JPH02211463A - multicolor printing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multicolor printing device, and more particularly to a transfer mechanism for transferring from a photosensitive drum to a sheet of paper.

[Conventional technology]

Conventional technology related to multicolor printing devices is, for example, disclosed in Japanese Patent Application Laid-Open No. 62
-195687 and 61-292167.

When printing in multiple colors on paper, conventionally, as shown in Japanese Patent Application Laid-open No. 62-195687, for example, the paper is wound around a rotating drum called a transfer drum and rotated multiple times. The image formed on the drum is transferred multiple times to obtain prints in multiple colors.

Furthermore, Japanese Patent Laid-Open No. 61-292167 discloses a configuration in which after the first color is transferred and fixed, the paper is conveyed again to the paper feed section, the second color is transferred and fixed, and then the paper is discharged from the apparatus. It is shown.

[Problem to be solved by the invention]

However, in conventional printing devices, the circumference of the transfer drum needs to be longer than the maximum paper size that the device can handle, which results in a large diameter of the transfer drum and the disadvantage of increasing the size of the device. was there. Another problem is that in order to chuck the paper at one location on the transfer drum, paper feeding cannot be started until that location on the transfer drum, that is, the location where the paper is chucked, is in the designated position, and printing takes time. be.

On the other hand, in the conventional method in which transfer and fixing are performed for each color, there is room for improvement in that color misregistration becomes large due to differences in the posture of the paper at the transfer position, as well as expansion and contraction of the paper due to fixing.

The present invention has been made in consideration of the above points, and includes:
The purpose of this is to reduce the height of the printer body compared to conventional printers, reduce printing time, and eliminate paper misalignment at transfer position I when printing in multiple colors. Therefore, printing without color shift can be obtained. An object of the present invention is to provide an improved multicolor printing device.

[Means to solve the problem]

The purpose is a rotating photoreceptor, a 1m charger, and an optical device.

Developing device, transfer belt, cleaning, erasing.

In a multicolor printing device consisting of an electrophotographic system equipped with a fixing device, a paper feeding device, and a drive device that drives the photoconductor and the paper feeding device, when transferring from the photoconductor to paper, When paper is conveyed by a belt and multi-color printing is performed, the transfer belt has a support roller that supports the paper around the bending part of the transfer belt.
This is achieved by attaching a paper presser belt that prevents the paper from peeling off from the roller bending portion and releases the paper restraint after a predetermined number of transfers.

[Effect]

According to the present invention having the above configuration, a flat transfer belt is used instead of a transfer drum with a large diameter when transferring from a photoreceptor to paper, thereby reducing the height of the printer body compared to conventional printers. It can be made smaller, and by using an endless belt as the transfer belt, transfer can be started from any position on the transfer belt, which has the effect of shortening the printing time. Furthermore, when performing multicolor printing, the paper passes through the bend between the drive roller and the driven roller of the transfer belt while being held between the transfer belt and the paper holding belt, so the paper is not positioned correctly at the transfer position. Therefore, printing without color shift can be obtained.

〔Example〕

Hereinafter, the present invention will be explained based on FIGS. 1 to 6. FIG. 1 is a vertical sectional view of a printer portion showing a first embodiment of a multicolor printing device according to the present invention, and FIG. FIG. 3 is a block circuit diagram of the control section indicated by reference numeral 100 in FIG. 1, FIG. 4 is a timing chart for two-color printing, and FIGS. 6 are partial operation explanatory diagrams of the printer shown in the first embodiment.

In FIG. 1, a photosensitive drum 11 is rotatably attached to the center of a printer main body 1. As shown in FIG.

Around the photosensitive drum 11, a charger 21. First developer (
black)22. Second developer (red) 23. Cleaner 24. An erase lamp 25 is provided. A transfer belt 51 is provided below the photosensitive drum 11. The transfer belt 51 is
Drive roller 52. Followed roller 53. It is supported by an adjustment roller 54 and rotates in synchronization with the photosensitive drum 11 . The length of the transfer belt 51 is configured to be longer than the maximum length of paper that can be printed by the printer. Around the transfer belt 51, a transfer belt charger 55. Transfer belt cleaner 56
．． Auxiliary roller (A) 57. An auxiliary roller (I3) 58 is provided. The transfer belt cleaner 56 is configured to move toward and away from the transfer belt 51 as a cam 59 rotates. At both ends of the transfer belt 51, there are pulleys (A) 62. as shown in FIG. Two sets of pulley units 65 consisting of a pulley (I3) 63 and a pulley case 64
65, and between the transfer belt 51 and the pulley unit 65, a paper holding belt (film belt) 60 (+15 m,
The thickness is 0,1 m).

It is configured to sandwich the paper 41.

In FIG. 2, two shafts 66° 66 supporting a pulley unit 65 and a timing belt 67 are provided on the transfer belt 51. The timing belt 67 is supported by two timing pulleys 68, 68, one of which is attached to a step motor 69. 2. The pulley units 65 and 65 are each fixed to a timing belt 67, and the two sets of pulley units 65 and 65 are rotated by the transfer belt 51, respectively, as shown by arrows in FIG. It is configured to move in the width direction. Further, a detection switch 70 for detecting the reference position of the pulley unit 65 is provided near the step motor 69.

In FIG. 1, the lower part of the transfer belt 51 has an LED
II, a light-receiving element 112 is provided, and as described later, only when the paper 41 sandwiched between the transfer belt 51 and the film belt 60 comes above the LED III, the LED II
The structure is such that the light of I reaches the light receiving element 112.

A laser exposure device 31 is provided at the top of the printer main body 1. Inside the laser exposure device '31, there is a semiconductor laser 3.
2 (see Figure 3).

Coupling lens 33 (also see FIG. 3).

Scanner mirror 34. Fθ lens 352 reflection mirror 36
and 37 are provided. In addition, in order to detect the position of the laser beam, a beam detector 38 (see Fig. 3),
A mirror 39 (also see FIG. 3) is provided.

At the bottom of the printer body 1 is a removable paper cassette 42 that stores paper 41. A paper feed roller 43 that feeds the paper 41. A separation belt 44 is provided that separates only one sheet of paper 41 when a plurality of sheets are fed. On the right side of the printer body 1, there is a registration roller 45 that controls the leading edge writing position of the paper 41. A reversing guide 46 is provided to guide the paper 41 to the registration rollers 45. On the left side of the printer main body 1, there is a fixing device 47. A paper guide 48 that guides the paper 41 to the top of the printer body 1. A paper ejection roller 49 is provided, and a paper ejection tray 50 for receiving printed paper 41 is provided at the top of the printer main body 1o. Although not shown in the drawings, the printer main body 1 includes a motor that drives the photosensitive drum and the transfer belt, a motor that drives the developing device, a motor that drives the fixing device and the paper feed roller, and the like. Further, a control section 100 is provided at the bottom of the printer main body 1.

As shown in FIG.
.

ROM102. RAM 103 and further the light receiving element 11
An input boat 104 from various sensors such as 2nd etc., an output boat 105 for controlling ON/OFF of motors, etc., and a laser controller 106. A communication circuit 107 that communicates with the host 140, a clock circuit 108 that serves as a reference for the operation of the CPU10I. It is composed of a step motor controller 109 that controls the rotation of a step motor 69.

A series of programs for controlling the operation of the printer are recorded in the ROM 102, and these programs are divided into two modes: monochrome mode and two-color mode. In addition to the control section 100, the printer main body 1 includes a scanner controller 122 that controls the rotation speed of the scanner mirror 34.
Dedicated circuits such as the following are provided. The output of the light receiving element 112 is set to TTL level by the comparator 113,
This becomes an input signal to the interrupt terminal of CPU10I. host 1
40 is a host CPU 141. Bitmap 142 for storing print information as video data. The printer controller 143 is configured to control the printer.

In FIG. 3, 144 indicates a CRT, and 145 indicates a keyboard.

Next, the operation of the first embodiment will be explained as shown in FIGS.
Referring to the drawings, a description will be given based on FIGS. 4 to 6. As described above, the print command from the host 140 includes a switching signal between the monochrome mode and the two-color mode. Note that the single color mode and the two-color mode differ only in whether or not the step motor 69 rotates, so the two-color mode will be described below.

However, when the printer body 1 is turned on,
The fixing device 48 is stopped except for being controlled to a constant temperature, and is waiting for a print command from the host 140.

The two film belts 60.degree. 60 and the two pulley units 65, 65 are located on both sides of the transfer belt 51, and the detection switch 70 is turned on. When the operator issues a print instruction using the keyboard 145, the host CPυ 141 develops text and graphic data on the bitmap 142, dividing them into black and red. When the expansion is completed, the host CPU 141 issues a print command to the printer 1 via the printer controller 143. The print command includes identification signals for single color mode and two color mode. When receiving a print command from the host 140, R
The old 02 program distinguishes between single color mode and two color mode.

With BusyN low, each motor and scanner mirror 3
4 starts rotating, a high voltage is applied to the charger 21, and the photosensitive drum 11 is uniformly charged. Further, a high voltage is applied to the transfer belt charger 55, and the transfer belt 51 is uniformly charged. Furthermore, one sheet of paper 41 is removed from the paper cassette 42.
The sheet is pulled out by the paper feed roller 43 and sent to the registration rollers 45. After a certain period of time (T1), cputo
i transmits a vertical synchronization signal via the 1 communication circuit 107.

The host 140 that has received the vertical synchronization signal transmits black print data to the printer 1 using the signal from the beam detector 38 as a horizontal synchronization signal. The print data is sent via the laser controller 106 to the ON/OFF state of the semiconductor laser 32.
Controls FF. The laser beam oscillated from the semiconductor laser 32 becomes a parallel beam by the coupling lens 33, is scanned by the scanner mirror 34, passes through the Fθ lens 35, the reflecting mirrors 36 and 37, and then reaches the photosensitive drum 11.
An electrostatic latent image is formed on the photosensitive drum 11 by focusing on the photosensitive drum 11. The electrostatic latent image on the photosensitive drum 11 is transferred to the first developing device (black).
22, a black fine powder is attached and developed. On the other hand, the registration roller 45 operates for a certain period of time (T) from the start of printing.
2) After that, it starts rotating and sends out the paper 41 that was stopped before the registration roller 45. The paper 41 is attracted toward the transfer belt 51 which is charged to a high voltage. Photosensitive drum 1
The black fine powder on 1 is transferred to the transfer belt 5 charged with a high voltage.
1, the image is transferred onto the paper 41.

A cleaner 24 removes the black fine powder remaining on the photosensitive drum 11 without being transferred, and an erase lamp 25 removes the electric charge remaining on the photosensitive drum 11. Photosensitive drum 1
1 is then uniformly charged again by the charger 21 and is reused.

The step motor 69 moves the tip of the paper 41 to the photosensitive drum 1.
It starts rotating when it passes under 1, and pulley unit 6
5 to a predetermined position (the moving distance of the pulley unit 65 varies depending on the paper size), the film belt 60 changes its position as the pulley unit 65 moves, until the leading edge of the paper 41 When the paper 41 comes under the pulley unit 65, both ends of the paper 41 are sandwiched between the film belt 60 and the transfer belt 51 (time A, see FIG. 5), and the film belt 60 is sequentially moved.

Move to both ends of the paper 41 and spread the paper 4 along its entire length.
1, and the paper 41 goes around the lower part of the transfer belt 51 along the transfer belt 51. At this time,
The cam 59 rotates to separate the transfer belt cleaner 56 from the transfer belt 51. As the transfer belt 51 rotates, the leading edge of the paper 41 comes to the top of the LED III, and the light receiving element 11
2 receives the LHDIII light, the output of the light-receiving element 112 changes, the output of the comparator 113 becomes low level, and an interrupt is applied to cputoi. After a certain period of time (T3) after the interrupt, the CPt 1101 transmits a vertical synchronization signal via the 1 communication circuit 107. Note that since the circumferential length of the transfer belt 51 is longer than the length of the paper 41, the vertical synchronization signal is transmitted after the black electrostatic latent image is formed.

Then, the host l-140 that has received the vertical synchronization signal transmits red print data to the printer 1 using the signal from the beam detector 38 as a horizontal synchronization signal. The print data is sent to the semiconductor laser 32 via the laser controller 106.
ON.

OFF is controlled to form a latent image of WPL on the photosensitive drum 11. The electrostatic latent image on the photosensitive drum 11 is transferred to the second developing device (
red) 23, red fine powder is attached and developed.

While the paper 41 passes through the transfer belt charger 55.

Although the application of high voltage to the transfer belt charger 55 is stopped, the charges on the transfer belt 51 are not discharged, so that the red fine powder on the photosensitive drum 11 can be transferred onto the paper 41. When the leading edge of the paper 41 passes under the photosensitive drum 11, the step motor 69 starts rotating in the opposite direction, and moves the pulley unit 65 to the end of the transfer belt 51. The film belt 60 changes its position as the pulley unit 65 moves.

Move away from both ends of the paper 41 and release the leading edge of the paper 41 (time B, see FIG. 6). Paper 41 is.

Due to the rigidity of the paper itself, it cannot keep up with the curvature of the drive roller 52 and moves away from the transfer belt 51.

The film belt 6o gradually moves away from the paper 41 and releases the paper 41.

The paper 41 to which the black and red fine powders have been transferred is transferred to the fixing device 4.
7, the fixing device 47 melts the fine powder with heat and pressure and fixes it on the paper 41. Thereafter, the paper 41 is moved to the paper guide 48. The paper passes through the paper ejection roller 49 and is ejected onto the paper ejection tray 5o.

The BuByN signal becomes high during writing of red data, and the printer waits for a command to print the next page. If there are multiple pages to print, the host 140 immediately prints the black data of the next page into the bitmap 14 after sending the black data.
After the transmission of the red data is completed, the red data is expanded on the bitmap 142. After the expansion is completed, a print command is sent.

If there is no print command before the printed paper 41 is ejected, the CPυ 101 stops each motor and the like.

In FIG. 4, the dotted line is a timing chart when printing multiple copies of the same page (data development is not required from the second page onwards).

If the print command specifies monochrome mode, the first developer (
black)22. Alternatively, the second developing device (red) 23 operates.

Further, the step motor 69 does not operate, and the paper 41 heads toward the fixing device 47 without being wound around the transfer belt 51.

When a print command for the next page is received, each motor etc. starts rotating again and the above operations are repeated.

Note that by setting the amount of development to 3 or 4, a riffle color can be achieved.

In the embodiment described above, it is not possible to form an image on the portion sandwiched by the film belt 60, but since the thickness of the film belt 60 is as thin as 0.1 m, there may be transfer defects or the like on other portions of the paper 41. No printing defects occur. According to the prototype experiment, the thickness of the film belt 60 is as follows:
Even if the thickness was about 0.2 mm, no printing defects such as transfer defects were observed on other parts of the paper 41.

The present invention is as described above, and as is clear from the description of the embodiments described above, according to the present invention, when transferring from the photosensitive drum 11 to the paper 41, a fan-flat transfer drum is used instead of a large-diameter transfer drum. By using the transfer belt 51, the height of the printer main body 1 can be made smaller than in the past, and by using an endless belt for the transfer belt 51, transfer can be started from any position on the transfer belt 51. This has the effect of shortening the printing time. Furthermore, when printing in multiple colors.

The sheet of paper 41 is held between the transfer belt 51 and the film belt 60, and the drive roller 5 of the transfer belt 51
2 and the driven roller 53, there is no misalignment of the paper 41 at the transfer position, and therefore printing without color misregistration can be achieved.

FIG. 7 shows a transfer belt 5 showing a second embodiment of the apparatus of the present invention.
1 and a schematic diagram of related parts.

In this embodiment, a transfer belt charger 55 is provided inside the transfer belt 51 and facing the photosensitive drum 11 . Furthermore, in terms of timing, the configuration is such that a high voltage is applied to the transfer belt charger 55 only when transferring fine powder to paper.

According to this embodiment, since the influence of self-discharge of the transfer belt 51 can be eliminated, there is an effect that the transfer efficiency of the second color can be increased.

FIG. 8 shows a transfer belt 5 showing a third embodiment of the apparatus of the present invention.
1 and a schematic diagram of related parts, FIGS. 9 and 10 are all explanatory views of the operation of the third embodiment of the present invention shown in FIG. 3.

In this embodiment, two sets of film belt units (A) 72.
A film belt unit (B) 73 is provided. The film belt unit (A) 72 includes the film belt 60
It is composed of a pulley (A) 62 and a pulley (B) 63. The film belt unit (B) 73 includes a film belt 61, a pulley (A) 62, and a pulley (B).
63.

Film belt unit (A) 72. The film belt unit (B) 73 includes a timing belt and a step motor, respectively, as in the first embodiment.
It is configured to move in the width direction.

Next, the operation of the third embodiment will be described, but since the timing of the vertical synchronization signal and the like is the same as that of the first embodiment described above, the explanation will be omitted.

Therefore, when the power is on, the film belt unit (A) 72. Both film belt units (B) 73 are located at reference positions at both ends of the transfer belt 51. When printing starts and the first color is transferred to the paper 41, the film belt unit (A) 72 moves in the width direction of the paper 41 (see FIG. 9), and the paper 41 is moved between the film belt 60 and the transfer belt. At the time when the trailing edge of the paper 41 is transferred, the film belt unit (B) 73 transfers the paper 41 to the lower side of the transfer belt 51.
Move in the width direction. Paper 41 is.

It is again sandwiched between the film belt 61 and the transfer belt 51, goes around the upper side of the transfer belt 51, and the second color is transferred. At this time, the film belt unit (A) 72 moves to the reference position (see FIG. 10), and the paper 41 cannot keep up with the curvature of the drive roller 52 due to the rigidity of the paper itself, and moves away from the transfer belt 51. After the second color transfer is completed, the film belt unit (B) 73 moves to the reference position.

According to this embodiment, since there is no film belt 60 between the paper 41 and the photosensitive drum 11 during transfer, there is an effect that the printing width can be widened.

FIG. 11 is a schematic diagram of a transfer belt 51 and related parts showing a fourth embodiment of the apparatus of the present invention, and FIG. 12 is an explanatory diagram of the operation of the fourth embodiment of the present invention shown in FIG. 11.

In this embodiment, in addition to the third embodiment, a nine paper peeling plate 75 is added located on the transfer belt 51, and the paper peeling plate 75 is operated by a solenoid (not shown).
It is configured to be able to approach and separate from the transfer belt 51.

Next, the operation of the fourth embodiment will be described, and the timing of the vertical synchronization signal and the like is the same as in the first embodiment described above.

Therefore, when the power is on, the film belt unit (A) 72. Both film belt units (B) 73 are located at reference positions at both ends of the transfer belt 51. When printing starts, film belt unit (A) 7
2. Both film belt units (B) 73 move in the width direction of the paper 41. When the first color is transferred onto the paper 41, the paper separation plate 75 is attracted by the solenoid and separated from the transfer belt 51. The paper 41 passes under the paper peeling plate 75, is sandwiched between the film belt 60 and the transfer belt 51, and goes under the transfer belt 51. The paper 41 is again separated from the film belt 61 and transfer belt 51. The second color is transferred onto the upper side of the transfer belt 51, and the second color is transferred. At this time, the solenoid is released and the paper release plate 7
5 contacts the transfer belt 51. The paper 41 is peeled off from the transfer belt 51 by the paper peeling plate 75 and headed for the fixing device (see FIG. 12), where it is transferred to the film belt unit (A
)72. After the printing is completed, the film belt unit (B) 73 moves to the reference position.

According to this embodiment, the film belt unit (
A)72. Since there is no need to reciprocate the film belt unit (B) 73 between the width position of the paper 41 and the reference position, the length of the transfer belt 51 corresponding to the reciprocating time can be shortened, and the length of the printer 1 body can be reduced. It has the effect of being able to reduce the size and further reducing the power consumption associated with movement.

FIG. 13 shows a transfer belt 51 showing a fifth embodiment of the present invention.
FIG. 14 is an explanatory diagram of the operation of the fifth embodiment of the present invention shown in FIG. 13.

In this embodiment, as in the fourth embodiment, the paper release plate 75
At the same time, film belt unit 7 is added.
2 covers the lower part of the transfer belt 51. That is, the paper is also configured to be held between the transfer belt 51 and the film belt 61 on the lower side of the transfer belt 51 straddling the drive roller 52 and the driven roller 53, and the paper peeling plate 75 is Similar to the fourth embodiment, the transfer belt 51 is configured to be able to approach and separate from the transfer belt 51 using a solenoid (not shown). Further, the transfer belt charger 55 is located inside the transfer belt 51 and faces the photosensitive drum 11, as in the second embodiment (FIG. 7).

Next, the operation of the fifth embodiment will be explained. The timing of the vertical synchronization signal etc. is also the same as in the first embodiment described above, and only when transferring the fine powder to the paper.
A high voltage is applied to the transfer belt charger 55.

Thus, when the power is on, the film belt unit 72 is located at the reference position at both ends of the transfer belt 51. When printing starts, the film belt unit 72
moves in the width direction of the paper 41. When the first color is transferred onto the paper 41, the paper separation plate 75 is attracted by the solenoid and separated from the transfer belt 51. The paper 41 passes under the paper peeling plate 75 and passes through the film belt 60 and the transfer belt 51.
The transfer belt 51 is sandwiched between the transfer belts 51 and 51, and goes under the transfer belt 51.

The paper 41 passes under the transfer belt 51 as it is, and then goes around the top of the transfer belt 51 again. When the second color is transferred, the solenoid is released and the paper peeling plate 75 moves away from the transfer belt 51. to be fused to. The paper 41 is peeled off from the transfer belt 51 by a paper peeling plate 75 and headed for the fixing device (see FIG. 14), where it is transferred to the film belt unit 7.
2 is.

After printing is completed, move to the reference position.

According to this embodiment, the paper 41 can also be placed under the transfer belt 51.
Since the paper is sandwiched between the two, the paper is transported stably. Also,
Similar to the second embodiment shown in FIG. 7, since the influence of self-discharge of the transfer belt 51 can be eliminated, there is an effect that the transfer efficiency of the second color can be increased.

〔Effect of the invention〕

The present invention is as described above, and as is clear from the description of the illustrated embodiments, according to the present invention, a flat transfer belt is used instead of a large diameter transfer drum when transferring from a photoreceptor to paper. By using this, the height of the printer body can be reduced compared to conventional printers, and by using an endless transfer belt, transfer can be started from any position on the transfer belt, reducing printing time. The effect is that it can be done. Furthermore, when performing multicolor printing, the paper passes through the bend between the drive roller and the driven roller of the transfer belt while being held between the transfer belt and the paper holding belt, so the paper is not positioned correctly at the transfer position. Therefore, it is possible to achieve the effect that printing without color shift can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a printer portion showing a first embodiment of a multicolor printing device according to the present invention, FIG. 2 is a perspective view of main parts of the first embodiment, and FIG. 4 is a timing chart for two-color printing, and FIGS. 5 and 6 are partial operation explanatory diagrams of the printer shown in the first embodiment. , FIG. 7 is a schematic diagram of a transfer belt 51 and related parts showing a second embodiment of the apparatus of the present invention, and FIG. 8 is a schematic diagram of a transfer belt 51 and related parts showing a third embodiment of the apparatus of the present invention. , FIG. 9 and 1
0 is an operational explanatory diagram of the third embodiment of the present invention shown in FIG. 3, FIG. 11 is a schematic diagram of the transfer belt 51 and related parts showing the fourth embodiment of the apparatus of the present invention, FIG. 12 is an explanatory diagram of the operation of the fourth embodiment of the present invention shown in FIG. 11.
, FIG. 13 shows a transfer belt 5 showing a fifth embodiment of the present invention.
1 and a schematic diagram of related parts, and FIG. 14 is an operation explanatory diagram showing the fifth embodiment of the present invention shown in FIG. 13. 1...Printer main body, 11...Photosensitive drum, 21.
... Charger, 22... First developer (black), 23...
2nd developer (red), 24... cleaner, 25... erase lamp, 31... laser exposure device, 41...
Paper, 47... Fixing device, 51... Transfer belt, 52
... Drive roller, 53 ... Followed roller, 55 ...
Transfer belt charger, 60...Paper presser belt (film belt), 61...Paper presser belt (film belt). Diagram $q Hard first opening i f4t, Tar first first round hair I

Claims (1)

[Scope of Claims] 1. An electrophotographic system including a rotating photoreceptor, a charging device, an exposure device, a developing device, a transfer belt, a cleaning, an eraser, and a fixing device, a paper feeding device, and the photoreceptor and paper feeding device. In a multicolor printing device consisting of a drive device that drives the device, when transferring from the photoreceptor to paper, the paper is conveyed by a belt, and when multicolor printing is performed, the transfer belt has a , a paper presser that supports the paper around the bending part of the transfer belt supporting roller and prevents the paper from peeling off from the bending part of the roller, and releases the previous paper restraint after a predetermined number of transfers is completed. A multicolor printing device characterized by an attached belt. 2. An electrophotographic system including a rotating photoconductor, a charger, an exposure device, a developing device, a transfer belt, a cleaning, an eraser, and a fixing device, a paper feeding device, and a drive for driving the photoconductor and the paper feeding device. In a multicolor printing device consisting of a device, when transferring from the photoreceptor to paper, the paper is conveyed by a belt, and when multicolor printing is performed, a transfer belt is attached to the side of the transfer belt. A paper holding belt is attached to support the paper around the supporting roller bending part and prevent the paper from peeling off from the roller bending part, and to release the paper restraint after a predetermined number of transfers. A multi-color printing device characterized in that the paper presser belt is configured to reciprocate in the width direction of the transfer belt. 3. In the invention as set forth in claim 2, a multi-color paper presser belt is provided on both sides of the transfer belt, and each paper presser belt is configured to reciprocate in the width direction of the transfer belt. Printing device. 4. An electrophotographic system including a rotating photoconductor, a charger, an exposure device, a developing device, a transfer belt, a cleaning, an eraser, and a fixing device, a paper feeding device, and a drive for driving the photoconductor and the paper feeding device. In a multicolor printing device, when transferring from the photoreceptor to paper, the paper is conveyed by a belt, and when multicolor printing is performed, the drive roller side and the driven roller side of the transfer belt. In order to do this, it supports the paper around the bending part of the transfer belt supporting roller and prevents the paper from peeling off from the bending part of the roller, and at the same time, after a predetermined number of transfers is completed, the previous paper restraint is released. Two sets of paper presser belt units are attached to
A multicolor printing device characterized in that each paper presser belt in the two sets of paper presser belt units is configured to reciprocate in the width direction of the transfer belt. 5. In the invention described in claim 4, two sets of paper presser belt units are attached, located on the drive roller side and the driven roller side of the transfer belt, and the two sets of paper presser belt units are attached. A multicolor printing device in which paper presser belts located inside the transfer belt and provided on both sides of the transfer belt are configured to reciprocate in the width direction of the transfer belt. 6. In the invention according to any one of claims 1 to 5, a charger for the transfer belt is provided inside the transfer belt and facing the photoreceptor, and the fine powder is transferred to the paper. A multicolor printing device configured to apply a high voltage to the transfer belt only when the transfer belt is used. 7. In the invention according to any one of claims 1 to 6, a paper release plate is located between the photoreceptor and the fixing device, and is located above the transfer belt, with respect to the transfer belt. A multi-color printing device that can be moved closer and further away. 8. In the invention according to any one of claims 1 to 3 or 6 to 7, on the lower side of the transfer belt straddling the transfer belt drive roller and the driven roller. This is a multicolor printing device configured to hold paper between a transfer belt and a paper presser belt.