JP3149894B2 - Paper feeder in printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an sheet feeding apparatus in a printer, and more particularly pre-equipped with a skew prevention
The present invention relates to a paper feeding device in a printer .

[0002]

2. Description of the Related Art In a paper feeding apparatus for feeding stacked papers one by one to a printing unit or the like, if a shift occurs in the width direction at an initial stage of paper feeding, the paper is fed obliquely. This causes inconveniences such as wrinkling of paper and paper jam.

To solve such a problem, Japanese Patent Publication No. 58-66
In the device disclosed in Japanese Patent Publication No. 33, the paper fed by a paper feed roller is intercepted by a pair of paper feed rollers rotating in the reverse direction on the lower side in the paper feed direction, and the leading edge of the paper is adjusted by a loop generated at that time. It is like that. This one is
Although it is excellent in that the direction of the paper can be corrected correctly,
On the other hand, the apparatus has a problem that a relatively long time is required for the skew prevention processing.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
It is an object of the present invention to provide a new sheet feeding device capable of reducing the time required for skew prevention.

[0005]

That is, the present invention provides a sheet feeder for achieving the above object, which is used for a cut sheet.
Narrow paper feed roller and paper feed contacting only in the center in the width direction
Place the roller pair at the upper and lower sides of the paper
And a single drive motor for these rollers
Each drive force transmitting means for transmitting the drive force in the paper transport direction
Stage and connect one of these drive power transmission paths.
Paper feed low when the carriage enters the waiting position.
Transmission of drive power to the
Drive force that cuts off the drive force transmission to the paper feed roller
The connection / disconnection mechanism is interposed .

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIGS. 1 and 2 show an embodiment of the present invention applied to a printer. The printer body denoted by reference numeral 1 in the drawing is configured to be able to be placed horizontally and vertically, and FIG.
Is shown in a horizontal state with the lower side.

The printer body 1 has a paper feed tray 10 in which recording sheets S as cut sheets are stacked and placed.
A paper feed roller unit 20 that comes into contact with the recording paper S in the paper feed tray 10 at a central portion in the width direction and separates the recording paper S from the others and feeds them one by one to a paper feed roller 41; Paper feed roller unit 40 including paper feed roller 41 that temporarily stops at the time of paper feeding to adjust the direction of S
A paper discharge roller unit 50 for discharging the recording paper S, which has been subjected to the recording and writing process on the platen 4 onto the stacker 5, in cooperation with the paper feed roller unit 40;
A driving force transmission switching unit 70 is provided which is operated by a part of the control unit 0 and switches the driving force of the motor 71 to either the paper separating roller unit 10 or the paper feed roller unit 40.

The paper feed tray 10 is configured as a fixed edge guide 12 on the left side of the tray body 11 and a movable edge guide 13 slidable on the right side according to the paper size, with one side reference (the left side in the figure in this embodiment). And
At the front end of the tray body 11, a pad holder 14 for pressing the leading end of the recording paper S against the peripheral surface of the paper feed roller 21 is attached in a state of being urged upward by a spring 15.

The paper feed roller unit 20 is composed of a paper feed roller 21 which comes into contact with a central portion in the width direction of the recording paper S and sends it out by frictional force, and a drawer roller 22 arranged on the upper side in the paper feed direction. The paper feed roller shaft 2 is formed so as to have a length of ten and several percent of the paper width and to be able to contact the surface of the recording paper S equally.
5 is assembled in a roller holder 23 which rotates around a fulcrum.

Reference numeral 30 denotes a roller gear for transmitting a rotational driving force in the paper feed direction to the rollers 21 and 22. The roller gear 30 disposed in the roller holder 23 so as to face the paper feed roller 21 has a friction. It is connected to the paper feed roller shaft 25 via a torque limiter composed of a plate 28 and a spring 29 that presses the plate 28.

As shown in FIG. 3, a pinion 31 integral with the roller gear 30 has two planetary gears 33, 33 on a planetary lever 32 that idles on a paper feed roller shaft 25.
When the roller gear 30 rotates, the planetary gear 33 is engaged, and when the roller gear 30 is stopped, the planetary gear 3 comes into contact with the planetary lever 32 to stop.
3 is provided with a claw 34 for overrunning the planetary gear 3 and a projection 36 for pressing the planetary lever 32. When the paper feed roller shaft 25 receives a rotational driving force, the rack 35 shown in FIG. As shown in FIG.
4 engages the planetary gear 33 to transmit the rotational driving force integrated with the roller gear 30 to the paper feed roller 21, and when the rotational driving force to the paper feed roller 25 is cut off, the projection 36 causes the planetary lever 33 to rotate. To rotate the planetary gear 33 to the pinion 3
The idle rotation on the upper side 1 allows the paper feed roller 21 to independently rotate in the paper feed direction.

On the other hand, the roller gear 30 is detachably connected to an extraction roller gear 38 integral with the extraction roller 22 via an intermediate gear 37 rotatably supported in the elongated hole 24 of the roller holder 23. When the feed roller shaft 25 receives the rotational driving force, the intermediate gear 37
The rotation in the paper feed direction is transmitted to the pull-out roller 22 through
When the feed roller shaft 25 stops, the intermediate gear 3
The pull-out roller 22 is configured to break its engagement with the pull-out roller gear 38 to allow the pull-out roller 22 to rotate independently in the paper feed direction.

The paper feed roller unit 40 is composed of a paper feed roller 41 and a driven roller 45. The paper feed roller 41 is driven by a paper feed motor 71 via a driving force transmission switching unit 70 described later. Attached to the shaft 42.

A paper discharge roller unit 5 disposed below the paper feed roller unit 40 with the platen 4 interposed therebetween.
Reference numeral 0 denotes a paper discharge gear 53 that is configured to rotate in conjunction with the paper feed roller 41 via an intermediate gear 51 that meshes with a pinion 44 integrated with the paper feed gear 43, and that meshes with the intermediate gear 51.
The attached shaft 52 is integrally formed of a resin material.

In order to eliminate the need for a deburring step or the like, the shaft 52 has a cross-shaped paper discharge roller 54 as shown in cross section in FIG. The rollers 55 are formed alternately, and each roller 54,
The ridge portion 55 is configured to contact the recording paper S surface alternately. Therefore, as for the cross-sectional shape of these rollers, any other shapes can be used as long as they can be easily divided and released, and have a ridge that alternately comes into contact with the recording paper S surface.

On the other hand, a paper feed roller 21 and a paper feed roller 41
Transmission switching unit 7 for switching and transmitting the driving force to the transmission
Numeral 0 is provided at its home position so that a switching operation can be performed by the carriage 60.

Reference numeral 73 denotes a paper feed motor 71 mounted here.
As shown in FIG. 4A, the gear 73 is urged by a spring 75 and is always located on the left side in the figure. The first intermediate gear 74 meshes with the first intermediate gear 76, and is further configured to transmit a rotational force to the paper feed roller 41 via the paper feed gear 43 meshing with the pinion 77 integrated with the first intermediate gear 76. As shown in FIG.
Is displaced rightward in the figure against the second intermediate gear 78.
The rotation force is transmitted to the feed roller 21 via a pinion 79 that meshes with the internal gear 26 at the end of the feed roller shaft 25.

Reference numeral 80 denotes a cam member for displacing the switching gear 73 rightward in the drawing against the spring 75. The cam member 80 is rotatably supported on the frame 9 about a shaft 82 as a fulcrum. The other end 81 protrudes into the movement area of the carriage 60, rotates while contacting a part of the carriage 60 that has moved to the home position, and the cam surface 83 of the other end 81 makes a pin which is integral with the switching gear 73. The switching gear 73 is displaced rightward in the figure by pressing the surface 74a.

In the drawing, reference numeral 6 denotes a paper detection sensor for detecting the leading end of the recording paper S fed to the paper feed roller 21. Reference numeral 61 denotes, for example, a thermosensitive sensor mounted on the carriage 60. A recording head 62 of a formula indicates a guide bar for guiding the carriage 60 in the longitudinal direction of the platen 4.

Next, the operation of the apparatus configured as described above will be described. In the standby state for recording and writing, the carriage 60 is located at the home position of the printer main body 1 as shown in FIG. In this state, a part of the carriage 60 presses the other end 81 of the cam member 80 in a direction perpendicular to the plane of the paper, rotates it around the shaft 82, and puts the protruding end surface 74a of the pinion 74 on its top surface 85. In this way, the switching gear 73 is displaced rightward in FIG. 2 to mesh with the second intermediate gear 78, and the paper feed motor 71 is rotated via a pinion 79 integrated with the second intermediate gear 78 and the internal gear 26 meshing with the pinion 79. And the feed roller shaft 25 are connected.

When a paper feed command signal is output in this state, the started paper feed motor 71 drives the paper feed roller 21 and the pull-out roller 22 which are linked via the intermediate gear 37.
Is rotated to feed out the uppermost recording paper S placed on the paper feed tray 10 toward the paper feed roller unit 40.

By the way, as described above, these rollers 21 and 22 are configured to contact and feed out only the center portion in the width direction of the recording paper S, and therefore, as shown in FIG. When the recording paper S is sent out in a slanted state for some reason, the recording paper S receiving the feeding force at the center portion in the paper width direction is centered on the left front end portion a that first comes into contact with the paper feed roller 41. Upon receiving a counterclockwise moment, it instantaneously turns in the direction of arrow X in the figure and stops with its leading edge correctly aligned with the axis of the paper feed roller 41.

On the other hand, the paper leading edge detection sensor 6 disposed immediately before the paper transport roller unit 40 detects the leading edge of the fed recording paper S and outputs a detection signal. To operate the carriage motor to start scanning for writing on the carriage 60.

As shown in FIG. 4A, when the carriage 60 starts moving rightward in the figure, the carriage 60 is displaced rightward in the figure by a part of the carriage 60 via the cam member 80. The switching gear 73 is released to the left in the figure by the urging force of the spring 75 at the same time when the pressing by the carriage 60 is released, disengages with the second intermediate gear 78, and pushes the pinion 77 integral with the first intermediate gear 78 to the first. Intermediate gear 76
And the paper feed gear 43 meshing with the pinion 77
Then, the paper feed roller 41 is rotated, and the recording paper S whose orientation is adjusted is sent out to the platen 4 together with the driven roller 42 which rotates while being in contact with the paper feed roller 41.

On the other hand, by this switching, the intermediate gear 51
The paper discharge roller shaft 52 which has started to rotate via the recording paper S has alternately brought the edges of the paper discharge rollers 54 and 55 having different cross-sectional shapes into contact with the recording paper S, and the recording paper S on which recording and writing have been completed. Is discharged onto the stacker 5 to end a series of paper feeding operations.

Although the above is an explanation of one embodiment of the present invention, it goes without saying that the present invention is not limited to this.

In the above embodiment, the skew is prevented between the paper feed roller 21 and the paper feed roller 41. However, the same operation is performed between the paper feed roller 21 and the platen roller. It is also possible to configure so as to perform this.

[0028]

As described above, according to the present invention, the roller at the start end side of the cut sheet is formed as a roller contacting only with the center portion of the cut sheet in the width direction, and the roller is located downstream of the cut sheet in the sheet feeding direction. The rotary driving force is switched and transmitted to the roller located on the side, so that even if the cut-out paper sent by the roller on the leading end becomes skewed for some reason, the feeding force is applied to the center part in the width direction. When this cut sheet comes in contact with the lower roller in the stopped state, it will momentarily rotate around the leading end portion that first comes into contact, and its front edge is equal to the lower roller. By making contact, the posture of the cut sheet can be quickly corrected.

In addition, the paper feed roller and the paper feed roller are driven.
A part of each driving force transmission path for transmitting force
Drive force is transmitted to the paper feed roller by entering the carriage.
On the other hand, paper is fed by the advance of the carriage from the waiting position
A drive force disconnection mechanism that interrupts the transfer of drive force to the rollers
That the carriage enters the waiting position
The transmission of the driving force to the feed roller is turned off,
Then, loosely hold the leading edge of the paper sent here,
Orient the paper in the correct orientation without causing folds, etc.
Paper is fed by the advance of the carriage from the waiting position.
The transmission of the driving force to the rollers is turned off and this is set in a free state,
Enables correct feeding of paper using only paper feed rollers
In addition, these rollers are used to enter and exit the carriage.
By switching and driving one by one using movement,
Motors can be made smaller with smaller printers.
And simplify the driving force transmission mechanism.
be able to.

[Brief description of the drawings]

FIG. 1 is a plan view of an apparatus showing one embodiment of the present invention.

FIG. 2 is a side view showing the same device in cross section.

FIGS. 3A and 3B are diagrams showing each operation of a rotation transmission mechanism provided in a paper feeding unit.

FIGS. 4A and 4B are diagrams showing each operation of a rotation transmission switching unit.

FIGS. 5A and 5B are explanatory diagrams showing respective states of sheet feeding by the above device.

[Explanation of symbols]

 Reference Signs List 10 paper feed tray 21 paper feed roller 22 pull-out roller 25 paper feed roller shaft 30 roller gear 32 planetary lever 35 rack 41 paper feed roller 54, 55 paper discharge roller 60 carriage 70 rotation transmission switching unit 73 switching gear 80 cam member

Claims (1)

(57) [Claims] 1. The width of a cut sheet that is in contact only with the center of the cut sheet in the width direction.
Place the narrow paper feed roller and paper feed roller pair on the upper side in the paper transport direction.
And a lower side with an interval, and each roller is simply
It transmits the driving force in the paper transport direction from one drive motor
Connect the respective driving force transmission means, and
The carriage moves to the waiting position in part of the drive power transmission path.
While the transmission of the driving force to the paper feed roller is interrupted,
When the carriage advances from the waiting position, the paper feed roller
And a driving force disconnecting mechanism for interrupting the transmission of driving force to the sheet feeding device.