JP2003081460A - Sheet feeding device and recording device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding device and a recording device provided with the same capable of returning a sheet against a sheet feeding direction with a simple structure. SOLUTION: A sheet feeding roller 15 is provided above a sheet storing cassette 10 and is retained rotatably on an arm 14 supported rotatably around a fulcrum 14a positioned upstream from the sheet feeding roller 15 in a sheet feeding direction, and under a condition capable of getting close to and part from sheets P stored in the sheet storing cassette 10. The sheet feeding roller 15 gets into contact with an uppermost sheet P1 of sheets P loaded on the sheet feeding cassette 10 by self-weight of the arm 14 and downward rotation force, and is rotated by rotational driving power from a driving power source (not shown in Figure) transmitted via a pulley 16, a belt 17 and a gear 18 in recording an image. A mechanical timer (not shown in Figure) enabling to transmit driving power from the driving power source with designated time delay is constructed between the pulley 16 and the driving power source which is not shown in Figure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus and a recording apparatus including the sheet feeding apparatus.

[0002]

2. Description of the Related Art Conventionally, in a recording device such as a printer, a copying machine or a facsimile, a sheet (for example, paper or a resin film) as a recording medium stored in a sheet storing means is usually fed by a sheet feeding means. It is equipped with a sheet feeding device adapted to send out. Then, the sheet delivered by the sheet supply device is conveyed to the image recording section by the sheet conveying means, and the image is recorded on the sheet in the image recording section. By the way, some means have been devised and implemented for constructing this sheet feeding apparatus. Among them, there is one that obtains the roller pressure at the time of sheet feeding by the weight of the arm that holds the sheet feeding roller rotatably and the force of the downward movement when feeding the sheet.

This structure has a structure different from that of another structure in which a spring force is applied to a sheet supply roller or stacked sheets to press the sheet or the sheet supply roller to obtain a roller pressure at the time of sheet supply. It has the advantage of being simple.

[0004]

However, in the structure in which the roller pressure at the time of sheet feeding is obtained by the weight of the arm holding the sheet feeding roller rotatably and the force of the downward movement, the force of the drive source is applied to the gear train. Is used to convert into the rotational force of the sheet supply roller. The arm is rotatably supported by a fulcrum located upstream of the sheet supply roller in the sheet supply direction. Therefore, when trying to return the sheet in the opposite direction to the sheet feeding direction, the sheet feeding roller does not rotate freely, so that a frictional force is generated between the sheet feeding roller and the sheet, and the sheet feeding roller is rotatably held. There was a problem that the force of downward movement acted against the existing arm unintentionally, the sheet feeding roller bites against the sheet and moves freely, acting in a direction to stop the sheet and unable to return the sheet. .

Therefore, the object of the present invention is made in view of such an actual situation, and a sheet feeding device capable of returning a sheet against a sheet feeding direction with a simple structure, and a recording apparatus having the same. To provide.

[0006]

In order to achieve the above object, the present invention has a sheet supply roller rotatably held and a fulcrum located upstream of the sheet supply roller in the sheet supply direction. A sheet feeding device having a rotatably supported arm and a drive source for rotationally driving the sheet feeding roller, and obtaining a roller pressure for a sheet to be fed by the weight of the arm and a force of a rotating operation. In the above, the delay means for transmitting the rotational driving force from the drive source to the sheet supply roller after delaying it by a predetermined time is provided between the drive source and the sheet supply roller.

In the above sheet feeding device, when the sheet is returned in the direction opposite to the sheet feeding direction, a delay amount equal to or greater than the amount of returning the sheet is accumulated in the delay means prior to the operation of returning the sheet. It is preferable.

A recording device for recording an image on a sheet fed by the sheet feeding device as described above also belongs to the present invention.

In the above-mentioned structure, the delay means for transmitting the rotational driving force from the drive source to the sheet supply roller with a predetermined delay is provided between the drive source and the sheet supply roller. As a result, before returning the sheet against the sheet feeding direction, the drive source is reversely rotated and the delay amount equal to or greater than the sheet returning amount is accumulated in the delay means, so that the sheet when returning the sheet is returned. The frictional force generated between the sheet feeding roller and the sheet feeding roller causes the sheet feeding roller to oppose the sheet feeding direction by the amount of delay accumulated in the delaying unit,
It becomes possible to go around. While the sheet supply roller is rotating around, the arm holding the sheet supply roller rotatably receives a downward motion force against the arm, and the sheet supply roller bites into the sheet and moves freely. It becomes possible to return the seat without any trouble.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of an ink jet printer which is an example of a recording apparatus provided with a sheet feeding apparatus according to an embodiment of the present invention. An inkjet printer 1 shown in this figure has an image recording unit 3A provided with a recording head 3 and a carrier (also called a carriage) 2 on which the recording head 3 is mounted, in an inkjet printer main body (hereinafter referred to as main body) 1A. . Here, the recording head 3 has a plurality of nozzle rows (not shown) on a surface facing a sheet P (for example, paper, resin film, etc.) as a recording medium,
It is configured to eject ink of different colors for each nozzle row. It should be noted that the recording head 3 is provided with ink nozzles 4 for respective color nozzles via respective recording liquid supply tubes 5.
Ink of each color is supplied.

Both ends of the carrier 2 are fixed to the frame 6 of the main body 1A and are slidably supported along a guide shaft 7 and a guide rail 8 which are arranged in parallel with each other. An image is recorded on the sheet by ejecting ink from the recording head 3 toward the sheet P while reciprocating the carrier 2. In addition, carrier 2
Is configured to reciprocate by a belt driving device (not shown) and a motor.

On the other hand, FIG. 2 is a sectional view showing a schematic structure of the ink jet printer 1. In FIG. 2, the sheet feeding device 1B includes a sheet storage cassette 10 which is a sheet storage means detachably attached to the main body 1A, and a sheet feeding means which feeds out the sheet P stored in the sheet storage cassette 10 by a frictional force. A certain sheet supply roller 15 is provided. Here, the sheet storage cassette 10 is provided with a separation plate 19 which is a slope member for abutting the sheet P fed by the rotation of the sheet supply roller 15 and separating the sheet P at the downstream end in the sheet feeding direction. Has been. The sheet supply roller 15 is rotatable above an arm 14 which is provided above the sheet storage cassette 10 and is rotatably supported by a fulcrum 14a located upstream of the sheet supply roller 15 in the sheet feeding direction. And the sheet P stored in the sheet supply cassette 10
It is held so that it can be moved in and out of Then, during image recording, the sheet supply roller 15 applies a desired pressure to the uppermost sheet (front row) of the sheets P stacked in the sheet supply cassette 10 by the weight of the arm 14 and the force of downward rotation. The pulley 1 shown in FIG.
6, the belt 17 and the gear 18 are rotated by a drive from a drive source (not shown) transmitted.

FIG. 4 shows a mechanical timer A which is a delay means formed between the pulley 16 and a drive source (not shown).

Between the pulley 16 and a drive source (not shown),
A mechanical timer A, which is a delay unit that includes a transmission gear (A) 22 and a transmission gear (B) 23, mechanically delays and transmits a driving force from a driving source (for example, a motor) for a predetermined time. There is. Specifically, as shown in FIG. 4, a transmission gear (A) 22 is integrally fixed on a shaft directly or indirectly connected to an output shaft of a drive source (not shown), and a pulley 16 and a pulley 16 are coaxially arranged on the shaft. The connected transmission gear (B) is rotatably inserted. The transmission gears (A) 22 and the transmission gears (B) 23 are respectively provided on the surfaces facing each other.
Members 22a and 23a are provided which come into contact with each other when the 22 rotates in one direction by a predetermined amount (angle). When a sheet is supplied, the contact member 22a of the transmission gear (A) 22 is moved to the transmission gear (B) 2
The contact member 23a of No. 3 is pushed, the transmission gear (B) 23 is rotated, and the pulley 16 is rotated.

Using such a delay means, before the sheet P is returned (back-fed) against the sheet feeding direction, the drive source is reversely rotated so that the sheet P is returned (back-feed amount). A delay amount equal to or greater than the above (a time lag from the operation of the drive source to the start of rotation of the sheet supply roller) is accumulated in the delay means. For example, in the case of the mechanical timer A shown in FIG. 4, the transmission gear (A) 22 is reversely rotated by a predetermined amount in a direction opposite to the rotation direction at the time of sheet supply. This reverse rotation amount is set to be equal to or larger than the rotation amount of the transmission gear (B) 23 when the sheet P is returned in the direction opposite to the sheet feeding direction.

As a result, the sheet P when the sheet P is returned
By the frictional force generated between the sheet feeding roller 15 and the sheet feeding roller 15, the sheet feeding roller 15 can rotate around the sheet in the sheet feeding direction by the amount of delay accumulated in the delay unit.
An arm 14 that rotatably holds the sheet supply roller 15 while the sheet supply roller 15 is rotating.
In addition, the force of the downward movement acts against the intention, and the sheet P can be returned without the sheet supply roller 15 biting into the sheet P and moving freely.

In FIG. 2, reference numeral 9 is a conveying roller, reference numeral 21 is a U-turn roller (reversing roller), reference numeral 2
Reference numeral 0 denotes a roller guide provided at a position facing the U-turn roller 21, and the sheet P1 delivered by the rotation of the sheet supply roller 15 is formed between the U-turn roller 21 and the roller guide 20. Further, the sheet passes through the sheet conveyance path R and is directed toward the conveyance roller 9.

Next, the image recording operation of the ink jet printer having such a structure will be described. When the image recording operation is started, first, the arm 14 is rotated downward and its own weight causes the sheet supply roller 15 to apply a predetermined pressure (a predetermined pressure) to the uppermost (frontmost row) sheet P1 of the sheets P stacked in the sheet supply cassette 10. Contact with roller pressure). Then, when the sheet supply roller 15 rotates in this state, the sheet P is sent out, and thereafter, only the uppermost sheet P1 enters the sheet conveyance path R due to the resistance force of the separation plate 19. At this time, in order to stabilize the separation performance, the outer peripheral speed of the sheet supply roller 15 is set from the start of the sheet supply roller 15 to the separation plate 1.
9 until just before the topmost sheet P1 tries to enter the sheet conveying path R due to the resistance force from 9 inches to 9 inches / second (about 76.2 mm / second) to 6 inches / second (about 152.
4 mm / sec) is desirable. When entering the sheet conveyance path R, the U-turn roller 21 is rotated to guide it between the conveyance roller 9 and the pinch roller 12, and thereafter, faces the recording head 3 while being sandwiched between the conveyance roller 9 and the pinch roller 12. It is conveyed to the platen 24 provided at the recording position. Next, the printing (image recording) operation by the recording head 3 mounted on the carrier 2 is started on the sheet P1 thus conveyed to the platen 24. Here, in the present embodiment, when the image recording for one scan (one movement along the guide shaft 7) by the recording head 3 is completed, the recording operation is temporarily stopped and the platen 2
The sheet P1 positioned on the sheet 4 is conveyed by the conveying roller 9 by a predetermined amount, and then the carrier 2 is again moved along the guide shaft 7 to perform image formation for the next one scan. Then, after the recording is sequentially performed by the recording head 3 on the platen 24, the sheet P is placed on the cassette cover 13 by the sheet discharge roller 25 and the spur 26 which is a rotary body which is rotated by contacting the sheet discharge roller 25. It is designed to be discharged to. In FIG. 1, reference numeral 11 represents a head recovery means,
The head recovery means 11 is provided at a position that can face the recording head 3 when the carrier 2 moves to a home position provided near one end of its movement range.
Then, the head recovery means 11 is operated during standby, before and after the recording operation, or between recordings for each row, and the recording head 3 is caused to perform operations such as capping and suction of the inkjet nozzles and wiping of the nozzle surface. As a result, clogging of the recording head 3 is prevented and the performance of the recording head 3 is maintained.

In the above-described embodiment, the ink jet type recording apparatus for ejecting recording of ink or the like onto the recording medium to perform recording has been described as an example, but the present invention is not limited to this and the sheet feeding apparatus of the present invention is applied. it can. Further, in the present embodiment, so-called serial type recording apparatus that records on the recording medium by alternately carrying the recording medium and moving the recording head in a direction intersecting the feeding direction of the recording medium. However, the present invention is not limited to this, and a recording head having a portion related to recording having a length equal to or longer than the width of the recording medium in the direction intersecting the recording medium feeding direction is used for recording. It may be used for a so-called line-type recording apparatus that records on a recording medium while intermittently conveying the medium.

[0021]

As described above, according to the present invention,
The sheet supply roller is rotatably held, and is fed by its own weight and the force of the rotation operation with an arm rotatably supported around a fulcrum located upstream of the sheet supply roller in the sheet conveying direction. In a sheet supply device for obtaining a roller pressure for a sheet, a rotational drive force from the drive source is applied to the sheet supply roller between a drive source for rotationally driving the sheet supply roller and the sheet supply roller. A delay means for delaying transmission for a predetermined time is provided. By this, before returning the sheet against the sheet feeding direction, the drive source is reversely rotated and the delay amount equal to or larger than the sheet returning amount is accumulated in the delay means, so that the sheet when returning the sheet is returned. By the frictional force generated between the sheet feeding roller and the sheet feeding roller, the sheet feeding roller can gyrate in the opposite direction to the sheet feeding direction by the delay amount accumulated in the delaying means. While the sheet supply roller is rotating around, the arm holding the sheet supply roller rotatably receives a downward motion force against the arm, and the sheet supply roller bites into the sheet and moves freely. It becomes possible to return the seat without any trouble.

[Brief description of drawings]

FIG. 1 is a perspective view of an inkjet printer which is an example of a recording apparatus including a sheet supply device according to an embodiment of the invention.

FIG. 2 is a cross-sectional view showing a schematic configuration of the inkjet printer of FIG.

FIG. 3 is a cross-sectional view showing the configuration of the sheet feeding device according to the embodiment of the present invention.

FIG. 4 is a perspective view showing a mechanical timer provided in the sheet feeding device shown in FIGS. 2 and 3.

[Explanation of symbols]

1 inkjet printer 1A Inkjet printer body 1B sheet feeding device 3 recording head 3A Image recording section 4 ink tank 5 Recording liquid supply tube 7 Guide shaft 6 frames 8 guide rails 9 Conveyor rollers 10 sheet supply cassette 11 Recovery means 12 pinch rollers 13 cassette cover 14 arms 14a Support point 15 Sheet supply roller 16 pulley 17 Belt 18 gears 19 Separation plate 20 Roller guide 21 U turn roller 22 Transmission gear (A) 22a, 23a abutting member 23 Transmission Gear (B) 24 Platen 25 sheet discharge roller 26 spur A mechanical timer mechanism P sheet

Claims (3)

[Claims] 1. A sheet supply roller is rotatably held,
An arm rotatably supported around a fulcrum located upstream of the sheet supply roller in the sheet supply direction;
A sheet supply device having a drive source for rotationally driving the sheet supply roller, wherein a roller pressure for a sheet to be fed is obtained by the weight of the arm and a force of a rotational operation, wherein the drive source and the sheet supply A sheet feeding device, characterized in that a delay means for delaying and transmitting a rotational driving force from the driving source to the sheet feeding roller by a predetermined time is provided between the sheet feeding roller and the roller. 2. When the sheet is returned in the direction opposite to the sheet feeding direction, a delay amount equal to or greater than the amount of returning the sheet is accumulated in the delay means prior to the operation of returning the sheet. Sheet feeding device. 3. A recording apparatus for recording an image on a sheet fed by the sheet feeding apparatus according to claim 1.