JP2002332128A - Recording device and sheet material carrying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constantly make a butting amount optimal in adjusting a traveling direction of a paper. SOLUTION: A paper feeding roller 11 for carrying a paper of a predetermined carried amount by one time carrying operation and making the paper in a free state after the carrying operation, an LF roller 30 for further carrying the paper carried by the paper feeding roller 11, a PE sensor 35 for detecting passage of a tip end of the paper carried by the paper feeding roller 11, and an ASF sensor 36 for detecting rotation quantity from a predetermined rotating position of the paper feeding roller 11 are included. The rotation quantity of the paper feeding roller 11 from when the ASF sensor 36 is turned on to when the PE sensor 35 is turned on is detected. When a deficiency of the carried amount obtained from the detected rotation quantity is not more than a predetermined value, the paper of a certain amount is carried again by the paper feeding roller 11, and when exceeds the predetermined value, the paper of a variable amount is carried again by the paper feeding roller 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus having a mechanism for adjusting a traveling direction of a sheet material (for example, paper) and conveying the sheet material to a recording section, and a sheet material conveying method performed in such an apparatus.

[0002]

2. Description of the Related Art As a means for transporting paper to a recording unit, an automatic paper feeder for transporting sheets one by one and a paper transported from the automatic paper feeder are fed to the recording unit. A paper feeding unit. 2. Description of the Related Art As an automatic paper feeder, there is known an automatic paper feeder in which a paper feed roller that separates and conveys sheets one by one from a sheet stacking section on which a plurality of sheets are stacked is controlled by one rotation in one direction.

FIG. 21 is a partial cross-sectional view showing a system for conveying a sheet to a recording unit in a conventional recording apparatus having an automatic sheet feeding apparatus in which a sheet feeding roller is controlled by one rotation in one direction. The transport system includes a sheet stacking unit 2 on which a plurality of sheets 201 are stacked.
00, a paper feed roller 202 that separates and conveys the paper one by one from the paper stacking unit 200, and an LF roller 203 that feeds the paper 201 separated and conveyed by the paper feed roller 202 to a recording unit (not shown). Paper loading section 200
The paper feed roller 202 forms an automatic paper feeder, and the LF roller 203 forms a paper feed unit. In addition, although not shown, the sheet feeding roller 202
A first sensor unit for detecting the rotation position of the paper feed roller 2
A second sensor unit that detects that the leading end of the sheet 201 separated and conveyed by No. 02 has passed a predetermined place.

In a recording apparatus having the above-described transport system, automatic paper feed control is performed as follows.

First, the paper feed roller 202 is rotated to start a paper feed operation. When the paper feeding operation is started, subsequently, the calculation of the rotation amount of the paper feeding roller 202 based on the output of the first sensor unit is started, and when the leading end of the paper 201 is detected by the second sensor unit. Then, it is determined from the amount of rotation of the paper feed roller 202 how much the paper 201 has been conveyed. And
The following operation is performed based on the determined transport amount of the sheet 201.

If the transport amount of the paper 201 is sufficient,
The paper 201 is conveyed to the recording unit as it is by the LF roller 203. If the transport amount of the paper 201 is insufficient, it is determined that the transport amount is insufficient due to a slip or the like occurring between the paper 201 and the paper feed roller 202, the paper feeding operation is stopped, and the paper 201 is recorded. The recording apparatus is ejected outside the apparatus, or the recording apparatus is stopped due to a paper feed error or the like.

In addition to the above, when the transport amount of the paper 201 is insufficient, control is also performed such that the paper feed roller 202 is rotated again to feed the paper 201 with the insufficient transport amount to the paper feeding unit. is there.

[0008]

However, the conventional recording apparatus has the following problems.

If the feeding amount of the paper 201 is insufficient, the paper feeding operation is stopped and the paper 201 is discharged out of the recording apparatus, or if the recording apparatus is stopped due to a paper feeding error or the like, the paper feeding operation is performed again. Therefore, it takes time and labor, and the time required for printing (total time) also becomes longer.

[0010] In the case of performing a re-feed operation,
Since the amount of paper hitting the paper nip (pressing amount) during refeeding was roughly calculated, the paper was damaged due to excessive feeding when adjusting the paper advance direction at the paper nip. There is a risk that it will.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording apparatus and a sheet material conveying method capable of solving the above-mentioned problems and always optimizing a pushing amount when adjusting a traveling direction of a sheet material such as paper. Is to do.

[0012]

In order to achieve the above object, a recording apparatus according to the present invention comprises a first conveying means for conveying a printable sheet material, and a sheet material conveyed by the first conveying means. A second conveying means which is abutted and conveyed by a predetermined pushing amount, a detecting means for detecting a conveying state of the sheet material by the first conveying means, and a detecting means of the sheet material detected by the detecting means. It is determined from the transport state whether the transport distance of the sheet material by the first transport unit is insufficient.
Control means for causing the sheet material to be re-conveyed by the convey means, wherein the control means performs the re-conveyance of the first convey means when the first convey means re-conveys, The transport amount is switched between a fixed amount and a variable amount to secure the predetermined pushing amount.

[0013] In the above case, the first conveying means conveys the sheet material by a predetermined conveying amount in one conveying operation and sets the sheet material in a free state after the conveying operation. The control unit is configured such that, from the conveyance state of the sheet material detected by the detection unit, the leading end of the sheet material after the one-time conveyance operation reaches the second conveyance unit in the free state. It is determined whether the first state exists or the second state has not reached the second transport means.
In the case of the state, the first conveying means conveys the sheet material again by a fixed amount, and in the second state, the second conveying means moves from the front end of the sheet material to the fixed amount. The sheet material may be conveyed again by the first conveying means by an amount obtained by adding the distance to the sheet material.

In the sheet conveying method according to the present invention, a first conveying means for conveying a printable sheet material, and a leading end of the sheet material conveyed by the first conveying means is abutted by a predetermined pushing amount. A sheet conveying method performed in an apparatus having a second conveying unit conveyed by
A first step of detecting a conveyance state of the sheet material by the first conveyance unit, and judging a shortage of the conveyance amount of the sheet material by the first conveyance unit from the detection result;
If it is determined in step (a) that the transport amount of the sheet material is insufficient, the first transport means is caused to re-transport the sheet material, and the transport amount at the time of the re-transport is set to the transport amount of the sheet material. A second step of switching between a fixed amount and a variable amount according to the shortage of the amount to secure the predetermined pushing amount.

In the above case, the first conveying means conveys the sheet material by a predetermined conveying amount in one conveying operation, and sets the sheet material in a free state after the conveying operation. In the first step, the leading edge of the sheet material after the one-time transport operation reaches the second transport means in the free state from the detected transport state of the sheet material. Determining whether the first state is present or the second state has not reached the second transport means, and the second step includes determining the first state and the first state in the first step. If it is determined, the first conveying means conveys the sheet material again by a fixed amount, and if it is judged that the sheet is in the second state, the sheet material is conveyed to the fixed amount from the front end of the sheet material by the second amount. By the amount obtained by adding the distance to the conveying means It may include the step of conveying the sheet again by the conveying means.

According to the present invention as described above, the above-mentioned problem is solved by the following operation.

The leading end of the sheet conveyed by the first conveying means is abutted against the second conveying means by a predetermined pushing amount. In this way, by abutting the sheet material against the second conveying means with a predetermined pushing amount,
The conveying direction of the sheet material can be adjusted. However, if a slip or the like occurs during conveyance of the sheet material by the first conveyance means, the conveyance amount of the sheet material is insufficient, and a predetermined pushing amount cannot be obtained, or the leading end of the sheet material reaches the second conveyance means. In some cases, it is impossible to adjust the sheet material conveyance direction. When the transport amount of the sheet material is insufficient, the first transport means re-transports the sheet material. In this re-conveyance, if the pushing amount is simply insufficient, the re-conveyance amount may be a fixed amount. However, if the leading end of the sheet material does not reach the second conveying means, the re-conveyance amount is a variable amount. It is necessary to According to the present invention, the re-conveyance amount is switched between a fixed amount and a variable amount according to the shortage amount of the conveyed amount of the sheet material to secure a predetermined abutting amount. In addition, when adjusting the traveling direction of the sheet material, there is no problem that the sheet material is damaged due to excessive feeding.

In the case where the first transport means is configured such that the sheet material is transported by a predetermined transport amount in one transport operation, and the sheet material is in a free state after the transport operation. When the transport amount of the sheet material becomes insufficient due to a slip or the like when the sheet material is transported by the first transport unit, the time when one transport operation by the first transport unit is completed according to the insufficient amount. Then, the first state in which the leading end of the sheet material has reached the second conveying means, or the second state in which the sheet material has not reached the second conveying means. First
In this case, if the first conveying means conveys the sheet material by a fixed amount, the sheet material can always be supplied to the second conveying means with an optimum pushing amount. On the other hand, in the case of the second state, an amount obtained by adding the distance (deficient amount) from the leading end of the sheet material to the second conveying means to the conveying amount (constant amount) in the first state is used. If the sheet material is conveyed by the first conveying means, the sheet material can always be supplied to the second conveying means with an optimum pushing amount.
According to the present invention, the above-described control is performed, and the sheet material is always supplied to the second conveying means with the optimum pushing amount.

Further, in the present invention, the sheet material having the insufficient conveyance amount is conveyed again to obtain the optimum pushing amount, so that the sheet feeding operation is stopped and the sheet material (paper ) Need not be discharged out of the recording apparatus or the recording apparatus must be stopped due to a paper feed error or the like.

[0020]

Next, embodiments of the present invention will be described with reference to the drawings.

According to the recording apparatus of the present invention, an automatic sheet feeding device as a first conveying means for separating and conveying one sheet at a time from a plurality of sheets stacked on a sheet stacking section; A paper feed unit as a second transport means for feeding the paper transported from the apparatus to the recording unit, wherein the paper transported from the automatic paper feeder is always pressed against the paper transport unit by an optimal pushing amount. Thus, the traveling direction of the sheet is adjusted.

First, the configuration of the automatic paper feeder provided in the recording apparatus of the present invention will be described. FIG. 2 is a schematic perspective view showing an example of the automatic paper feeder, and FIG. 3 is a schematic front view of the automatic paper feeder shown in FIG.

In FIGS. 2 and 3, reference numeral 11 denotes a paper feed roller for conveying the paper, reference numeral 10 denotes a paper feed shaft supporting the paper feed roller 11, and reference numeral 11 'denotes a paper feed assist by the paper feed roller 11. 12 is a separation roller for separating paper, 12b is a torque limiter, 13 is a return lever for preventing double feed, 14 is a return lever control cam for driving the return lever 13, and 15 is an automatic paper feeder (automatic feeder). ASF base, which is a frame of the sheet feeder (ASF), 1
Reference numeral 6 denotes a pressure plate that presses the loaded paper toward the paper feed roller 11, reference numeral 18 denotes a side guide for positioning in a direction intersecting (perpendicular to) the paper transport direction Y, and reference numeral 19 denotes contact of the paper with the paper feed roller 11. Is a separation roller pressing spring, and 28 is a torque limiter holder.

The configuration of the automatic sheet feeding apparatus of this embodiment is roughly divided into a sheet stacking section, a sheet feeding / separating section, and a double feed preventing section. Hereinafter, each component will be described in detail.

(1) Sheet loading section: The sheet loading section is a pressure plate 1
6. Paper loading surface 15b, paper transport reference portion 1 serving as a reference for the setting position of the paper set on this paper loading surface 15b
5a, a side guide 18 for regulating the width direction of the set sheet. The portion forming the sheet stacking surface 15b has a rib shape, so that the load at the time of sheet feeding can be reduced, and the sheet can be set smoothly.

The paper transport reference portion 15a is an ASF base 1
5 is provided so as to protrude from a part thereof. Side guide 1
Numeral 8 is movable in a direction intersecting (perpendicular to) the sheet conveying direction Y. The side guide 18 and the sheet conveyance reference portion 15a position the sheet set on the sheet stacking surface 15b.

The pressure plate 16 has a rotation moving mechanism having a rotation center at an upper end, and the automatic sheet feeding device is not conveying a sheet.
In a so-called standby state, the paper feed roller 1 is fixed at a predetermined position away from the paper feed roller 11 by a predetermined distance.
1 to carry the sheet, the sheet loading surface 15b
Is rotated so as to press the paper set on the paper feed roller 11 side. In the standby state, a sufficient gap is provided between the pressure plate 16 fixed at a predetermined position and the sheet feeding roller 11 to stack a plurality of sheets on the sheet stacking surface 15b.

The urging of the pressure plate 16 in the direction of the paper feed roller 11 and the separation of the pressure plate 16 from the paper feed roller 11 are basically performed by a spring and a cam. Specifically, the rotation of the pressure plate 16 in the direction of the paper feed roller 11 is performed by a pressure plate spring. When the pressure plate 16 is separated from the paper supply roller 11, the cam is forcibly rotated by pressing the pressure plate 16. It is done by being done.

The sheet stacking section is designed to adapt to an arbitrary sheet width within a predetermined sheet width range.
At the time of paper setting, a plurality of papers are set along the paper transport reference portion 15a in a gap between the pressure plate 16 and the paper feed roller 11 with the pressure plate 16 fixed at a predetermined position. The width direction of each set sheet is adjusted by moving the side guide 18 in the direction of arrow C shown in FIG. Thereby, the set stacked paper bundle is restricted from moving in a direction intersecting (perpendicular to) the paper transport direction Y, and stable transport is possible.

The loaded stack of sheets is urged downward by gravity, and the leading end of the stack hits the sheet stacking surface 15 b fixedly provided on the ASF base 15. In this state, by rotating the pressure plate 16 toward the paper feed roller 11 by the pressure plate spring, the set stacked sheets are pressed (rotationally urged) by the paper feed roller 11.

When the paper is set again, the pressure plate 16 is forcibly moved by the cam to a predetermined position separated from the paper feed roller 11 by a predetermined distance.

The above-described urging / separating operation is performed at a predetermined timing, which will be described later, so that the sheet feeding operation is performed.

Although the side guide 18 is slidably attached to the pressure plate 16, the side guide 18 may be fixed by engaging with a latch groove formed in the pressure plate 16 so as not to move carelessly. In this case, for example, a lever portion for releasing the latch may be provided on the side guide 18, and when the side guide 18 is moved, the latch may be released by operating the lever portion.

(2) Paper feed / separation unit: The paper feed / separation unit includes the paper feed roller 11, the auxiliary roller 11 ', the separation roller 12, and the separation roller pressing spring 26. The paper feed roller 11 and the auxiliary roller 11 ′ are supported by a paper feed shaft 10, and rotate in a predetermined direction when a rotational driving force is applied to the paper feed shaft 10 from a motor (not shown). Paper feed roller 1
1 is pressed by the sheet stacking unit at the sheet stacking unit, and when the sheet feeding roller 11 is rotated, the uppermost sheet of the stacked sheets contacting the sheet feeding roller 11 is fed to the sheet feeding roller. It is conveyed by the frictional force with 11. As described above, since the paper feed roller 11 conveys the paper by the frictional force,
It is more preferable to use rubber having a high coefficient of friction such as EPDM, urethane foam, or the like as the material. The auxiliary roller 11 'assists the paper transport by the paper feed roller 11.

The separation roller 12 is provided so as to abut on the downstream side in the transport direction from the point where the paper feed roller 11 and the paper set in the paper stacking section first come into contact. The separation roller pressing spring 26 connects the separation roller 12 to the sheet feeding roller 11.
This is a pressing means for pressing the button.

A torque limiter 12b is provided on the rotation center shaft of the separation roller 12. This torque limiter 1
2b itself is only rotatably held by the torque limiter holder 28, and no active rotation drive is performed. However, the support shaft of the torque limiter 12b is fixed, and a coil spring made of metal or plastic is stored between the fixed support shaft and the torque limiter 12b. When the coil spring is wound around the support shaft by rotating to an angle, the coil spring and the support shaft slide relatively to maintain a predetermined torque. Also, the surface of the separation roller 12 has the same friction coefficient as that of the paper feed roller 11,
It is made of rubber or urethane foam.

Next, the operation of the paper feed / separation unit will be described.

In the state where the stack of paper sheets set in the paper stacking section is pressed by the paper feed roller 11, the paper feed roller 1
When the roller 1 is driven to rotate, the uppermost sheet of the stacked sheets in contact with the sheet feeding roller 11 is conveyed by the frictional force with the sheet feeding roller 11. As described above, the uppermost sheet of the stacked sheets is conveyed by the feed roller 11. Basically, the frictional force between the feed roller 11 and the uppermost sheet is limited to the uppermost sheet and the sheet immediately below the uppermost sheet. If the frictional force is larger than the above, only the uppermost sheet can be conveyed.

However, for example, when there is an influence of burrs at the end of the sheet when cutting the sheet, when there is sticking between sheets due to static electricity, or when a sheet having a very large surface friction coefficient is used, the A plurality of sheets may be pulled out by the roller 11 at one time. For this reason, in the present example, the separation operation using the torque limiter 12b described below is performed by the separation nip formed by the feed roller 11 and the separation roller 12, and only the uppermost sheet is separated and conveyed.

When there is no paper in the separation nip,
The separation roller 12 is driven to rotate with the rotation of the paper feed roller 11. If one sheet enters the separation nip,
Since the frictional force between the paper feed roller 11 and the paper is larger than the frictional force between the separation roller 12 driven by a predetermined torque by the action of the torque limiter 12b and the paper, the paper feed roller 1
The sheet is conveyed while the separation roller 12 is driven by the rotation of 1.

When two sheets enter the separation nip,
The frictional force between the paper feed roller 11 and the paper on the paper feed roller 11 side is larger than the frictional force between the papers.
Since the frictional force between the paper on the second side and the separation roller 12 is greater than the frictional force between the papers, slippage occurs between the papers. As a result, only the paper on the paper feed roller 11 side is conveyed, and the separation roller 12 is not rotated, and the paper on the separation roller 12 side stops at that location and is not conveyed.

(3) Double feed prevention unit: the above-described paper feed roller 11
In the separation nip constituted by the separation roller 12 and the separation roller 12, when two sheets enter, only the sheet located on the sheet supply roller 11 side can be separated and conveyed. However, when three or more sheets enter, or after two sheets enter and only the sheet on the feed roller side is conveyed, the next sheet is fed continuously while leaving the sheet near the nip. In such a case, there is a possibility that a so-called double feed, in which a plurality of sheets are conveyed at the same time, occurs. The double feed prevention unit is for preventing this.

The double feed prevention unit includes a return lever control cam 14 and a return lever 13. The rotation operation of the return lever 13 is performed in synchronization with the rotation operation of the return lever control cam 14. In the case of this example, three return levers 13 are provided, each of which is integrally formed on one shaft. Further, two of the three return levers 13 are provided with the sheet feeding roller 1.
1 is disposed at a position sandwiching the same.

In the double feed prevention section, each return lever 13 is rotated by a predetermined amount by rotating the return lever control cam 14 in a predetermined direction by a drive motor (not shown). When each return lever 13 rotates, it comes into contact with the leading end of the paper left near the nip, and pushes the paper back in the direction opposite to the paper transport direction. Thus, the sheet left near the nip returns to the original position.

The automatic paper feeder configured as described above
Since it has no complicated mechanism, its control is easy.

The above is a brief description of the automatic paper feeder provided in the recording apparatus of the present invention.

Next, a recording apparatus of the present invention provided with the above-described automatic paper feeder will be described. FIG. 1 is a schematic sectional view of a recording apparatus according to an embodiment of the present invention.

Referring to FIG. 1, this recording apparatus is provided with a chassis 38 provided with the automatic paper feeder shown in FIGS. 2 and 3 and a transport system for transporting the paper fed from the automatic paper feeder. Have been. In the example of FIG. 1, the automatic sheet feeding device includes the pressure plate spring 17 for pressing the pressure plate 16 against the sheet feeding roller 11, and the configuration and operation are as described above. Therefore, the description of the specific configuration of the automatic sheet feeder is omitted here.

The transport system is provided with an LF roller 30 for feeding a sheet, a pinch roller 31 for applying a contact pressure to the sheet, and a pinch roller 31 for applying a contact pressure to the sheet. A pinch roller holder 33 for freely holding and guiding the paper, a PE lever 34 for detecting the leading edge of the paper, a PE sensor 35 for detecting the movement of the PE lever 34, and a paper feed roller 11. An ASF sensor 36 for detecting a position, an electric board 37,
The printing apparatus includes a platen 39 for holding the lower surface of the sheet being fed, a sheet discharging roller 40 for discharging the sheet out of the recording apparatus, and a spur 41.

The LF roller nip portion (paper feed portion) comprising the PE lever 34, the LF roller 30 and the pinch roller 31, the platen 39, the paper discharge roller 40 and the spur 4 in the paper transport direction.
1 are sequentially provided. PE sensor 3
5 and the ASF sensor 36 are provided on an electric board 37, and the PE sensor 35 and the ASF sensor 36
The output of each is a control unit (not shown in detail) which will be described later.
Supplied to In the LF roller nip portion, the friction coefficient of one of the LF roller 30 and the pinch roller 31 is set to be high, so that the correction of the sheet traveling direction can be performed effectively.

The PE lever 34 has a rotation shaft substantially at the center of the lever, and one end of the lever is pushed by the leading end of the paper conveyed by the paper feed roller 11 of the automatic paper feeder. Rotate by a predetermined angle. PE lever 34
Is arranged so as to cover the light receiving surface of the PE sensor 35 in the initial position (the state in which the lever does not rotate). When the PE lever 34 rotates by a predetermined angle, the PE lever 34 The position of the other end is shifted from the light receiving surface of the PE sensor 35, and the light receiving surface of the PE sensor 35 is exposed. According to this configuration, the control unit controls the PE sensor 35
Is detected, it is possible to detect that the leading end of the paper conveyed by the paper feed roller 11 of the automatic paper feeder has passed the position of the PE lever 34.

The paper passing through the PE lever 34 enters the LF roller nip, and is conveyed onto the platen 39 at the LF roller nip. A recording head (not shown) is provided at a position facing the platen 39, and the recording head performs recording on the sheet conveyed onto the platen 39. The sheet that has passed over the platen 39 enters a paper discharge unit, and is discharged from the paper discharge unit to the outside of the recording apparatus. The transporting operation by the LF roller nip, the recording by the recording head, and the paper discharging operation by the paper discharging unit are all controlled by the control unit.

The paper feed roller 11 is provided with a light blocking member 36a that covers the light receiving surface of the ASF sensor 36 at a predetermined rotation position. The light-shielding member 36a rotates together with the sheet feeding roller 11, and the light-shielding member 36a comes off the light receiving surface of the ASF sensor 36 at a position where the sheet feeding roller 11 is rotated from a predetermined rotation position to a certain angle. Exposed. The paper feed roller 11 has an area (distance LR) in which paper can be transported, and paper is not transported outside this area. The timing at which the leading area of the area in which the paper can be transported comes into contact with the paper, that is, the paper transport start timing, and the timing at which the light receiving surface of the ASF sensor 36 is exposed coincide with each other.
By detecting the OFF state, the sheet feed roller 11 of the automatic sheet feeder is detected.
Can be detected.

FIG. 4 shows functional blocks of the recording apparatus of the present embodiment described above. Paper feed motor 105, paper feed motor 10
6. The paper discharge motor 107 is connected to the paper feed roller 11, L
A rotational driving force is applied to the F roller 30 and the paper discharge roller 40.
The drive drivers 102, 103, and 104 are for driving a paper feed motor 105, a paper feed motor 106, and a paper discharge motor 107, respectively.

The recording head 101 is disposed to face the platen 39, and performs recording on a sheet sent from the LF roller nip onto the platen 39. This recording head 1
For 01, a recording head of an ink jet type, a wire dot type, a thermal type, a laser beam type or the like can be used.

The control unit 100 controls the PE sensor 35 and the A sensor
Based on each output of the SF sensor 36, the amount of paper transported by the automatic paper feeder (the amount of rotation of the paper feed roller 11) is calculated, and based on the calculation result, each paper feed motor 105, paper feed motor 106, control of the discharge motor 107 (control of the sheet feeding operation and the sheet re-feeding operation). In addition, the control unit 100 also controls the overall operation of the printing apparatus, such as controlling the printing operation by the printing head 101.

Hereinafter, basic control of the sheet feeding operation by the control unit 100 will be described.

FIG. 5 is a timing chart showing the relationship between the rotation angle of the paper feed roller, the state of paper conveyance by the paper feed roller, and the outputs of the ASF sensor and the PE sensor. FIG.
L1 is the distance from the paper stacking surface 15b to the PE lever 34; L2 is the distance from the PE lever 34 to the LF roller nip formed by the LF roller 30 and the pinch roller 31; The distance, M, is a transport margin. XAP is set between the time when the ASF sensor 36 is turned on and the time when the PE sensor 35 is turned on.
Is the amount of rotation. N indicates the amount from when the ASF sensor 36 is turned on to when the paper feed roller 11 actually starts to convey the paper.

During the paper feeding operation, control is performed to push the leading edge of the paper into the LF roller nip to adjust the traveling direction of the paper.
Then, the transportable distance LR of the paper feed roller 11 is set so that LR = L1 + L2 + L3 + M (1).

In FIG. 5, (a) to (g) show the rotation positions of the sheet feeding roller. These rotational positions (a)
6 to 12 show the states respectively corresponding to (g).
Hereinafter, the basic sheet feeding operation will be specifically described with reference to FIGS.

At the rotation position (a) shown in FIG. 5, as shown in FIG. 6, the paper 20 is loaded on the paper loading surface 15b and is in a standby state. At this time, the ASF sensor 3
The light receiving surface 6 is covered by a light blocking member 36, the light receiving surface of the PE sensor 35 is covered by the end of the PE lever 34, and all the sensors are off (= light blocking state).

When a paper feed control signal is sent from the control unit 100 to the drive driver 102, the paper feed motor 105 is driven, and the paper feed roller 11 starts rotating in the direction of arrow A in FIG. When the rotation position of the paper feed roller 11 reaches the position shown in FIG. 5B, as shown in FIG.
The ASF sensor 3 is completely removed from the light receiving surface of the F sensor 36.
6 turns on. At this time, the paper 20 is still loaded on the paper loading surface 15b,
1 has not been transported.

When the ASF sensor 36 is turned on,
The control unit 100 starts calculating how much the paper feed roller 11 has rotated, and the calculation is continuously executed until the leading end of the paper 20 reaches the PE lever 34 and the PE sensor 35 is turned on.

When the paper feed roller 11 further rotates, the platen 1
When the sheet 6 comes into contact with the transportable area of the paper feed roller 11, the transport of the paper 20 is started. When the rotation position of the paper feed roller 11 is the position shown in FIG. 5C, the paper 20 is being conveyed by the paper feed roller 11 as shown in FIG. , The PE sensor 35 is still off.

When the paper feed roller 11 further rotates and the rotational position of the paper feed roller 11 reaches the position shown in FIG. 5D, the leading end of the paper 20 reaches the PE lever 34 as shown in FIG. Then, the PE lever 34 is pushed by the leading end of the paper 20 and rotates. When the PE lever 34 rotates, the end of the PE lever 34 covering the light receiving surface of the PE sensor 35 is completely disengaged from the light receiving surface, and the PE sensor 35 is turned on.

When the PE sensor 35 is turned on, the control unit 100 finishes calculating the rotation amount XAP of the paper feed roller 11, and according to the calculation result, what operation (normal paper feed operation, (Feeding operation). here,
The basic paper feeding operation is described, and it is assumed that no slip occurs between the paper feeding roller 11 and the paper 20. Therefore, the following control of the paper feeding operation by the control unit 100 is performed. Continued.

In order to convey a distance (L2 + L3), which is the sum of the distance L2 from the PE lever 34 to the LF roller nip and the paper pushing amount L3 for adjusting the traveling direction of the paper 20, the paper feed roller 11 is moved in FIG. (D) from the position (d) to the position (e) in FIG. Paper feed roller 11
When the sheet 20 reaches the position shown in FIG. 5E, as shown in FIG. 10, the leading end of the sheet 20 collides with the LF roller nip, and the sheet 20 bends (loops) in the vertical direction in the transport direction.
This is the paper pressing for adjusting the traveling direction of the paper 20, and the amount of deflection (loop) is equal to the paper pressing amount L3.
It is.

After the paper is pushed, the LF roller 30 and the paper feed roller 11 are rotated in synchronization with each other, and the paper 20 is fed to the LF roller nip. When the rotation position of the paper feed roller 11 is the position shown in FIG. 5 (f), as shown in FIG. 9, the paper 20 has been fed halfway into the LF roller nip. In this state, the paper feed roller 11 further rotates, and FIG.
(G), as shown in FIG. 12, the conveyance of the paper 20 by the paper feed roller 11 is completed,
The light receiving surface of the ASF sensor 36 is covered with the light blocking member 36, and the ASF sensor 36 is turned off. Thereafter, the paper feed roller 11 stops at a predetermined position.

The above is a description of the basic paper feeding operation on the assumption that there is no slip between the paper feeding roller 11 and the paper 20 at all.

Normally, in the sheet feeding operation, a slip occurs between the sheet feeding roller 11 and the sheet 20, and due to this slip, the actual position of the sheet becomes the position of the sheet 20 shown in FIGS. The state is offset to the upstream side. In other words, after the ASF sensor 36 is turned on, P
The rotation amount XAP of the paper feed roller 11 until the E sensor 35 is turned on increases as the paper slips. In the case of this example, the allowable amount of only the transport margin M shown in FIG. 5 is set in consideration of the influence of the slip. That is, a normal sheet feeding operation (normal sheet feeding operation) is possible within a range in which the relationship of XAP ≦ N + L1 + M (2) holds.

FIG. 13 shows a flowchart of the normal sheet feeding operation. Here, a description will be given including the recording operation on the supplied paper.

Referring to FIG. 13, first, a paper feed control signal is sent to the driving driver 102 to feed the paper feed roller 11.
Is rotated (step S601). Next, it is confirmed whether or not the ASF sensor 36 has been turned on from off (step S602). This confirmation is performed until it is confirmed that the ASF sensor 36 is turned on. When it is confirmed that the ASF sensor 36 is turned on, it is determined that the paper feed roller 11 has started to rotate, and the PE sensor 35 is turned on from off. It is determined whether or not (step S603).

If it is not confirmed in step S603 that the PE sensor 35 has been turned on from off,
Next, it is determined whether the ASF sensor has been turned on from off (step S604). If it is confirmed that the sheet has been turned off, it is determined that the sheet feeding roller 11 has made one rotation without the sheet being conveyed.
01, and the sheet feeding operation is performed. If the ON state is maintained, the process returns to step S603, and the PE sensor 3
Check if 5 is turned on from off.

If it is confirmed in step S603 that the PE sensor 35 has been turned on from off, the ASF
During a period from when the sensor 36 is turned on to when the PE sensor 35 is turned on, the driving driver 102 supplies the sheet feeding motor 1.
The number of pulses of the drive signal supplied to 05 is counted, and the rotation amount XAP of the paper feed roller 11 is determined based on the counting result (step S605).

When the rotation amount XAP is determined, it is determined whether the determined XAP is equal to or less than the value of (N + L1 + M) (step S606). XAP is (N + L
If the value is equal to or less than (1 + M), the sheet feeding operation is continued as it is, and the process proceeds to the following process. If the value is larger, the process proceeds to the re-feeding sequence (step S607).

When XAP is equal to or smaller than the value of (N + L1 + M), (L2 +
The paper feed roller is rotated by an amount corresponding to the movement amount of L3), and then the paper feed motor is stopped (step S60).
8). As a result, the leading end of the paper 20 abuts on the LF roller nip, and a loop for further adjusting the traveling direction of the paper is formed (step S609).

When the abutment of the sheet on the LF roller nip portion is completed, first, the sheet feeding motor 105 is driven to rotate the sheet feeding roller 11 (step S610).
The paper feed motor 106 is driven to rotate the LF roller 30 (step S611), and a cueing operation for guiding the paper 20 to a recording (for example, printing) start position is performed.

When the cueing operation is completed, a printing operation on the paper 20 is started (step S612). This printing operation is performed based on a printing command supplied from a processing device (for example, a personal computer) outside the recording apparatus. When the printing operation on the paper 20 is completed, it is subsequently checked whether or not there is a next printing command (step S61).
3). If there is a next print command, the above-described step S6
Returning to step 01, the sheet feeding operation for the next sheet is performed, and if the print command has been completed, the sheet feeding operation ends.

In this case, the print command is supplied from an external processing device.
A mechanism for reading information from a recording medium supplied from the outside may be provided, and a print command may be generated in the apparatus based on the read information.

The above is the description of the flowchart at the time of normal paper feeding.

Next, the operation when a slip occurs between the paper feed roller 11 and the paper will be described.

When a slip occurs between the paper feed roller 11 and the sheet, it is necessary to rotate the paper feed roller 11 only once.
The paper pushing amount L3 for adjusting the traveling direction of the paper cannot be secured, or the leading end of the paper does not reach the LF roller nip. In the recording apparatus of the present embodiment, the case where the paper pushing amount L3 cannot be secured and the case where the leading end of the paper is LF
The following different refeeding operations by the control unit 100 are performed depending on whether the sheet does not reach the roller nip.

First, the refeeding operation in the case where the sheet pushing amount L3 for adjusting the sheet traveling direction cannot be secured will be described. Paper pushing amount L into LF roller nip
The condition when 3 cannot be secured can be expressed by the following equation.

N + L1 + M <XAP ≦ N + L1 + L3 + M (3) In the above equation (3), the left term in the equation (3) indicates that the feed roller should be (N + L1) by the time the leading end of the sheet 20 reaches the PE lever 34 from the sheet stacking surface 15b. Where the rotation of the paper feed roller 11 should be performed, the slip between the paper feed roller 11 and the paper 20 causes the paper feed roller 11 to be rotated by (N + L1 + M) by the amount of the set margin M. Means that. The right term is N + L1 + L3 + M, which is the sum of L3 necessary for loop formation.
Means that the paper feed roller 11 must be rotated. Here, N is the ASF sensor 3 as described above.
This is the amount (rotation amount) from when the sheet feeding roller 6 is turned on to when the sheet feeding roller 11 actually starts to convey the sheet 20. During this time, the sheet feeding roller 11 rotates but the sheet 20 is not actually conveyed.

FIG. 14 is a timing chart showing a case where a state occurs in which the paper pushing amount L3 cannot be secured.
FIG. 15 shows a state diagram when the paper pushing amount L3 cannot be secured. Referring to FIG. 14, the slip S occurs immediately after the paper feed roller 11 rotates by the amount of N after the ASF sensor 36 is turned on and the conveyance of the sheet is started. The shortage A is smaller than the required loop formation (= L3). In this case, the transport amount XAP (= N + S + L1) satisfies the condition of the above equation (3).

When the actual loop formation is smaller than the originally required loop formation as described above, it is not possible to secure the paper pushing amount for adjusting the traveling direction of the paper 20, but as shown in FIG. In the state where the paper feed roller 11 is completely rotated, the leading edge of the paper 20 always reaches the LF roller nip. For this reason, when re-feeding the paper, it is only necessary to rotate the paper feed roller 11 again to form a loop so as to obtain only the paper pushing amount L3 for adjusting the traveling direction of the paper 20. Will be. If the transport amount XAP is within the range of the above equation (3),
Make sure that the paper feed roller 11 is completely
Since the leading end of the paper 20 reaches the LF roller nip in the rotated state, the transport amount required for re-feeding is a fixed amount (L3).

In order to carry the paper by a fixed amount (L3), the paper feed roller 11 may be rotated by (N + L3). FIG.
2 shows a state in which refeeding is started and the sheet feeding roller 11 is rotated by (N + L3) to form a loop. By this re-feeding operation, an optimal pushing amount can be given, and a stable re-feeding and correction of the sheet traveling direction can be performed.

After the re-feed operation, the same control as in the above-described normal paper feed operation is performed to perform the sheet cueing and recording (printing) operations.

Next, the refeeding operation when the leading end of the sheet cannot reach the LF roller nip will be described.

The condition when the leading edge of the sheet cannot reach the LF roller nip can be expressed by the following equation.

XAP> N + L1 + L3 + M (4) Here, as described above, N is the amount (rotation amount) from when the ASF sensor 36 is turned on to when the paper feed roller 11 actually starts to convey the paper 20. , During this time the paper feed roller 11
Rotates, but the paper 20 is not actually conveyed.

FIG. 17 shows a timing chart when a state occurs in which the leading end of the sheet cannot reach the LF roller nip, and FIG. 18 shows a state diagram when the leading end of the sheet cannot reach the LF roller nip. Referring to FIG. 17, after the ASF sensor 36 is turned on,
Immediately after the rotation of 1 by N and the conveyance of the sheet is started, the slip S occurs. This slip S is larger than the slip shown in FIG. 14, and therefore, unlike the case of FIG. 14, as shown in FIG. 18, even if the paper feed roller 11 makes one rotation, the leading end of the paper 20 reaches the LF roller nip. do not do.
The transport amount XAP (= N + S + L1) in this case satisfies the condition of the above equation (4).

Since the leading end of the paper 20 does not reach the LF roller nip portion, when re-feeding the paper, the paper feed roller 11 is rotated by adjusting the shortage L3 of the paper feeding amount to the LF roller nip portion. Need to be done. However,
The shortage of conveyance to the LF roller nip varies depending on how far the leading end of the paper 20 has advanced from the PE lever 34.

The amounts of the transport shortage and the loop formation are represented by the following equations.

(Transport shortage) + (Loop formation) = N + (L2 + L3)-(LR-XAP) = N + XAP-L1-M = XAP + K (5) where K = N-L1-M. From the above equation (5),
The length of (transport shortage) + (loop formation) is a variable amount that changes according to the value of XAP, which is the amount of rotation of the paper feed roller 11 from when the ASF sensor 36 turns on to when the PE sensor 35 turns on. It can be seen that it is.

As described above, when re-feeding the paper 20 when the leading end of the paper 20 does not reach the LF roller nip portion, X
By rotating the paper feed roller 11 again by AP + K,
It suffices to convey the shortage of the conveyance and form a loop. FIG. 19 shows a state in which the paper feed roller 11 is rotated by the sum of the shortage of conveyance and the loop formation in re-feeding. By this refeeding operation, an optimum pushing amount can be given, and stable refeeding and correction of the sheet traveling direction can be performed. After this re-feeding operation, the same control as in the above-described normal paper feeding operation is performed to perform sheet cueing and recording (printing) operations.

FIG. 20 is a flowchart showing the above-described re-feed operation. This flowchart corresponds to FIG.
This corresponds to the re-feeding sequence of step S607 executed when "NO" is determined in step S606 of the flowchart shown in FIG.

First, the XAP value calculated and determined in step S605 of FIG. 13 is held (S1301), and a refeed control signal is sent to the drive driver 102 to rotate the feed roller 11 (step S1302). ). Next, AS
It is checked whether the F sensor 36 has been turned on from off (step S1303). This confirmation is ASF sensor 3
6 until it is confirmed that it has been turned on.

When it is confirmed that the ASF sensor 36 has been turned on, subsequently, the X value held in step S1301 is held.
The value of AP is compared with (N + L1 + L3 + M) (S13
04), if the relationship of (XAP> N + L1 + L3 + M) is satisfied, the sheet feeding roller 11 is again rotated by XAP + K, and then the sheet feeding roller is stopped (step S1305).
If not, the paper feed roller is rotated by L3 and the paper feed roller is stopped (step S1306). By this operation, the leading end of the sheet 20 abuts on the LF roller nip, and the formation of a loop for further adjusting the traveling direction of the sheet is completed (step S1307).

When the abutment of the paper 20 against the LF roller nip portion is completed, first, the paper feed motor 105 is driven to rotate the paper feed roller 11 (step S1308), and then the paper feed motor 106 is driven. By rotating the LF roller 30 (step S1309), a cueing operation for guiding the paper 20 to a recording (for example, printing) start position is performed.

When the cueing operation is completed, a recording (for example, printing) operation on the paper 20 is started (step S131).
0). When the recording operation on the paper 20 is completed, it is checked whether or not there is a next print command (step S61).
3). If there is a next print command, the flow returns to step S601 in FIG. 13 to perform the feeding operation of the next sheet. If the print command has been completed, the feeding operation ends.

The above is the description of the flowchart of the sheet re-feeding operation.

In the recording apparatus of the present embodiment described above, the separation section of the automatic sheet feeding apparatus uses a friction separation retard roller system using a torque limiter. However, the gist of the present invention is not limited to this. A friction separation method using a friction pad, a nail separation method using a separation claw, a bank separation method using a resistance of a bank, or the like may be used.

As a method of controlling the operation of the recording apparatus of the present embodiment, a sensor that performs only on / off detection is used.
The gist of the present invention is not limited to this, and the same control can be performed by using a rotary encoder for directly detecting the rotation of the paper feed roller or a non-contact type sensor for accurately detecting the position of the paper. Can be performed.

Further, the paper 20 is not limited to paper, but may be OH
Any sheet material, such as a P (Overhead Projector) sheet, may be used as long as it can be printed.

[0106]

As described above, according to the present invention,
Since the sheet material can always be supplied with the optimal pushing amount, there is an effect that a stable sheet feeding operation and a correcting operation of the sheet advancing direction can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a recording apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing an example of an automatic paper feeder used in the recording apparatus of the present invention.

FIG. 3 is a schematic front view of the automatic sheet feeder shown in FIG.

FIG. 4 is a functional block diagram of the recording apparatus shown in FIG.

FIG. 5 is a timing chart for explaining the operation of the printing apparatus shown in FIG. 1;

FIG. 6 is a schematic partial sectional view for explaining the operation of the recording apparatus shown in FIG.

FIG. 7 is a schematic partial sectional view for explaining the operation of the recording apparatus shown in FIG.

FIG. 8 is a schematic partial cross-sectional view for explaining the operation of the recording apparatus shown in FIG.

FIG. 9 is a schematic partial cross-sectional view for explaining the operation of the recording apparatus shown in FIG.

FIG. 10 is a schematic partial cross-sectional view for explaining the operation of the recording apparatus shown in FIG.

FIG. 11 is a schematic partial sectional view for explaining the operation of the recording apparatus shown in FIG.

FIG. 12 is a schematic partial cross-sectional view for explaining the operation of the recording apparatus shown in FIG.

FIG. 13 is a flowchart for explaining a normal sheet feeding operation of the recording apparatus shown in FIG. 1;

14 is a timing chart illustrating an operation in a case where a state occurs in which the paper pushing amount L3 cannot be secured in the recording apparatus illustrated in FIG. 1;

FIG. 15 is a schematic partial cross-sectional view showing a state when the paper pushing amount L3 of the recording apparatus shown in FIG. 1 cannot be secured.

FIG. 16 is a schematic partial cross-sectional view showing a loop formation state when a refeed operation of a fixed amount is performed in the recording apparatus shown in FIG. 1;

FIG. 17 shows a state in which the leading edge of the sheet is L in the recording apparatus shown in FIG.
FIG. 9 is a timing chart illustrating an operation when a state in which an F roller nip cannot be reached occurs.

FIG. 18 is a schematic partial cross-sectional view showing a state where the leading edge of the sheet of the recording apparatus shown in FIG. 1 cannot reach the LF roller nip.

FIG. 19 is a schematic partial cross-sectional view showing a loop forming state when a refeed operation of a variable amount is performed in the recording apparatus shown in FIG. 1;

FIG. 20 is a flowchart illustrating a refeed operation of the recording apparatus illustrated in FIG. 1;

FIG. 21 is a partial cross-sectional view illustrating a system for conveying a sheet to a recording unit of a conventional recording apparatus including an automatic sheet feeding apparatus in which a sheet feeding roller is controlled by one rotation in one direction.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 paper feed shaft 11 paper feed roller 11 ′ auxiliary roller 12 separation roller 12 b torque limiter 13 return lever 13 a return lever projection 14 return lever control cam 15 ASF base 15 a paper transport reference portion 15 b paper loading surface 16 pressure plate 17 pressure plate spring 18 side guide DESCRIPTION OF SYMBOLS 19 Paper feed roller 20 Paper 26 Separation roller pressing spring 28 Torque limiter holder 30 LF roller 31 Pinch roller 33 Pinch roller holder 34 PE lever 35 PE sensor 36 ASF sensor 36a Light shielding member 37 Electric board 38 Chassis 39 Platen 40 Discharge roller 41 Spur REFERENCE SIGNS LIST 100 control unit 101 recording head 102 to 104 drive driver 105 paper feed motor 106 paper feed motor 107 paper discharge motor 200 paper stacking unit 201 paper 202 paper feed roller 203 LF roller

Continued on the front page F-term (reference) 2C058 AC07 AC12 AD01 AE09 AF04 AF17 AF18 AF31 GA03 GB03 GB31 GB42 GB47 GE24 3F048 AA02 AA05 AB01 BA01 BA21 BB02 CB04 CC02 DA06 DB07 DC13 EA03 EB11 EB21 3F049 AA02 EA03 FB03 EA03 EB03 FC11 FC30 GA02 GB01 GC01 GD01 HA33 JA03 KB02 KB06 LA04 LD10 MA03 MA13 MA15 MA23 MA54 MB03 MC21

Claims (8)

[Claims] A first conveying unit that conveys a printable sheet material; and a second conveying unit that conveys the sheet material conveyed by the first conveying unit by abutting a predetermined pushing amount. Detecting means for detecting a state of sheet material being conveyed by the first conveying means; and detecting a shortage of the amount of sheet material conveyed by the first conveying means based on the sheet material conveyed state detected by the detecting means. Control means for causing the first conveyance means to re-convey the sheet material when the conveyance amount of the sheet material is insufficient, the control means comprising: The recording apparatus according to claim 1, wherein the predetermined amount of press-in is secured by switching between a fixed amount and a variable amount of the first conveyance unit when the first conveyance unit re-conveys the image in accordance with the amount of the shortage. A first conveying unit configured to convey the sheet material by a predetermined conveyance amount in a single conveyance operation, and to leave the sheet material in a free state after the conveyance operation; The control means is configured such that, from the conveyance state of the sheet material detected by the detection means, the tip of the sheet material after the one conveyance operation reaches the second conveyance means in the free state. It is determined whether the state is the first state or the second state that has not reached the second conveying means. In the case of the first state, the first conveying means re-performs the sheet material by a predetermined amount. In the case of the second state, the sheet material is again moved by the first conveying means by an amount obtained by adding the distance from the leading end of the sheet material to the second conveying means to the fixed amount. The recording apparatus according to claim 1, wherein the recording apparatus is transported. . 3. The first conveying means has a roller for conveying the sheet material, and the detecting means is provided at a predetermined position, and detects a passage of a leading end of the sheet material conveyed by the roller. And a second detector for detecting the amount of rotation of the roller from a predetermined rotational position, wherein the controller detects that the first detector detects passage of the leading end of the sheet material. 3. The recording apparatus according to claim 2, wherein the first and second states are determined based on the rotation amount of the roller detected by the second detection unit during the period. 4. The recording apparatus according to claim 3, wherein the first conveying means is configured to complete the conveying operation of the sheet material by rotating the roller once in a predetermined rotation direction. apparatus. 5. The second conveying means includes a pair of rollers, and the pair of rollers is configured such that a friction coefficient of a surface of one roller is larger than a friction coefficient of a surface of the other roller. The recording apparatus according to any one of claims 1 to 4, wherein: 6. A first transporting means for transporting a printable sheet material, and a second transporting means in which a tip of the sheet material transported by the first transporting means is abutted by a predetermined pushing amount and transported. A sheet material conveying method performed in an apparatus having a conveying means, wherein a state of conveyance of the sheet material by the first conveying means is detected, and a shortage of the conveying amount of the sheet material by the first conveying means is detected from the detection result. A first step of determining, and if it is determined in the first step that the transport amount of the sheet material is insufficient, the first transport means causes the transport of the sheet material to be performed again, and A second step of switching the conveyance amount during conveyance between a fixed amount and a variable amount according to the shortage amount of the conveyance amount of the sheet material to secure the predetermined pushing amount. Method 7. The first transporting means is configured such that the sheet material is transported by a predetermined transport amount in one transport operation, and the sheet material is in a free state after the transport operation. In the first step, the leading end of the sheet material after the one-time carrying operation reaches the second carrying means in the free state from the detected carrying state of the sheet material. 1
And a second state in which the second transport means has not been reached. The second step is determined to be the first state in the first step. In the case, the sheet material is conveyed again by a fixed amount by the first conveying means, and when it is determined that the sheet material is in the second state, the second conveying means is moved to the fixed amount from the tip of the sheet material The sheet conveying method according to claim 6, further comprising the step of conveying the sheet again by the first conveying means by an amount obtained by adding the distance to the sheet. 8. The sheet conveyance state detected in the first step, wherein the roller until the leading end of the sheet conveyed by the roller constituting the first conveyance means passes through a predetermined position. 8. The sheet conveying method according to claim 7, wherein a rotation amount from a predetermined rotation position is detected, and the first and second states are determined based on the detected rotation amount.