JP2002332135A - Paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeding device capable of driving a paper delivering roller and a paper feeding roller by one driving motor and capable of constantly maintaining an optimum attitude of a paper to be fed. SOLUTION: The paper feeding device includes a paper carrying roller driving gear 2, an intermediate gear 8, a main transmission gear 9, a rocking gear 11 having a first gear 11a and a second gear 11b, a paper feeding roller driving gear 12, a subordinate transmission gear 13, and a control part 7 for controlling a rotation direction of the driving motor 6. The control part 7 is structured so as to control the rotation direction of the driving motor 6 for selectively meshing the first gear 11a with the subordinate transmission gear 13 in executing feeding of the paper P, and selectively meshing the second gear 11b with the paper feeding roller driving gear 12 by reversely rotating the driving motor 6 in delivering a carriage of the paper P from the paper feeding roller 21 to the paper carrying roller 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder which can drive a paper feed roller and a paper feed roller by a single drive motor, and which always keeps the paper to be fed in an optimum posture. About.

[0002]

2. Description of the Related Art Generally, in various printers such as a thermal transfer printer, an ink jet printer, and a laser beam printer used as output devices such as a computer, a word processor, and a facsimile, when a desired recording is performed on a sheet, a plurality of sheets are required. A paper feed tray (paper feed cassette) having a separation mechanism in which paper is stored is mounted on the printer body, and the paper stored in this paper feed tray is brought into contact with a paper feed roller that is driven to rotate. By rotating the sheet, the sheet is separated one by one from above by a separation mechanism, and the sheet is conveyed toward the paper feed roller. Then, the sheet is fed by being conveyed with the rotational driving force of the sheet feed roller. The paper can be transported by the paper feed roller by being sandwiched between the paper feed roller and an auxiliary roller disposed so as to be driven and rotatable around the outer peripheral surface of the paper feed roller. .

In other words, the paper feed roller is responsible for transporting the paper from the paper feed tray to the paper feed roller, and the paper transport roller is responsible for the subsequent transport of the paper.

[0004]

However, the conventional paper feeder described above requires two drive motors, one for driving the paper feed roller and the other for driving the paper feed roller. However, there has been a problem that not only is the economic burden large, but also an obstacle to miniaturization and weight reduction in recent years.

In a conventional paper feeder, a paper feed roller and a paper feed roller are driven to rotate in the same direction, and the paper conveyed by the paper feed roller to the paper feed roller is directly taken over by the paper feed roller. If the leading edge of the paper conveyed to the paper feed roller with the rotational driving force of the paper feed roller is not positioned parallel to the axial direction of the paper feed roller, the paper is fed. There is a problem that the so-called oblique feeding occurs in which the leading edge of the paper is conveyed in a state of being inclined with respect to the axial direction of the paper feeding roller orthogonal to the paper feeding direction.

That is, if the paper to be fed cannot always be set to the optimum posture, and if the paper is skewed, the position of the image to be recorded on the paper is formed obliquely, and the recording quality becomes poor. However, there is a problem that the temperature is reduced.

Therefore, there is a demand for a paper feeder that can drive the paper feed roller and the paper feed roller by one drive motor and can always keep the paper to be fed in an optimum posture.

SUMMARY OF THE INVENTION The present invention has been made in view of these points. The paper feed roller and the paper feed roller can be driven by a single drive motor, and the paper to be fed always has an optimum posture. It is an object of the present invention to provide a paper feeding device capable of performing the above-described operations.

[0009]

In order to achieve the above-mentioned object, a paper feeder according to the present invention is characterized in that a rotational driving force of a driving motor is transmitted and a paper for transmitting the rotational driving force to a paper feed roller. A main transmission gear including a feed roller drive gear, an intermediate gear that always meshes with the paper feed roller drive gear, a main gear that always meshes with the intermediate gear, and a sub gear that is formed coaxially with the main gear and rotates integrally with the main gear. An oscillating gear rotatably supported by an oscillating plate rotatably supported coaxially with the main transmission gear, and having a first gear and a second gear always meshing with sub-gears of the main transmission gear, respectively; A sub-transmission gear in which the first gear of the oscillating gear is selectively meshed with driving of the main transmission gear in one rotational direction, and oscillating with driving of the main transmission gear in the other rotational direction. Gi The second gear is selectively meshed with a paper feed roller drive gear that is always meshed with a sub-transmission gear for transmitting the rotational driving force to the paper feed roller. Rotation of the drive motor so that a first meshing state in which the first gear of the first gear meshes with the auxiliary transmission gear and a second meshing state in which the second gear of the swing gear meshes with the feed roller driving gear can be selectively selected. A control unit for controlling the direction, and the control unit controls the rotation direction of the drive motor so that the swing gear is always in the first meshing state when the paper is fed. When the conveyance of the paper is transferred from the paper feed roller to the paper feed roller, the rotation direction of the drive motor is controlled so that the drive motor is rotated in the reverse direction to bring the swing gear into the second meshing state. On the point.

By adopting such a configuration, the paper feed roller and the paper feed roller can be driven by one drive motor, and the paper can be transported from the paper feed roller to the paper feed roller. By controlling the rotation direction of the drive motor so as to rotate the drive motor in the reverse direction to bring the swinging gear into the second meshing state, the rotation direction of the paper feed roller is changed in the reverse direction while the rotation direction of the paper feed roller is maintained. It can be. By the reverse rotation of the paper feed roller, the leading edge of the paper is conveyed in the reverse direction with respect to the paper feeding direction, and the leading edge of the paper is aligned with the paper feed roller at the contact portion between the paper feed roller and the auxiliary roller. Therefore, the paper is conveyed from the paper feed roller to the recording preparation position in the optimum posture by the forward rotation of the paper feed roller thereafter. Therefore, the paper feed roller and the paper feed roller can be driven by one drive motor, and the posture of the paper to be fed can always and easily be kept at the optimum posture.

The reverse rotation of the drive motor by the control unit causes the leading edge of the sheet located at the leading side in the paper feeding direction of the paper fed by the paper feeding roller to the paper feeding roller to slightly exceed the paper feeding roller. It is preferable that the configuration is such that the operation is performed at the point of time in order to always make the posture of the sheet conveyed to the recording preparation position the optimum posture.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIGS. 1 to 4 show an embodiment of a sheet feeding device according to the present invention. FIG. 1 is a front view of a main part, and FIG. 2 is a diagram in which the sheet feeding device shown in FIG. 1 is mounted on a printer frame. FIG. 3 is a front view showing a first meshing state in which a first gear of a swing gear meshes with a sub-transmission gear, and FIG. 4 is a second gear of the swing gear being a feed roller driving gear. It is a front view which shows the 2nd meshing state which meshed with FIG.

As shown in FIG. 1, the paper feeder 1 of the present embodiment has a paper feed roller drive gear 2. An idle gear 3 constantly meshing with the paper feed roller driving gear 2 is rotatably disposed on the left side of the paper feed roller driving gear 2, and is always meshed with the idle gear 3 on the left side of the idle gear 3. The output gear 4 is a rotatable two-stage gear. And on the left side of the output gear 4,
A pinion 5 that always meshes with the output gear 4 is provided. The pinion 5 is fixed to an output shaft 6a of a drive motor 6 composed of a forward / reverse rotatable servo motor or a pulse motor, and the rotational driving force of the drive motor 6 is applied to the pinion 5, the output gear 4 and the idle gear. 3 are transmitted to the paper feed roller drive gear 2 via this order. The drive motor 6 is electrically connected to a control unit 7 described later, and is driven to rotate based on a control command sent from the control unit 7.
Note that, as a configuration for transmitting the rotational driving force of the drive motor 6 to the paper feed roller drive gear 2, the number of gears interposed between the pinion 5 and the roller drive gear 2 is changed depending on the arrangement position of the drive motor 6. The configuration is not particularly limited to the configuration of the present embodiment.

On the right side of the paper feed roller drive gear 2,
An intermediate gear 8 that always meshes with the paper feed roller drive gear 2 is rotatably disposed, and on the right side of the intermediate gear 8,
A main transmission gear 9 is rotatably disposed. The main transmission gear 9 is a two-stage gear having a large-diameter main gear 9a always meshing with the intermediate gear 8, and a small-diameter sub-gear 9b formed coaxially with the main gear 9a and integrally rotating with the main gear 9a. Is formed.

A sub-gear 9b is provided at the tip end of a main transmission gear support shaft 10 which rotatably supports the main transmission gear 9.
A swing gear 11 having a first gear 11a and a second gear 11b, which always meshes with the swing gear 11, is provided. The first gear 11a and the second gear 11b are connected to the main transmission gear support shaft 1
The first gear 11a and the second gear 11b mainly rotate around the outer peripheral surface of the sub-gear 9b with the rotation of the sub-gear 9b. It is formed so as to be able to revolve around the transmission gear support shaft 10.

On the lower right side of the oscillating gear 11, a sub-transmission gear 13 selectively meshing with the first gear 11a is rotatably disposed. The gear 12 is always engaged.

On the upper right side of the oscillating gear 11, a paper feed roller driving gear 1 selectively meshing with the second gear 11b is provided.
2 is rotatably arranged.

The paper feed roller drive gear 2 is fixed to one end of a paper feed roller drive shaft 14a of the paper feed roller 14. As shown in FIG. 2, the paper feed roller drive shaft 14a is rotatably supported at substantially the center of the printer frame 15 by two side plates 15a of the printer frame 15, and an auxiliary roller 16 Are arranged so as to be able to be driven and rotated. Also, printer frame 1
5, a recording head (not shown) is disposed, and can record characters, images, and the like at a predetermined position of the paper P (FIGS. 3 and 4) fed by the paper feed roller 14. It has become. Note that, as the recording head, one according to the type of the printer, for example, a thermal head, a line thermal head, an ink jet head, a print head, or the like is used. Further, the recording head can be arranged on the left side of the paper feed roller 14 or between the paper feed roller 14 and a paper feed roller 21 described later, as required according to a design concept or the like.

The drive motor 6 is fixed to one side plate 15a of the printer frame 15 shown on the front side in FIG. 2, and the outer surface of the side plate 15a rotatably supports the output gear 4 shown in FIG. An output gear support shaft 17, an idle gear support shaft 18 that rotatably supports the idle gear 3,
An intermediate gear support shaft 19 that rotatably supports the intermediate gear 8,
A main transmission gear support shaft 10 that rotatably supports the main transmission gear 9 and the swing gear 11 and a sub transmission gear support shaft 20 that rotatably supports the sub transmission gear 13 are provided with their tips facing outward. Has been established.

The feed roller drive gear 12 is fixed to one end of a feed roller drive shaft 21a of the feed roller 21. The paper feed roller drive shaft 21a is rotatably supported by the side plates 15a of the printer frame 15 near the right end of the printer frame 15 so as to extend in parallel with the paper feed roller 14. Also, the paper feed roller 21
The paper feed roller drive shaft 21a has two roller bodies 21b.
Are fixed at appropriate intervals.

Below the paper feed roller 21, a paper feed tray (paper feed cassette: not shown) provided with a separation mechanism accommodating a plurality of conventionally known sheets P can be mounted. When desired recording is performed on the paper P, the paper feed roller 21 is driven to rotate while the uppermost paper P stored in the paper feed tray is in contact with the roller body 21b from below. Thus, the paper can be separated one by one from above and conveyed toward the paper feed roller 14.

The control section 7 has a CPU and a memory (both not shown) formed of ROM, RAM or the like having an appropriate capacity, and is disposed at a desired position on the printer frame 15. I have. The memory stores at least a sheet feeding program as a control program for controlling sheet feeding operation. In this paper feed program, when the paper P is fed, the first gear 11a of the swing gear 11 shown in FIG. 3 meshes with the auxiliary transmission gear 13, and the swing shown in FIG. The rotation direction of the drive motor 6 is controlled so that the second gear 11b of the gear 11 can be selectively brought into the second meshing state in which the second gear 11b meshes with the paper feed roller drive gear 12. In this paper feed program, when the paper P is fed, the rotation direction of the drive motor 6 is controlled so that the swing gear 11 is always in the first meshing state, and the paper P is fed. Paper roller 21 to paper feed roller 1
For example, a program for controlling the rotation direction of the drive motor 6 such that the drive motor 6 is rotated in the reverse direction so that the swing gear 11 is brought into the second meshing state when the drive motor 6 is transferred to the drive gear 4. At this time, the time of the reverse rotation of the drive motor 6 is set such that the leading edge Pa located on the leading side in the paper feed direction of the paper P fed to the paper feed roller 14 by the paper feed roller 21 is moved as shown in FIG. It is more preferable that the program be executed when the paper feed roller 14 slightly exceeds the left side of the paper feed roller 14 in order to always keep the posture of the paper P to be fed in the optimum posture.

As the paper P, various kinds of paper such as plain paper, cardboard, resin sheet, card and the like can be used.

Next, the operation of this embodiment having the above-described configuration will be described.

According to the paper feeder 1 of the present embodiment, the paper P
When the paper feeding is performed, the rotational driving force of the driving motor 6 driven based on the control command sent from the control unit 7 is:
First, the signal is transmitted to the paper feed roller drive gear 2 attached to one end of the paper feed roller drive shaft 14a via the pinion 5, the output gear 4, and the idle gear 3, and as shown in FIG. The drive motor 6 is rotated in a direction opposite to the rotation direction. That is, when the drive motor 6 is rotated clockwise in FIG. 3 which is one of the rotation directions, the paper feed roller drive gear 2 rotates counterclockwise in FIG.

The rotation of the paper feed roller driving gear 2 in the counterclockwise direction is transmitted to the main gear 9a of the main transmission gear 9 via the intermediate gear 8, and a small-diameter sub gear 9b that rotates integrally with the main gear 9a is illustrated. At 3, rotate counterclockwise. The rotation of the sub-gear 9b in the counterclockwise direction is performed by rotating the first gear 11a and the second gear 11b of the swing gear 11 meshing with the sub-gear 9b together with the outer peripheral surface of the sub-gear 9b around the main transmission gear support shaft 10. The first gear 11a of the oscillating gear 11 is brought into a first meshing state meshed with the sub-transmission gear 13, and the first gear 11a is rotated clockwise in FIG. This first gear 11a
In the clockwise direction rotates the sub-transmission gear 13 in the counterclockwise direction, and rotates the paper feed roller drive gear 12 meshing with the sub-transmission gear 13 in the clockwise direction opposite to the paper feed roller drive gear 2. . As a result, the paper feed roller 21 attached to the paper feed roller drive shaft 21a rotates clockwise in FIG. 3, and the paper P moves from the paper feed roller 21 to the paper feed roller 14 as indicated by an arrow A in FIG. The paper is conveyed along the paper feed direction indicated by.

Next, a sheet P indicated by a broken line in FIG.
When the leading edge Pa located at the top of the paper feed direction slightly exceeds the paper feed roller 14 to the left, a control command to reverse the rotation direction of the drive motor 6 is sent from the control unit 7. The rotational driving force by the reverse rotation of the drive motor 6 is transmitted to the paper feed roller drive gear 2 via the pinion 5, the output gear 4 and the idle gear 3, and as shown in FIG. The drive motor 6 is rotated in a direction opposite to the rotation direction. As a result, the paper feed roller 14 rotates in a direction opposite to the rotation direction of the drive motor 6. That is, when the drive motor 6 is rotated clockwise in FIG. 4, which is the other rotational direction, the paper feed roller 14 and the paper feed roller drive gear 2 are rotated clockwise in FIG.

The clockwise rotation of the paper feed roller driving gear 2 is transmitted to the main gear 9a of the main transmission gear 9 via the intermediate gear 8, and the small-diameter sub gear 9b, which rotates integrally with the main gear 9a, is moved to the position shown in FIG. Rotate clockwise in. The clockwise rotation of the sub gear 9b is controlled by the first gear 11a and the second gear 11a of the swing gear 11 meshing with the sub gear 9b.
The gear 11b revolves clockwise around the main transmission gear support shaft 10 along the outer peripheral surface of the sub-gear 9b,
The second gear 11b of the swing gear 11 is connected to the feed roller driving gear 1
2 is engaged with the second gear 11b, and the second gear 11b
Rotate in the counterclockwise direction at. This second gear 11b
Rotates the sheet feed roller drive gear 12 meshing with the second gear 11b in the same clockwise direction as the paper feed roller drive gear 2.

Therefore, the paper feed roller 14 is driven by the paper P
3 is conveyed in the direction opposite to the paper feed direction as shown by arrow B in FIG. 3, and the paper feed roller 21 moves the rear end side of the paper P as shown by arrow a in FIG. The paper is transported along the paper feed direction. As a result, the leading edge Pa of the sheet P is reversely conveyed to the sheet feeding roller 21 side where the sheet feeding roller 14 and the auxiliary roller 16 are in contact, and the leading edge Pa of the sheet P is 16 is held in a free state at a position opposed to the contact portion with the base member 16. Thereby, the leading edge Pa of the paper P is moved between the paper feed roller 14 and the auxiliary roller 1.
6 is aligned in a straight line along the axial direction of the paper feed roller 14 that is orthogonal to the paper feed direction on the side of the paper feed roller 21 that is in contact with the paper feed roller 6. Will be located in parallel along the axial direction of. That is, the position of the leading edge Pa of the sheet P can be easily corrected.

Next, a sheet P indicated by a broken line in FIG.
When the leading edge Pa of the paper is aligned with the paper feed roller 21 at the contact portion between the paper feed roller 14 and the auxiliary roller 16, the control unit 7 sends a control command to rotate the drive motor 6 in the forward direction. Is done. Then, as described above, the paper feed roller 14 rotates in the counterclockwise direction, and the paper feed roller 21 rotates in the clockwise direction, so that the paper feed roller 21 feeds the paper to the paper feed roller 14 and the paper feed roller 14 And the leading edge Pa of the paper P is
4 again.

As described above, according to the paper feeder 1 of the present embodiment, the paper feed roller 14 and the paper feed roller 21 can be driven by the single drive motor 6, and the paper P is transported by the paper feed roller 21. The drive motor 6 is rotated in the reverse direction to transfer the swing gear 11 to the second
By controlling the rotation direction of the drive motor 6 so as to be in the meshing state, the rotation direction of the paper feed roller 14 can be reversed while keeping the rotation direction of the paper feed roller 21 unchanged. The reverse rotation of the paper feed roller 14 causes the leading edge Pa of the paper P to be conveyed in the reverse direction with respect to the paper feed direction.
Is aligned in a straight line along the axial direction of the paper feed roller 21 perpendicular to the paper feed direction on the side of the paper feed roller 21 at the contact portion with the paper feed roller 21.
The paper P is conveyed from the paper feed roller 14 toward the recording preparation position in an optimal posture.

Therefore, according to the paper feeder 1 of the present embodiment, the paper feed roller 14 and the paper feed roller 21 can be driven by one drive motor 6, and the posture of the paper P to be fed is always optimized. The posture can be easily and reliably set.

Further, according to the paper feeder 1 of the present embodiment,
The reverse rotation of the drive motor 6 by the control unit 7
1, the recording is performed when the leading edge Pa of the sheet P positioned at the leading side of the sheet P conveyed to the sheet feed roller 14 in the sheet feed direction slightly exceeds the sheet feed roller 14. It is possible to easily and more reliably make the posture of the paper P fed to the preparation position always the optimum posture.

The present invention is not limited to the above embodiment, but can be variously modified as needed.

[0036]

As described above, according to the paper feeder of the present invention, the paper feed roller and the paper feed roller can be driven by one drive motor, and the posture of the paper to be fed is always optimized. An extremely excellent effect is achieved such that the posture can be easily and reliably set.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of an embodiment of a sheet feeding device according to the present invention.

FIG. 2 is a perspective view showing a main part in a state where the sheet feeding device of FIG. 1 is mounted on a printer frame.

FIG. 3 is a view similar to FIG. 1 showing a first meshing state in which a first gear of a swing gear of the paper feeding device of FIG. 1 meshes with a sub-transmission gear;

FIG. 4 is a view similar to FIG. 1 showing a second meshing state in which a second gear of a swing gear of the paper feeding device of FIG. 1 meshes with a paper feeding roller driving gear;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feeder 2 Paper feed roller drive gear 6 Drive motor 7 Control part 8 Intermediate gear 9 Main transmission gear 9a Main gear 9b Sub gear 11 Oscillating gear 11a 1st gear 11b 2nd gear 11c Oscillating plate 12 Feeding roller drive Gear 13 Sub-transmission gear 14 Paper feed roller 14a Paper feed roller drive shaft 21 Feed roller 21a Feed roller drive shaft P Paper Pa Leading edge

Claims (2)

[Claims] 1. A paper feed roller drive gear for transmitting a rotational drive force to a paper feed roller to which a rotational drive force of a drive motor is transmitted; an intermediate gear that always meshes with the paper feed roller drive gear; A main transmission gear including a main gear that always meshes with the gear, and a sub-gear formed coaxially with the main gear and integrally rotating with the main gear; and an oscillating plate rotatably supported coaxially with the main transmission gear. A swing gear having a first gear and a second gear, each of which is rotatably supported by the main transmission gear and which always meshes with a sub gear of the main transmission gear; and An auxiliary transmission gear in which a first gear of the oscillating gear is selectively meshed, and a second gear of the oscillating gear selectively meshed with driving of the main transmission gear in the other rotational direction; A feed roller driving gear that always meshes with the sub-transmission gear for transmitting the rotational driving force to the paper roller; and a first gear of the swinging gear is connected to the sub-transmission gear when the paper is fed. A first meshed state in which the second gear of the oscillating gear meshes with the paper feed roller driving gear;
A control unit for controlling the rotation direction of the drive motor so as to be able to selectively take the engaged state, wherein the control unit always performs the swinging when feeding a sheet. The rotation direction of the drive motor is controlled so as to bring the gear into the first meshing state, and when the paper is conveyed from the paper feed roller to the paper feed roller, the drive motor is rotated in the reverse direction to swing the paper. A sheet feeder configured to control a rotation direction of the drive motor so that a gear is brought into a second meshing state. 2. A reverse rotation of the drive motor by the control unit causes a leading edge of a sheet positioned in a leading direction of a sheet fed by the sheet feed roller to the sheet feed roller to move in the sheet feed direction. 2. The sheet feeding apparatus according to claim 1, wherein the sheet feeding is performed at a point slightly beyond the rollers.