JP2002249247A - Sheet feeding device and image recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding device capable of always realizing stable sheet feeding by adjusting pressure contact force to the sheet surface of a feed roller, and an image recording device using it. SOLUTION: A paper feeding arm spring 53 to reduce the pressure contact force of a paper feeding roller 10 in response to the height of the sheet surface is mounted to a paper feeding arm 40 to movably support the paper feeding roller 10 in conformity with the height of the sheet surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for recording an image on a sheet separated and fed from a stacked sheet bundle, and is preferably applicable to such an image recording apparatus. The present invention relates to a sheet feeding device.

[0002]

2. Description of the Related Art Conventionally, as this type of image recording apparatus,
For example, an ink jet recording apparatus having a configuration as shown in FIG. 15 is known.

A sheet 1001 as a recording medium is loaded and accommodated in a cassette 1002. A paper feed roller 1003 rotatably supported by a paper feed arm 1004 is provided in an opening above the cassette 1002. The paper feed arm 1004 is rotated about a rotation fulcrum 1005,
The sheet feeding roller 1003 is configured to contact and separate from the sheet 1001. FIG. 15 shows a standby state before the start of sheet feeding.
005 is rotated counterclockwise in the figure. As a result, the sheet feeding roller 1003 is separated from the sheet 1001. 1006 in FIG.
01 is a cassette cover for protecting dust 01 from dirt and the like.

[0004] From the cassette 1002 to the paper feed roller 1003
The sheet 1001 pulled out by the sheet feeder is fed by a U-turn roller 1007 forming a transport path and a sheet feed guide 1008.
Guided between. Further, via the U-turn roller 1007 and the jam processing cover 1009, and via the U-turn roller 1007 and the pinch roller guide 1010,
It is guided between the paper transport roller 1011 and the pinch roller 1012. The sheet 1001 that has been jammed near the U-turn roller 1007 is removed by opening the jam processing cover 1009 in the direction of the arrow in the figure.

[0005] The platen 10 is moved by the paper conveying roller 1011.
13 is conveyed to the carriage 101
Printing is performed by the recording head 1015 mounted on the recording head 4. While the carriage 1014 moves along the guide shaft 1016 and the sub guide shaft 1017 in the direction perpendicular to the plane of FIG. 15, printing is performed by the recording head 1015.

[0006] The printed sheet 1001 is a sheet discharge roller 10
18 and the paper ejection pressing roller 1019, and is guided to the paper ejection stack 1020 to complete the paper ejection operation.

FIGS. 16 and 17 show a state in which the sheet feeding operation is being performed. The sheet feeding arm 1004 is rotated clockwise about a rotation fulcrum 1005 from the standby state shown in FIG. The sheet feeding roller 1003 is in a state of contacting the sheet surface of the sheet 1001. Note that FIG. 16 shows a state where the stacking amount of the sheet 1001 is large, and FIG. 17 shows a state where the stacking amount is small.

[0008]

By the way, in the above configuration, the paper feed roller 1003 is rotated by the angle between the paper feed arm 1004 and the sheet surface to feed the sheet 1001 when the sheet 1001 is fed. It is known that the pressing force (biting force) of the roller 1003 changes.

This is because the component force in the direction perpendicular to the sheet feeding arm 1004 of the frictional resistance that the sheet feeding roller 1003 receives from the sheet surface acts on the sheet feeding arm 40 as a rotating moment. Is pressed against the sheet surface.

As shown in FIG. 16, when the stacking amount of the sheet 1001 is large and the height of the sheet surface is high, the sheet feeding arm 100
Since the angle between the sheet 4 and the sheet surface is small, the pressing force is relatively small, and the pressing force of the sheet feeding roller 1003 is also small. On the other hand, FIG.
When the stacking amount of the sheet 1001 is small and the height of the sheet surface is low as in 7, the angle between the sheet feeding arm 1004 and the sheet surface increases, so that the pressing force increases and the pressing force of the sheet feeding roller 1003 increases. .

If the change in the pressing force due to the difference in the stacking amount is large, a problem may occur in sheet feeding. For example, if the pressing force is too small, a paper feeding error is caused. Conversely, if the pressing force is too large, the load on the sheet increases, which causes damage to the sheet.

In order to solve this problem, the distance from the sheet feeding roller 1003 to the rotation fulcrum 1005 is set to be considerably large, and the angle between the sheet feeding arm 1004 and the sheet surface is not so large even when the stacking amount of the sheet 1001 changes. There are ways to keep it from changing. However, if the sheet feeding arm 1004 is made larger in this way, the size of the entire apparatus becomes larger, which causes a problem of further cost increase.

Further, the above-mentioned conventional configuration has the following problems. That is, as shown in FIG.
16 and FIG.
It takes a predetermined time to shift to the contact state between the sheet feeding roller 1003 and the sheet 1001 as shown in (1), which increases the total printing time. In particular, when printing is continuously performed on a plurality of sheets, the sheet feeding roller 1003 must be moved each time a sheet is fed.
The above time loss is a serious problem.

Furthermore, the driving sound of the paper feed arm 1004,
There is also a problem that an impact sound or the like occurs when the sheet feeding roller 1003 comes into contact with the sheet 1001.

The present invention has been made in view of such circumstances, and an object of the present invention is to adjust a pressing force of a feeding roller against a sheet surface to always realize stable sheet feeding. An object of the present invention is to provide a sheet feeding device and an image recording device.

[0016]

In order to achieve the above object, according to the present invention, there is provided a feed roller for contacting a sheet surface of the uppermost sheet of a sheet bundle and feeding the sheet, A support member for movably supporting the feed roller in accordance with the height of the sheet surface; and a sheet feeding device comprising: a pressing force adjusting means for reducing a pressing force of the feeding roller. I do.

The pressing force adjusting means may reduce the pressing force of the feed roller according to the height of the sheet surface, and adjust the pressing force to be substantially constant regardless of the height of the sheet surface.

It is preferable that the supporting member is provided so as to be swingable, and the feeding roller is rotated in a direction in which the sheet is fed so as to move away from a swing supporting point of the supporting member.

It is preferable that the pressing force adjusting means urges the support member in a direction in which the feed roller is separated from a sheet surface.

The supporting member may cause the feed roller to abut against the sheet surface by its own weight, and the pressing force adjusting means may urge the supporting member in a direction against the own weight of the supporting member.

[0021] The pressing force adjusting means may be a coil spring that pulls the support member upward.

Preferably, the coil spring is disposed substantially above the feed roller.

It is preferable that a plurality of the feed rollers are provided in the sheet width direction, and the coil spring is disposed substantially above each of the plurality of feed rollers.

[0024] It is preferable that the press-contact force adjusting means is a torsion coil spring provided at a swing fulcrum of the support member.

Further, an image recording apparatus according to the present invention includes the above-mentioned sheet feeding apparatus, and recording means for recording an image on a sheet fed by the sheet feeding apparatus.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a tube supply type ink jet recording apparatus will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view showing the overall configuration of a tube supply type ink jet recording apparatus according to a typical embodiment of the present invention (with an outer cover removed).
2 is a cross-sectional view showing a schematic configuration of the recording apparatus shown in FIG. 1 as viewed from the lateral direction, and FIG. 3 is a plan view of the recording apparatus shown in FIG. 1 as viewed from above. FIG. 4 is an enlarged view of a main part of the overall plan view shown in FIG.

First, the outline of the mechanism of a tube supply type ink jet recording apparatus according to an embodiment of the present invention will be sequentially described with reference to FIGS.

An ink tube 3 extending from an ink tank 2 for supplying ink to the recording head 1 serving as recording means in this embodiment is connected to the recording head 1.

The recording head 1 is provided with a means for generating thermal energy as energy used for ejecting ink, particularly in an ink jet recording system, and employs a system in which a change in the state of ink is caused by the thermal energy. By using this, high density recording and high definition recording are achieved.

As shown in FIG. 2, the recording head 1 is mounted on the carriage 4 in a posture for discharging ink toward the sheet 6. Then, ink droplets are ejected while moving the carriage 4 in the main scanning direction along the guide shaft 5 to form an image on a sheet 6 such as recording paper. The carriage pulley 13 is driven by the rotation of the carriage motor 12, and the carriage 4 moves left and right (reciprocates) via the timing belt 25.

The recording head 1 mounted on the carriage 4 is connected to the ink tank 2 by an ink tube 3 extending from the ink tank 2, and the ink is constantly supplied from the tank. In this embodiment, as shown in FIG. 1, the ink tank 2 has four color ink cartridges 2a, 2a.
b, 2c and 2d. The four color ink cartridges 2a to 2d are of a type that can be replaced independently. The recording head 1 is also composed of recording heads of four colors. The ink tubes 3 are also formed of four tubes, and are configured to supply the above-described four colors of ink, respectively.

The sheets 6 separated and fed one by one from the sheet bundle accommodated in the cassette 9 installed at the lower part of the apparatus by the paper feed roller 10 to the transport roller 8 via the U-turn transport path 11. Is carried. The sheet 6 is conveyed between the platen 7 and the recording head 1 while being nipped by the pair of rollers of the conveying roller 8 and the discharge roller 23.

At this time, the sheet 6 is transported intermittently by a transport amount corresponding to one scan of the recording head 1. That is, when recording for one scan is completed by the recording head 1, the recording operation is temporarily stopped, and the sheet located on the platen 7 is driven by a feed motor (not shown) by a predetermined amount in the sub-scanning direction by the conveying roller 8. Then, the carriage 4 is again moved in the main scanning direction along the guide shaft 5 to form an image for the next one scan.

The sheet 6 on which the image is formed as described above is
After the printing is completed, the paper is discharged from the platen 7 toward the upper surface of the cassette 9 by the paper discharge roller 23.

On the right side of the main body of the apparatus, there is provided a recovery device 1 for performing a recovery operation for maintaining a good ink discharge state of the recording head 1.
The recovery device 14 has a cap 15 for capping the recording head 1, a wiper 16 for wiping the ink ejection surface of the recording head 1, and a device for sucking ink from the ink ejection nozzles of the recording head 1. , Etc. are provided.

The lower case 27 covering the lower surface of the apparatus main body is provided with a jam processing opening 56. The jam processing opening 56 is disposed substantially below the paper feed roller 10 and the transport roller 46, and is closed by the lower surface of the cassette 9 when the cassette 9 is mounted. If a jam occurs during sheet feeding or conveyance, the cassette 9 can be pulled out to easily perform the jam processing.

Guide shaft 5, platen 7, and transport roller 8
As shown in FIG. 3, a control board 18 of the recording apparatus is installed on the back side of the chassis 17 on which the is mounted. An interface for inputting a recording signal, M
RO for storing control programs executed by PU and MPU
M and a DRAM for storing various data are mounted.

A power supply 19 for supplying power for operating the control board 18 of the recording apparatus is provided on the left side of the apparatus main body. Power supply cable 2 from power supply 19
0, power is supplied to the control board 18 described above. Further, from the control board 18, for example, a signal for driving the recording head 1, a recording head flexible cable 21 for supplying power and the like, a signal for driving the recovery device 14, and a recovery device driving cable for supplying power 22 and so on.

The printhead flexible cable 21 is mounted on the carriage 4 from the control board 18 through the chassis 17 and is electrically connected to the printhead 1. As shown in FIGS. 3 and 4, an ink tube 3 is connected to the front of the recording head 1 and a recording head flexible cable 21 is connected to the rear. It is divided by.

A panel operation section 24 is provided above the power supply 19, and serves as a portion for displaying the operation of the apparatus user and the state of the apparatus.

FIGS. 5 and 6 are perspective views showing the entire appearance of the ink jet recording apparatus of the present embodiment. FIG. 5 shows a normal use state, and FIG. It is a figure showing a state.

The above-mentioned mechanism incorporated on the lower case 27 is entirely covered by the upper case 26. The panel operation unit 24 described above with reference to FIGS. 1 to 4 appears in the upper left portion of the recording apparatus.

The cassette 9 is also mounted on the recording apparatus so as to protrude from the upper case 26 and the lower case 27.
Incidentally, the upper surface of the cassette 9 is covered with a cassette cover 32, and the paper is discharged onto the cassette cover 32. When the length of the sheet discharged onto the cassette cover 32 is short, the discharge cover 29 is opened and taken out. FIG. 6 is a view showing a state where the discharge cover 29 is opened.

As shown in FIG. 6, when the discharge cover 29 is opened, the manual feed lever 30 can be operated. By pulling up the handle portion in front of the fulcrum about the manual feed lever rotation fulcrum 31, it becomes possible to insert a manual feed sheet (to be described in detail later).

The replacement of the ink tank 2 described above with reference to FIGS. 1 to 4 is performed by opening the ink tank cover 28.

FIGS. 5 and 6 show an ink jet recording apparatus corresponding to an A3 size sheet.
As a modified example, a recording apparatus corresponding to, for example, an A4 or letter size sheet is shown in FIGS.

The cassette 9 is accommodated in the front line of the entire apparatus without protruding from the upper case 26. Since the depth of the entire apparatus is short, the manual feed lever 30 is attached to the discharge cover 2.
9 is in a position where it can be seen even when it is not opened, but when performing manual feeding, it is performed with the discharge cover 29 opened.

Next, the main part of the tube type ink jet recording apparatus of the present embodiment will be described in detail with reference to FIG. FIG. 9 is a cross-sectional view of a main part showing a schematic configuration of the ink jet recording apparatus of the present embodiment.

The recording head 1 mounted on the carriage 4 includes an electric contact portion 33 and an ink joint portion 34, and the electric contact portion 33 and the ink joint portion 34 are provided at opposing positions.

By inserting the tube joint 35 connected to the ink tube 3 in the direction of the arrow in the figure, the tube joint 35 can be connected to the above-described ink joint portion 34, and the ink in the ink tank 2 is always supplied to the recording head 1. It becomes possible to supply.

On the other hand, the head connector 37 provided on the carriage board 36 mounted on the carriage 4 is pressed against the above-mentioned electrical contact portion 33 of the recording head 1 to establish electrical continuity. A flexible connector 38 is also provided on the carriage board 36, and the printhead flexible cable 2
It is connected to 1.

The recording head 1 is detachably mounted on the carriage 4, and the tube joint 35 is first pressed and inserted from the rear in a state where the electric conduction is established. Since the insertion direction coincides with the pressing direction of the electrical connection, there is no adverse effect on the previously connected electrical connection.

A sheet feeding section is disposed below the recording means having the above-described configuration. The sheet feeding unit generally includes a cassette 9 for storing sheets, and a paper feed roller 10 for feeding sheets from a sheet bundle stored in the cassette 9.
And a feed arm 4 that rotatably supports the feed roller 10
0.

The cassette 9 is provided detachably with respect to the recording apparatus main body. A portion of the upper surface of the cassette 9 which is located outside the apparatus when the cassette 9 is mounted (the state shown in FIG. 9) is almost covered with the cassette cover 32, and dust or dirt enters the cassette 9. Has been prevented. On the other hand, a portion of the upper surface of the cassette 9 which is located inside the apparatus is not covered with the cassette cover 32, and serves as an opening for feeding sheets.

Above the opening, a paper feed arm 40 is swingably supported by a swing fulcrum 41 provided on the apparatus main body. The paper feed roller 10 is provided at the front end (the end in the sheet feeding direction) of the paper feed arm 40, and the end opposite to the swing fulcrum 41 is engaged with the action portion 39 of the manual feed lever 30. A corresponding release projection 42 is formed.

FIG. 9 shows a state in which the handle portion of the manual feed lever 30 shown in FIG. At this time, the action portion 39 of the manual feed lever 30 shown in FIG. 9 rotates downward, and pushes down the release protrusion 42 of the paper feed arm 40. Then, the paper feed arm 40
Is rotated counterclockwise about the swing fulcrum 41, and the paper feed roller 10 is separated from the sheet 6 set in the cassette 9. When attaching and detaching the cassette 9,
Alternatively, when a manual sheet is supplied, the manual feed lever 30 is operated in this way to separate the sheet feeding roller 10 to the retracted position (retracted state).

FIG. 10 shows a state in which the manual feed lever 30 is released. In this state, the paper feed roller 10 is always in contact with the uppermost surface of the sheet 6 in the cassette 9 (operating state) under the load of the paper feed arm 40.

In this operating state, when a signal for starting the sheet feeding operation is issued from a controller (not shown), the sheet feeding drive shaft 43 is rotationally driven by a driving source such as a motor.
The rotation driving force is transmitted via the first transmission gear 44 and the second transmission gear 45, so that the sheet feeding roller 10 rotates counterclockwise in the drawing and feeds out the sheet.
The sheet fed by the rotation of the paper feed roller 10 is bent at the leading end by abutting against the separation slope 59 of the cassette 9, and only the sheet that is in contact with the paper feed roller 10 is separated.

In order to increase the pressure contact force (biting force) of the paper feed roller 10, the paper feed roller 10 is rotated so as to feed the sheet away from the pivot 41, and the cassette 9 is fully loaded with sheets. In this state, it is preferable that the sheet supply arm 40 is set to be inclined with the sheet supply roller 10 down. This is for the following reason.

When the paper feed roller 10 rotates, a frictional resistance is received from the sheet surface. A component of the frictional resistance in a direction orthogonal to the paper feed arm 40 acts on the paper feed arm 40 as a rotational moment. This rotational moment acts as a force for rotating the paper feed arm 40 in the clockwise direction in the drawing, that is, a force for pressing the paper feed roller 10 against the sheet surface. In this way, by applying the pressing force to the paper feed roller 10 in addition to the load of the paper feed arm 40, the pressure contact force of the paper feed roller 10 can be increased, and a sufficient sheet conveying force can be secured. .

Incidentally, the pressing force due to the rotational moment changes depending on the angle between the sheet supply arm 40 and the sheet surface. That is, the angle is 0 when the angle between the sheet supply arm 40 and the sheet surface is 0 ° (parallel), and becomes maximum when the angle is 90 °. Therefore, when the sheet stacking amount of the cassette 9 increases or decreases, the pressing force of the sheet feeding roller 10 changes accordingly. This is also not preferable because it causes factors such as defective sheet feeding and sheet damage.

Therefore, in the present embodiment, the sheet feeding arm spring 53 is attached as a pressing force adjusting means, and the sheet feeding arm is moved in the direction against the load of the sheet feeding arm 40 (the direction in which the sheet feeding roller 10 is separated from the sheet surface). 40 are energized. The spring stiffness of the sheet feeding arm spring 53 may be set so as to generate a restoring force having substantially the same magnitude as the amount of change in the pressing force based on the angle change of the sheet feeding arm 40.

As a result, the pressure contact force of the paper feed roller 10 is appropriately reduced according to the change in the sheet stacking amount, and the pressure contact force of the paper feed roller 10 can be kept substantially constant regardless of the height of the sheet surface. It becomes possible. (The pressing force of the paper feed roller 10 does not need to be kept strictly constant, as long as it can be adjusted within a range that does not cause the above-described poor paper feed or sheet damage.)

In this embodiment, as shown in FIG. 11, a sheet feeding arm spring 53 is provided substantially above each sheet feeding roller 10.
Has been arranged. According to this configuration, since the right and left balance of the pressing force of the sheet feeding roller 10 against the sheet surface is improved, the sheet is sent out by the sheet feeding roller 10 and is separated from the separation slope 59.
The right and left abutment forces of the sheet hitting the sheet are almost the same, so that the separation property is improved, the skew is prevented from occurring, and the sheet can be stably fed.

As described above, since the paper feed roller 10 is always in contact with the sheet surface in the operating state, there is no need to mechanically raise and lower the paper feed arm 40 every time a paper feed operation is performed. A drive mechanism is not required and the configuration is simplified. Further, it is possible to eliminate a time loss required for elevating and lowering the sheet feeding arm 40, and to shorten a total printing time.
Further, the mechanical driving sound of the paper feed arm 40 and the paper feed roller 10
Since no impact sound is generated when the vehicle collides with the sheet surface, the device can be silenced.

In this embodiment, the sheet feeding arm spring 5
3, the sheet feeding arm 40 is pulled upward. However, as shown in FIG. 12, a screw coil spring 58 may be provided at the pivot 41 of the sheet feeding arm 40. According to this configuration, in addition to the above-described effects, there is an effect of further space saving.

Returning to FIG. 9, the configuration relating to the sheet conveyance and the printing operation will be described.

The sheet 6 separated and fed by the feed roller 10 is sent to the U-turn conveyance path 11. The U-turn transport path 11 is formed by an inner U-turn roller 46 and an outer U-turn guide 47, and guides the sheet 6 separated and supplied from the cassette 9 between the transport roller 8 and the pinch roller 48.

The paper feed roller 10 and the U-turn roller 4
6 is overlapped in the cross-sectional direction, and between the U-turn rollers 46 divided in the axial direction,
0 is arranged. For this reason, the cassette 9 can be inserted deep into the apparatus, and the cassette 9 can be inserted to a position covering substantially below the U-turn roller 46.

The sheet 6 sandwiched between the transport roller 8 and the pinch roller 48 is transported onto a platen 7 disposed substantially above the opening of the cassette 9. And the transport roller 8
The printing is performed by the recording head 1 while being intermittently conveyed by the pair of rollers of the paper discharge roller 23.

The platen 7 has a through hole through which ink droplets discharged from the recording head 1 can pass. Therefore, even if the ink is directly ejected onto the platen 7, the ink does not stay on the platen 7, and the back surface of the sheet is not stained. This makes it possible to perform preliminary ejection (printing ink on the platen 7 near the sheet side edge during printing to maintain the state of the recording head 1 in a good state) or printing without margins (printing over the sheet edge and the platen 7). ) Can be performed.

The sheet feeding arm 40 is provided with a flat ceiling 54 substantially parallel to the opening of the cassette 9 and a stack wall 55 orthogonal to the flat ceiling 54. Flat ceiling 5
Reference numeral 4 denotes an area substantially equal to or larger than the projection when the ink ejection range (or the platen 7) of the recording head 1 is vertically projected, and the ink droplets passing through the through holes of the platen 7 are Has the role of receiving. Further, the stack wall 55 separates the inside of the apparatus from the paper discharge stacking section,
This prevents ink mist and the like from being separated from the inside of the apparatus, and prevents dust and dirt from entering from outside the apparatus.

The flat ceiling portion 54 and the stack wall 55 cover the portion of the opening of the cassette 9 upstream of the sheet feeding roller 10 over the entire area in the sheet width direction, so that ink droplets or ink ejected from the recording head 1 are formed. Mist, dust, and the like can be prevented from falling onto the sheet 6 stored in the cassette 9. In addition, by providing these on the paper feed arm 40, it is possible to simplify the apparatus configuration and save space.

FIG. 13 shows a modification of the present embodiment, in which an absorber 57 for absorbing ink is provided above the flat ceiling of the paper feed arm 40. By providing an absorber 57 such as a sponge having excellent liquid absorbability, ink droplets passing through the platen 7 can be positively received.

Next, the configuration relating to the manual feeding and discharging operation of the sheet will be described.

FIG. 9 shows a state in which manual insertion is possible. A portion of the opening of the cassette 9 outside the stack wall 55 serves as a manual sheet supply port. That is, when performing manual sheet feeding, first, the manual feed lever 30 is operated to set the sheet feeding roller 10 in a retracted state, and then sheets are inserted into the cassette 9 from the supply port. When the manual feed lever 30 is released with the leading edge of the sheet abutting the separation slope 59 of the cassette 9, the paper feed roller 10 comes into contact with the manual feed sheet. Is performed.

The sheet feed arm 40 is provided with a sheet discharge stack lever 50 so as to protrude above the manual sheet supply port. The discharge stack lever 50 is made of a film-like flexible material. The discharge stack lever 50 is a rotation fulcrum 5
The stack lever spring 52 is attached to the sheet feed arm 40 so as to be rotatable around the center 1 and is urged to rotate clockwise in the drawing.

In the normal state (when no force is applied), the discharge stack lever 50 is inclined along the supply direction of the manual feed sheet. Plays a role,
The manual feed can be easily performed.

The discharge stack lever 50 also plays a role as a receiving member for receiving the sheet discharged from the discharge roller 23. The sheet on which an image has been recorded on the platen 7 is discharged from the discharge roller 23 and the discharge spur 49.
Is discharged out of the apparatus, and stacked on the cassette cover 32 and the discharge stack lever 50. At this time, the discharge stack lever 50 is bent by the weight of the sheet, and the sheets are easily stacked.

The urging force of the stack lever spring 52 for urging the paper discharge stack lever 50 is set to a weak urging force that balances when a predetermined number (several to ten and a few) of sheets are stacked. . FIG. 14 shows the discharge stack lever 5
FIG. 7 is a diagram illustrating a state in which the sheets are stacked at 0. When the stacking amount of the sheets discharged onto the cassette cover 32 and the discharge stack lever 50 by the discharge roller 23 and the discharge spur 49 becomes equal to or more than a predetermined number, the urging force of the stack lever spring 52 is applied to the sheet as shown in FIG. Due to the weight, the stack lever 50 is rotated counterclockwise to the height of the cassette cover 32.

As a result, it is possible to prevent the supply port of the manual sheet from being closed and to prevent the discharged sheet from being re-fed into the cassette 9, and to secure a sufficient stacking space for the discharged sheet. It becomes possible.

Further, since the paper discharge stacking portion is constituted by the paper supply arm 40 (the paper discharge stack lever 50) and the upper surface of the cassette cover 32, it is not necessary to separately provide a paper discharge stack, and the size of the entire apparatus is reduced. Can be reduced in size, and the cost can be further reduced.

In this embodiment, the sheet feeding arm 4
Although the movable paper discharge stack lever 50 is provided at 0, effects such as reduction in size of the apparatus and cost reduction can also be obtained by integrally forming a discharge stack protrusion member on the paper supply arm 40 itself. Alternatively, a member having the same function as the sheet discharge stack lever 50 may be attached to the cassette cover 32, the apparatus main body, or the like instead of the sheet supply arm 40. Such a receiving member does not necessarily need to be inclined along the feeding direction of the manual feed sheet. If the receiving member is provided with a predetermined step from the upper surface of the cassette cover 32 and projects above the feed port of the manual feed sheet, And the effect of preventing re-feeding of the discharge sheet is obtained. In this case, it is also preferable to provide a rib or the like for guiding the sheet on the lower surface of the receiving member.

In this embodiment, the sheet accommodating means is constituted by the detachable cassette 9, but may be constituted by a sheet accommodating portion fixed to the apparatus body.

In this embodiment, only an example in which the present invention is applied to a tube supply type ink jet recording apparatus has been described. However, other types of ink jet recording apparatuses, electrophotographic / electrostatic recording type image recording apparatuses, and the like have been described. It can also be suitably applied. The image recording apparatus can be applied not only to a printer but also to a facsimile, a copying machine, etc., and is particularly suitable for a small-sized image recording apparatus.

[0087]

As described above, according to the present invention,
Since the pressing force adjusting means for reducing the pressing force of the feeding roller in accordance with the height of the sheet surface is provided, the sheet can always be stably fed regardless of the height of the sheet surface.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of an image recording apparatus (with an outer cover removed) according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a schematic configuration of the image recording apparatus of FIG.

FIG. 3 is a plan view showing the overall configuration of the image recording apparatus of FIG.

FIG. 4 is a plan view showing a configuration of a main part of FIG. 3;

FIG. 5 is a perspective view showing the overall configuration of the external appearance of the image recording apparatus according to the embodiment of the present invention.

FIG. 6 is a perspective view showing a state of the image recording apparatus of FIG. 5 at the time of a manual insertion operation or at the time of paper ejection.

FIG. 7 is a perspective view illustrating an overall configuration of an external appearance of an image recording apparatus according to another embodiment of the present invention.

FIG. 8 is a perspective view showing a state of the image recording apparatus of FIG. 7 at the time of a manual insertion operation or at the time of paper ejection.

FIG. 9 is a cross-sectional view illustrating a schematic configuration of a main part of the image recording apparatus according to the embodiment of the present invention.

FIG. 10 is a diagram for explaining an operation of a sheet feeding arm of the image recording apparatus of FIG. 9;

11 is a perspective view illustrating a configuration of a main part of the image recording apparatus of FIG. 9;

FIG. 12 is a cross-sectional view illustrating a schematic configuration of a sheet feeding arm of an image recording apparatus according to another embodiment of the present invention.

FIG. 13 is a cross-sectional view illustrating a schematic configuration of a sheet feeding arm of an image recording apparatus according to another embodiment of the present invention.

FIG. 14 is a view for explaining the operation of a paper discharge stack lever of the image recording apparatus of FIG. 9;

FIG. 15 is a cross-sectional view illustrating a schematic configuration of a main part of a conventional image recording apparatus.

FIG. 16 is a view for explaining the operation of a paper feed arm of a conventional image recording apparatus, and shows a state where a large number of sheets are stacked.

FIG. 17 is a view for explaining the operation of the paper feed arm of the conventional image recording apparatus, and shows a state where the sheet stacking amount is small.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 2 Ink tank 2a, 2b, 2c, 2d Ink cartridge 3 Ink tube 4 Carriage 5 Guide shaft 6 Sheet 7 Platen 8 Transport roller 9 Cassette 10 Paper feed roller 11 U-turn transport path 12 Carriage motor 13 Carriage pulley 14 Recovery device DESCRIPTION OF SYMBOLS 15 Cap 16 Wiper 17 Chassis 18 Control board 19 Power supply 20 Power supply cable 21 Recording head flexible cable 22 Recovery device drive cable 23 Discharge roller 24 Panel operation unit 25 Timing belt 26 Upper case 27 Lower case 28 Ink tank cover 29 Discharge cover REFERENCE SIGNS LIST 30 manual feed lever 31 manual feed lever rotation fulcrum 32 cassette cover 33 electrical contact part 34 ink joint part 35 tube joint 36 carriage board 37 Feed connector 38 flexible connector 39 manual feed lever action section 40 paper feed arm 41 paper feed arm swing fulcrum 42 paper feed arm release projection 43 paper feed drive shaft 44 first transmission gear 45 second transmission gear 46 U-turn roller 47 U Turn guide 48 Pinch roller 49 Discharge spur 50 Discharge stack lever 51 Rotation fulcrum of discharge stack lever 52 Stack lever spring 53 Feed arm spring 54 Flat ceiling of feed arm 55 Stack wall of feed arm 56 Jam opening 57 Absorber 58 Torsion coil spring 59 Separation slope

Claims (10)

[Claims] A feed roller that abuts on a sheet surface of an uppermost sheet of the sheet bundle and feeds the sheet; and a support member that movably supports the feed roller in accordance with the height of the sheet surface. And a press-contact force adjusting means for reducing the press-contact force of the feed roller. 2. The pressing force adjusting means reduces the pressing force of the feed roller according to the height of the sheet surface, and adjusts the pressing force to be substantially constant regardless of the height of the sheet surface. The sheet feeding device according to claim 1, wherein: 3. The apparatus according to claim 1, wherein the support member is provided so as to be swingable, and the feeding roller rotates in a direction in which the sheet is fed away from a swing support point of the support member. The sheet feeding device as described in the above. 4. A sheet according to claim 1, wherein said pressing force adjusting means urges said support member in a direction separating said feed roller from a sheet surface. Feeding device. 5. The apparatus according to claim 1, wherein the support member causes the feed roller to abut against a sheet surface by its own weight, and the pressing force adjusting means urges the support member in a direction against the own weight of the support member. Claims 1-3
The sheet feeding device according to any one of the above. 6. A sheet feeding apparatus according to claim 1, wherein said pressing force adjusting means is a coil spring for pulling said support member upward. 7. The sheet feeding device according to claim 6, wherein the coil spring is disposed substantially above the feeding roller. 8. The sheet according to claim 6, wherein a plurality of the feed rollers are provided in a sheet width direction, and the coil spring is disposed substantially above each of the plurality of feed rollers. Feeding device. 9. The sheet feeding apparatus according to claim 1, wherein said pressure contact force adjusting means is a torsion coil spring provided at a pivot of said support member. apparatus. 10. A sheet feeding apparatus according to claim 1, further comprising: recording means for recording an image on a sheet fed by the sheet feeding apparatus. Image recording device.