality of developing devices 23a to 23d each containing a developer of a different color, for example, yellow magenta, yellow magenta, and black toner. Each of the developing devices 23a to 23d includes a developing sleeve 231a to 231d that maintains a predetermined gap with the photoreceptor belt 17, and a stirring screw 232a to 232d that stirs the toner of each color, and the electrostatic latent image on the photoreceptor belt 17. It has the function of making a toner image visible using a non-contact development method. Unlike the contact development method, this non-contact development method does not damage the toner image previously formed on the photoreceptor belt 17 and does not hinder the movement of the photoreceptor belt 17, so that it is possible to obtain a good color image. I can do it. The developing means is not limited to color development using four different color toners as in this embodiment, but is also applicable to monochromatic, two-color toner, etc.
Color or three color toners may be used, and in this case, the developing means includes as many developing devices as there are toner colors on the photoreceptor belt 1.
It may be arranged around 7.

The transfer means transfers the toner image formed on the photoreceptor belt 17 onto a transfer material using a transfer device 24 such as a transfer corona discharger. As this transfer means, an existing transfer member such as a transfer drum may be used instead of the transfer device 24.

The cleaning means 25 includes a cleaning blade 251
During the image forming process, the photoreceptor belt 17
It is maintained at a position spaced apart from the surface of the photoreceptor belt 17, and is provided so as to clean the photoreceptor belt 17 by pressing against the surface of the photoreceptor belt 17 during cleaning after transferring the toner image to the transfer material.

The collection box 26 is for collecting and storing residual toner on the photoreceptor belt 17 removed by the cleaning means 25 through a toner collection pipe 262 by a waste toner screw 261.

In this embodiment, the image forming section of the printer described above includes a photoreceptor belt 17, a charger 21, developing devices 23a to 23d containing toner of each color, and a cleaning means 25.
The process means sections of the toner collection box 26 are housed in the integrated process cartridge 15 to form a unit, and can be attached to and detached from the apparatus main body IO all at once. However, the process unit unitized within the process cartridge 15 is not limited to this.
At least the photoreceptor bell) 17 and the developing units 23a to 23d may be integrated into a unit, and other process sections may also be integrated into a unit.

The color image forming process by the color image forming apparatus having the above-described configuration is performed as follows.

The process cartridge 15 is loaded in a first position (described later) and is ready for image formation.

When the first color image signal output from the image reading device separate from the main body 10 is input to the laser writing system unit 22, a semiconductor laser (not shown) in the laser writing system unit 22 is used. A laser beam is generated.

The laser beam is rotated and scanned by a polygon mirror 221 rotated by a drive motor (not shown), and f
θ lens 222, linear lenses 224 and 3
The light is projected onto the circumferential surface of the photoreceptor belt 17, which has been uniformly charged to a predetermined charge by the charger 21, through a mirror 223 to form a bright line.

On the other hand, regarding the sub-scanning direction, a belt index corresponding to a specific position on the photoreceptor belt 17 is detected by a photo sensor (none of which are shown), or a print command Iz is received, and this detection or command signal is detected. The main scanning line on which the modulation of the semiconductor laser by the image signal is started is determined based on .

When scanning is started, in the main scanning direction, the laser beam is detected by an index sensor (not shown), and based on this detected signal, modulation of the semiconductor laser by the image signal of the first color is started. The modulated laser beam is scanned over the surface of the photoreceptor belt 17.

Therefore, main scanning by the laser beam and photoreceptor belt 1
A latent image corresponding to the first color is formed on the uniformly charged surface of the photoreceptor belt 17 by the sub-scanning during the conveyance of step 7. This latent image is developed by a developing device 23a containing yellow toner corresponding to the first color among the developing means.
A yellow toner image is formed on the surface of the photoreceptor belt 17. Thereafter, the photoreceptor belt 17 passes under the cleaning blade 251 which is spaced apart from the surface of the photoreceptor belt 17 while holding the yellow toner image on the surface thereof, and then begins to form an image of the second color. . That is, the photoreceptor belt 17 on which the yellow toner image has been formed is transferred to the charger 2.
1, the image signal of the second color is input to the laser writing system unit 22, and as in the case of the image signal of the first color described above, the image signal of the second color is applied onto the surface of the photoreceptor belt J7. is written and a latent image is formed. The latent image is developed by a developer 23b containing magenta toner as the second color. A magenta toner image is formed in the presence of a yellow toner image that has already been formed.

Similarly, after forming a latent image based on the image signal I of the third color, an ant toner image is formed in the developing device 23c that accommodates the ant toner, and furthermore, after forming a latent image based on the image signal of the fourth color, accommodating the black toner. A color toner image is formed on the surface of the photoreceptor belt 17 by aligning the black toner image on the surface of the photoreceptor belt h17 with the developing device 23d.

Developing sleeve 231a of each of these developing devices 23a to 23d
231d is applied with a direct current or even alternating current bias, and the photosensitive belt 171m whose base is grounded performs reversal development (jumping development) in a non-contact manner. Note that for this non-contact development, either a one-component developer or a two-component developer can be used. In addition, when using a one-component developer, the toner hopper (35) described later is not required, and downsizing can be achieved.
A developing method using a two-component developer is superior in terms of developer stability and is therefore preferable in terms of color reproduction.

Formed on the surface of the photoreceptor belt 170 as described above! : Color toner images are transferred from the paper feed cassette 16 to the paper feed roller 2.
7 and is transferred to a transfer material by a timing roller 28 in synchronization with the color toner image. The transfer device 24 performs transfer by applying a high-voltage power output having a polarity opposite to that of the toner.

The transfer material onto which the color toner image has been transferred in this way is reliably separated by the photoreceptor belt 17 that changes direction rapidly (with a small diameter curvature) along the drive roller 18, and is transported upward by the transport belt 29. Note that this conveyor belt 2
9 is provided with a suction means 291 to suck the material and then reliably convey it upward. After the toner on the transfer material is melted and fixed by the fixing roller 30, the transfer material is discharged onto the upper surface of the upper cover 11, which also serves as a paper discharge tray, by the paper discharge roller 31.

On the other hand, the photoreceptor belt 17 that has finished transferring the color toner image to the transfer material is further conveyed clockwise, and the cleaning means 25 brings the cleaning blade 251 into pressure contact.
The remaining toner is removed and cleaned. After cleaning is completed, the cleaning blade 251 separates from the photoreceptor belt 17 again, and a new image forming process begins.

In the color image forming apparatus configured as described above, the timing roller 28. Photoreceptor belt 17. The conveyance speed of the transfer material by the conveyance means such as the conveyance belt 29.

The fixing speeds of the fixing roller 30 and the paper ejection roller 31 are all 120 mm/see.
The fixing temperature is 180°C.

In addition, the toner used in the color copying machine of this example is made by dispersing dyes and pigments in Volustelle resin and pulverizing it to a size with a weight average particle size of 3 to 12 μm, and a softening point of about 140°C. I used something.

Furthermore, as a fixing means, the heat roller is made of an aluminum core coated with fluororesin and has a diameter of about 30 mm.
The pressure roller has an iron core coated with silicone rubber and has a diameter of about 30 mm, the heating lamp is a 600 W halogen lamp, and the total pressure exerted by the fixing roller 30 is 17 kg at 3°.

However, it goes without saying that the present invention is not limited to these.

The paper discharge tray 32, which is a part of the upper cover 12, has one end pivotally supported by the upper cover 12 by a rotatable rotation shaft 321, and the other end rotatably supported by the upper cover 12. It is latched to a notch portion of a latching member 322 that is attached to the latching member 322. Hereinafter, this state (FIG. 1) will be referred to as the paper discharge tray 32 being in the first position. When the paper discharge tray 32 is in the first position, the paper discharge tray 32 accommodates the transfer column base from which the paper is discharged from the paper discharge roller 31.

On the other hand, as shown in FIG. 2, by rotating the locking member 322 in the direction of the arrow to release the latching of the sheet discharge tray 32, the sheet discharge tray 32 is rotated along the rotation axis 321 in the direction of the arrow due to its own weight. It rotates around , and engages with the positioning member 33. Hereinafter, this state (FIG. 2) will be referred to as the paper discharge tray 32 being in the second position. When the paper discharge tray 32 is in the second position, the paper discharge tray 32 acts as a paper feed pressure to feed the transfer material to the paper refeed roller 34.

The position detection sensor 36 is a sensor that detects that the paper discharge tray 32 is in the second position, and various existing sensors using a micro switch, a photoelectric switch, a magnetic switch, etc. can be used.

Further, the transfer material detection sensor 37 is a sensor that detects that the transfer material to be re-fixed is placed on the paper discharge tray 32 at the second position, and is a sensor that uses a transmissive or reflective photocoupler. Various existing sensors using a non-contact type reed switch, a contact type microswitch, etc. can be used.

Next, using the color copying machine mentioned above, OHP film,
The case of forming a color image on a transfer material such as cardboard will be described with reference to FIGS. 1 to 3. FIG.

First, an image is formed on the transfer material in the normal mode described above, and the transfer material is ejected onto the paper ejection tray 32 located at the first position, which is a part of the upper cover 12.

When image formation is completed in the normal mode, the control means selects the OHP mode by pressing an OHP button (not shown) on the FI production panel 11. That is, the control means controls the heater of the fixing roller 30, which is the fixing means, to raise the temperature from 180° C. in the normal mode to 200° C. in the re-fixing mode, and also increases the temperature of the fixing roller 34. The conveyance speed of the transfer material by the fixing roller 30 and the paper ejection roller 31 is set to 120 mm/se in the normal mode.
Each drive system is set so that the speed is reduced from e to 30 mm/sec, which is in the re-fixing mode.

In addition, in the re-fixing mode, the control means controls the image forming process sections such as the charging means, the exposure means, the developing means, the transfer means, the cleaning means, and the paper feed roller 27. Timing roller 28. The conveying means such as the conveying belt 29 is made inactive. That is, at the time of refixing, since image formation is not performed, the control means controls so that the means necessary for image formation are inoperative, and only the means necessary for refixing are operated.

On the other hand, the hanging member 322 is rotated to move the paper discharge tray 32 from the first position to the second position. When the paper discharge tray 32 is located at the second position, that is, when one end of the paper discharge tray 32 collides with the positioning member 33, the position detection sensor 36 controls that the paper discharge tray 32 is located at the second position. Output a signal to the means.

Then, the transfer material that has been fixed once is turned over and placed on the paper discharge tray 32 at the second position. The transfer material placed on the paper discharge tray 32 is detected by a transfer material detection sensor 37, and the transfer material detection sensor 37 outputs its signal to the control means. The control means is configured such that the OHP button on the operation panel 11 is pressed, the position detection sensor 36 indicates that the paper discharge tray 32 is in the second position, and the transfer material detection sensor 37 indicates that the transfer material to be re-fixed is set. Make sure that the That is, the control means controls the fixing temperature to 200°.
C1 refeed roller 34. Fixing roller 30. Paper ejection roller 3
The conveyance speed of the transfer material for re-fixing according to step 1 is 30 mm/s.
The re-fixing sequence is activated in the re-fixing mode (re-fixing condition) of ee, the transfer material is fed to the fixing roller 30 by the re-feeding roller 34 and re-fixing is performed, and then the paper ejection roller 31
ejects the paper.

Note that the fixing temperature and transport speed in the normal mode or re-fixing mode illustrated in this example are merely examples, and may vary depending on the type of transfer material to be re-fixed, the desired gloss of the finished image, etc. Therefore, it is desirable to be able to change these values arbitrarily.

In addition, in this embodiment, the position detection of the paper discharge tray 32 by the OHP button press 1 position detection sensor 36 and the transfer material detection by the transfer material detection sensor 37 are all confirmed; after that, the re-fixing sequence is activated. However, the present invention is not limited to this, and mode selection and refixing/can operation may be performed by detecting one or more of these. In this case, OHP button, position detection sensor 36
．． It goes without saying that only the transfer material detection sensors 37 necessary for the above-described mode selection and re-fixing/can operation need be provided in the color image forming apparatus 10.

Further, although it may be possible to manually rotate the hanging member 322 that locks the paper ejection [32], by first pressing the OHP button, the control means rotates the latch member 322 to eject the paper. Dish 32 may be moved to the second position. Furthermore, the hanging member 322 shown in this embodiment is not required, and the paper discharge tray 32
A gear and a motor may be incorporated into the rotating shaft 321 of the paper discharge tray 32 to automatically move the paper discharge tray 32 between the first position and the second position.

FIG. 4 shows a color image recording apparatus as another embodiment to which the present invention is applied. In addition, the numbers in the same figure are
Unless otherwise specified, the configuration and functions are the same as those of the color image forming apparatus of the embodiment described above.

The upper cover 12 of this embodiment has an opening 38 in a part thereof, and a slide cover 39 is disposed as a shielding member for shielding the opening 38. Here, slide cover 3
9, the opening 38 is shielded by the opening 38
The states in which the slide cover 39 is in the first position and the state in which it is open are respectively referred to as the state in which the slide cover 39 is in the first position and the state in which the slide cover 39 is in the second position. That is, when the slide cover 39 is in the first position, it is when image formation is performed in the normal mode, and when it is in the second position, it is when re-fixing is performed in the re-fixing mode. Further, the position detection sensor 36 is a sensor that detects that the slide cover 39 is in the second position. Note that this shielding member is not limited to the slide cover 39, and may be in the form of a door.

On the other hand, below the opening 38 is a guide member 40 that guides the transfer material to be re-fixed. A transfer material detection sensor 37 and a paper refeed roller 34 are provided to detect the transfer material.

A case where a color image is formed on a transfer material such as an OHP film or cardboard using the above-mentioned color copying machine will be explained with reference to FIG.

First, like the color image forming apparatus described above, an image is formed on a transfer material in the normal mode, and the transfer material is discharged onto the upper cover 12.

When image formation is completed in the normal mode, by pressing the OHP button (not shown) on the FI production panel 11, the control means selects the OHP mode in the same way as in the previous embodiment.

On the other hand, the slide cover 39 of the upper cover 12 is slid from the 11 position to the second position. Slide cover 3
9 is located in the second position, i.e. the top cover 12
When the opening 38 provided at t opens, the position detection sensor 36 positions the slide cover 39 at the second position.
: Outputs a signal to the control means.

Then, the transfer material that has been fixed by -degree is turned over and inserted into the opening 38 . When the transfer material inserted into the opening 38 is further inserted along the guide member 40, the transfer material detection sensor 37
The transfer material detection sensor 37 outputs the signal to the control means. Control means c: The OHP button on the operation panel 11 is pressed, the slide cover 39 is in the second position by the position detection sensor 36, and the transfer material to be re-fixed is set by the transfer material detection sensor 37. Confirm that this is the case, and then re-establish. That is, the control means sets the fixing temperature to 200° C. and the paper refeed roller 34. Fixing roller 30°: The conveying speed of the transfer material to be re-fixed by the discharge roller 31 is set to a re-fixing mode (re-fixing condition) of 30 mm/see, the re-fixing sequence is activated, and the transfer material is re-fed to the fixing roller 30. After the paper is fed by the paper roller 34 and re-fixed, the paper is discharged by the paper discharge roller 31.

[Effects of the Invention] As detailed above, the present invention is a color image forming apparatus that forms an image on a transfer material such as an OHP film in a normal mode, and then loops and conveys the once-fixed transfer material to a fixing device again. .

As a result, the color image forming apparatus of the present invention performs re-fixing even when the color image is not sufficiently fixed, and furthermore, when re-fixing, the conveyance speed of the transfer material is slowed and the fixing temperature is increased, thereby reducing the image quality. Black (B)
K) component image area yellow (Y) toner, magenta (M
) Toner Cyan (C) The overlapping toners are sufficiently melted and mixed with each other, making it possible not only to form a color image with good saturation and good color balance, but also a color image with excellent gloss and light transmittance. can be obtained. In addition, the image forming section is not driven in the re-fixing mode,
Furthermore, since the transfer material that has been fixed once is directly supplied to the fixing device, the transfer material to be re-fixed can be re-fixed without touching the image carrier, that is, without damaging the image carrier. In addition, we have adopted a loop structure that uses both the paper output tray and the paper feed tray for refixing, allowing the image forming apparatus to be made more compact. Re-fixing with a simple mechanism of providing

[Brief explanation of drawings]

FIG. 1 is a diagram showing a main cross section of a color printer to which the present invention is applied, viewed from the left side. FIG. 2 is a diagram showing the color printer in the re-fixing mode from the left side. FIG. 3 is a control block diagram for re-fixing. Figure vg4 is a diagram showing a main cross section of a color printer as another embodiment to which the present invention is applied. 10...Device body 11...Operation panel 1
2...Top cover 15...Process cartridge 16...Cassette 17...Photoconductor belt 18...
... Drive roller 21 ... Charger 22 ...
Laser writing system unit 23...Developer
24...Transfer device 25...Cleaning means 26...Toner collection box 36...Protrusion member 37...Guide member 2
7... Paper feed roller 28... Timing roller 29... Conveyance belt 30... Constant row roller 31
... Paper ejection roller 32 ... Paper ejection tray 34 ...
・Paper refeed roller 36...Position detection sensor 37...
・・Transfer material detection sensor

Claims (4)

[Claims] (1) A fixing means for fixing the toner image on the transfer material, a paper ejection means for ejecting the transfer material to the outside of the apparatus, and the transfer material ejected by the paper ejection means when in the first position. a re-fixing feeding means for feeding the transfer material contained in the storing means to the fixing means for re-fixing when the storing means is in a second position; A color image forming apparatus comprising: (2) A fixing means for fixing the toner image on the transfer material, a paper ejection means for ejecting the transfer material out of the apparatus, and inserting the transfer material ejected by the paper ejection means into the apparatus. What is claimed is: 1. A color image forming apparatus comprising: an opening in which the transfer material is inserted through the opening; and a re-fixing and feeding means for feeding the transfer material inserted through the opening to the fixing means for re-fixing. The color image forming apparatus according to claim 2, further comprising: (3) a shielding member that shields the opening. (4) The color image forming apparatus according to claim 1 or 2, wherein fixing conditions are changed when fixing is performed again by the fixing means.