JPH10198119A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device by which printing speed in the case of color printing or in the case of single color printing such as monochrome printing can be accelerated. SOLUTION: In this orthogonal transfer system image forming device, a toner image carried on a toner image carrier 1 stretched in the direction perpendicular to the carrying direction of printing paper 5 by plural rollers is transferred to the paper 5 in the direction perpendicular to the carrying direction of the paper 5 by a transfer counter roller 4 and the toner image transferred to the paper 5 is fixed. The device is constituted so that respective developing means 20C-20B for plural colors which attaches toner to the carrier 1 may be arranged along the rotating direction of the carrier 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an orthogonal transfer type image forming apparatus for transferring a toner image onto a printing paper in a direction perpendicular to a conveying direction of the printing paper.

[0002]

2. Description of the Related Art In recent years, toner-type image forming apparatuses capable of forming clear images with excellent resolution, such as laser printers, have become widespread. Among such toner-type image forming apparatuses, Japanese Patent Application No. 7-328600.
As described above, the orthogonal transfer type image forming apparatus that moves the toner image carrier in a direction orthogonal to the transport direction of the printing paper and transfers the toner image in small steps at a time is a small-sized product due to its configuration. It is very suitable for promoting the conversion.

[0003] A conventional image forming apparatus which is compatible with color by the orthogonal transfer system will be described below.

FIG. 9 is a schematic structural view of a conventional image forming apparatus, FIG. 10 is a perspective view showing a transfer process of the conventional image forming apparatus, and FIG. 11 is a view showing a toner layer of a developing roller of the conventional image forming apparatus. It is a schematic diagram which shows a formation state. And FIG.
FIG. 15 to FIG. 15 are schematic diagrams showing a transfer state of the conventional image forming apparatus.

In FIG. 9 and FIG. 10, a toner image carrier 1 composed of a photoreceptor belt whose surface is coated with a layer of an organic photoconductive material comprises a plurality of support rollers 2, displacement rollers 3, transfer opposing rollers 4, and the like. These rollers are stretched in the direction perpendicular to the direction in which the printing paper 5 is conveyed by the rollers, and rotate in the direction of an arrow during image formation, whereby a toner image is formed on the surface of the toner image carrier 1. Around the toner image carrier 1, charging means 6, developing means 7, cleaning means 8, static elimination means 9 and the like are arranged, and an upper portion of the toner image carrier 1 is exposed to laser light. Means 10 are arranged. As shown by the arrow in FIG.
Rotates in the direction perpendicular to the transport direction of the printing paper 5,
The portion passing through the charging means 6 is uniformly charged to about -600V. Exposure means 10 includes cyan, magenta, yellow,
Based on the image signals of the four primary colors of black, the surface of the toner image carrier 1 is irradiated on one line with laser light corresponding to the four primary colors. The potential of the portion irradiated with the laser beam is -1
By increasing the voltage to about 00 V, electrostatic latent images divided into four for each primary color are simultaneously formed on the surface of the toner image carrier 1. When the four primary colors of toner are pressed against the portion where the electrostatic latent image is formed by the developing roller 11, the toner image carrier 1
The toner images of each of the four primary colors that have become visible images appear one after another.

As shown in FIGS. 9 and 10, the developing means 7 comprises four parts for each primary color.
Is cyan, the developing means 7M is magenta, the developing means 7Y is yellow, and the developing means 7B is black.
Four primary color toner layers of yellow and black are formed on a common developing roller 11 so as to be divided into four for each primary color. FIG.
As shown in FIG. 1, toner layers 12 of four colors of cyan, magenta, yellow, and black are formed on the developing roller 11 from the right, and the toner layers 12 are separated by a gap 13 or a gap 14 to prevent color mixing. This gap 1
The portions 3 and 14 are sealed by the sealing materials 15 and 16, so that the toner does not normally adhere thereto. As shown in FIGS. 12 to 15, the toner image carrier 1 has a developing area of each color developed by the developing means 7 and a non-developing area sandwiched between the developing areas. Each color is set the same. In particular, FIGS.
In No. 5, the width of the development area and the width of the non-development area are set to 1: 1.

As shown in FIG. 10, the orthogonal transfer type image forming apparatus is characterized in that the rotation of the toner image carrier 1 and the conveyance of the printing paper 5 are temporarily stopped during the transfer, and the printing is stopped. The toner image carrier 1 is transferred onto the sheet 5 by the transfer opposing roller 4.
Is displaced by being rubbed with the movement of the object. At this time, the displacement roller 3 is displaced following the movement of the transfer facing roller 4 in order to eliminate the slack of the toner image carrier 1.

Whenever the transfer for one process is completed, the transfer opposing roller 4 passes over the printing paper 5 and moves out of the area of the printing paper 5, so that the toner image carrier 1 is separated from the printing paper 5. . Then, the transport of the printing paper 5 is started, but the transporting distance of the printing paper 5 is only the width of the developing area of each color of the toner image carrier 1 represented by the toner layer of each color shown in FIGS. . The printing paper 5 is intermittently sent to the fixing means 17 by the width of the development area of each color, and the fixing means 17 applies the printing paper 5 on which the image is transferred to a pressure roller 18 and a heating roller 19 having a heat source inside. The toner particles are melted and fixed on the printing paper 5.

The method of forming a color toner image starts from the state shown in FIG. 12, but in the first transfer, only a {cyan} toner image is transferred in one step.
In the column, only the cyan toner image is transferred. When the printing paper 5 is conveyed by the width of the development area, the second transfer is performed. However, even in the second transfer, only the cyan image is transferred in one process, so that the cyan in the second column is also transferred. Is transferred.

Next, as shown in FIG. 13, in the third transfer, a {cyan, magenta} toner image is transferred in one step, so that the {cyan, magenta} toner image is superimposed on the first column. In the third column, only the {cyan} toner image is transferred. When the printing paper 5 is transported by the width of the developing area,
Similarly, the fourth transfer is performed. Even in the fourth transfer, the {cyan, magenta} toner image is transferred in one process, so the {cyan, magenta} toner image is superimposed on the second column. In the fourth row, only the {cyan} toner image is transferred.

Next, as shown in FIG. 14, in the fifth transfer, the toner image of {cyan, magenta, yellow} is transferred in one step, so that the toner image of {cyan, magenta, yellow} is in the first column. In the third column, a {cyan, magenta} toner image is superimposed. In the fifth column, only the {cyan} toner image is transferred. When the printing paper 5 is conveyed by the width of the development area, the sixth transfer is performed in the same manner. Even in the sixth transfer, {Cyan, Magenta, Yellow} is performed in one process.
, The second column overlaps the cyan, magenta and yellow toner images, the fourth column overlaps the cyan and magenta toner images, and the sixth column overlaps the cyan image. Is transferred.

Thereafter, as shown in FIG. 15, in the seventh transfer, the toner image of {cyan, magenta, yellow, black} is transferred in one process, so the first column is {cyan, magenta, yellow, black}. A color toner image is formed by the toner images of
A yellow toner image is superimposed. In the fifth column, the {cyan, magenta} toner image is superimposed, but in the seventh column, only the {cyan} toner image is transferred.

At the end of the transcription, the reverse path is just followed,
In the process, cyan, magenta, yellow, and black toner images were transferred, but cyan was missing, and magenta, yellow, and black were lost. Is only black.

[0014]

However, in the above-described conventional image forming apparatus, as shown in FIGS.
Since the developing means 7C to 7B of each primary color are arranged side by side, 4
The width of the developing means 7C to 7B for each of the primary colors naturally becomes narrower.
The gap 1 is provided to the common developing roller 11 of the developing means 7.
Due to the presence of the portions 3 and 14, the effective use width of the developing roller 11 is further narrowed, causing a problem that the printing speed in color printing is slow. In particular, monochromatic printing such as monochrome printing using black toner is performed. In this case, there is a problem that the printing speed becomes extremely slow as compared with an image forming apparatus that does not use the orthogonal transfer method.

An object of the present invention is to solve the above-mentioned problems and to provide an image forming apparatus in which the printing speed is increased at the time of color printing or monochrome printing such as monochrome printing.

[0016]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention provides a method for transferring a toner image carried on a toner image carrier stretched by a plurality of rollers in a direction perpendicular to a conveying direction of a printing paper. An orthogonal transfer type image forming apparatus in which a toner image transferred to a printing sheet is fixed by transferring the toner image onto the printing sheet in a direction orthogonal to the conveying direction of the printing sheet by an opposing roller, and the toner is attached to a toner image carrier. The developing means for each of the plurality of colors is arranged along the rotation direction of the toner image carrier.

According to the present invention, it is possible to provide an image forming apparatus in which the printing speed in the case of monochromatic printing such as color printing or monochrome printing is increased.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a toner image carried on a toner image carrier stretched by a plurality of rollers in a direction perpendicular to a conveying direction of a printing paper is transferred and opposed. An orthogonal transfer type image forming apparatus in which toner is transferred to a print sheet in a direction perpendicular to a transport direction of the print sheet by a roller and a toner image transferred to the print sheet is fixed, and a plurality of toner images are attached to a toner image carrier. The developing means for each color is arranged along the rotation direction of the toner image carrier, and the entire surface of the developing roller corresponding to each of a plurality of colors can be used effectively, so that color printing or monochrome printing can be performed. This has the effect of increasing the printing speed during monochromatic printing.

According to a second aspect of the present invention, in the first aspect, the plurality of colors of the developing means include three primary colors of cyan, magenta, and yellow. Since the entire surface of the corresponding developing roller can be used effectively, it has an effect of increasing the printing speed in monochromatic printing such as color printing or monochrome printing.

According to a third aspect of the present invention, in the second aspect, the plurality of colors of the developing means include black, and the entire surface of the developing roller corresponding to each of the plurality of colors is formed. Since it can be used effectively, it has the effect of increasing the printing speed in monochromatic printing such as color printing or monochrome printing.

According to a fourth aspect of the present invention, in any one of the second and third aspects of the invention, a plurality of colors of the developing means include light cyan and light magenta. Since the entire surface of the developing roller corresponding to each of a plurality of colors can be effectively used, the printing speed in color printing or monochrome printing such as monochrome printing is increased.

According to a fifth aspect of the present invention, there is provided the invention as set forth in any one of the first, second, third and fourth aspects.
The toner image carrier is formed of a photoreceptor belt, and is provided with an exposing means for exposing the toner image carrier based on an image signal, so that the entire surface of the developing roller corresponding to each of a plurality of colors can be used effectively. Therefore, it has the effect of increasing the printing speed in the case of color printing or monochromatic printing such as monochrome printing.

Hereinafter, embodiments of the present invention will be described, in which the same parts as those of the conventional example are denoted by the same reference numerals.

(Embodiment 1) The outline of one embodiment of the present invention is that a developing means using a whole developing roller for one color is arranged along the rotation direction of the toner image carrier for each color. However, the effective use of the developing roller increases the printing speed in the case of color printing and in the case of monochromatic printing such as monochrome printing. Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is a schematic structural view of an image forming apparatus according to one embodiment of the present invention, FIG. 2 is a perspective view showing a transfer process of the image forming apparatus according to one embodiment of the present invention, and FIG.
FIG. 3 is a schematic diagram illustrating a state of forming a toner layer of a developing roller of the image forming apparatus according to the embodiment of the present invention. And
FIGS. 4 to 7 are schematic views showing a transfer state of the image forming apparatus according to one embodiment of the present invention, and FIG. 8 is a schematic view of a fixing unit of the image forming apparatus according to one embodiment of the present invention. .

In FIG. 1 and FIG. 2, a toner image carrier 1 composed of a photosensitive belt whose surface is coated with a layer of an organic photoconductive material comprises a plurality of support rollers 2, displacement rollers 3, transfer opposing rollers 4, and the like. These rollers are stretched in the direction perpendicular to the direction in which the printing paper 5 is conveyed, and rotate in the direction of the arrow during image formation, so that a primary color toner image is formed on the surface of the toner image carrier 1. Around the toner image carrier 1, a charging unit 6, a cleaning unit 8, and a discharging unit 9 are arranged. Further, around the toner image carrier 1, a developing means 20 which can be separated from and connected to the toner image carrier 1
C, 20M, 20Y, and 20B are arranged along the rotation direction of the toner image carrier 1, and the developing units 20C to 20C for the respective colors are arranged.
In 20B, a developing roller 21 is used exclusively for each color. An exposing unit 10 for irradiating a laser beam is disposed above the toner image carrier 1. In the embodiment of the present invention, a case where a laser is used as a typical example of the exposure unit 10 will be described.
0 may use not only a laser but also an LED or an LCD. As shown by an arrow in FIG. 1, when the toner image carrier 1 rotates in a direction perpendicular to the conveying direction of the printing paper 5, the portion passing through the charging means 6 is uniformly charged to about -600V. The exposing unit 10 irradiates the surface of the toner image carrier 1 with laser light one by one based on the image signals of the four primary colors of cyan, magenta, yellow and black. When the potential of the portion irradiated with the laser beam rises to about −100 V, an electrostatic latent image is formed on the surface of the toner image carrier 10. When only the portion corresponding to the irradiated laser beam of the developing means 20Y to 20B is brought into contact with the portion where the electrostatic latent image is formed, and the toner is pressed by the developing roller 21, the visible image is formed on the toner image carrier 1. , One-color toner images appear one after another.

To briefly explain, as shown in FIGS. 1 and 2, the developing means 20 comprises four developing means 20C-2 for each primary color.
0B, each of which can be separated from and connected to the toner image carrier 1 as described above. However, there is a method such as jumping development performed without contact with the toner image carrier 1. Therefore, in the present invention, the meaning of “contact” that can be separated and contacted includes not only the meaning of “contact” but also the meaning of “approach”. Define.
Developing means 20C is cyan, developing means 20M is magenta,
Four primary color toner layers of cyan, magenta, yellow, and black are formed on the respective developing rollers 21 by the primary color toners contained therein, such that the developing unit 20Y is yellow and the developing unit 20B is black. Then, as shown in FIG. 3, the developing means 20C, 20M, 20Y,
Unlike the conventional example, each developing roller 21 of 20B has a toner layer 12 for one color formed entirely on the developing roller 21.
A gap 22 is provided at the left and right ends of the toner layer 12 and sealed with a sealing material 23.

As is well known, the black color can be generated by using the three primary colors of cyan, magenta and yellow without using black toner.
0 may be constituted by three developing means 20C, 20M and 20Y. Further, in addition to the four primary colors of cyan, magenta, yellow, and black, a developing means of a color such as pale cyan or pale magenta, which is a relatively frequently used color, is added. It is also possible to configure by color.

At the time of transferring the toner image of one color to the printing paper 5, as shown in FIG. 2, the conveyance of the printing paper 5 is temporarily interrupted, and the transfer is performed on the transfer plate 24 (see FIG. 1). The printing paper 5 is stopped and the rotation of the toner image carrier 1 is stopped. Then, the portion where the toner image for one color of the toner image carrier 1 is formed is rubbed against the printing paper 5 by rolling the transfer opposing roller 4 from the back side to transfer the toner image, and the toner image carrier 1 is moved to the left end. Alternatively, it is displaced by one step in the opposite direction from the right end. At this time, the transfer end surface Z of the toner image carrier 1 on which the transfer of the toner image for one color is completed is sequentially separated from the printing paper 5 as the transfer opposing roller 4 passes. During the transfer step, a positive voltage is applied to the transfer plate 24 on which the printing paper 5 is placed, and the negatively charged toner image is drawn from the surface of the toner image carrier 1 to be separated and transferred to the printing paper 5. The transfer by the toner image carrier 1 can be performed not only on the forward path but also on the return path as described above. At this time, when the moving direction of the toner image carrier 1 is viewed from the printing paper 5 side,
The toner image carrier 1 is displaced on the printing paper 5 in a direction perpendicular to the conveying direction of the printing paper 5.

As shown in FIG. 1, the cleaning means 8
Removes the residual toner on the surface of the toner image carrier 1 with a cleaning blade or a cleaning brush, collects the waste toner, and physically cleans the surface of the toner image carrier 1. Then, the charge removing unit 9 neutralizes the negative charge remaining on the surface of the toner image carrier 1 after removing the residual toner, and electrically cleans the surface of the toner image carrier 1. Note that the installation of the charge removing means 9 is not an essential requirement.

When the transfer for one color is completed, the same process is repeated for the remaining colors to finally form a toner image of four primary colors on the printing paper 5 and the transfer for four colors is completed. Each time the printing paper 5 is transported. At this time, the transport distance of the printing paper 5 is only the width of the developing area of each color of the toner image carrier 1 represented by the toner layer of each color shown in FIGS. Since it is used for the development of one color, the width of the development area of each color of the toner image carrier 1 is greatly increased unlike the conventional example. As a result, the transfer speed for one color is increased, and of course, in the case of color printing, in particular, in the case of monochrome printing using black toner or in the case of single color printing with other colors, a large printing compared to the conventional example. There is an increase in speed.

The method of forming a color toner image on the printing paper 5 starts from the state shown in FIG. 4, but the first transfer simply involves transferring the {cyan} toner image. Next, as shown in FIG. 5, in the second transfer, a {magenta} toner image is transferred, and {cyan, magenta}
Are superimposed. Similarly, as shown in FIG. 6, in the third transfer, the {yellow} toner image is transferred, and the {cyan, magenta, yellow} toner images are superimposed. Thereafter, as shown in FIG. 7, in the fourth transfer, a {black} toner image is transferred, and {cyan, magenta, yellow, black} toner images
A color toner image is formed.

After repeating the above steps, the printing paper 5 is gradually fed to the fixing means 17 as shown in FIG.
The fixing means 17 sandwiches the printing paper 5 on which the image has been transferred between the pressing roller 18 and the heating roller 19 having a heat source therein, melts the toner particles, and fixes the toner particles on the printing paper 5. After all the images have been transferred to the printing paper 5,
Since the printing paper 5 is carried out without stopping, the heat source of the heating roller 19 may be kept on. However, printing paper 5
When the image is being transferred to the printing paper 5, the printing paper 5 is in a stopped state, so it is necessary to temporarily turn off the heat source of the heating roller 19 or to move the heating roller 19 away from the printing paper 5. As shown in FIG. 8, a fixing unit 25 composed of a heat source 26 and a reflector 27 is employed, and a reflector 28 is provided below the fixing unit 25 to improve thermal efficiency. There is also a method of fixing without contacting the toner. Thus, a series of image forming steps is completed.

Finally, to briefly describe what is related to the first aspect of the present invention, a photoconductor is not necessarily used as a toner image carrier, and an exposure unit may not be necessary in some cases. That is, a toner image can be formed by forming an electrostatic latent image with a heat source and developing it.
This is because the toner image carrier can be blown off with an air jet after the solid coating with the toner by the developing means, and the toner image can be formed as if engraving a print.

[0035]

As described above, according to the present invention, a toner image carried on a toner image carrier stretched by a plurality of rollers in a direction orthogonal to the transport direction of the printing paper is transferred to the printing paper by a transfer opposing roller. An image forming apparatus of an orthogonal transfer system for transferring a toner image transferred to a printing paper in a direction orthogonal to the conveying direction of the toner and fixing the toner image transferred to the printing paper, the developing of each of a plurality of colors for adhering toner to a toner image carrier. Since the means is arranged along the rotation direction of the toner image carrier, the entire surface of the developing roller corresponding to each primary color can be used effectively, so that printing in color printing or monochromatic printing such as monochrome printing can be performed. Speed can be greatly increased.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a transfer process of the image forming apparatus according to the embodiment of the present invention;

FIG. 3 is a schematic diagram showing a state of forming a toner layer of a developing roller of the image forming apparatus according to the embodiment of the present invention;

FIG. 4 is a schematic diagram showing a transfer state of the image forming apparatus according to the embodiment of the present invention;

FIG. 5 is a schematic diagram showing a transfer state of the image forming apparatus according to the embodiment of the present invention;

FIG. 6 is a schematic diagram showing a transfer state of the image forming apparatus according to the embodiment of the present invention;

FIG. 7 is a schematic diagram showing a transfer state of the image forming apparatus according to the embodiment of the present invention;

FIG. 8 is a schematic diagram of a fixing unit of the image forming apparatus according to the embodiment of the present invention;

FIG. 9 is a schematic configuration diagram of a conventional image forming apparatus.

FIG. 10 is a perspective view showing a transfer process of a conventional image forming apparatus.

FIG. 11 is a schematic view showing a state of forming a toner layer of a developing roller of a conventional image forming apparatus.

FIG. 12 is a schematic diagram illustrating a transfer state of a conventional image forming apparatus.

FIG. 13 is a schematic diagram showing a transfer state of a conventional image forming apparatus.

FIG. 14 is a schematic diagram illustrating a transfer state of a conventional image forming apparatus.

FIG. 15 is a schematic diagram showing a transfer state of a conventional image forming apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 toner image carrier 2 support roller 3 displacement roller 4 transfer opposing roller 5 printing paper 6 charging means 7 developing means 7C developing means 7M developing means 7Y developing means 7B developing means 8 cleaning means 9 discharging means 10 exposure means 11 developing roller 12 toner Layer 13 Gap 14 Gap 15 Seal material 16 Seal material 17 Fixing means 18 Pressure roller 19 Heating roller 20 Developing means 20C Developing means 20M Developing means 20Y Developing means 20B Developing means 21 Developing roller 22 Gap 23 Sealing material 24 Transfer plate 25 Fixing means 26 heat source 27 reflector 28 reflector

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masashi Ogawa 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Shinichi Kizu 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] A transfer roller configured to transfer a toner image carried on a toner image carrier stretched by a plurality of rollers in a direction perpendicular to a transport direction of the print paper in a direction perpendicular to the transport direction of the print paper by a transfer opposing roller; And an image forming apparatus of an orthogonal transfer type for fixing the toner image transferred to the printing paper, the developing means for each of a plurality of colors for attaching toner to the toner image carrier in a rotation direction of the toner image carrier. An image forming apparatus characterized by being arranged along. 2. The image forming apparatus according to claim 1, wherein the plurality of colors of the developing means include three primary colors of cyan, magenta, and yellow. 3. The image forming apparatus according to claim 2, wherein the plurality of colors of the developing means include black. 4. The image forming apparatus according to claim 2, wherein a plurality of colors of the developing means include light cyan and light magenta. 5. A toner image carrier comprising a photoreceptor belt,
5. The image forming apparatus according to claim 1, further comprising an exposure unit configured to expose the toner image carrier based on the image signal.