JP2018108644A - Image formation apparatus and image formation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means of preventing the disturbance of an image at the cutting of the continuous sheet and securing the stability of conveyance of a continuous sheet.SOLUTION: An image formation apparatus includes: a conveyance unit which conveys a continuous sheet; a cutting unit which is arranged on the conveyance unit and cuts the conveyed continuous sheet; an image formation unit which is arranged on the downstream side of the cutting unit of the conveyance unit in the conveyance direction of the continuous sheet and forms the image of the conveyed continuous sheet; and a slack generation unit 17 which generates the slack of the continuous sheet conveyed between the cutting unit and the transfer unit. The slack generation unit generates the slack on the continuous sheet when the conveyance amount of the continuous sheet becomes the prescribed amount of the conveyance amount before the continuous sheet is cut by the cutting unit.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus and an image forming method for cutting continuous paper while forming an image on continuous paper.

  The conventional image forming apparatus forms a slack in the continuous paper to prevent image distortion when cutting the continuous paper, and secures a desired slack in the continuous paper to ensure good conveyance of the continuous paper. However, continuous paper is conveyed while gradually reducing the slackness (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 8-091651

However, in the conventional technology, since continuous paper is always conveyed while maintaining a desired slack, there is a problem that the stability of conveying the continuous paper cannot be ensured.
An object of the present invention is to solve such a problem, and an object of the present invention is to prevent image disturbance when cutting continuous paper and to ensure the stability of conveyance of the continuous paper.

  Therefore, the present invention provides a conveyance unit that conveys continuous paper, a cutting unit that is disposed in the conveyance unit and cuts the continuous paper being conveyed, and downstream of the cutting unit of the conveyance unit in the conveyance direction of the continuous paper. And an image forming unit that forms an image on the continuous paper that is being transported, and a slack generating unit that generates slack in the continuous paper that is transported between the cutting unit and the transfer unit. The slack generating unit generates slack in the continuous paper before the continuous paper is cut by the cutting unit and when the amount of continuous paper transport reaches a predetermined amount.

  According to the present invention as described above, it is possible to prevent the image from being disturbed at the time of cutting the continuous paper and to secure the stability of the continuous paper conveyance.

Schematic side sectional view showing a configuration of a printing apparatus in an embodiment The block diagram which shows the control structure of the printing apparatus in an Example Explanatory drawing of cutting operation and image forming operation of continuous paper in the embodiment Explanatory drawing of cutting operation and image forming operation of continuous paper in the embodiment Explanatory drawing of cutting operation and image forming operation of continuous paper in the embodiment Explanatory drawing of control of the motor A in an Example Schematic side sectional view showing a configuration of a printing apparatus in a comparative example Explanatory drawing of the slack creation operation in the comparative example Illustration of shock line generation in a comparative example

  Hereinafter, embodiments of an image forming apparatus and an image forming method according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional side view illustrating a configuration of a printing apparatus according to an embodiment.
In FIG. 1, a printing apparatus 1 as an image forming apparatus is an electrophotographic printer that cuts and discharges a roll paper P at an arbitrary length while forming an image on a roll paper P as a continuous paper.
The printing apparatus 1 includes a transfer belt 2, a transfer roller 3, a fixing unit 4, a rotary cutter 5, a transport roller A6, a transport roller B7, a transport roller C8, a transport roller D9, a motor A10, and a motor. B 11, a slack area 13, an image unit (hereinafter referred to as “ID unit”) 15 K, 15 C, 15 Y, 15 M, 15 W, and a sensor 16.

  The transport roller A6 is a pair of rollers that sandwich and transport the roll paper P by rotating. The conveyance roller A6, together with the conveyance roller B7, the conveyance roller C8, and the conveyance roller D9, forms a conveyance unit as a conveyance unit that conveys the roll paper P in the medium conveyance direction indicated by an arrow A in the drawing. A transport roller A6 is disposed at the uppermost stream in the medium transport direction of the transport unit.

The transport roller B7 is a roller pair that is disposed downstream of the rotary cutter 5 in the medium transport direction and that sandwiches and transports the roll paper P by rotating.
The transport roller C8 is a roller pair that is disposed downstream of the transport roller B7 in the medium transport direction, and sandwiches and transports the roll paper P by rotating.
The transport roller D9 is a roller pair that is disposed downstream of the transport roller C8 in the medium transport direction and that sandwiches and transports the roll paper P by rotating.

The transfer belt 2 is rotatably stretched by a plurality of rollers such as a belt roller, and conveys a toner image as a developer image formed by the ID units 15K, 15C, 15Y, 15M, and 15W to the transfer roller 3. It is.
Each of the ID units 15K, 15C, 15Y, 15M, and 15W includes a photosensitive drum that is a plurality of image carriers that are rotatably provided, and includes black (K), cyan (C), yellow (Y), An image forming operation is performed in which magenta (M) and white (W) toner images are formed on a photosensitive drum, and are primarily transferred onto the oppositely disposed transport belt 2.

  The transfer roller 3 serving as an image forming unit and a transfer unit is disposed downstream of the conveyance roller D9 (rotary cutter 5) of the conveyance unit in the medium conveyance direction indicated by an arrow A in the drawing, and is transferred to the roll paper P being conveyed. The toner image formed on 2 is transferred to form an image. The transfer roller 3 transfers the toner image formed on the transfer belt 2 to the roll paper P by applying a high voltage. The image formed by the image forming unit is not limited to the toner image, and may be an image such as ink.

The fixing unit 4 is disposed downstream of the transfer roller 3 in the medium conveyance direction, conveys the roll paper P, and fixes the toner image transferred to the roll paper P. The fixing unit 4 includes a fixing roller having a heating member, and fixes the toner image transferred to the roll paper P with heat and pressure. The roll paper P on which the toner image is fixed is conveyed outside the apparatus by the conveyance roller 4a.
In this way, the conveyance roller A6, the conveyance roller B7, the conveyance roller C8, the conveyance roller D9, and the conveyance roller 4a of the fixing unit 4 form a conveyance path through which the roll paper P is conveyed.

  The rotary cutter 5 serving as a cutting unit is disposed in the transport unit, is disposed downstream of the transport roller A6 in the medium transport direction, and cuts the roll paper P transported by the transport roller A6, the transport roller B7, and the like. . The rotary cutter 5 is capable of cutting the roll paper P being conveyed in a direction substantially perpendicular to the medium conveyance direction by rotating the rotary blade. For example, the rotary cutter 5 includes a stationary blade that does not rotate and a rotating blade that rotates at a speed equal to or higher than the transport speed of the roll paper P1 by the transport roller A6, the transport roller B7, and the like.

The motor A10 is a drive source that rotationally drives the transport roller A6 and the transport roller B7.
The motor B11 is a drive source that rotationally drives the transport roller C8 and the transport roller D9.
The motor A10 and the motor B11 are individually controlled in rotation speed, rotation amount, and the like by the control unit. Therefore, slack can be formed in the roll paper P to be conveyed by making the rotation speed of the conveyance roller A6 and the conveyance roller B7 faster than the rotation speed of the conveyance roller C8 and the conveyance roller D9.

The motor A10 and the motor B11 are configured by, for example, stepping motors, and operate according to pulses output from the control unit. The rotation speed is controlled by the frequency of the output pulses, and the rotation amount is controlled by the number of output pulses.
The sensor 16 serving as a detection unit is disposed downstream of the transport roller A6 in the medium transport direction and upstream of the rotary cutter 5, and detects the leading edge of the roll paper P.

  The slack area 13 is an area surrounded by the paper guide 13a and the paper guide 13b disposed between the transport roller B7 and the transport roller C8. The paper guide 13a is disposed above the medium conveyance path, and the paper guide 13b is disposed below the medium conveyance path, and is fixed to the main body frame of the apparatus. The slack area 13 holds a space in which a slack of the roll paper P conveyed by the conveyance roller B7 and the conveyance roller C8 is formed.

In the slack area 13, a sensor for detecting slack of the roll paper P is not provided, and the paper guide 13a and the paper guide 13b are not opened and closed.
In this embodiment, the transport roller A6 and the transport roller B7, the motor A10 that rotates the transport roller A6 and the transport roller B7, the transport roller C8 and the transport roller D9, and the motor B11 that rotates the transport roller C8 and the transport roller D9, The slack generation unit 17 is configured by the slack area 13 including the paper guide 13a and the paper guide 13b.

The slack generation unit 17 generates slack in the roll paper P before the roll paper P is cut by the rotary cutter 5 and when the transport amount of the roll paper P reaches a predetermined amount.
Further, the slack generation unit 17 is disposed downstream of the conveyance roller A6 and the conveyance roller B7 in the conveyance direction of the roll paper P as the conveyance roller A6 and the conveyance roller B7 as the first conveyance unit that conveys the roll paper P, Conveyance roller C8 and conveyance roller D9 which convey roll paper P are formed, and the conveyance speed of conveyance roller A6 and conveyance roller B7 is made faster than the conveyance speed of conveyance roller C8 and conveyance roller D9, and slack is formed in roll paper P To do.

FIG. 2 is a block diagram illustrating a control configuration of the printing apparatus according to the embodiment.
In FIG. 2, the printing apparatus 1 includes a storage unit 21 and a control unit 22.
The storage unit 21 includes a memory and the like, and a control program for controlling information on the number of pulses output to the motor A10 and the motor B11 as information indicating the cutting position and the slack generation position of the roll paper P and the operation of the entire printing apparatus 1. (Software) etc. are memorized.

  The control unit 22 is connected to the sensor 16, the motor A10, the motor B11, and the storage unit 21, and includes control means such as a CPU (Central Processing Unit). The control unit 22 is externally based on a control program (software) stored in the storage unit 21. The overall operation of the printing apparatus 1 including the communication of the apparatus is controlled.

  Further, when the sensor 16 detects the leading edge of the roll paper P with the sensor 16, the control unit 22 controls the transport amount of the roll paper P based on that. Therefore, the control unit 22 determines the cutting position and the slack generation position of the roll paper P based on the rotation amounts of the motor A10 and the motor B11 after the sensor 16 detects the leading edge of the roll paper P. Note that the information indicating the cutting position and the slack generation position of the roll paper P is stored in advance in the storage unit 21 as the number of pulses output to the motor A10 and the motor B11.

  The slack generation unit 17 shown in FIG. 1 is controlled by the control unit 22 so that the transport amount of the roll paper P calculated by the control unit 22 based on the leading edge of the continuous paper detected by the sensor 16 becomes a predetermined amount. When the sheet reaches the slack generation position, the transport speed of the transport roller A6 and the transport roller B7 by the motor A10 is changed so as to be faster than the transport speed of the transport roller C8 and the transport roller D9 by the motor B11, and the roll paper P is slackened. Form.

The operation of the above configuration will be described.
First, the image forming operation of the printing apparatus when the roll paper is cut by the rotary cutter in a state where the leading edge of the roll paper does not reach the transfer roller is an explanatory diagram of the continuous paper cutting operation and the image forming operation in the embodiment of FIG. This will be described with reference to FIG.
When the operator holds the leading end of the roll paper P1 between the conveying roller A6 of the printing apparatus 1 and the control unit 22 of the printing apparatus 1 receives print data from the external apparatus, the printing apparatus 1 rotates the motor A10 and the motor B11. And the conveyance of the roll paper P1 is started.

The leading edge of the roll paper P1 passes through the rotary cutter 5 and the transport roller B7 and is transported by being sandwiched between transport rollers C8 rotated by a motor B11 rotating at the same speed as the motor A10.
When the leading end of the roll paper P1 is sandwiched between the transport rollers 8C and the transport amount of the roll paper P1 by the motor A10 and the motor B11 reaches a predetermined transport amount, the printing apparatus 1 Driving is started and the roll paper P1 is cut. In this way, the printing apparatus 1 cuts the roll paper P1 by a predetermined length.

At this time, the leading edge of the roll paper P <b> 1 does not reach between the transfer roller 3 and the transfer belt 2. Therefore, no slack is generated in the roll paper P1.
When the roll paper P1 is cut by the rotary cutter 5, the roll paper P1 generates the rear end of the roll paper P1 and the front end of the roll paper P1 of the next page at the position indicated by the arrow B in the drawing.

The rotary cutter 5 is connected to a cutter motor, and the cutter motor is driven under the control of the control unit 22 to cut the roll paper P1. Further, the rotary cutter 5 is driven at a speed higher than the transport speed of the roll paper P1. Thereby, the roll paper P1 can be cut without stopping the conveyance of the roll paper P1.
Here, the influence on the roll paper P1 generated when the roll paper P1 is cut by the rotary cutter 5 will be described.

First, the influence on the roll paper P1 when the leading edge of the roll paper P1 reaches between the transfer roller 3 and the transfer belt 2 will be described.
The conveyance speed of the roll paper P1 by the conveyance roller A6 and the conveyance roller B7 by the motor A10 and the conveyance roller C8 and the conveyance roller D9 by the motor B11 are set to the same speed, and the roll paper P1 is rotated in a state where the roll paper P1 is not slackened. When the cutter 5 cuts, the impact of the rotary cutter 5 is transmitted to the roll paper P1, propagates to the transfer portion which is the contact portion between the transfer roller 3 and the transfer belt 2, and is transferred from the transfer belt 2 to the roll paper P1. The image will be disturbed. The disturbance of the transfer image that occurs when the roll paper P1 is cut by the rotary cutter 5 is referred to as a “shock line”.

The rotary cutter 5 cuts the roll paper P1 with a rotating blade that rotates at a speed equal to or higher than the conveying speed of the roll paper P1 and a fixed blade that does not rotate in order to cut the roll paper P1 while transporting it.
However, when the leading edge of the roll paper P1 reaches between the transfer roller 3 and the transfer belt 2, a shock line is generated in the roll paper P1 due to propagation of the impact when cutting the roll paper P1 to the transfer portion. Resulting in.

Next, the influence on the roll paper P1 when the leading edge of the roll paper P1 does not reach between the transfer roller 3 and the transfer belt 2 will be described.
When the leading edge of the roll paper P1 does not reach the space between the transfer roller 3 and the transfer belt 2, the shock when the roll paper P1 is cut does not propagate to the transfer portion, and therefore the shock line is applied to the roll paper P1. Will not occur.

Therefore, in this example in which the roll paper P1 is cut by the rotary cutter 5 in a state where the leading edge of the roll paper P1 does not reach the transfer roller 3, the leading edge of the roll paper P1 is between the transport roller D9 and the transfer roller 3. No shock line is generated on the roll paper P1.
On the roll paper P1 cut by the rotary cutter 5, the toner image formed on the transfer belt 2 is transferred at the transfer portion between the transfer roller 3 and the transfer belt 2, and the toner image is fixed at the fixing portion 4, and the apparatus is fixed. Then, the image forming operation is finished.

  Next, the image forming operation of the printing apparatus when the roll paper is cut with the rotary cutter while the leading edge of the roll paper has reached the transfer roller is the continuous paper cutting operation and the image in the embodiment shown in FIGS. Based on the explanatory view of the forming operation, it will be described with reference to the explanatory view of the control of the motor A in the embodiment of FIG. 2 and FIG. In FIG. 6, the horizontal axis represents the passage of time, the vertical axis represents the rotational speed, and L represents the transport amount of the roll paper.

When the operator holds the leading end of the roll paper P1 between the conveying roller A6 of the printing apparatus 1 and the control unit 22 of the printing apparatus 1 receives print data from the external apparatus, the printing apparatus 1 rotates the motor A10 and the motor B11. And the conveyance of the roll paper P1 is started.
The leading edge of the roll paper P1 passes through the rotary cutter 5 and the transport roller B7 and is transported by being sandwiched between transport rollers C8 rotated by a motor B11 rotating at the same speed as the motor A10.

The printing apparatus 1 nips and conveys the leading edge of the roll paper P1 with the conveyance roller 8C, and further nips it with the conveyance roller D9 and conveys it to the transfer portion that is a contact portion between the transfer belt 2 and the transfer roller 3.
The printing apparatus 1 that has transported the roll paper P1 to the transfer unit transfers the toner image formed on the transfer belt 2 to the roll paper P1 at the transfer unit between the transfer roller 3 and the transfer belt 2, and the fixing unit 4 performs toner transfer. Fix the image.

  After the leading edge of the roll paper P1 has passed the fixing unit 4, the slack generation unit 17 of the printing apparatus 1 has a predetermined transport amount X1 in which the transport amount of the roll paper P1 by the motor A10 is already set, that is, the roll paper P1 is When the slack generation position is reached, the transport speed of the motor A10 driven at the same transport speed V1 as the transport speed V1 by the motor B11 is changed to a transport speed V2 higher than the transport speed V1, as shown in FIG.

By changing the transport speed of the motor A10 to a transport speed V2 that is faster than the transport speed V1, a slack 14 is generated on the roll paper P1 in the slack area 13, as shown in FIG.
When the printing apparatus 1 generates the slack 14 on the roll paper P1, the rotary cutter when the transport amount of the roll paper P1 by the motor A10 has reached a predetermined transport amount X2, that is, the roll paper P1 reaches the cutting position. 5 starts to cut the roll paper P1. In this way, the printing apparatus 1 cuts the roll paper P1 by a predetermined length.

When the roll paper P1 is cut by the rotary cutter 5, the rear end of the roll paper P1 and the front end of the roll paper P1 of the next page are generated at the position indicated by the arrow B in FIG.
The rotary cutter 5 is connected to a cutter motor, and the cutter motor is driven under the control of the control unit 22 to cut the roll paper P1. The rotary blade of the rotary cutter 5 is preferably driven at a speed equal to or higher than the transport speed V2 of the roll paper P1.

  When the roll paper P1 is cut by the rotary cutter 5, the leading edge of the roll paper P1 reaches the transfer portion between the transfer roller 3 and the transfer belt 2, but the transfer portion and the blade of the rotary cutter 5 (fixed blade) Since the slack 14 is formed on the roll paper P1 between the rotary blade and the rotary blade, the impact of cutting by the rotary cutter 5 is absorbed by the slack 14 and is not propagated to the transfer portion.

  The slack generation unit 17 of the printing apparatus 1 cuts the roll paper P1 with the rotary cutter 5 (see X2 shown in FIG. 6), and then changes the conveyance speed of the conveyance roller A6 and the conveyance roller B7 by the motor A10 from the conveyance speed V2 to the motor B11. Is returned to the same transport speed V1 as the transport speed of the transport rollers C8 and D9 (see X3 shown in FIG. 6).

  After returning the conveyance speed of the motor A10 to the conveyance speed V1, the printing apparatus 1 passes the conveyance roller B7 and then the rear end of the roll paper P1 and the front end of the roll paper P1 on the next page. In order to ensure a predetermined interval, the rotation of the conveying roller A6 and the conveying roller B7 by the motor A10 is stopped until a predetermined time elapses (see X4 shown in FIG. 6).

The printing apparatus 1 continues to transport the roll paper P1 with the transport roller 8C and the transport roller D9 by driving the motor B11. At this time, the slack 14 formed on the roll paper P1 is completely eliminated.
The printing apparatus 1 transfers the toner image formed on the transfer belt 2 to the roll paper P1 at the transfer portion between the transfer roller 3 and the transfer belt 2 and fixes the toner image at the fixing portion 4.

  Note that the printing apparatus 1 stops the rotation of the motor A10 until a predetermined time has elapsed, and then rotates the motor A10 to start transporting the roll paper P1, and the image of the roll paper P1 on the next page in a state without slack. Start forming.

  In this manner, immediately before the roll paper P1 is cut by the rotary cutter 5, a slack is formed on the roll paper P1 between the transfer portion between the transfer roller 3 and the transfer belt 2 and the rotary cutter 5. As a result, the impact generated when the roll paper P1 is cut by the rotary cutter 5 is not propagated to the transfer portion, and therefore, the generation of shock lines that occur as disturbances in the image formed on the roll paper P1 in the transfer portion is suppressed. be able to.

In addition, after the roll paper P1 is cut by the rotary cutter 5, the slack 14 formed on the roll paper P1 is completely eliminated, so that the roll paper P1 is not conveyed in a state where the slack is held, and is stable. The rolled paper P1 can be conveyed.
Furthermore, a slack of an arbitrary size can be formed on the roll paper P1 due to the speed difference or acceleration timing of the motor that rotates the transport roller.

Therefore, control for detecting the amount of slack formed on the roll paper P1 using a sensor or the like is not required, and the roll paper P1 can be stably conveyed with a simple configuration and the roll paper P1 is cut. The occurrence of a shock line can be suppressed.
Here, a comparative example will be described with reference to FIGS. 7 is a schematic side sectional view showing the configuration of the printing apparatus in the comparative example, FIG. 8 is an explanatory view of the slack creation operation in the comparative example, and FIG. 9 is an explanatory view of the shock line generation in the comparative example.

  In FIG. 7, the printing apparatus 100 of the comparative example includes a transfer belt 102, a transfer roller 103, a fixing unit 104, a rotary cutter 105, a transport roller A106, a transport roller B107, a transport roller C108, and a transport roller D109. And motor A110, motor B111, sensor 112, slack area 113, and ID units 115K, 115C, 115Y, 115M, and 115W.

  The transfer belt 102, transfer roller 103, fixing unit 104, rotary cutter 105, transport roller A106, transport roller B107, transport roller C108, transport roller D109, motor A110, motor B111, slack area 113, and ID units 115K and 115C. 115Y, 115M, 115W are the transfer belt 2, transfer roller 3, fixing unit 4, rotary cutter 5, transport roller A6, transport roller B7, transport roller C8, transport roller D9, motor A10, motor B11, shown in FIG. Since the configuration is the same as the slack area 13 and the ID units 15K, 15C, 15Y, 15M, and 15W, the description thereof is omitted.

The sensor 112 detects the size of the slack of the roll paper P formed in the slack area 113.
As shown in FIG. 8, the leading edge of the roll paper P1 is nipped by the transport roller A106, and transport is started by driving the motor A110. The leading edge of the roll paper P1 passes through the rotary cutter 105, passes through the transport roller B107, and then comes into contact with the transport roller C108 to correct the skew of the roll paper P1.

  At this time, the motor A110 continues to rotate, the transport roller A106 and the transport roller B107 continue to transport the roll paper P1, and the motor B111 is stopped for a predetermined time, so that the leading edge of the roll paper P1 contacts the transport roller C108. It stops in contact with each other, and a slack 114 is generated on the roll paper P1.

  When the slack 114 is generated on the roll paper P1, the rotational drive of the motor B111 is started, and the leading end of the roll paper P1 is held in the transfer portion between the transfer belt 102 and the transfer roller 103. It is conveyed by. In the transfer unit, the toner image formed on the transfer belt 102 in parallel with the paper feeding operation at the leading edge of the roll paper P1 is rotated by the transfer roller 103 rotating at the same speed as the conveyance speed of the roll paper P1. Then, the toner image is fixed on the roll paper P1 in the fixing unit 104, and the roll paper P1 is discharged.

Here, the reason why the slack 114 is generated on the roll paper P1 is to correct the skew of the roll paper P1, but the other reason is that the roll paper P1 has an arbitrary length and the rotary cutter 105. This is to prevent the impact generated when cutting by the above from being propagated to the transfer portion.
When the roll paper P1 is cut in such a length that the leading edge of the roll paper P1 does not reach the transfer portion, the impact generated when cutting by the rotary cutter 105 affects the transfer of the toner image to the roll paper P1 in the transfer portion. There is no effect.

  However, when the roll paper P1 is cut with a length that the leading edge of the roll paper P1 reaches the transfer portion, the motor A110 and the motor B111 are rotated at the same speed as shown in FIG. When the roll paper P1 is cut, an impact generated when the roll paper P1 is cut by the rotary cutter 105 propagates through the roll paper P1 in the section indicated by an arrow C in the figure, and the toner image is transferred to the roll paper P1 at the transfer portion. A disturbing shock line occurs.

Therefore, as shown in FIG. 8, a slack 114 is generated on the roll paper P1, and an impact generated when cutting by the rotary cutter 105 is prevented from propagating to the transfer unit.
On the other hand, in the paper conveyance for forming an image on a continuous long paper such as the roll paper P1, the straightness of the paper conveyance is important. By continuing the paper conveyance while the straightness of the paper conveyance is disturbed, the meandering of the paper A paper jam or the like occurs due to the accumulation of misalignment.

The slackness of the paper during the conveyance of the paper is considered to be a cause of the meandering of the paper, and it is preferable to convey the paper in a state where a certain tension is applied to the paper in order to ensure straightness of the paper conveyance of the long paper.
This also applies to the case where the slack 114 is generated on the roll paper P1 so as not to generate a shock line. If the paper transport is continued while the slack 114 is held on the roll paper P1, the running of the roll paper P1 is stabilized. Accordingly, the image forming quality is adversely affected, for example, the image forming position is shifted.

In the present embodiment, immediately before the roll paper P1 is cut by the rotary cutter 5, a slack is formed on the roll paper P1 between the transfer portion between the transfer roller 3 and the transfer belt 2 and the rotary cutter 5. As a result, it is possible to suppress the occurrence of shock lines that occur as disturbances in the image formed on the roll paper P1 in the transfer portion.
In addition, after the roll paper P1 is cut by the rotary cutter 5, the slack 14 formed on the roll paper P1 is completely eliminated, so that the roll paper P1 is not conveyed in a state where the slack is held, and is stable. The rolled paper P1 can be conveyed.

  As described above, in this embodiment, a slack is formed in the roll paper between the transfer unit and the rotary cutter before the roll paper is cut, and the slack is eliminated in the roll paper after the roll paper is cut. As a result, it is possible to prevent the image from being disturbed when the continuous paper is cut and to ensure the stability of the continuous paper conveyance.

In this embodiment, the printing apparatus is described as an intermediate transfer type printing apparatus that uses a transfer belt and a transfer roller and transfers a toner image formed on the transfer belt by an ID unit onto a roll paper. Alternatively, a direct transfer type printing apparatus that conveys roll paper between the photosensitive drum of the ID unit and the transfer belt and directly transfers the toner image formed on the photosensitive drum onto the roll paper may be used.
Further, although an example in which continuous paper is roll paper has been described, the continuous paper may be fanfold paper and may be cut into an arbitrary page length.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Transfer belt 3 Transfer roller 4 Fixing part 5 Rotary cutter 6 Conveyance roller A
7 Transport roller B
8 Transport roller C
9 Transport roller D
10 Motor A
11 Motor B
13 slack area 13a, 13b paper guide 15K, 15C, 15Y, 15M, 15W ID unit 16 sensor 17 slack generation unit 21 storage unit 22 control unit

Claims (10)

A transport unit for transporting continuous paper;
A cutting unit disposed in the transport unit and configured to cut the continuous paper being transported;
An image forming unit that is arranged downstream of the cutting unit of the transport unit in the transport direction of the continuous paper and forms an image on the transported continuous paper;
A slack generating unit that generates a slack in the continuous paper conveyed between the cutting unit and the transfer unit;
Have
The slack generation unit generates slack in the continuous paper before the continuous paper is cut by the cutting unit and when the amount of the continuous paper transported reaches a predetermined amount. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the image forming unit is a transfer unit that transfers a developer image. The image forming apparatus according to claim 1, wherein:
The slack generation unit is
A first conveying means for conveying continuous paper;
A second conveying means arranged downstream of the first conveying means in the conveying direction of the continuous paper and conveying the continuous paper;
An image forming apparatus characterized in that a slack is formed on a continuous sheet by making the conveying speed of the first conveying means faster than the conveying speed of the second conveying means. The image forming apparatus according to claim 3.
Arranged upstream of the cutting section in the continuous paper conveyance direction, and provided with a detecting means for detecting the continuous paper,
The slack generation unit changes the conveyance speed of the first conveyance unit when the conveyance amount of the continuous sheet calculated with reference to the leading edge of the continuous sheet detected by the detection unit reaches a predetermined amount. Forming equipment. The image forming apparatus according to claim 3 or 4, wherein:
The slack generation unit returns the transport speed of the first transport unit to the same speed as the transport speed of the second transport unit after continuous paper is cut by the cutting unit. . The image forming apparatus according to any one of claims 3 to 5,
The image forming apparatus, wherein when the trailing edge of the continuous paper cut by the cutting unit passes through the first transport unit, the transport of the first transport unit is stopped. The image forming apparatus according to claim 3, wherein:
The image forming apparatus according to claim 1, wherein the first transport unit and the second transport unit are rollers that sandwich and transport continuous paper. The image forming apparatus according to any one of claims 3 to 7,
The image forming apparatus, wherein the cutting unit cuts the continuous paper being conveyed with a rotary blade. The image forming apparatus according to claim 8.
The image forming apparatus according to claim 1, wherein a speed of the rotary blade of the cutting unit is equal to or higher than a transport speed of the first transport unit. A transport unit for transporting continuous paper;
A cutting unit disposed in the transport unit and configured to cut the continuous paper being transported;
An image forming unit that is arranged downstream of the cutting unit of the transport unit in the transport direction of the continuous paper and forms an image on the transported continuous paper;
A slack generating unit that generates a slack in the continuous paper conveyed between the cutting unit and the transfer unit;
An image forming method of an image forming apparatus having
The slack generation unit generates slack in the continuous paper before the continuous paper is cut by the cutting unit, and when the continuous paper transport amount reaches a predetermined amount.

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