JP2001328730A - Paper feeder, copying machine, and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve separation performance while the height during feeding of the topmost paper of loaded transfer paper is about constant, in a paper feeder having a wide corresponding force to a kind of a transfer paper. SOLUTION: In the paper feeder 11 provided with a loading part 12 to load transfer papers S and a transporting mechanism 23 to transport a topmost paper sheet S1 of the transfer papers S in a paper feeding direction, the loading part 12 comprises a fixed part 13 inclined downward from the side situated upper stream to the side situated downstream of the paper feeding direction of the transfer sheet S; a movable part 14 rocking between a paper feed position, brought into inclination further equal to the horizontal than inclination of the fixed part and a separation position brought into inclination further equal to perpendicularity than inclination of the fixed part 13; and an elevating mechanism 25 exerting a drive force on the movable part 14 for turning between the paper feed position and the separation position. By this constitution, since the forward end part of the transfer paper S is raised and bent during paper feeding operation, each of the transfer paper S deviates at least the forward end part of the transfer paper S in a paper surface direction, and attractive force between the adjoining transfer papers S is weakened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder for separating and transferring sheet-like transfer sheets one by one or partly from a stacked state to an image forming apparatus provided in a copying machine, a printer, a facsimile, a printing machine or the like. It relates to a paper device.

[0002]

2. Description of the Related Art Generally, in various apparatuses such as a copying machine, a printer, a facsimile, and a printing machine, a main body having a plurality of trays capable of stacking a large amount of sheet-shaped transfer paper of the same size and type. It has a paper feeder. However, since the number of trays is limited, it is not possible to set all types of transfer sheets exceeding the number of trays. Therefore, several types of transfer papers that are mainly used are set in the tray, and a manual paper feeder provided separately from the main body paper feeder should be used for feeding other types of transfer papers. become. Conventionally, a manual paper feeder is generally provided in various apparatuses such as a copying machine, a printer, a facsimile, and a printing machine, similarly to the main body paper feeder.

[0003] The manual feeder is not limited to regular plain paper, but also includes postcards and OH which cannot be fed by the main body feeder.
Since it is also used for feeding special transfer paper such as P paper, thick paper, and paper, a wide range of responsiveness to transfer paper types is required.

For this reason, a FRR (Feed & Reverse Roller) system, which has excellent separation performance, is often used in a manual sheet feeding device. However, even then, when separating transfer paper having a large adhesion between transfer papers such as cotton paper, inconveniences such as double feeding and non-feeding may occur.

To solve this problem, Japanese Patent Laid-Open No.
The technology described in US Pat. No. 2,634,447 has been devised. One example based on this technique is shown in FIG.

First, a depression 2 is formed in a surface of the tray 1 on which the transfer sheets S are stacked, on the side on which the transfer sheets S are stacked. At a position facing the surface of the tray 1 on which the transfer sheets S are stacked, a pickup roller 3 that applies a force in the sheet feeding direction to the top sheet S1 of the transfer sheets S stacked on the tray 1 is provided. I have. The pickup roller 3 is provided movably in a direction approaching and separating from the tray 1.
When the paper is fed, it moves in the direction close to the tray 1 to
After the top sheet S1 has been fed, the sheet moves in a direction away from the tray 1 and separates from the transfer sheet S.

With such a structure, when the pickup roller 3 is pressed against the uppermost sheet S1 of the transfer sheets S stacked on the tray 1, the transfer sheet S is pressed against the dent 2, and the transfer sheet S moves along the dent 2. Since the transfer papers S are deflected, the transfer papers S are displaced in the paper surface direction, so that the adhesion between the transfer papers S is weakened and the transfer papers S are easily separated.

When the pickup roller 3 separates from the transfer sheet S after the top sheet S1 has been fed, the transfer sheet S
Are removed from the depression 2 by their waist, and each transfer paper S
In the direction of the paper surface of FIG.

As described above, in the example shown in FIG. 9, every time one sheet of transfer paper S is fed, each transfer paper S is shifted in the direction of the paper surface, thereby weakening the adhesion between the transfer papers S and separating the transfer papers S. It aims to make it easier.

[0010]

In recent years, it has been desired to increase the capacity of the manual sheet feeder, and the number of sheets has conventionally been increased from about 50 to about 100. There is a tendency.

However, in the example shown in FIG. 9, since a mechanism for raising and lowering the tray 1 is not provided, a large amount of transfer paper S cannot be stacked. This is because, in order to stack a large amount of the transfer paper S, a mechanism for raising and lowering the tray 1 in order to make the height of the top paper S1 substantially constant regardless of the remaining amount of the transfer paper S on the tray 1 is indispensable. Because it is.

An object of the present invention is to improve the separation performance of a paper feeder having a wide range of transfer paper types while keeping the height of the uppermost paper of the stacked transfer papers substantially constant when the paper is fed. With the goal.

Another object of the present invention is to provide a copier and a printer provided with a paper feeder having good separation performance.

[0014]

According to a first aspect of the present invention, there is provided a sheet feeding device, comprising: a stacking unit for stacking a plurality of transfer sheets; a stacking unit for stacking a plurality of transfer sheets; A transport mechanism that contacts the uppermost sheet of the stacked transfer sheets and conveys the uppermost sheet in the sheet feeding direction. A fixed portion that is inclined so as to descend toward the side, and is rotatably supported by this fixed portion or a member in the vicinity thereof. The top sheet swings between the paper feeding position at which the top sheet can be conveyed in contact with the conveyance mechanism and the separation position at which the top sheet is separated from the conveyance mechanism by a tilt that is closer to the vertical than the tilt of the fixed portion. A movable part, and the movable part is provided between the sheet feeding position and the separation position. And a lifting mechanism in giving driving force to rotate elevating the tip portion of the transfer sheet.

Therefore, when the movable portion is rotated by the elevating mechanism, the leading end portion of the transfer paper loaded on the loading portion supported by the movable portion is moved up and down, whereby the transfer paper bundle is moved to the separating position. In this case, the paper is bent so as to bend into a chevron and bend into a valley at the paper feed position. Can be

According to a second aspect of the present invention, in the paper feeder according to the first aspect, the transport mechanism stacks the transfer paper in the movable portion while the movable portion is located at the paper feed position. A pickup roller disposed at a position facing the loading surface to be pressed and pressed against the uppermost sheet in a state where the movable portion is located at the sheet feeding position, and at a position facing the pickup roller on the loading surface. Has a depression.

Accordingly, when the movable portion is located at the paper feeding position, the transfer sheet is bent by the rotation of the movable portion, and furthermore, is sandwiched between the pickup roller and the recess, and moves along the recess. Since the transfer paper is deflected, the displacement of the transfer paper in the paper surface direction can be increased, and the adhesion between the transfer papers can be further reduced.

According to a third aspect of the present invention, in the paper feeder according to the first aspect, the transfer mechanism stacks the transfer paper in the movable portion in a state where the movable portion is located at the paper feed position. A pickup roller disposed at a position facing the loading surface to be pressed and pressed against the uppermost sheet in a state where the movable portion is located at the sheet feeding position, and a portion of the loading surface facing the pickup roller is , And an elastic member formed of a material having elasticity.

Therefore, when the movable portion is located at the paper feed position, the transfer paper is bent by the rotation of the movable portion, and is further sandwiched between the pickup roller and the elastic member. Can be bent along the outer peripheral surface shape of the transfer paper, so that the displacement of the transfer paper in the paper surface direction can be increased, and the adhesion between the transfer papers can be further reduced.

According to a fourth aspect of the present invention, there is provided a copying machine according to the first, second, or third aspect, an image reading device for reading an image of a document, and an image reading device for forming an image of the document read by the image reading device. And an image forming apparatus for transferring the image onto the transfer sheet fed by the sheet feeding device.

Therefore, since the paper is fed to the image forming apparatus by the paper feeder that separates and feeds the transfer paper while weakening the adhesion between the transfer papers, errors such as double feed and non-feed of the transfer paper hardly occur.

According to a fifth aspect of the present invention, there is provided a printer according to the first, second, or third aspect, an interface for receiving data input from an external device, and print data input through the interface. And an image forming apparatus for forming an image to be printed and transferring the image to the transfer sheet fed by the sheet feeding device.

Accordingly, since the paper is fed to the image forming apparatus by the paper feeder which separates and feeds the transfer paper with weak adhesion between the transfer papers, errors such as double feed and non-feed of the transfer paper hardly occur.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view showing a schematic structure of the sheet feeding device 11, FIG. 2 is a longitudinal sectional view showing the sheet feeding device 11 during a sheet feeding operation, and FIG.
FIG. 4 is a longitudinal sectional view showing the sheet feeding device 11 after the last transfer sheet S has been sent out.

Such a paper feeding device 11 is used in various devices such as a copying machine, a printer, a facsimile, and a printing machine.
The sheet-like transfer paper S is provided upstream of the image forming apparatus provided therein in the paper feeding direction, and is used to feed and convey the sheet-shaped transfer paper S to the image forming apparatus after separating one by one or a part from the stacked state.

The printer 110 accepts data input from an external device such as a personal computer and the paper feeding device 11 of the present embodiment provided as a manual paper feeding device, for example, as shown in the schematic diagram of FIG. An interface 111 and a printer unit 112 as an image forming apparatus for forming an image to be printed based on print data input through the interface 111 and transferring the image to transfer paper.

As shown in a schematic diagram of FIG. 5, for example, the copying machine 120 includes a sheet feeding device 11 of the present embodiment provided as a manual sheet feeding device and a scanner as an image reading device for reading an image of a document. And a printer unit 122 as an image forming apparatus that forms an image of a document read by the scanner unit 121 and transfers the image to a transfer sheet.

The facsimile machine 130 is, for example, as shown in FIG. 6A and FIG.
And a scanner unit 131 for reading the image of the original, transmitting the image data of the original read by the scanner unit 131 via the communication line 132, and transmitting the image data of the original transmitted from another location via the communication line. And a printer unit 1 that forms an image of a document based on data received by the transmitting and receiving device 133 and transfers the image to transfer paper
34.

Here, the printer units 112, 122, 13
Examples of the image forming method 4 include a laser method, an ink jet method, a sublimation type thermal transfer method, a silver halide photographic method, a direct thermal recording (TA = Thermo-Autochrome) method, and a fusion type thermal transfer method.

Alternatively, if provided in a printing press,
The paper feeding device 11 separates and feeds the transfer paper to a stencil printing device (not shown) as an image forming device. A stencil printing device is well known, and applies transfer paper to one surface of a master made from an image of a document and supplies ink from the other surface,
An image is formed on transfer paper with ink that has passed through the master.

The paper feeding device 11 has a tray 12 as a loading portion.
have. The tray 12 includes a fixed part 13 and a movable part 14.
Consists of The fixing portion 13 is fixed in a state of being inclined so as to descend from the upstream side in the paper feeding direction to the downstream side. The movable portion 14 is rotatably supported at the upstream end by a support shaft 15 in the vicinity of the downstream end of the fixed portion 13. As shown in FIG. 3, the movable portion 14 is substantially horizontal without the transfer paper S.

Here, the state shown in FIG. 1 is a state where the movable part 14 is located at the separation position, and the state shown in FIGS. 2 and 3 is a state where the movable part 14 is located at the sheet feeding position. .

A pair of guide members 16 are provided on the surface of the fixed portion 13 on the side where the transfer paper S is stacked. The guide member 16 is attached to a rack and pinion structure (not shown), is symmetrically movable in directions approaching and moving away from each other, and is used in contact with a side edge of the transfer sheet S to be used. Is regulated in the width direction.

On the downstream side of the guide member 16, there is formed a restricting portion 17 which protrudes from the upper end edge of the guide member 16 onto the transfer paper S and regulates the stacking amount of the transfer paper S. On the upstream side of the guide member, there is formed an introduction portion 18 that projects from the stacking surface 13a on which the transfer paper S is stacked to the transfer paper S more than the regulation portion 17, and the introduction portion 18 and the regulation portion 17 are formed. Are connected by a guide portion 19. With the introduction unit 18 and the guide unit 19, the transfer paper S
By sliding the bundle to the downstream side, the both ends of the transfer paper S can be easily inserted between the regulating portion 17 and the stacking surface 13a.

A pickup roller 20 is provided at a position of the movable section 14 facing the loading surface 14a on which the transfer paper S is loaded. The pickup roller 20 is rotatably provided, and is rotatably driven in a sheet feeding direction by a driving mechanism such as a motor (not shown), so that the uppermost sheet S
1 to the paper feed direction.

A feed roller 21 and a reverse roller 22 that presses against the feed roller 21 are disposed in the direction in which the top sheet S1 advances.

The feed roller 21 is rotatably provided, and is driven to rotate in the sheet feeding direction by a driving mechanism such as a motor (not shown), so that the pickup roller 2 is rotated.
The uppermost sheet S1 fed by 0 is further fed in the sheet feeding direction.

The reverse roller 22 is rotatably provided, and is connected via a torque limiter (not shown) to a drive mechanism such as a motor (not shown) for applying a rotational driving force in the direction opposite to the sheet feeding direction. Therefore, it receives the rotational driving force in the sheet feeding direction limited to a predetermined value or less.

The magnitude of the rotational force of the reverse roller 22 limited by the torque limiter is determined when the reverse roller 22 is in direct contact with the feed roller 21 and between the feed roller 21 and the reverse roller 22 when one transfer is performed. Paper S
When the transfer paper S is sandwiched between the feed roller 21 and the reverse roller 22, when the transfer paper S is sandwiched between the feed roller 21 and the reverse roller 22, the transfer paper S It is large enough to rotate in the direction opposite to the sheet feeding direction and feed back the lower-order transfer sheet S other than the top sheet S1 until it becomes only

Here, the pickup roller 20, the feed roller 21, and the reverse roller 22 constitute a transport mechanism 23. Reverse roller 22 and movable part 1
4, a guide slope 24 is provided.

Below the tray 12, transfer is performed by applying a driving force to the movable portion 14 to rotate between a sheet feeding position (the state shown in FIGS. 2 and 3) and a separating position (the state shown in FIG. 1). An elevating mechanism 25 that elevates and lowers the leading end portion of the paper S is provided.

The elevating mechanism 25 includes a solenoid 27 for selectively positioning the protruding portion 26 at a position where the protruding portion 26 is protruded by the electromagnetic force and a position where the protruding portion 26 is retracted. And a lifting lever 30 in the shape of a letter.

One end 31 of the lifting lever 30 and the projection 2
6 is connected by a pressure spring 32.
The other end 33 of the lift lever 30 is in contact with the lower surface of the movable part 14.

In such a configuration, during the sheet feeding operation, the pickup roller 20, the feed roller 21, and the reverse roller 22 are driven to rotate by a driving mechanism such as a motor (not shown) from the state shown in FIG.

At this time, since the transfer paper S is not sandwiched between the feed roller 21 and the reverse roller 22,
The reverse roller 22 rotates together with the feed roller 21. At this time, the solenoid 27 is not energized, and the protruding portion 26 protrudes and is in a free state.

Next, the solenoid 27 is energized, and the projection 26 is retracted. Then, the end 31 of the lifting lever 30 is pulled through the pressing spring 32, and the lifting lever 3 is pulled.
0 rotates around the support shaft 29, and the other end 33 of the lift lever 30 rises.

When the end 33 of the lift lever 30 is raised, a force is applied to the lower surface of the movable portion 14 in the pushing direction, and the movable portion 14 rotates around the support shaft 15 and is positioned at the sheet feeding position. . As a result, the leading end portion of the transfer sheet S on the movable section 14 is pushed up, and the top sheet S1 comes into contact with the pickup roller 20 and reaches a position where the sheet can be fed.

Then, the uppermost sheet S1 moves in the sheet feeding direction due to the frictional force between the pickup roller 20 and the rotationally driven pickup roller 20. At this time, the lower transfer paper S may move in the paper feeding direction together with the movement of the uppermost paper S1 due to the frictional force between the uppermost paper S1 and the lower transfer paper S. When a transfer sheet S other than the top sheet S1 enters, the reverse roller 22 rotates in the direction opposite to the sheet feeding direction, so that the lower transfer sheet S is back-fed. That is, a plurality of transfer sheets S are prevented from being fed simultaneously.

Then, only the top sheet S1 is separated,
The sheet is sent to an image forming unit (not shown) downstream of the feed roller 21 and the reverse roller 22.

When the transfer of one transfer sheet S is completed, the power supply to the solenoid 27 is cut off, the projection 26 projects and becomes free, and the movable section 14 is rotated by its own weight to rotate the transfer sheet S. The tip descends. When a plurality of transfer sheets S are continuously fed, such as when a plurality of images are formed, the above operation is repeated.

According to the present embodiment, the loaded transfer paper S bends in a chevron shape at the separated position and a valley shape at the paper feed position by rotating the movable portion 14. Therefore, during the paper feeding operation, the leading end of the stacked transfer papers S is shifted in the paper surface direction, so that the adhesion between the transfer papers S is weakened at least at the leading end, and the separating performance is improved.

Next, a second embodiment of the present invention will be described with reference to FIG. In the description of this embodiment, the same portions as those described in the previous embodiment will not be described in detail, and will be denoted by the same reference numerals (the same applies to the following embodiments).

FIG. 7 is a longitudinal sectional view showing a schematic structure of the sheet feeding device 41 of the present embodiment. The paper feeding device 41 is provided with the pickup roller 20 on the loading surface 14 a of the movable portion 14.
The recess 42 is formed at a position facing the.

In such a configuration, when the movable section 14 is located at the paper feed position, the transfer paper S is sandwiched between the pickup roller 20 and the depression 42. Then, as shown in the drawing, the transfer paper S bends along the depression 42, so that the deviation of each transfer paper S in the paper surface direction can be increased.

Therefore, the adhesion between the transfer sheets S can be further reduced, and the separation performance can be further improved.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a longitudinal sectional view showing a schematic structure of the sheet feeding device 51 of the present embodiment. FIG. 8 shows the movable unit 1 without the transfer paper S loaded thereon.
4 shows a state in which No. 4 is positioned at a paper feeding position.

The paper feeding device 51 is provided on the loading surface 14 of the movable portion 14.
a at a position facing the pickup roller 20 in FIG.
A rubber plate 52 as an elastic member is embedded.

In such a configuration, when the movable section 14 is located at the paper feeding position, the transfer paper S is sandwiched between the pickup roller 20 and the rubber plate 52. Then, the transfer paper S pressed against the rubber plate 52 digs in and bends along the outer peripheral surface shape of the pickup roller 20. This makes it possible to increase the displacement of each transfer sheet S in the paper surface direction.

Therefore, the adhesion between the transfer sheets S can be further reduced, and the separation performance can be further improved.

In implementing the present invention, the elevating mechanism for rotating the movable part 14 is not limited to the elevating mechanism 25 exemplified in the first to third embodiments.

[0061]

According to the first aspect of the present invention, when the movable portion is rotated by the elevating mechanism, the leading end portion of the transfer paper loaded on the stacking portion supported by the movable portion is raised and lowered. As a result, the transfer paper bundle is bent so as to bend in a chevron shape at the separation position and to bend in a valley shape at the paper feed position, so that at least the leading end portion of the transfer paper is displaced in the paper surface direction. Therefore, the adhesion between the transfer sheets can be reduced, and the sheet is separated and fed from that state, so that the separation performance is improved, and the occurrence of double feed or non-feed can be made less likely to occur. In addition, according to such a configuration, when used as a manual paper feeder having a wide range of ability to cope with the type of transfer paper, the height at the time of feeding the uppermost paper of the stacked transfer paper is set to be substantially constant. can do.

According to the second aspect of the present invention, when the movable portion is located at the paper feed position, the transfer sheet is bent by the rotation of the movable portion and furthermore, the transfer roller is further moved by the pickup roller and the depression. Since the sheet is bent along the dent between the sheets, the displacement of the transfer sheet in the paper surface direction can be increased, and the adhesion between the transfer sheets can be further reduced. Therefore, the separation performance can be further improved, and the occurrence of double feed or non-feed can be further reduced.

According to the third aspect of the present invention, when the movable portion is located at the paper feed position, the transfer sheet is bent by the rotation of the movable portion and furthermore is elastically moved by the pickup roller and the elastic member. Since the sheet is bent between the members and along the outer peripheral surface shape of the pickup roller, the displacement of the transfer sheet in the paper surface direction can be increased, and the adhesion between the transfer sheets can be further reduced. Therefore, the separation performance can be further improved, and the occurrence of double feed or non-feed can be further reduced.

According to the fourth aspect of the present invention, the paper is fed to the image forming apparatus by the paper feeder that separates and feeds the transfer paper while weakening the adhesion between the transfer papers. It is possible to obtain a copying machine in which the occurrence of the copying is difficult.

According to the fifth aspect of the present invention, since the paper is fed to the image forming apparatus by the paper feeder which separates and feeds the transfer paper while weakening the adhesion between the transfer papers, errors such as double feed and non-feed of the transfer paper are caused. It is possible to make the printer less likely to cause the problem.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a schematic structure of a sheet feeding device according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing the sheet feeding device during a sheet feeding operation.

FIG. 3 is a longitudinal sectional view showing the sheet feeding device after the last transfer sheet has been sent out.

FIG. 4 is a schematic diagram illustrating a schematic configuration of a printer.

FIG. 5 is a schematic diagram showing a schematic configuration of a copying machine.

FIG. 6A is a schematic diagram showing a schematic configuration of a facsimile, and FIG. 6B is a block diagram schematically showing an electrical connection of each unit.

FIG. 7 is a longitudinal sectional view showing a schematic structure of a sheet feeding device according to a second embodiment of the present invention.

FIG. 8 is a longitudinal sectional view illustrating a schematic structure of a sheet feeding device according to a third embodiment of the present invention.

FIG. 9 is a longitudinal sectional view showing an example of a conventional sheet feeding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Paper feeder 12 Loading part 13 Fixed part 14 Movable part 14a Loading surface 20 Pickup roller 23 Transport mechanism 25 Elevating mechanism 42 Depression 52 Elastic member 110 Printer 111 Interface 112 Image forming device 120 Copying machine 121 Image reading device 122 Image forming device

Claims (5)

[Claims] 1. A stacking unit for stacking a plurality of transfer papers, and a transport mechanism for contacting the uppermost paper of the transfer paper stacked on the stacking unit and transporting the uppermost paper in a paper feeding direction. In the paper feeder provided, the stacking portion is rotatably supported by a fixed portion inclined so as to descend from the upstream side to the downstream side in the paper feeding direction of the transfer sheet, and a member near the fixed portion or a member in the vicinity thereof. Then, according to the rotation, the inclination becomes closer to the horizontal than the inclination of the fixed part, and the paper feed position at which the uppermost sheet can be transported in contact with the transport mechanism is closer to the vertical than the inclination of the fixed part. A movable portion that is inclined and swings between a separation position at which the uppermost sheet separates from the transport mechanism, and applies a driving force to the movable portion to rotate between the sheet feeding position and the separation position. A lifting mechanism for raising and lowering the leading end of the transfer paper Sheet feeding apparatus according to claim. 2. The transfer mechanism, wherein the movable unit is disposed at a position facing the loading surface of the movable unit on which the transfer paper is loaded in a state where the movable unit is located at the paper feed position, and the movable unit is provided with the movable unit. 2. The apparatus according to claim 1, further comprising: a pickup roller that presses the uppermost sheet in a state where the pickup roller is located at a sheet feeding position, and a depression is formed at a position of the stacking surface that faces the pickup roller. 3. Paper feeder. 3. The transport mechanism is disposed at a position opposite to a loading surface of the movable section on which the transfer paper is loaded, with the movable section being located at the paper feed position, and the movable section is provided with the movable section. A pickup roller that presses against the uppermost sheet in a state where the pickup roller is located at a sheet feeding position, and a portion of the loading surface facing the pickup roller is formed by an elastic member formed of an elastic material. The sheet feeding device according to claim 1, wherein 4. A sheet feeding device according to claim 1, 2 or 3, an image reading device for reading an image of a document, and an image of the document read by the image reading device is formed and fed by the sheet feeding device. And an image forming apparatus for transferring the image onto the transfer paper. 5. A paper feeder according to claim 1, 2 or 3, an interface for receiving data input from an external device, and an image to be printed based on print data input via the interface. And an image forming apparatus for transferring the image onto the transfer sheet fed by the sheet feeding device.