JPH08185087A - Image forming device - Google Patents

Abstract

PURPOSE: To prevent the deviation between a toner image and the ink image on a recording material from occurring by the contraction of the recording material by heating the toner image at the time of fixing. CONSTITUTION: The first image forming device 10 of the electrophotographic system for forming the toner image of black and white is arranged on the upstream side with respect to the transporting direction of the recording material P, the second image forming means 20 of the ink-jet system for forming the color ink image on the downstream side. The first image forming means 10 is provided with the fixing device 18 for fixing the toner image on the recording material P by pressurizing without heating. The fixing device 18 is constituted by holding the upper roller 18a in contact with the metallic lower roller 18b by the prescribed pressure. Since the fixing device 18 is not accompanied by heating, the recording paper P is prevented from contracting due to the evaporation of water content by heating at the time of fixing. Even in the case of forming the ink image by the recording head 23 overlapping the recording material P after the toner image forming, the deviation between the toner image and the ink image is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a plurality of image forming means of different image forming systems.

[0002]

2. Description of the Related Art In recent years, the demand for color image forming apparatuses has increased due to the colorization of information. As a color image forming apparatus, there are an electrophotographic type and an inkjet type color image forming apparatus. An electrophotographic color image forming apparatus is more expensive than a monochromatic image forming apparatus of the same type or an inkjet color image forming apparatus. On the other hand, an inkjet color image forming apparatus is mainly an apparatus that performs serial printing and is therefore inexpensive, but the image forming time (recording time) is long, and the image quality is electrophotographic due to ink bleeding or the like. Inferior to

Therefore, the advantages of each image forming method are taken into consideration, and as a practical and inexpensive color image forming apparatus, an electrophotographic single color (black) image forming means and an ink jet type color image forming means are combined. In addition, a color image forming apparatus (hereinafter referred to as "hybrid image forming apparatus") has been proposed.

FIG. 10 shows an overall schematic configuration diagram of a copying machine as a hybrid image forming apparatus. The configuration and operation will be briefly described with reference to FIG.

In this hybrid image forming apparatus, a plurality of image forming units having different image forming systems, that is, a first image forming unit 10 of an electrophotographic system for forming a black and white toner image are provided in a main body M of the apparatus. An inkjet type second image forming unit 20 for forming a color ink image, and a feeding / conveying unit 30 for feeding and feeding a recording medium (hereinafter referred to as a “recording material”) P and reading an original image. And an image reading unit 50 for performing.

In the first image forming means 10, a black and white toner image is formed on the recording material P. That is, first, the photosensitive drum 11 is rotationally driven in the direction of arrow R11, and the surface thereof is uniformly charged by the charger (charging device) 12. Subsequently, an electrostatic latent image is formed on the surface of the photosensitive drum 11. At this time, the surface of the photosensitive drum 11 is scanned by the laser scanner 13 based on the image information of the black portion in the image information of the original document (not shown) on the original placement table 52 read by the optical sensor 51 of the image reading unit 50. Done, which forms an electrostatic latent image. next,
Toner is attached to the electrostatic latent image on the photosensitive drum 11 by the developing device 14 to form a black and white toner image.

The toner image thus formed on the photosensitive drum 11 is transferred onto the recording material P by the transfer roller (transfer device) 15. The recording material P is supplied to the feeding / conveying unit 30.
The paper stored in the paper feed cassette 31 is supplied to the photosensitive drum 11 via the paper feed roller 32, the conveyance path 33, the registration roller 34, and the like.

The recording material P carrying an unfixed toner image by transfer on the surface is conveyed in the direction of arrow K1 and supplied to the fixing device 17. The fixing device 17 includes an upper fixing roller 17a and a pressure roller 17b pressed against the fixing roller 17a from below.
The fixing roller 17a includes a hollow aluminum material, and a heater 17c is disposed inside the fixing roller 17a. The fixing device 17 is a so-called heat fixing system. The recording material P includes a transfer roller 17a and a pressure roller 17
It is nipped and conveyed by b and is heated and pressed at this time to fix the unfixed toner image on the surface. By this fixing, the formation of a monochrome toner image on the recording material P by the first image forming means 10 is completed.

The photosensitive drum 11 after the toner image is transferred
Is the residual toner (transfer residual) on the surface of the cleaning device 1.
6 and is used for the next image formation.

Subsequently, the second image forming means 20 forms a color ink image. Document placing table 52
The image information of the upper document is read by the optical sensor 51 of the image reading unit 50 and sent as an electric signal to an image processing unit (not shown). Here, of the read color image information, printing is performed on the recording material P based on the color information excluding the black portion information already used in the toner image. The recording material P is sent to the printing unit 22 by the conveying roller 21, and here, as described above, the information of the black portion is removed by the color recording head 23 composed of three colors of cyan, yellow, and magenta. Color information is printed on the recording material P. Here, the print width of the recording head 23 is several mm.
The recording material P conveyed is stopped on the printing unit 22 with a width of several tens of mm, and the recording head 23 performs printing while moving in the left-right direction in the conveying direction of the recording material P (arrow K1 direction). . That is, this is a so-called serial printing method in which the recording material P is conveyed by the width printed by the recording head 23 and the next printing is performed.

The recording material P on which a color ink image based on the color information is formed by the recording head 23 is ejected onto the paper ejection tray 35 by the paper ejection roller 24, whereby one recording material P is ejected. The above-mentioned first image forming means 1
A black and white toner image of 0 and a color ink image of the second image forming unit 20 are formed.

FIG. 11 shows an example of a general color image created and used in an office or the like. In the figure, the characters are black and the shaded parts are colored. Color is often used to make black letters stand out or to make graphs easier to see. In addition, black characters include characters that are quite small. For such a color original, the hybrid image forming apparatus described above is effective, and characters such as black portions are recorded by an electrophotographic method with good image quality, so that considerably small characters are surely recorded. In addition, fine color image is not required for colorizing a graph or the like, and recording is performed by an inexpensive inkjet method. Therefore, the hybrid image forming apparatus as a whole can constitute an inexpensive and practical color image forming apparatus. You can say that you can.

In the case of a black and white original document, or when the original document itself is a color original document and color recording is not required, electrophotographic recording is sufficient, and ink jet serial printing is not necessary. Becomes As described above, in serial printing, the width of the recording head 23 can be reduced and the cost of the recording head 23 can be suppressed low, but there is a problem in that recording takes time. If only electrophotographic recording is performed without serial printing, high-speed recording is possible and it can be used in the same manner as an ordinary copying apparatus.

[0014]

However, the above-described hybrid image forming apparatus is a fixing device 1 of the thermal fixing system.
Since I am using No. 7, there was room to solve the following points.

Under normal circumstances, the recording material P contains water, and the recording material P is fixed in the fixing device 17 by this water.
It vaporizes due to its heating as it passes through. Therefore, the recording material P shrinks as shown in FIG. 12, and the electrophotographic ink image and the ink jet ink image may not be aligned with each other.

That is, in FIG. 11, the black characters that are regularly arranged inside the color image form the color image on the recording material P that has shrunk in FIG. 12 after the toner image is formed. The black portion may be displaced from the color image.

The shrinkage of the recording material P is not constant because the amount of water contained in the recording material P varies depending on the environment in which the image forming apparatus is installed. Therefore, for example, when a color image is formed by the inkjet second image forming unit 20, it is almost impossible to electrically correct the color image.

Further, since the recording by the ink jet method is serial printing, the recording material P is in a stopped state when being printed by the recording head 23. Therefore, in a small hybrid image forming apparatus,
The recording material P is stopped to be conveyed while being sandwiched by the fixing device 17. As a result, the nip portion of the recording material P is overheated, and the temperature may unnecessarily increase.

Therefore, according to the present invention, the images are properly aligned,
Another object of the present invention is to provide an image forming apparatus capable of preventing unnecessary heating of the recording material.

[0020]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has at least two image forming means having different image forming systems.
Of the first image forming unit and the second image forming unit
In the image forming apparatus in which the image forming unit is an electrophotographic image forming unit, the first image forming unit includes an image forming unit that attaches a toner image onto a recording medium, and an undetermined amount attached to the recording medium. And a fixing device for fixing the toner image in the attached state onto the recording medium by applying pressure without heating.

In this case, the first image forming means can be arranged on the upstream side in the conveying direction of the recording medium, and the second image forming means can be arranged on the downstream side.

The second image forming means may be an ink jet system in which the recording means ejects ink to perform recording. The recording means may include an electrothermal converter for generating thermal energy for ejecting ink, and the recording means uses the thermal energy applied by the electrothermal converter. Alternatively, the film may be ejected from the ejection port by utilizing the film boiling generated in the ink.

The second image forming means may be one that performs serial printing or a full multi-recording system that simultaneously performs printing on the entire width of the recording medium.

After the toner image is attached to the recording medium by the first image forming unit of the first image forming unit, the ink image can be formed on the recording medium by the second image forming unit.

The fixing device of the first image forming means may have a pair of pressure rollers that sandwich and convey a recording medium and supply the recording medium to the recording means of the second image forming means.

The second image forming means may form a color ink image.

[0027]

According to the above construction, the first image forming means fixes the toner image adhered on the recording material by the first image forming portion onto the recording material by the non-heating pressure applied by the fixing device. . That is, no heating is applied during fixing. Therefore, the moisture in the recording material does not evaporate during fixing, and the recording material does not contract due to the evaporation of the moisture. Therefore, after the toner image is formed on the recording material by the first image forming unit or before the image formation by the first image forming unit, another second image forming unit, for example, an inkjet type image forming unit. As a result, even when an ink image is formed on the recording material, the ink image and the above-mentioned toner image will not be displaced.

Similarly, since the fixing device is not heated, the recording material is not needed by the fixing device even when the fixing device is stopped while the recording material being image-formed is nipped by the fixing device. It is not heated.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. <Embodiment 1> FIG. 1 shows an overall schematic configuration of a copying machine as a hybrid image forming apparatus. The configuration and operation will be briefly described with reference to FIG. The image forming apparatus of this embodiment can perform both ink jet recording and electrophotographic recording, that is, “composite” or “multiplex” recording on the same recording material. Here, "composite" is a recording in which the ink image of the inkjet recording and the toner image of the electrophotographic recording do not overlap each other on the same recording material surface.
Overlapping records are called "multiplex".

In this hybrid image forming apparatus, a plurality of image forming means having different image forming systems, that is, a first image forming means 10 of an electrophotographic system for forming a black and white toner image are provided in the apparatus main body M. An inkjet type second image forming unit 20 for forming a color ink image, and a feeding / conveying unit 30 for feeding and feeding a recording medium (hereinafter referred to as a “recording material”) P and reading an original image. And a reading unit 50 for performing.

In the first image forming means 10, a black and white toner image is formed on the recording material P. That is, first, the photosensitive drum 11 is rotationally driven in the direction of arrow R11, and the surface thereof is uniformly charged by the charger (charging device) 12. Subsequently, an electrostatic latent image is formed on the surface of the photosensitive drum 11. At this time, the surface of the photosensitive drum 11 is scanned by the laser scanner 13 based on the image information of the black portion in the image information of the original document (not shown) on the original placement table 52 read by the optical sensor 51 of the image reading unit 50. Done, which forms an electrostatic latent image. next,
Toner is attached to the electrostatic latent image on the photosensitive drum 11 by the developing device 14 to form a black and white toner image.

The toner image thus formed on the photosensitive drum 11 is transferred onto the recording material P by the transfer roller (transfer device) 15. The recording material P is supplied to the feeding / conveying unit 30.
The paper stored in the paper feed cassette 31 is supplied to the photosensitive drum 11 via the paper feed roller 32, the conveyance path 33, the registration roller 34, and the like.

The recording material P carrying the unfixed toner image by transfer on the surface is conveyed in the direction of arrow K1 and supplied to the fixing device 18. The fixing device 18 includes an upper roller 18a and a lower roller 18b which are brought into contact with each other at a predetermined pressure. The recording material P is nipped and conveyed between the rollers 18a and 18b, so that the toner is recorded on the recording material P. Fix the image. The fixing device 18 will be described in detail later.

By this fixing, the formation of a black and white toner image on the recording material P by the first image forming means 10 is completed.

The photosensitive drum 11 after the toner image is transferred
Is the residual toner (transfer residual) on the surface of the cleaning device 1.
6 and is used for the next image formation.

Subsequently, the second image forming means 20 forms a color ink image. Document placing table 52
The image information of the upper document is read by the optical sensor 51 of the image reading unit 50 and sent as an electric signal to an image processing unit (not shown). Here, of the read color image information, printing is performed on the recording material P based on the color information excluding the black portion information already used in the toner image. The recording material P is sent to the printing unit 22 by the conveying roller 21, and here, as described above, the information of the black portion is removed by the color recording head 23 composed of three colors of cyan, yellow, and magenta. Color information is printed on the recording material P. Here, the print width of the recording head 23 is several mm.
The recording material P conveyed is stopped on the printing unit 22 with a width of several tens of mm, and the recording head 23 performs printing while moving in the left-right direction in the conveying direction of the recording material P (arrow K1 direction). . That is, this is a so-called serial printing method in which the recording material P is conveyed by the width printed by the recording head 23 and the next printing is performed.

The recording material P on which the color ink image based on the color information is formed by the recording head 23 is ejected onto the paper ejection tray 35 by the paper ejection roller 24, whereby one recording material P is ejected. The above-mentioned first image forming means 1
The black and white toner image of 0 and the color ink image of the above-described second image forming unit 20 are composite-recorded or multi-recorded.

The above-described fixing device 18 is a device for fixing the unfixed toner image transferred on the recording material P on the recording material P in the first image forming section, and is the apparatus main body M.
The lower roller 18b made of metal supported by the upper roller 18b and the upper roller 18a made of metal, which is also swingably supported. The upper roller 18a is biased by a pressure spring (not shown) and is in contact with the lower roller 18b with a predetermined pressing force. These upper roller 18a and lower roller 18b
In order to obtain a good fixing property of the toner image on the recording material P, each of them has a highly accurate surface finish so that each surface has no unevenness. Further, when the straightness of each of the upper roller 18a and the lower roller 18b is not high, the upper roller 18a and the lower roller 18b are not evenly contacted with each other in the axial direction (length direction) of the rollers 18a and 18b. The fixing performance varies. In order to prevent this, the straightness is also accurately finished.

Unlike the thermal fixing device that uses heat, the fixing device 18 having the above-described structure does not evaporate the moisture in the recording material P during fixing, so that the recording material P does not contract, and therefore, The black and white toner image formed by the electrophotographic first image forming unit 10 and the color image formed by the inkjet second image forming unit 20 are not displaced.

Further, since the second image forming means 20 carries out serial printing, even if the recording material P is stopped while being held by the fixing device 18, the fixing device 18 does not heat. The recording material P is not unnecessarily overheated.

Further, unlike a heat fixing device such as a heat fixing device which uses a halogen heater, it is not necessary to use a halogen heater, so that power consumption is reduced.
It is possible to significantly reduce the power consumption of the image forming unit.

In the pressure type fixing device 18 described above, the recording material P does not contract, but when the pressure is large, on the contrary, the recording material P does not contract.
Is known to be delayed. Therefore, in the hybrid image forming apparatus using the high-pressure fixing device 18, a good image having no positional deviation shown in FIG.
As shown in FIG. 2, image shift tends to occur. This is because the recording material P expands when the black toner image is fixed by the first image forming unit of the electrophotographic system, and the toner image also expands and shifts from its original position. This is because the color images are superposed by the image forming means.

However, this deviation amount (extension amount of the recording material P)
Depends largely on the pressure applied to the fixing device 18, and is less affected by the environment. Therefore, the elongation of the recording material P with respect to the standardized pressing force is constant, and by correcting the ink image of the inkjet method based on the elongation amount of the recording material P, the deviation from the toner image of the electrophotographic method is caused. Can be prevented. Specifically, for the recording material P, the ratio of the size after fixing to the initial size is measured, the print signal sent from the image processing unit to the recording head 23 is changed according to this ratio, and this printing is performed. That is, the ink image is formed based on the signal. As described above, this ratio does not change depending on the usage status of the hybrid image forming apparatus in the environment, and since each hybrid image forming apparatus is assembled under the same pressure, there is a difference between the image forming apparatuses. Nor. Therefore, a correction value based on this ratio may be incorporated in the image processing unit of the hybrid image forming apparatus in advance.

In FIG. 3, the recording material P is the second image forming means 2
FIG. 7 is a diagram showing a state in which the recording material P is stopped because the recording head P is conveyed to the 0 printing unit 22 and the first recording head 23 performs printing. Here, the transfer process of the recording material P has already been completed. That is, the trailing edge P ₁ of the recording material P has finished passing through the transfer nip portion N between the photosensitive drum 11 and the transfer roller 15. As a result, even if the recording material P is sequentially conveyed and stopped by serial printing, the laser scanner 1
3, the developing device 14, and the transfer roller 15 do not disturb the image formation of the black portion. <Second Embodiment> FIG. 4 shows a second embodiment of the present invention. In the second embodiment, the conveyance roller 21 between the fixing device 18 and the recording head 23 in FIG. 1 of the first embodiment is omitted.
That is, the fixing device 18 in FIG. 4 also functions as a conveyance roller.

In order for the recording head 23 to perform serial printing, it is necessary to convey the recording material P to the printing portion 22 with high accuracy in order to eliminate gaps and overlaps between the line prints.

For this reason, the transport roller 21 is a roller that requires high accuracy in its outer diameter and the like, and it takes time to process and is an expensive roller.

Further, as described above, the fixing device 18
The upper roller 18a and the lower roller 18b are finished with high accuracy in terms of surface property, straightness, etc. in order to perform good fixing.
Further, since it is metallic, it is possible to finish the outer diameter with high accuracy like the transport roller 21. Therefore, the upper roller 18a and the lower roller 18b of the fixing device 18 cannot be used as a substitute for the transport roller 21. It is possible enough. In the first and second embodiments, the transfer device 18
Applies pressure to the recording material P having the unfixed toner image on its surface, and therefore, it suffices to pass the recording material P between the rollers 18a and 18b. Therefore, in the fixing device 18 that also serves as the transport roller of the second embodiment, the operations of the rollers 18a and 18b may be the same as the operation of the transport roller 21 of the first embodiment.

As described above, by positively omitting the transport roller 21, the structure of the entire apparatus is simplified and the distance between the fixing device 18 and the recording head 23 can be shortened. It is also possible to promote miniaturization of the entire device. Of course, the price can also be reduced.

FIG. 5 is a front view showing a state where the upper roller 18a and the lower roller 18b of the fixing device 18 are in contact with each other. When the applied pressure is large, the rollers 18a and 18b are bent and a gap 18c is formed between the rollers 18a and 18b, resulting in defective fixing of the toner image on the recording material P. Will end up. Therefore, as shown in the perspective view of FIG. 6 and the top view of FIG. 7, the axis O _a of the upper roller 18 _a and the axis O _{b of the} lower roller 18 _b are not parallel to each other, and the angle θ
The method of constructing with is used.

Further, in the pressure type fixing device 18, both the upper roller 18a and the lower roller 18b are usually driven to rotate by a driving means (not shown). Therefore, the conveying direction of the recording material P of the roller pair having such an angle θ is the direction H perpendicular to the axis of each roller 18a, 18b.
_It is not _a , H _b , but the angle θ between them. The direction in which the recording material P is conveyed within the angle θ is determined by the difference in surface property between the rollers 18a and 18b, the difference in surface property between the front and back surfaces of the recording material P, and the like.

Therefore, in order to accurately convey the recording material P in the printing section 22 in the direction perpendicular to the direction in which the recording head 23 prints, the fixing device 18 is attached to the recording material by the fixing device 18. It is necessary to carry out so that the conveyance direction of P is perpendicular to the printing direction of the recording head 23 described above. On the contrary, first, the conveyance direction of the recording material P by the fixing device 18 is determined, and then, when the recording head 23 is arranged, the movement direction thereof may be perpendicular to the determined conveyance direction. Good. <Embodiment 3> FIG. 8 is a diagram showing Embodiment 3 of the present invention. As a recording head, a multi-type recording head 25 capable of simultaneously printing the entire width direction of the recording material P is used.
Recording heads 25 of three colors of cyan, yellow and magenta
It is composed of a, 25b, and 25c. The other configurations are the same as those in the first embodiment.

The recording head 25 requires a larger recording head than the recording head 23 of the serial printing type of the first embodiment, and the cost is high. However, when compared with the electrophotographic color image forming apparatus. Has
It can be constructed at low cost.

Further, since serial printing is not required, printing can be performed at the same speed as or a speed close to the recording speed of the electrophotographic system, so that a color image can be formed at a higher speed than in the first embodiment. Become. <Embodiment 4> FIG. 9 is a diagram showing Embodiment 4, and as in Embodiment 3, a multi-type recording head 25 is used as the recording head, and recording heads 25a of three colors of cyan, yellow, and magenta are used. , 25b, 25c. Other configurations are the same as those in the second embodiment. That is,
The transport roller 21 is removed from the configuration of the third embodiment shown in FIG. According to this configuration, since the recording heads 25a, 25b, 25c of the three colors are arranged at the constant interval L, the recording material P needs to be conveyed at a constant speed, and when the conveying speed of the recording material P is disturbed. The printing positions of cyan, yellow, and magenta are displaced, and the image is disturbed. Therefore, it is effective to use the metal upper roller 18a and the metal lower roller 18b which are finished with high precision as a substitute for the transport roller 21 as shown in the second embodiment. In other words, the fourth embodiment is a combination of the configurations of the second embodiment shown in FIG. 4 and the third embodiment shown in FIG. 8, and has both of the actions and effects.

The conveying direction of the recording material P by the fixing device 18 must be perpendicular to the nozzle moving direction of the multi-type recording head 25.
Or the mounting of the multi-type recording head 25 may be adjusted accordingly.

Further, in the third and fourth embodiments,
The recording speed of the printing unit 22 of the second image forming unit 20 may be slower than the recording speed of the first image forming unit 10. Since the recording speed in the printing unit 22 depends on the ink ejection frequency of the multi-type recording head 25, there is a limit to the ink ejection frequency for stable ejection. For this reason, it is desirable that the transfer of the toner image on the photosensitive drum 11 by the transfer roller 15 is completed at the rear end of the recording material P by the multi-type recording head 25 before recording is started.

In the above-described first to fourth embodiments, a copying apparatus was used as the hybrid image forming apparatus, but the present embodiment is applicable to a printer apparatus, a fax machine or the like for recording on the recording material P. Even if used, the same effect can be obtained.

Further, although the color recording section is described by using the ink jet system, an inexpensive color recording device such as a thermal transfer system may be used. However, the inkjet print head has a simple structure and is inexpensive in printing cost, which is effective in reducing the size and cost of the apparatus.

The present invention brings excellent effects particularly in a recording apparatus using an inkjet recording head for recording by forming flying droplets by utilizing thermal energy among the inkjet recording methods.

With regard to its typical structure and principle, for example, US Pat. Nos. 4,723,129 and 4740 are applicable.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, liquid (ink)
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path in which is stored, a rapid temperature rise corresponding to the recorded information and exceeding nucleate boiling is applied. , It is effective because it generates heat energy in the electrothermal converter and causes film boiling on the heat-acting surface of the recording head, resulting in the formation of bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis. Is. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. U.S. Pat. Nos. 4,558,333 and 44,596 disclosing a configuration in which a heat acting portion is arranged in a bending region.
The configuration using the specification No. 00 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the structure corresponding to the discharging portion is disclosed in Japanese Patent Laid-Open No. 59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the main body of the apparatus or the electrical connection to the main body of the apparatus and the ink from the main body of the apparatus by being mounted on the main body of the apparatus. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add the ejection recovery means of the recording head, the preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. Specific examples thereof include preheating for heating the recording head by using a capping unit, a cleaning unit, a pressurizing or suctioning unit, an electrothermal converter or a heating element other than this, or a combination thereof. Means and preliminary ejection means for performing ejection different from recording can be mentioned.

Regarding the type or number of recording heads to be mounted, two or more recording heads may be provided corresponding to a plurality of inks having different recording colors and densities. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode of only the mainstream color such as black, but it may be either a recording head is integrally formed or a combination of a plurality of recording heads is used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to adjust the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy for changing the state of the ink from the solid state to the liquid state, or to prevent the ink from evaporating, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, the ink is liquefied by applying heat energy according to the recording signal,
The present invention is also applicable to the case of using an ink that has a property of liquefying only when heat energy is applied, such as one that ejects liquid ink or one that already begins to solidify when it reaches a recording medium. In such a case, the ink is retained as a liquid or solid in the recesses or through holes of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, it may be configured to face the electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as the form of the ink jet recording apparatus of the present invention, other than the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function can be used. It may be a form or the like.

[0067]

As described above, according to the present invention,
Since one of the plurality of image forming units is the first image forming unit of the electrophotographic system and has the fixing device for fixing the toner image on the recording medium by applying pressure without heating, heating at the time of fixing is performed. This makes it possible to prevent the recording medium from shrinking. Therefore, even when the toner image formed by the first image forming unit on the recording medium is overlaid with the ink image by another image forming unit, for example, the image forming unit of the inkjet system, the toner image and the ink image are not formed. It is possible to prevent the occurrence of image shift.

Further, when the ink image is formed after the toner image is fixed, the fixing device is not heated, and therefore, when the recording medium is stopped while being held by the fixing device when the ink image is formed on the recording medium. However, unnecessary heating is not applied to the recording medium. For this reason,
The distance between the fixing device and the ink image printing portion can be shortened to simplify the configuration of the entire device. Further, fixing by pressure can reduce power consumption as compared with fixing by heating.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a hybrid image forming apparatus according to a first embodiment.

FIG. 2 is a diagram showing a state in which an image shift between a toner image and an ink image occurs due to the elongation of a recording material.

FIG. 3 is a diagram illustrating a state in which an ink image is formed on a recording material in the hybrid image forming apparatus according to the first exemplary embodiment.

FIG. 4 is a schematic configuration diagram of a hybrid image forming apparatus according to a second embodiment.

FIG. 5 is a front view of an upper roller and a lower roller of the fixing device according to the second exemplary embodiment.

FIG. 6 is a perspective view of an upper roller and a lower roller of the fixing device according to the second exemplary embodiment.

FIG. 7 is a top view of an upper roller and a lower roller of the fixing device according to the second exemplary embodiment.

FIG. 8 is a schematic configuration diagram of a hybrid image forming apparatus according to a third embodiment.

FIG. 9 is a schematic configuration diagram of a hybrid image forming apparatus according to a fourth embodiment.

FIG. 10 is a schematic schematic configuration diagram of a conventional hybrid image forming apparatus.

FIG. 11 is a diagram showing a state in which there is no image shift between a toner image and an ink image.

FIG. 12 is a diagram showing a state in which an image shift has occurred between a toner image and an ink image.

[Explanation of symbols]

10 First Image Forming Means (Electrophotographic Image Forming Means) 11 Photosensitive Drum 12 Charging Roller 13 Laser Scanner 14 Developing Device 15 Transfer Roller 16 Cleaning Device 18 Fixing Device 18a Upper Roller 18b Lower Roller 20 Second Image Forming Means (Inkjet image forming means) 21 Conveying roller 22 Printing unit 23 Recording head 24 Paper discharging roller

Claims (10)

[Claims] 1. At least two image forming units having different image forming systems are provided, and the first image forming unit of the first image forming unit and the second image forming unit is an electrophotographic system. In the image forming apparatus, which is an image forming unit, the first image forming unit unheats an image forming unit that attaches a toner image on a recording medium and an unfixed toner image that is attached on the recording medium. An image forming apparatus, comprising: a fixing device for fixing the recording medium onto the recording medium by applying pressure. 2. The first image forming means is arranged on the upstream side in the conveying direction of the recording medium, and the second image forming means is arranged on the downstream side. Image forming apparatus. 3. The image forming apparatus according to claim 2, wherein the second image forming unit is an inkjet system in which the recording unit ejects ink to perform recording. 4. The image forming apparatus according to claim 3, wherein the recording unit includes an electrothermal converter for generating thermal energy for ejecting ink. 5. The recording means causes the ink to be ejected from an ejection port by utilizing the film boiling generated in the ink by the thermal energy applied by the electrothermal converter. Image forming apparatus. 6. The image forming apparatus according to claim 3, wherein the second image forming unit performs serial printing. 7. The image according to claim 3, wherein the second image forming unit is a full multi-recording system that performs printing on the entire width of the recording medium at the same time. Forming equipment. 8. The ink image is formed on the recording medium by the second image forming unit after the toner image is attached to the recording medium by the first image forming unit of the first image forming unit. The image forming apparatus according to any one of claims 3 to 7. 9. The fixing device of the first image forming unit includes a pressure roller pair that holds and conveys a recording medium and supplies the recording medium to the recording unit of the second image forming unit. The image forming apparatus according to any one of claims 3 to 8. 10. The image forming apparatus according to claim 3, wherein the second image forming unit forms a color ink image.