JPH0812125A - Sheet carrying device - Google Patents

Abstract

PURPOSE:To remove looseness of a sheet without exerting influence on carrying accuracy by driving the other in a condition where one of first and second carrying means is stopped to remove looseness of the sheet between the first and the second carrying means to sandwich and carry the sheet. CONSTITUTION:Recording paper is sandwiched and carried by both of first and second carrier roller pairs 8 and 11, and carrying speed of the recording paper 3 by the second carrier roller pairs 11 is set slightly faster than carrying speed by the first carrier rollers 8 so that the recording paper 5 does not become loose on a platen 10 by elongation or the like of the recording paper 3 by ink at carrying time of the recording paper 3 having a recording width W. Therefore, the recording paper 3 is carried while relatively sliding it to the second carrier roller pairs 11. When the recording paper rear end 3a gets out of the first carrier roller pairs 8, the second carrier roller pairs 11 are rotated by a quantity more than an elongation quantity of the recording paper 3 by ink, and looseness is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus applicable to image recording apparatuses such as copying machines, printers and facsimiles.

[0002]

2. Description of the Related Art Conventionally, in a recording apparatus which uses a serial scan method such as an ink jet recording method, a pair of conveying rollers for conveying recording paper as a sheet is provided on the upstream side and the downstream side of a recording unit, and a platen provided between them is provided. The recording paper was conveyed to the top for recording. First, a head carriage equipped with an inkjet recording head scans in a direction perpendicular to the transport direction to perform recording with a predetermined recording width by the inkjet recording head, and then transports a recording sheet by a recording width by a transport roller, Make the following recordings: This is repeated to record on the entire area of the recording paper.

At this time, when the recording amount of the recording width is conveyed, if the conveying amount is small, it overlaps with the next recording, and the overlapped portion becomes darker than an appropriate image, and if the conveying amount is large, the next recording is performed. The gap is opened and some areas are not recorded. Therefore, the recording paper for the recording width must be conveyed with high accuracy.

The upstream and downstream transport roller pairs are driven by the same pulse motor, and the downstream transport roller pair is set to have a larger transport amount and weaker clamping force than the upstream transport roller pair. The recording paper is always kept on the platen so as not to be slackened, and the conveyance amount of the recording paper conveyed by the upstream conveyance roller pair is not affected. In addition, when the trailing edge of the recording paper is conveyed by the recording width when it exits from the downstream conveying roller pair, depending on the length from the nip portion of the downstream conveying roller pair to the trailing edge of the recording paper, the upstream side Since the length of the portion conveyed by the pair of conveying rollers and the pair of downstream conveying rollers changes.
As disclosed in No. 1103, the number of drive pulses of the pulse motor is changed based on the length from the trailing edge of the recording paper to the nip portion of the upstream conveying roller pair, or the conveying amount is adjusted.
Proper recording has been performed by performing control such as changing the number of recording nozzles of the inkjet recording head.

[0005]

However, in the case of the above-mentioned prior art, when the trailing edge of the recording sheet is conveyed by the recording width when it comes out from the conveying roller pair on the downstream side, the trailing edge of the recording sheet and the downstream side are conveyed. Since the pulse motor and recording nozzle are controlled according to the length of the conveyance roller pair to the nip portion, the length between the trailing edge of the recording paper and the downstream conveyance roller pair nip portion can be detected and the paper size can be adjusted. For example, the length between the trailing edge of the recording paper and the nip portion of the downstream transport roller pair is detected and predicted.
However, with this method, the length between the trailing edge of the recording paper and the nip portion of the downstream conveying roller pair must be accurately detected, and the length of the recording paper cannot be estimated even if the length is predicted depending on the size of the recording paper. It was difficult to accurately control because it was not possible to cope with changes in length due to tolerances and humidity. In addition, since the ink is ejected onto the recording paper for recording, the recording paper swells and expands, causing the recording paper to sag on the platen, and the amount conveyed by the downstream conveying rollers is apparently reduced by the amount of expansion. However, it is difficult to control the conveyance of the recording paper more accurately. In particular, this effect was more remarkable as the width of the recording head became longer and the elongation of the recording paper by one recording width increased.

The present invention has been made in order to solve the above-mentioned problems of the prior art. In a recording medium conveying apparatus including a first conveying means and a second conveying means downstream thereof, a first conveying means is provided. It is an object of the present invention to remove the slack of a sheet generated between the conveying means and the second conveying means without affecting the conveying accuracy.

Particularly, in the present invention, when the trailing edge of the sheet is conveyed by a predetermined width when the trailing edge of the sheet exits from the downstream conveying roller pair which is the second conveying means, the sheet can be conveyed with high precision. A carrier device is provided.

A further object of the present invention is to provide a compact and inexpensive sheet conveying device.

Another object of the present invention is to provide a quiet and highly reliable sheet conveying device.

[0010]

The structure of the present invention for attaining the above object comprises a first conveying means for nipping and conveying a sheet, and a sheet arranged downstream of the first conveying means for conveying the sheet. A second conveying means for nipping and conveying, and in order to remove the slack of the sheet between the first conveying means and the second conveying means, A sheet conveying device characterized in that one of the sheets is driven while the other is stopped.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an image recording apparatus will be described below with reference to FIGS.

FIG. 1 is a cross-sectional view of the main part of an inkjet image recording apparatus embodying the present invention, and FIG. 2 is a top view of the main part of a carrying section of the inkjet image recording apparatus embodying the present invention. FIG. 3 is a perspective view of the main part of the recording unit. 4 to 8 are cross-sectional views of the main part of the carrying section for explaining the carrying state during recording, and FIG. 9 is a control block diagram.

A recording sheet 3 as a sheet stacked on a cassette 2 which is detachably attached to the bottom of the image recording apparatus 1.
Are fed by rotating the feed roller 4. The paper feed roller 4 is driven by a pulse motor 6 as a first drive source via a paper feed clutch 5 which is a breaking means for cutting off the driving force, a belt 6a and a pulley 5a. The paper feed clutch 5 receives a signal from the control circuit 30 as a control means to transmit the drive only when the paper is fed, and otherwise cuts off the drive transmission and rotates the pulse motor 6 even if the pulse motor 6 rotates. Does not rotate.

The fed recording paper 3 is guided by the transport guide 7 and is sent to the first transport roller pair 8 as a first transport means upstream of the ink jet head 21 which is a recording unit. The first conveyance roller pair 8 is composed of a first conveyance drive roller 8a and a pressure roller 8b, and the first conveyance drive roller 8a is driven by a second pulse motor 9 as a drive source via a belt 9a and a pulley 8c. To be done. The recording paper 3 conveyed by the first conveying roller pair 8 stops on the platen 10 and enters the state shown in FIG.

Next, the recording means will be described. As shown in FIG. 3, four ink jet heads 21 corresponding to four color inks of black, cyan, magenta and yellow are used.
The individually mounted head carriage 22 is scanned by a scanning motor 31 (not shown) along a rail 23 provided in the apparatus main body 1 in a direction perpendicular to the recording paper conveyance direction. At the time of scanning, the inkjet head 21 ejects ink toward the recording paper 3 based on an image signal given thereto, so that the inkjet head 21 performs recording with a recording width W of a predetermined length in the transport direction.

The first pulse motor 6, the second pulse motor 9 and the scanning motor 31 are controlled by the control circuit 31 as the control means shown in FIG.

The ink jet recording apparatus can record a high-definition image at a high speed, and since it is a non-impact system, it produces less noise, and it is easy to record a color image using multicolor inks. There are some advantages.

The recording head in the ink jet recording system has a liquid ejection port for ejecting and ejecting recording ink liquid as flying droplets, a liquid flow path communicating with the ejection port,
And a discharge energy generating means provided in a part of the liquid flow path and providing discharge energy for causing the ink liquid in the flow path to fly. Then, the ejection energy generating means is driven according to the image signal to eject ink droplets to generate an image.

As the ejection energy generating means, for example, a method of using pressure energy generating means such as an electromechanical converter such as a piezo element, or electromagnetic energy for irradiating and absorbing electromagnetic waves such as laser into the ink liquid to generate flying droplets is used. There is a method using a generating means, a method using an energy generating means for heating the liquid by an electrothermal converter such as a heating element having a heating resistor to eject the liquid.

Among them, in a recording head used in an ink jet recording system for ejecting a liquid by thermal energy, liquid ejection ports for ejecting recording liquid droplets to form ejection liquid droplets are arranged at high density. Therefore, it is possible to record with high resolution.

Further, among them, the recording head used as the heat energy generating means of the electrothermal converter can be easily made compact, and the IC technology and the micro technology which have been remarkably improved in the technological progress and reliability in the recent semiconductor field. This is advantageous because the advantages of processing can be fully utilized, high-density mounting is easy, and the manufacturing cost is low.

After the first recording by scanning the head carriage, the second pulse motor 9 is driven to rotate the first transport driving roller 8a to transport the recording paper 3 by the width W of the ink jet head 21, and Record the width of W. At this time, the leading end of the recording paper 3 is nipped by the second conveying roller pair 11 provided on the downstream side of the inkjet head, and the state shown in FIG. 5 is obtained. The second conveyance roller pair 11 is composed of a second conveyance drive roller 11a and a pressure roller 11b, and the second conveyance drive roller 11a drives the belt 6b and the pulley 11c by the first pulse motor 6 that drives the paper feed roller 4. Driven through.

When the recording paper W is conveyed with the recording paper nipped by both the first and second conveying roller pairs 8 and 11 shown in FIG. 5, recording by the second conveying roller pair 11 is performed. The paper conveyance speed is the same as that of recording paper 3 when recording with ink.
The rotation speed of the second pulse motor 9 is controlled so that the recording paper does not sag on the platen 10 due to the expansion of the sheet, so that it is slightly faster than the conveying speed of the first conveying roller pair 8 and is driven simultaneously. It has become. Further, the holding force of the second conveying roller pair 11 on the recording paper is set to be about 1/6 to 1/4 of the holding force of the first conveying roller pair 8 to set the recording paper 3 Is sandwiched between the first conveying roller pair, the recording paper is conveyed at the conveying speed of the first conveying drive roller 8a, and the conveying amount is determined by the rotation angle of the first conveying roller pair 8. ing. That is, the recording paper 3 is
It is conveyed while sliding relative to the second pair of conveying rollers 11.

Recording on the entire surface of the recording paper is performed by repeating the recording and conveying operations of the width W.

Finally, when the trailing edge 3a of the recording sheet 3 is conveyed from the first conveying roller pair 8 when the recording width W of the recording sheet 3 is conveyed, as shown in FIG. First, the recording paper 3 that is slackened on the platen 10 by being stretched is first recorded by ink.
In order to convey the downstream side of the recording unit by an amount larger than the amount of expansion of the recording sheet, the second pair of conveying rollers 11 is rotated by a predetermined amount for a predetermined time while the first conveying roller pair 8 is stopped. Is eliminated and the state shown in FIG. 7 is obtained.

The amount of rotation is set so as to be larger than the maximum length of expansion of the recording paper 3 with respect to the width W.
At this time, in the upstream side recording paper 3 nipped by the first conveying roller pair 8, the nipping force of the first conveying roller pair 8 is set to be stronger than the nipping force of the second conveying roller pair 11. Therefore, the second conveyance roller pair 11 does not move even if the recording paper 3 is pulled by rotation.

Further, if the second pulse motor is stopped in the excited state, the first conveying roller pair 8 will not be driven and rotated by the moving recording paper 3.

The case where the trailing edge of the recording paper comes out of the first conveying roller pair 8 means that the nip of the first conveying roller pair 8 is
This is the case where the distance to the trailing edge position of the recording paper before conveyance is smaller than the recording width W. This can be determined by calculating the length in the recording paper conveyance direction and the conveyance distance from the cassette 2 by the control circuit 30.

The length of the recording paper in the conveying direction can be determined from the size detected by the size detection sensor of the cassette 2. The transport distance can be obtained by calculating the total transport distance of the paper feed roller 4, the first transport drive roller 8a, and the second transport drive roller 11a by the control circuit 30.

The determination can also be made by providing the sensor 32 on the upstream side of the second conveying roller pair 8 and calculating the conveying distance after the trailing edge of the recording paper has passed.

Thereafter, the first conveying roller pair 8 and the second conveying roller pair 11 are simultaneously rotated by the first and second pulse motors so that they have the same speed, and the trailing edge 3a of the recording paper is the first conveying roller pair. The first conveyance roller pair 8 is used until it comes out of the first conveyance roller pair 8, and the second conveyance roller pair 11 is made to come out of the first conveyance roller pair 8 and 11 so that the recording width W is conveyed.
The state of FIG. 8 is assumed. Thereafter, the recording head performs recording of the width W, the recording is completed, and the second conveying roller pair 11 and the paper discharge roller 12 are rotated to discharge the recording paper onto the paper discharge tray 13.

As described above, the recording width at which the trailing edge of the recording paper comes out of the first conveying roller pair except for the drive sources of the first conveying roller pair on the upstream side of the recording section and the second conveying roller pair on the downstream side. In the case of the above-mentioned conveyance, first, the second conveyance roller pair provided on the downstream side is driven by a small amount to absorb the elongation due to the recording, and then the first and second conveyance roller pairs are driven to convey the recording paper. It is possible to carry with high precision, and it is possible to obtain uniform recording at the joints.

Further, by driving the paper feed roller with the drive source of the second conveying roller pair, it is possible to feed the recording paper without adding a motor, and it is possible to greatly reduce the cost.

In this embodiment, a signal is turned on as a shut-off means for shutting off the driving of the first pulse motor 6 for driving the second conveying roller 11 and the sheet feeding roller 4 which is the sheet feeding means. Although the paper feed clutch 5 that is turned off is used, the present invention is not limited to this. For example, a one-way clutch is used as a means for cutting off the drive, and the paper feed roller is rotated only when the first pulse motor is reversely rotated to feed the recording paper. Paper may be carried out, and then the pulse motor may be rotated in the forward direction. In this case, the paper feeding roller may be prevented from rotating and only the second carrying roller may be rotated to carry the recording paper.

(Explanation of Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS.

FIG. 10 is a cross-sectional view of the main part of an inkjet image recording apparatus embodying the present invention, and FIG. 11 is a top view of the main part of the carrying section of the inkjet image recording apparatus embodying the present invention. 12 to 17 are cross-sectional views of the main part of the transport unit for explaining the transport state during recording.

The configuration of the entire apparatus in this embodiment is as follows.
It is substantially the same as that described in the first embodiment, and the same portions are given the same reference numerals and the description thereof will be omitted.

In this embodiment, one pulse motor is used as a drive source for driving the first conveying roller pair and the second conveying roller pair.

The recording paper 3 loaded in the cassette 2 which is detachably provided at the bottom of the image recording apparatus 1 has the paper feed roller 4
The paper is fed by rotating the. The paper feed roller 4 is driven by a pulse motor 40 via a paper feed clutch 5, a belt 40a, and a pulley 5a. The paper feed clutch 5 and the pulse motor 40 are controlled by the control circuit 50. A signal is given to the paper feed clutch 5 from the control circuit 50 only during paper feed, and the drive is transmitted. At other times, the paper feed roller 4 does not rotate even if the pulse motor 40 rotates.

The fed recording paper 3 is guided by the conveying guide 7 and is sent to the first conveying roller pair 8 upstream of the ink jet head 21 which is a recording unit. The first conveyance roller pair 8 is composed of a first conveyance drive roller 8a and a pressure roller 8b, and the first conveyance drive roller 8a is driven by the pulse motor 40 via the clutch 41, the belt 40b, and the pulley 8c. The clutch 41 is a control circuit 5 if necessary.
A signal is given from 0 to transmit the drive, and at other times, the first transport roller 8a does not rotate even if the pulse motor 40 rotates. After the recording paper fed by the paper feed roller 4 reaches the first conveying roller pair 8, the clutch 41 is engaged and the first conveying roller 8a is driven to convey the recording paper 3 onto the platen 10 and drive the pulse motor 40. After stopping, the recording operation of the recording width W shown in the first embodiment is performed in the state shown in FIG. 3 of the first embodiment, and the process proceeds to the next operation.

After the recording by the first scanning of the head carriage 22, the pulse motor 40 is driven to rotate the first conveyance driving roller 8a, so that the recording paper 3 is conveyed by the width W of the ink jet head 21 and the next W Record the width. At this time, the front end of the recording paper 3 is the inkjet head 2
The state shown in FIG. 5 shown in the first embodiment is nipped by the second conveying roller pair 11 provided on the downstream side of 1. The second conveyance roller pair 11 is composed of a second conveyance drive roller 11a and a pressure roller 11b, and the second conveyance drive roller 11a is driven by the pulse motor 40 to drive the belt 40b and the pulley 11 together.
driven through c. When the first conveying roller 8a and the second conveying roller 11a are provided with the same reduction ratio and the same roller diameter with respect to the pulse motor 40 and the clutch 41 transmits the drive, the conveying speed and the conveying amount of the recording paper 3 are Be the same.

Recording is performed with the recording width W from the state shown in FIG. 5. After the recording, the recording paper is stretched and slackened by the ink, resulting in the state shown in FIG. From this state, the first transport roller pair 8 and the second transport roller pair 11 are rotated by the same amount, and the upstream portion and the downstream portion of the recording paper are transported by the transport amount W to obtain the state of FIG. In the state of FIG. 13, the recording paper is slackened and floated on the platen due to the expansion of the recording paper. Here, the pulse motor 40 is driven in a state where the signal of the clutch 41 is disengaged so that the drive is not transmitted and the first conveying roller is stopped, and the second conveying roller is rotated by a small amount to convey a minute amount on the downstream side of the recording paper. The state shown in FIG. 14 is set so that the recording paper does not sag on the platen. The value of this minute amount is set to a value slightly larger than the amount of elongation of the recording paper due to recording in order to surely eliminate the slack.

At this time, the holding force of the second conveying roller pair 11 with respect to the recording paper is about 6 of the holding force of the first conveying roller pair 8.
By setting it to about 1/4 to 1/4, the recording paper 3
In the state in which the sheet is nipped by the first conveying roller pair and stopped, the upstream recording sheet nipped by the first conveying roller pair does not move even when the second conveying driving roller 11a is driven, That is, the transfer amount W has been transferred.

Recording on the entire surface of the recording paper is performed by repeating the recording and conveying operations of the width W. Finally, when the trailing edge 3a of the recording sheet is conveyed through the first conveying roller pair 8 and the recording width W of the recording sheet 3 is conveyed, as shown in FIG.
Platen 1 by stretching due to recording as shown at 5
For the recording paper 3 slacked on 0, first, the clutch 41 is released to convey the downstream side of the recording unit by an amount larger than the amount of expansion of the recording paper 3 due to recording with ink, and the first conveyance roller is released. With the pair stopped, the pulse motor 40 is driven to rotate the second conveying roller pair 11 for a predetermined amount of time for a predetermined amount to eliminate the slack due to the elongation of the recording paper, and the state shown in FIG. 16 is obtained. The amount of rotation is set to be larger than the maximum length of extension of the recording paper 3 with respect to the width W. At this time, the upstream side recording paper 3 nipped by the first conveying roller pair 8
Means that the holding force of the first conveying roller pair 8 is the second conveying roller pair 1
Since the holding force of 1 is set to about 1/6 to 1/4, the second conveying roller pair 11 does not move even if the second conveying roller pair 11 rotates and pulls the recording paper 3.

After that, the first conveying roller pair 8 and the second conveying roller pair 11 are simultaneously rotated at the same speed, and the trailing edge 3 of the recording paper is rotated.
17a is conveyed by the first conveyor roller pair and the second conveyor roller pair 8 and 11 until it comes out of the first conveyor roller pair 8, and then it is conveyed by the second conveyor roller pair 11 after it is removed.
State. At this time, the first and second conveying roller pairs 8,
The carry amounts of 11 are both the length of the recording width W.

Thereafter, the recording head records the width W, the recording is completed, and the second conveying roller pair 11 and the paper discharge roller 12 are rotated to discharge the recording paper onto the paper discharge tray 13.

As described above, the clutch serving as a means for interrupting the driving force is provided between the motor and the first conveying roller pair, the first and second conveying roller pairs are driven by one motor, and the trailing edge of the recording paper is When the recording width is to be conveyed out of the first conveying roller pair, first the clutch is disengaged and only the second conveying roller pair provided downstream is driven by a minute amount without driving the first conveying roller pair to increase the elongation due to recording. By absorbing and then connecting the clutch and driving the first and second conveying roller pairs to convey the recording paper, it is possible to perform highly accurate conveyance at very low cost, and obtain uniform recording at the joint. .

In the above first and second embodiments,
Although the printer using the inkjet recording method has been described, it goes without saying that a copying machine equipped with an image reading device may be used.

In the above first and second embodiments,
The slack of the sheet was removed by driving the second conveying unit in the direction in which the sheet is conveyed to the downstream side with the first conveying unit stopped, but with the second conveying unit stopped. Then, the slack of the sheet may be removed by conveying the first conveying means to the upstream side. In this case, the sum of the upstream transport amount and the downstream transport amount by the first transport means is controlled to W.

Further, the slack may be removed by carrying out the upstream transfer by the first transfer means and the downstream transfer by the second transfer means at the same time. In this case as well, the sum of the amount of upstream transport and the amount of downstream transport by the first transport means is W.
Control to become.

Further, instead of the ink jet head in the above embodiment, the present sheet material conveying apparatus is also applied to an image reading apparatus in which a CCD for reading an image of a sheet material while scanning an original sheet material is scanned in a direction perpendicular to the conveying direction. it can.

Further, the first and second conveying means sandwiches the sheet by a pair of rotating bodies, for example, includes a pair of rollers used in the above-mentioned embodiment, and further comprises a pair of conveying belts. , One including a conveyor belt and the other including a roller.

In the above-described embodiment, in the recording medium conveying device having the first conveying means and the second conveying means downstream thereof, the second conveying means provided on the downstream side is the first conveying means. By driving the recording medium in the downstream direction for a predetermined period of time before driving, the trailing edge of the recording paper is conveyed by the second conveying means by driving the first conveying means and the second conveying means. The recording paper can be conveyed with high accuracy in the case of the conveyance of the recording width when exiting from the conveying roller pair on the downstream side, which is the means.

Further, in a conveying device which is provided with the first conveying means and the second conveying means downstream thereof and which intermittently feeds the recording medium by a predetermined width, it is possible to convey the recording paper with high accuracy. Can be provided.

Further, it is possible to provide a recording medium carrying device provided with a carrying means for carrying a recording medium with high accuracy.

Furthermore, it is possible to provide a recording medium conveying device provided with a small and inexpensive recording medium conveying means.

Further, it is possible to provide a quiet and highly reliable image recording apparatus which is downsized and inexpensive.

[0058]

As described above, the present invention has been made to solve the above-mentioned problems of the prior art, and provides a recording medium having a first conveying means and a second conveying means downstream thereof. In the transport device, the slack of the sheet generated between the first transport means and the second transport means can be removed without affecting the transport accuracy.

Particularly, in the present invention, when the trailing edge of the sheet is conveyed by a predetermined width when the trailing edge of the sheet exits from the downstream conveying roller pair which is the second conveying means, the sheet can be conveyed with high accuracy. A carrier device can be provided.

Further, the present invention can provide a small and inexpensive sheet conveying device.

Further, the present invention can provide a quiet and highly reliable sheet conveying device.

[Brief description of drawings]

FIG. 1 is a main part sectional view showing a configuration example of an inkjet image recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a top view of the main part of the transport section showing a configuration example of the inkjet image recording apparatus according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a main part of a recording unit showing a configuration example of the inkjet image recording apparatus according to the first embodiment of the invention.

FIG. 4 is a main-portion cross-sectional view of a transport section illustrating a transport state during recording of the image recording apparatus according to the first embodiment of the present invention.

FIG. 5 is a main-portion cross-sectional view of the transport section showing the transport state at the time of recording in the image recording apparatus according to the first embodiment of the present invention.

FIG. 6 is a main-portion cross-sectional view of a transport section illustrating a transport state during recording in the image recording apparatus according to the first embodiment of the present invention.

FIG. 7 is a main-portion cross-sectional view of a transport section illustrating a transport state during recording in the image recording apparatus according to the first embodiment of the present invention.

FIG. 8 is a main-portion cross-sectional view of a transport section illustrating a transport state during recording of the image recording apparatus according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a control block diagram of the image recording apparatus according to the first embodiment of the present invention.

FIG. 10 is a cross-sectional view of main parts showing a configuration example of an inkjet image recording apparatus according to a second embodiment of the present invention.

FIG. 11 is a top view of a main portion of a transport section showing a configuration example of an inkjet image recording apparatus according to a second embodiment of the invention.

FIG. 12 is a main-portion cross-sectional view of a transport section illustrating a transport state at the time of recording of the image recording apparatus according to the second embodiment of the present invention.

FIG. 13 is a main-portion cross-sectional view of the transport section showing the transport state during recording in the image recording apparatus according to the second embodiment of the present invention.

FIG. 14 is a main-portion cross-sectional view of a transport portion illustrating a transport state at the time of recording of the image recording apparatus according to the second embodiment of the present invention.

FIG. 15 is a main-portion cross-sectional view of the transport section showing the transport state during recording in the image recording apparatus according to the second embodiment of the present invention.

FIG. 16 is a main-portion cross-sectional view of the transport section showing the transport state during recording in the image recording apparatus according to the second embodiment of the present invention.

FIG. 17 is a main-portion cross-sectional view of the transport section showing the transport state during recording in the image recording apparatus according to the second embodiment of the present invention.

[Explanation of symbols]

 2 cassette 3 recording paper 4 paper feed roller 5 paper feed clutch 6, 9, 40 pulse motor 8 first transport roller pair 11 second transport roller pair 21 inkjet head 41 clutch

Claims (20)

[Claims] 1. A first transporting unit for sandwiching and transporting a sheet, and a second transporting unit disposed downstream of the first transporting unit for sandwiching and transporting the sheet, wherein: In order to remove the slack of the sheet between the first conveying means and the second conveying means, one of the first and second conveying means is stopped and the other is driven. Sheet transport device. 2. The driving of the second transporting means in a state where the first transporting means is stopped in order to remove the slack of the sheet between the first transporting means and the second transporting means. The sheet conveying apparatus according to claim 1, wherein 3. The slack of the sheet between the first transporting means and the second transporting means is removed by driving the second transporting means while the first transporting means is stopped. The sheet conveying apparatus according to claim 2, wherein the first and second conveying units are configured to be driven later by an equal conveying amount. 4. The first and second transporting means are driven by an equal transporting amount, and then the first slackening sheet is removed between the first and second transporting means. 3. The sheet conveying apparatus according to claim 2, wherein the second conveying unit is driven while the first conveying unit is stopped. 5. In order to remove the slack of the sheet between the first conveying means and the second conveying means, one of the first and second conveying means is stopped and the other is driven. A sheet conveying device characterized by performing. 6. The first and second conveying means intermittently feeds a sheet by a predetermined distance.
The sheet conveying device described. 7. The sheet conveying apparatus according to claim 1, wherein the driving sources for driving the first conveying unit and the second conveying unit are different from each other. 8. The sheet conveying apparatus according to claim 7, wherein a driving source for driving the second conveying unit is the same as a driving source for the sheet feeding unit. 9. The sheet conveying apparatus according to claim 8, further comprising a cutoff unit that cuts off the transmission of the driving force between the sheet feeding unit and the drive source. 10. The drive source of the first transport means and the drive source of the second transport means are the same, and a shutoff means for shutting off transmission of driving force between the first transport means and the drive means is provided. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus. 11. The sheet conveying apparatus according to claim 1, wherein the sheet nipping force of the first conveying unit is larger than the sheet nipping force of the second conveying unit. 12. The sheet according to claim 1, further comprising recording means for recording an image on a sheet conveyed between the first conveying means and the second conveying means. An image recording apparatus comprising a conveying device. 13. The image recording apparatus according to claim 12, wherein the recording means is an ink jet type image recording means for ejecting ink droplets. 14. The image recording apparatus according to claim 13, wherein the recording unit has an element that generates thermal energy that causes film boiling in the ink as energy used for ejecting ink. . 15. The first and second transporting means stop after transporting a sheet for a predetermined length, and the first and second transporting means stop.
13. The image recording apparatus according to claim 12, wherein the recording unit records the image of the predetermined length on the sheet when the conveying unit of the recording medium is stopped. 16. The image recording apparatus according to claim 15, wherein the first and second conveying means remove the slack of the sheet after the recording means records a predetermined length. 17. The image according to claim 15, wherein the first and second conveying means convey the sheet by a predetermined length after the recording means records a predetermined length. Recording device. 18. A first transporting means for sandwiching and transporting a sheet, and a second transporting means arranged downstream of the first transporting means for sandwiching and transporting the sheet, wherein: A sheet conveying apparatus, wherein at least one of the first and second conveying means is driven in order to remove the slack of the sheet between the first conveying means and the second conveying means. 19. A first conveyance means for nipping and conveying a sheet, and a second conveyance means arranged downstream of the first conveyance means for nipping and conveying the sheet, wherein: The second transport means is driven before the first transport means is driven to remove the slack of the sheet between the first transport means and the second transport means, and then the first transport is performed. A sheet conveying device, characterized in that the sheet conveying means drives the second conveying means. 20. A sheet conveying device comprising a first conveying means and a second conveying means downstream thereof, for intermittently feeding a sheet by a predetermined distance, wherein the first conveying means and the second conveying means are provided. When the sheet is intermittently fed by a predetermined width in both, the conveying speed or the conveying distance of the second conveying means is set to be higher than the conveying speed or the conveying distance of the first conveying means,
In the case of intermittent feeding when the sheet comes out of the first conveying means, the conveying speed of the first conveying means is the same as that of the second conveying means or at least until the sheet comes out of the first conveying means. A recording medium conveying device having the above speed.