JP4319781B2 - Paper feeding device and printing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper feeding device and a printing device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a printing apparatus such as a serial impact printer is provided with a paper feeding device, a print head, and the like, and a sheet as a recording medium fed by the paper feeding device is sent to a printing position. By the way, skew may occur in the paper fed by the paper feeding device. Therefore, the generated skew can be corrected.
[0003]
2 is a perspective view showing a main part of a conventional printing apparatus, FIG. 3 is a schematic view of the conventional printing apparatus, FIG. 4 is an enlarged view of a conventional skew correction roller, and FIG. 5 is a flowchart showing the operation of the conventional printing apparatus. It is.
[0004]
As shown in FIGS. 2 and 3, when the operator places and sets the paper 11 on the table 13 so as to be placed on at least one of the plurality of rollers 12a to 12e constituting the skew correction roller 12, the table The table sensor 14 disposed at the lower part of the head 13 detects that the paper 11 has been set, and sends a detection signal to a control unit (not shown). When the detection signal is sent, the control unit drives the skew correction motor 15. A first pulley 16 is attached to a drive shaft (not shown) of the skew correction motor 15, and a second pulley 18 is attached to one end of the skew correction roller 12, and the first pulley 16, 18 is connected between the first pulley 16 and the first pulley 18. A belt 17 is stretched. Therefore, by driving the skew correction motor 15, the skew correction roller 12 can be rotated and the paper 11 can be conveyed.
[0005]
A pair of feed rollers 19 and 20 are disposed in contact with each other on the downstream side of the skew correction roller 12 in the conveyance direction of the paper 11. The feed roller 19 includes a plurality of rollers 19a to 19e, and the feed roller 20 includes a plurality of rollers 20a to 20e. The rollers 12a to 12e, the rollers 19a to 19e, and the rollers 20a to 20e are disposed at positions corresponding to each other in the axial direction.
[0006]
When skew occurs, the front end of the sheet 11 is a predetermined one of the rollers 19a to 19e and 20a to 20e constituting the feed rollers 19 and 20 as the sheet 11 is conveyed. It hits the contact point of 19a, 20a. At this time, since the rollers 19a and 20a and the roller 12a are disposed at corresponding positions in the axial direction, as the front end of the sheet 11 hits the contact point of the rollers 19a and 20a, the sheet 11 is thereafter processed. On the other hand, the roller 12a is caused to slip, and the sheet 11 is not conveyed by the roller 12a.
[0007]
Since the other rollers 12b to 12e continue to convey the paper 11, the front end of the paper 11 sequentially hits the contact points of the rollers 19a to 19e and 20a to 20e, and the roller 12b against the paper 11. .About.12e are slipped, and the paper 11 is no longer conveyed by the rollers 12b.about.12e.
[0008]
In this way, the generated skew is corrected. Note that the skew correction roller 12 is formed of a flexible rubber material so that the rollers 12a to 12e are sufficiently slipped with respect to the paper 11.
[0009]
When the skew correction roller 12 is rotated by a predetermined amount, the control unit sends a drive signal to a line feed motor (hereinafter referred to as “LF motor”) 22 to drive the LF motor 22.
[0010]
By the way, a print head 21 is disposed opposite to the platen 21a downstream of the feed rollers 19 and 20 in the conveyance direction of the paper 11, and a pair of feed rollers 25 and 28 are disposed further downstream of the print head 21. The LF motor 22 is disposed below the print head 21. A third pulley 23 attached to one end of a drive shaft (not shown) of the LF motor 22, a fourth pulley 26 attached to one end of the feed roller 19, and one end of the feed roller 25. A second belt 24 is stretched around the fifth pulley 27. A printing process is performed at a printing position between the print head 21 and the platen 21a.
[0011]
Therefore, when the LF motor 22 is driven, the second belt 24 is caused to travel and the paper 11 is sent to the printing position. The skew correction motor 15 and the LF motor 22 are driven in synchronization, and the skew correction roller 12 and the feed rollers 19, 20, 25, and 28 are rotated in synchronization.
[0012]
After the printing process is performed in this way, the paper 11 is discharged to the back of the printing apparatus by the feed rollers 25 and 28. Subsequently, the drive of the skew correction motor 15 and the LF motor 22 is stopped, and the skew correction roller 12 and the feed rollers 19, 20, 25, and 28 are stopped. In a printing apparatus that discharges the paper 11 to the front (right side in FIG. 3), after the printing process is performed, the skew correction roller 12 and the feed rollers 19, 20, 25, and 28 are in the reverse direction. Driven.
[0013]
Next, a flowchart will be described.
Step S1: Wait for the paper 11 to be set.
Step S2: The skew correction motor 15 is driven.
Step S3 The front end of the paper 11 hits the feed rollers 19 and 20.
Step S4: The skew correction roller 12 is slipped.
Step S5: The LF motor 22 is driven.
Step S6 Print processing is performed.
Step S7 The paper 11 is discharged.
Step S8: Stop driving the skew correction motor 15 and the LF motor 22, and return to Step S1.
[0014]
[Problems to be solved by the invention]
However, in the conventional printing apparatus, it is necessary to make the conveyance speed of the paper 11 by the skew correction roller 12 equal to the conveyance speed of the paper 11 by the feed rollers 19, 20, 25, and 28. 20, 25, and 28 are formed of a rigid body, and the conveyance speed can be made constant, whereas the skew correction roller 12 is made of a flexible rubber material, so that the conveyance speed of the paper 11 is made constant. I can't.
[0015]
Therefore, the skew correction roller 12 tries to rotate the feed rollers 19, 20, 25, 28 excessively or becomes a load against the rotation of the feed rollers 19, 20, 25, 28. As a result, line feed accuracy is reduced and jamming occurs.
[0016]
In addition, since the skew correction roller 12 is formed of a rubber material, in a printing apparatus that discharges the paper 11 to the front, the ink attached to the paper 11 as the printing process is performed is skew correction roller 12. The paper 11 that is transferred to the next and set for the next printing is soiled.
[0017]
Note that ribs 29 are formed by extending radially at four locations in the circumferential direction of the skew correction roller 12.
[0018]
The present invention solves the problems of the conventional printing apparatus, can make the conveyance speed constant, can improve line feed accuracy, and can prevent jamming. And a printing apparatus.
[0019]
[Means for Solving the Problems]
Therefore, in the paper feeding device of the present invention, a conveyance path for conveying the recording medium, a first surface that is disposed facing the conveyance path and does not contribute to the conveyance of the recording medium, and the recording medium A rotating body having a second surface that contributes to conveyance, a first driving unit that rotates the rotating body, and a pair of feed rollers disposed downstream of the rotating body in the conveyance direction of the recording medium; The recording medium in a state in which the second drive means for rotating the feed roller and the upstream end of the second surface in the conveyance direction of the recording medium enter the paper route of the conveyance path. When the front end abuts against the rotating body and is set in the conveyance path, the second surface enters the paper route by driving the first driving means and rotating the rotating body. In a state where the recording medium is passed through the second surface. A skew correction processing means for correcting the skew by abutting the recording medium against the feed roller, and a conveyance processing means for driving the second driving means to rotate the feed roller to convey the recording medium. And have.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0021]
FIG. 1 is an enlarged view of a skew correction roller according to the first embodiment of the present invention, and FIG. 6 is a schematic view of a printing apparatus according to the first embodiment of the present invention.
[0022]
In the figure, 10 is a paper guide, 11 is a paper as a recording medium, and 13 is a table. The paper guide 10 is disposed above the table 13, and the paper 11 is provided between the paper guide 10 and the table 13. A sheet route 33 is formed as a conveyance path for guiding and conveying the sheet. Reference numeral 32 denotes a skew correction roller as a rotating body disposed so as to face the paper route 33, and the skew correction roller 32 includes a plurality of rollers disposed at a predetermined pitch in the axial direction. The table 13 includes a curved portion 13 a that protrudes downward at a portion corresponding to the skew correction roller 32.
[0023]
A table sensor 14 is disposed below the table 13, and the table sensor 14 detects that the paper 11 is set and sends a detection signal to a control unit (not shown). A skew correction motor 15 as a first driving unit is disposed below the skew correction roller 32, and a first pulley 16 is attached to a drive shaft (not shown) of the skew correction motor 15. A second pulley 18 is attached to one end, and a first belt 17 is stretched between the first and second pulleys 15 and 18. Therefore, by driving the skew correction motor 15, the skew correction roller 32 can be rotated and the paper 11 can be conveyed.
[0024]
A pair of feed rollers 19 and 20 are disposed in contact with each other on the downstream side of the skew correction roller 12 in the conveyance direction of the paper 11. The feed rollers 19 and 20 are each composed of a plurality of rollers arranged at a predetermined pitch in the axial direction. The rollers constituting the skew correction roller 32, the rollers constituting the feed roller 19, and the rollers constituting the feed roller 20 are disposed in correspondence with each other in the axial direction.
[0025]
A print head 21 is disposed downstream of the feed rollers 19 and 20 in the conveyance direction of the paper 11 so as to face the platen 21a, and a pair of feed rollers 25 and 28 are disposed further downstream of the print head 21. Then, an LF motor 22 as a second driving unit is disposed below the print head 21. A third pulley 23 attached to one end of the drive shaft of the LF motor 22, a fourth pulley 26 attached to one end of the feed roller 19, and a fifth pulley attached to one end of the feed roller 25. The second belt 24 is stretched around the pulley 27. A printing process is performed at a printing position between the print head 21 and the platen 21a.
[0026]
A predetermined portion in the circumferential direction of the skew correction roller 32 is cut out, and a flat portion 32a as a first surface that does not contribute to the conveyance of the paper 11 and a first portion that contributes to the conveyance of the paper 11 are formed on the outer periphery. A fan-shaped portion 32b is formed as a second surface. Then, when the skew correction roller 32 is rotated and the flat portion 32a is placed on the lower side and the fan-like portion 32b is placed on the upper side, as shown in FIG. 1, the paper route 33 is completely opened, and the flat portion 32a. Is placed on the upper side and the fan-shaped portion 32b is placed on the lower side, the paper route 33 is completely closed. The broken line represents the locus of the fan-shaped portion 32b when the skew correction roller 32 is rotated. X is a roller shape parameter representing the shape of the skew correction roller 32, and the roller shape parameter X is a value of the maximum thickness of the predetermined portion. Y is the route width of the paper route 33. The roller shape parameter X is made larger than the root width Y. Further, the diameter of the skew correction roller 32 is set such that the circumferential length of the fan-shaped portion 32b is longer than the distance La between the skew correction roller 32 and the contact point between the feed rollers 19 and 20. For example, when the diameter of the skew correction roller 32 is about 20 [mm], about 1/3 to 1/4 of the diameter is cut out in the radial direction. In this case, the distance La is set to 20 to 40 [mm]. The skew correction motor 15, the feed rollers 19 and 20, the LF motor 22, the skew correction roller 32, the paper route 33, the control unit, and the like constitute a paper feeding device.
[0027]
Next, the operation of the printing apparatus having the above configuration will be described.
[0028]
FIG. 7 is a first diagram showing the position in the rotation direction of the skew correction roller in the first embodiment of the present invention, and FIG. 8 shows the position in the rotation direction of the skew correction roller in the first embodiment of the present invention. FIG. 9 is a third view showing the position of the skew correction roller in the rotational direction according to the first embodiment of the present invention. FIG. 10 is a diagram of the printing apparatus according to the first embodiment of the present invention. It is a flowchart which shows operation | movement.
[0029]
First, in a state of waiting for the paper 11 to be set (hereinafter referred to as “standby state”), the initial state setting processing unit of the control unit drives the skew correction motor 15 to move the skew correction roller 32. It is placed at the initial position in the rotational direction shown in FIG. At the initial position, the flat portion 32a is inclined, the upstream end e1 in the transport direction of the paper 11 enters the paper route 33, and the downstream end e2 is made higher than the end e1. The paper is routed from the paper route 33. Then, when the operator inserts the paper 11 into the paper route 33 in order to set the paper 11, the front end (left end in the figure) of the paper 11 is abutted near the end e1 of the fan-shaped portion 32b.
[0030]
Thus, when the paper 11 is set, the table sensor 14 detects that the paper 11 has been set, and sends a detection signal to the control unit. The skew correction processing means of the control unit drives the skew correction motor 15 when the detection signal is sent. Then, as the skew correction roller 32 is rotated, as shown in FIG. 8, the sheet 11 is moved along the curved portion 13a via the fan-shaped portion 32b, and the front end is moved to the feed rollers 19 and 20. bump into.
[0031]
When the skew is generated, the sheet 11 hits a contact point of a predetermined roller among the rollers constituting the feed rollers 19 and 20 as the sheet 11 is conveyed. At this time, since the predetermined rollers of the feed rollers 19 and 20 and the corresponding rollers of the skew correction roller 32 are disposed at corresponding positions in the axial direction, the sheet 11 is fed to the predetermined rollers of the feed rollers 19 and 20. Thereafter, the roller corresponding to the skew correction roller 32 is slipped with respect to the sheet 11 in the fan-shaped portion 32b, and the sheet 11 is conveyed by the corresponding roller of the skew correction roller 32. I will not.
[0032]
Since the other rollers of the skew correction roller 32 continue to convey the paper 11 thereafter, the paper 11 sequentially hits the contact points of the other rollers of the feed rollers 19 and 20, and the skew correction roller 32 responds. The other rollers are slipped with respect to the paper 11 in the fan-shaped portion 32b, and the paper 11 is not conveyed by the other rollers.
[0033]
In this way, the generated skew is corrected. The skew correction roller 32 is formed of a flexible material, for example, a rubber material so that each roller can be sufficiently slipped with respect to the paper 11.
[0034]
While the skew correction is being performed, the skew correction motor 15 and the LF motor 22 are driven in synchronization, and the skew correction roller 32 and the feed rollers 19, 20, 25, and 28 are rotated in synchronization.
[0035]
The skew correction roller 32 continues to rotate until the fan-shaped portion 32b is finished. Finally, as shown in FIG. 9, the skew correction roller 32 has the flat portion 32 a directed directly below, the flat portion 32 a and the conveyance direction of the paper 11 are parallel, and the fan-shaped portion 32 b is the paper route 33. And is placed at a position in the rotational direction, that is, at a retracted position and stopped.
[0036]
Subsequently, the conveyance processing means of the control unit drives the LF motor 22, rotates the feed rollers 19, 20, 25, and 28, starts conveying the paper 11, and drives the print head 21 to perform the printing process. Do. During this time, the fan-shaped portion 32 b is retracted from the paper route 33.
[0037]
Next, in the case of a type of printing apparatus that discharges the paper 11 to the back (left side in FIG. 6) when the printing process is completed, the initial state setting is performed as the paper 11 is discharged from the back of the printing apparatus. The processing means immediately rotates the skew correction roller 32 and places it at the initial position. In the case of a type of printing apparatus that discharges the paper 11 to the front (right side in FIG. 6), the operator takes out the paper 11 and the initial state setting process as the paper 11 is no longer detected by the table sensor 14. The means rotates the skew correction roller 32 and puts it at the initial position. Subsequently, the drive of the skew correction motor 15 and the LF motor 22 is stopped, and the skew correction roller 12 and the feed rollers 19, 20, 25, and 28 are stopped.
[0038]
The series of operations of the skew correction roller 32 is set based on the positional relationship between the skew correction roller 32 and the feed rollers 19 and 20, and is performed while the skew correction roller 32 rotates once.
[0039]
As described above, in the present embodiment, the flat portion 32a is formed in a part of the skew correction roller 32, and the printing process is started, and the paper 11 is conveyed by the feed rollers 19, 20, 25, and 28. The fan-shaped portion 32b is retracted during the time, and the conveyance speed can be made constant.
[0040]
Therefore, the skew correction roller 32 does not attempt to rotate the feed rollers 19, 20, 25, 28 excessively or become a load with respect to the rotation of the feed rollers 19, 20, 25, 28. Not only can the line feed accuracy be increased, but also jamming can be prevented.
[0041]
Further, in a printing apparatus that discharges the paper 11 forward, the ink attached to the paper 11 is not transferred to the skew correction roller 32 as the printing process is performed. Thus, the paper 11 set in is not soiled.
[0042]
Furthermore, since the skew correction is performed by rotating the skew correction roller 32 once, the time until the printing is started can be shortened.
[0043]
Next, a flowchart will be described.
Step S11 Wait for the paper 11 to be set.
Step S12: The skew correction motor 15 is driven.
Step S13 The front end of the sheet 11 hits the feed rollers 19 and 20.
Step S14: The skew correction roller 32 is slipped.
Step S15: The drive of the skew correction motor 15 is stopped.
Step S16: The LF motor 22 is rotated.
Step S17 Print processing is performed.
Step S18 The paper 11 is discharged.
Step S19: The skew correction roller 32 is placed at the initial position.
Step S20 The drive of the skew correction motor 15 and the LF motor 22 is stopped, and the process returns to Step S11.
[0044]
Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol.
[0045]
FIG. 11 is a schematic diagram of a printing apparatus according to the second embodiment of the present invention.
[0046]
In this case, as shown in the drawing, a one-way pulley having a built-in one-way clutch (not shown) is used as the second pulley 35 attached to one end of a skew correction roller 32 as a rotating body. The second pulley 35 is rotated in a direction in which the skew correction motor 15 as the first driving unit is driven and the skew correction roller 32 abuts the paper 11 as the recording medium against the feed rollers 19 and 20. When the paper 11 is pulled out from the feed rollers 19 and 20 while the skew correction motor 15 is stopped, the shaft of the skew correction roller 32 is not loaded in the one-way clutch due to the frictional load between the skew correction roller 32 and the paper 11. Is idle.
[0047]
Further, a sensor disk 37 is disposed coaxially with the skew correction roller 32, and a position sensor 36 is disposed opposite to the sensor disk 37. Therefore, the position detection processing means of the control unit (not shown) can detect the initial position, retracted position, etc. of the skew correction roller 32 based on the sensor output of the position sensor 36.
[0048]
Next, the operation of the printing apparatus having the above configuration will be described.
[0049]
FIG. 12 is a first diagram showing the position in the rotation direction of the skew correction roller in the second embodiment of the present invention, and FIG. 13 shows the position in the rotation direction of the skew correction roller in the second embodiment of the present invention. FIG. 14 is a third view showing the position of the skew correction roller in the rotation direction according to the second embodiment of the present invention, and FIG. 15 is a skew correction roller according to the second embodiment of the present invention. FIG. 16 shows a position in the rotational direction of the skew correction roller in the second embodiment of the present invention, and FIG. 17 shows a second embodiment of the present invention. 6 is a flowchart showing the operation of the printing apparatus in the embodiment.
[0050]
First, in the standby state, the initial state setting processing means of the control unit drives the skew correction motor 15 to place the skew correction roller 32 at the initial position shown in FIG.
[0051]
When the paper 11 is set, the skew correction processing means of the control unit drives the skew correction motor 15 to rotate the skew correction roller 32 so that the front end of the paper 11 abuts against the feed rollers 19 and 20. Thereafter, the skew correction roller 32 is caused to slip with respect to the paper 11 at the fan-shaped portion 32b as the second surface, and the generated skew is corrected. Then, as shown in FIG. 15, the controller stops driving the skew correction motor 15 immediately before the last part e <b> 3 of the fan-shaped part 32 b is separated from the paper 11. As a result, the skew correction roller 32 is stopped.
[0052]
At this time, the sheet 11 is not released from the skew correction roller 32 and remains pressed by the skew correction roller 32. Thereafter, the conveyance processing means of the control unit drives the LF motor 22 to rotate the feed rollers 19, 20, 25, and 28 to start conveyance of the paper 11 and start the printing process. Is rotated while the feed rollers 19, 20, 25, and 28 are rotated (followed by the paper 11), and finally the fan-shaped portion 32 b is moved from the paper 11 as shown in FIG. 15. Stops at a position in the direction of rotation that deviates.
[0053]
Then, immediately after the printing process is completed, as shown in FIG. 16, the skew correction roller 32 is rotated and placed at the retracted position. Although the state shown in FIG. 15 differs somewhat depending on the material of the paper 11, the skew correction roller 32 can be accurately stopped at the predetermined position shown in FIG. 15 based on the sensor output of the position sensor 36. Thereafter, the sheet 11 is discharged as in the first embodiment, and the initial state setting processing means places the skew correction roller 32 at the initial position shown in FIG. Subsequently, the drive of the skew correction motor 15 and the LF motor 22 is stopped, and the skew correction roller 12 and the feed rollers 19, 20, 25, and 28 are stopped.
[0054]
As described above, in the present embodiment, after the skew is corrected, the skew correction roller 32 is held in a pressed state without opening the paper 11, so that the stiff paper 11 bounces forward. Or when the rotation of the feed rollers 19 and 20 is started, the paper 11 does not slide with respect to the table 13. Therefore, it is possible to prevent a skew correction error from occurring.
[0055]
Next, a flowchart will be described.
Step S21 Wait for the paper 11 to be set. If the paper 11 is set, the process proceeds to step S22.
Step S22: The skew correction motor 15 is driven.
Step S23 The front end of the paper 11 comes into contact with the feed rollers 19 and 20.
Step S24: The skew correction roller 32 is slipped.
Step S25: The skew correction roller 32 is stopped.
Step S26: The LF motor 22 is driven.
Step S27 Print processing is performed.
Step S28 Wait for the sheet 11 to be removed from the skew correction roller 32.
Step S29: The skew correction roller 32 is placed at the retracted position.
Step S30: The skew correction roller 32 is stopped.
Step S31 The paper 11 is discharged.
Step S32: The skew correction roller 32 is placed at the stop position.
Step S33: The drive of the skew correction motor 15 and the LF motor 22 is stopped, and the process returns to Step S21.
[0056]
Next, a third embodiment of the present invention will be described.
[0057]
FIG. 18 is a perspective view of a skew correction roller according to the third embodiment of the present invention, and FIG. 19 is a cross-sectional view of the skew correction roller according to the third embodiment of the present invention.
[0058]
As shown in the figure, the skew correction roller 42 as a rotating body includes a plurality of rollers 43 arranged in the axial direction, and a shaft 45 is press-fitted into a boss 44 of each roller 43. The boss 44 becomes substantially rigid when the shaft 45 is press-fitted. Between the boss 44 and the outer ring 47, ribs 46a to 46d are formed on a tangent line extending from the boss 44 in a direction opposite to the rotation direction of the skew correction roller 42 at a plurality of locations in the circumferential direction. In this case, the flat portion as the first surface that does not contribute to the conveyance of the sheet 11 is configured by the rib 46 a, and the fan-shaped portion as the second surface that contributes to the conveyance of the sheet 11 is configured by the outer ring 47. The ribs 46a to 46d and the outer ring 47 are made of a flexible material such as a rubber material.
[0059]
Next, the operation of the printing apparatus having the above configuration will be described.
[0060]
20 is an explanatory diagram showing the operation of the skew correction roller in the third embodiment of the present invention, FIG. 21 is a diagram showing a first state of the skew correction roller in the third embodiment of the present invention, and FIG. These are figures which show the 2nd state of the skew correction roller in the 3rd Embodiment of this invention.
[0061]
In this case, as shown in FIG. 20, the skew correction roller 42 includes ribs 46 a to 46 d between the boss 44 and the outer ring 47 and is rotated in the arrow A direction.
[0062]
When the skew is corrected for the paper 48 as a thin recording medium having a low stiffness, as shown in FIG. 21, when the shaft 45 rotates, the paper 48 is bent (bent) and the skew correction roller 42 hardly deforms. . Accordingly, a force that restores the deflection of the paper 11 as a recording medium is applied to the skew correction roller 42 as a pressing force, and the frictional force generated based on the pressing force becomes a transport force to transport the paper 11. Is done.
[0063]
Further, when skew is corrected for the thick paper 49 as a thick recording medium, as shown in FIG. 22, when the shaft 45 rotates, a portion e4 where the rib 46a and the outer ring 47 intersect first hits the paper 49. The part e4 is deformed and crushed. A relatively large frictional force is generated between the outer ring 47 and the sheet 49, and a force is applied to the outer ring 47 in a direction opposite to the rotation direction of the shaft 45, so that the outer ring 47 and the rib 46 a are wound around the boss 44. It deforms as follows. After that, the ribs 46b to 46d are sequentially deformed together with the outer ring 47, and when the paper 49 is removed from the skew correction roller 42, the original shape is restored.
[0064]
Thus, in this embodiment, when the skew correction roller 42 corrects the skew of the thick paper 49 having a strong waist, the outer ring 47 and the rib 46a are deformed so as to be wound around the boss 44. When the paper 49 is used, no excessive pressing force is generated. Accordingly, it is possible to prevent an excessive frictional force and an excessive conveyance force from being generated, so that the conveyance speed of the paper 49 can be made constant. As a result, the skew can be corrected under conditions close to those of the thin paper 48 that is weak.
[0065]
In addition, since excessive frictional force is not generated, it is possible to prevent vibration noise from being generated on the paper 49.
[0066]
In the second and third embodiments, the skew is corrected in the serial impact printer, but the skew can be corrected in other types of printing apparatuses.
[0067]
In the third embodiment, the skew correction roller 42 is used only as a skew correction roller, but it can also be used as a feed roller for conveying paper. In this case, an excessive pressing force is not generated when the thick thick paper 49 is conveyed. Accordingly, it is possible to prevent an excessive frictional force and an excessive conveyance force from being generated, so that the sheet can be conveyed under conditions close to those of the thin sheet 48 having a low stiffness.
[0068]
In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.
[0069]
【The invention's effect】
As described above in detail, according to the present invention, in the paper feeding device, the transport path for transporting the recording medium, the second facing the transport path, and not contributing to the transport of the recording medium. A rotating body having a first surface and a second surface contributing to the conveyance of the recording medium, a first driving means for rotating the rotating body, and a downstream side of the rotating body in the recording medium conveyance direction. A pair of feed rollers provided, a second driving means for rotating the feed rollers, and an upstream end of the second surface in the conveyance direction of the recording medium in the sheet route of the conveyance path When the recording medium is set in the transport path with the front end abutting against the rotating body in the state of entering, the first driving means is driven to rotate the rotating body, thereby With the side entering the paper route, A skew correction processing means for correcting the skew by conveying the recording medium through the surface 2 and abutting the recording medium against the feed roller; and driving the second driving means to rotate the feed roller; Conveyance processing means for conveying the recording medium.
[0070]
In this case, the rotating body includes a first surface that does not contribute to the conveyance of the recording medium, and a second surface that contributes to the conveyance of the recording medium. Accordingly, since the second surface is retracted while the recording medium is being conveyed by the feed roller, the conveyance speed of the recording medium can be made constant.
[0071]
As a result, the rotating body does not attempt to rotate the feed roller excessively or become a load with respect to the rotation of the feed roller, so that the line feed accuracy can be increased and jamming occurs. Can be prevented.
[Brief description of the drawings]
FIG. 1 is an enlarged view of a skew correction roller according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a main part of a conventional printing apparatus.
FIG. 3 is a schematic view of a conventional printing apparatus.
FIG. 4 is an enlarged view of a conventional skew correction roller.
FIG. 5 is a flowchart illustrating an operation of a conventional printing apparatus.
FIG. 6 is a schematic diagram of a printing apparatus according to the first embodiment of the present invention.
FIG. 7 is a first diagram illustrating a position in a rotation direction of a skew correction roller according to the first embodiment of the present invention.
FIG. 8 is a second diagram illustrating the position of the skew correction roller in the rotation direction according to the first embodiment of the present invention.
FIG. 9 is a third diagram illustrating the position of the skew correction roller in the rotation direction according to the first embodiment of the invention.
FIG. 10 is a flowchart illustrating an operation of the printing apparatus according to the first embodiment of the present invention.
FIG. 11 is a schematic diagram of a printing apparatus according to a second embodiment of the present invention.
FIG. 12 is a first diagram illustrating a position in a rotation direction of a skew correction roller according to a second embodiment of the present invention.
FIG. 13 is a second diagram showing the position of the skew correction roller in the rotation direction according to the second embodiment of the present invention.
FIG. 14 is a third diagram showing the position of the skew correction roller in the rotation direction according to the second embodiment of the present invention.
FIG. 15 is a fourth diagram showing the position of the skew correction roller in the rotation direction according to the second embodiment of the present invention.
FIG. 16 is a fifth diagram illustrating the position of the skew correction roller in the rotation direction according to the second embodiment of the invention.
FIG. 17 is a flowchart showing the operation of the printing apparatus according to the second embodiment of the present invention.
FIG. 18 is a perspective view of a skew correction roller according to a third embodiment of the present invention.
FIG. 19 is a cross-sectional view of a skew correction roller according to a third embodiment of the present invention.
FIG. 20 is an explanatory diagram showing the operation of the skew correction roller according to the third embodiment of the present invention.
FIG. 21 is a diagram illustrating a first state of the skew correction roller according to the third embodiment of the present invention.
FIG. 22 is a diagram showing a second state of the skew correction roller according to the third embodiment of the present invention.
[Explanation of symbols]
11, 48, 49 paper
15 Deskew motor
19, 20 Feed roller
22 LF motor
32 Deskew roller
32a Flat part
32b Fan
33 Paper route
35 Second pulley
36 Position sensor
42 Deskew roller
44 Boss
46a-46d rib
47 Outer ring

Claims (9)

(A) a conveyance path for conveying the recording medium;
(B) a rotating body that is disposed facing the conveyance path and includes a first surface that does not contribute to the conveyance of the recording medium and a second surface that contributes to the conveyance of the recording medium;
(C) first driving means for rotating the rotating body;
(D) a pair of feed rollers disposed downstream of the rotating body in the conveyance direction of the recording medium;
(E) second drive means for rotating the feed roller;
(F) In a state where the upstream end of the second surface in the recording medium conveyance direction has entered the sheet route of the conveyance path, the recording medium conveys the front end against the rotating body. when it is set in the road, by rotating the pre-Symbol rotary member by driving the first driving means, in a state in which the second surface is entered into the sheet in the root, the second face A skew correction processing means for correcting the skew by transporting the recording medium through and abutting the recording medium against the feed roller ;
(G) A sheet feeding device comprising: a conveyance processing unit that drives the second driving unit to rotate the feed roller to convey the recording medium.   The sheet feeding device according to claim 1, wherein a circumferential length of the second surface is longer than a distance between the rotating body and a contact point of the pair of feed rollers.   The sheet feeding device according to claim 1, wherein after the skew is corrected, the second surface is retracted from the conveyance path while the feed roller is rotated.   2. The sheet feeding according to claim 1, wherein the first driving unit is stopped while the feed roller is rotated, and the rotating body is rotated along with the recording medium conveyed by the rotation of the feed roller. apparatus. (A) a pulley having a built-in one-way clutch is disposed coaxially with the rotating body;
(B) the one-way clutch, the rotation transmitted from the first drive means to said pulley is transmitted to the rotating body, and blocking the transmission of rotation from the rotary member to the pulley,
(C) The sheet feeding device according to claim 4, wherein the position of the rotating body in the rotation direction is detected by a position sensor.   The sheet feeding device according to claim 1, wherein the rotating body includes a boss, an outer ring, and a plurality of ribs formed between the boss and the outer ring.   The sheet feeding device according to claim 6, wherein each of the ribs is formed from the boss toward the outer ring along a tangential direction with respect to the boss.   The sheet feeding device according to claim 7, wherein each of the ribs is formed in a direction opposite to a rotation direction of the rotating body. (A) a sheet feeding device according to any one of claims 1 to 8;
(B) A printing apparatus comprising: an image forming unit that forms an image on a recording medium fed by the paper feeding device.

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